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7109 LAKE BALLINGER WAY.PDF11111111111111 11816 7109 LAKE BALLINGER WAY City of Edmonds Critical Area Notice of Decision Applicant: (' q U Property Owner: —r , e v Critical Area File #: efA _ Z o0 (` 0 ( O 0 Permit Number: Z O ( (_ O W Site Location: 6 Parcel Number: nb M0000 Project Description: w Sr (— 2 ❑ Conditional Waiver. No critical area report is required for the project described above. There will be no alteration of a Critical Area or its required buffer. The proposal is an allowed activity pursuant to ECDC 23.40.220, 23.50.220, and/or 23.80.040. The proposal is exempt pursuant to ECDC 23.40.230. ❑ Erosion Hazard. Project is within erosion hazard area. Applicant must prepare an erosion and sediment control plan in compliance with ECDC 18.30. Critical Area Report Required. The proposed project is within a critical area and/or a critical area buffer and a critical area report is required. A critical area report has been submitted and evaluated for compliance with the following criteria pursuant to ECDC 23.40.160: 1. The proposal minimizes the impact on critical areas in accordance with ECDC 23.40:120, Mitigation sequencing; 2. / The proposal does not pose an unreasonable threat to the public health, safety, or welfare on or off the development proposal site; 3. -X The proposal is consistent with the general purposes of this title and the public interest; 4. / Any alterations permitted to the critical area are mitigated in accordance with ECDC 23.40.110, Mitigation requirements. 5. l The proposal protects the critical area functions and values consistent with the best 6. /available science and results in no net loss of critical functions and values; and The proposal is consistent with other applicable regulations and standards. ❑ Unfavorable Critical Area Decision. The proposed project is not exempt or does not adequately mitigate its impacts on critical areas and/or does not comply with the criteria in ECDC 23.40.1.60 and the provisions of the City of Edmonds critical area regulations. See attached findings of noncompliance. Favorable Critical Area Decision. The proposed project as described above and as shown on the attached site plan meets or is exempt from the criteria in ECDC 23.40.160, Review Criteria, and complies with the applicable provisions of the City of Edmonds critical area regulations. Any subsequent changes to the proposal shall void this decision pending re -review of the proposal. Conditions. Critical Area specific condition(s) have been applied to the permit number referenced above. See referenced permit number for specific condition(s). Al-ke- C�jl �&'-\ Reviewer t-k2w-;;� Signature 3 /v Date Appeals: Any decision to approve, condition, or deny a development proposal or other activity based on the requirements of critical area regulations may be appealed according to, and as part of, the appeal procedure, if any, for the permit or approval involved. Revised 12/16/2010 PLANNING DATA SINGLE FAMILY RESIDENTIAL STREET FILE "�_�' l � J --qName: Date:_ l' Site Address: Q G I In Plan Check r : 11- r6� Project Description: N eev A"/10 a p s i Reduced Site Plan Provided: (YES /lam Zoning: Map Page: dl Corner Lot: (YES / 10 Flag Lot: (YES /60 Critical Areas Determination study Required ❑ Waiver SEPADetermination: AExempt ❑ Needed (for over 500 cubic yards of grading) ❑ Fee ❑ Checklist ❑ APO List with notarized form Required Setbacks Street: ' J Side-. 1 O de- SHIN l D e� _ Actual Setbacks Street: / Side: I �1_ Side: l Rear: 3 S 4- Detached Structures: Ck- ❑ Rockeries: ❑ Fences[Trellises: /ftl C ❑ Bay Windows/Projecting Modulation: �- Stairs/Deck: x t5Spy 45 CO(At Buildin Height Datum Point: Datum Elevation: Maximum Height Allowed: Zs (317 :T Actual Height: 2 S 3 1 Other Parking Required: Z Parking Provided: Lot Area: Z o , U I � Maximum Lot Coverage: 35% � Proposed: / _ 7 Lot Coverage Calculations: ,f ADU Created: (YES / Add'(�o�ii� ��v('�X Cf 'I/A � � (/ ( e also t <m� Subdivision Legal Nonconforming Land Use Determination Issued: (YES / �VO c C Comments - f (o�� 5 Zq 6 x L� — 3 li X 6� Cu�r�9�t Z) �XrS r r��re c r 0.467Pon dr 7d; �� ; aGATcr, alto? AD 0 S . 10 Plan Review B � �Z y Nam" Data form 04-11-06.doc — IE X KING COUNTY 71 oq Z44 4 LV LL 3 17-9 IH SEC C4 cfl 17-25 17-24 17-22 SH F 88 SHORELINE 91 SHORELINE 90 SHORELINE 92 I - f WETLAND DELINEATION REPORT for the Trieu Property; 7109 Lake Ballinger Way Edmonds, Washington Prepared For: Frank Trieu 7109 Lake Ballinger Way Edmonds, WA 98026 Prepared BY: Ha�liixat E logy and Design, Inc. .Kevin Karlson 826 4�S- treet, Suite 202 Marysville, WA 98270 _ ho�360 65&9810� Fax: (360) • 51c-7252 December 28, 2011 HEDI Project #1„1 f§ , B FEB 2 3 2012 SUILDING CI-TyOFEDMON $ STREET File Contents 1.0 INTRODUCTION.................................................................................................................... 4 1.1 PURPOSE................................................................................................................................. 4 1.2 SITE DESCRIPTION.................................................................................................................. 4 1.3 CLIMATE AND GROWING SEASON..........................................................................................4 1.3.1 Growing Season.............................................................................................................. 4 1.4 DEFINITIONS........................................................................................................................... 4 1.4.1 Wetlands......................................................................................................................... 4 1.4.2 Buffers............................................................................................................................ 5 2.0 METHODS................................................................................................................................5 2.1 OFFICE RESEARCH..................................................................................................................5 2.2 SITE INVESTIGATION..............................................................................................................6 2.3 WETLAND DETERMINATION...................................................................................................6 2.3.1 Vegetation.......................................................................................................................6 2.3.2 Hydrology.......................................................................................................................6 2.3.3 Soil.................................................................................................................................. 6 2.4 OFF -SITE EVALUATION OF CRITICAL AREAS AND BUFFERS .................................................. 7 3.0 RESULTS..................................................................................................................................7 3.1 SITE INVESTIGATION..............................................................................................................7 3.1.1 Wetland A....................................................................................................................... 7 3.2 STREAMS.................................................................................................................................8 3.3 OFF -SITE EVALUATION OF CRITICAL AREAS AND BUFFERS .................................................. 8 3.4 FUNCTIONS AND VALUES....................................................................................................... 8 4.0 PROPOSED DEVELOPMENT ACTIVITIES......................................................................8 4.1 PROPOSED MITIGATION.......................................................................................................... 8 5.0 CONCLUSIONS.......................................................................................................................8 6.0 DISCLAIMER..........................................................................................................................9 7.0 REFERENCES.......................................................................................................................10 APPENDIX A: MAPS AND FIGURES..........................................................................................11 LocationMap............................................................................................................................... II AerialPhotograph........................................................................................................................12 Mapped Wetlands and Streams....................................................................................................13 Soiland Topographic Map...........................................................................................................14 Critical Areas Delineation Sketch................................................................................................15 List of Tables TABLE 1: WETLAND A DETERMINATION SUMMARY............................................................................. 7 List of Figures FIGURE1: SITE LOCATION.................................................................................................................... 11 FIGURE 2: AERIAL PHOTOGRAPH......................................................................................................... 12 FIGURE 3: WETLANDS & HYDROLOGY MAP....................................................................................... 13 FIGURE 4: SOILS & TOPOGRAPHY MAP............................................................................................... 14 FIGURE 5: CRITICAL AREAS SKETCH................................................................................................... 15 FIGURE 6: WETLAND A INTERIOR........................................................................................................ 16 FIGURE7: WETLAND A LAKESHORE................................................................................................... 16 FIGURE 8: WETLAND A OFFSITE PONDING (WEST).............................................................................. 16 FIGURE 9: WETLAND A ONSITE BUFFER TO SOUTH............................................................................. 16 FIGURE 10: WETLAND A ONSITE BUFFER TO SOUTHWEST.................................................................. 16 Trieu Delineation 1.0 Introduction 1.1 Purpose Habitat Ecology and Design has prepared this wetland delineation report at the request of Frank. Trieu. This report serves to characterize existing wetlands on the subject property, which is located within City of Edmonds jurisdiction. The City of Edmonds regulates wetlands as outlined under the ECDC 23.50, and this report details on -site wetland designation, rating, and buffer requirements as detailed in ECDC 23.50.10 through 23.50.40. 1.2 Site Description The subject property is located at 7109 Lake Ballinger Way, City of Edmonds, Snohomish County (T27 R04 S32). The parcel number is 00488800800700, which accounts for approximately 0.63- acres (Figure 1). The subject property has been previously developed with a single family home, driveways, sports court, dock, and landscape improvements. No other additional buildings are located on the site. The remaining site area is dominated by mowed lawn and maintained landscaping. According to Snohomish County hydrology data no streams are present on -site (Figure 3). Snohomish County wetland maps indicate wetland areas on/near the site, and the NWI wetland inventory maps indicate wetland on the north portion of the site (Figure 3). According to the Soil Survey of Snohomish County Area, Alderwood gravelly sandy loam and Mukilteo muck make up the entire site area. According to the National Resources Conservation Service (NRCS) the Alderwood map unit is a non-hydric soil type and the Mukilteo muck soil type is a hydric soil. (Figure 4). 1.3 Climate and Growing Season 1.3.1 Growing Season The U.S. Department of Agriculture, Natural Resources Conservation Service defines the growing season as the portion of the year that soil temperature is greater than 41 °F (biological zero) at 19.7 inches below the soil surface. It is approximated by the last day in spring that air temperature reaches 28°F to the first day in autumn that air temperature drops to 28°F. The average number of growing days peaks in July; however, plant growth can occur at any time of year. Using data for the Everett WETS station, the growing season can be approximated for five years in ten (50% of the time) using the 28°F standard. Based on these criteria, the growing season at in the project vicinity occurs between March 14 and October 30. 1.4 Definitions 1.4.1 Wetlands Wetlands are generally defined as those areas that are inundated or saturated by surface or groundwater at a frequency and duration sufficient to support, and under normal circumstances do support, a prevalence of vegetation typically adapted for life in saturated soil conditions. Wetlands generally include swamps, marshes, bogs, wet meadows and similar areas (U.S. Army Corps of Engineers, 1987). Also included as wetlands are artificial wetlands intentionally created from non - wetland areas for mitigation or wetland banking. Wetlands do not normally include artificial wetlands intentionally created from non -wetland sites, consisting of, but not limited to, irrigation and drainage ditches, grass -lined or biofiltration swales, canals, detention facilities, wastewater treatment facilities, farm ponds, and landscaping amenities. December 28, 2011 Page 4 of 16 Prepared by: Habitat Ecology and Design, Inc HEDI Job #: 11-0045 Trieu Delineation 1.4.2 Buffers Under ECDC a buffer is defined as the area measured horizontally outward from a delineated critical area including wetlands; habitat conservation areas such as streams and marine shorelines; and/or landslide hazard areas that separates and protects critical areas from adverse impacts associated with adjacent land uses. 2.0 Methods The analysis of the resources on the subject property included preliminary office research and site - specific investigation. 2.1 Office Research Public resource documents have been reviewed to provide initial site information regarding hydrology, soils, and vegetation. Sources include: • Aerial photographs: USGS, 2003, Snohomish County, 2007. • Topographic maps: USGS Digital Raster Graphic Program, 1995 and Snohomish County Department of Information Services, GIS Division • Soil Survey of Snohomish County Area, Washington: USDA, Natural Resource Conservation Service (NRCS), 1999; Soil Survey Geographic Database for Snohomish County Area (wa661) • Watershed maps: Snohomish County Department of Information Services, GIS Division, 2003 • Water Type Classification Map: Snohomish County Department of Information Services, GIS Division, 2003 • NWI and Snohomish County Wetland Maps: U.S. Fish & Wildlife Service, 2003; National Wetlands Inventory (NWI) website, US Department of the Interior, Fish & Wildlife Service, St. Petersburg, FL; Snohomish County, 2003, Snohomish County Stream & Wetlands Atlas PWSWM Drainage Needs Report December 28, 2011 Page 5 of 16 Prepared by: Habitat Ecology and Design, Inc HEDI Job #: 11-0045 Trieu Delineation 2.2 Site Investigation Habitat Ecology and Design conducted field investigations on December 19, 2011, in accordance with the Washington State Wetlands Identification and Delineation Manual and the United States Corps of Engineers Wetlands Delineation Manual and the ACOE Interim Regional Supplement to the Corps of Engineers Wetland Delineation Manual: Western Mountains, Valleys, and Coast Region. In summary, data points were examined on site to assess presence or absence of hydrophytic vegetation, wetland hydrology, and hydric soils. Positive indicators for all three criteria are required for an area to be determined wetland. In addition, numerous soil auger holes were assessed throughout the subject property to determine wetland presence or absence. Habitat Ecology and Design rated wetlands using the revised Washington State Wetland Rating System for Western Washington as mandated under City of Edmonds Code. 2.3 Wetland Determination When all three parameters (vegetation, hydrology, and soils) were examined at an individual observation point, a wetland determination was made. A positive determination required that wetland indicators were present for all three parameters. If wetland criteria were not met for any one of the three parameters, the observation point was not considered to be within a wetland. 2.3.1 Vegetation Under normal circumstances the 1997 State Manual requires hydrophytic vegetation (vegetation that has adapted to life in saturated soil conditions) to be present for a location to be considered a wetland. For each soil log hole, dominant vegetation was determined by recording the percent cover of herbaceous vegetation within a 5-foot radius of the soil log hole and saplings, shrubs, and trees within a 30-foot radius of the log hole. Plants were divided into strata layers that included herb, sapling/shrub, and tree layers. Hydrophytic vegetation was identified according to Hitchcock and Cronquist (1978) and Cooke (1997) and considered to be present when greater than 50% of the dominant vegetation within a plant community had an indicator status of obligate wetland (OBL), facultative wetland (FACW), or facultative (FAC) according to the list of plant species that occur in wetlands (Reed, 1988 and 1993). 2.3.2 Hydrology In general, wetland hydrology is assumed to be present when a site is continuously inundated or saturated (within 12 inches of the surface) for greater than 12.5% of the growing season. An area that is inundated or saturated for 5% to 12.5% of the growing season may or may not possess wetland hydrology. Consistent with the 1997 State Manual, the presence of wetland hydrology was determined by evaluating direct and indirect indicators. Primary indicators include inundation, saturation in the upper 12 inches, water marks, drift lines, sediment deposits, and drainage patterns in wetlands. Secondary indicators include oxidized root channels in upper 12 inches, water stained leaves, local soil survey data, FAC-Neutral test. One primary indicator or two secondary indicators were required for a positive wetland hydrology result. 2.3.3 Soil The presence of hydric soils, which is necessary for a positive wetland determination, was investigated in accordance with the 1997 State Manual. Hydric soils are formed under conditions of saturation, flooding, or ponding long enough during the growing season to develop anaerobic conditions in the upper part of the soil profile (USDA NRCS, 2003). Hydric soil indicators, which December 28, 2011 Page 6 of 16 Prepared by: Habitat Ecology and Design, Inc HEDI Job #: 11-0045 Trieu Delineation include the presence of mottling, organic streaking, and sulfidic odors, must be present directly below the A Horizon, or 10 inches, whichever is shallower. Hydric indicators for non -sandy soils include organic soils (histosols), histic epipedons, sulfidic material, aquic or periaquic moisture regimes, reducing soil conditions, and soil color (gleyed soils, or non-gleyed soils with matrix chroma <_2 containing mottles or matrix chroma = 1 without mottles). Munsell Color Charts (Kollmorgen Corporation, 1988) were used to determine the matrix and mottle colors. Soil log holes were dug to a depth of at least 20 inches and soil texture was evaluated using a soil texture flow chart. 2.4 Off -site Evaluation of Critical Areas and Buffers A description and general characterization was completed for off -site critical areas and buffers adjacent to the project site. Drainage systems entering and leaving the site were identified and observed plant and wildlife species were recorded. 3.0 Results 3.1 Site Investigation Habitat Ecology and Design conducted field investigations on December 19, 2011, and found one wetland on the subject property. For the purposes of this report the wetland will be referred to as Wetland A (see Figure 5 for location). 3.1.1 Wetland A Wetland A is a seasonally inundated/saturated lacustrine:littoral emergent (LTEM) wetland that is located at the north property boundary of the site. The wetland is lacustrine, i.e. associated with a lake environment, with many areas of saturation and inundation observed throughout the unit. All three wetland indicators were observed throughout the wetland area during the field investigation. Many areas had 1-6" of ponded water with obligate wetland species (cattail, small fruited bulrush) present. Much of the wetland area is ponded during the wet season, with the margins seasonally saturated. No surface flow was observed through the wetland. The wetland appears to extend off -site to the east and west, although the precise location of the offsite boundaries was estimated visually and not marked. Primary and secondary indicators of hydrology were observed throughout much of the wetland, which included shallow inundation and saturation to the surface. Soil within the wetland was typified by an A horizon of mucky loam with a chroma 1 matrix to a depth of more than 14". Dominant plants within the wetland include cattail, small fruited bulrush, soft rush, Douglas spirea, , Scouler's willow, salmonberry, reed canary grass, and creeping buttercup. Based on the Washington State Wetland Rating System for Western Washington, the wetland meets the criteria for classification as a Category 3 Wetland. The wetland received a score of 16 for habitat functions, 14 for water quality functions and an overall score of 34. Therefore, it is Habitat Ecology and Design's assessment that this wetland requires a 50-foot buffer under ECDC 23.50.040(F)(c). Table 1: Wetland A Determination Summary December 28, 2011 Page 7 of 16 Prepared by: Habitat Ecology and Design, Inc HEDI Job #: 11-0045 Trieu Delineation M Hydrogeomorphic Classification I Lacustrine; littoral (near shore) Water Source/Outlet Lake Ballinger Hydrology Indicators Inundation and Saturated in the upper 12 inches. Typical Soil Profile Low chroma matrix with distinct redoximorphic features Wetland Rating Category 3 Wetland Buffer Requirements 50-foot standard buffer 3.2 Streams No channels, scour marks, or evidence of surface water runoff was observed on the subject property at the time of our site visit. 3.3 Off -site Evaluation of Critical Areas and Buffers Wetland A appears to continue off -site to the east and west, based on observed ponding, topography, and vegetation. Based on aerial photographs, the entire wetland unit appears to be less than 5,000 SF. The off -site portion of the wetland appears to consist primarily of mowed lawn vegetation, similar in character and composition to the conditions observed on -site. 3.4 Functions and Values Wetland A is a relatively disturbed lacustrine emergent wetland offering moderate functions for water quality improvement, and low functions for erosion and shoreline protection. Habitat functions are moderate; limited by the relative small size and isolation of the wetland and the lack of connective corridors to large, high quality wetland or upland habitats. 4.0 Proposed Development Activities Propose development activity on the subject property includes the reconstruction of the existing residence on the existing developed footprint, currently occupied by the structure and paved parking areas. The reconstructed residence is proposed to be constructed within currently developed areas; no native vegetation or wetland will be impacted by the proposed activity. The existing 50' buffer of Wetland A, as well as Wetland A itself are not proposed for any impacts. 4.1 Proposed Mitigation Since the proposed construction will not impact any wetlands, streams or their buffers, no mitigation measures should be required. 5.0 Conclusions One Category 3 wetland was identified on the subject property on December 19, 2011. The Category 3 wetlands extend off -site to the east and west. The onsite portions of this wetland is dominated by emergent vegetation, with small areas of scrub -shrub vegetation present. Offsite vegetation appears to be primarily emergent. Wetland A requires a 50' standard buffer, and is located more than 50' from any proposed activity. No streams were identified on the site. December 28, 2011 Page 8 of 16 Prepared by: Habitat Ecology and Design, Inc HEDI Job #: 11-0045 Trieu Delineation This stream and wetland delineation should be considered subject to change until reviewed and approved by the appropriate regulatory agencies with jurisdiction. The attached drawing does not represent a survey and should be considered for conceptual feasibility purposes only. 6.0 Disclaimer Habitat Ecology and Design, Inc. has prepared this Wetland Delineation Report for Frank Trieu. The information contained herein is, to our knowledge, correct and accurate. It should be recognized that the establishment of stream and wetland boundaries is an inexact science. Streams are subject to weather patterns, in addition to upstream and downstream activities. Wetlands are, by definition, transition areas, and wetland boundaries often change with time. The presence of wetland indicators may also vary depending on the time of year. Additionally, individual professionals may disagree on the precise location of wetland boundaries or the functions and values of a wetland. All stream and wetland boundaries, classifications, and buffer widths should be considered subject to change until reviewed and approved by the appropriate regulatory agencies with jurisdiction. We recommend obtaining jurisdictional approval before completing final site plans and/or beginning construction activities. We are not responsible for the accuracy of information provided by others. Within the limitations of schedule, budget, and scope -of -work, we warrant that this study was conducted in accordance with generally accepted environmental science practices, including the technical guidelines and criteria in effect at the time of this study. The results and conclusions of this report represent the authors' best professional judgment based upon information provided by the project proponent and information obtained during the course of this study. No other warranty, expressed or implied, is made. December 28, 2011 Page 9 of 16 Prepared by: Habitat Ecology and Design, Inc HEDI Job #: 11-0045 Trieu Delineation 7.0 References Cooke, S.S. 1997. Field Guide to the Common Wetland Plants of Western Washington and Northwestern Oregon. Seattle, WA, Seattle Audubon Society. Cooke, S.S. 2000. Wetland and buffer functions, a semi -quantitative assessment methodology. Cooke Scientific Services, Inc., Seattle, Washington. Cowardin, L.M., V. Carter, F.C. Golet, and E.T. LaRoe. 1979. Classification of Wetlands and Deepwater Habitats of the United States. FWS/OBS-79/31. Office of Biological Services, Fish and Wildlife Service, US Department of the Interior, Washington DC. Environmental Laboratory. 1987. Corps of Engineers Wetlands Delineation Manual. Technical Report Y-87-1. Corps of Engineers, Waterways Experiment Station, Vicksburg, MS. Federal Interagency Committee for Wetland Delineation. 1989. Federal Manual for Identifying and Delineating Jurisdictional Wetlands. U.S. Army Corps of Engineers, U.S. Environmental Protection Agency, U.S. Fish and Wildlife Services, and USDA Soil Conservation Service, Washington, D.C. Cooperative technique publication. Hitchcock, C.L. and A. Cronquist. 1976. Flora of the Pacific Northwest. Seattle, WA, University of Washington Press. Kollmorgen Corporation. 1988. Munsell soil color charts. Baltimore, Maryland. Reed, P.B., Jr. 1993. Supplement to National List of Plant Species that Occur in Wetlands: Northwest (Region 9). U.S. F.W.S. Biol. Rep. Reed, P.B., Jr. 1988. National list of plant species that occur in wetlands: Northwest (Region 9). U.S. Fish Wildlife Service Biol. Rep. 88(26.9). Washington Department of Ecology. 1997. Washington State Wetlands Identification and Delineation Manual. Publication 96-94. Washington State Department of Ecology. Olympia, WA. December 28, 2011 Page 10 of 16 Prepared by: Habitat Ecology and Design, Inc HEDI Job k: 11-0045 Trieu Delineation Appendix A: Maps and Figures Location Map Trieu Delineation H a tyOOtogY 0 500 1,000 2,000 Feet Vicinity Map Image courtesy of Snohomish County, 2006 Figure l: Site Location March 25, 2011 Page 11 of 16 Prepared by: Habitat Ecology and Design, Inc HEDI Job R: 10-0008 Trieu Delineation Aerial Photograph Trieu Delineation xti Ecology 0 25 50 100gi D Feet Site Aerial �` J Image courtesy of Snohomish County, 2006 Figure 2: Aerial Photograph March 25, 2011 Page 12 of 16 Prepared by: Habitat Ecology and Design, Inc HEDI Job #: 10-0008 0 Trieu Delineation Mapped Wetlands and Streams Trieu Delineation m14 - bi"Ecology 0 500 1,000 2,000 Feet Mapped Wetlands & Hydrology Image courtesy of Snohomish County, 2006 Figure 3: Wetlands & Hydrology Map March 25, 2011 Page 13 of 16 Prepared by: Habitat Ecology and Design, Inc HEDI Job #: 10-0008 Trieu Delineation Soil and Topographic Map . fT Legend` i P Sao ® Subject Property • 5 Contours ® SnoSoil3 (2) Aldervvood gravely sandy loam, 8 to 1596 slo +. (J2) McKenna gravely 31111 oam, 0 m 8%slopes ;� . Ip 410 321 McKenna revelly, Ot wam, OEM �`- • � _ (1) Aldervrood.gravely sandy loam, 2 to 8% slo'pes 4j �� m 0 100 200 400 eet Evans Delineation Ha b t c6logy & Mapped Soils & Topography esiga, Inc. 3: Image courtesy of Snohomish County, 2006 "fit °��•- I� Figure 4: Soils & Topography Map March 25, 2011 Page 14 of 16 Prepared by: Habitat Ecology and Design, Inc HEDI Job #: 10-0008 Trieu Delineation Critical Areas Delineation Sketch �tlen A vs � �. I Categ ry�3 v'', 1 '-:• a 4 y� 1 Flag AS 1 ' �a. sL2 of . Flag Al !' 0 15 50 1,00 a Trieu Delineation Delineation Sketch Image courtesy of Snohomish County, 2006 Figure 5: Critical Areas Sketch March 25, 2011 Prepared by: Habitat Ecology and Design, Inc Legend F—ISubject Property s. Wetland A 50' Wetland A Buffer t Wetland Flag Soil Data Point H bit" t Ecology be y" Page 15 of 16 HEDI Job #: 10-0008 T_ �� 1�1 aXt R 1 % •�- - _��°t Wetland name or number: Wetland A WETLAND RATING FORM — WESTERN WASHINGTON Version 2 — Updated July 2006 to increase accuracy and reproducibility among users Updated Oct. 2008 with the new WDFW definitions for priority habitats Name of wetland (if known): Trieu/Ballinger Wetland A Date of site visit: 12/19/11 Rated by: K. Karlson Trained by Ecology? Yes X No Date of training: October 2005 SEC: 27 TWNSHP: 4 RNGE: 32 Is S/T/R in Appendix D? Yes No: X Map of wetland unit: Figure: 5 Estimated size: <5.000 SF SUMMARY OF RATING Category based on FUNCTIONS provided by wetland: I II CIII Category I = Score > 70 Category II = Score 51 - 69 Category III = Score 30 — 50 Category IV = Score < 30 Score for Water Quality Functions Category based on SPECIAL CHARACTERISTCS of Wetland Score for Hydrologic Functions Score for Habitat Functions TOTAL Score for Functions 14 4 16 34 I II Does not apply: X Filial Category (choose the "highest" category from above") III Summary of basic information about the wetland unit. `Estuarine Natural Heritage Wetland Bo Mature Forest Old Growth Forest Coastal Lagoon Interdunal None of the above De ressional Riverine Lake -fringe X Slope Flats Freshwater Tidal Check if unit has multiple HGM classes present Does the wetland being rated meet any of the criteria below? If you answer YES to any of the questions below you will ne.ed to nrotect the wetland according to the regulations regarding the special characteristics found in the wetland. R SP l . Has the wetland unit been documented as a habitat for any Federally listed Threatened or X Endangered animal or plant species (TIE species)? For the purposes of this rating system, "documented" means the wetland is on the appropriate state or federal database. SP2. Has the wetland unit been documented as habitat for any State listed Threatened or X Endangered animal species? For the purposes of this rating system, "documented" means the wetland is on the appropriate state database. Note: Wetlands with State listed plant species are categorized as Category 1 Natural Heritage Wetlands (see p. 19 of data form). SP3. Does the wetland unit contain individuals of Priority species listed by the WDFW for the state? X SP4. Does the wetland unit have a local significance in addition to its functions? For example, the X wetland has been identified in the Shoreline Master Program, the Critical Areas Ordinance, or in a local management plan as having special significance. To complete the next part of the data sheet you will need to determine the Hydroeg omorphic Class of the wetland beingrated. ated. The hydrogeornotphic classification groups wetlands in to tttose that function in similar ways. This simplifies the questions needed to answer how well the wetland fiutctions. The Hydrogeomorphic Class of a wetland can be determined using the key below. See p. 24 for more detailed instructions on classifying wetlands. Wetland Rating Form — Western Washington, Version 2 (7/06), updated with new WDFW definitions Oct. 2008 Page I of 8 Wetland name or number: Wetland A Classification of Vegetated Wetlands for Western Washington evels in the entire unit usually controlled by tides (i.e. except during floods)? NO — o t YES — the wetland class is Tidal Fringe If yes, is the salinity of the water during periods of annual low flow below 0.5 ppt (parts per thousand)? YES — Freshwater Tidal Fringe NO — Saltwater Tidal Fringe (Estuarine) If your wetland can be classified as a Freshwater Tidal Fringe use the forms for Riverine wetlands. If it is a Saltwater Tidal Fringe it is rated as an Estuarine wetland. Wetlands that were call estuarine in the first and second editions of the rating system are called Salt Water Tidal Fringe in the Hydrogeomorphic Classification. Estuarine wetlands were categorized separately in the earlier editions, and this separation is being kept in this revision. To maintain consistency between editions, the term "Estuarine" wetland is kept. Please note, however, that the characteristics that define Category I and H estuarine wetlands have changed (see p. ). 2. The entire wetland unit is flat and precipitation is only source (>90%) of water to it. Groundwater and surface water runoff are NOT so s of water to unit. NO — go to 3 YES — The wetland class is Flats If your wetlan as a "Flats" wetland, use the form for Depressional wetlands. 3. Does the entire wetland meet both of the following criteria? The vegetated part of the wetland is on the shores of a body of permanent open water (without any vegetation on the surface) where at least 20 acres At least 30% of the open war s eeper than 6.6 (2 m)? NO — go to 4 ES — The wetland class is Lake -fringe (Lacustrine Frin 4. Does the entire wetland meet all of the following criteria? The wetland is on a slope (slope can be very gradual). The water flows through the wetland in one direction (unidirectional) and usually comes from seeps. It may flow subsurface, as sheetflow, or in a swale without distinct banks. The water leaves the wetland without being impounded? NOTE: Surface water does not pond in these types of wetlands except occasionally in very small and shallow depressions or behind hummocks (depressions are usually <3 ft diameter and less than I foot deep). NO — go to 5 YES — The wetland class is Slope 5. Does the entire wetland meet all of the following criteria? The unit is in a valley or stream channel where it gets inundated by overbank flooding from that stream or river. The overbank flooding occurs at least once every two years. NOTE: The riverine unit can contain depressions that are filled with water when the river is not flooding.. NO — go to 6 YES — The wetland class is Riverine 6. Is the entire wetland unit in a topographic depression in which water ponds, or is saturated to the surface, at some time of the year. This means that any outlet, if present is higher than the interior of the wetland. NO — go to 7 YES — The wetland class is Depressional 7. Is the entire wetland located in a very flat area with no obvious depression and no overbank flooding. The unit does not pond surface water more than a few inches. The unit seems to be maintained by high groundwater in the area. The wetland may be ditched, but has no obvious natural outlet. No — go to 8 YES — The wetland class is Depressional 8. Your wetland unit seems to be difficult to classify and probably contains several different HGM classes. For example, seeps at the base of a slope may grade into a riverine floodplain, or a small stream within a depressional wetland has a zone of flooding along its sides. GO BACK AND IDENTIFY WHICH OF THE HYDROLOGIC REGIMES DESCRIBED IN QUESTIONS 1-7 APPLY TO DIFFERENT AREAS IN THE UNIT (make a rough sketch to help you decide). Use the following table to identify the appropriate class to use for the rating system if you have several HGM classes present within your wetland. NOTE: Use this table only if the class that is recommended in the second column represents 10% or more of the total area of the wetland unit being rated. If the area of the class listed in column 2 is less than 10% of the unit, classify the wetland using the class that represents more than 90% of the total area. [ H'.GM C««.lasses within th_e wetland -un'i� b�e�n `rated ,:" 6 �. �:a,a : HGM;GIasso Usesi-nyR+ ati Slope + Riverine Riverine Slope + Depressional De ressional Slope + Lake -fringe Lake -fringe Depressional + Riverine along stream within boundary Depression I Depressional + Lake -fringe Depressional Salt Water Tidal Fringe and any other class of freshwater wetland Treat as ESTUARINE under wetlands with special characteristics If you are unable still to determine which of the above criteria apply to your wetland, or you have more than l Hum classes within a wetland boundary, classify the wetland as Depressional for the rating. Wetland Rating Form — Western Washington, Version 2 (7/06), updated with new WDFW definitions Oct. 2008 Page 2 of 8 R Wetland "name or number: Wetland A Does the wetland unit have the potential to improve water quality? (see p.59) P b L 1 L 1.1 Average width of vegetation along the lakeshore (use polygons of Cowardin classes): Figure 5 • Vegetation is more than 33 ft. (10m) wide........................................................................... points = 6 • Vegetation is more than 16 ft.(5m) wide and < 33 ft............................................................ points = 3 1 • Vegetation is more than 6 ft. (2m) wide and < 16 ft.................................................... .......points = • Vegetation is less than 6 ft. wide .......................... ....... .................... I............... ' - Ma of Cowardin classes with widths marked L 1.2 Characteristics of the vegetation in the wetland: Choose the appropriate description that results in the highest Figure 5 points, and do not include any open water in your estimate of coverage. The herbaceous plants can be either the dominant form or as an understory in a shrub or forest community. These are not Cowardin classes. Area of Cover is total cover in the unit, but it can be in patches. NOTE: Herbaceous does not include aquatic bed. • Cover of herbaceous plants is > 90% of the vegetated area ................................................ => 6 • Cover of herbaceous plants is > 2/3 of the vegetated area ..................................................... points = 4 • Cover of herbaceous plants is > 1/3 of the vegetated area ..................................................... points = 3 • Other vegetation that is not aquatic bed or herbaceous covers > 2/3 of the unit .................... points = 3 • Other vegetation that is not aquatic bed in > 1/3 vegetated area ........................................... points = I • Aquatic bed cover and open water > 2/3 of the unit.............................................................. points = 0 Map with polygons of different vegetation t es Add the points in the boxes above 7 L 2 Does the wetland have the opportunity, to improve water quality? (see p.61) Answer YES if you know or believe there are pollutants in the lake water, or polluted surface water flowing through the unit to the lake. Note which of the following conditions provide the sources of pollutants. A unit may have pollutants coming from several sources, but any single source would qualify as opportunity. Wetland is along the shores of a lake or reservoir that does not meet water quality standards Grazing in the wetland or within 150 ft Polluted water discharges to wetland along upland edge Tit —al or -urban areas are w' Parks with grassy areas that are maintained, ballfields, golf courses (all within 150 ft. of lake shore) Multiplier Power boats with gasoline or diesel engines use the lake Other 2 YES multiplier is 2 NO multiplier is I ♦ TOTAL — Water Quality Functions Multiply the score from L1 by 1-2; then add score to table on p. 1 14 4 FC1NC IONS —Indicators that wetland functions to reduce shoreline erosion , _ =• ;_+ YD O• LOG C L 3 Does the wetland have the potential to reduce shoreline erosion? .(sjep..62) L 3 Average width and characteristics of vegetation along the lakeshore (do not include aquatic bed). - (choose the highest scoring description that matches conditions in the wetland) Figure 5 • 3/4 of distance is shrubs or forest at least 33 ft. (10m) wide ................................................. points = 6 • 3/4 of distance is shrubs or forest at least 6 ft. (2m) wide ..................................................... points = 4 • 1/4 of distance is shrubs or forest at least 33 ft. (10m) wide ................................................. i is = 4 2 • Vegetation is at least 6 ft. (2m) wide (any type except aquatic bed) ............................. ....... points = • Vegetation is less than 6 ft. (2m) wide (any type except aquatic bed) ................................... — Aerial photo or map with Cowardin ve etation classes Record the points in the boxes above 2 L 4 Does the wetland have the opportunity to reduce erosion? (seep. 64) Are there features along the shore that will be impacted if the shoreline erodes? Note which of the following conditions apply. There are human structures and activities along the upland edge of the wetland (buildings, fields) that can be damaged by erosion. Multiplier There are undisturbed natural resources along the upland edge of the wetland (e.g. mature forests, other wetlands) that can be damaged by shoreline erosion. 2 Other S multi lier is NO multiplier is 1 ♦ TOTAL —Hydrologic Functions Multiply the score from L3 by 1-4; then add score to table on p. 1 4 Comments: Wetland Rating Form — Western Washington, Version 2 (7/06), updated with new WDFW definitions Oct. 2008 Page 3 of 8 Wetland"name or number: Wetland A A O nfflat a r3 an uncti to • rov • e important habitat. p box H 1 Does the wetland have the aotential to provide habitat for many species? H 1.1 Vegetation structure (see P. 72): Figure 5 Check the types of vegetation classes present (as defined by Cowardin) — Size threshold for each class is 114 acre or more than 10% of the area if unit is smaller than 2.5 acres. X Aquatic Bed X Emergent plants 2 X Scrub/shrub (areas where shrubs have > 30% cover) Forested (areas where trees have > 30% cover) If the unit has a forested class check if: The forested class has 3 out of 5 strata (canopy, sub -canopy, shrubs, herbaceous, moss/ground- cover) that each cover 20% within the forested polygon. Add the number of vegetation types that qualify. If you have: M ac es 4 structures or more....... points = 4 uctures................... of is — 2 structures .................... points = 1 1 structure .................... points = 0 H 1.2 Hydroperiods (see p.73): Figure 5 Check the types of water regimes (hydroperiods) present within the wetland. The water regime has to cover more than 10% of the wetland or 114 acre to count (see text for descriptions of hydroperiods). X Permanently flooded or inundated 4 or more types present oints = 3 X Seasonally flooded or inundated more types present ...... potn s = 2 Occasionally flooded or inundated ftnT = X Saturated only I type present ....................points = 0 Permanently flowing stream or river in, or adjacent to, the wetland Seasonally flowing stream in, or adjacent to, the wetland Lake -fringe wetland ................. = 2 points Freshwater tidal wetland......... = 2 points Map of hydroperiods H 1.3 Richness of Plant Species (see p. 75): Count the number of plant species in the wetland that cover at least 10 ftZ (different patches of the same species can be combined to meet the size threshold) You do not have to name the species. Do not include Eurasian Milfoil, reed canarygrass, purple loosestrife, Canadian Thistle. If you counted: > 19 species ................... 5 — 19 species .................. otnts — 1 List species below if you want to: < 5 species ........................ points = 0 H 1.4 Interspersion of Habitats (see p. 76): Decided from the diagrams below whether interspersion between Cowardin vegetation (described in H 1. 1), or the classes and unvegetated areas (can include open w t udflats) is high, medium, low, or none. s Note: If you have 4 or more classes or 3 vegetation classes and Figure 5 open water, the rating is None = 0 points Low = 1 point Moderate = 2 po always "high". 2 7 Use map of Cowardin classes [riparian braided channels] H 1.5 Special Habitat Features (see p. 77): Check the habitat.features that are present in the wetland. The number of checks is the number of points you put into the next column. Large, downed, woody debris within the wetland (> 4 in. diameter and 6 ft. long) Standing snags (diameter at the bottom > 4 inches) in the wetland Undercut banks are present for at least 6.6 ft. (2m) and/or overhanging vegetation extends at least 3.3 ft. (Im) over a stream (or ditch) in, or contiguous with the unit, for at least 33 ft. (10m) 0 Stable steep banks of fine material that might be used by beaver or muskrat for denning (> 30 degree slope) OR signs of recent beaver activity are present (cut shrubs or trees that have not yet turned grey/brown) _ At least 1/4 acre of thin -stemmed persistent vegetation or woody branches are present in areas that are permanently or seasonally inundated (structures for egg -laying by amphibians) Invasive plants cover less than 25% of the wetland area in each stratum of plants NOTE: The 20% stated in early printings of the manual on page 78 is an error. H 1 TOTAL Score — potential for providing habitat Add the points in the column above 7 Wetland Rating Form — Western Washington, Version 2 (7/06), updated with new WDFW definitions Oct. 2008 Page 4 of 8 i, • Wetland name or number: Wetland A H 2 Does the wetland have the opportunity to provide habitat for many species? o t scor e H 2.1 Buffers (see P. 80): Figure 5 Choose the description that best represents condition of buffer of wetland unit. The highest scoring criterion that applies to the wetland is to be used in the rating. See text for definition of "undisturbed". 100m (330 ft) of relatively undisturbed vegetated areas, rocky areas, or open water > 95% of circumference. No structures are within the undisturbed part of buffer (relatively undisturbed also means no grazing, no landscaping, no daily human use) ............. points = 5 3 100m (330 ft) of relatively undisturbed vegetated areas, rocky areas, or open water > 50% circumference.................................................................................................... points = 4 50m (170 ft) of relatively undisturbed vegetated areas, rocky areas, or open water > 95% circumference.................................................................................................... points = 4 100m (330 ft) of relatively undisturbed vegetated areas, rocky areas, or open water > 25% circumference........................................................................................... p ' t = 50m (170 ft) of relatively undisturbed vegetated areas, rocky areas, or open water for > 50% circumference.............................................................................................. points = 3 If buffer does not meet any of the criteria above: No paved areas (except paved trails) or buildings within 25m (80 ft) of wetland > 95% circumference. Light to moderate grazing or lawns are OK .................................. points = 2 No paved areas of buildings within 50m of wetland for > 50% circumference. Light to moderate grazing or lawns are OK................................................................... points = 2 _ Heavy grazing in buffer................................................................................................ points = 1 _ Vegetated buffers are < 2m wide (6.6 ft) for more than 95% circumference (e.g. tilled fields, paving, basalt bedrock extend to edge of wetland) ............................. points = 0 Buffer does not meet any of the criteria above.............................................................. points = 1 Arial photo showing buffers H 2.2 Corridors and Connections (seep. 81) H 2.2.1 Is the wetland part of a relatively undisturbed and unbroken vegetated corridor (either riparian or upland) that is at least 150 ft. wide, has at least a 30% cover of shrubs, forest or native undisturbed prairie, that connects to estuaries, other wetlands or undisturbed uplands that are at least 250 acres in size? (Dams in riparian corridors, hea oads, paved roads, are considered breaks in the corridor). YES = 4 points (go to H 2.3) NO = go to H 2.2.2 H. 2.2.2 Is the wetland part of a relatively undisturbed and unbroken v corridor (either riparian 1 or upland) that is at least 50 ft. wide, has at least 30% cover of shrubs or forest, and connects to estuaries, other wetlands or undisturbed uplands that are 'n size? OR a Lake - fringe wetland, if it does not have an undisturbe orridor as in the question a ve? YES = 2 points (go to H 2.3) NO = go to H 2.2.3 H. 2.2.3 Is the wetland: • Within 5 mi (8km) of a brackish or salt water estuary OR • Within 3 miles of a large field or pasture (> 40 acres) OR YES =�points • Within 1 mile of a lake greater than 20 acres? = Comments: Wetland Rating Form — Western Washington, Version 2 (7/06), updated with new WDFW definitions Oct. 2008 Page 5 of 8 M 6, Wetland tiame or. number: Wetland A H 2.3 Near or adjacent to other priority habitats listed by WDFW (see p. 82): (see new and complete descriptions of WDFW priority habitats, and the counties in which they can be found, in the PHS report http://wdfw.wa.Qov/hab/phslist.htm ) Which of the following priority habitats are within 330 ft. (loom) of the wetland unit? NOTE: the connections do not have to be relatively undisturbed. _ Aspen Stands: Pure or mixed stands of aspen greater than 0.4 ha (I acre). Biodiversity Areas and Corridors: Areas of habitat that are relatively important to various species of native fish and wildlife (full descriptions in WDFW PHS report p. 152). Herbaceous Balds: Variable size patches of grass and forbs on shallow soils over bedrock. Old-growth/Mature forests: (Old -growth west of Cascade crest) Stands of at least 2 tree species, forming a multi -layered canopy with occasional small openings; with at least 20 trees/ha (8 trees/acre) > 81 cm (32 in) dbh or > 200 years of age. (Mature forests) Stands with average diameters exceeding 53 cm (21 in) dbh; crown cover may be less that 100%; decay, decadence, numbers of snags, and quantity of large downed material is generally less than that found in old -growth; 80 - 200 years old west of the Cascade crest. Oregon white Oak: Woodlands Stands of pure oak or oak/conifer associations where canopy coverage of the oak component is important (full descriptions in WDFW PHS report p. 158). Riparian: The area adjacent to aquatic systems with flowing water that contains elements of both aquatic and terrestrial ecosystems which mutually influence each other. Westside Prairies: Herbaceous, non -forested plant communities that can either take the form of a dry prairie or a wet prairie (full descriptions in WDFW PHS report p. 161). 0 Instream: The combination of physical, biological, and chemical processes and conditions that interact to provide functional life history requirements for instream fish and wildlife resources. _ Nearshore: Relatively undisturbed nearshore habitats. These include Coastal Nearshore, Open Coast Nearshore, and Puget Sound Nearshore. (full descriptions of habitats and the definition of relatively undisturbed are in WDFW report: pp. 167-169 and glossary in Appendix A). Caves: A naturally occurring cavity, recess, void, or system of interconnected passages under the earth in soils, rock, ice, or other geological formations and is large enough to contain a human. _ Cliffs: Greater than 7.6 m (25 ft) high and occurring below 5000 ft. Talus: Homogenous areas of rock rubble ranging in average size 0.15 - 2.0 m (0.5 - 6.5 ft), composed of basalt, andesite, and/or sedimentary rock, including riprap slides and mine tailings. May be associated with cliffs. Snags and Logs: Trees are considered snags if they are dead or dying and exhibit sufficient decay characteristics to enable cavity excavation/use by wildlife. Priority snags have a diameter at breast height of > 51 cm (20 in) in western Washington and are > 2 in (6.5 ft) in height. Priority logs are > 30 cm (12 in) in diameter at the largest end, and > 6 in (20 ft) long. If wetland has 3 or more priority habitats = 4 points If wetland has 2 priority habitats = 3 points If wetland has 1 priority habitat =1 point No habitats = 0 points Note: All vegetated wetlands are by definition a priority habitat but are not included in this list. Nearby wetlands are addressed in question H 2.4) H 2.4 Wetland Landscape: Choose the one description of the landscape around the wetland that best fits (see p. 84) • There are at least 3 other wetlands within 1/2 mile, and the connections between them are relatively undisturbed (light grazing between wetlands OK, as is lake shore with some boati but connections should NOT be bisected by paved roads, fill, fields, or other development... oints = • The wetland is Lake -fringe on a lake with little disturbance and there are 3 other lake -fringe wetlandswithin 1/2 mile.....................................................................................................points = 5 5 • There are at least 3 other wetlands within 1/2 mile, BUT the connections between them are disturbed.............................................................................................................................points = 3 • The wetland fringe on a lake with disturbance and there are 3 other lake -fringe wetlands within1/2 mile....................................................................................................................points = 3 • There is at least 1 wetland within 1/2 mile...........................................................................points = 2 • There are no wetlands within 1/2 mile.................................................................................. points = 0 H 2 TOTAL Score — opportunity for providing habitat Add the scores from H2.1, H2.2, H2.3, H2.4 9 7_ i TOTAL for H I from page 8 ♦ Total Score for Habitat Functions Add the points for H 1 and H 2; then record the result on p. 1 16 Comments: Wetland Rating Form — Western Washington, Version 2 (7/06), updated with new WDFW definitions Oct. 2008 Page 6 of 8 Wetland name or number: Wetland A CATEGORIZATION BASED ON SPECIAL CHARACTERISTICS Please determine if the wetland meets the attributes described below and circle the appropriate answers and Category. WeWan Type — G�heck off any rite -rig tha a• p y to -he etland. ' �l th at gory when th appropria Estuarine wetlands? (see p.86) C1 Does the wetland unit meet the following criteria for Estuarine wetlands? The dominant water regime is tidal, Vegetated, and _ With a salinity greater than 0.5 ppt. YES = Go to SC 1.1 NO SC 1.1 Is the wetland unit within a National Wildlife Re e, National Parl ' ational Estuary Reserve, Natural Area Preserve, State Park or Educational, Environmenta , tentific Reserve designated under WAC Cat. 1 332-30-151? YES = Category I NO = go to SC 1.2 SC 1.2 Is the wetland at least I acre in size and meets at least two of the following conditions? YES = Category I NO = Category II Cat. I The wetland is relatively undisturbed (has no diking, ditching, filling, cultivation, grazing, and has less than 10% cover of non-native plant species. If the non-native Spartina spp,. are only species Cat. II that cover more than 10% of the wetland, then the wetland should be given a dual rating (I/II). The area of Spartina would be rated a Category II while the relatively undisturbed upper marsh with native species would be a Category 1. Do not, however, exclude the area of Spartina in determining the size threshold of I acre. Dual _ At least 3/4 of the landward edge of the wetland has a 100 ft. buffer of shrub, forest, or un-grazed Rating or un-mowed grassland I/II The wetland has at least 2 of the following features: tidal channels, depressions with open water, or contiguous freshwater wetlands. C2 Natural Heritage Wetlands (seep. 87) Natural Heritage wetlands have been identified by the Washington Natural Heritage Program/DNR as either high quality undisturbed wetlands or wetlands that support state Threatened, Endangered, or Sensitive plant species. SC 2.1 Is the wetland being rated in a Section/Township/Range that contains a natural heritage wetland? (This question is used to screen out , ;. c h ore you need to contact WNHP/DNR.) S/T/R information fr Appendix D or accessed from WNHP/DNR YES P/DNR (see p. 79) and go to SC 2.2 NO SC 2.2 Has DNR identified the wetland as a high quality undisturbed wetland or as a site with state or endangered plant species? Cat I YES = Category I NO not a Heritage Wetland C3 Bogs (seep. 87) Does the wetland (or any part of the unit) meet both the criteria for soils and vegetation in bogs? Use the key below to identify if the wetland is a bog. If you answer yes you will still need to rate the wetland based on its function. I. Does the unit have organic soil horizons (i.e. layers of organic soil), either peats or mucks, that compose 16 inches or more of the first 32 inches of soil prof' a field key to identify organic soils)? YES = go to question 3 NO = go to question 2 2. Does the wetland have organic soils, either peats or muc t are less than 16 inc t ep over bedrock, or an impermeable hardpan such as clay or volcan' a are oa in ' ' r pond? YES = go to question 3 NO = is not a bog for purpose of rating 3. Does the unit have more than 70% cover of mosses a and level, AND other plants, if present consist of the "bog" species listed in Table 3 as a significant c ore than 30% of the total shrub and herbaceous cover consists of species in Table 3)? YES = Is a bog for purpose of rating NO = go to question 4 NOTE: If you are uncertain about the extent of mosses in the understory you may substitute that criterion by measuring the pH of the water that seeps into a hole dug at least 16" deep. If the pH is less than 5.0 and the "bog" plant species in Table 3 are present, the wetland is a bog. 4. Is the unit forested (> 30% cover) with sitka spruce, subalpine fir, western red cedar, western hemlock, lodgepole pine, quaking aspen, Englemann's spruce, or western white pine. WITH any of the species (or combination of species) on the bog species plant list in Table 3 as a significant component of the ground cover (> 30% coverage of the total shrub/herbaceous cover)? Cat. I YES = Category I NO = Is not a bog for purpose of rating Wetland Rating Form — Western Washington, Version 2 (7/06), updated with new WDFW definitions Oct. 2008 Page 7 of 8 I. 'Wetland name or number: Wetland A C4 Forested Wetlands (see p. 90) Does the wetland have at least 1 acre of forest that meet one of these criteria for the Department of Fish and Wildlife's forests as priority habitats? If you answer yes you will still need to rate the wetland based on its function. _ Old -growth forests: (west of Cascade Crest) Stands of at least two three species forming a multi -layered canopy with occasional small openings; with at least 8 trees/acre (20 trees/hectare) that are at least 200 years of age OR have a diameter at breast height (dbh) of 32 inches (81 cm or more). NOTE: The criterion for dbh is based on measurements for upland forests. Two -hundred year old trees in wetlands will often have a smaller dbh because their growth rates are often slower. The DFW criterion is and "OR" so old -growth forests do not necessarily have to have trees of this diameter. Mature forests: (west of the Cascade Crest) Stands where the largest trees are 80 — 200 years old OR have an average diameters (dbh) exceeding 21 inches (53 cm); crown cover may be less than 100%; decay, decadence, numbers of snags, a Prial 's enerally less than that found in old -grown Cat. I YES = Category I O = not a forested wetland with special characterise' C5 Wetlands in Coastal Lagoons (seep. 91) Does the wetland meet all of the following criteria of a wetland in a coastal lagoon? The wetland lies in a depression adjacent to marine waters that is wholly or partially separated from marine waters by sandbanks, gravel banks, shingle, or, less frequently, rocks. The lagoon in which the wetland is located contains surface water that is saline or brackish (> 0.5 ppt) during most of the year in at least a portion of the lagoon (needs to be measured near the bottom.) YES = Go to SC 5.1 not a wetland in a coast t SC 5.1 Does the wetland meet all of the following three conditions? The wetland is relatively undisturbed (has no diking, ditching, filling, cultivation, grazing) and has less than 20% cover of invasive plant species (see list of invasive species on p. 74). _ At least 3/4 of the landward edge of the wetland has a 100 ft. buffer of shrub, forest, or un-grazed or un-mowed grassland. Cat. I The wetland is larger than 1/10 acre (4350 square ft.) YES = Category I NO = Category II Cat. II C6 Interdunal Wetlands (see p. 93) Is the wetland west of the 1889 line (also called the Western Boundary of Upland Ownership or WBUO)? YES = Go to SC 6.1 O not an interdunal wetland for ratin If you answer yes you will still need to rate t e we an ase on t s unctions. In practical terms that means the following geographic areas: • Long Beach Peninsula -- lands west of SR 103 • Gray] and -Westport -- lands west of SR 105 • Ocean Shores-Copalis — lands west of SR 115 and SR 109 SC 6.1 Is the wetland one acre or larger, or is it in a mosaic of wetlands that is one acre or larger? YES = Category I1 NO = go to SC 6.2 Cat. II SC 6.2 Is the wetland between 0.1 and 1 acre, or is it in a mosaic of wetlands that is between 0.1 and 1 acre? YES = Category III Cat. III Category of wetland based on Special Characteristics ♦ Choose the "highest" rating if wetland falls into several categories, and record on p. 1. If you answered NO for all types enter "Not Applicable" on p. 1 Comments: Wetland Rating Form — Western Washington, Version 2 (7/06), updated with new WDFW definitions Oct. 2008 Page 8 of 8 J.C. Mc DONNELL ENGINEERING, P.C. Consulting Civil Engineers 6608 — 216 Street SW; #306 Mountlake Terrace, WA. 98043 STORM DRAINAGE STUDY For HOA TRIEU SFR Located at 7109 Lake Ballinger Way n, Edmonds, WA. TAX ID.: 00488800800700 �O DEVELOPER: Mr. Hoa Trieu 7109 Lake Ballinger Way Edmonds, WA. 98026 Issue Date: January 20, 2012 Revision Date: February 22, 2012 2°d Revision Date: May 4, 2012 PREPARED BY: J. C. McDonnell, MS, PE Surveyor of Record: Green Land Surveying Edmonds & Soap Lake Tel: (206) 498-0979 RESUB, MAY - 8 2012 RMLSING DcPARTME 1 CITY OF r-DIM DS CITY COPY J.C. Mc DONNELL ENGINEERING, P.C. Consulting Civil Engineers 6608 — 216 h Street SW; #306 Mountlake Terrace, WA. 98043 STORM DRAINAGE STUDY For HOA TRIEU SFR Located at 7109 Lake Ballinger Way Edmonds, WA. TAX ID.: 00488800800700 DEVELOPER: Mr. Hoa Trieu 7109 Lake Ballinger Way Edmonds, WA. 98026 Issue Date: January 20, 2012 Revision Date: February 22, 2012 2"d Revision Date: May 4, 2012 PREPARED BY: J. C. McDonnell, MS, PE Surveyor of Record: Green Land Surveying Edmonds & Soap Lake Tel: (206) 498-0979 (OFF) 425 744-0916 (CELL) 425 359-2717 (FA)Q 425 744-0946 ' Trieu SFR Drainage Report ' 5/04/2012 REV.3 tEXECUTIVE SUMMARY ' The proposed project is a developed lot located at at 7109-Lake Ballinger Way (SR104) at south end of Lake Ballinger in Edmonds, WA. 98020. The Legal Description places the property in Section 05, Township 27N, Range 03E, WM. The existing site is fully ' developed residential lot sloping from Lake Ballinger Way (NE 2051h Street). Sewer, water, telephone and power utilities are active to the existing house (constructed in 1946). A municipal sewer main crosses the property between the house and the Lake. LEGAL DESCRIPTION: ASSESSOR'S PARCEL #00488800800700 ' PER DEED OF TRUST A.F.#200207120622 LOT 7, BLOCK 8, LAKE BALLINGER LAND CO,.'S PLAT SUBDIVISION NO. 1, ACCORDING TO THE PLAT THEREOF RECORDED IN VOLUME 9 OF PLATS. PAGES 57 AND 58 RECORDS OF SNO140MISH COUNTY, WASHINGTON. EXCEPT STATE HIGHWAY 102. TOGETHER WlT14 SHORE LANDS OF THE. SECOND CLASS AS CONVEYED BY THE STATE OF WASHINGTON BY DEED RECORDED UNDER .AUDITOR'S FILE NUMBER 326924, SITUATE IN THE COUNTY OF SNOHOMISH, STATE OF WASHINGTON, Detention for this Single Family residence is to be conventional underground pipe or tank sized by the pertinent Edmonds regulation for a house of this size (2,848 SF new and replacement impervious) with an internal restrictor and pipe conveyance to Lake Ballinger. The City by regulation would classified the Sport Court as a "Regulated" impervious surface under current City Ordinance. However, closer examination of the file revealed that the detention requirement was waived in writing by the Edmonds City Engineer on May 1, 1991. Therefore, sport court is herein treated as exempt due to a preexisting waiver. Edmonds requires a detention/infiltration design using the Western Washington Model as developed by the Department of Ecology (or equal) over 5,000 SF In this case, total regulated surface will be less than 5,000 SF. See the discussion in subsequent pages. WATER QUALITY AND TESC METHODS PROPOSED Type of water quality measure(s) proposed: 1. DOE Standard erosion control BMPs will be designed at the detailed construction ' plan stage such as mulch, seed, hay bales, sediment traps, plastic sheeting, sediment ponds and TESC entrances to control construction runoff, as required. ' 2. Mulching and other winter soil management techniques will be specified in the construction plans. J.C. McDonnell Engineering, PC 2 Trieu SFR Drainage Report 5/04/2012 REV.3 EXISTING CONDITIONS The site is a conventional two story single family house constructed on the Lake Ballinger shoreline in 1946 with surrounding driveway surfaces. The 3,500 SF sport court was added by Edmonds permit in 1990 according to the City project file. Detention was waived by the City Engineer on May 1, 1990. Over the years, there has been a persistent flooding problem within the Lake Ballinger drainage basin. Edmonds and Lake Forest Park have joined forces with an extensive program to improve the Lake downstream conditions and to reduce the incidence of flooding along the shoreline. The Snohomish County Soil Survey lists the site soil type as Alderwood Gravely Sandy Loam with 8 to 15 percent slopes and Mukilteo muck around the Lake shore area. The Gravely Sandy Loam corresponds to a type "C" soil with CN's of 81 to 85 depending upon the vegetation and cover conditions. Mukilteo muck is a poorly drained organic soil classified as D without good porosity characteristics. Soil classification is consistent with the wetlands flagged on the north end of the property. Temporary erosion control BMP's will be required to control erosion and potential silt ' production off the construction area until the site is stabilized and the landscaping is in place. DEVELOPED SITE CONDITIONS The proposed project will tear down the existing house footprint and construct approximately 3,451 SF of regulated new or replaced surface. No other significant changes are anticipated to the site except for installation of a natural gas storage tank and a small detention tank. The slope stability over the long term is the primary consideration with gravity discharge So onsite storm detention will be developed to minimize erosion risk to the downstream. Some Wetland Mitigation techniques may also be proposed to address surface sheetflow from a Sport Court surface located on the waterfront Based upon the analysis provided in this report, detention volume is designed from Table 1 for Small Sites provided by the City of Edmonds. This enclosed table provides standard storage volumes based upon the square footage of impervious to be constructed up to 5,000 SF. J.C. McDonnell Engineering, PC 3 Trieu SFR Drainage Report 5/04/2012 REV.3 DEVELOPMENT AREA DISTRIBUTIONS Site Development Area Distribution Total Property Area = 0.457 Acres, Development Area = 0.286 Acres, Existing Pervious = 0.245 Acres, Proposed Pervious = = 0.217 Acres Existing Impervious Area = 0.232 Acres, Proposed Impervious = 0. 228 Acres According to Figure D the new house is proposed to cover the footprint of the old house. The old house and related pavements were constructed before 1977. Therefore, all existing impervious surfaces repaired or replaced except the new house are "EXEMPT REPLACED". Only previously Pervious Surface that is now covered by New Construction is "REGULATED REPLACED". Based on our quantitative analysis of the drawing provided and adjusted for the AIA roofline: EXISTING CONDITIONS SA(SF) Non - Regulated Regulated Waived HOUSE 1,360 1,360 ASPH DRIVE 1,963 1,963 CONC D/W & SW 2,500 2,500 SPORT COURT 3,500 9,323 4,463 1,360 3,500 PROPOSED CONDITIONS SA(SF) Non - Regulated Regulated Waived NEW HOUSE 3,175 3,175 NEW CONC DRIVE 564 564 EXIST SW/ASPH COVERED BY NEW CONC DRIVE (58) (90) (58) (90) RESURFACED ASPH DRV CONC PAD Removed 1,963 (165) 1,963 (165) EX CONC PATIO NEW CONC. PATIO 1,580 100 1,580 100 SPORT COURT 3,500 3,500 10,569 3,378 3,691 3,500 J.C. McDonnell Engineering, PC 4 Trieu SFR Drainage Report 5/04/2012 REV.3 EDMONDS REQUIREMENTS: 1. Selected surfaces constructed after 1977 are defined as "regulated" and must be considered for detention. But the Sport Court, which falls into this category has A WRITTEN detention waiver since May 1990. It is also located below the 10-year flood elevation making detention physically impossible. ' 2. Developed IMPERVIOUS Areas over 5,000 SF are categorized as Small Site Category; 3. It appears from my discussion with Edmonds staff that the different surfaces identified as "regulated" can be addressed by different techniques to suit the site at hand. 4. Based upon Figure D of the Site Classification Worksheet, this Site is Small Site Category 1. Since "Regulated" surface is <5,000, Detention can be addressed from the City's Table 1. 5. Regulated surface for this project is 3,691-SF OR 3,700 SF 6. Site soils are GSL to 20" and clay below 20". Therefore, this Site is not suitable for Infiltration. 7. Detention is created for regulated surfaces only. Therefore, storm structures shall be closed with solid lids and shall receive only roof runoff and paved surface runoff from the new impervious surfaces as created. I J.C. McDonnell Engineering, PC 5 Trieu SFR Drainage Report 5/04/2012 REV.3 SITE HYDRAULIC ANALYSIS A. DESIGN CRITERIA The City of Edmonds Drainage Ordinance requires that storm water from new impervious surfaces created by development must be detained. The Drainage System Standard Plans further provides that if impervious development is less that the 5,000 sf threshold, a standard pre -tabulated City Drainage table can be used to develop the required storage volume. This site is eligible for the Standard Plans and is considered a Small Site Development under the Edmonds Stormwater Code Supplement. Since the house has been standing since 1948, it is reasonable to conclude that the replaced surfaces are indeed EXEMPT REPLACED by reason of longevity. The Site is a Category 1 Small Site since net impervious excluding the Sport Court (with waiver) is less than 5,000 SF of impervious. Category 1 Small Site Projects are subject to the following Minimum Requirements: ' 1. Small Site Development Requirement #1: Stormwater Site Plan Preparation The Stormwater Site Plan or Drainage Plan is included in the Project Plan Set. t 2. Small Site Development Requirement #2: Construction Stormwater Pollution Prevention Plan (SWPPP). The S WPP is included in the Plan set accompanying this report. 3. Small Site Development Requirement #3: Source Control of Pollutants Specific pollution source controls are not required for single family residential sites. General requirements for these sites include the preventing the discharge of pollutants to the City's storm drainage system per City code. 4. Small Site Development Reauirement #4: Preservation of Natural Drainaae Systems and Outfalls The preservation of the Natural Drainage System and Outfalls on this project assumes the ability to release detained runoff at the historical undeveloped rate as a point discharge or a sheet flow to Lake Ballinger shoreline including the Category 3 Wetland . 5. Small Site Development Reauirement #5: Onsite Control of Stormwater Onsite control of stormwater via infiltration is not an achievable alternative for this Site due to the types of soil present, the probability of a high water table on the lower portion of the lot, slope of the ground and the other geotechnical conditions of the site. The design detail of the drainage system on the Trieu property includes a small rooftop detention with gravity pipe and surface water release to sheetflow at the wetland buffer edge. J.C. McDonnell Engineering, PC 6 1 Trieu SFR Drainage Report ' 5/04/2012 REV.3 A. DESIGN CRITERIA ' 6. Small Site Development Requirement #7: Flow Control Flow control has been required by ordinance for regulated surfaces discharging ' into the downstream lake with complex flooding conditions. Trying to retrofit the sport court is problematic and the requirement has been waived. ' 7. Small Site Development Requirement #8: Wetland Protection Site does have a requirement for Wetland Protection. The Class 3 Wetland has ' been addressed in the project Wetland Delineation Report and is relevant to drainage considerations relative to the sport court. The house & sport court drainage provide the water supply to the wetland. 8. Small Site Development Requirement #9: Operation & Maintenance Documentation is required for any structural BMP such as the Detention System. Appropriate pages sited from the King County Drainage Manual are provided in the Appendix. II' 9. Small Site Development Requirement #11: Financial Liability This requirement for this single family residential site does not apply as the site development will not be constructed within any Critical Area. I - J.C. McDonnell Engineering, PC Trieu SFR Drainage Report ' 5/04/2012 REV.3 ' B. DETENTION VOLUME ' Based upon Edmond Handouts and Staff consultation, the following Options have been evaluated for this Project: ' Selected Option: We have demonstrated on Page 4 that the Site technically meets the definitions for a Small Category 1 site if the existing house surface is properly recognized as EXEMPT REPLACED Area. Therefore, it is our opinion that under Option 2, the Site can fulfill the drainage code requirement with a simple Detention System sized from Table 1 as follows: ' Proposed Impervious area = 3,691 SF(Assume 3,700 based on Edmonds Table 1) Design Detention = 124 CF (928 GAL) ' Table Pipe Equivalents Required= 40 LF of 24" Pipe (126 CF or 939 GAL) 48" SD Manhole Volume = 12.566 CF/Ft* 2 FT = 25.13 CF ' 1 - Type 1-L CB Volume = (28" x 32")/144 Sq.In. * 2'deep = 12.44 CF SDMHVolume = 25.13 CF ' CB#1 TYP 1-L = 12.44 CF 36 LF 24" * 3.1416 CF/FT = 113.1 CF Sub -total = 150.7 CF (1,127 GAL) Outlet Orifice requirements are as follows: For a 24" pipe Diameter = 0.625" orifice (5/8") J.C. McDonnell Engineering, PC 8 Trieu SFR Drainage Report 5/04/2012 REV.3 C. DOWNSTREAM CONDITIONS The Site drains directly to Lake Ballinger. Since the net increase of impervious surface will be approximately 850 SF, the project will not any noticeable effect on the Lake. However, it is understood that there are chronic seasonal flooding issues with this Lake and that they result primarily from urban runoff in the drainage basin. The problems within the Lake Ballinger Drainage Basin are well documented in the Lake Ballinger Fact Sheet (June 2011) as provided in the Appendix. J.C. McDonnell Engineering, PC 9 Trieu SFR Drainage Report 5/04/2012 REV.3 D. BUOYANCY ANALYSIS Pipe Cover Calculations Pipe Diameter (D) = 2 feet Pipe lV£tght* (W) = 24 1Wft3 Density of Soil (C',)= 120 lb; e Density, of Water (. ='�,i = 62.4lb'ft3 Pipe Area (A,) = 3.142 fi2 Bou)•an" Force: A� 172.0 lbift f ;" eQuireri frill: _ D _ Area Requnrec to balance F;_, (a) = F,;, ram', a = .1.434 fie. Solve for Depth (d): a=A,4-A3 Therefore: A, = d*D A$ =' 2. (I))2 a -A _ d DAt = 0.4 iag d = 0,50 feet Therefore use 1.0 feet of cover e Pipe weight assumes 16 gauge (0.064 inches) steel with Aluminized coating Thickness Max. height of 24" CNINF'r inches WITT.. OM2 20 0.064 24 0,079 29 S� S+r� N/Se- �"�) G S' lie�`i'`� d i The current design calls for cover of 2.0 feet over the pipe. Therefore, the cover will be sufficient to resist pipe buoyancy as long as the pipe is 16-gauge or better or has equivalent weight. J.C. McDonnell Engineering, PC 10 ' Trieu SFR Drainage Report 5/04/2012 REV.3 ENGINEERING REPORT APPENDICES IJ.C. McDonnell Engineering, PC 11 a To : Ma. Lyce CIMST MAN E06i 0.1El- Rio DCfk9 t4'r OP (;Ty of Epmo,o s RE : WA*-40 OF S;Di -P0. ;,ukfvf DETEAT;Oa FLOW olr 71Qq LWE a NWojarea Wky C-PO440JDS WA q8o U Kom : 1401 • POOPEaty OWN" DEK sta f lw- tMPu'cD 70-c PcArA;T Fc>a My OAU yAl D Sfoa? LOaaT PDZPK'ty I A-Np T'1asa6-0 0,32 w N v E4 CIvTiea 9M hfUk (9 Q I X W©OLP l." TO ma yoo& Dmr"iwr 6g0 V7 Tfff sysffm W AIVEf- of T14 E 1� DE DWN"i D'e TfWT,'D)J LLDW t&y pA-U YjM D POE io 7"fl cdF 00DTT;00S 40(M hi ; _. II is S-O FLAT A-M1 714i &CO0lu-b is 00IF . Tv, cct coMt)'T;4Ns ca&,T1= ►O rmposg,%LE s; WAT;ON F c A W A40it) r tipe`.S br.twfrb T44r W1�TFR WILL coMt y#-Izb N1 ocro r#ilE jPi Pr-S TIONK yo0 JrRy NWCdI (;PR yoJlt {.ouS.'AE-R-*Wom CaecE.I yoJe r ' Trieu SFR Drainage Report 5/04/2012 REV.3 SITE VICINITY AERIAL PHOTO IJ.C. McDonnell Engineering, PC 12 S.G. MCDONN£LL £NGiN££RING PC Consulting Civil Engineers l0l008- 2lloth Street SW Mountla0 Terrace, WA gSo43 (425) -M-oq* (T£L) (425) -N-og46 (FAX) e-mail: jcmcdon2@frontier.com Vicinity Map TRIEU SFR RESIDENCE 7109 Lake Ballinger Way Edmonds, WA. TAX ID: 00488800800700 SCALE: None DATE: SHEET: BY: JOB NUMBER: FILE NAME: Photobase 0 Trieu SFR Drainage Report 5/04/2012 REV.3 STORM DRAINAGE SIZING QUALIFICATIONS FIGURES D & E WITH DEFINITIONS I J.C. McDonnell Engineering, PC 13 Figure-D What Qualifies as Replaced Impervious Surface? Is the Impervious Area being removed and replaced with new impermeable surface in the same footprint? Yes No Was the existing impervious area created prior to 7/7/1977 Yes or prior to the date the parcel was annexed from Snohomish County? No Area is NOT considered REPLACED impervious surface area Refer to Figure E for regulation of New Impervious Surface Areas Area is considered EXEMPT REPLACED impervious surface area Yes Is parcel zoned Yes Does the replaced impervious Single -Family Residential? area replace an existing driveway, walkway or patio in the same footprint AND will it remain the same use after replacement? No No Area is considered REGULATED REPLACED impervious surface area Revised on 4121111 E72-SWM Erosion_Control--04.21.1 ]-FINAL Page 8 of 13 ' Figure-E Regulation of NEW Impervious Surface Areas for Determining Site Classification Does the site have any existing impervious surface areas that were created on or after No after July 7, 19771? Yes ' Have City -approved stormwater controls3 been applied to all of the existing impervious areas? Yes ' For example, does the site have an existing stormwater management system that collects stormwater runoff from all of the existing impervious surfaces? No Only those areas proposed vith the project that are to bf converted from pervious surfaces (native vegetation, etc) to impervious surfaces and permeable pavements will be regulated as New Impervious Surface ' Does the existing impervious area Were the existing (not managed by an existing Yes impervious areas Yes stormwater system) exceed constructed prior to the 2,OOOsf? parcel being annexed into ' the City? No No ' Was a waiver from the requirement to install a stormwater management Yes All impervious surface areas created system granted for the existing ' on or after impervious area? July 7, 19772 plus No ' All impervious surface areas proposed with the project will be regulated as ' New Impervious Surface Area Note: For the purpose of this flowchart, it is assumed that all existing impervious surface will remain after the proposed project is complete. If any existing impervious surface will be demolished for this project, the project may contain a combination of new and replaced impervious surface. See Glossary, p. 10-11. Mitigation requirements are based on the total cumulative impervious area created on a project site since July 6, 1977, the effective date of the City's first drainage control ordinance. ' z For parcels that were annexed into the City after this date, the date of annexation shall substitute for the effective date of the City's first drainage control ordinance. 3 For annexed parcels, a functioning Snohomish County -approved stormwater management facility can substitute for a City -approved facility. Revised on 4121111 E72-SWM_Erosion_Control--04.21.11-FINAL Page 9 of 13 Glossary This glossary provides explanations of the terminology used in this handout. The actual definitions can be found in ECDC Chapter 18.30.010 or the Supplement. Impervious Surface: Hard surface area that either prevents or retards the entry of water into the ground as it would occur in natural, undeveloped conditions. Impervious surfaces include, but ale not limited to, rooftops, driveways, walkways, concrete, asphalt, and packed earthen materials. Decks will be considered impervious if one or more of the following apply: • Deck is made of "solid" material that does not allow rain water to run through it • Deck has "slots" where rainwater can run through but the ground under the deck does not allow the rainwater to infiltrate into the ground. Open, uncovered retention/detention facilities shall not be considered impervious surfaces for purpose of determining whether the thresholds for application of minimum requirements are exceeded. However, open, uncovered retention/detention facilities shall be considered impervious surfaces for purposes of runoff modeling. Outdoor swimming pools shall be considered impervious surfaces in all situations. ' For the purpose of determining stormwater control requirements, impervious surfaces are divided into four categories: "Non -Regulated", "Exempt Replaced", "Regulated Replaced ", and "New". See explanations below: ' Non -Regulated Impervious Surface: All impervious surface area installed prior to July 7, 1977 or prior to the date the parcel was ' annexed into the City from Snohomish County that will remain unchanged during the site redevelopment. Replaced Impervious Surface: ' All impervious surface area on the project site existing at the time of application that is proposed to be removed and re-established in the same footprint. This does not include impervious surface removed for the sole purpose of installing utilities or performing maintenance. ' "Exempt Replaced" - Some of the replaced impervious surface may be "Exempt" if it meets the following condition: ' On single-family residential parcels only: the replacement of a driveway, walkway, or similar surface in the same footprint in which it was originally installed prior to July 7, 1977 or prior to the date the parcel was annexed into the City from Snohomish County. ' "Regulated Replaced" - All other replaced impervious surfaces on any parcel that do not qualify as "Exempt" are considered "Regulated." New Impervious Surface: All areas converted from pervious surfaces (native vegetation, etc.) to impervious surfaces and permeable pavements on a project site on or after July 7, 1977 or the date the parcel was annexed 3 Removed refers to the removal of building down to bare soil or subgrade. Roof replacement such as re -shingling, is considered to be a maintenance ' activity and not considered replacing an impervious surface. For others surfaces, such as pavement, "removed" means the removal of concrete (PCQ or asphalt (AC) slabs, driveways, sidewalks or similar surfaces down to bare soil or base course. The pulverization in -place and replacement with a similar wearing course is considered replaced impervious surface. The partial grinding of surfaces for overlay (not down to base soil or base course) is considered to be a maintenance activity. ' Revised on 4121111 E72-SWM Erosion_Control--04.21.11-FINAL Page 10 of 13 into the City from Snohomish County. See Figure-E for exemptions for sites located outside of Creek or Lake drainage basins. Land -disturbing Activity: Any activity that results in movement of earth, a change in the existing soil cover (both vegetative and non -vegetative), or in the existing soil topography. Land -disturbing activities include but are not limited to clearing, grading, filling, excavation, and compaction of soils associated with structure stabilization and road construction. Pervious Surface: Any surface that allows the entry of water into the ground as it would occur in nature. Revised on 421/11 E72-SWM Erosion_Control--04.21.11-FINAL Page 11 of 13 Trieu SFR Drainage Report 5/04/2012 REV.3 SITE CLASSIFICATION WORKSHEET I J.C. McDonnell Engineering, PC 14 City of Edmonds F EDyto� o Site Classification Worksheet'"'"` Page 1 of 2 "C. 1g9cj The project's Site Classification will dictate the specific stormwater management requirements applicable to your site. Completing this worksheet will help determine the amount of regulated impervious surface and whether your project falls into the classification of a Small Site (Category 1 or Category 2), or a Minor Site. Please reference the Glossary (pp. 10-11), Figures D and E, (pp. 8-9), and Examples (pp. 12-13), to assist with completion of this worksheet. 1) Is Permeable Pavement' Proposed For Use on this Site? ❑ Yes ❑ No Refer to Stormwater Supplement Chapter 5.1 If YES, the subject area is to be considered impervious for initial site classification purposes. Include total permeable pavement area in the calculation of Non -Regulated, 1�, Replaced and/or New impervious surface areas in the table below. 2) Determine the Amount and Type of Existing & Proposed Impervious Surface for the Site Refer to Stormwater Supplement Chapter 2 and Fig. C Line 1: Identify the Non -Regulated Impervious Surface Area. Line 2: Identify the Replaced Impervious Surface Area, dividing the total between Exempt and Regulated; either or both may be zero. Note: For project classification purposes, Replaced Impervious may only be considered exempt under certain conditions. Refer to the Glossary and Figure D. Line 3: Identify the New Impervious Surface Area for your project. All impervious areas created post -July 7, 1977 or after the date of annexation into the City are regulated & should be included in this total unless they can be categorized separately as a Replaced -Regulated area. Line 4: Enter the sum of the total Replaced -Regulated plus the total New impervious areas. Line 5: Identify the total area currently mitigated by an existing city -approved stormwater management system. Line 6: Enter the sum of the value in Line 4 less the value in Line 5 to identify the total Regulated area in which stormwater controls have not yet been applied. Line 7: Identify the total area proposed to be mitigated through the use of Low Impact Development Techniques. Line 8: Identify the total area proposed to be mitigated through conventional Stormwater Management Techniques. ** Provide a copy of the following table on the drainage plan sheet for the proposed project ** Line Type Area (square feet) 1. Non -Regulated 069 7 g 5.F Exempt Regulated 2. Replaced 6 4 6 sr-) 175 &F 3. 4. New (Post 1977) 4 4 4 4 4 4 4 4 4 + OOOa'.'®C.®6.SOt✓da9CG'C9OA0®9G:0m/.J9m�m0'®00- Total Regulated Impervious Area = Mitigation required if in excess of 2000s GG 415 Q/ 5. .Y60.A8 6. Total Area Mitigated b Existin Stormwater Management System(s) - g Y g gE 9.L:9'.4:er:O.O.'L:'d.0iT3T.Sd:G,0.6aPJ.B.I'9.06"O.9L�Ii"B.:Y9:C:(1:�3':B'Y9.:d:.Y.:L'iT•:C:TLi':RO.d.6':O. S:t' , Regulated Area Not Yet Mitigated i 7. Area Proposed to be Mitigated by Low Impact Development Techniques '•. _ 8. Area Proposed to be Mitigated through Conventional SWM Techniques 1 (e.g. porous asphalt, porous concrete, paver blocks, concrete open celled paving grids, or plastic lattices filled with turf or stone) Revised on 4/21/11 E72-SWM_Erosion_Control-Draft-04.21.11-FINAL Page 5 of 13 City of Edmonds F°"� a Site Classification Worksheet Page 2 of 2 "° 1g90 3) Determine the Total Area of Land Disturbing Activity � A Refer to Stormwater Supplement Chapter 8 4) Determine the Quantity of Grading, Fill and/or Excavation C cy 5) Will the project convert 3/ Acre or More of Native Vegetation to Lawn or ❑ yes VoNo Landscaped Area? 6) Identify the Watershed the Existing Site Runoff Discharges to Refer to Stormwater Supplement Chapter 2.3 Based on Site Location and Watershed Map — Figure-C. Check all that apply. ' A. ❑ Direct Discharge B. VCreek or Lake Basin ❑,Edmonds Way Basin ' ❑ Puget Sound Basin ❑ Puget Sound Piped Basin DETERMINE PROJECT CLASSIFICATION USING THE INFORMATION ABOVE AND THE PROJECT CLASSIFICATION CHART (Figure B, pg 4) ❑ Small Site - Category 1 1Y Small Site - Category 2 ❑ Minor Site Stormwater Supplement Stormwater Supplement Stormwater Supplement Chapter S Chapter S ; ' ., Chapter 6 I' Revised on 4121111 E72-SWM _ Erosion_Control-Draft-04.21.11-FINAL Page 6 of 13 Trieu SFR Drainage Report t 5/04/2012 REV.3 DETENTION SIZE TABLE '' J.C. McDonnell Engineering, PC 15 Table 1 Detention Pipe Look -Up Table Category 1 Small Site Projects Contributing New Plus Replaced Impervious Surface Area (sf) Length of Pipe ft For Given Inside Diameter 18-inch 24-inch 30-inch 36-inch 2,000 41 22 15 11 2,500 49 30 18 12 3,000 61 33 23 16 3,500 74 38 24 17 4,000 91 45 29 20 4,500 95 49 32 23 5,000 112 56 35 25 sf — square feet Orifice Size: 0.5 (1/2) inch diameter = 0.75 (314) inch diameter = 0.625 (5/8) inch diameter = 0.875 (7/8) inch diameter Outlet pipes (including in the flow control structure) must be 8 in diameter for 2,000 to 4,000 square feet of new plus replaced impervious surface area. Outlet pipes (including in the flow control structure) must 10 in diameter for greater than 4,000 square feet of new plus replaced impervious surface area. Note: Multiple pipes in parallel connected together (manifolded) can be used to meet length requirements, if site has constraints. Table 2 Approved Detention Pipe Material and Catch Basin/Manhole Structure Sizing Detention Pipe Inside Diameter WDOT (inches) Detention Pipe Material Catch Basin/Manhole 18 All types in list below table Type 1L Catch basin 24 All types in list below table Type 2, 48-inch diameter manhole 30 Ali Metal & RPP Type 2, 48-inch diameter manhole All Concrete & CPEP Type 2, 54-inch diameter manhole PVCP Type 2, 60-inch diameter manhole F_ 36 Metal & RPP Type 2, 54-inch diameter manhole All concrete, CPEP, & PVCP Type 2, 60-inch diameter manhole WDOT — Washington Department of Transportation List of Approved Pipe Materials for Detention Metal. ACSP — Aluminized Corrugated Steel Pipe (Type 2 meets AASTO designations M274 and M36) ASRP - Aluminum Spiral Ribbed Pipe (16 gauge or better) CAP —Corrugated Aluminum Pipe (16 gauge or better) DIP — Ductile Iron Pipe (Class 50 or better) Concrete: PCP — Plain Concrete pipe RCP — Reinforced Concrete Pipe -2- Plastic: PVCP — Polyvinyl Chloride Pipe (SDR 35 or better) CPEP — Corrugated Polyethylene Pipe (smooth interior wall, or N-129 pipe) RPP- Ribbed Polyvinylchloride Pi Trieu SFR Drainage Report 5/04/2012 REV.3 OPERATION & MAINTENANCE TECHNIQUES J.C. McDonnell Engineering, PC 16 I KING COUNTY, WASHINGTON, SURFACE WATER DESIGN MANUAL KING COUNTY, WASBINGTON SURFACE WATER DESIGN MANUAL APPENDIX A MAINTENANCE REQUIREMENTS FOR PRIVATELY MAINTAINED DRAINAGE FACILITIES Section No. Subiect 2 Infiltration 3 Closed Detention Systems 4 Control Structure/ Flow Restrictor 5 Catch Basins 14 10 1 Conveyance Systems A�}9ie�il�re�4ieA•6wwl e . Weips l�e�lls s ' s ale 9/1/98. APPENDIX A MAINTENANCE STANDARDS FOR PRIVATELY MAINTAINED DRAINAGE FACILITIES NO.2 - INFILTRATION ' Maintenance Defect Conditions When Maintenance Results Expected When Component Is Needed Maintenance Is Performed ' General Trash & Debris See 'Ponds" Standard No.1 See "Ponds" Standard No. 1 Poisonous Vegetation See "Ponds' Standard No.1 See 'Ponds' Standard No. 1 Pollution See "Ponds' Standard No. 1 See "Ponds' Standard No. 1 Unmowed Grass/ See "Ponds' Standard No. 1 See "Ponds" Standard No. 1 Ground Cover Rodent Holes See "Ponds" Standard No. 1 See 'Ponds" Standard No. 1 ' Insects See 'Ponds' Standard No. 1 See "Ponds" Standard No. 1 Storage Area Sediment A percolation test pit or test of facility indicates Sediment is removed and/or facility. facility is only working at 90% of its designed is cleaned so that infiltration system capabilities. If two inches or more sediment is works according to design. ' present, remove. Sheet Cover (If Sheet cover is visible and has more that three Sheet cover repaired or replaced. Applicable) 1/4-inch holes in it. ' Sump Filled with Any sediment and debris filling vault to 10% of Clean out sump to design depth. Sediment and Debris depth from sump bottom to bottom of outlet pipe (If Applicable) or obstructing flow into the connector pipe. Filter Bags Filled with Sediment Sediment and debris fill bag more than 1/2 full. Replace filter bag or redesign ' and.Debris system. Rock Filters Sediment and Debris By visual inspection, little or no water flows Replace gravel in rock filter. through filter during heavy rain storms. Side Slopes of Pond Erosion See "Ponds' Standard No. 1 See "Ponds' Standard No.1 Emergency Rock Missing See "Ponds' Standard -No. 1 Overflow Spillway Settling Ponds and Sediment Remove when 6" or more. ! Vaults Note: Sediment accumulation of more than .25 inches per year may indicate excessive erosion is occurring upstream of the facility or that conveyance systems are not being properly maintained. The contributing drainage area should be checked for erosion problems or inadequate maintenance of conveyance systems if excessive sedimentation is noted in an infiltration facility. Check twice a year during first 2 years of operation, once a year thereafter. Clean manholes/catch basins, repair damaged inlets/outlets, clean trash racks. 4 1 ' r 9/1/98 A-2 1998 Surface Water Design Manual APPENDIX A MAINTENANCE STANDARDS FOR PRIVATELY MAINTAINED DRAINAGE FACILITIES NO.3 - CLOSED DETENTION SYSTEMS (PiPESITANKS) Maintenance Defect Conditions When Maintenance is Needed Results Expected When Component Maintenance is Performed Storage Area Plugged Air Vents One-half of the cross section of a vent is blocked at Vents free of debris and any point with debris and sediment sediment Debris and Accumulated sediment depth exceeds 10% of the All sediment and debris Sediment diameter of the storage area for Y2 length of storage removed from storage area. vault or any point depth exceeds 15% of diameter. Example: 72-inch storage tank would require cleaning when sediment reaches depth of 7 inches for more than Y2 length of tank. Joints Between Any crack allowing material to be transported into All joint between tank /pipe Tank/Pipe Section facility sections are sealed Tank Pipe Bent Any part of tank/pipe is bent out of shape more than Tank/ pipe repaired or replaced Out of Shape 10% of its design shape to design. Manhole Cover Not in Place Cover is missing or only partially in place. Any open Manhole is closed. manhole requires maintenance. Locking Mechanism cannot be opened by one maintenance Mechanism opens with proper Mechanism Not person with proper tools. Bolts into frame have less tools. Working than YE inch of thread (may not apply to self-locking lids.) Cover Difficult to One maintenance person cannot remove lid after Cover can be removed and Remove applying 80lbs of lift. Intent is to keep cover from reinstalled by one maintenance sealing off access to maintenance. ' person. Ladder Rungs King County Safety Office and/or maintenance person Ladder meets design standards Unsafe judges that ladder is unsafe due to missing rungs, allows maintenance person safe misalignment, rust, or cracks. access. Catch Basins See "Catch Basins" Standards No. 5 See "Catch Basins" Standards No. 5 1998 Surface Water Design Manual. 9/1/98 A-3 APPENDIX A MAINTENANCE STANDARDS FOR PRIVATELY MAINTAINED DRAINAGE FACILITIES NO.4 - CONTROL STRUCTURE/FLOW RESTRICTOR Maintenance Defect Condition When Maintenance is Needed Results Expected When Component Maintenance is Performed General Trash and Debris Distance between debris build-up and bottom of All trash and debris removed. (Includes Sediment) orifice plate is less than 1-1/2 feet. Structural Damage Structure is not securely attached to manhole wall Structure securely attached to and outlet pipe structure should support at least wall and outlet pipe. 1,000 Ibs of up or down pressure. Structure is not in upright position (allow up to Structure in correct position. 10% from plumb). Connections to outlet pipe are not watertight and Connections to outlet pipe are show signs of rust. water tight; structure repaired or replaced and works as designed. Any holes —other than designed holes --in the Structure has no holes other structure. than designed holes. Cleanout Gate Damaged or Missing Cleanout gate is not watertight or is missing. Gate is watertight and works as designed. Gate cannot be moved up and down by one Gate moves up and down easily maintenance person. and is watertight. Chain leading to gate is missing or damaged. Chain is in place and works as designed. Gate is rusted over 50% of its surface area. Gate is repaired or replaced to meet design standards.. Orifice Plate Damaged or Missing Control device is not working properly due to Plate is in place and works as missing, out of place, or bent orifice plate. designed. Obstructions Any trash, debris, sediment, or vegetation Plate is free of all obstructions blocking the plate. and works as designed. Overflow Pipe Obstructions Any trash or debris blocking (or having the Pipe is free of all obstructions potential of blocking) the overflow pipe. and works as designed. Manhole See "Closed Detention Systems" Standards No. 3 See "Closed Detention Systems' Standards No. 3 Catch Basin See "Catch Basins" Standards No. 5 See 'Catch Basins" Standards No. 5 9/1/98 1998 Surface Water Design Manual A-4 APPENDIX A MAINTENANCE STANDARDS FOR PRIVATELY MAINTAINED DRAINAGE FACILITIES NO.5 - CATCH BASINS ' Maintenance Defect Conditions When Maintenance is Needed Results Expected When Component Maintenance is performed ' General Trash & Debris Trash or debris of more than 1/2 cubic foot which is No Trash or debris located (Includes Sediment) located immediately in front of the catch basin immediately in front of catch opening or is blocking capacity of the basin by basin opening. more than 10% Trash or debris (in the basin) that exceeds 1/3 the No trash or debris in the catch depth from the bottom of basin to invert the lowest basin. pipe into or out of the basin. Trash or debris in any inlet or outlet pipe blocking more than 1/3 of its height. Dead animals or vegetation that could generate odors that could cause complaints or dangerous gases (e.g., methane). Deposits of garbage exceeding 1 cubic foot in volume Structure Damage to Comer of frame extends more than 3/4 inch past Frame and/or Top Slab curb face into the street (If applicable). Inlet and outlet pipes free of trash or debris. No dead animals or vegetation present within the catch basin. No condition present which would attract or support the breeding of insects or rodents. Frame is even with curb. Top slab has holes larger than 2 square inches or Top slab is free of holes and cracks wider than 1/4 inch (intent is to make sure cracks. all material is running into basin). Frame not sitting flush on top slab, i.e., separation Frame is sitting flush on top of more than 3/4 inch of the frame from the top slab. slab. Cracks in Basin Walls/ Cracks wider than 1/2 inch and longer than 3 feet, Basin replaced or repaired to ' Bottom any evidence of soil particles entering catch basin design standards. through cracks, or maintenance person judges that structure is unsound. Cracks wider than 112 inch and longer than 1 foot No cracks more than 1/4 inch at the joint of any inlet/ outlet pipe or any evidence wide at the joint of inlet/outlet of soil particles entering catch basin through pipe. cracks. Sediment/ Basin has settled more than 1 inch or has rotated Basin replaced or repaired to Misalignment more than 2 inches out of alignment. design standards. 1999 Surface Water Design Manual 9/1/98 A-5 APPENDIX A MAINTENANCE STANDARDS FOR PRIVATELY MAINTAINED DRAINAGE FACILITIES - NO. 5 - CATCH BASINS (CONTINUED) ' Maintenance Defect Conditions When Maintenance is Needed Results Expected When Component Maintenance is performed Fire Hazard Presence of chemicals such as natural gas, oil and No flammable chemicals j t gasoline. present. Vegetation Vegetation growing across and blocking more than No vegetation blocking opening 10% of the basin opening. to basin. ' Vegetation growing in inlet/outlet pipe joints that is No vegetation or root growth more than six inches tall and less than six inches present. apart. ' Pollution Nonflammable chemicals of more than 1/2 cubic foot No pollution present other than per three feet of basin length. surface film. t Catch Basin Cover Cover Not in Place' Cover is missing or only partially in place. Any open Catch basin cover is closed catch basin requires maintenance. Locking Mechanism Mechanism cannot be opened by on maintenance Mechanism opens with proper Not Working person with proper tools. Bolts into frame have less tools. ' than 1/2 inch of thread. Cover Difficult to One maintenance person cannot remove lid after Cover can be removed by one Remove applying 80 lbs. of lift; intent is keep cover from maintenance person. ' sealing off access to maintenance. Ladder Ladder Rungs Ladder is unsafe due to missing rungs, misalignment, Ladder meets design standards Unsafe rust, cracks, or sharp edges. and allows maintenance person ' safe access. Metal Grates Grate with opening wider than 7/8 inch. Grate opening meets design (If Applicable) standards. Trash and Debris Trash and debris that is blocking more than 20% of Grate free of trash and debris. grate surface. Damaged or Grate missing or broken member(s) of the grate. Grate is in place and meets ' Missing. design standards. NO.6 DEBRIS BARRIERS (E.G., TRASH RACKS) ' Maintenance Defect Condition When Maintenance is Needed Results Expected When Components Maintenance is Performed. ' General Trash and Debris Trash or debris that is plugging more than 20% of Barrier clear to receive capacity the openings in the barrier. flow. Metal Damaged/ Missing Bars are bent out of shape more than 3 inches. Bars in place with no bends more ' Bars. than 3/4 inch. Bars are missing or entire barrier missing. Bars in place according to design. ' Bars are loose and rust is causing 50%deterioration Repair or replace barrier to to any part of barrier. design standards. 911/98 1998 Surface Water Design Manual I A-6 ' APPENDIX A MAINTENANCE STANDARDS FOR PRIVATELY MAINTAINED DRAINAGE FACILITIES NO.10 - CONVEYANCE SYSTEMS (PIPES & DITCHES) Maintenance Defect Conditions When Maintenance is Needed Results Expected When Component Maintenance is Performed Pipes Sediment & Debris Accumulated sediment that exceeds 20% of the Pipe cleaned of all sediment ' diameter of the pipe. and debris. Vegetation Vegetation that reduces free movement of water All vegetation removed so water through pipes. flows freely through pipes. ' Damaged Protective coating is damaged; rust is causing Pipe repaired or replaced. more than 50% deterioration to any part of pipe. ' Any dent that decreases the cross section area of Pipe repaired or replaced. pipe by more than 20%. Open Ditches Trash & Debris Trash and debris exceeds 1 cubic foot per 1,000 Trash and debris cleared from ' square feet of ditch and slopes. ditches. Sediment Accumulated sediment that exceeds 20 % of the Ditch cleaned/ flushed of all design depth. sediment and debris so that it matches design. ' Vegetation Vegetation that reduces free movement of water Water- flows freely through through ditches. ' ditches. Erosion Damage to See "Ponds" Standard No. 1 See "Ponds" Standard No. 1 ' Slopes Rock Lining Out of Maintenance person can see native soil beneath Replace rocks to design Place or Missing (If the rock lining. standards. Applicable). Catch Basins See "Catch Basins: Standard No. 5 See "Catch Basins" Standard No. 5 If Debris Barriers See "Debris Barriers" Standard No.6 See "Debris Barriers" Standard (e.., Trash Rack 9 ) No. 6 NO.11 - GROUNDS (LANDSCAPING) Maintenance Defect Conditions When Maintenance Is Needed Results Expected When Component Maintenance is Performed General Weeds Weeds growing in more than 20% of the landscaped Weeds present in less than 5% (Nonpoisonous) area (trees and shrubs only). of the landscaped area. Safety Hazard Any presence of poison ivy or other poisonous No poisonous vegetation ' vegetation. present in landscaped area. Trash or Litter Paper, cans, bottles, totaling more than 1 cubic foot Area clear of litter. within a landscaped area (trees and shrubs only) of ' 1,000 square feet. Trees and Shrubs Damaged Limbs or parts of trees or shrubs that are split or Trees and shrubs with less than broken which affect more than 25% of the total 5% of total foliage with split or foliage of the tree or shrub. broken limbs. ' Trees or shrubs that have been blown down or Tree or shrub in place free of knocked over. injury. Trees or shrubs which are not adequately supported Tree or shrub in place and or are leaning over, causing exposure of the roots. adequately supported; remove any dead or diseased trees. 1998 Surface Water Design Manual 9/1/98 1 A-9 ' Trieu SFR Drainage Report ' 1/20/2012 SITE DOWNSTREAM CONDITIONS REPORT IJ.C. McDonnell Engineering, PC Lake Ballinger Fact Sheet Revision Date: June 15, 2011 As a result of flooding events in August 2004, the City of Mountlake Terrace was contacted by several Edmonds residents on Lake Ballinger concerned about the high water level on the lake. In an effort to address this issue and others that were raised during discussions, the following "Lake Ballinger Fact Sheet" along with a chronological list of developments was prepared and distributed to lake residents. Information regarding the level of the lake, storm water inflow to the lake, water quality of the lake, and the ongoing efforts of the City of Mountlake Terrace, the City of Edmonds, and several other adjacent agencies to address these issues is included in this fact sheet. The fact sheet is periodically updated as new information becomes available. Lake Ballinger Fact Sheet: Watershed Area: Shoreline 22%, Snohomish County 9%, Mountlake Terrace 23%, Edmonds 25%, Lynnwood 21% Size: 107 acres (including the island) — 72 acres in Mountlake Terrace and 35 acres in Edmonds Depth: Deepest depth is approximately_ 35 feet Private Ownership: Three lots in Mountlake Terrace, 49 in Edmonds, Nile Temple Property Public Ownership: Lake Ballinger Golf Course, Lake Ballinger Swimming Beach and Dock Drainage Basins: Hall Creek — 66 percent of inflow Echo Lake, Aurora Village — 16 percent of inflow Non-specific areas adjacent to the lake — 18 percent of inflow Lake Ballinger Events: - 1942 - Lake Level Established by Court Order o Authorized installation of a lake outflow weir on McAleer Creek o Authorized formation of a tax district to pay for maintenance and operation of the weir - 1954 - Mountlake Terrace Incorporates - Mid 1960's - Nile Temple filled in an area north of the existing creek site -and raised the roadbed area near the first culvert downstream on McAleer Creek effectively creating a higher roadbed and effectively raising the high overflow level of the lake during large storm events. Prior to this work, high water levels that exceeded the height of the weir flowed around the roadbed and culvert at a lower high overflow elevation. Lake Ballinger Fact Sheet ' June 15, 2011 Page 2 - Early 1970's - Staff notices and takes reports from residents about Lake Ballinger water quality issues. - 1972 - Department of Ecology (DOE) study finds that Lake Ballinger has the poorest water quality of 34 lakes surveyed in the Puget Sound area. - 1973 - First Lake Ballinger Report compiled by consultant to begin background assessment of water quality. - 1974 - Second Lake Ballinger Report prepared as part of the Lakeview Drive Road Construction Project indicating ongoing nutrient issues with the lake causing algae blooms. - Mid 1970's - Resident Bob Boye begins to release Chinook fry to the lake and helps to develop the Salmon in the Classroom program with the Department of Fish and Wildlife. - 1976 - Interlocal agreement with Edmonds, King County and Mountlake Terrace to study Lake Ballinger in more detail through King County Metro project. - 1977 - King County Metro study published with recommendations for improvements to Lake Ballinger. - 1978 - Mountlake Terrace receives a grant from DOE and EPA to improve water quality. - 1979 - Mountlake Terrace contracts with Kramer Chin & Mayo to design water quality improvements. 1980 - Construction begins on water quality improvements to Hall Creek (bank restoration and two instream sedimentation ponds) and McAleer Creek (bank improvements, removal of accumulated sediment in creek channel and construction of a new weir at the original site on Nile Temple property). - 1982 - Mountlake Terrace coordinates the readjudication process to reset the level of Lake Ballinger to reduce flooding and drainage impacts due to storm events and to allow operation of ' new water quality piping system in the lake. - 1982 - Work is completed on installation of a Hypolirnnetic Injection System to transport ' oxygen rich water from Hall Creek to the bottom of the lake and remove oxygen -depleted water from the bottom of the lake to an outlet at the weir on McAleer Creek. t- Mid 1980's - Several pump failures at the Ballinger Sanitary Sewer Pump Station result in Lake Ballinger Fact Sheet June 15, 2011 Page 3 sewer spills to McAleer Creek and Lake Ballinger. - 1985 - Mountlake Terrace hires a water quality specialist, sets up a water quality lab and begins monitoring efforts in the Lake Ballinger Basin. - 1987 The State of Washington begins efforts to coordinate water quality and stormwater ' runoff issues in Puget Sound through stormwater management and resource protection by forming a Puget Sound Water Quality Authority. ' - 1987 - Mountlake Terrace adopts a new stormwater code for development and water quality control. ' - 1991 - Mountlake Terrace implements a project to treat the lake with alum to help reduce nutrient levels through an Ecology Water Quality grant. - 1991 - New sanitary sewer pump station installed by King County Metro to replace the old City operated Lake Ballinger Pump Station. 1992 - Third Lake Ballinger Water quality report published which indicates that the water quality improvements installed in the 1980's are continuing to provide interim treatment and protection, but that continued basin -wide stormwater management is needed to prevent additional degradation of the lake. 1993 - Water quality specialist leaves city employment along with the lab technician — water quality lab is dismantled - water quality program is reduced to minimum level for necessary maintenance and complaint response. ' - 1993 - Total Maximum Daily Load (TMDL) listing for excess phosphorous is developed by Ecology as part of the water quality plan published in the 1985 final grant report for Lake Ballinger by Kramer, Chin, and Mayo. - 1995 - Nile Temple Golf Course remodel making an 18-hole course from the original nine -hole course. - 1996 - State forms the Puget Sound Water Quality Action Team within the Puget Sound Water Quality Authority to review and update management efforts to protect and restore the Sound, and to coordinate with local agencies. - .1996-7 New Years Day - Major snow storm and subsequent rainfall raises lake level to an J q ' elevation of 283.5 feet, six feet above normal winter elevation — several structures on the south Lake Ballinger Fact Sheet ' June 15, 2011 Page 4 ' side of the lake are flooded — the sanitary sewer trunk line on the west side of the lake overflows into the water over a period of several days. ' - Spring 1997 - City of Mountlake Terrace and City of Edmonds staff meet with impacted homeowners to discuss possible mitigation measures — the meeting took place at the home of Mr. John Greenwold — no conclusions were reached as remedies would all likely involve the ' Nile Temple - Nile goes on record as opposing the lowering of the lake and would require compensation for any disrupted play as a result of any work accomplished on Nile property related to the lake level. ' - 1999 - Ballinger Recreation, Inc completes Lake Ballinger Golf Course rehabilitation. - 1999 October - Chinook Salmon are listed as a threatened species in several locations in Washington State, including Puget Sound and Lake Washington. - 2000 January - Mountlake Terrace forms a separate Storm Water Utility separate from the Water and Sewer Utilities to provide dedicated funding to storm water management activities. - 2000 - Puget Sound Water Quality Management Plan encourages adoption of more stringent regional stormwater requirements. - 2001 May - City adopts the 2001 DOE Stormwater Management Manual for Western Washington for all new development proposals. - 2003 October - Lake Ballinger resident Bob Boye reports the presence of a 15-pound Chinook salmon near his neighbors dock — Bob believes this the first returning salmon he has seen from one of his hatchery releases. - 2004 August - Two major summer storms cause localized flooding and a higher than normal lake level. - 2005 January — Meeting between City of Mountlake Terrace, City of Edmonds and the Lake Ballinger Community Association. Periodic meetings are held between staff members of each City and the Lake Ballinger Community Association. - 2005 September - City of Mountlake Terrace enters into an agreement with Tyrone and Carole Hardy to run the Ballinger Lakes Golf Course. - 2005 Fall - Heavy rainfall results in a higher than normal lake level. Lake Ballinger Fact Sheet June 15, 2011 Page 5 ' - 2006 January - Heavy rainfall again results in a higher than normal lake level — 279.4. - 2006 December — Heavy rainfall results in lake level of 279.5. - 2007 June — Representatives from Mountlake Terrace, Lynnwood, Shoreline, Edmonds, Lake Forest Park and the Lake Ballinger Community Association meet to discuss water quantity and ' water quality issues in the Lake Ballinger Basin. Each jurisdiction and the Lake Ballinger Community Association agree to pursue a watershed plan. ' - 2007 November — Testing is performed for the first time to identify specific species of algae present in a bloom on the lake. Toxic blue-green algae are present but the toxin level is below the level of concern according to the Snohomish Health District. - 2007 December - Heavy rainfall is experienced in the Lake Ballinger Basin. 5.6 inches of rain falls in a 36-hour period between 6:00 am Sunday morning December 2°a and 6:00 pm Monday I' December 3`d at the Mountlake Terrace Public Works Facility. Streets are flooded in many low-lying areas of the basin with multiple street closures. At least three homes are flooded on Lake Ballinger and six properties are flooded on Hall Creek between Lake Ballinger and 2201h ' St. SW. Lake Ballinger Reaches an elevation of 280.6, the second highest level since recording began in 1981. Sewage flows into the lake from at least one location on the Edmonds side and from two locations on Hall Creek in Mountlake Terrace. ' - 2008 March — State Legislature authorizes $200,000 to study surface water and ground water impacts to the level of Lake Ballinger. t- 2008 August — Lake Ballinger/McAleer Creek Forum Interlocal Agreement prepared to develop a Strategic Action Plan for the watershed. - 2008 November — Lake Level Study by Edmonds, Mountlake Terrace and Shoreline completed and presented to Lake Ballinger/McAleer Creek Forum. - 2008 November — A public meeting is held at the Ballinger Lakes Golf Course for input into the development of the Strategic Action Plan. - 2009 May — A second public meeting is held at the Ballinger Lakes Golf Course for final input into the Strategic Action Plan. - 2009 July — The Strategic Action Plan is accepted by the Forum. - 2010 January —A Capital Improvement Program is adopted by the Forum. Lake Ballinger Fact Sheet ' June 15, 2011 Page 6 ' - 2010 September — A renewed interlocal agreement is implemented with Edmonds, Lake Forest Park, Mountlake Terrace and Snohomish County participating. ' - 2011 January — The Johnston Group is hired by the Forum to lobby for federal and state funding to assist with implementation of the Capital Improvement Program developed from the Strategic Action Plan. Issues raised by Lake Ballinger residents (at the January 2005 meeting): Taxing district for weir maintenance. The 1942 order and the 1982 adjudication provided a funding mechanism for the state and subsequently the City to maintain and operate the weir. The yearly assessment provides funds for the City to inspect, operate and maintain the weir and the McAleer Creek channel from the lake to the I-5 culvert crossing. The assessment is based on actual time spent by City staff the previous year to inspect and remove debris from the weir on McAleer Creek and to raise and lower the lake level. This assessment is collected and held by Snohomish County until a statement of yearly costs is received from the City. Upon release by the County, these funds are placed into the City Stormwater Utility Fund to reimburse actual expenses. 2. Level of lake. The 1942 Superior Court order set the minimum level of Lake Ballinger at 276.5 feet, with a maximum of 278.5 feet. The Director of Hydraulics for the State of Washington was identified to control and maintain the weir. The 1982 adjudication changed this level slightly and approved a new weir structure to replace the failing structure installed in the 1940's. The lake levels adhered to since 1982 are as follows: a. April 1 to June 15 277.0 ' b. June 15 to September 15 277.5 c. September 15 to October 31 277.0 d. October 31 to April 1 276.8 ' The court order also limits the discharge from the lake to no more than 60 cubic feet per second. This is slightly less than the maximum amount of water that can flow through the ' culverts on Nile Temple property and under Interstate 5. The maximum level of the lake is also not to exceed 278.5 more than once in any five-year period. ' 3. Nuisance Animals. The two major nuisance animals impacting Lake Ballinger are beavers and geese. ' a. Beavers. Beaver naturally make their way up McAleer Creek from Lake Washington Lake Ballinger Fact Sheet ' June 15, 2011 Page 7 ' and have, on occasion, damned McAleer Creek and created a nuisance for property owners on the lake by destroying small trees and shrubs. The City has a program in place to remove and relocate nuisance animals as needed. ' b. Geese. Geese have been present on the lake in large numbers since the early 1980's. As I am sure all the residents are aware of, geese droppings have been a major inconvenience on grass and lawns and are the major source of high fecal coliform ' counts in the past at the Lake Ballinger Swimming Beach. A variety of control methods have been used with limited success. The City currently has a contract with the Washington State Department of Agriculture to perform egg addling where nests can be ' found on City property around the lake. This procedure inhibits hatching by application of an oil film to the eggs. Combined with efforts of property owners around the lake to harass offending birds, the number of geese using the lake on a permanent basis appears ' to have dropped significantly. 4. Water Quality. ' a. General Water Quality. Lake Ballinger is an urban lake with urban runoff problems. Petroleum products from road runoff, nutrients from fertilizers'and high fecal coliform ' levels from domestic pets, animals and birds are the biggest contributors to the water quality problems in Lake Ballinger. The most cost effective method of pollution and nutrient control is at the source. The City has a comprehensive stormwater program that ' helps to address water quality through street sweeping, illicit discharge identification, spill response and stormwater facility inspections for commercial and multifamily sites. b. Algae Blooms. Algae blooms are caused by an excess of nutrients in the lake. Algae ' proliferate, die, and sink to the bottom of the lake. The process of decomposition removes oxygen from the lower reaches of the lake and makes it difficult for aquatic organisms to survive. The southern end of Hood Canal has been identified with the ' same lack of oxygen, primarily due to the nutrient issues from development runoff and failing septic tanks in the area. The Hypolimnetic piping system serves to help counter this effect by raising the oxygen content of water at the bottom of the lake. Mountlake Terrace participates in the Department of Ecology blue/green algae identification ' program. To date, blue/green algae has not been identified at a concentration that is harmful to people or pets. c. Swimmer's Itch. The Snohomish Health District monitors this issue and will post ' public swimming beaches in the event of an outbreak. 5. Water Quantity. The issue of the amount of water reaching Lake Ballinger during storm events has been the overriding issue of concern with resident in recent years. While all jurisdictions in the Lake Lake Ballinger Fact Sheet ' June 15, 2011 Page 8 ' Ballinger Basin have implemented more stringent stormwater detention standards in recent years, new development continues to add additional impervious surface area to the drainage basin every year. As a result of rainfall events that are occurring with increased intensity ' and duration, residents on Lake Ballinger can expect to see rapidly rising lake levels during future storm events. ' Public education and information is perhaps the most important element of the City of Mountlake Terrace stormwater program. Contacts with residents and sharing of information through fact sheets like this document are very much a part of the solution to water quality and quantity issues on the lake. ' Residents have a voice in this effort and can be very effective. This fact sheet and chronology of events regarding Lake Ballinger is intended to help to educate and inform residents about storm water issues related to Lake Ballinger. If you have any questions or have additional information to add to this ' document, please feel free to contact Stormwater Program Manager Mike Shaw at Mountlake Terrace Public Works, 425-670-8264 ext. 5105. IpwAstormwateAlake BaWngerU ake Ballinger Fact Sheet 6_15_2011 J.C. Mc DONNELL ENGINEERING, P.C. Consulting Civil Engineers 6608 — 216 Street SW; #306 Mountlake Terrace, WA. 98043 STORM DRAINAGE STUDY For HOA TRIEU SFR Located at 7109 Lake Ballinger Way Edmonds, WA. TAX ID.: 00488800800700 DEVELOPER: Mr. Hoa Trieu 7109 Lake Ballinger Way Edmonds, WA. 98026 Issue Date: January 20, 2012 Revision Date: February 22, 2012 2Id Revision Date: May 4, 2012 PREPARED BY: J. C. McDonnell, MS, PE Surveyor of Record: Green Land Surveying Edmonds & Soap Lake Tel: (206) 498-0979 MAY 2012 n,.u� LMNQ DFEPw71TmENT Zulauf, JoAnne From: Shuster, Jerry Sent: Thursday, May 17, 2012 11:22 AM To: Zulauf, JoAnne "'YOFF0 FILE2 Subject: Trieu SFR - Buoyancy calcs . Joanne, I reviewed the buoyancy calculations for the proposed detention pipe on page 10 of the Drainage Report for the aforementioned project. The calculations do not assume the worst case condition that the backfill above the pipe is saturated with flood water. Based the proposed location of the pipe, if the lake elevation is same as the top of the backfill or higher, the soils above the detention pipe will be inundated. This inundation will reduce the downward buoyant force on the detention pipe and may cause the pipe to float if the pipe is empty (See the following link if method of calculation is needed for the backfill : http://www.concrete- pipe.org/pdfdd/DD 22.pd0. Most likely the detention pipe will be full as well, weighing it down (this should be checked). For the purpose of complying with the City's storm drainage regulations, a change is not needed, but I wanted to bring this issue to the engineers attention. Please include this e-mail in the street file. Jerry Shuster, P.E. Stormwater Engineering Program Manager City of Edmonds 1215th Ave N. Edmonds, WA 98020 Desk Phone: 425-771-0220 x1323 Fax: 425-672-5750 shuster@ci.edmonds.wa.us J.C. Mc DONNELL ENGINEERING, P.C. Consulting Civil Engineers 6608 — 216 n Street SW; #306 Mountlake Terrace, WA. 98043 STORM DRAINAGE STUDY For HOA TRIEU SFR Located at 7109 Lake Ballinger Way Edmonds, WA. TAX ID.: 00488800800700 DEVELOPER: Mr. Hoa Trieu 7109 Lake Ballinger Way Edmonds, WA. 98026 Issue Date: January 20, 2012 Revision Date: February 22, 2012 2°d Revision Date: May 4, 2012 PREPARED BY: J. C. McDonnell, MS, PE Surveyor of Record: Green Land Surveying Edmonds & Soap Lake Tel: (206) 498-0979 I(OFF) 425 744-0916 (CELL) 425 359-2717 (FAX) 425 744-0946 ' Trieu SFR Drainage Report 5/04/2012 REV.3 ' EXECUTIVE SUMMARY ' The proposed project is a developed lot located at at 7109-Lake Ballinger Way (SR104) at south end of Lake Ballinger in Edmonds, WA. 98020. The Legal Description places the property in Section 05, Township 27N, Range 03E, WM. The existing site is fully ' developed residential lot sloping from Lake Ballinger Way (NE 2051h Street). Sewer, water, telephone and power utilities are active to the existing house (constructed in 1946). A municipal sewer main crosses the property between the house and the Lake. LEGAL DESCRIPTION, ASSESSOR'S PARCEL #0048a8OO8OO7OO ' PER DEED OF TRUST A.F.#200207120622 LOT 7, BLOCK 8, LAKE BALLINGER LAND CO.'S PLAT SUBDIVISION NO. 1, ACCORDING TO THE PLAT THEREOF RECORDED IN VOLUME 9 OF PLATS, PAGES 57 AND 58 RECORDS OF SNOHOMISH COUNTY, WASHINGTON.. EXCEPT STATE HIGHWAY 102. TOGETHER WITH SHORE LANDS OF THE SECOND CLASS AS CONVEYED BY THE STATE OF WASHINGTON BY DEED RECORDED UNDER AUDITOR'S FILE NUMBER 326924, SITUATE IN THE COUNTY OF SNOHOMISH, STATE OF WASHINGTON. � ' Detention for this Single Family residence is to be conventional underground pipe or tank sized by the pertinent Edmonds regulation for a house of this size (2,848 SF new and I' replacement impervious) with an internal restrictor and pipe conveyance to Lake Ballinger. The City by regulation would classified the Sport Court as a "Regulated" impervious surface under current City Ordinance. However, closer examination of the ' file revealed that the detention requirement was waived in writing by the Edmonds City Engineer on May 1, 1991. Therefore, sport court is herein treated as exempt due to a preexisting waiver. Edmonds requires a detention/infiltration design using the Western ' Washington Model as developed by the Department of Ecology (or equal) over 5,000 SF In this case, total regulated surface will be less than 5,000 SF. See the discussion in subsequent pages. ' WATER QUALITY AND TESC METHODS PROPOSED ' Type of water quality measure(s) proposed: 1. DOE Standard erosion control BMPs will be designed at the detailed construction ' plan stage such as mulch, seed, hay bales, sediment traps, plastic sheeting, sediment ponds and TESC entrances to control construction runoff, as required. 2. Mulching and other winter soil management techniques will be specified in the construction plans. ' J.C. McDonnell Engineering, PC 2 Trieu SFR Drainage Report 5/04/2012 REV.3 EXISTING CONDITIONS The site is a conventional two story single family house constructed on the Lake Ballinger shoreline in 1946 with surrounding driveway surfaces. The 3,500 SF sport court was added by Edmonds permit in 1990 according to the City project file. Detention was waived by the City Engineer on May 1, 1990. Over the years, there has been a persistent flooding problem within the Lake Ballinger drainage basin. Edmonds and Lake Forest Park have joined forces with an extensive program to improve the Lake downstream conditions and to reduce the incidence of flooding along the shoreline. The Snohomish County Soil Survey lists the site soil type as Alderwood Gravely Sandy Loam with 8 to 15 percent slopes and Mukilteo muck around the Lake shore area. The Gravely Sandy Loam corresponds to a type "C" soil with CN's of 81 to 85 depending upon the vegetation and cover conditions. Mukilteo muck is a poorly drained organic soil classified as D without good porosity characteristics. Soil classification is consistent with the wetlands flagged on the north end of the property. Temporary erosion control BMP's will be required to control erosion and potential silt production off the construction area until the site is stabilized and the landscaping is in place. DEVELOPED SITE CONDITIONS The proposed project will tear down the existing house footprint and construct approximately 3,451 SF of regulated new or replaced surface. No other significant changes are anticipated to the site except for installation of a natural gas storage tank and a small detention tank. The slope stability over the long term is the primary consideration with gravity discharge So onsite storm detention will be developed to minimize erosion risk to the downstream. Some Wetland Mitigation techniques may also be proposed to address surface sheetflow from a Sport Court surface located on the waterfront Based upon the analysis provided in this report, detention volume is designed from Table 1 for Small Sites provided by the City of Edmonds. This enclosed table provides standard storage volumes based upon the square footage of impervious to be constructed up to 5,000 SF. 1 J.C. McDonnell Engineering, PC Trieu SFR Drainage Report 5/04/2012 REV.3 DEVELOPMENT AREA DISTRIBUTIONS Site Development Area Distribution Total Property Area = 0.457 Acres, Development Area = 0.286 Acres, Existing Pervious = 0.245 Acres, Proposed Pervious = = 0.217 Acres Existing Impervious Area = 0.232 Acres, Proposed Impervious = 0. 228 Acres According to Figure D the new house is proposed to cover the footprint of the old house. The old house and related pavements were constructed before 1977. Therefore, all existing impervious surfaces repaired or replaced except the new house are "EXEMPT REPLACED". Only previously Pervious Surface that is now covered by New Construction is "REGULATED REPLACED". Based on our quantitative analysis of the drawing provided and adjusted for the AIA ronfline: EXISTING CONDITIONS SA(SF) Non - Regulated Regulated Waived HOUSE 1,360 1,360 ASPH DRIVE 1,963 1,963 CONC D/W & SW 2,500 2,500 SPORT COURT 3,500 9,323 4,463 1,360 3,500 PROPOSED CONDITIONS SA(SF) Non - Regulated Regulated Waived NEW HOUSE 3,175 3,175 NEW CONC DRIVE 564 564 EXIST SW/ASPH COVERED BY NEW CONC DRIVE (58)5 (90) RESURFACED ASPH DRV CONC PAD Removed 1,963 (165) 1,963 (165) EX CONC PATIO NEW CONC. PATIO 1,580 100 1,580 100 SPORT COURT 3,500 3,500 10,569 3,378 3 3,500 J.C. McDonnell Engineering, PC 4 EDMONDS REQUIREMENTS: ' 1. Selected surfaces constructed after 1977 are defined as "regulated" and must be considered for detention. But the Sport Court, which falls into this category ' has A WRITTEN detention waiver since May 1990. It is also located below the 10-year flood elevation making detention physically impossible. 2. Developed IMPERVIOUS Areas over 5,000 SF are categorized as Small Site Category; ' 3. It appears from my discussion with Edmonds staff that the different surfaces identified as "regulated" can be addressed by different techniques to suit the site at hand. 4. Based upon Figure D of the Site Classification Worksheet, this Site is Small Site Category 1. Since "Regulated" surface is <5,000, Detention can be addressed from the City's Table 1. 5. Regulated surface for this project isjfi9+-SF OR 3,700 SF 6. Site soils are GSL to 20" and clay below 20". Therefore, this Site is not suitable for Infiltration. 7. Detention is created for regulated surfaces only. Therefore, storm structures shall be closed with solid lids and shall receive only roof runoff and paved surface runoff from the new impervious surfaces as created. J.C. McDonnell Engineering, PC 5 Trieu SFR Drainage Report 5/04/2012 REV.3 SITE HYDRAULIC ANALYSIS A. DESIGN CRITERIA The City of Edmonds Drainage Ordinance requires that storm water from new impervious surfaces created by development must be detained. The Drainage System Standard Plans further provides that if impervious development is less that the 5,000 sf threshold, a standard pre -tabulated City Drainage table can be used to develop the required storage volume. This site is eligible for the Standard Plans and is considered a Small Site Development under the Edmonds Stormwater Code Supplement. Since the house has been standing since 1948, it is reasonable to conclude that the replaced surfaces are indeed EXEMPT REPLACED by reason of longevity. The Site is a Category 1 Small Site since net impervious excluding the Sport Court (with waiver) is less than 5,000 SF of impervious. Category 1 Small Site Projects are subject to the following Minimum Requirements: ' 1. Small Site Development Requirement #1: Stormwater Site Plan Preparation The Stormwater Site Plan or Drainage Plan is included in the Project Plan Set. 2. Small Site Development Requirement #2: Construction Stormwater Pollution Prevention Plan (SWPPP). The SWPP is included in the Plan set accompanying this report. 3. Small Site Development Requirement #3: Source Control of Pollutants Specific pollution source controls are not required for single family residential sites. General requirements for these sites include the preventing the discharge of pollutants to the City's storm drainage system per City code. 4. Small Site Development Requirement #4: Preservation of Natural Drainage Systems and Outfalls The preservation of the Natural Drainage System and Outfalls on this project assumes the ability to release detained runoff at the historical undeveloped rate as a point discharge or a sheet flow to Lake Ballinger shoreline including the Category 3 Wetland . 5. Small Site Development Requirement #5: Onsite Control of Stormwater Onsite control of stormwater via infiltration is not an achievable alternative for this Site due to the types of soil present, the probability of a high water table on the lower portion of the lot, slope of the ground and the other geotechnical conditions of the site. The design detail of the drainage system on the Trieu property includes a small rooftop detention with gravity pipe and surface water release to sheetflow at the wetland buffer edge. J.C. McDonnell Engineering, PC 6 Trieu SFR Drainage Report 5/04/2012 REV.3 A. DESIGN CRITERIA 6. Small Site Development Requirement #7: Flow Control Flow control has been required by ordinance for regulated surfaces discharging into the downstream lake with complex flooding conditions. Trying to retrofit the sport court is problematic and the requirement has been waived. 7. Small Site Development Requirement #8: Wetland Protection Site does have a requirement for Wetland Protection. The Class 3 Wetland has been addressed in the project Wetland Delineation Report and is relevant to drainage considerations relative to the sport court. The house & sport court drainage provide the water supply to the wetland. Small Site Development Requirement #9: Operation & Maintenance Documentation is required for any structural BMP such as the Detention System. Appropriate pages sited from the King County Drainage Manual are provided in the Appendix. 9. Small Site Development Requirement #11: Financial Liability This requirement for this single family residential site does not apply as the site development will not be constructed within any Critical Area. I J.C. McDonnell Engineering, PC ' Trieu SFR Drainage Report ' 5/04/2012 REV.3 B. DETENTION VOLUME ' Based upon Edmond Handouts and Staff consultation, the following Options have been evaluated for this Project: Selected Option: We have demonstrated on Page 4 that the Site technically meets the definitions for a Small Category 1 site if the existing house surface is properly recognized as EXEMPT ' REPLACED Area. Therefore, it is our opinion that under Option 2, the Site can fulfill the drainage code requirement with a simple Detention System sized from Table 1 as follows: Proposed Impervious area = 3,691 SF(Assume 3,700 based on Edmonds Table 1) Design Detention = 124 CF (928 GAL) ' Table Pipe Equivalents Required= 40 LF of 24" Pipe (126 CF or 939 GAL) 48" SD Manhole Volume = 12.566 CF/Ft* 2 FT = 25.13 CF ' 1 - Type 1-L CB Volume = (28" x 32")/144 Sq.ln. * 2'deep = 12.44 CF SDMH Volume = 25.13 CF CB# 1 TYP 1-L = 12.44 CF 36 LF 24" * 3.1416 CF/FT = 113.1 CF Sub -total = 150.7 CF (1,127 GAL) Outlet Orifice requirements are as follows: For a 24" pipe Diameter = 0.625" orifice (5/8") J.C. McDonnell Engineering, PC 8 Trieu SFR Drainage Report 5/04/2012 REV.3 C. DOWNSTREAM CONDITIONS The Site drains directly to Lake Ballinger. Since the net increase of impervious surface will be approximately 850 SF, the project will not any noticeable effect on the Lake. However, it is understood that there are chronic seasonal flooding issues with this Lake and that they result primarily from urban runoff in the drainage basin. The problems within the Lake Ballinger Drainage Basin are well documented in the Lake Ballinger Fact Sheet (June 2011) as provided in the Appendix. ' J.C. McDonnell Engineering, PC 9 Trieu SFR Drainage Report 5/04/2012 REV.3 D. BUOYANCY ANALYSIS Pipe Cover Calculations Pipe Diameter (D) = 2 feet Pipe Weight* (W) = 24 lb/'ft3 Density of Soil (41,)= 120 Ibfft' Density of Water (/mow) = 62.4 lb/ft3 Pipe Area (A,) = 3.142 ft? Bon}•ancy Force: 4. F * F ., _ 172.0 Ibift Ren^ired Fills D o Area Required to balance FL,1, (a) = Fes" a = 1.434 ft' Satre for Depth fd1: a = A, A. Therefore: A, = d*D A — ID 1 >i(D)2 ' a-A3 2 $ di D A:= 0.4 0: d = 0.50 feet Therefore use 1.0 feet of cover * Pipe weiuht assumes 16 gauge (0.064 inches) steel with Aluminized coating Thickness Max. Weight of 24" Ci4Pt'FT inches WVFT. 0.052 20 0.064 24 0.079 29 Ae �tc-,lcY;10 n The current design calls for cover of 2.0 feet over the pipe. Therefore, the cover will be sufficient to resist pipe buoyancy as long as the pipe is 16-gauge or better or has equivalent weight. J.C. McDonnell Engineering, PC 10 Trieu SFR Drainage Report 5/04/2012 REV.3 ENGINEERING REPORT APPENDICES IJ.C. McDonnell Engineering, PC 11 To Mft LyLE G►ta,'bT MeW EO&i#JEEA434 DEPArAmpi7 of (;ty of EpaoNDS 99 rREE RF WAHER of SiDF Pomij 4-i DETFp7:0n1 FLow 710q LASE S*W#J6rr;a Wky O"AJDS wA q60 U WfA : Igo 0, i Q.I c-w ) PILO PERly OWAI" . DEMz sia c ati 7�y 1 s ►s hQPLit� 7 Pe AkiT Foe ml OAU y" sPoRl (4()f.7 ta�J My PoaPrRTY i k*)D 7a0,34-0 O,) co0vE4C kT"oa ou k,(OL fg41 X AA) o0LP ua ro h'ba p 0 g DEPNfr"iw7 46OV7 rr#i SyS'rfaA u1AideR of TRC giDE DWaA" D'rCWVDo ItoW ou Ky Ahu yA4D NE 70 7"NSi 0010.1 SONS -90(A Ad .. �� gam[ i 3 VL�" T 00 r0i UCR OF T 4i LkU _. L7 i1 &o rLA•'( AQD 764-E 6,UuA)b is 50IF . TAcK CAN DiT,dNs Ca ra Atj 3:MpOS6.*P,4i: 41' -1ATio0 Fo4 A 4TA40 u* tip rS bC- C4,0 TAr wk THt kg: LC caMr vP tv 7gii Yha.D I Mo&p toia -Pi PES . iHhNK yoq JCAy nw" So2 yoia (p0V6E-C*7iom c%-a r ar you u . /wa,'0l, 1,101t Trieu SFR Drainage Report ' 5/04/2012 REV.3 SITE VICINITY AERIAL PHOTO IJ.C. McDonnell Engineering, PC 12 Ballinger Wand 13 Lake Ballinger Q1 i-f Otu 'A IfibROORH, 0 ®, ' -, -��- ,tee �' ,� Nile Golf & Country CILE AM.5pT, -A zip, zz 116 7 N Trieu SFR Drainage Report ' 5/04/2012 REV.3 STORM DRAINAGE SIZING QUALIFICATIONS FIGURES D & E WITH DEFINITIONS I J.C. McDonnell Engineering, PC 13 Figure-D What Qualifies as Replaced Impervious Surface? Is the Impervious Area being removed and replaced with new impermeable surface in the same footprint? Yes No Was the existing impervious area created prior to 7M1977 Yes or prior to the date the parcel was annexed from Snohomish County? No Area is NOT considered REPLACED impervious surface area Refer to Figure E for regulation of New Impervious Surface Areas Area is considered EXEMPT REPLACED impervious surface area Yes Is parcel zoned Yes 01 Does the replaced impervious Single -Family Residential? area replace an existing driveway, walkway or patio in the same footprint AND will it remain the same use after replacement? No No Area is considered REGULATED REPLACED impervious surface area Revised on 421111 E72-SWM Erosion _Conlrol--04.21.II-FINAL Page 8 of 13 ' Figure-E Regulation of NEW Impervious Surface Areas for Determining Site Classification 1 ' Does the site have any existing impervious surface areas that were created on or after No ' after July 7, 19771? 01 Only those areas proposed with the project that are to be Yes converted from pervious IF surfaces (native vegetation, ' etc) to impervious surfaces Have City -approved stormwater controls3 and permeable pavements been applied to all of the existing will be regulated as impervious areas? Yes New Impervious Surface ' For example, does the site have an existing stormwater management system that collects stormwater runoff from all of the existing impervious surfaces? ' No ' Does the existing impervious area Were the existing (not managed by an existing Yes impervious areas Yes stormwater system) exceed constructed prior to the 2,OOOsf? parcel being annexed into ' the City? No No ' Was a waiver from the requirement to install a stormwater management Yes All impervious surface areas created system granted for the existing on or after impervious area? July 7, 19772 plus No All impervious surface areas proposed with the project will be regulated as ' New Impervious Surface Area ' Note: For the purpose of this flowchart, it is assumed that all existing impervious surface will remain after the proposed project is complete. If any existing impervious surface will be demolished for this project, the project may contain a combination of new and replaced impervious surface. See Glossary, p. 10-11. ' Mitigation requirements are based on the total cumulative impervious area created on a project site since July 6, 1977, the effective date of the City's first drainage control ordinance. ' 2 For parcels that were annexed into the City after this date, the date of annexation shall substitute for the effective date of the City's first drainage control ordinance. 3 For annexed parcels, a functioning Snohomish County -approved stormwater management facility can substitute for a City -approved facility. Revised on 4121111 E72-SWM Erosion_Control--04.21.11-FINAL Page 9 of 13 IGlossary I This glossary provides explanations of the terminology used in this handout. The actual definitions can be found in ECDC Chapter 18.30.010 or the Supplement. Impervious Surface: Hard surface area that either prevents or retards the entry of water into the ground as it would occur in natural, undeveloped conditions. Impervious surfaces include, but ai•e not limited to, rooftops, driveways, walkways, concrete, asphalt, and packed earthen materials. Decks will be considered impervious if one or more of the following apply: • Deck is made of "solid" material that does not allow rain water to run through it 0 Deck has "slots" where rainwater can run through but the ground under the deck does not allow the t rainwater to infiltrate into the ground. Open, uncovered retention/detention facilities shall not be considered impervious surfaces for purpose of determining whether the thresholds for application of minimum requirements are exceeded. However, open, uncovered retention/detention facilities shall be considered impervious surfaces for purposes of runoff modeling. Outdoor swimming pools shall be considered impervious surfaces in all situations. ' For the purpose of determining stormwater control requirements, impervious surfaces are divided into four categories: "Non -Regulated", "Exempt Replaced", "Regulated Replaced ", and "New". See explanations below: ' Non -Regulated Impervious Surface: All impervious surface area installed prior to July 7, 1977 or prior to the date the parcel was ' annexed into the City from Snohomish County that will remain unchanged during the site redevelopment. Replaced Impervious Surface: All impervious surface area on the project site existing at the time of application that is proposed to be removed and re-established in the same footprint. This does not include impervious surface removed for the sole purpose of installing utilities or performing maintenance. "Exempt Replaced" - Some of the replaced impervious surface may be "Exempt" if it meets the following condition: On single-family residential parcels only: the replacement of a driveway, walkway, or similar surface in the same footprint in which it was originally installed prior to July 7, 1977 or prior to the date the parcel was annexed into the City from Snohomish County. "Regulated Replaced" - All other replaced impervious surfaces on any parcel that do not qualify as "Exempt" are considered "Regulated." New Impervious Surface: All areas converted from pervious surfaces (native vegetation, etc.) to impervious surfaces and permeable pavements on a project site on or after July 7, 1977 or the date the parcel was annexed 3 Removed refers to the removal of building down to bare soil or subgrade. Roof replacement such as re -shingling, is considered to be a maintenance i' activity and not considered replacing an impervious surface. For others surfaces, such as pavement, "removed" means the removal of concrete (PCC) or asphalt (AC) slabs, driveways, sidewalks or similar surfaces down to bare soil or base course. The pulverization in -place and replacement with a similar wearing course is considered replaced impervious surface. The partial grinding of surfaces for overlay (not down to base soil or base course) is considered to be a maintenance activity. Revised on 4121111 E72-SWM Erosion_Control--04.21.II -FINAL Page 10 of 13 !II 1 into the City from Snohomish County. See Figure-E for exemptions for sites located outside of ' Creek or Lake drainage basins. Land -disturbing Activity: ' Any activity that results in movement of earth, a change in the existing soil cover (both vegetative and non -vegetative), or in the existing soil topography. Land -disturbing activities include but are not limited to clearing, grading, filling, excavation, and compaction of soils associated with structure ' stabilization and road construction. Pervious Surface: Any surface that allows the entry of water into the ground as it would occur in nature. 1 1 ' Revised on 42MI E72-SWM Erosion_Control--04.21.11-FINAL. Page 11 of 13 1 • i Trieu SFR Drainage Report i' 5/04/2012 REV.3 SITE CLASSIFICATION WORKSHEET IJ.C. McDonnell Engineering, PC 14 City of Edmonds Of ED&O� Site Classification Worksheet - Page 1 of 2 /"C. 1a9� The project's Site Classification will dictate the specific stormwater management requirements applicable to your site. Completing this worksheet will help determine the amount of regulated impervious surface and whether your project falls into the classification of a Small Site (Category 1 or Category 2), or a Minor Site. Please reference the Glossary (DD. 10-11), Figures D and E (pp. 8-9) and Examples (pp 12-13) to assist with completion of this worksheet. 1) Is Permeable Pavement' Proposed For Use on this Site? ❑ Yes ❑ No Refer to Stormwater Supplement Chapter 5.1 If YES, the subject area is to be considered impervious for initial site classification purposes. Include total permeable pavement area in the calculation of Non -Regulated, Replaced and/or New impervious surface areas in the table below. 2) Determine the Amount and Type of Existing & Proposed Impervious Surface for the Site Refer to Stormwater Supplement Chapter 2 and Fig. C Line 1: Identify the Non -Regulated Impervious Surface Area. Line 2: Identify the Replaced Impervious Surface Area, dividing the total between Exempt and Regulated; either or both may be zero. Note: For project classification purposes, Replaced Impervious may only be considered exempt under certain conditions. Refer to the Glossary and Figure D. Line 3: Identify the New Impervious Surface Area for your project. All impervious areas created post -July 7, 1977 or after the date of annexation into the City are regulated & should be included in this total unless they can be categorized separately as a Replaced -Regulated area. Line 4: Enter the sum of the total Replaced -Regulated plus the total New impervious areas. Line 5: Identify the total area currently mitigated by an existing city -approved stormwater management system. Line 6: Enter the sum of the value in Line 4 less the value in Line 5 to identify the total Regulated area in which stormwater controls have not yet been applied. Line 7: Identify the total area proposed to be mitigated through the use of Low Impact Development Techniques. Line 8: Identify the total area proposed to be mitigated through conventional Stormwater Management Techniques. ** Provide a copy of the following table on the drainage plan sheet for the proposed project ** Line Type Area (square feet) 1. Non -Regulated 69 78 5,F Exempt Regulated 2. Replaced y 8 sr, Z1 1 71SE 3. 4. _ -^ New (Post 1977) 4 4 4 4 4 4 4 Total Regulated Impervious Area Mitigation required if in excess of 2000s 66 S �' 7 5. 6. Total Area Mitigated by Existing Stormwater Management System(s) Regulated Area Not Yet Mitigated = 3 7 7. Area Proposed to be Mitigated by Low Impact Development Techniques _ 8. Area Proposed to be Mitigated through Conventional SWM Techniques t (e.g. porous asphalt, porous concrete, paver blocks, concrete open celled paving grids, or plastic lattices filled with turf or stone) I Revised on 4121111 E72-SWM_Erosion_Control-Draft-04.21.I ]-FINAL Page 5 of 13 City of Edmonds �Y°f D-0� Site Classification Worksheet`s` Page 2 of 2 3) Determine the Total Area of Land Disturbing Activity b,� sf Refer to Stormwater Supplement Chapter 8 4) Determine the Quantity of Grading, Fill and/or Excavation C cy 5) Will the project convert 3/4 Acre or More of Native Vegetation to Lawn or ❑ yes NrNo Landscaped Area? 6) Identify the Watershed the Existing Site Runoff Discharges to Refer to Stormwater Supplement Chapter 2.3 Based on Site Location and Watershed Map — Figure-C. Check all that apply. A. ❑ Direct Discharge B. VCreek or Lake Basin o Edmonds Way Basin o Puget Sound Basin o Puget Sound Piped Basin DETERMINE PROJECT CLASSIFICATION USING THE INFORMATION ABOVE AND THE PROJECT CLASSIFICATION CHART (Figure B, pg 4) ❑ Small Site - Category 1 YSmall Site - Category 2 []Minor Site Stormwater Supplement Stormwater Supplement Stormwater Supplement Chapter 5 Chapter S : ' , Chapter 6 Revised on 4121111 E72-SWM_Erosion_Control-Draft-04.21.11-FINAL Page 6 of 13 ' Trieu SFR Drainage Report ' 5/04/2012 REV.3 DETENTION SIZE TABLE IJ.C. McDonnell Engineering, PC 15 Table 1 Detention Pipe Look -Up Table Category 1 Small Site Projects Contributing New Plus Replaced Impervious Surface Area (sf) Length of Pi ft For Given Inside Diameter 18-inch 24-inch 30-inch 36-inch 2,000 41 22 15 11 2,500 49 30 18 12 3,000 61 33 23 16 3,500 74 38 24 17 4,000 91 45 29 20 4,500 95 1 49 32 23 5,000 112 1 56 35 25 sf — square feet Orifice Size: 0.5 (1/2) inch diameter = 0.75 (3/4) inch diameter = 0.625 (5/8) inch diameter = 0.875 (7/8) inch diameter - Outlet pipes (including in the flow control structure) must be 8 in diameter for 2,000 to 4,000 square feet of new plus replaced impervious surface area. - Outlet pipes (including in the flow control structure) must 10 in diameter for greater than 4,000 square feet of new plus replaced impervious surface area. Note: Multiple pipes in parallel connected together (manifolded) can be used to meet length requirements, if site has constraints. Table 2 Approved Detention Pipe Material and Catch Basin/Manhole Structure Sizing Detention Pipe Inside Diameter WDOT (inches) Detention Pipe Material Catch Basin/Manhole 18 All types in list below table Type I Catch basin 24 All types in list below table Type 2, 48-inch diameter manhole 30 All Metal & RPP Type 2, 48-inch diameter manhole All Concrete & CPEP Type 2, 54-inch diameter manhole PVCP Type 2, 60-inch diameter manhole 36 Metal & RPP [All Type 2, 54-inch diameter manhole concrete, CPEP, & PVCP Ty2e 2, 60-inch diameter manhole WDOT - Washington Department of Transportation List of Approved Pine Materials for Detention Metal: ACSP - Aluminized Corrugated Steel Pipe (Type 2 meets AASTO designations M274 and M36) ASRP - Aluminum Spiral Ribbed Pipe (16 gauge or better) CAP -Corrugated Aluminum Pipe (16 gauge or better) DIP - Ductile Iron Pipe (Class 50 or better) Concrete: PCP - Plain Concrete pipe RCP - Reinforced Concrete Pipe -2- Plastic: PVCP - Polyvinyl Chloride Pipe (SDR 35 or better) CPEP - Corrugated Polyethylene Pipe (smooth interior wall, or N-120 pipe) RPP- Ribbed Polyvinylchloride Pi Trieu SFR Drainage Report ' 5/04/2012 REV.3 OPERATION & MAINTENANCE TECHNIQUES I J.C. McDonnell Engineering, PC 16 KING COUNTY, WASHINGTON, SURFACE WATER DESIGN MANUAL KING COUNTY, WASBINGTON SURFACE WATER DESIGN MANUAL APPENDIX A MAINTENANCE REQUIREMENTS FOR PRIVATELY MAINTAINED DRAINAGE FACILITIES Section No. Subiect 2 pantiv Infiltration 3 Closed Detention Systems 4 Control Structure/ Flow Restrictor 5 Catch Basins �E1eles 10 Conveyance Systems A�•B'wfmWe �elee�ells s mwwws �}4ii4�etieh4Reside 9/1/98. APPENDIX A MAINTENANCE STANDARDS FOR PRIVATELY MAINTAINED DRAINAGE FACILITIES NO.2 - INFILTRATION Maintenance Defect Conditions When Maintenance Results Expected When Component Is Needed Maintenance Is Performed f General Trash & Debris See *Ponds' Standard No. 1 See 'Ponds' Standard No. 1 Poisonous Vegetation See 'Ponds' Standard No. 1 See "Ponds' Standard No. 1 Pollution See 'Ponds' Standard No. 1 See 'Ponds' Standard No. 1 Unmowed Grass/ See 'Ponds* Standard No. 1 See 'Ponds' Standard No. 1 Ground Cover Rodent Holes See "Ponds' Standard No. 1 See "Ponds* Standard No. 1 Insects See 'Ponds' Standard No.1 See 'Ponds' Standard No. 1 Storage Area Sediment A percolation test pit or test of facility indicates Sediment is removed and/or facility. Sheet Cover (If Applicable) Sump Filled with Sediment and Debris (If Applicable) Filter Bags Filled with Sediment and Debris facility is only working at 90% of its designed capabilities. If two inches or more sediment is present, remove. Sheet cover is visible and has more that three 1/4-inch holes in it. is cleaned so that infiltration system works according to design. Sheet cover repaired or replaced. Clean out sump to design depth. Replace filter bag or redesign system. Rock Filters Sediment and Debris By visual inspection, little or no water flows Replace gravel in rock filter. through filter during heavy rain storms. Side Slopes of Pond Erosion See 'Ponds' Standard No.1 See 'Ponds' Standard No. 1 Emergency Rock Missing See 'Ponds' Standard No. 1 Overflow Spillway Settling Ponds and Sediment Remove when 6' or more. Vaults Note: Sediment accumulation of more than .25 inches'per year may indicate excessive erosion is occurring upstream of the facility or that conveyance systems are not being properly maintained. The contributing drainage area should be checked for erosion problems or inadequate maintenance of conveyance systems if excessive sedimentation is noted in in infiltration facility. Check twice a year during first 2 years of operation; once a year thereafter. Clean manholes/catch basins, repair damaged inlets/outlets, clean trash racks. Any sediment and debris filling vault to 10% of depth from sump bottom to bottom of outlet pipe or obstructing flow into the connector pipe. Sediment and debris fill bag more than 1/2 full. 9/1/98 1998 Surface Water Design Manual A-2 APPENDIX A MAINTENANCE STANDARDS FOR PRIVATELY MAINTAINED DRAINAGE FACILITIES NO.3 - CLOSED DETENTION SYSTEMS (PIPES/TANKS) i Maintenance Defect Conditions When Maintenance is Needed Results Expected When 1 Component Maintenance is Performed Storage Area Plugged Air Vents One-half of the cross section of a vent is blocked at Vents free of debris and any point with debris and sediment sediment Debris and Accumulated sediment depth exceeds 10% of the All sediment and debris Sediment diameter of the storage area for 1h length of storage removed from storage area. vault or any point depth exceeds 15% of diameter. Example: 72-inch storage tank would require cleaning when sediment reaches depth of 7 inches for more than'h length of tank. Joints Between Any crack allowing material to be transported into All joint between tank /pipe Tank/Pipe Section facility sections are sealed Tank Pipe Bent Any part of tank/pipe is bent out of shape more than Tank/ pipe repaired or replaced Out of Shape 10% of its design shape to design. Manhole Cover Not in Place Cover is missing or only partially in place. Any open Manhole is closed. manhole requires maintenance. Locking Mechanism cannot be opened by one maintenance Mechanism opens with proper Mechanism Not person with proper tools. Bolts into frame have less tools. Working than'h inch of thread (may not apply to self-locking lids.) Cover Difficult to One maintenance person cannot remove lid after Cover can be removed and Remove applying 80lbs of lift. Intent is to keep cover from reinstalled by one maintenance sealing off access to maintenance. person. Catch Basins Ladder Rungs King County Safety Office and/or maintenance person Ladder meets design standards Unsafe judges that ladder is unsafe due to missing rungs, allows maintenance person safe misalignment, rust, or cracks. access. See "Catch Basins" Standards No. 5 See "Catch Basins" Standards No. 5 1998 Surface Water Design Manual 9/1/98 A-3 APPENDIX A MAINTENANCE STANDARDS FOR PRIVATELY MAINTAINED DRAINAGE FACILITIES NO.4 - CONTROL STRUCTUREIFLOW RESTRICTOR ' Maintenance Defect Condition When Maintenance is Needed Results Expected When Component Maintenance is Performed General Trash and Debris Distance between debris build-up and bottom of All trash and debris removed. ' (Includes Sediment) orifice plate is less than 1-1/2 feet. Structural Damage Structure is not securely attached to manhole wall Structure securely attached to and outlet pipe structure should support at least wall and outlet pipe. 1,000 Ibs of up or down pressure. Structure is not in upright position (allow up to Structure in correct position. 10% from plumb). ' Connections to outlet pipe are not watertight and Connections to outlet pipe are show signs of rust. water tight; structure repaired or replaced and works as designed. ' Any holes —other than designed holes —in the Structure has no holes other structure. than designed holes. Cleanout Gate Damaged or Missing Cleanout gate is not watertight or is missing. Gate is watertight and works as ' designed. Gate cannot be moved up and down by one Gate moves up and down easily maintenance person. and is watertight. Chain leading to gate is missing or damaged. Chain is in place and works as designed. ' Gate is rusted over 50% of its surface area. Gate is repaired or replaced to meet design standards.. Orifice Plate Damaged or Missing Control device is not working properly due to Plate is in place and works as ' missing, out of place, or bent orifice plate. designed. Obstructions Any trash, debris, sediment, or vegetation Plate is free of all obstructions ' blocking the plate. and works as designed. Overflow Pipe Obstructions Any trash or debris blocking (or having the Pipe is free of all obstructions potential of blocking) the overflow pipe. and works as designed. Manhole See "Closed Detention Systems" Standards No. 3 See "Closed Detention Systems' Standards No. 3 ' Catch Basin See "Catch Basins" Standards No. 5 See 'Catch Basins" Standards No. 5 9/1/98 1998 Surface Water Design Manual A-4 APPENDIX A MAINTENANCE STANDARDS FOR PRIVATELY MAINTAINED DRAINAGE FACILMES NO.5 - CATCH BASINS - Maintenance Defect Conditions When Maintenance is Needed Results Expected When Component Maintenance is performed ' General Trash & Debris Trash or debris of more than 1/2 cubic foot which is No Trash or debris located (Includes Sediment) located immediately in front of the catch basin immediately in front of catch opening or is blocking capacity of the basin by basin opening. more than 10% Trash or debris (in the basin) that exceeds 1/3 the No trash or debris in the catch depth from the bottom of basin to invert the lowest basin. pipe into or out of the basin. Trash or debris in any inlet or outlet pipe blocking Inlet and outlet pipes free of more than 113 of its height. trash or debris. Dead animals or vegetation that could generate No dead animals or vegetation odors that could cause complaints or dangerous present within the catch basin. gases (e.g., methane). Deposits of garbage exceeding 1 cubic foot in No condition present which volume would attract or support the breeding of insects or rodents. Structure Damage to Comer of frame extends more than 3/4 inch past Frame is even with curb. Frame and/or Top Slab curb face into the street (If applicable). Top slab has holes larger than 2 square inches or Top slab is free of holes and cracks wider than 1/4 inch (intent is to make sure cracks. all material is running into basin). Frame not sitting flush on top slab, i.e., separation Frame is sitting flush on top of more than 3/4 inch of the frame from the top slab. slab. Cracks in Basin Walls/ Cracks wider than 1/2 inch and longer than 3 feet, Basin replaced or repaired to Bottom any evidence of soil particles entering catch basin design standards. through cracks, or maintenance person judges that structure is unsound. Cracks wider than 1/2 inch and longer than 1 foot No cracks more than 1/4 inch at the joint of any inlet/ outlet pipe or any evidence wide at the joint of inlet/outlet of soil particles entering catch basin through pipe. cracks. Sediment/ Basin has settled more than 1 inch or has rotated Basin replaced or repaired to Misalignment more than 2 inches out of alignment. .design standards. 1998 Surface Water Design Manual 9/1/98 ' A-5 I APPENDIX A MAINTENANCE STANDARDS FOR PRIVATELY MAINTAINED DRAINAGE FACILITIES, NO.5 - CATCH BASINS (CONTINUED) ' Maintenance Defect Conditions When Maintenance is Needed Results Expected When Component Maintenance is performed Fire Hazard Presence of chemicals such as natural gas, oil and No flammable chemicals ' gasoline. present. Vegetation Vegetation growing across and blocking more than No vegetation blocking opening 10% of the basin opening. to basin. ' Vegetation growing in inlet/outlet pipe joints that is No vegetation or root growth more than six inches tall and less than six inches present. apart. ' Pollution Nonflammable chemicals of more than 1/2 cubic foot No pollution present other than per three feet of basin length. surface film. Catch Basin Cover Cover Not in Place' Cover is missing or only partially in place. Any open Catch basin cover is closed catch basin requires maintenance. Locking Mechanism Mechanism cannot be opened by on maintenance Mechanism opens with proper Not Working person with proper tools. Bolts into frame have less tools. ' than 1 /2 inch of thread. Cover Difficult to One maintenance person cannot remove lid after Cover can be removed by one Remove applying 80 lbs. of lift; intent is keep cover from maintenance person. ' sealing off access to maintenance. Ladder Ladder Rungs Ladder is unsafe due to missing rungs, misalignment, Ladder meets design standards Unsafe rust, cracks, or sharp edges. and allows maintenance person ' safe access. Metal Grates Grate with opening wider than 7/8 inch. Grate opening meets design (If Applicable) standards. Trash and Debris Trash and debris that is blocking more than 20% of Grate free of trash and debris. ' grate surface. Damaged or Grate missing or broken member(s) of the grate. Grate is in place and meets ' Missing. design standards. NO.6 DEBRIS BARRIERS (E.G., TRASH RACKS) ' Maintenance Defect Condition When Maintenance is Needed Results Expected When. Components Maintenance is Performed. ' General Trash and Debris Trash or debris that is plugging more than 20% of Barrier clear to receive capacity the openings in the barrier. flow. Metal Damaged/ Missing Bars are bent out of shape more than 3 inches. Bars in place with no bends more ' Bars. than 3/4 inch. Bars are missing or entire barrier missing. Bars in place according to design. ' Bars are loose and rust is causing 50%deterioration Repair or replace barrier to to any part of barrier. design standards. 1998 Surface Water Design Manual A-6 APPENDIX A MAINTENANCE STANDARDS FOR PRIVATELY MAINTAINED DRAINAGE FACILITIES NO.10 - CONVEYANCE SYSTEMS (PIPES & DITCHES) Maintenance Defect Conditions When Maintenance is Needed Results Expected When Component Maintenance is Performed I Pipes Sediment & Debris Accumulated sediment that exceeds 20% of the Pipe cleaned of all sediment diameter of the pipe. and debris. Vegetation Vegetation that reduces free movement of water All vegetation removed so water through pipes. flows freely through pipes. ' Damaged Protective coating is damaged; rust is causing Pipe repaired or replaced. more than 50% deterioration to any part of pipe. Any dent that decreases the cross section area of Pipe repaired or replaced. pipe by more than 200%. Open Ditches Trash & Debris Trash and debris exceeds 1 cubic foot per 1,000 Trash and debris cleared from ' square feet of ditch and slopes. ditches. Sediment Accumulated sediment that exceeds 20 % of the Ditch cleaned/ flushed of all design depth. sediment and debris so that it matches design. ' Vegetation Vegetation that reduces free movement of water Water -flows freely through through ditches. ditches. Erosion Damage to See "Ponds" Standard No. 1 See "Ponds" Standard No. 1 Slopes Rock Lining Out of Maintenance person can see native soil beneath Replace rocks to design Place or Missing (If the rock lining. standards. ' Applicable). ' Catch Basins See "Catch Basins: Standard No. 5 See "Catch Basins" Standard No. 5 ' ( Debris Barriers See "Debris Barriers" Standard No.6 See "Debris Barriers" Standard (e.g., Trash Rack) No. 6 ' NO.11 -GROUNDS (LANDSCAPING) Maintenance Defect Conditions When Maintenance is Needed Results Expected When Component Maintenance is Performed ' General Weeds Weeds growing in more than 20% of the landscaped Weeds present in less than 5% (Nonpoisonous) area (trees and shrubs only). of the landscaped area. Safety Hazard Any presence of poison ivy or other poisonous No poisonous vegetation ' vegetation. present in landscaped area. Trash or Litter Paper, cans, bottles, totaling more than 1 cubic foot Area clear of litter. within a landscaped area (trees and shrubs only) of ' 1,000 square feet. Trees and Shrubs Damaged Limbs or parts of trees or shrubs that are split or Trees and shrubs with less than broken which affect more than 25% of the total 5% of total foliage with split or i' foliage of the tree or shrub. broken limbs. Trees or shrubs that have been blown down or Tree or shrub in place free of knocked over. injury. ' Trees or shrubs which are not adequately supported Tree or shrub in place and or are leaning over, causing exposure of the roots. adequately supported; remove any dead or diseased trees. 1998 Surface Water Design Manual 9/1/98 1 A-9 ' Trieu SFR Drainage Report ' 1 /20/2012 SITE DOWNSTREAM CONDITIONS REPORT IJ.C. McDonnell Engineering, PC Lake Ballinger Fact Sheet Revision Date: June 15, 2011 As a result of flooding events in August 2004, the City of Mountlake Terrace was contacted by several Edmonds residents on Lake Ballinger concerned about the high water level on the lake. In an effort to address this issue and others that were raised during discussions, the following "Lake Ballinger Fact Sheet" along with a chronological list of developments was prepared and distributed to lake residents. Information regarding the level of the lake, storm water inflow to the lake, water quality of the lake, and the ongoing efforts of the City of Mountlake Terrace, the City of Edmonds, and several other adjacent agencies to address these issues is included in this fact sheet. The fact sheet is periodically updated as new information becomes available. Lake Ballineer Fact Sheet: Watershed Area: Shoreline 22%, Snohomish County 9%, Mountlake Terrace 23%, Edmonds 25%, Lynnwood 21% Size: 107 acres (including the island) — 72 acres in Mountlake Terrace and 35 acres in Edmonds Depth: Deepest depth is approximately 35 feet Private Ownership: Three lots in Mountlake Terrace, 49 in Edmonds, Nile Temple Property Public Ownership: Lake Ballinger Golf Course, Lake Ballinger Swimming Beach and Dock Drainage Basins: Hall Creek — 66 percent of inflow Echo Lake, Aurora Village — 16 percent of inflow Non-specific areas adjacent to the lake — 18 percent of inflow Lake Ballinger Events: - 1942 - Lake Level Established by Court Order o Authorized installation of a lake outflow weir on McAleer Creek o Authorized formation of a tax district to pay for maintenance and operation of the weir - 1954 - Mountlake Terrace Incorporates - Mid 1960's - Nile Temple filled in an area north of the existing creek site -and raised the roadbed area near the first culvert downstream on McAleer Creek effectively creating a higher roadbed and effectively raising the high overflow level of the lake during large storm events. Prior to this work, high water levels that exceeded the height of the weir flowed around the roadbed and culvert at a lower high overflow elevation. Lake Ballinger Fact Sheet June 15, 2011 Page 2 - Early 1970's - Staff notices and takes reports from residents about Lake Ballinger water quality issues. - 1972 - Department of Ecology (DOE) study finds that Lake Ballinger has the poorest water quality of 34 lakes surveyed in the Puget Sound area. - 1973 - First Lake Ballinger Report compiled by consultant to begin background assessment of water quality. - 1974 - Second Lake Ballinger Report prepared as part of the Lakeview Drive Road Construction Project indicating ongoing nutrient issues with the lake causing algae blooms. - Mid 1970's - Resident Bob Boye begins to release Chinook fry to the lake and helps to develop the Salmon in the Classroom program with the Department of Fish and Wildlife. - 1976 - Interlocal agreement with Edmonds, King County and Mountlake Terrace to study Lake Ballinger in more detail through King County Metro project. - 1977 - King County Metro study published with recommendations for improvements to Lake Ballinger. - 1978 - Mountlake Terrace receives a grant from DOE and EPA to improve water quality. - 1979 - Mountlake Terrace contracts with Kramer Chin & Mayo to design water quality improvements. 1980 - Construction begins on water quality improvements to Hall Creek (bank restoration and two instream sedimentation ponds) and McAleer Creek (bank improvements, removal of accumulated sediment in creek channel and construction of a new weir at the original site on Nile Temple property). - 1982 - Mountlake Terrace coordinates the readjudication process to reset the level of Lake Ballinger to reduce flooding and drainage impacts due to storm events and to allow operation of ' new water quality piping system in the lake. 1982 - Work is completed on installation of a Hypolimnetic Injection System to transport oxygen rich water from Hall Creek to the bottom of the lake and remove oxygen -depleted water from the bottom of the lake to an outlet at the weir on McAleer Creek. ' - Mid 1980's - Several pump failures at the Ballinger Sanitary Sewer Pump Station result in Lake Ballinger Fact Sheet ' June 15, 2011 Page 3 ' sewer spills to McAleer Creek and Lake Ballinger. - 1985 - Mountlake Terrace hires a water quality specialist, sets up a water quality lab and begins ' monitoring efforts in the Lake Ballinger Basin. - 1987 The State of Washington begins efforts to coordinate water quality and stormwater ' runoff issues in Puget Sound through stormwater management and resource protection by forming a Puget Sound Water Quality Authority. ' - 1987 - Mountlake Terrace adopts a new stormwater code for development and water quality control. ' - 1991 - Mountlake Terrace implements a project to treat the lake with alum to help reduce nutrient levels through an Ecology Water Quality grant. ' - 1991 - New sanitary sewer pump station installed by King County Metro to replace the old City operated Lake Ballinger Pump Station. ' - 1992 - Third Lake Ballinger Water quality report published which indicates that the water quality improvements installed in the 1980's are continuing to provide interim treatment and protection, but that continued basin -wide stormwater management is needed to prevent ' additional degradation of the lake. - 1993 - Water quality specialist leaves city employment along with the lab technician — water ' quality lab is dismantled - water quality program is reduced to minimum level for necessary maintenance and complaint response. t - 1993 - Total Maximum Daily Load (TMDL) listing for excess phosphorous is developed by Ecology as part of the water quality plan published in the 1985 final grant report for Lake Ballinger by Kramer, Chin, and Mayo. ' - 1995 - Nile Temple Golf Course remodel making an 18-hole course from the original nine -hole course. ' - 1996 - State forms the Puget Sound Water Quality Action Team within the Puget Sound Water Quality Authority to review and update management efforts to protect and restore the Sound, ' and to coordinate with local agencies. - 1996-7 New Years Day - Major snow storm and subsequent rainfall, raises lake level to an ' elevation of 283.5 feet, six feet above normal winter elevation — several structures on the south Lake Ballinger Fact Sheet ' June 15, 2011 Page 4 side of the lake are flooded — the sanitary sewer trunk line on the west side of the lake overflows into the water over a period of several days. ' - Spring 1997 - City of Mountlake Terrace and City of Edmonds staff meet with impacted homeowners to discuss possible mitigation measures — the meeting took place at the home of Mr. John Greenwold — no conclusions were reached as remedies would all likely involve the ' Nile Temple - Nile goes on record as opposing the lowering of the lake and would require compensation for any disrupted play as a result of any work accomplished on Nile property related to the lake level. ' - 1999 - Ballinger Recreation, Inc completes Lake Ballinger Golf Course rehabilitation. - 1999 October - Chinook Salmon are listed as a threatened species in several locations in Washington State, including Puget Sound and Lake Washington. - 2000 January - Mountlake Terrace forms a separate Storm Water Utility separate from the Water and Sewer Utilities to provide dedicated funding to storm water management activities. - 2000 - Puget Sound Water Quality Management Plan encourages adoption of more stringent regional stormwater requirements. - 2001 May - City adopts the 2001 DOE Stormwater Management Manual for Western Washington for all new development proposals. - 2003 October - Lake Ballinger resident Bob Boye reports the presence of a 15-pound Chinook salmon near his neighbors dock — Bob believes this the first returning salmon he has seen from one of his hatchery releases. - 2004 August - Two major summer storms cause localized flooding and a higher than normal lake level. - 2005 January — Meeting between City of Mountlake Terrace, City of Edmonds and the Lake Ballinger Community Association. Periodic meetings are held between staff members of each City and the Lake Ballinger Community Association. - 2005 September - City of Mountlake Terrace enters into an agreement with Tyrone and Carole Hardy to run the Ballinger Lakes Golf Course. - 2005 Fall - Heavy rainfall results in a higher than normal lake level. Lake Ballinger Fact Sheet ' June 15, 2011 Page 5 ' - 2006 January - Heavy rainfall again results in a higher than normal lake level — 279.4. - 2006 December — Heavy rainfall results in lake level of 279.5. ' - 2007 June — Representatives from Mountlake Terrace, Lynnwood, Shoreline, Edmonds, Lake Forest Park and the Lake Ballinger Community Association meet to discuss water quantity and t water quality issues in the Lake Ballinger Basin. Each jurisdiction and the Lake Ballinger Community Association agree to pursue a watershed plan. ' - 2007 November — Testing is performed for the first time to identify specific species of algae present in a bloom on the lake. Toxic blue-green algae are present but the toxin level is below the level of concern according to the Snohomish Health District. - 2007 December - Heavy rainfall is experienced in the Lake Ballinger Basin. 5.6 inches of rain falls in a 36-hour period between 6:00 am Sunday morning December 2❑d and 6:00 pm Monday December 31d at the Mountlake Terrace Public Works Facility. Streets are flooded in many low-lying areas of the basin with multiple street closures. At least three homes are flooded on Lake Ballinger and six properties are flooded on Hall Creek between Lake Ballinger and 220`h St. SW. Lake Ballinger Reaches an elevation of 280.6, the second highest level since recording began in 1981. Sewage flows into the lake from at least one location on the Edmonds side and from two locations on Hall Creek in Mountlake Terrace. - 2008 March — State Legislature authorizes $200,000 to study surface water and ground water impacts to the level of Lake Ballinger. - 2008 August — Lake Ballinger/McAleer Creek Forum Interlocal Agreement prepared to develop a Strategic Action Plan for the watershed. - 2008 November — Lake Level Study by Edmonds, Mountlake Terrace and Shoreline completed and presented to Lake Ballinger/McAleer Creek Forum. - 2008 November — A public meeting is held at the Ballinger Lakes Golf Course for input into the development of the Strategic Action Plan. - 2009 May — A second public meeting is held at the Ballinger Lakes Golf Course for final input into the Strategic Action Plan. - 2009 July — The Strategic Action Plan is accepted by the Forum. - 2010 January —A Capital Improvement Program is adopted by the Forum. I Lake Ballinger Fact Sheet June 15, 2011 Page 6 ' - 2010 September — A renewed interlocal agreement is implemented with Edmonds, Lake Forest Park, Mountlake Terrace and Snohomish County participating. - 2011 January — The Johnston Group is hired by the Forum to lobby for federal and state funding to assist with implementation of the Capital Improvement Program developed from the Strategic Action Plan. Issues raised by Lake Ballinger residents (at the January 2005 meeting): t1. Taxing district for weir maintenance. The 1942 order and the 1982 adjudication provided a funding mechanism for the state and subsequently the City to maintain and operate the weir. The yearly assessment provides funds for the City to inspect, operate and maintain the weir and the McAleer Creek channel from the lake to the I-5 culvert crossing. The assessment is based on actual time spent by City staff the previous year to inspect and remove debris from the weir ' on McAleer Creek and to raise and lower the lake level. This assessment is collected and held by Snohomish County until a statement of yearly costs is received from the City. Upon release by the County, these funds are placed into the City Stormwater Utility Fund to reimburse actual ' expenses. 2. Level of lake. The 1942 Superior Court order set the minimum level of Lake Ballinger at ' 276.5 feet, with a maximum of 278.5 feet. The Director of Hydraulics for the State of Washington was identified to control and maintain the weir. The 1982 adjudication changed this level slightly and approved a new weir structure to replace the failing structure installed in ' the 1940's. The lake levels adhered to since 1982 are as follows: a. April 1 to June 15 277.0 ' b. June 15 to September 15 277.5 c. September 15 to October 31 277.0 d. October 31 to April 1 276.8 ' The court order also limits the discharge from the lake to no more than 60 cubic feet per second. This is slightly less than the maximum amount of water that can flow through the ' culverts on Nile Temple property and under Interstate 5. The maximum level of the lake is also not to exceed 278.5 more than once in any five-year period. ' 3. Nuisance Animals. The two major nuisance animals impacting Lake Ballinger are beavers and geese. ' a. Beavers. Beaver naturally make their way up McAleer Creek from Lake Washington Lake Ballinger Fact Sheet June 15, 2011 Page 7 and have, on occasion, damned McAleer Creek and created a nuisance for property owners on the lake by destroying small trees and shrubs. The City has a program in place to remove and relocate nuisance animals as needed. b. Geese. Geese have been present on the lake in large numbers since the early 1980's. As I am sure all the residents are aware of, geese droppings have been a major inconvenience on grass and lawns and are the major source of high fecal coliform counts in the past at the Lake Ballinger Swimming Beach. A variety of control methods have been used with limited success. The City currently has a contract with the Washington State Department of Agriculture to perform egg addling where nests can be found on City property around the lake. This procedure inhibits hatching by application of an oil film to the eggs. Combined with efforts of property owners around the lake to harass offending birds, the number of geese using the lake on a permanent basis appears to have dropped significantly. 4. Water Quality. a. General Water Quality. Lake Ballinger is an urban lake with urban runoff problems. Petroleum products from road runoff, nutrients from fertilizers and high fecal coliform levels from domestic pets, animals and birds are the biggest contributors to the water quality problems in Lake Ballinger. The most cost effective method of pollution and nutrient control is at the source. The City has a comprehensive stormwater program that helps to address water quality through street sweeping, illicit discharge identification, spill response and stormwater facility inspections for commercial and multifamily sites. b. Algae Blooms. Algae blooms are caused by an excess of nutrients in the lake. Algae proliferate, die, and sink to the bottom of the lake. The process of decomposition removes oxygen from the lower reaches of the lake and makes it difficult for aquatic organisms to survive. The southern end of Hood Canal has been identified with the same lack of oxygen, primarily due to the nutrient issues from development runoff and failing septic tanks in the area. The Hypolimnetic piping system serves to help counter this effect by raising the oxygen content of water at the bottom of the lake. Mountlake Terrace participates in the Department of Ecology blue/green algae identification program. To date, blue/green algae has not been identified at a concentration that is harmful to people or pets. c. Swimmer's Itch. The Snohomish Health District monitors this issue and will post public swimming beaches in the event of an outbreak. 5. Water Quantity. The issue of the amount of water reaching Lake Ballinger during storm events has been the overriding issue of concern with resident in recent years. While all jurisdictions in the Lake Lake Ballinger Fact Sheet ' June 15, 2011 Page 8 t Ballinger Basin have implemented more stringent stormwater detention standards in recent years, new development continues to add additional impervious surface area to the drainage basin every year. As a result of rainfall events that are occurring with increased intensity ' and duration, residents on Lake Ballinger can expect to see rapidly rising lake levels during future storm events. ' Public education and information is perhaps the most important element of the City of Mountlake Terrace stormwater program. Contacts with residents and sharing of information through fact sheets like this document are very much a part of the solution to water quality and quantity issues on the lake. ' Residents have a voice in this effort and can be very effective. This fact sheet and chronology of events regarding Lake Ballinger is intended to help to educate and inform residents about storm water issues related to Lake Ballinger. If you have any questions or have additional information to add to this document, please feel free to contact Stormwater Program Manager Mike Shaw at Mountlake Terrace Public Works, 425-670-8264 ext. 5105. ' pwAstormwater\ ake BaHinger\ ake Ballinger Fact Sheet 6_15_2011 ED MCCARTHY, P.E., PS Hydrology • Hydraulics • Engineering February 13, 2012 9957 171 AVENUE SE RENTON, WA 98059 (425) 271-5734 Mr. Frank Trieu APPROVED BY PLANNING c/o Mel Maertz 3 / Z 6 // Z M2 Architects Re: 7109 Lake Ballinger Way — Tax Parcel 00488800800700 Lake Ballinger Flood Hazard Assessment Dear Mr. Trieu: I've completed a flood hazard assessment for your property located at 7109 Lake Ballinger Way in Edmonds. This assessment meets the requirements of Edmonds City Code 23.70.020 for special studies and reports. The subject property is on the south shore of Lake Ballinger and is in an area mapped by FEMA as a Zone A flood hazard area (Attachment A). Zone A areas have a one percent annual chance of flooding. Because Zone A flood areas do not have a FEMA-approved flood study, no depths or base flood elevations are shown within these zones on the FEMA map. I understand that the existing single-family structure on the subject property will be replaced with a new one. The finished floor elevation of the existing structure on the site is at elevation 288.29 feet NAVD 88 (J.C. McDonnell, December 2011). City of Edmonds Operational Policy The City of Edmonds Building Department has adopted an operational policy to adopt a base flood elevation of Lake Ballinger. The City has adopted a base flood elevation (BFE) of 286.14 feet NAVD 88 for the lake (Figure 1). This elevation is based on the highest observed water level in the lake, which occurred during a storm in January 1997. Other Past Flood Studies Hydrologic studies for Lake Ballinger have been conducted as part of past basin and flood studies for the City of Edmonds and the City of Lake Forest Park (Aqua Terra, June 1999; Clear Creek Solutions, June 2008; Clear Creek Solutions, January 2009; Otak, December 2009). None of the studies have resulted in a base flood elevation for the lake that has been approved by FEMA. Based on HSP-F hydrologic modeling, the RESUB FEB 2 3 2012 STREET�UCTY OF EDMODILDING SNT FILE Mr. Frank Trieu Page 2 February 13, 2012 elevations of the lake have been predicted to be 284.14 feet NAVD 88 1 for the 10-year, 284.90 feet NAVD 88 for the 50-year, and 285.19 feet NAVD 88 for the 100-year flood elevation (Clear Creek Solutions, June 2008). I could not find any reference to the estimated return period of the January 1997 storm that resulted in an observed peak flood elevation that is higher than the 100-year flood elevation predicted by Clear Creek Solutions. Recommendations The applicant must follow local building code requirements in construction of the new structure. I recommend the following flood control related measures, provided they are not in conflict with any of the City's building requirements: The finished floor elevation of the proposed structure on the project site must be a minimum of 1 foot above the City's adopted BFE of 286.14 feet NAVD 88. Given the lack of an approved FEMA flood study, I recommend constructing the finished floor for the new structure 2 or 3 feet above the City's adopted BFE. Selecting a higher finished floor elevation would help protect against uncertainty in the adopted BFE. In addition, a conservative selection of the finished floor elevation would help protect the structure against the potential effects of wind generated waves. For instance, the wind fetch across the lake is a distance of approximately 2,800 feet. Assuming a 60 mph wind velocity across the lake, a wave height of 1.9 feet could develop as a result of the wind (Washington State Department of Ecology, 1993). ■ If any portion of the structure is to be located below the BFE, the structure must be designed and constructed to resist flotation, collapse, and lateral movement when subjected to base flooding conditions. All materials installed below the base flood elevation must be flood resistant materials, such as concrete and corrosion resistant metals Vents are required in any enclosed space below the BFE not designed to resist hydrostatic forces to relieve hydrostatic pressure on the structure. A minimum of one (1) square inch of vent area is required for each square foot of enclosed space. Vents must be installed on a minimum of two sides of the structure, with the bottom of the vent within one (1) foot of the exterior adjacent grade and the top of the vent no higher than the BFE. Vents may be equipped with screens or louvers which allow for the automatic entry and exit of floodwaters. 1 The original report cites these elevations using a vertical datum of NGVD29. The following conversion was used: NAVD 88 = NGVD 29 + 3.60 Mr. Frank Trieu Page 3 February 13, 2012 ■ All machinery, and equipment should be elevated above the BFE or be designed, constructed and installed to prevent floodwaters from entering or accumulating within its components. ■ The Flood Elevation Certificate provided in Attachment B must be updated with changes in the site plan. If required by any agency or lending institution, a final version of the Elevation Certificate must be prepared once the building is constructed and data entered onto the form have been field -verified. M c C� WASy ar 576 _ S ` iISTY C �ICNAL Edward J. McCarthy, Ph.D., P.E. Mr. Frank Trieu Page 4 February 13, 2012 References City of Edmonds, June 2011. Building Department Operation Policy 062011 — Flood Plain Elevation of Lake Ballinger. Clear Creek Solutions Inc., 2008. Lake Ballinger Lake Level and Outlet Study. Prepared for the City of Edmonds. Hammond, Collier & Wade Livingstone Associates and Aqua Terra Consultants, 1999. McAleer and Lyon Creeks Drainage Basin Study. Prepared for the City of Lake Forest Park. J.C. McDonnell, December 14, 2011. Trieu Site Plan and Base Map. Mill Creek, Wash. Otak, 2009. Flood Reduction Planning Study Lyon Creek/McAleer Creek Drainage Basins. Prepared for the City of Lake Forest Park. Washington State Department of Ecology, 1993. Dam Safety Guidelines- Part IV Dam Design and Construction. Water Resources Program — Dam Safety Office. Olympia, Wash. =An; F 0 20 40 80 'i�P CF V.'ATER 1 �I� CATEGORY 3 - �¢:'::� 7/¢' G£JLR I •\ - =u � -- -- - 0.22 FZEVF ;T rF / n _ {}Jy A5 - �. tYC?.R:] r5'-• :'^A:7 G-L lxwm OY 1 ., 4133 234 10 r_ T l n% '•1 r La284.14 286-14 e�a 3. F—')+ F! —j it r t •• mas OF FLOW ELFVAIION DAY • -`-C-::•'44 E- 10-YR AND 50-YIT: CLEAR GREDC _- _ . - -. \ .1�_.1-o ., SOLUTIONS LANE LEVEL STUDY (JJNE 2008) _ 33,1 WE CITY OF EDMONDS WERATNM- POIJCY /D92011 _ [1 ' u FIGURE 1. SITE TOPOGRAPHY TRIED RESDENCE 7109 LAKE SAIJINOER WAY EOYONC% WA sw ET SW CITY OF EDMOND 530163 / sw m 3 242NO I= iil STREET 3 SNOHOMISH COU UNINCORPORATED 535534 k A ZONE X �-- I I � STREET Cw � STI sw 32 ZONE KING COUNTY APPROXIMATE SCALE IN FEET 1000 0 1000 N BUWEJ NATIONAL MOD INSURANCE PROGRAM FIRM sw RL000 INSURANCE RATE MAP SNOHOMISH COUNTY, — WASHINGTON AND INCORPORATED AREAS m PANEL 1315 OF 15T5 MEE WP WM FOR PANEL: NOT P ED7 oatur�am HJI Pt i. M°YMw.F IE9U[EOry GF ed E ��,weM1r��r an>'w w v uww.rnau,Eo us.E � me E MAP NUMBER 530SIC1315 E EFFECTIVE DATE: NOVEMBER 8,1999 Fcd.M Emergency M mt A&ncy i. Is an oft al copy of a portion of the Mom referenced flood map. a s-tmcted F-drr Onsuno. INS map dow fmt fall—, chrnge. am.ndmores vdaoh may haw horn made sulsaQuom to the date rn tad e dock. For the latest product information about National Flood Irrena . ram flood map. check the F ogEMA Flood Map Stole at twroi.mse.fema.gou Attachment B. Draft Elevation Certificate O.S. DEPARTMENT OF HOMELAND SECURITY ELEVATION CERTIFICATE OMB No. 1660-0008 Federal Emergency Management Agency I Expires March 31, 2012 National Flood Insurance Program Important: Read the instructions on pages 1-9. SECTION A - PROPERTY INFORMATION For Insurance Company User ` Al. Building Owner's Name Frank Trieu P,bllcylNu beer Y ' �' 'I A2. Building Street Address (including Apt., Unit, Suite, and/or Bldg. No.) or P.O. Route and Box No. FComypany?!NAICgNu bgrF_-`"- 7109 Lake Ballinger Way City Edmonds State WA ZIP Code 98026 A3. Property Description (Lot and Block Numbers, Tax Parcel Number, Legal Description, etc.) Tax Parcel Number 00488800800700 A4. Building Use (e.g., Residential, Non -Residential, Addition, Accessory, etc.) Residential A5. Latitude/Longitude: Lat. 47 46' 42.42" Long. 122 19' 43.77" Horizontal Datum: ❑ NAD 1927 ❑ NAD 1983 A6. Attach at least 2 photographs of the building if the Certificate is being used to obtain flood insurance. AT Building Diagram Number 1B A8. For a building with a crawlspace or enclosure(s): A9. For a building with an attached garage: a) Square footage of crawlspace or enclosure(s) sq ft a) Square footage of attached garage sq ft b) No. of permanent flood openings in the crawlspace or b) No. of permanent flood openings in the attached garage enclosure(s) within 1.0 foot above adjacent grade within 1.0 foot above adjacent grade c) Total net area of flood openings in A8.b sq in c) Total net area of flood openings in A9.b sq in d) Engineered flood openings? ❑ Yes ❑ No d) Engineered flood openings? ❑ Yes ❑ No SECTION B - FLOOD INSURANCE RATE MAP (FIRM) INFORMATION B1. NFIP Community Name & Community Number B2. County Name B3. State City of Edmonds 530163 1 Snohomish I WA B4. Map/Panel Number B5. Suffix B6. FIRM Index B7. FIRM Panel B8. Flood B9. Base Flood Elevation(s) (Zone Map 53061C Panel 1315 E Date Effective/Revised Date Zone(s) AO, use base flood depth) 11 /8/99 11 /8/99 A 286.14 B10. Indicate the source of the Base Flood Elevation (BFE) data or base flood depth entered in Item B9. ❑ FIS Profile ❑ FIRM ® Community Determined ❑ Other (Describe) B11. Indicate elevation datum used for BFE in Item 69: ❑ NGVD 1929 ® NAVD 1988 ❑ Other (Describe) B12. Is the building located in a Coastal Barrier Resources System (CBRS) area or Otherwise Protected Area (OPA)? ❑ Yes ® No Designation Date ❑ CBRS ❑ OPA SECTION C - BUILDING ELEVATION INFORMATION (SURVEY REQUIRED) Cl. Building elevations are based on: ® Construction Drawings' ❑ Building Under Construction' ❑ Finished Construction 'A new Elevation Certificate will be required when construction of the building is complete. C2. Elevations -Zones Al-A30, AE, AH, A (with BFE), VE, V1-V30, V (with BFE), AR, AR/A, AR/AE, AR/A1-A30, AR/AH, AR/AO. Complete Items C2.a-h below according to the building diagram specified in Item AT Use the same datum as the BFE. Benchmark Utilized Field tie to tidal watersVertical Datum NAVD 88 Conversion/Comments N/A Check the measurement used. a) Top of bottom floor (including basement, crawlspace, or enclosure floor) 287.0 ® feet ❑ meters (Puerto Rico only) b) Top of the next higher floor 297.0 ® feet ❑ meters (Puerto Rico only) c) Bottom of the lowest horizontal structural member (V Zones only) ❑ feet ❑ meters (Puerto Rico only) d) Attached garage (top of slab) ❑ feet ❑ meters (Puerto Rico only) e) Lowest elevation of machinery or equipment servicing the building 287.2 ® feet ❑ meters (Puerto Rico only) (Describe type of equipment and location in Comments) f) Lowest adjacent (finished) grade next to building (LAG) 287.2 ® feet ❑ meters (Puerto Rico only) g) Highest adjacent (finished) grade next to building (HAG) 296. ® feet ❑ meters (Puerto Rico only) h) Lowest adjacent grade at lowest elevation of deck or stairs, including 287.0 ® feet ❑ meters (Puerto Rico only) structural support SECTION D - SURVEYOR, ENGINEER, OR ARCHITECT CERTIFICATION This certification is to be signed and sealed by a land surveyor, engineer, or architect authorized by law to certify elevation information. I certify that the information on this Certificate represents my best efforts to interpret the data availab/e.l understand that any false statement may be punishable by fine or imprisonment under 18 U.S. Code, Section 1001. Check here if comments are provided on back of form. Were latitude and longitude in Section A provided by a .licensed land surveyor? ❑ Yes ® No Certifier's Name Edward J. McCarthy License Number 28576 Title Water Resource Engineer Company Name Ed McCarthy, PE, PS Address 9957 171 Ave SE City Renton State WA ZIP Code 98059 Signature Date 2-10-12 Telephone 425-271-5734 PLACE SEA' - HERE FEMA Form 81-31, Mar 09 See reverse side for continuation. Replaces all previous editions IMPORTANT: In these spaces, copy the corresponding information from Section A. Building Street Address (including Apt., Unit, Suite, and/or Bldg. No.) or P.O. Route and Box No. 7109 Lake Ballinger Way y City EdmondsState WA ZIP Code 98026 SECTION D - SURVEYOR, ENGINEER, OR ARCHITECT CERTIFICATION (CONTINUED) Copy both sides of this Elevation Certificate for (1) community official, (2) insurance agent/company, and (3) building owner. Signature Date 2-10-12 ❑ Check here if attachments SECTION E - BUILDING ELEVATION INFORMATION (SURVEY NOT REQUIRED) FOR ZONE AO AND ZONE A (WITHOUT BFE) For Zones AO and A (without BFE), complete Items El-E5. If the Certificate is intended to support a LOMA or LOMR-F request, complete Sections A, B, and C. For Items El-E4, use natural grade, if available. Check the measurement used. In Puerto Rico only, enter meters. El. Provide elevation information for the following and check the appropriate boxes to show whether the elevation is above or below the highest adjacent grade (HAG) and the lowest adjacent grade (LAG). a) Top of bottom floor (including basement, crawlspace, or enclosure) is ❑ feet ❑ meters ❑ above or ❑ below the HAG. b) Top of bottom floor (including basement, crawlspace, or enclosure) is ❑ feet ❑ meters ❑ above or ❑ below the LAG. E2. For Building Diagrams 6-9 with permanent flood openings provided in Section A Items 8 and/or 9 (see pages 8-9 of Instructions), the next higher floor (elevation C2.b in the diagrams) of the building is ❑ feet ❑ meters ❑ above or ❑ below the HAG. E3. Attached garage (top of slab) is ❑ feet ❑ meters ❑ above or ❑ below the HAG. E4. Top of platform of machinery and/or equipment servicing the building is ❑ feet ❑ meters ❑ above or ❑ below the HAG. E5. Zone AO only: If no flood depth number is available, is the top of the bottom floor elevated in accordance with the community's floodplain management ordinance? ❑ Yes ❑ No ❑ Unknown. The local official must certify this information in Section G. SECTION F - PROPERTY OWNER (OR OWNER'S REPRESENTATIVE) CERTIFICATION The property owner or owner's authorized representative who completes Sections A, B, and E for Zone A (without a FEMA-issued or community -issued BFE) or Zone AO must sign here. The statements in Sections A, B, and E are correct to the best of my knowledge. Property Owner's or Owner's Authorized Representative's Name Address City State ZIP Code Signature Date Telephone Comments ❑ Check here if attachments SECTION G - COMMUNITY INFORMATION (OPTIONAL) The local official who is authorized by law or ordinance to administer the community's floodplain management ordinance can complete Sections A, B, C (or E), and G of this Elevation Certificate. Complete the applicable item(s) and sign below. Check the measurement used in Items G8 and G9. G1. ❑ The information in Section C was taken from other documentation that has been signed and sealed by a licensed surveyor, engineer, or architect who is authorized by law to certify elevation information. (Indicate the source and date of the elevation data in the Comments area below.) G2. ❑ A community official completed Section E for a building located in Zone A (without a FEMA-issued or community -issued BFE) or Zone AO. G3. ❑ The following information (Items G4-G9) is provided for community floodplain management purposes. G4. Permit Number G5. Date Permit Issued G6. Date Certificate Of Compliance/Occupancy Issued G7. This permit has been issued for: ❑ New Construction ❑ Substantial Improvement G8. Elevation of as -built lowest floor (including basement) of the building: ❑ feet ❑ meters (PR) Datum G9. BFE or (in Zone AO) depth of flooding at the building site: ❑ feet ❑ meters (PR) Datum G10. Community's design flood elevation ❑ feet ❑ meters (PR) Datum Local Official's Name Title Community Name Telephone Signature Date Comments Check here if attachments FEMA Form 81-31, Mar 09 Replaces all previous editions Building Photographs See Instructions for Item A6. Building Street Address (including Apt., Unit, Suite, and/or Bldg. No.) or P.O. Route and Box No. State ZIP Code If using the Elevation Certificate to obtain NFIP flood insurance, affix at least two building photographs below according to the instructions for Item A6. Identify all photographs with: date taken; "Front View" and 'Rear View"; and, if required, "Right Side View" and "Left Side View." If submitting more photographs than will fit on this page, use the Continuation Page, following. Building Photographs Continuation Page Building Street Address (including Apt., Unit, Suite, and/or Bldg. No.) or P.O. Route and Box No. City State ZIP Code If submitting more photographs than will fit on the preceding page, affix the additional photographs below. Identify all photographs with: date taken; "Front View" and "Rear View'; and, if required, "Right Side View" and "Left Side View." OF EDP . Certificate of Occm)ancy Building Division This certificate is issued in accordance with.the requirements of Section 111 of the 09 International Building Code certifying. that at the time of issuance this structure was in compliance with the applicable provisions of the codes and ordinances of the city regulating construction and use of buildings. Description: 64 - Single Family Residence New Occupant: Site Address: 7109 LAKE BALLINGER WAY, EDMONDS Construction Type: VB Owner: FRANK TRIEU 7109 LAKE BALLINGER WAY EDMONDS,WA 98026-8545 '(,building Official a Permit No: BLD20110669 Parcel No: 00488800800700 Occupant Load: Occupancy Group: R-3 POST IN A CONSPICUOUS PLACE 09/27/2013 Date Issued STREET FILE, 16412 NE 10th Place DRAWING BY: Gregory W. Ashley Bellevue, Washington 98008-3707 I Proprietary information. This drawing contains confidential and/ or prirgeged information Ash ley Shoreline Design e� permitting Phone: (425) 957-9381 which b intended for thb m y specific licensed uAUDeonly. s Cop writs,disclosure,14. or dbamhtntion of thb eommunknthm b prohibhcd. AG Derfgna Copywrite NI14 • flsh(ey 'n ^ / ^ e-mail: greg@shoreline-permitting.com sliorel me Orsig„ QQtmdttmg •*** uuw.slwrr1me-permatoV.wm Setbacks tceuuired Front Sides W 1 L t d/ t Rear Other 11eiQht (t vw- 0Ftw'm Actual c(ock (0 30 Z P/L I Set Back ' Set Back ' 10 4'i i< t I� P/L Set Backl 30' j Set Back Existing -i3' 0 pier to be repaired & grated Existing 41 , pier _ I I Lake Ballinger P O PL,ANN�G OHWM Existing 10' deteriorating i sheet pile bulkhead Per ECDC 16 20 O40 C. the existing dock is nonconforming for area (7 70sf rather than 400 sf), length (a 1' rather than and width (more than 25% of lot width at about »0%). However. repairs to nonconforming docks are allowed per ECDC 23.10.220.0 as long as the repairs are valued at less than Francis Trieu 5°0 of the cost of the total replacement of the structure. Complete replacement of the existing wood dock was valued as 322.260, the proposed repairs at 7109 Lake Ballinger Way S9.260. The repair cost is less than 75,% of replacement Edmonds, WA 98026-8545 ECDC 16.20.040.C, the existing dock is nonconforming for area.(-770 sf rather tha 4011 sf), length (41' rather than 351 and width more than 25% of lot width at as-0%However, re�_te� cn onforming docks are � allowed per ECDC 23.10.220-DD a?`'�nne as -long as the repairs are valued at less than d 75% of the cost of tt LreOlacement-of he structure. Complete replacement I of the existingwood dock was valued at $22, the proposed repairs at $7,260,The 'repair cost is less than 75% of replaceme77--�� Existing floating pierg( Vicinity Map (No Scale) ftm'Vr Lat. Gal, t:— a Lake Ballinger w Golf a Site AS NOTED, !EERING ®a4e:. _ 10 g -)( ftVk five yheid &W NOZ& n r1i VU 41 vw //uIZcrAnna D. RddduQn g � �� 7101 Lake BallingeP Z!J t!s Edmonds, WA 98026-854 ' ill u, --- 60SC RECEIVED -�nK,M 5CA,. - 1"=20' SEP 18 2014 O 5 IQ 15 20 DEVELOPMENT SERVICES COUNTER SHORELINE PROJECT FOR: Francis Trieu LOCATIOLake Ballinger DATUM: NGVD 29 ROJECT DESCRIPTION: Repair existing pier. Repair piles as needed by sleeving with 7109 Lake Ballinger Way g y LAT: 47a 35' 29" North LONG: -122 59 38" West HDPE pipe and filling with coop. Repair carp &stringers as PAGE: 1 of 1 Edmonds, WA 98026-8545 LENGTH FROM OHWM: 41' SQ. FT.: 770 DATE: 4/25/2014 needed. Replace solid wood -plank decking with Thru-Flow. 1 CITY OF EDMONDS 12151h Avenue North, Edmonds WA 98020 Phone: 425.771.0220 • Fax: 425.771.0221 • Web: www.edmondswa.gov DEVELOPMENT SERVICES DEPARTMENT • PLANNING DIVISION f.nt l gym October 9, 2014 Gregory Ashley Ashley Shoreline Design & Permitting 16412 NE 10th Place Bellevue, WA 98008 STREET FILE Subject: REPAIR OF PRIVATE DOCK — LETTER OF EXEMPTION FROM THE REQUIREMENTS OF A SHORELINE SUBSTANTIAL DEVELOPMENT PERMIT Dear Mr. Ashley: The City of Edmonds Planning. Division has reviewed your September 18, 2014 request for an exemption from the requirement to obtain a Shoreline Substantial Development Permit for the purposes of repairing the private dock owned by Francis Trieu at 7109 Lake Ballinger Way. In your cover letter submitted with the associated building permit (BLD20140933), you indicated that the following work will be performed: The pier is an accessory structure to a single-family private residence. We propose to repair the piles as needed by sleeving with HDPE pipe and filling with concrete. The piles will remain in place. The caps and stringers will be repaired as needed. We will replace the solid wood -plank decking with Thru-Flow grated decking. With this understanding and after review of the plans submitted with the building permit, I have concluded that the proposed repairs to the Trieu dock are exempt from the need to obtain a Shoreline substantial Development Permit because the work proposed is normal maintenance or repair of an existing structure according to WAC 173-27-040(2)(b): Normal maintenance or repair of existing structures or developments, including damage by accident, fire or elements. "Normal maintenance" includes those usual acts to prevent a decline, lapse, or cessation from a lawfully established condition. "Normal repair" means to restore a development to,a state comparable to its original condition, including but not limited to its size, shape, configuration, location and external appearance, within a reasonable period after decay or partial destruction, except where repair causes substantial adverse effects to shoreline resource or environment. Replacement of a structure or development may be authorized as repair where such replacement is the common method of repair for the type of structure or development and the replacement structure or development is comparable to the original structure or development including but not limited to its size, shape, configuration, location and external appearance and the replacement does not cause substantial adverse effects to shoreline resources or environment. This letter provides an exemption from the need to obtain a Shoreline Substantial Development Permit from the City of Edmonds; you may wish to contact other State and Federal Agencies to determine if any further approvals are required. If you have any further questions regarding this matter, please do not hesitate to contact me at 425-771-0220. Sincerely, Mike Clugston, AICP Associate Planner Cc: File Nos. PLN20140057 & BLD20140933 Shoreline Permit Exemption File David Pater . WA State Department of Ecology Environmental Review Section Shorelines Program 3190 160th Avenue SE Bellevue, WA 98008-5452 s 5 PORT CO ufiT -1 1 0 9 LAKE BkLLinIGE2 'l EDMOn1D6 LAKE BALLIP&EP- .. H1h1ER ENE NTa VA PIP,ti85.3 Mrr � �• - Osl �- ,u M O y `" `-1 Cl C04CRETE sPW cnUe1 ci CA -44 Z (A ,. m � • cv w J ' w SCWeR GALLM 0T L 0 T 7 s 75 PYiCTFn17 inalrQCYC PAVF.AdFUT kzlb 11 SuL.y 26, 4( By IW.T IsrooT woxr SCALE 1uz20' IFaw r-jArENT Coucu PAVEMEuT to W w LOT Silt: 75/A/-65 r FILE 890 10C' CITY OF EDMONDS 250 - 5TH AVE. N. - EDMONDS, WA 98020 - (206) 771-0220 - FAX (206) 771-0221 COMMUNITY SERVICES DEPARTMENT Public Works • Planning . Parks and Recreation . Engineering LAURA M. HALL MAYOR November 27, 1995 Mailed 12/1/95 Mr. and Mrs. Rutledge 7109 Lake Ballinger Way Edmonds, WA 98026 Subject: Chain fence in public right-of-way Mr. and Mrs. Rutledge: As you know, your chain fence is within public right-of-way. You must apply for a street use permit for any portion of the fence that invades the public right-of-way. This permit is reviewed by City staff and costs $50.00 for the first three years of issuance. It is a renewable permit. The public right-of-way lies south of a line approximately thirty feet north of the curb. You were requested to apply for this permit by phone two weeks ago and the City staff has not yet received the proper application materials. Your neighbor is also being notified to apply for a street use permit for his fence and to reduce the height per the covenant recorded on your property. A copy of this letter is being sent to the Public Works Superintendent, Noel Miller. The Public Works Division is legally authorized to remove obstructions and require the land owner to pay the appropriate costs. Your cooperation in bringing this fence into compliance as soon as possible is appreciated. If there are any questions do not hesitate to contact me at 771- 0220. Si rely, ein on C. Hyde eering Coordinator GCH/sf c: Noel Miller, Public Works Superintendent a- e Ilt Wa r RUTLEDGE.DOC • Incorporated August 11, 1890 • Sister Cities International — Hekinan, Japan t � 101 rIi[e1 ' "`'° DETERMINATION OF NONSIGNIFICANCE T FIL.� Description of proposal Sports Court for single family residece Proponent Hoa Trieu Location of proposal, including street address, if any 7109 Lake Ballinger Way, Edmonds, WA 98026 Lead Agency Edmonds Planning Division The lead agency for this proposal has determined that it does not have a probable significant adverse impact on the environment. An environmental impact statement (EIS) is not required under RCW 43.21C.030(2)(c). This decision was made after review of a completed environmental checklist and other information on file with the lead agency. This information is available to the public on request. X There is no comment period for this DNS. _ This DNS is issued under 197-11-340(2); the lead agency will not act on this proposal for 15 days from the date below. Comments must be submitted by Responsible Official John Bissell Position/Title Code Enforcement Tech. Phone 771-3202 Address 250 5th Ave. N., Edmonds WA 98020 Date April 22, 1991 Signature-- X You may appeal this determination of nonsignificance to Hearing Examiner at 250 5th Ave. North, Edmonds, WA 98020 no later than 5:00 p.m. May 2, 1991 by filing a written appeal citing reasons. You should be prepared to make specific factual objections. Contact John Bissell to read or ask about the procedures for SEPA appeals. There is no agency appeal. 7 I 0 9 LAKE. BALLiN&EIZ EDMO(ADS LAKE BALLIP&•tR $ � IMF — �.�``—�--_.2 Alf pms 85.3 • � � r---.—may � , .Q. ti. .. H �15 Tooc.DLL lu M � ._ 2 lu o CONCRETE SPoPr (DOET 'g vu n . 45 x7$ A3.5�� , •� ,� cs H C11 1 f a c o ' L 0 T fo w - w ScwEK 6ALCME0T g' ' 75 r --Aa EXIST ENT c,onl GQETE PAI/EME-PT A-^)-D 6-XiS1ENT HOUSE SuLy 24, 40 By s 14.T. sPoaT wuar SCALE i'Z20' �F94fA E)USTENr COMMIrE PAVEMENT To W Lmf. `T 751 X L65' LOT a KRMFI, COUNTH APR Complete this checklist for nonproject proposals. even though questions may be answered JITNT COUNTER not apply". IN ADDITION, complete the SUPPLEMENTAL SHEET FOR NONPROJECT ACTIONS (part 0 For nonproject actions, the references in the checklist to the words "project," "applicant," and "property or site" should be read as "proposal," "proposer." and "affected geographic area." respectively. A. BACKGROUND 1. Name of proposed project, if applicable: 2. Name of applicant: �+O & T g 1 e Lt 3. Address and phone number of applicant and contact person: 030 JAEV : 7163 _lit !btkii4ofi4-z -7-74, - U 9 4. Date checklist prepared: 4 _ $ _ q ( 5. Agency requesting checklist: t,( 'CY 0 F GC W gb-$' hWk: 7 �*L f 9 '� 6. Proposed timing or schedule (including phasing, if applicable): 4 oy PK Ly q 0 7. Do you have any plans for future additions, expansion, or further activity related to or connected with this proposal? If yes, explain. WO 8. List any environmental information you know about that has been prepared, or will be prepared, directly related to this proposal. 9. Do you know whether applications are pending for governmental approvals of other proposals directly affecting the property covered by your proposal? If yes, explain. N� 10. List any government approvals or permits that will be needed for your proposal, if known. k S.S o C4 k 76 a zY P L MJ &i F, tr ►� S a �� t+�R .S S t,* go ng"-( %4-H NEe0IEp oN ToLy �l tago 11. Give brief, complete description of your proposal, including the proposed uses and the size of the project and site. There are several questions later in this checklist that ask you to describe certain aspects of your proposal. You'do not need to repeat those answers on this page. (Lead agencies may modify this form to include additional specific information on project- description.) 4 S "X' 7 13 r ( 3' S r1 SLR$ OF 0�.Al ai T'& ail 9- vs L S �Oe,r COW i h-T 7 "tE-� PLAOt s 5-JWW;r To ny OF o µONES ) j}r 71 L,w6-ZL WN-1I rW%03 i w A - 15 0J6- 12. Location of the proposal. Give sufficient information for a person to understand the precise location of your proposed project, including a street address, if any, and section, township. and range, if known. If a proposal would occur over a range of area, provide the range or boundaries of the site(s). Provide a legal description, site plan, vicinity map, and topographic map, if reasonably available. While you should submit any plans required by the agency, you are not required to duplicate maps or detailed plans submitted with any permit applications related to this checklist. PL"S be " l; PUVOi1�` +T TA-00n TO BE COMPLETED BY APPLICANT EVALUATION FOR AGENCY USE ONLY B. ENVIRONMENTAL ELEMENTS 1. Earth a. General description of the site (circle one): Flat, rolling, hilly, steep slopes, mountainous, other b. What is the steepest slope on the site (approximate percent slope)? 4r c. What general types of soils are found on the site (for example, clay, sand, gravel, peat, muck)? If you know the classification of agricultural soils, specify them and note any prime farmland. ,A -Top &Z' i 1. cot NAY d. Are there surface indications or history of unstable soils in the immediate vicinity? If so, describe. SoQko4NVW* LA-0S kfee*" c TkUG e. Describe the purpose, type, and approximate quantities of any filling or grading proposed. Indicate source of fill. `0 1 7 0 P .-CO 1 L . � Sail Fka or afke fS T e C l " ►. tris J f. Could erosion occur as a result of clearing, construction, or use? If so, generally describe. SPOPT 00o0-fi Wo0LA) DE70-€*2` 'G2oS`)ao1J . g. About what percent of the site will be covered with impervious surfaces after project construction (for -example, asphalt or buildings)? .DaN'T "OW y P LME CAWcc -rtVE 1r_ U cous eis ezzy EDIADOU 200LOW DETY. h. Proposed measures to reduce or control erosion, or other impacts to the earth, if any: P606 p�fOSrv) 2. Air a. What types of emissions to the air would result from the proposal (i.e., dust, automobile, odors, industrial wood smoke) during construction and when the project is completed? If any, generally describe and give approximate quantities if known. PDi�,CT iS COMPLE:+- O01� Cam+'SF ^M b. Are there any off -site sources of emissions or odor that may affect your proposal? If so, generally describe. 00 c. Proposed measures to reduce or control emissions or other impacts to air, if any: 00 Wt` 3. Water a. Surface: 1) Is there any surface water body on or in the immediate vicinity of the site (including year-round and seasonaT streams, saltwater, lakes, ponds, wetlands)? If yes, describe type and provide names. If appropriate, state what stream or river it flows into. 2) Will the project require any work over, in or adjacent to (within 200 feet) the described waters? If yes, please describe and attach available plans. 0 y ei, Sf r kr T fr ci B p (,k-wT 3) Estimate the amount of fill and dredge material that would be placed in or removed from surface water or wetlands and indicate the area of the site that would be affected. Indicate the source of fill material. µO 9LL 14 ZN J o L dE-0 4) Will the proposal require surface water withdrawals or diversions? Give general description, purpose, and approximate quantities if known. 5) Does the proposal lie within a 100-year floodplain? If so, note location on the site plan. 6) Does the proposal involve any discharges of waste materials to surface waters? If so, describe the type of waste and anticipated volume of discharge. pp WMit )Akltekz 0tit DI'sCato b. Ground: 1) Will ground water be withdrawn, or will water be discharged to ground water? Give general description, purpose, and approximate quantities if known. s -T Nr 0w �. w kY ER T-�) � a L v 0 W44 '►'W V.j t cc* W t-"_)m r iN 1 i+fin; `/ ht'`c- C.a ►iC;l�� i � i- tlri �� N KfS udS � o� k7 i dyo 2) Describe waste material that will be discharged into the ground from septic tanks or other sources. if any (for example: Domestic sewage; industrial, containing the following chemicals...; agricultural; etc.). Describe the general size of the system, the number of such systems. the number of houses to be served (if applicable), or the number of animals or humans the.system(s) are expected to serve. pay c. Water Runoff (including storm water): 1) Describe the source of runoff (including storm water) and method of collection and disposal, if any (include Quantities, if known). Where will this water flow? Will this water flow into other waters? If so, describe. -rwiw aµ uj WY a T- J a LU T,:D i S R-J N � oF� fi2� S' r o P� WA- o F P `ja 3 7 ko !4S -IN ro (j-RA a 015 ) J 6- 11*0 ,�t,A-i SU-e Or S' TC 2) Could waste materials enter ground or surface waters? If so. generally describe. 00 W A Y E K* Tom; �-t, S �`S Y A-0 Z.7 it d. Proposed measures to reduce or control surface, ground, and runoff water impacts, if any: poW C- 0 4. Plants a. Check or circle types of vegetation found on the site: X deciduous tree: alder, maple, aspen, other devergreen tree: fir, cedar, pine, other shrubs grass _ pasture crop or grain ,� wet soil plants: cattail, buttercup, bullrush, skunk cabbage, other ��CV Ly AO 5 -Gf _1 water plants: water lily, eelgrass, milfoil, other ^ro -rmi LWX _ other types of vegetation JJJ b. What kind and amount of vegetation will be removed or altered? $ (S 0 r it N 0vJ tN -wr ► I aj:e %e!J 1-N 7 TOF Okay V�1; T A-VbA 9 FFK-(O � 5 Q,PA -rA i c..List threatened or endangered species known to be on or near the site. 10 M o T VC RJ Q a _ d. Proposed landscaping, use of native plants, or other measures to preserve or enhance vegetation on the site, if any: J JS T a S E 0 ,,q o ctp-oA IE-ft.la "4 CR.T TL & LAS S. Animals a. Circle any birds and animals which have been observed on or near the site or are known to be on or near the site: birds: hawk, heron, eagle, songbirds, other: ............................. mammals: deer, bear, elk, beaver, other: .................................. fish: bass, salmon, trout, herring, shellfish, other: .................... b. List any threatened or endangered species known to be on or near the site. � 0 oar K N iAJI► c. Is the site part of a migration route? If so, explain. P O f w -E T i-6ff FLY' -A / d. Proposed measures to preserve or enhance wildlife, if any: 6. Energy and Natural Resources a. What kinds of energy (electric, natural gas, oil, wood stove, solar) will be used to meet the completed project's energy needs? Describe whether it will be used for heating, manufacturing, etc. 14 / b. Would your project affect the potential use of solar energy by adjacent properties? If so, generally describe. NID c. What kinds of energy conservation features are included in the plans of this proposal? List other proposed measures to reduce or control energy impacts, if any: (�D M4 (-?P1- . 7. Environmental Health a. Are there any environmental health hazards, including exposure to toxic chemicals, risk of fire and explosion, spill, or hazardous waste, that could occur as a result of this.proposal? If so, describe. pso 1) Describe special emergency services that -might be required. U /A- 2) Proposed measures to reduce or control environmental health hazards, if any: N /,�— b. Noise 1) What types of noise exist in the area which may affect your project (for example: traffic, equipment, operation, other)? N t iS-E W I-LL uD1 Kftcf f K f6CP `lWA`c�aq) G+ME-PA-TcA Oa.sr FeVM a'mAabj" A4 Z 5 ) What types and levels of noise would be created by or associated with the project on a short-term or a long-term basis (for example: traffic, construction, operation, other)? Indicate what hours noise would come from the site. ea 14 W Ord T11 c U tAZ504 f IU C*� 1 J PJ" f Q 1O 0 &J ( q — 4 P m ) % _A Ku - TC AM 0 a�-St t?-gb c-i tr7F W T Tlk k*M-& -S P i. -/ *t iAYG;q,�i oA SW'P W @ T 0�-9 LE B y d C ik+` LD era . Pr�T ;. K,c-c-p 11 vZ 3) Proposed measures to reduce or control noise impacts, if any: V" a CcVI' r W ok K 0N W & W" FJ a U q A- Vik (9-9 -�W S .C*Wl G% 0 U f 0Maec- JAiy - )J 444 .0 Cif 144"J 8. Land and Shoreline Use a. What is the current use of the site and adjacent properties? r p JWE t 1E S; pew i? b. Has the site been used for agriculture? If so, describe. c. Describe any structures on the site. W VC4 d. Will any structures be demolished? If so, what? 0 C3 Dxy t�kor e. What `is the current comprehensive plan designation of the site? h. Has any part of the site been classified as an "environmentally sensitive" area? If so, specify. i. Approximately how many people would reside or work in the completed project? N i�- j. Approximately how many people would the completed project displace? k. Proposed measures to avoid or reduce displacement impacts, if any: 0 A 1. Proposed measures to ensure the proposal is compatible with existing and projected land uses and plans, if any: -W co,6W fm Pair UALJ1r 1 OILO J Q-(r! "% i •-" 9. Housing a. Approximately how many units would be provided, if any? Indicate whether high, middle, or low-income housing. ti / tv b. Approximately how many units, if any, would be eliminated? Indicate whether high, middle, or low-income housing. P /t— c. Proposed measures to reduce or control housing impacts, if any: 0 IA- 0 M. Aesthetics a. What is the tallest height of any proposed structure(s), not including antennas; what is the principal exterior building material(s) proposed? 3. s 0 W y f 4 WOO D G-0i S_� D 6S b. What views in the immediate vicinity would be altered or obstructed? c aF Likl M OW 70 C 1, v D C S Cam+ CU -r i iGll�, c. Proposed measures to reduce or control aesthetic impacts, if any: PAi N T i Jt-( Of SPOVC fA 013 1- TV 14 A-W -,rT OR WJ C!Q L a R. 11. Light and Glare a. What type of light or glare will the proposal produce? What time of day would it mainly occur? fie 0 b b. Could light or glare from the finished project be a safety hazard or interfere with views? c. What existing off -site sources -of light or glare may affect your proposal? N /A- d. Proposed measures to reduce or control light and glare impacts, if any: 12. Recreation a. What designated and informal recreational opportunities are in the immediate vicinity? b. Would the proposed project displace any existing recreational uses?.If so, describe. 00 o T IffAv key tj 4-1 r=�crua c. Proposed measures to reduce or control impacts on recreation, including recreation opportunities to be provided by the project or applicant, if any: PO At Cr 13. Historic and Cultural Preservation a. Are there any places or objects listed on, or proposed for, national, state, or local preservation registers known to be on or next to the site? If so, generally describe. Na b..Generally describe any landmarks or evidence of historic, archaeological, scientific, or cultural importance known to be on or next to the site. N /A__ c_ Proposed measures to reduce or control impacts, if any: 0 a" 14. Transportation a. Identify public streets and highways serving the site. and describe proposed access to the existing street system. Show on site plans, if any. / b. Is site currently served by public transit? If not, what is the approximate distance to the nearest transit stop? N v c. How many parking spaces would the completed project have? How many would the project eliminate? MIL to Or &--I E AP Cc iW d. Will the proposal require any new roads or streets, or improvements to existing roads or streets, not including driveways? If so, generally describe (indicate whether public or private). e. Will the project use (or occur in the immediate vicinity of) water, rail, or air transportation? If so, generally describe. f. How many vehicular trips per day would be generated by the completed project? If known, indicate when peak volumes.wouid occur. a g. Proposed measures to reduce or control transportation impacts, if any: �N 15. Public Services a. Would the project result in an increased need for public services (for example: fire protection, police protection, health care, schools, other)? If so, generally describe. wo b. Proposed measures to reduce or control direct impacts on public services, if any. 16. Utilities i ut> > cur i it electricity natural gas, water, efuse servi telephon sanitary s we sep other. b. Describe the utilities that are proposed for the project, the utility providing the service, and the general construction activities on the site or in the immediate vicinity which might be needed. N /JAr— C. SIGNATURE The above answers are true and complete to the best of my knowledge. I understand that the lead agency is relying them to make its decision. Signature: ................. .......................... Date Submitted:........... . P.L4-V ............................... D. Supplemental Sheet for Nonproject Actions (Rezones, Code Changes, Annexations, etc.) -- Do not use this sheet for project actions. Because these questions are very general, it may be helpful to read them in conjunction with the list of the elements of the environment. When answering these questions, be aware of the extent the proposal, or the types of activities likely to result from the proposal, would affect the item at a greater intensity or at a faster rate than if the proposal were not implemented. Respond briefly and in general terms. 1. How would the.proposal be likely to increase discharge to water; emissions to air; production, storage, or release of toxic or hazardous substances; or production of noise? Proposed measures to avoid or reduce such increases are: j.0Of r� QU1P.t-b 2. How would the proposal be likely to affect plants, animals, fish, or marine life? 13 a Proposed measures to protect or conserve plants, animals, fish, or marine life are: 3. How would the proposal be likely to ppdeplete energy or natural resources? Proposed measures to protect or conserve energy and natural resources are: 4. How would the proposal be likely to use or affect environmentally sensitive areas or areas designated (or eligible or under study) for governmental protection; such as parks, wilderness, wild and scenic rivers, threatened or endangered species habitat, historic or cultural sites, wetlands, floodplains, or prime farmlands? P / � Proposed measures to protect such resources or to avoid or reduce impacts are: N /AL 5. How would the proposal be likely to affect land and shoreline use, including whether it would allow or encourage land or shoreline uses incompatible with existing plans? N1R Proposed measures to avoid or reduce shoreline and land use impacts are: N�R 6. How would the proposal be likely to increase demands on transportation or public services and utiliti.es? N /I -- Proposed measures to reduce or respond to such demand(s) are: 0 /k 7. Identify, if possible, whether the proposal may conflict with locaT, state, or federal laws or requirements for the protection of the environment. b a 0 a f [zv $A� ENVCHK3/PFORMS To : MQ LYLE G► M'ST'MkN E0&i#JE6R43(t Mrk9mEti7 of Gty of E➢HONDS s � (tE wAI' IER of SIDE PP-h;akCri DETFaT,*0PJ FLOW o� 7�oq Lkv-E 6kWs3&-fa wky UWOJDS wR q8o U WIA : HOP. i E-w � PtAPEBty OwaEft , DEK Sik al;c w-f Ly 1 Z Nd; HPUED T#+ PeAM; T F-0 t ►may Iku yu D sfaQt col)tT 00 r~y PQaPr¢Ty ArMp TA Ooi-$ o.3R coav;arkT;eAi om kf6L .Ig I I T IA) o0LP Uge To kSit yooa DEPkf'r&tFw7 hbo Vt T6 sysrtm '44VE- CT T►FE b;DE DWN"i DETEWTiflu F"IAJ n 06) µy bk" yA4-D Ddc T� THcdr "f0TTi00s SJUI " " g" JAR) 13 $L�(M r oN ttH 06i of T4f LIFE _. LT is SO rLkT AQb 7*i 6rft0ob is SOLF . 7*tK COAD6NS Co*TE Ao rmpoSS:®LE 5;-0ATio0 Foe A rerA.;")Is* tip iFs dECWO T41;; w1.7EQ 0:LL wmt uP7v I"'R.-D T wgc,N r#iif P, P&i . i#*AmK yoo Keay wwc4 we yooa coIJs:4F�L*7i0u . caE ar you et . elf . ��X��Io-A CITY OF EDMONDS CIVIC CENTER - EDMONDS, WA 98020 - (206) 775-2525 8 9 0 December 22, 1995 CERTIFIED Mr. & Mrs. Rutledge 7109 Lake Ballinger Way Edmonds, WA 98026 RE: Chain Fence/Barrier in Public Right -of -Way Dear Mr. & Mrs. Rutledge: LAURA M. HALL MAYOR gr e- !-- A N1!7z.� y DEC 2 7 1995 'I`�!'lL NEE-hagc I have reWived a copy of a November 27, 1995 letter sent to you by Gordon Hyde. The letter notifies you that you need to have an approved Street Use Permit for the chain fence located in City right-of-way. As of this date, you have not applied for a Street Use Permit. The letter is notice to you that City crews will be removing the chain fence during the first week of January 1996. If you would like to have the chain fence remain, you will need to contact Gordon Hyde at 771-0220 or myself at 771-0234 before December 29, 1995 and discuss this matter further. Sincerely, Noel F. Miller, P.E. Superintendent of Public Works OLT1017 cc: Gordon Hyde Paul Mar Mayor Hall Bill Stroud wordatMadminVutledge • Incorporated August 11, 1890 • Sister Cities International — Hekinan, Japan 1. STREET ADDRESS FILE CITY OF EDMONDS COPY AURA M. HALL CIVIC CENTER - EDMONDS, WA 98020 - (206) 775-2525 MAYOR 8 go . 1 9 C5 - December 22, 1995 CERTIFIED Mr. & Mrs. Rutledge 7109 Lake Ballinger Way Edmonds, WA 98026 RE: Chain Fence/Barrier in Public Right -of -Way Dear Mr. & Mrs. Rutledge: I have received a copy of a November 27, 1995 letter sent to you by Gordon Hyde. The letter notifies you that you need to have an approved Street Use Permit for the chain fence located in City right-of-way. As of this date, you have not applied for a Street Use Permit. The letter is notice to you that City crews will be removing the chain fence during the first week of January 1996. If you would like to have the chain fence remain, you will need to contact Gordon Hyde at 771-0220 or myself at 771-0234 before December 29, 1995 and discuss this matter further. Sincerely, Noel F. Miller, P.E. Superintendent of Public Works NM/Ik cc Gordon Hyde Paul Mar Mayor Hall Bill Stroud wordaWadminVudedge - Ic or1)()rc;Wo .fit �u;l ? •'. a) e Postal Customer: The sender of the article decribed below has made an inquiry regarding delivery of the item. The article was not located at the mailing office. Therefore, we are contacting you to determine if the article has been delivered. Please indicate below if the article has been received. Return the form in the enclosed PREADDRESSED ENVELOPE WHICH REQUIRES NO POSTAGE. Your response will assist the Postal Service in providing improved service. PLEASE RETURN BOTH PARTS I AND II -A. THANK YOU The Article Was: Date of Reply Signature of Addressee or Agent ❑ Received (Date if known) of Received ❑ Refused Remarks PS Form 1510, April 1992 Note: Use ballpoint pen and press down firmly; you are making five copies. 1. Complaint Date 2.Office Accepting �-3i-i I I CQ 4. Article Was Mailed By a. Name J a b. Return Addre96 As On Article Mailed q/ /0 - a2 -1-/- c. Ci ty,Cialmd�/� 0dState f. Day Telephone Number (Include Area Code) 6. Article Was Mailed a. Date b. Time Part II -A U.S. Postal Service Mail Loss/Rifling Ro (City and State) S L(� T . ZIP+4 Asa 7. Article Was Sent ❑ 1 st-Class Month Day Year ❑AM -L ! .5 (Hour) �'PM ❑ Other 9. Special Services 3. Complaint Doss ❑ 5. Article Was Addressed To a. Name /;JI - 11n,-5 IC14 /e dy e b. Address As On Article Mailed 7/DPI C. City, d. State e. ZII f. Day Telephone Number (Include Area Code) S. Type of Mail ❑Parcel Post Metter ❑ Parcel � e- d I ❑ Other (Specify) 54 ❑ Special Handling ❑ Special Delivery ❑ Certifi ❑ Return Receipt for Merchandise No. / 4 %S �2*0-?CDS No. 10. Place of Mailing Name and/or Address of Location Checked ❑ Main Post Office /,! �- ❑ Station or Branch �/ V oe ��}5 %�- 0-6 /e-e- ❑ Contract Station ------------------------------------------------- Collection Box City and State of Location C ed I-------------- -- i ZIP+4 for Location Checked ❑Residence or Business n -7 Gt) 00 11. Contents of Article (Describe in detail, size, color, brand name, serial no., and amount, etc.) 12. Value !! ri � /� X `� PrJ Je /die rig / h �� f' $ PS Form 1510, April 1992 N The City of Edmonds f" EASEMENT No .......................... NEW CIONSTRV�PTION"JA ��O- "EPAIl,,- OWNER.... .. . ..... P . ........... ----- CONTRACTOR .................................................................................................. PERMIT No . ............... d ADDRESS ...... LaKa ........ lBcLAl-Lr',.cjQ-r ...... Way ............ LEGAL DESCRIPTION: LOT No . ..................................... ........ BLOCK No . ............................................ LU "i f0c I NAME OF ADDITION ju..rN-Q- . (9.,7.a q- � -.-Ta Approved: DATE................................. ............... y ......................................................................