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2003 studyCritical Areas Study Talbot Park Estates Edmonds, Washington Prepared for: The City of Edmonds Development Services Department 121 Fifth Avenue North Edmonds, WA 98020 Prepared by: Anthony Roth May 5, 2003 AC BOTH ENVIRONMENTAL SERVICES 115 NORTH 49'" SiREET • SEATTLE, WASHMGTM 98103 206.784.4755 Table of Contents Table of Contents Preface.................................................................................................. ii 1. Introduction......................................................................................1 2. Water Resources Evaluation. ................................. . ...... . ................... 3 2.1 Introduction.............................................................................3 2.2 Wetlands................................................................................_ 3 2.2.1 Methodology..................................................................3 2.2.2 Investigation Results......................................................6 2.3 Stream.................................:.................................................11 3. Bibliography..................................................................................12 List of Figures 1. Vicinity Map.....................................................................................2 2. Site Map............................................................................................4 3. Emergent Wetland at west boundary, looking into the property fromthe west........................................................................... 8 4. Another view looking east into the property ....................................9 5. Looking northwest on the adjacent property ....................................9 List of Tables 1. USFWS Plant Indicator Status..........................................................6 2. Wetland Functions and Values......................................................... 7 Critical Areas Study Talbot Paris Estates Preface Preface At the request of the City of Edmonds (City), this report has been prepared as a third -party wetlands and creek evaluation of the subject property, the proposed plat of Talbot Park Estates. In preparing this report, AC Roth Environmental Consultants (RES) has used site information and survey mapping of RES wetland flag locations provided by Lovell-Sauerland and Associates, as referenced herein. Findings reported herein are based on information gathered in the field at the time of investigation by RES, RES's understanding of 1997 Washington State Wetlands Identification and Delineation Manual (Ecology 1997), and RES's understanding of federal, state and local regulations governing wetland and stream areas_ Prior to preliminary and final design or any construction, all appropriate regulatory agencies should be contacted to verify the findings of this report, and to obtain appropriate approvals and permits_ The wetland boundary, wetland, and stream classification and recommended buffers are RES's best professional opinion based on the circumstances and site conditions at the time of its study. The final wetland boundary determination, classification of wetlands and streams, and the required buffers and setbacks are subject to change by the appropriate federal, state, and local jurisdiction. Critical Areas Study Talbot Park Estates Introduction 1. -Introduction The subject property is an approximate 2 acre site located at 7701 170 Street SW, Edmonds, Washington, near the intersection of 171" Street and Sea Lawn Drive. From discussion with the City, the applicant proposes to develop the site for a single family residential development. The purpose of this report is to present a third -party analysis of site water resources, consistent with the requirements of the City of Edmonds Critical Areas (Edmonds Municipal Code [EMC] §20.15B)- A series of consultants have evaluated this and a property to the west. A May 31, 2002 Wetland Evaluation was prepared by Terra Associates for a property located at 17015 Talbot Road (Attachment A)_ This property's easterly boundary forms the westerly segment of the subject property's northwestern corner. Terra Associates found a wetland which was indicated to extend easterly onto the subject property, but the offsite wetland area was unsurveyed- A June 3, 2002 Critical Area Reconnaissance Report (Attachment B) was prepared by Wetland Resources, Inc- evaluated the "potential presence of jurisdictional wetlands" on the subject property. This "forested and scrub -shrub wetland" was sketched as approximately 1800 square feet in area. It does not appear that a survey of this evaluation was performed. In February of 2003, Pentec Environmental prepared a report entitled Third -Party Review of Critical Areas Study of the Talbot Park Estates (Attachment C), on behalf of the City. In the absence of a prior formal delineation of wetlands on the subject property, Pentec Environmental conducted a "preliminary wetland delineation of the onsite portion of the wetland". Using GPS survey methods to establish approximate location of delineated wetland boundaries, the conclusion of this last report was that the onsite and offsite portions of the wetland appear to total 2,700 square feet, but that more careful delineation and complete survey of the wetland boundary would need to be conducted. Critical Areas Study Talbot Park Estates Introduction 2. Water Resources Evaluation 2.1 Introduction On April 2, 2003, RES staff performed on -site investigations to determine the presence, type and extent of water resources on the subject property. The primary objectives of the site evaluations were: 1) the identification of any streams and wetlands under the jurisdiction of the U.S. Army Corps of Engineers (Corps); and 2) the delineation of all water resources subject to land use review and regulation by EMC § 20.15B. On -site water resources include approximately 1,374 SF of scrub -shrub and emergent wetlands located in the northwest corner of the Taylor Park site and extending to the west (Figure 3). The total size of the wetland is. approximately 4,485 SF. A stream enters the site at its southeast corner and flows in a northerly direction near the east property boundary. Under Section 404 of the Clear. Water Act, the ACOE has jurisdiction over the waters of the United States, including streams, lakes, ponds and wetlands. If no fill of water resources is anticipated, direct contact with ACOE is not required and the City of Edmonds would be the lead regulatory agency for site permitting. 2.2 Wetlands 2.2.1 Methodology Prior to conducting field evaluation, a number of sources were consulted. The National Wetland Inventory (NWI) has evaluated wetlands throughout the Stanwood area, using the system described in Classification of Wetlands and Deepwater Habitats of the United States (Cowardin 1979). The NWI mapping, as portrayed at hitp://www.nwi.fws.i;ov/, fails to identify any wetlands or streams on or in the vicinity of the subject site. Soils on the site have been mapped as the Alderwood-Everett gravelly sandy loam and Alderwood-Urban land series by the USDA Soil Conservation Service (SCS). Neither of these is listed as a hydric soil on the Official Hydric Soils List for Snohomish County (SCS, 1994). To perform the wetland delineation for the site, the 1997 Washington State Wetlands Identification and Delineation Manual (Ecology 1997) was used. Critical Areas Study Talbot Park Estates Introduction an ar LMow= 072701-1-016-000 O / 15 �t„ �� < TOP a emvl reAW �. `. x r (amr�wr MW VAIM uq 10, A OF a pa 7A a a 0EOmXH ,& ol0utr71 �:. ' �'�'.. r � � —CAlE00RY N STREAM r cr be ZOLaIN ARUM ANDMFL 0AMD 6 02704-1-040-OM r , -->Ior a smut SAW I <aowwEr woN Ulm UN j �� ` :r:`:` 3—aleoonr N smawr r �t \ 'A OO O O Cm. a'oem E • JN1E Y` \`Y 4 —IV SIeAN PER �.—tP3•� 9 ,,.,r INDOOMMDODATM OF WE SaaK J ,�`\ \ ,� .:rR' • `` r ♦ 072706-1-=-OOD'7 91AMIY AN 1110m /\ 6060-000-M-0000- Figure 2. Ske Map Critical Areas Study q Talbot Park Estates Water Resources Evaluation The methodology in this manual recognizes that the three parameters of hydrology and wetland plants are generally found in wetlands and that these parameters are important in the establishment and maintenance of wetland communities. Within the methodology, indicators are evaluated in the field to determine satisfaction of each of the three parameters for establishment of wetland boundaries: HydrolAylic Plants - The US Fish and Wildlife Service (Reed, 1988 and 1993) has established a rating system which has been applied to commonly occurring plant species on the basis of their frequency of occurrence in wetlands. Species indicator status expresses the range that plants may occur in wetlands and non -wetlands (uplands)_ Within the State and federal methodology, satisfaction of the hydrophytic plant community criterion occurs when the plant community is comprised of 50 percent or more of the dominant species which are adapted to or tolerant of saturated soil conditions: an indicator status of facultative (FAQ, facultative wetland (FACW), or obligate (OBL) wetland (Table 1). Modifiers are used with the indicator categories to more specifically define the frequency of occurrence. A positive (+) sign indicates plants are more frequently found in wetlands than the category_ indicates, whereas a negative (-) sign indicates plants are less frequently found in wetlands than the indicator signifies. A status of FAC- does not meet the hydrophytic plant community criterion. 2. Hydrology - Evidence of permanent or periodic inundation, or (at least) soil saturation to within 12 inches of the surface for one week or more during the growing season (soil temperatures above 41 °F); indicators other than standing water or soil saturation include stained leaves, soil surficial cracking or water -borne litter. 3. Hydric soils - Soils that are saturated, flooded, or ponded enough during the growing season to develop anaerobic conditions in the upper soil horizons, or to the depth of 12 to 18 inches; indicators include high organic content, low soil chroma (Munsell' matrix chroma of 2 with mottles or less than 2 without mottles) or gleying. 1 Munsell Soil Color Charts, Kollmorgan Instruments Corporation, Baltimore, Maryland Critical Areas Study 5 Talbot Park Estates Water Resources Evaluation The methodology in this manual recognizes that the three parameters of hydrology and wetland plants are generally found in wetlands and that these parameters are important in the establishment and maintenance of wetland communities. Within the methodology, indicators are evaluated in the field to determine satisfaction of each of the three parameters for establishment of wetland boundaries: lydrophytic Plants - The US Fish and Wildlife Service (Reed, 1988 and 1993) has established a rating system which has been applied to commonly occurring plant species on the basis of their frequency of occurrence in wetlands. Species indicator status expresses the range that plants may occur in wetlands and non -wetlands (uplands). Within the State and federal methodology, satisfaction of the hydrophytic plant community criterion occurs when the plant community is comprised of 50 percent or more of the dominant species which are adapted to or tolerant of saturated soil conditions: an indicator status of facultative (FAQ, facultative wetland (FACW), or obligate (OBL) wetland (Table 1). Modifiers are used with the indicator categories to more specifically define the frequency of occurrence. A positive (+) sign indicates plants are more frequently found in wetlands than the category indicates, whereas a negative (-) sign indicates plants are less frequently found in wetlands than the indicator signifies. A status of FAG does not meet the hydrophytic plant community criterion. 2. Hydrology - Evidence of permanent or periodic inundation, or (at least) soil saturation to within 12 inches of the surface for one week or more during the growing season (soil temperatures above 41 °F); indicators other than standing water or soil saturation include stained leaves, soil surficial cracking or water -borne litter. 3. Hydric soils - Soils that are saturated, flooded, or ponded enough during the growing season to develop anaerobic conditions in the upper soil horizons, or to the depth of 12 to 18 inches; indicators include high organic content, low soil chroma (Munsell' matrix chroma of 2 with mottles or less than 2 without mottles) or gleying. 1 Munsell Soil Color Charts, Kollmorgan Instruments Corporation, Baltimore, Maryland Critical Areas Study 5 Talbot Park Estates Water Resources Evaluation Table 1. USFWS Plant Indicator Status Plant indicator. Status Indicator Status Category Abbreviation Definition (.Probability of Occurrence) Obligate Upland UPL Occur rarely in wetlands (less than 99 percent) and almost always in uplands (greater than 99 percent) Facultative Upland FACU Occur rarely in wetlands (less than 99 percent) and almost always in uplands (greater than 99 percent) Facultative FAC Equal likelihood in uplands and wetlands (33 to 67 percent) Facultative Wetland FACW Occur sometimes in wetlands (1 to <33 percent), but more likely in uplands (>67 to 99 percent) Obligate Wetland OBL Occur rarely in uplands (less than 99 percent) and almost always in wetlands (greater than 99 percent) Not Listed NL Not listed in USFWS National List of Plant Species that Occur in Wetlands For the analysis of this site, the presence of dominant hydrophytic vegetation was used for the principal delineator of the boundary between wetland and upland areas, supplemented on a case -by -case basis, with organic content or soil color evaluation to verify presence of hydric soils and in the absence of a positive indicator of wetland hydrology, use of professional judgement. At several locations which supported uniform or homogeneous plant cover within the delineated wetland areas, sample plots (Appendix A) were established for recording of wetland characteristics and for an assessment of wetland functions, including those described in Table 2. 2.2.2 Investigation Results RES conducted a site visit in April 2003, concurrent with surveyors from Lovell-Sauerland and Associates, to determine the presence, type and extent of critical areas (wetlands and streams) on the subject property. Sample plots were established in areas of homogeneous vegetation within the wetland areas evaluated. For each habitat type, the dominant vegetation (in addition to the common and infrequently - Critical Areas Study 6 Talbot Park Estates Water Resources Evaluation Table 2 Wetland Functions and Values Wetland Function DefitMion highest Value Lowest Value Hydrologic support provision of water for biological productivity and permanently saturated or inundated systems groundwater recharge temporarily inundated or saturated hydrologically isolated depressions Streembase flow contribution potential the wetland's potential and ability to contribute to stream location in the upper segment of the basin and low located in the lower basin and and ability base flow based on its location within the basin and its recharge rate gr either of the following; connected either high recharge rate, without surface water connection with a stream wetland or with permanent outlet to stream lid permanent outlet or not connected one of the following: permanently flooded, outflow to a stream greater than inflow or topography favoring discharge Shoreline stabilization presence of wetland plants along the stream shoreline In a Woody vegetation at least 200 yards in width submergent vegetation less than configuration which serves to dissipate periodic increased 100 yards wide flow or current Water quality Improvement, including toxicant retention is related to soil type; sediment retention organic soils = toxicant retention; areas of reduced fast -flowing streambed composed sediment and toxicant retention, and nutrient uptake/conversion are related to presence of water velocity containing vigorous plant growth = of mineral soils, with minimal plant nutrient uptake or conversion and macrophytes In the subject waters for blofiltration; pollution sediment retention and nutrient uptake/conversion; growth and no pollutant Inputs pollution reduction reduction Is related to the opportunity for pollutant Inflow to point or non -point sources of pollution = pollutant the wetland removal opportunity Storm/floodwater management based on the location and of the wetland within the basin wetland with impermeable or slowly permeable less than 5 acres and the wetland's physical features soils comprising <5 percent of the upslope watershed and either no permanent outlet or constricted outlet with unconstricted inlet or evidence of floodplain or expansive flooding within one year; wetland of more then ten acres Groundwater recharge variables include periodicity and rate of flow, wetland size year-round, open water wetlands greater In size small, topographic low areas which and depth, surface topography and underlying soils and than 10 acres with water depths greater than 10 are only seasonally inundated geology feet Wildlife habitat and biological based on habitat characteristics and biological process high community diversity, valuable species support, absence of or limited manifestation functions values, including; habitat type, diversity, size and value can provide relatively equal proportions of open of community diversity, valuable within wetlands and adjacent uplands; food quality and water and vegetative cover and have refuge species support, relatively equal diversity; biological community diversity and structure; plant potential proportions of open water and productivity and support for and presence of game; vegetative cover and refuge commercially important or unique species; and potential opportunities for refuge and provision of surrounding vegetation with potential to reduce visual and noise disturbance Critical Areas Study 7 Talbot Park Estates Water Resources Evaluation occurring species) was recorded for each vegetation layer and the soil type/soil color and depth of soil saturation recorded (See representative data sheets in Appendix A). The on -site water resource is a 0.032 acre portion (Figures 3, 4, and 5) of a larger (0.10 acre) scrub -shrub and emergent, seasonally flooded/saturated wetland, as classified by Cowardin, et al. (1979). The wetland is found in a shallow depression on the northeast corner of the subject property and extends to the west, onto an adjacent property. Figure 3. Emergent Wetland at west boundary, looking into the property from the west. Note emergent zone and standing water. The wetland on the site has no overstory and the shrub layer is principally comprised of Sitka willow (Salix sitchensis, FACW), salmonberry (Rubus spectabilis, FAC+), and red alder (Alnus rubra, FAC), with some Himalayan blackberry (Rubus discolor, FACU) cover entering the wetland area. Other than sparse creeping buttercup (Ranunculus repens, FACW) and occasional (Juncus effusus, FACW), the herb layer throughout the majority of the fringing scrub -shrub zone is absent. The vegetation in the more central emergent area, in which standing water was 1 to 2 inches deep at the time of evaluation, was dominated by Pacific water parsley Critical Areas Study Talbot Park Estates �.� �� •L .j � ,W \ tt 7,, 1' t yL t Fl Y• •� � +3 R ..�.... N,\ i •i " of , • Figure•ther view looking east into the • • 1 • Upland ;-.. r Wetland 441. ..�11 : i/•;/ w.••e•:i..,�ti7i.', • �f���'• •' �a� v"�w.� /!J 1 :t; Jj t `I Water Resources Evaluation (Oenanthe sarmentosa, OBL). The predominance of the vegetation supports the hydric vegetation criterion. Surface soils range from very dark grayish brown (IOYR 3/2) silt to silt loam with dark yellowish brown (1 OYR 4/6) mottles in the upper 12 to 18 inches at the wetland boundary, to black (IOYR 2/1) very organic loam in the interior of the wetland. Similar to the findings of Pentec, distinct change in soil color and change in topography separated wetlands from uplands, with soil colors of dark yellowish brown 10YR 3/3 and 10YR 3/4. Soil colors support satisfaction of the hydric soils criterion. Hydrologic support for the wetland are shallow subsurface flows. At the time of April 2003 sampling, the soil saturation at the wetland boundary was at a depth of 8 inches; standing water in the more central portions of the wetland was between 2 and 3 inches. Satisfaction of the hydrology criterion for these locations was based on soil saturation and presence of standing water. Therefore, all criteria are met for consideration of the delineated area as a wetland, satisfying the conditions of EDC §20.15B.130B. No wildlife associated with this resource, other than typical songbirds, was noted at the time of site investigation. Due to its small size and location in an urbanized area, the wetland area on the site serves limited functions for hydrologic, water quality, and wildlife support, including habitat. Limited hydrologic support functions include stream baseflow contribution. In terms of water quality functions, values are low for sediment/shoreline stabilization and low for retention/transformation of sediments, nutrients, or toxicants. Natural biological functions are similarly low in value, including primary productivity, detrital transport, nutrient cycling/utilization, and food chain support. Habitat functions are low for all species but amphibians and insects. Socioeconomic functions are limited to aesthetic, which are judged to be low, largely based on size and location of the wetland. Since the wetland is greater than 2,500 square feet in area, it is regulated by the City (EMC §20.15B.020.TT). The wetland is classified as a Category 3 wetland (EMC §20.15B.060), since it is equal to or less than 1 acre and greater than 2,500 square feet and that has one wetland class. Under EMC §20.15B.130C, 25 foot buffers are required. Critical Areas Study 10 Talbot Park Estates Water Resources Evaluation 2.3 Stream A stream locally referred to as Outfall Creek (Terra Associates 2002) enters the site at its southeast corner and flows in a northerly direction near the east property boundary. The approximate stream bank boundaries and the centerline are found in Figure 2 and documents submitted by LSA in May 2002. In agreement with Pentec's findings, the stream should be classified as a Category 2 stream under EMC 20.15B.060. Due to barriers, this stream is not used by salmonids and would therefore be buffered on either side by 25 foot buffers (EMC 20.15B.120). In April 2003, RES measured the width of the stream at various locations along its course, and is in agreement with Pentec's estimate that the average width is 30 inches, yielding an average width west of centerline of 15 inches. Critical Areas Study 11 Talbot Park Estates 91 3. Bibliography Cowardin, L.M., V. Carter, F.C_ Golet and E.T. LaRoe. 1979. Classification of wetlands and deepwater habitats of the United States. Office of Biological Services, Fish and Wildlife Service, U.S. Dept. of the Interior, FWS/OBS-79/31. Reed, P., Jr. 1988. National list of plant species that occur in wetlands: Northwest (Region 9). U.S. Fish Wildl. Serv. Biol. Rep. 88(26.9). Reed, P., Jr., et al. 1993. 1993 Supplement to List of Plant Species that Occur in Wetlands: Northwest (Region 9). U.S. Dept. Interior Fish Wildl_ Serv. December 1993 United States Department of Agriculture, Soil Conservation Service. 1983- Soil Survey of Snohomish County, Washington. Prepared in cooperation with the Washington Agricultural Experiment Station. Washington State Department of Ecology. 1997. Washington State Wetlands Identification and Delineation Manual. Publication No. 96-94. March 1997. Critical Areas Study 12 Talbot Park Estates