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Talbot_Critical Areas Report 2010 04 15.pdf CRITICAL AREAS REPORT AND MITIGATION PLAN Talbot Road – Perrinville Creek Drainage Improvement Prepared for City of Edmonds Public Works Department April 2010 Note: Some pages in this document have been purposefully skipped or blank pages inserted so that this document will copy correctly when duplexed. CRITICAL AREAS REPORT AND MITIGATION PLAN Talbot Road – Perrinville Creek Drainage Improvement Prepared for City of Edmonds Public Works Department 121 5th Avenue North Edmonds, Washington 98020 Prepared by Herrera Environmental Consultants, Inc. 2200 Sixth Avenue, Suite 1100 Seattle, Washington 98121 Telephone: 206/441-9080 April 15, 2010 Disclaimer Herrera Environmental Consultants, Inc. has prepared this report for use by the City of Edmonds. The results and conclusions in this report represent the professional opinion of Herrera Environmental Consultants, Inc. They are based in part upon (1) site reconnaissance, and (2) examination of public domain information concerning the study area. The work was performed according to accepted standards in the field of jurisdictional wetland determination and delineation using the Corps of Engineers Wetlands Delineation Manual (Environmental Laboratory 1987), the Interim Regional Supplement to theCorps of Engineers Wetlands Delineation Manual: Western Mountains, Valleys, and Coast Region (Environmental Laboratory 2008), and the Washington State WetlandsIdentification and Delineation Manual (Ecology 1997). However, final determination of jurisdictional wetland boundaries pertinent to Section 404 of the Clean Water Act is the responsibility of the Seattle District of the U.S. Army Corps of Engineers. Various agencies of the state of Washington and local jurisdictions may require a review of final site development plans that could potentially affect zoning, buffer requirements, water quality, and/or habitat functions of lands in question. Therefore, the findings and conclusions in this report should be reviewed by appropriate regulatory agencies before any detailed site planning and/or construction activities. Contents Introduction ......................................................................................................................................1 Applicant ...................................................................................................................................1 Project Background ..................................................................................................................1 Project Description ...................................................................................................................4 Summary .........................................................................................................................4 Phase 1 ............................................................................................................................4 Phase 2 ............................................................................................................................7 Applicable Laws and Regulations ..........................................................................................13 Study Objectives .....................................................................................................................13 Methods and Materials ...................................................................................................................15 Review of Available Information ...........................................................................................15 Wetlands .................................................................................................................................15 Wetland Delineation......................................................................................................15 Wetland Classification, Rating, and Functional Assessment ........................................16 Fish and Wildlife Habitat Conservation Area Assessment, Classification, and Habitat Management Plan ............................................................................................................18 Streams ..........................................................................................................................18 Puget Sound Nearshore .................................................................................................19 Species ..........................................................................................................................19 Frequently Flooded Areas .............................................................................................20 Results ............................................................................................................................................21 Analysis of Wetland Conditions .............................................................................................21 Previously Mapped Wetlands .......................................................................................21 Mapped Soils .................................................................................................................21 Wetland Delineation......................................................................................................24 Evaluation of Wetland Functions ...........................................................................................28 Wetland A .....................................................................................................................28 Analysis of Fish and Wildlife Habitat Conservation Area Conditions ...................................28 Streams ..........................................................................................................................28 Puget Sound Nearshore .................................................................................................30 Buffers ...........................................................................................................................31 Fish and Wildlife Species .............................................................................................32 Frequently Flooded Areas .......................................................................................................32 Mitigation Plan and Management Recommendations ...................................................................35 Mitigation Sequencing ............................................................................................................35 Avoid the Impact ...........................................................................................................35 Minimize the Impact .....................................................................................................35 Rectify the Impact .........................................................................................................36 Reduce the Impact .........................................................................................................36 Compensate for Impacts ................................................................................................36 Monitor Mitigation Areas .............................................................................................36 jr 08-04119-000 talbot critical areas report.doc i Wetland Mitigation and Stream Restoration ..........................................................................36 Riparian Buffer Enhancement ................................................................................................42 Goals and Objectives ..............................................................................................................42 Performance Standards ...........................................................................................................43 Wetland Mitigation Areas .............................................................................................43 Stream Restoration and Riparian Buffer Enhancement Areas ......................................43 Site Plan – Phase 2 ..................................................................................................................44 Monitoring, Habitat Management, and Site Maintenance Plan ..............................................45 Monitoring ....................................................................................................................46 Habitat Management and Site Maintenance .................................................................46 Frequently Flooded Areas .............................................................................................47 Limitations .....................................................................................................................................49 Regulatory Implications .................................................................................................................51 Clean Water Act Section 404 .................................................................................................51 Edmonds Community Development Code .............................................................................51 References ......................................................................................................................................53 Appendix A Construction Drawings Appendix B Wetland Delineation Methods Appendix C Wetland Delineation Data Forms Appendix D Wetland Rating Forms Appendix E Representative Site Photographs jr 08-04119-000 talbot critical areas report.doc ii Tables Table 1.Summary for Wetland A. ..............................................................................................27 Table 2.Native plant species planned for installation in proposed wetland mitigation areas for the Talbot Road – Perrinville Creek Drainage Improvement Project. ...........41 Table 3.Native plant species planned for installation in proposed riparian buffer enhancement areas for the Talbot Road – Perrinville Creek Drainage Improvement Project. ....................................................................................................42 Figures Figure 1.Project area and vicinity map for the Talbot Road – Perrinville Creek Drainage Improvement Project. ......................................................................................................2 Figure 2.National Wetland Inventory mapped wetlands and mapped streams in the vicinity of the project area for the Talbot Road – Perrinville Creek Drainage Improvement Project. ....................................................................................................22 Figure 3.Mapped soils in the vicinity of the project area for the Talbot Road – Perrinville Creek Drainage Improvement Project. ........................................................23 Figure 4.Existing conditions and critical areas and their buffers within the project area for the Talbot Road – Perrinville Creek Drainage Improvement Project. ....................25 Figure 5.Proposed clearing limits and project footprint for the Talbot Road – Perrinville Creek Drainage Improvement Project. ..........................................................................37 Figure 6.Proposed wetland and stream restoration and enhancement areas for the Talbot Road – Perrinville Creek Drainage Improvement Project mitigation plan. ..................39 jr 08-04119-000 talbot critical areas report.doc iii Critical Areas Report and Mitigation Plan—Talbot Road – Perrinville Creek Drainage Improvement Introduction This critical areas report and mitigation plan was prepared for the City of Edmonds Public Works Department (applicant), in support of the Talbot Road – Perrinville Creek Drainage Improvement Project (hereafter referred to as the project). This project is located at 8229 and 8307 Talbot Road in Edmonds, Washington (Figure 1). This report describes the proposed project; conditions of critical areas within the study area; other pertinent information in support of critical areas compliance (e.g., habitat management planning); and applicable local, state, and federal laws and regulations. It also includes a mitigation plan that describes activities that will be performed to compensate for unavoidable impacts to wetland resources and enhancement activities for riparian areas. This report will support necessary permit applications for the project. Anticipated permits include a nationwide permit from the U.S. Army Corps of Engineers (Corps), a Hydraulic Project Approval (HPA) from the Washington State Department of Fish and Wildlife (WDFW), and a land use development permit and State Environmental Policy Act (SEPA) approval from the City of Edmonds Development Services Department. Applicant Jerry Shuster City of Edmonds Public Works Department 121 5th Avenue North Edmonds, WA 98020 (425) 771-0235 Project Background The Talbot Road – Perrinville Creek Drainage Improvement Project is located near the Puget Sound shoreline near the confluence of Perrinville Creek and the local storm drain that drains Talbot road and an unnamed stream that drains from Southwest County Park (Figure 1). The project will address three issues: (1) sedimentation and aggradation of the lower portion of Perrinville Creek (the reach beginning immediately downstream of Talbot Road and extending to its mouth at Puget Sound) is causing flooding of neighboring properties; (2) inadequate fish passage through this lower reach, and (3) flooding caused by an undersized storm drain that conveys local stormwater and the unnamed stream. The project will remove sediment that has accumulated in the lower portion of Perrinville Creek, improve fish passage, replace the existing storm drain with a larger pipe, and provide channel improvements to improve fish habitat and to provide a longer-term solution to flooding problems in this reach. The project will occur on jr 08-04119-000 talbot critical areas report.doc April 15, 2010 1 Herrera Environmental Consultants Puget Sound Fish barrier High-flow bypass Unnamed Stream structure pipe outfall Perrinville Creek Unnamed Stream - piped Unnamed Stream Southwest County Park (Snohomish County Parks) Legend Figure 1. Project area and vicinity map for Area of the Talbot Road-Perrinville Creek map detail Project area Puget Drainage Improvement Project. Sound Stream or ditch Storm water Lynnwood conveyance 0125250500 Edmonds Feet Aerial Photograph: City of Edmonds (2007) Mountlake Terrace K:/Projects/08-04119-000/Projects/Vicinity_Map.mxd (12/22/2009) JAS Critical Areas Report and Mitigation Plan—Talbot Road – Perrinville Creek Drainage Improvement private property at 8307 and 8229 Talbot Road and in the Talbot Road public right of way in Edmonds, Washington. Perrinville Creek originates in the City of Lynnwood, and it flows in a northwesterly direction into the city of Edmonds and through Southwest County Park (Snohomish County Parks) before crossing Talbot Road. Perrinville Creek drains an area of 920 acres; approximately half of the watershed is in Lynnwood and half of it is in Edmonds. The upper reaches of Perrinville Creek support resident cutthroat trout and the lower reach supports anadromous fish, namely Coho salmon (WDFW 2009). Anadromous fish access is limited to the portion of Perrinville Creek downstream of Talbot Road because the current culvert configuration that conveys the stream under the road results in an approximate 2 to 3-foot drop at high flows (greater at low flows) into the pool below. The City of Edmonds plans on replacing this barrier culvert with a fish-passible culvert within the next 5 years. Between the Talbot Road culvert and Puget Sound there are two structures installed in 1994 to divert high flows directly into Puget Sound via a dedicated outfall pipe. These structures were permitted by the U.S. Army Corps of Engineers (permit number 93-4-00460) and the Washington Department of Fish and Wildlife. The bypass was designed to carry a maximum of 195 cubic feet per second (cfs). The existing stream channel of Perrinville Creek downstream of the high-flow bypass structure provides limited habitat for anadromous fish that utilize the stream – riparian conditions consist of landscaped vegetation and hardscapes (e.g., paved walkways, decks, concrete channel), and the stream channel lacks complexity and habitat features (e.g., in-channel wood). Perrinville Creek then flows through a concrete culvert (30-inch diameter) under the Burlington Northern Santa Fe Railway (BNSF) tracks that run along the Puget Sound shoreline through Edmonds, and then it discharges into Brown’s Bay. The 100-year and 10-year recurrence future-conditions peak flows of Perrinville Creek at the culvert under Talbot Road are estimated to be 225 and 112 cfs, respectively (RW Beck 1991). Future-conditions flows were estimate based on zoning maps. Peak flows downstream of the high-flow bypass structure are expected to be significantly lower than the flows at the culvert under Talbot Road. The unnamed stream flows into lower Perrinville Creek through an existing storm drain pipe approximately 150 feet upstream of Perrinville Creek’s outfall into Puget Sound. The existing storm drain pipe also conveys stormwater flows from the local neighborhood (Figure 1). Upstream of its confluence with Perrinville Creek, the unnamed stream flows through a defined ravine within Southwest County Park. This unnamed stream exits Southwest County Park and then enters an 8-inch diameter steel pipe behind the residence at 8302 Frederick Place. This pipe discharges to the local ditch and pipe system in Frederick Place. From this point, water is piped west along Frederick Place. The pipe then daylights to a 20-foot long ditch that flows into a culvert under Frederick Place. The stream daylights for a short segment on the north side of Frederick Place, and then flows through a series of pipes between Fredrick Place and 8307 Talbot Road, where it discharges through a 12-inch outfall into Perrinville Creek. The future- conditions 100-year and 25-year recurrence peak flows of the unnamed stream and local drainage are estimated to be 31 and 20 cfs, respectively, at the outfall to Perrinville Creek. The jr 08-04119-000 talbot critical areas report.doc April 15, 2010 3 Herrera Environmental Consultants Critical Areas Report and Mitigation Plan—Talbot Road – Perrinville Creek Drainage Improvement inadequate flow capacity of the existing conveyance pipe causes flooding of adjacent residences, especially the properties at 8307 and 8311 Talbot Road. The new storm drainage system is designed to convey the 25-year flow. Project Description Summary This project will occur in two phases, Phase 1 and Phase 2. Phase 1, to be completed in 2010, will address the sedimentation and aggradation issue mentioned above to alleviate the short term flooding risk during the winter of 2010-2011. Phase 2, to be completed in 2011, will address the inadequate storm drain on 8307 Talbot Road issue via installation of a larger pipe. Phase 2 will also include channel improvements to improve fish passage and fish habitat. Phase 1 Phase 1 activities are targeted at restoring the design capacity and function of the existing high- flow bypass structure to reduce the frequency of flooding, erosion, and material deposition downstream. Phase 1 activities will also include removal of a portion of the accumulated sediment from the channel immediately downstream of the existing storm drain outfall on 8307 Talbot Road (thereby restoring the outlet to free-flowing conditions and temporarily alleviating flooding problems until the City can replace the storm drain during Phase 2). Work will be performed on 8307 Talbot Road and on 8229 Talbot Road, and all work will be performed in dry conditions. Project Activities to be Performed on 8229 Talbot Road Approximately 25 to 27 cubic yards of sediment will be removed from the Perrinville Creek stream channel immediately upstream of the existing high-flow bypass structure that is located on the western property boundary of 8229 Talbot Road. Sediment will be removed with a vactor truck that will access the site via an existing easement along the west side of 8229 Talbot Road. The additional storage capacity in the stream created by these activities will allow for accommodation of deposition of future sediments that would otherwise be transported downstream of the bypass structure by storm flows during the winter of 2010-2011. Phase 1 plans in Appendix A shows the High-Flow Bypass Structure site plan. Small gabion baskets will be installed on the right bank of Perrinville Creek immediately upstream of the high-flow bypass structure to stabilize the eroding bank. To further alleviate downstream flooding, the existing weir plate immediately downstream of the high-flow bypass structure will be jr 08-04119-000 talbot critical areas report.doc Herrera Environmental Consultants 4 April 15, 2010 Critical Areas Report and Mitigation Plan—Talbot Road – Perrinville Creek Drainage Improvement temporarily replaced with a 24 inch-wide proportional weir plate to increase flow into the bypass structures during high flows, relative to the current configuration. Peak flow passing through this weir is designed to range from 10 to 14 cfs during the late fall/early winter when the area can experience large storm events. The temporary installation of this weir plate is necessary to reduce the threat of flooding to the downstream properties over the next wet season until the downstream channel can be enlarged, realigned, and restored (including removal of a fish passage barrier) during Phase 2 scheduled for 2011. A streamflow diversion pipe will be constructed upstream of the existing high-flow bypass structure to temporarily divert the stream during short periods of time when sediment is removed from the channel by a vactor truck, as well as any time when work is performed on the weir. The diversion pipe would be used in coordination with (1) an upstream block net to exclude fish from the work area, and (2) a temporary diversion dam downstream of the diversion pipe. Dewatering the channel prior to sediment removal will minimize the amount of suspended sediments that are discharged downstream. This diversion pipe would be an 18-inch pipe. The inlet would be located approximately 15-feet upstream of the high- flow bypass structure, just upstream of the sediment deposition area. An upturned elbow with a removable plug or cap will be affixed to the inlet. The outlet of the diversion pipe would tie into the high-flow bypass structure vault. Installation of the diversion pipe will involve placing a sand bag cofferdam upstream to divert the stream around the work area, excavating a trench approximately 15 feet long and 24- to 36-inches wide, coring a hole in one of the high-flow bypass structures, placing the diversion pipe, grouting the connection between the pipe and the bypass structure, and backfilling the pipe. The diversion pipe would remain plugged, except when in use for temporary streamflow diversion. Project Activities to be Performed on 8307 Talbot Road A vactor truck will be used to remove approximately 17 to 20 cubic yards of sediment from Perrinville Creek between the outfall of the existing storm drain pipe and the fence on the BNSF right-of-way (see Phase 1 drawings in Appendix A). The streambed substrate will remain gravel in the entire reach of the channel. It is also anticipated that channel excavation will expose historic streambed gravel substrate. If fine-grained soils are exposed after excavation, the channel will be over-excavated and a layer of fishmix gravel will be placed. jr 08-04119-000 talbot critical areas report.doc April 15, 2010 5 Herrera Environmental Consultants Critical Areas Report and Mitigation Plan—Talbot Road – Perrinville Creek Drainage Improvement General Measures and Best Management Practices (BMPs) During construction, the project area will be inaccessible to fish. There is potential for sediment and construction-related pollutant release to the channel due to stormwater runoff; however, temporary erosion and sedimentation control measures will be implemented to minimize sediment release downstream in Perrinville Creek. The following comprises the measures and BMPs that will be taken during this project to minimize construction-related impacts: Prior to all construction activities, a fisheries biologist will conduct a survey of the stream section within the action area to determine if fish are present. If fish are found, WDFW will be notified to determine appropriate course of action to prevent the project from impacting these individuals. Measures taken will potentially involve crowding fish upstream and installation of block nets (see below for block net placement) (WSDOT 2009). As a suspended sediment control measure, a sandbag cofferdam will be installed and submersible pumps will be used to divert flow around the area affect by construction of the diversion pipe, vactoring, and weir modifications. Cedar posts for a temporary diversion dam downstream of the diversion pipe will also be installed. This temporary diversion dam will facilitate future sediment removal (as necessary) in dry conditions, using the diversion pipe as a bypass. All construction and vactoring will occur during dry conditions. Compost filter socks will be placed at frequent intervals within the construction area, with the highest density placed just downstream of the cofferdam and the weir to intercept any sediment that may be transported downstream and onto 8235 Talbot Road. Socks will also be placed downstream of the fence on the BNSF right-of-way. Block nets will be installed directly upstream of the cofferdam location and directly downstream of the fence on the BNSF right-of-way to prevent fish from entering the work area. The upstream block net will be placed first, and fish will be crowded (as needed) downstream using the second block net as a seine. The second block net will then be secured immediately downstream of the work area. Block nets shall be in place until work is complete, flow has been returned to the channel, and the water is free of project-caused turbidity. Work will occur during the approved WDFW work window of July 1 through September 30, when fish are least likely to be present. The dewatered channel of Perrinville Creek will have flow fully restored to preexisting conditions prior to September 31. Flow will be reintroduced into the channel slowly by incremental removal of sandbags at the jr 08-04119-000 talbot critical areas report.doc Herrera Environmental Consultants 6 April 15, 2010 Critical Areas Report and Mitigation Plan—Talbot Road – Perrinville Creek Drainage Improvement cofferdam. This will prevent a large pulse of water from affecting the channel downstream, thereby minimizing any flushing of sediment. All areas disturbed by construction (only lawn and ornamental landscaping will be disturbed outside of the channel) will be restored to their prior condition, and any exposed sediments on the streambank will be seeded with a native grass seed mix. Phase 2 The proposed stormwater conveyance facility (storm drain) begins at a new catch basin to be constructed on the south side of Talbot Road approximately 60 feet southwest of the existing sewer easement at 8311 Talbot Road (see attached Phase 2 drawings in Appendix A). A new catch basin will intersect the existing storm drain pipe and convey the unnamed stream into a new storm drain pipe. The new storm drain pipe will be approximately 400 feet long and will flow north in an existing sewer easement and across a new easement on 8307 Talbot Road. The new storm drain will discharge to Perrinville Creek through a 30-inch pipe with a tide flex valve, or equivalent, approximately 60 feet downstream of the existing outfall location. The tide flex valve will prevent upstream migrating salmon from entering the storm drain. The City proposes to also improve habitat conditions in Perrinville Creek by enhancing a portion of the existing stream channel on 8307 Talbot Road and adjacent BNSF right-of-way with greater habitat complexity, improved fish access (by removing a fish barrier), and native vegetation plantings in the riparian zone to provide shade and other benefits to fish and wildlife within the stream corridor. This work will also increase the capacity of the channel to convey high flows and reduce the probability of flooding structures, compared to existing conditions. Once stream channel improvements and habitat enhancements described above are completed, the weir plate downstream of the diversion structure will be replaced with the permanent one. This 42-inch-wide permanent weir plate is designed to pass a maximum of approximately 30 cfs during large storm events, with the balance being discharged directly to Puget Sound though the existing diversion structures. The existing Perrinville Creek channel contains a partial fish barrier near the culvert inlet on the southwest side of the railroad. There is also minimal riparian vegetation characterizing the existing stream corridor in this reach, which consists mainly of invasive species (e.g., Himalayan blackberry), non-native grasses in the BNSF right-of-way, ornamental shrubs, and a significant amount of hardscaped streamside area on the property located at 8307 Talbot Road. These conditions will be ameliorated by the construction of a fish passable stream channel with grade control structures constructed of wood logs and rock boulders, which will result in a series of step pools. As mentioned, the project will also include extensive planting of riparian vegetation following construction. All in-channel work associated with the proposed project will occur in dry conditions by diverting all flow through the upstream high-flow bypass structure. A block net will be installed directly upstream of the high-flow bypass structure to prevent fish from entering the high-flow jr 08-04119-000 talbot critical areas report.doc April 15, 2010 7 Herrera Environmental Consultants Critical Areas Report and Mitigation Plan—Talbot Road – Perrinville Creek Drainage Improvement bypass structure. Other project Best Management Practices (BMPs) to prevent any suspended sediments from being transported downstream of the project action area and into Puget Sound are described later in the document. What follows is a detailed description of the various components of Phase 2: Drainage Improvements (Phase 2A) Construction of the new conveyance facility (storm drain) is currently scheduled for summer 2011 and will include primarily upland work. The outfall segment of the new facility will include some work below the ordinary high water mark and will be scheduled to occur during the approved WDFW work window while Perrinville Creek is diverted into the high-flow bypass structure for the channel modifications listed below. Work on the outfall segment will incorporate all the same general measures and best management practices for in channel work that is discussed in subsequent sections. Phase 2A consists of two parts: Phase 2A-1 and Phase 2A-2. Phase 2A-1 project components include: Installation of temporary erosion and sediment control measures (TESC) (see BMPs below) Clearing vegetation, debris, and hardscapes surrounding the new facility alignment to allow for construction. This will include removal of ornamental shrubs (including bamboo), portions of decking, walkway concrete, fences and adjacent wooden low wall from the property at 8307 Talbot Road Excavation of open trenches from the sewer easement to the outfall location Installation of the downstream segment(s) of storm drain pipe and catch basin(s) (i.e., outfall segment) during the approved WDFW work window while Perrinville Creek is dewatered Installation of streambed cobbles at the new storm drain outfall in order to dissipate energy and prevent erosion of the stream channel Site restorations including riparian plantings described below and restoration or relocation of vegetation and hardscapes at 8307 Talbot Road Installation of a plug on the outfall until flows are diverted to the new pipe, at which time a tide flex valve, or equivalent, will be permanently affixed to the outfall jr 08-04119-000 talbot critical areas report.doc Herrera Environmental Consultants 8 April 15, 2010 Critical Areas Report and Mitigation Plan—Talbot Road – Perrinville Creek Drainage Improvement Phase 2A-2 will include construction of the new storm drain from Talbot Road down the sewer easement and connection to the facility that was installed in Phase 2A-1. Phase 2A-2 will not involve any in-water work. Phase 2A-2 project components include: Installation of temporary erosion and sediment control measures Diverting flow in the existing storm drain system to the Perrinville Creek high-flow bypass using pumps or other mechanical methods Clearing pavement, vegetation, debris, and hardscapes surrounding the new facility alignment to allow for construction (this will include removal of pavement in Talbot Road and the existing sewer easement and adjacent fences) Excavation of open trenches for installation of the new storm drain pipe, catch basins, and lateral storm drains Installation of the new storm drain pipe, catch basins, and lateral Site restoration including restoration of the sewer easement and Talbot Road and any other disturbance (site restoration may also include elevating the grade of the existing sewer easement to accommodate the new conveyance facility) Plugging the abandoned portion of the existing storm drain system Connection to the Phase 2A-1 storm drain system Installation of a tide flex valve, or equivalent, to the outfall Construction of both Phase 2A-1 and Phase 2A-2 would include open trench excavation for installation of new pipes and catch basins in accordance with a temporary erosion and sediment control plan that will be developed for the project and approved by the City. BMPs such as silt fences, compost filter socks, and other temporary erosion control measures will be used to prevent construction from affecting water quality in Perrinville Creek (see BMP section below). Construction of the outfall segment of the new storm drain facility (Phase 2A-1) will be performed while the creek is dewatered. Additional discussion of dewatering and erosion control BMPs is provided below. Perrinville Creek Channel Modifications (Phase 2B) Perrinville Creek channel modifications will be scheduled to coincide with Phase 2A-1, discussed above. Feasibility analyses indicate that the elevation of the lower reach of Perrinville jr 08-04119-000 talbot critical areas report.doc April 15, 2010 9 Herrera Environmental Consultants Critical Areas Report and Mitigation Plan—Talbot Road – Perrinville Creek Drainage Improvement Creek needs to be lowered slightly so that the proposed relocated storm drain can be installed with adequate slope. The Perrinville Creek channel adjacent to the property at 8307 Talbot Road has been aggrading due to high sediment load and low gradient, which has led to flooding in the near vicinity of the stream. In the mid-1990s, the high-flow bypass structure mentioned above was installed approximately 100 feet upstream of 8307 Talbot Road property boundary to 1 alleviate flooding problems. A fish barrier was also installed in the channel immediately upstream of a culvert that conveys Perrinville Creek underneath the BNSF railroad prism. The new stream channel design has been sized to convey up to 30 cfs upstream of the new storm drain pipe outfall and 55 cfs downstream of the new storm drain pipe outfall. Stream restoration will occur along a 148-foot section of Perrinville Creek between the east side of 8307 Talbot Road and the BNSF railroad prism. The proposed stream channel cross section is a 3.5-foot bottom width with 2.5:1 or 3:1 (H:V) side slopes on the channel bank in the vicinity of the meander bend just upstream of the culvert outfall. The stream channel slope throughout the upper portion of the project area (adjacent to the residence at 8307 Talbot Road) will be decreased with the addition of several pools and weirs. This will improve fish passage. The channel design will include the use of logs and boulders to create pools and weirs and increase channel roughness that will lead to deeper flows and lower velocities, thus minimizing channel incision despite the overall drop in channel grade along the 8307 Talbot Road property. The use of logs will also provide additional habitat functions that are not present in the current stream, resulting in greater channel complexity. The existing bridge over the stream, the wooden wall along the stream, and the existing wooden deck to the northeast of the stream will be removed. The new stream channel design will also require alteration/removal of the existing concrete and tile walkway, the concrete, and portions of the surrounding landscaping. Summarized construction components of Perrinville Creek Channel Modifications include: Clearing vegetation, debris, and hardscapes surrounding the stream corridor to allow for channel construction. This will include removal of ornamental shrubs (including bamboo), portions of decking, walkway concrete, and adjacent wooden low wall from the property at 8307 Talbot Road. Channel construction will involve modifications to the existing fence in the BNSF right-of-way and removal of Himalayan blackberry and upland grasses in the BNSF right-of-way. The existing timbers near the culvert inlet on the southwest side of the BNSF railroad that function as a fish passage barrier will also be removed. Excavations and grade lowering to restore channel hydraulic capacity (channel grade will be approximately 1.0 – 1.5 feet lower than existing). 1 It appears that this fish barrier was installed as a structure to maintain channel drainage to the BNSF railroad culvert. jr 08-04119-000 talbot critical areas report.doc Herrera Environmental Consultants 10 April 15, 2010 Critical Areas Report and Mitigation Plan—Talbot Road – Perrinville Creek Drainage Improvement Streambank erodability will be reduced by installation of vegetated coir matting and increasing roughness via bank stabilization structures. Construction of wetland terraces within the proposed broader stream corridor to compensate for any impacts to the small (164 square feet in size) wetland located in the BNSF right-of-way. Installation of compost filter socks, silt fences, and other temporary erosion control measures. Installation of channel spanning logs as grade control structures to facilitate step-pool sequence with plunge pools and riffles. Grade drops will be a maximum of 6 inches, with 1.5-foot deep pools below the structures that transition back to base channel grade approximately 5 to 6 feet downstream of the structures. Installation of root wads (two or three) and rock boulders to improve habitat within the stream. The streambed substrate will remain gravel in the entire reach of the channel. It is also anticipated that channel excavation will expose historic streambed gravel substrate. If fine-grained soils are exposed after excavation, the channel will be over-excavated and a layer of fishmix gravel will be placed. Installation of streambed cobbles at the new storm drain outfall in order to dissipate energy and prevent erosion of the stream channel. Revegetation of all disturbed areas with native trees, shrubs, or herbaceous species. Installation of a permanent weir plate downstream of the existing diversion structures, after the above work is completed. General Measures and Best Management Practices (BMPs) During construction, the project area will be inaccessible to fish. There is potential for sediment and construction-related pollutant release to the channel due to stormwater runoff; however, temporary erosion and sedimentation control measures will be implemented to prevent any release to Puget Sound. The following comprises the measures and BMPs that will be taken during this project to minimize construction-related impacts: As a suspended sediment control measure, a cofferdam of sandbags will be installed at the high-flow bypass structure to divert all stream water into the bypass system and prevent any flow from reaching the proposed jr 08-04119-000 talbot critical areas report.doc April 15, 2010 11 Herrera Environmental Consultants Critical Areas Report and Mitigation Plan—Talbot Road – Perrinville Creek Drainage Improvement construction area – as mentioned, all construction will occur during dry conditions. A block net will be installed directly upstream of the high-flow bypass structure to prevent fish from entering the high-flow bypass structure. Stream flow from the existing storm drain system will be diverted to the Perrinville Creek high-flow bypass structure or to a vegetated dispersion area using a temporary pump and piping. Compost filter socks will be placed at frequent intervals within the construction area, with the highest density placed near the culvert inlet to intercept any sediment that may be transported down the newly constructed channel via stormwater to Puget Sound. An inflatable sewer pipe plug will also be installed near the inlet of the culvert as an additional measure to prevent any construction-related suspended sediment from entering Puget Sound via run-off or tidal flushing, and also to prevent any exposure of suspended sediments or construction-related turbidity to aquatic species. Prior to construction, a fisheries biologist will conduct a survey of the stream section within the action area to determine if fish are present. If fish are found, WDFW will be notified to determine appropriate course of action to prevent the project from impacting these individuals. Work will occur during the approved WDFW work window of July 1 through September 30, when fish are least likely to be present. The dewatered channel of Perrinville Creek below the high-flow bypass structure will have flow fully restored to preexisting conditions prior to September 31. Flow will be reintroduced into the restored channel slowly by incremental removal of sandbags at the high-flow bypass. This will prevent a large pulse of water from affecting the newly constructed channel, minimizing any flushing of sediment. All stormwater generated on-site during construction activities will be collected by a temporary catchment facility near the culvert inlet, pumped, and dispersed (sprayed) onto the upland grass area adjacent to the channel in the BNSF right-of-way. If this option is not feasible, stormwater will be pumped and discharged to the nearby sewer system. All areas disturbed by construction will be revegetated with native trees, shrubs, or herbaceous species. All exposed sediments will be seeded with a native grass seed mix. Rapid establishment of native grasses will stabilize soils and prevent erosion in the short-term. Establishment of native woody vegetation will serve as a long-term erosion control jr 08-04119-000 talbot critical areas report.doc Herrera Environmental Consultants 12 April 15, 2010 Critical Areas Report and Mitigation Plan—Talbot Road – Perrinville Creek Drainage Improvement measure, because riparian vegetation is known to reduce sedimentation by abating runoff and stabilizing soils through root cohesion. Applicable Laws and Regulations Activities affecting wetlands and streams are subject to a variety of federal and state regulations. Federal laws regulating activities in wetlands include Sections 404 and 401 of the Clean Water Act (United States Code, Title 33, Chapter 1344 \[33 USC 1344\]). Washington state laws and programs designed to control the loss of wetland acreage include the State Environmental Policy Act (SEPA) and Section 401 of the Clean Water Act (a federal law that is implemented in the state of Washington by the Department of Ecology (Ecology), as mandated by the Washington State Water Pollution Control Act). Chapter 23 in the Edmonds Community Development Code (ECDC) specifies wetland categories and stream types, required wetland and stream buffer widths, development standards, and mitigation requirements for critical areas in its jurisdiction. The project area lies within 200 feet of Puget Sound, and is therefore subject to the provisions of 2 the Shoreline Master Program in ECDC 23.10 and WAC 173-27-040(2)(p). Study Objectives The specific objectives of this critical areas report and mitigation plan are as follows. Conduct wetland determination and delineation activities in the study area using the routine method described in the Corps of Engineers Wetlands Delineation Manual (Environmental Laboratory 1987), the Interim Regional Supplement to the Corps of Engineers Wetlands Delineation Manual: Western Mountains, Valleys, and Coast Region (Environmental Laboratory 2008), and the Washington State Wetlands Identification and Delineation Manual (Ecology 1997). Classify all delineated wetlands using the U.S. Fish and Wildlife Service classification system (Cowardin et al. 1979). Classify all delineated wetlands using the hydrogeomorphic classification system (Brinson 1993). Classify all delineated wetlands and assess their functions using the Washington State Wetland Rating System for Western Washington– Revised (Hruby 2004), which is the classification system required by the Edmonds Community Development Code (Chapter 23.50). 2 The project will seek exemption from a Shoreline Substantial Development Permit per the requirements in ECDC 23.10 and WAC 173-27-040(2)(p). jr 08-04119-000 talbot critical areas report.doc April 15, 2010 13 Herrera Environmental Consultants Critical Areas Report and Mitigation Plan—Talbot Road – Perrinville Creek Drainage Improvement Determine the applicable wetland buffer widths required by the Edmonds Community Development Code (Chapter 23.50). Conduct stream Ordinary High Water Mark (OHWM) determination activities based on Washington Administrative Code, Section 222-16-030 (WAC 222-16-030). Describe habitat conditions within jurisdictional Fish and Wildlife Habitat Conservation Areas and their buffers. Determine the applicable stream buffer widths required by the Edmonds Community Development Code (Chapter 23.90). Prepare a Flood Hazard Assessment for City of Edmonds jurisdictional Frequently Flooded Areas. Present mitigation plan components that will provide compensation for unavoidable impacts to wetlands and their buffers. Identify applicable regulations and guidance provided by county, state, and federal authorities. jr 08-04119-000 talbot critical areas report.doc Herrera Environmental Consultants 14 April 15, 2010 Critical Areas Report and Mitigation Plan—Talbot Road – Perrinville Creek Drainage Improvement Methods and Materials This section describes the research methods and field protocols used in evaluating the conditions of wetlands and streams in the study area. Additional details about the methodology used in wetland delineations are provided in Appendix B. Review of Available Information A literature review was performed to determine the historical and current presence of critical areas in and near the study area. The sources of information include the following: Aerial photographs of the study area vicinity (Google Maps 2009) U.S. Fish and Wildlife Service National Wetland Inventory wetland data (USFWS 1999) Washington Department of Fish and Wildlife (WDFW) Priority Habitats and Species (PHS) data (WDFW 2009a) Washington Department of Natural Resources (WDNR) Washington Natural Heritage Program (WNHP) data (WDNR 2009) Natural Resources Conservation Service (NRCS) soil survey data for the study area vicinity (NRCS 2009a) Soil descriptions for the study area vicinity (SCS 1983) Hydric soils list for Washington (NRCS 2009b) Puget Sound flood elevation data (NOAA 2010) Wetlands Wetland Delineation Wetlands were delineated and regulated buffers were identified in the project area and within 200 feet of the project area. This wetland delineation was performed in accordance with the Washington State Wetlands Identification and Delineation Manual (Ecology 1997) and the Interim Regional Supplement to the Corps of Engineers Wetlands Delineation Manual: Western Mountains, Valleys, and Coast Region (Environmental Laboratory 2008), both of which are consistent with the 1987 Corps of Engineers Wetlands Delineation Manual (Environmental Laboratory 1987). These methods use a three-parameter approach for identifying and delineating jr 08-04119-000 talbot critical areas report.doc April 15, 2010 15 Herrera Environmental Consultants Critical Areas Report and Mitigation Plan—Talbot Road – Perrinville Creek Drainage Improvement wetlands, which is based on the presence of field indicators for hydrophytic vegetation, hydric soils, and hydrology. The specific methods using these three parameters are described in Appendix B. This wetland delineation was performed according to procedures specified for the routine wetland determination method (Ecology 1997). To identify potential wetlands, wetland biologists evaluated field conditions by walking through the project area. For each area that appeared to have potential wetland characteristics, data on dominant plant species, soil conditions in test plots, and evidence of hydrologic conditions were recorded on routine wetland data forms. Adjacent upland areas were also analyzed. On the basis of the collected data, a determination of wetland or upland was made for each area examined. Potential wetland areas in the study area were identified as distinct vegetation units, for which the three parameters (hydrophytic vegetation, hydric soils, and hydrology) were evaluated. A vegetation unit is an area that is determined to have relatively uniform plant communities or physical characteristics. A vegetation unit is defined by features such as species uniformity, species dominance, distinct topographic breaks, and a general uniformity of soil or hydrologic indicators. After the confirmation of all three wetland parameters, the wetland boundaries were delineated by placing orange fluorescent flagging. Test plot locations were also marked with flagging. Completed wetland delineation forms are provided in Appendix C. The locations of wetland boundaries and test plots were subsequently surveyed by Duane Hartman and Associates, Inc. Wetland Classification, Rating, and Functional Assessment Once delineated, the wetlands were classified, rated, and assessed in terms of their function. Wetland Classification The wetlands in the study area were classified according to the U.S. Fish and Wildlife Service classification system (Cowardin et al. 1979), which is based on an evaluation of attributes such as vegetation class, hydrologic regime, salinity, and substrate (Cowardin et al. 1979). The wetlands were also classified according to the hydrogeomorphic system, which is based on an evaluation of attributes such as the position of the wetland within the surrounding landscape, the source and location of water just before it enters the wetland, and the pattern of water movement in the wetland (Brinson 1993). Wetland Rating The wetlands were rated using the Washington State Wetland Rating System for Western Washington-Revised (Hruby 2004), hereafter referred to as the Ecology rating system. The Ecology rating system categorizes wetlands according to specific attributes such as rarity, sensitivity to disturbance, and functions. The system consists of four categories, with Category I wetlands exhibiting outstanding features and Category IV wetlands exhibiting minimal jr 08-04119-000 talbot critical areas report.doc Herrera Environmental Consultants 16 April 15, 2010 Critical Areas Report and Mitigation Plan—Talbot Road – Perrinville Creek Drainage Improvement attributes. The rating categories are used to identify permitted uses in the wetland and its buffer, to determine the width of buffers neededto protect the wetland from adjacent development, and to identify the mitigation ratios needed to compensate forpotentialimpacts on wetlands. The Edmonds Community Development Code (Chapter 23.50) requires the use of the Ecology rating system. Wetland Functional Assessment Wetland functions are defined as processes that occur within a wetland, such as the storage of water, cycling of nutrients, and maintenance of diverse plant communities. Wetland functions can be grouped together into three broad categories: habitat functions, hydrologic functions, and water quality functions. Wetlands are well known for their habitat functions, which benefit wildlife. Wetlands provide food, water, and shelter for fish, shellfish, birds, and mammals. They also serve as a breeding ground and nursery for numerous species. Hydrologic functions are those related to the quantity of water that enters a wetland, is stored in a wetland, or leaves a wetland. Hydrologic functions include reducing the velocity of stormwater, recharging and discharging groundwater, and providing flood storage. Water quality functions include the potential for removing sediment, nutrients, heavy metals, and toxic organic compounds. Not all wetlands perform all of the wetland functions, and the various functions are not performed equally well by each wetland. The location and size of a wetland may determine its functions. For example, the geographic location of a wetland may influence its habitat functions, and the location of a wetland within a watershed may determine its hydrologic functions or water quality functions. Many factors influence how well a wetland performs its functions: climatic conditions, the quantity and quality of water entering the wetland, and disturbances or alterations within the wetland or the surrounding ecosystem. Wetland disturbances may be the result of natural conditions, such as an extended drought, or human activities, such as land clearing, dredging, or the introduction of nonnative species. Wetland functions were assessed using the revised Washington State Wetland Rating System for Western Washington-Revised (Hruby 2004), which is approved by Ecology for evaluating wetland functions in Washington. Rating forms are provided in Appendix D. This system categorizes wetlands according to function scores related to the three parameters of water quality, hydrology (water quantity), and habitat. For the first part of the assessment, a score associated with the potential of the wetland to perform critical functions related to the three key parameters was determined for each wetland unit. This rating is based on an assessment of wetland structure and other characteristics serving as indicators of its capability to perform each given function, and a score is tallied for each category (water quality, hydrology \[water quantity\], and habitat). The second part of the rating involves a determination of the opportunity the wetland unit has to provide those various functions. This assessment characterizes the degree to which the wetland’s position in the landscape will allow it to perform a specific function (e.g., a wetland has an opportunity to improve water quality if it is located near a source of pollution). For water quality and hydrology, if there is an opportunity for these functions to be provided jr 08-04119-000 talbot critical areas report.doc April 15, 2010 17 Herrera Environmental Consultants Critical Areas Report and Mitigation Plan—Talbot Road – Perrinville Creek Drainage Improvement within the surrounding landscape of the study area, then a multiplier of 2 is applied to the potential function score, and the resulting product represents the total score. For habitat, opportunity scores are determined via a series of representative parameters, and they are then added to the potential function score to achieve the total score. The total score for these functions determines the wetland category. Using the scores on the wetland rating forms, a qualitative functional rating (high, moderate, or low) was derived for potential functions, based on supplemental guidance provided by the Ecology (2008). For water quality and hydrology functions a qualitative rating of “yes” or “no” was determined for the opportunity of each function to occur. For habitat functions a qualitative functional rating (high, moderate, or low) was assigned for the opportunity of each function to occur. A total rating score and classification category was also tallied for each wetland and is provided in the results section. Fish and Wildlife Habitat Conservation Area Assessment, Classification, and Habitat Management Plan A detailed habitat assessment of Fish and Wildlife Conservation Areas and their buffers within 200 feet of the project site was conducted per requirements discussed in ECDC 23.90.020. The following report includes a description of vegetation on and adjacent to stream areas being affected by project activities; identification of species of local importance, priority species, or species listed according to the Endangered Species Act (ESA) that may utilize Fish and Wildlife Habitat Conservation Areas or their buffers within the study area; and a discussion of any federal, state, or local special management recommendations that have been developed for species or habitats located on or adjacent to the project area. Additional technical information for stream areas provided includes a detailed assessment of stream conditions; accompanying maps (with delineated extent of City of Edmonds jurisdictional critical areas and their buffers related to project activities); a detailed description and functional assessment of the stream buffer; a habitat and native vegetation conservation strategy, proposed buffer enhancement; and a discussion of management practices to be implemented to protect stream habitat function (all included in the Mitigation Plan section). Streams Streams are considered to be one type of Fish and Wildlife Habitat Conservation Area, according to the Edmonds Community Development Code (Chapter 23.90). Within the City of Edmonds, streams are defined as “areas where surface waters produce a defined channel or bed which demonstrates clear evidence, such as the sorting of sediments, of the passage of water. The channel or bed need not contain water year-round”. The ordinary high water marks (OHWMs) of streams within the study area were delineated using the definition provided in the Washington Administrative Code, Section 222-16-030 \[WAC 222-16-030\], as no alternative definition was provided in the Edmonds Community Development Code. According to this definition, the OHWM of streams is “the mark found by examining the jr 08-04119-000 talbot critical areas report.doc Herrera Environmental Consultants 18 April 15, 2010 Critical Areas Report and Mitigation Plan—Talbot Road – Perrinville Creek Drainage Improvement bed and banks of a stream, lake, or pond water and ascertaining where the presence and action of waters are so common and long maintained in ordinary years as to mark upon the soil a vegetative character distinct from that of the abutting upland. In an area where the ordinary high water mark cannot be found, the line of mean high water in areas adjoining freshwater is the ‘ordinary high water mark.’ In an area where neither can be found, the top of the channel bank is the ‘ordinary high water mark.’ In braided channels and alluvial fans, the ordinary high water mark or line of mean high water includes the entire water or stream feature.” To delineate the OHWM, the bed and adjacent banks of streams in the study area were examined for indications of regular high-water events. Factors considered when assessing changes in vegetation include scour (removal of vegetation and exposure of gravel, sand, or other soil substrate), drainage patterns, elevation of floodplain benches, changes in sediment texture across the floodplain, sediment layering, sediment or vegetation deposition, and changes in vegetation communities across the floodplain. The OHWM was marked in the field with flagging hung on vegetation and with pin flags. Flags were only hung in areas with a defined bed and bank, and not in areas where there was little or no defined bank and the channel overflowed on the golf course fairway. For the stream portions that were not flagged, the OHWM will be determined by the elevation of the 2-year storm event that will be modeled for this project. Streams on the site were classified using the Washington State Department of Natural Resources water typing system (WAC 222-16-030), per the Edmonds Community Development Code. This system is based primarily on fish, wildlife, and human use, and consists of four stream types: Type S, F, Np, or Ns (ECDC Chapter 23.90.010). Puget Sound Nearshore The Puget Sound Nearshore is a Washington Department of Fish and Wildlife Priority Habitat that is considered to be the other type of Fish and Wildlife Habitat Conservation Area found within the study area according to the Edmonds Municipal code (ECDC Chapter 23.90.010). They are considered Washington State Department of Fish and Wildlife Priority Habitats (WDFW 2009a). Priority habitats are “those habitat types or elements with unique or significant value to a diverse assemblage of species”, including ESA-listed fish and marine mammals that utilize Puget Sound nearshore areas. Species An assessment of species utilization of Fish and Wildlife Conservation Areas within and adjacent to the study areas was also conducted via review of the reference sources discussed 3 above. This includes species of local importance, priority species, or ESA-listed species that may utilize streams, shoreline areas, and/or their buffers within the study area. 3 No Habitats and Species of Local Importance were identified in addition to State and Federally-protected species in the vicinity of the project area, so they are not discussed further in this report. jr 08-04119-000 talbot critical areas report.doc April 15, 2010 19 Herrera Environmental Consultants Critical Areas Report and Mitigation Plan—Talbot Road – Perrinville Creek Drainage Improvement Frequently Flooded Areas Frequently Flooded Areas within 200 feet of the project area were identified per the requirements specified in ECDC 23.70.010. The portion of the Results section that discusses Frequently Flooded Areas was prepared in accordance with requirements in ECDC 23.70.020. jr 08-04119-000 talbot critical areas report.doc Herrera Environmental Consultants 20 April 15, 2010 Critical Areas Report and Mitigation Plan—Talbot Road – Perrinville Creek Drainage Improvement Results This section discusses the results of the wetland and stream delineation, including a review of information obtained from various references and an analysis of wetland and stream conditions in the study area as observed during field investigations. An assessment of species utilization of Fish and Wildlife Conservation Areas within and adjacent to the study areas was also conducted via review of the reference sources discussed 4 above. This includes species of local importance, priority species, or ESA-listed species that may utilize streams, shoreline areas, and/or their buffers within the study area. Analysis of Wetland Conditions Previously Mapped Wetlands The National Wetlands Inventory indicates the presence of estuarine wetlands along the Puget Sound shoreline to the northwest of the project area (USFWS 1999) (Figure 2). They are identified as estuarine intertidal aquatic bed/unconsolidated shore wetlands under the Cowardin system (Cowardin et al. 1979). The City of Edmonds has identified the historic alluvial fan area of Perrinville Creek (which includes the project area) as a location of “potential wetlands” on their Environmentally Critical Areas Draft Inventory Maps (City of Edmonds 2004). Mapped Soils One soil type, Alderwood-Urban Land Complex, 2 to 8 percent slopes, dominated the project area (NRCS 2009) (Figure 3). The other soil type, Alderwood-Urban Land Complex, 8 to 15 percent slopes, occurs on the southwest portion of 8307 Talbot Road and along the alignment of the proposed stormwater conveyance facilities. McKenna, Norma, and Terric medisaprists are minor soil components within the Alderwood soil type, and they occur in depressional and drainage areas. These soil types are described in the following subsections. Alderwood-Urban Land Complex Alderwood-Urban Land Complex consists of approximately 60 percent Alderwood gravelly sandy loam and about 25 percent urban land. Alderwood soil formed in glacial till, it is moderately deep over a hardpan, and it is moderately well drained (permeability is moderately rapid above the hardpan and very slow through it). A typical soil profile includes a 7-inch surface layer composed of a very dark grayish brown gravelly sandy loam. The upper part of the subsoil is dark yellowish brown and dark brown very gravelly sandy loam about 23 inches thick. The lower portion of the subsoil is an olive brown very gravelly sandy loam about 5 inches thick. 4 No Habitats and Species of Local Importance were identified in addition to State and Federally-protected species in the vicinity of the project area, so they are not discussed further in this report. jr 08-04119-000 talbot critical areas report.doc April 15, 2010 21 Herrera Environmental Consultants Puget Sound Perrinville Creek Unnamed Stream - piped Unnamed Southwest County Stream Park (Snohomish County Parks) LegendFigure 2. National Wetlands Inventory mapped wetlands and streams in the vicinity of the Project area Talbot Road/Perrinville Creek Drainage Improvement Project (USFWS 1999). Stream or ditch (City of Edmonds) Storm water conveyance (City of Edmonds) 0125250500 Feet Estuarine intertidal wetland Aerial Photograph: City of Edmonds (2007) K:\\Projects\\08-04119-000\\Project\\Wetlands_Map.mxd Puget Sound Perrinville Creek Unnamed Stream - piped Unnamed Southwest County Stream Park (Snohomish County Parks) Figure 3. Mapped soils in the vicinity of Alderwood Gravelly sandy loam, Legend 8-15 % slopes the Talbot Road/Perrinville Alderwood Urban land complex, Creek Drainage Improvement Project area 2-8 % slopes Project (NRCS 2009). Alderwood Urban land complex, Stream or ditch 8-15 % slopes Storm water Alderwood-Everett Gravelly sandy conveyance loams, 25-70 0125250500 Soil type (NRCS 2009) Everett gravelly sand loam,Feet Alderwood Gravelly 15-25 % slopes sandy loam, Aerial Photograph: 15-25 % slopes City of Edmonds (2007) K:/Projects/08-04119-000/Projects/Soils_Map.mxd (12/28/2009) JAS Critical Areas Report and Mitigation Plan—Talbot Road – Perrinville Creek Drainage Improvement McKenna Gravelly Silt Loam This soil type is formed in glacial till and it is moderately deep, poorly drained, and it is in depressional areas and drainages on till plains. A typical soil profile consists of an 8-inch surface layer that is very dark grayish brown gravelly silt loam, overlying subsoil that is brown to light olive brown gravelly silt loam about 25 inches thick. Compact glacial till that is olive in color lies below this to a depth of 20 to 40 inches. This soil type occurs on 0 to 8 percent slopes. Norma Loam This soil type is also formed in alluvium, and it is moderately deep, poorly drained, and it is located in depressional areas and drainages on glacial outwash and till plains. A typical soil profile consists of an 10-inch surface layer that is a very dark gray loam, overlying subsoil that is dark grayish brown sandy loam about 18 inches thick. The substratum below this to a depth of 60 inches or more is a dark gray sandy loam. This soil type occurs on 0 to 3 percent slopes. Terric Medisaprists This soil type formed in organic material and alluvium in depressional areas on till plain. It is very deep and very poorly drained. A typical soil profile consists of a 28-inch surface layer that is black and dark brown organic material. The substratum to a depth of 60 inches or more is dark brown to very dark gray very gravelly loamy sand. This soil type occurs on 0 to 3 percent slopes. Wetland Delineation The field activities associated with the wetland delineation were conducted by Herrera biologists Kris Lepine and Crystal Elliot on April 29, 2009. Kris Lepine is a senior biologist with 12 years of experience and is a Professional Wetland Scientist (PWS) (#1514) certified by the Society of Wetland Scientists (SWS). Crystal Elliot is a project biologist with 8 years of experience and is also a PWS (#1936). The weather conditions during the field visit consisted of daytime high temperatures of approximately 60 degrees Fahrenheit (°F), with rainy conditions. Observations were conducted in the growing season, as defined in Appendix B. Herrera biologists delineated one small wetland (Wetland A) at the downstream limits of Perrinville Creek immediately upstream from where the stream enters the culvert underneath the BNSF railroad (Figure 4). The wetland is within the OHWM of Perrinville Creek. A detailed description of Wetland A is provided in Table 1. The biologists completed wetland delineation data forms (Appendix C) and Ecology wetland rating forms (Appendix D) for this wetland. Representative photographs Wetland A are provided in Appendix E. The wetland is located along the left (west) bank of the main channel of the stream, and it is approximately 164 square foot (0.004 acres). Channels on either side of the wetland separate it from the banks of the stream, and main flows appear to shift between these two configurations, depending on channel jr 08-04119-000 talbot critical areas report.doc Herrera Environmental Consultants 24 April 15, 2010 Critical Areas Report and Mitigation Plan—Talbot Road – Perrinville Creek Drainage Improvement Table 1. Summary for Wetland A. Wetland name Wetland A LocationPerrinville Creek Local jurisdiction City of Edmonds WRIA 8 Wetland rating Category III Local jurisdiction 50 buffer width Cowardin Palustrine classification emergent Hydrogeomorphic Riverine classification Wetland data Appendix C, form(s) TP Wet A Upland data form(s) Appendix C, TP UPL A Size of wetland 164 square feet (0.004 acres). Dominant Wetland A is characterized by two distinct vegetation types: (1) the majority of the wetland exhibits vegetation emergent species common in disturbed wetlands in western Washington wetlands, and (2) the southern periphery of the wetland to the northeastern portion is characterized by a substantial hedge of Himalayan blackberry (Rubus armeniacus). The dominant herbaceous vegetation observed in the wetland include creeping buttercup (Ranunculus repens) and bittersweet nightshade (Solanum dulcamara). Soils Soils were examined to at least a 16-inch depth in all test pits and exhibited hydric characteristics. At TP WET 1, the top 6 inches of soil was grayish brown (10YR 5/2) sand. From 6 to 12 inches below the surface, the soil was dark grayish brown (10YR 4/2) sandy loam. From 12 to 16+ inches, the soil was very dark grayish brown (10YR 3/2) silty sand with redoximorphic concentrations (10YR 4/6, 5 percent, in the matrix). This profile meets the criteria for the hydric soil indicator of sandy redox (S5). Hydrology At TP WET 1, soils were saturated to an 8-inch depth. The presence of primary wetland hydrology indicators A2 (Saturation; to 8-inch depth) and B2 (sediment deposits) satisfy the wetland hydrology criteria. Hydrologic inputs to this wetland are driven primarily by surface flow and hyporheic exchange with Perrinville Creek. Rationale for All three wetland parameters are met. delineation Rationale for TheEdmonds Community Development Code (Chapter 23.50) classifies wetlands according to the local rating current Ecology rating system, which rates Wetland A as a Category III. Functions of See narrative below for functions summary. wetland Buffer Buffers surrounding the wetland consist mainly of BNSF railroad prism and right-of-way (upland condition non-native pasture grasses), hardscaped areas (e.g., impervious walkways, decks, etc.), and upland landscaped areas characterized primarily by ornamental small trees, shrubs, and herbaceous species – native vegetation has been cleared throughout the project area. An extensive bamboo hedge is also located to the east of the wetland. The residence at 8307 Talbot Road also has an extensive area of manicured lawn to the southwest of the walkway that lies adjacent to the stream. Existing buffers provide low wildlife habitat and water quality functions, due to the lack of an intact riparian vegetation community. jr 08-04119-000 talbot critical areas report.doc April 15, 2010 27 Herrera Environmental Consultants Critical Areas Report and Mitigation Plan—Talbot Road – Perrinville Creek Drainage Improvement aggradation and subsequent changes to stream morphology. According to Edmonds Community Development Code Chapter 23.50, the wetland is classified as a Category III wetland with a regulated standard buffer width of 50 feet. Evaluation of Wetland Functions Wetland functions for the wetland identified within the project area were evaluated according to Hruby (2004) and supplemental qualitative ratings were determined based on Ecology (2008), and the results are presented in Appendix D. Qualitative and quantitative scores for both potential and opportunity for each wetland to provide water quality, hydrologic, and habitat functions is provided. A total score for the wetland and its corresponding wetland rating category are also provided. Wetland A Wetland A is a small riverine wetland with moderate potential to improve water quality (8 out of 16 points), because it is well vegetated with herbaceous species and it is characterized by some surface depressions, which facilitate filtration of pollutants. It has very high opportunity to improve water quality due to its location downstream of residential areas and heavy landscaping, which results in the discharge of untreated stormwater to this wetland. The wetland has a moderate potential to improve hydrologic functions (8 out of 16 points) because it provides minimal floodwater storage (due to its small size) during flood events on Perrinville Creek, although it is characterized by significant cover of vegetation that may provide some abatement of high water velocities during floods. Wetland A has limited opportunity to reduce flooding and erosion because it is located immediately upstream of Puget Sound, although it may serve a small function in reduction of stream velocities/erosion affecting the BNSF railroad prism. Given the size, lack of structural complexity, amount of disturbance in and around the wetland, and significant presence of invasive species characterizing Wetland A, it provides little habitat value to local wildlife. However, its location within a stream and its proximity to the estuarine wetland habitats associated with Puget Sound provide for a moderate overall habitat function rating (9 out of 18 points). Analysis of Fish and Wildlife Habitat Conservation Area Conditions Streams The two streams located within the project area include Perrinville Creek and an unnamed stream that is a tributary to Perrinville Creek between Talbot Road and the BNSF railroad (although the unnamed tributary is piped throughout the project area). These streams and their buffers are regulated by the City of Edmonds as Fish and Wildlife Conservation Area (ECDC Chapter 23.90). Field investigation and applicable buffer widths for each creek are discussed below. jr 08-04119-000 talbot critical areas report.doc Herrera Environmental Consultants 28 April 15, 2010 Critical Areas Report and Mitigation Plan—Talbot Road – Perrinville Creek Drainage Improvement Perrinville Creek Perrinville Creek originates in the City of Lynnwood, and flows in a northwesterly direction into the City of Edmonds and through Snohomish County Park. Perrinville Creek drains an area of 920 acres: approximately half of its watershed is in Lynnwood and half is in Edmonds. The headwaters of the Perrinville Creek drainage basin include flat to moderate topography with slopes in the range of 0 to 15 percent. The middle reaches of the drainage basin slope more steeply (i.e., often greater than 15 percent) toward Snohomish County Park. The lower portion of the basin is less steeply sloped with the lowest reach of Perrinville Creek located on an alluvial fan. The upper reaches of Perrinville Creek support resident cutthroat trout and the lower reach supports anadromous fish, namely coho salmon (WDFW 2009a). However, a fish barrier (drop culvert) on the downstream side of Talbot Road precludes anadromous fish passage to upper reaches. Downstream of Talbot Road, Perrinville Creek encounters a high-flow bypass (diversion) structure on a city easement adjacent to 8229 Talbot Road. Perrinville Creek then flows across 8235 Talbot Road and enters 8307 Talbot Road from the east. The existing stream channel of Perrinville Creek within the project area lacks quality habitat for anadromous fish that utilize the stream – riparian conditions consist of landscaped vegetation and hardscapes (i.e., paved walkways, decks), and the stream channel lacks complexity and habitat features (e.g., in-channel wood). The streambed lacks morphologic complexity, as it has been modified to allow for the existing residential development, and consequently substrate conditions are relatively homogenous: the streambank through 8235 Talbot Road has been channelized with rip-rap and concrete to a large degree and the boulders have encroached on the channel, On 8307 Talbot Road, nonnative turf species have encroached on the stream channel, and now line a portion of the channel through the property at 8307 Talbot Road. After exiting the property at 8307 Talbot Road and flowing through the BNSF right-of-way, Perrinville Creek is conveyed via a concrete culvert (2.5-foot inner diameter) under the BNSF tracks that run along the Puget Sound shoreline through Edmonds, and then it discharges into Brown’s Bay (Figure 2). The future 100-year and 10-year recurrence peak flows of Perrinville Creek at the culvert under Talbot Road are estimated to be 225 and 112 cfs, respectively (RW Beck 1991), and are expected to be lower in the project area due to the effect of the high-flow bypass. Representative photographs Perrinville Creek within the project area are provided in Appendix E. On April 29, 2009, Herrera biologists Kris Lepine and Crystal Elliot delineated the ordinary high water marks (OHWMs) of the lower reach of Perrinville Creek located between Talbot Road and the inlet of the culvert underneath the BNSF railroad (Figure 4). The OHWMs were marked on each bank with orange pin flags, which were surveyed. This reach of Perrinville Creek is classified as an anadromous fish bearing Type F stream, with a regulated buffer width of 100 feet (ECDC 23.90). A modified Level I stream survey (King County 1991) was performed on December 2, 2009 to characterize habitat conditions within the portion of Perrinville Creek to be affected by the project. The dominant habitat type within this area is a low gradient riffle, with a small area of jr 08-04119-000 talbot critical areas report.doc April 15, 2010 29 Herrera Environmental Consultants Critical Areas Report and Mitigation Plan—Talbot Road – Perrinville Creek Drainage Improvement higher gradient riffle in the BNSF right-of-way and a small plunge pool (maximum depth = 12 inches; average depth = 6 inches; wetted width = 43 inches; length = 106 inches) near the inlet of the culvert conveying Perrinville Creek under the BNSF railroad prism. The average 56 stream channel width is approximately 5 to 8 feet, and the average stream channel depth is approximately 5 to 7 inches. The dominant substrate type throughout this reach was gravel (approximately 2 to 5 cm), with some areas of sand in the BNSF right-of-way and on 8229 Talbot Road, and interspersed cobbles (to 10 cm) being common throughout the project area. Unnamed Stream On March 25, 2009, Herrera biologists investigated portions of the unnamed stream in the project vicinity. Biologists conducted an evaluation of the regulatory status of the open channel of this tributary south of Frederick Place within Snohomish County Park. Through visual observation, it was confirmed that this channel is a stream, pursuant to ECDC Chapter 23.40, because it exhibits a “defined channel or bed which demonstrates clear evidence, such as the sorting of sediments, of the passage of water.” This stream is classified as Type Np, with a regulated buffer width of 50 feet adjacent to open channel segments (ECDC Chapter 23.90). The unnamed stream flows into lower Perrinville Creek approximately 200 feet upstream of its discharge into Puget Sound via the City’s storm drain system (Figure 2). Upstream of its confluence with Perrinville Creek, the unnamed tributary flows through a defined ravine within Snohomish County Park and then enters an 8.5-inch-diameter steel pipe behind the residence at 8302 Frederick Place. From this point, water is piped along Frederick Place. The pipe then daylights within a 20-foot-long ditch; the ditch is connected to a culvert under Frederick Place. The stream daylights for a short segment on the north side of Frederick Place, and then is conveyed through a series of pipes between Fredrick Place and Talbot Road to 8307 Talbot Road, where it discharges through a 12-inch flap gate outfall into Perrinville Creek. The future 100-year and 25-year recurrence peak flows of the unnamed tributary are estimated to be 31 and 20 cfs, respectively, at the outfall to Perrinville Creek. Puget Sound Nearshore The Puget Sound nearshore, a WDFW priority habitat, is located within close proximity to the project area and will also be considered during critical areas review (WDFW 2009a). In this case, this habitat comprises shore, intertidal, and subtidal areas (WDFW 2008). The shore area of this WDFW priority habitat consists of the marine riparian zone, which extends landward from the OHWM to that portion of the terrestrial landscape that is influenced by, or that directly influences, the aquatic ecosystem (WDFW 2008). The construction of the railroad prism has greatly altered the marine riparian zone in this area, and shoreline riparian vegetation is lacking in the vicinity of the project area. The intertidal portion of this priority habitat extends from the 5 Stream channel width was measured from OHWM to OHWM. 6 Stream depth was measured from OHWM elevation to streambed. jr 08-04119-000 talbot critical areas report.doc Herrera Environmental Consultants 30 April 15, 2010 Critical Areas Report and Mitigation Plan—Talbot Road – Perrinville Creek Drainage Improvement OHWM to the extreme lower low water (ELLW). As mentioned, this area is characterized as estuarine intertidal aquatic bed/unconsolidated shore wetlands under the Cowardin system (Cowardin et al. 1979). Intertidal habitats in this location are of particular importance due to their location within the delta of Perrinville Creek and the presence of potential surf smelt and sand lance spawning areas (WDFW 2008, WDFW 2009a). The subtidal portion of this priority habitat extends from ELLW to -30 meters, and the presence of potential forage fish spawning in adjacent intertidal areas renders this habitat also of particular importance (WDFW 2008). Buffers As mentioned, the buffer of Perrinville Creek in the vicinity of the project area has been highly altered due to residential and transportation infrastructure development. Native riparian vegetation has been cleared within the yards of residential homes and within the BNSF railroad right-of-way along the Puget Sound shoreline. Buffers surrounding Perrinville Creek within the project area now consist mainly of BNSF railroad prism and right-of-way areas characterized by upland non-native pasture grasses, hardscaped areas (e.g., impervious walkways, decks, etc.), and upland landscaped areas characterized primarily by ornamental small trees, shrubs, and herbaceous species. An extensive bamboo hedge is also located to the east of the wetland. The residence at 8307 Talbot Road also has an extensive area of manicured lawn to the southwest of the walkway that lies adjacent to Perrinville Creek. The residence at 8235 Talbot Road also has extensive areas of lawn and landscaping. Riparian buffer areas on 8229 Talbot Road have been enhanced to a certain extent via restoration activities within the conservation easement limits (e.g., installation of native trees and shrubs). Some water quality functions are likely performed by buffer areas due to the presence of herbaceous and woody vegetation in landscaped areas. This includes water filtration functions, which is likely important given the input of untreated stormwater and runoff from adjacent landscaped areas (pesticides, herbicides, etc.). However, the presence of impervious surfaces (e.g., rock walkway, decking) immediately adjacent to the stream channel likely compromises some of these functions. Flood storage and hydrologic functions in this area are limited due to the residential setting and altered landscape, lack of native vegetation coverage, and presence of structures and impervious surface. The lack of streamside woody vegetation (i.e., trees and shrubs), which provides numerous functions to the stream environment such as temperature moderation and stormwater abatement, creates a particular limitation on the functionality of the riparian zone of lower Perrinville Creek. Except for a portion of 8229 Talbot Road, buffer areas provide little habitat function for native species (especially anadromous fish) due to their highly altered condition and lack of intact riparian vegetation. Invasive species are also common, including reed canary grass (Phalaris arundinacea) and Himalayan blackberry (Rubus armeniacus). The dominance of ornamental trees and shrubs, significant areas of manicured lawn, strong presence of invasive species, and adjacent hardscaped areas limit habitat value in this area. jr 08-04119-000 talbot critical areas report.doc April 15, 2010 31 Herrera Environmental Consultants Critical Areas Report and Mitigation Plan—Talbot Road – Perrinville Creek Drainage Improvement Fish and Wildlife Species ESA-listed species and habitat information was obtained from the U.S. Fish and Wildlife Service (USFWS) (USFWS 2009a) and the National Oceanic and Atmospheric Administration, National Marine Fisheries Service (NOAA Fisheries 2009). Additional species information was obtained from Priority Habitats and Species data (WDFW 2009a), Washington Department of Natural Resources (WDNR) Natural Heritage program rare plant data (WDNR 2009), and through conversation with the WDFW Area Habitat Biologist (Holser 2009). Wildlife Species The majority of wildlife species that utilize the terrestrial portions of the project area include those species adapted to suburban residential settings with modified vegetation communities and frequent noise and disturbance. Wildlife species that are likely found within the vicinity of the project area at certain times of the year include songbirds, shorebirds, and small mammals. These may include American robin (Turdus migratorius), black-capped chickadee (Poecile atricapillus), English sparrow (Passer domesticus), dark-eyed junco (Junco hyemalis), white- crowned sparrow (Zonotrichia leucophrys), American crow (Corvus brachyrhynchos), ring- billed gull (Larus delawarensis), herring gull (Larus argentatus), and Douglas squirrel (Tamiasciurus douglasii). Aquatic Species Aquatic habitats within the study area are utilized by a myriad of fish species, most of which are limited to the Puget Sound and do not utilize Perrinville Creek. Perrinville Creek does not support any ESA-listed aquatic species: the upper reaches of the stream support resident cutthroat trout and the lower reach (to the fish-impassable culvert at Talbot Road) supports coho salmon (WDFW 2009a; Holser 2009). An area of the Puget Sound shoreline approximately 900 feet to the south of the Perrinville Creek outfall is a documented surf smelt spawning area and virtually the entire shoreline in this area is designated as potential surf smelt and sand lance spawning habitat (WDFW 2009a). Forage fish are an important prey base for a number of ESA-listed species, including marbled murrelets, Chinook salmon, and bull trout. The project will not affect forage fish spawning habitat, because the project is limited to that portion of Perrinville Creek on the south side of the BNSF railroad tracks. Frequently Flooded Areas Frequently flooded areas within 200 feet of the project area were identified per the requirements specified in ECDC 23.70.010, and are depicted on Figure 4 (see below for descriptions of figure features). The lower portion of the project area within the BNSF right-of-way is subject to flooding during instances of extreme high water in Puget Sound. ECDC 23.70.010 states the jr 08-04119-000 talbot critical areas report.doc Herrera Environmental Consultants 32 April 15, 2010 Critical Areas Report and Mitigation Plan—Talbot Road – Perrinville Creek Drainage Improvement requirement of indicating floodplain (100-year flood elevation) and 10- and 50-year flood elevations on project plans to comply with critical areas review requirements. However, it was identified that the latter of these flood level elevation designations are conventional for riverine systems, but not for marine flood areas such as those associated with Puget Sound. In marine settings, the conventional elevations for conveying flood levels are Extreme High Water (EHW) and Mean Higher High Water (MHHW). EHW elevation resembles the highest water level expected in an area. There is no standard return period for this event, but it often equates to the 100-year flood level considering that it is based on water level records which often date back 100 years. The MHHW elevation represents a more ordinary high tide line that is inundated during spring high tides (every 2 weeks). Discussions with the City of Edmonds planning department indicated that the use of the conventional EHW and MHHW in the case of this project (marine environment) would be more appropriate than depicting the 10- and 50-year flood elevations (Lien 2010). jr 08-04119-000 talbot critical areas report.doc April 15, 2010 33 Herrera Environmental Consultants Critical Areas Report and Mitigation Plan—Talbot Road – Perrinville Creek Drainage Improvement Mitigation Plan and Management Recommendations In compliance with the City of Edmonds Community Development Code (ECDC 23.40.120), proposed mitigation measures have been developed to avoid, minimize, or compensate for potential impacts within the wetland and the wetland buffer associated with the proposed project. After it was determined that wetland impacts associated with the proposed project would be unavoidable, a mitigation plan was developed to ensure adequate compensate for loss of wetland function. The objective of mitigation is to achieve equivalent or greater ecologic functions than exist in the affected wetland and buffer area. This mitigation plan was prepared in accordance with ECDC 23.40.130. Mitigation sequencing, proposed mitigation for permanent impacts to the on-site wetland and its buffer resulting from the proposed project, a planting schedule, performance standards, and other required mitigation plan elements are described in the following sections. Mitigation Sequencing Reasonable efforts have been examined to avoid and minimize impacts on critical areas resulting from construction of the proposed project. Alteration to Wetland A and its buffer must be avoided, minimized, or compensated for as outlined by the Washington Administrative Code (WAC 197-11-768) and ECDC 23.40.120, in the following order of preference: Avoid the Impact Due to the location of Wetland A within the Perrinville Creek stream channel in the reach that will be realigned under the proposed project, in addition to constraints associated with engineered channel morphology to achieve fish access requirements, it is not possible to avoid impacts to Wetland A or its buffer. Minimize the Impact Given that the entirety of Wetland A is confined to the stream channel within the reach of Perrinville Creek that will be realigned under the proposed project, minimizing impacts to the wetland will be difficult. However, impacts to the buffer of Wetland A will be minimized to the extent practicable. Incorporation of woody material into the design minimizes fill and provides additional habitat benefits. Impacts will be minimized through implementation of BMPs. As mentioned, all in-channel work associated with the proposed project will occur in dry conditions by diverting all flow through the upstream high-flow bypass structure. Other project BMPs to prevent any suspended jr 08-04119-000 talbot critical areas report.doc April 15, 2010 35 Herrera Environmental Consultants Critical Areas Report and Mitigation Plan—Talbot Road – Perrinville Creek Drainage Improvement sediments from being transported downstream of the project action area and into Puget Sound are described in the Project Description section. Rectify the Impact Impacts associated with relocating the storm drain pipe and outfall will be rectified by restoring the lower reach of Perrinville Creek as described in the Project Description section, including elimination of a fish passage barrier and installing fish habitat structures. Reduce the Impact Impacts will be reduced over time by insuring the success of wetland mitigation and riparian buffer enhancement measures by providing necessary maintenance (see Monitoring, Habitat Management, and Site Maintenance Plan section below). Compensate for Impacts Temporary impacts resulting from the proposed project will be rectified by replanting areas disturbed during construction (Figure 5). Existing shrubs and other vegetation that are removed during construction will be replanted after construction. Lawn areas that are disturbed or removed will be re-seeded or re-sodded. The proposed project will compensate for permanent impacts to Wetland A, Perrinville Creek and their buffers by providing mitigation as described in the following sections (Figure 5). Monitor Mitigation Areas The wetland mitigation and riparian buffer enhancement areas will be monitored for a period of five years after construction as described in the following sections. Wetland Mitigation and Stream Restoration Project activities will result in a permanent impact of 164 square feet of Category III wetland (Figure 6). The replacement ratio for Category III wetlands under City of Edmonds jurisdiction is 2:1, which results in a required mitigation area of at least 328 square feet (ECDC 23.50.050). Approximately 400 feet of riparian floodplain terrace wetland would be restored adjacent to the stream channel of Perrinville Creek (Figure 6). The wetland is designed to receive periodic inundation during the early spring (March through May) and exhibit a high water table (saturation within 12 inches of the soil surface) throughout the remainder of the growing season (through October). jr 08-04119-000 talbot critical areas report.doc Herrera Environmental Consultants 36 April 15, 2010 Critical Areas Report and Mitigation Plan—Talbot Road – Perrinville Creek Drainage Improvement As mentioned, the entire historic alluvial fan of Perrinville Creek is identified as “potential wetland area” by the City of Edmonds, indicating that the likelihood of successfully restoring wetland functions here is high. The presence of minor soil components with hydric properties (e.g., Norma Loam) within the Alderwood map unit that dominates the project area also supports the notion that potential for wetland establishment is high, especially in areas receiving adequate hydrology, such as within the OHWM of Perrinville Creek where this wetland will be located. This mitigation plan follows guidance provided in Restoring Wetlands in Washington (Stevens and Vanbianchi 1993), Wetlands in Washington State, Volume 2: Guidance for Protecting and Managing Wetlands (Granger et al. 2005),in addition to that provided in Ecology’s Coastal Training Program course, Designing Compensatory Mitigation and Restoration Projects (Sheldon 2008). The mitigation approach also makes careful consideration for retention of viewscape properties and salvaging of certain plants of significance to the 8307 Talbot Road property owner. See Table 2 below for a list of plant species recommended for installation in wetland mitigation areas. Table 2. Native plant species planned for installation in proposed wetland mitigation areas for the Talbot Road – Perrinville Creek Drainage Improvement Project. Scientific Name Common Name Carex obnuptaSlough sedge Cornus sericeaRed osier dogwood Lonicera involucrataBlack twinberry Physocarpus capitatusPacific ninebark Rubus spectabilisSalmonberry Salix hookerianaHooker willow Salix lucida ssp. lasiandraPacific willow Salix sitchensisSitka willow Schoenoplectus microcarpus Small-fruited bulrush The City proposes to improve habitat conditions by enhancing a portion of the existing stream channel on the property of the aforementioned address and adjacent BNSF right-of-way with greater habitat complexity that improves fish access and riparian enhancement with planting of native trees and shrubs to provide shade and other currently lacking benefits to fish and wildlife within the stream corridor. The existing channel, with a sharp drop near the culvert inlet on the southwest side of the railroad, is only marginally passable to fish at certain flows. There is also minimal riparian vegetation characterizing the existing stream corridor in this reach, which consists mainly of invasive species (e.g., Himalayan blackberry), non-native grasses in the BNSF right-of-way, ornamental shrubs, and a significant amount of hard-scaped streamside area on the property located at the aforementioned addressed. As mentioned, these conditions will be ameliorated by jr 08-04119-000 talbot critical areas report.doc April 15, 2010 41 Herrera Environmental Consultants Critical Areas Report and Mitigation Plan—Talbot Road – Perrinville Creek Drainage Improvement the construction of fish passable grade control structures constructed of wood and rock, which will result in a series of step pools and extensive plantings following construction. Riparian Buffer Enhancement Although this project is not creating any new buffer impacts that would require buffer mitigation, a riparian buffer enhancement plan will be incorporated into the stream and wetland restoration design to support functions of the riparian zone and wetland areas. As part of Phase 2, a 25-foot 7 zone adjacent to the stream will have native vegetation incorporated in with the existing landscaping as feasible (Figure 6). Areas directly adjacent to stream and wetland areas (within 10 feet) will be planted with only native vegetation. In the upper portion of the project area (8229 Talbot Road), the riparian area will be restored to its previous condition (e.g., re-seeding with grasses as needed; replacing any shrubs/trees damaged by construction activities that were planted in the conservation easement). See Table 3 below for a list of plant species that are planned for installation in wetland and riparian buffer enhancement areas. Table 3. Native plant species planned for installation in proposed riparian buffer enhancement areas for the Talbot Road – Perrinville Creek Drainage Improvement Project. Scientific Name Common Name Acer circinatumVine maple Cornus sericeaRed osier dogwood Corylus cornutaBeaked hazelnut Holodiscus discolorOcean spray Rubus spectabilisSalmonberry Salix sitchensisSitka willow Sambucus racemosaRed elderberr y Symphoricarpos albus Snowberry Given that some portion of the wetland and stream buffer extends onto neighboring properties and onto the BNSF railroad prism, achievement of a 25-foot riparian buffer planting zone is not possible throughout the entire project area, and the proposed enhancement area has been adjusted accordingly. Goals and Objectives Goals and objectives of the aforementioned compensation approach include: 7 Some portion of the riparian buffer extends onto neighboring properties and onto the BNSF railroad prism, requiring adjustment of the proposed enhancement zone due to the fact that these areas can not be modified. jr 08-04119-000 talbot critical areas report.doc Herrera Environmental Consultants 42 April 15, 2010 Critical Areas Report and Mitigation Plan—Talbot Road – Perrinville Creek Drainage Improvement Improving habitat conditions for native fish and wildlife species, particularly anadromous fish in the Perrinville Creek riparian corridor and its buffer, by restoring and enhancing native vegetation community characteristics Successfully establishing wetland mitigation areas to compensate for any functional losses caused by impacts to Wetland A, in terms of water quality functions, hydrologic function, and habitat functions Improving in-stream habitat conditions, including fish access and channel complexity, in the lower reach of Perrinville Creek targeted by the project Performance Standards The performance standards listed below would apply to wetlands and areas within the buffer enhancement area that are planted with native vegetation: Wetland Mitigation Areas Performance Standard 1 100 percent of planted species will survive by the end of the first year after planting. Plants that die will be replaced. Performance Standard 2 By the third year, cover of woody and emergent vegetation will be at least 25 percent. Performance Standard 3 By the fifth year, cover of woody vegetation (shrubs) will be at least 50 percent. Performance Standard 4 The percentage of the wetland mitigation area covered by invasive and non-native species (e.g., Japanese knotweed, reed canarygrass, Himalayan blackberry, English ivy, bittersweet nightshade, bamboo) will not exceed 15 percent throughout the monitoring period. Stream Restoration and Riparian Buffer Enhancement Areas Performance Standard 1 100 percent of planted species will survive by the end of the first year after planting. Plants that die will be replaced. jr 08-04119-000 talbot critical areas report.doc April 15, 2010 43 Herrera Environmental Consultants Critical Areas Report and Mitigation Plan—Talbot Road – Perrinville Creek Drainage Improvement Performance Standard 2 By the third year, cover of woody vegetation (shrubs) will be at least 25 percent. Performance Standard 3 By the fifth year, cover of woody vegetation (shrubs) will be at least 50 percent. Performance Standard 4 The percentage of the buffer enhancement area covered by invasive and non-native species (e.g., Japanese knotweed, reed canarygrass, Himalayan blackberry, English ivy, bittersweet nightshade, bamboo) will not exceed 15 percent throughout the monitoring period. Site Plan – Phase 2 This section describes site preparation and planting activities for the wetland mitigation, stream restoration, and riparian buffer enhancement areas as part of Phase 2. As mentioned, wetland mitigation sites are designed to receive periodic inundation during the early spring (March through May) and exhibit a high water table (saturation within 12 inches of the soil surface) throughout the remainder of the growing season (through October). Desire to achieve this hydrologic regime necessitated a proposed final grade within wetland mitigation areas of 9 inches above the bottom of the stream channel. It is understood that the OHWM will change once stream restoration work has occurred, so it is anticipated that refinement of this grading elevation will be required during construction to ensure desired hydrology is attained. The general construction sequence for construction activities for wetland mitigation, stream restoration, and riparian buffer areas is as follows: 1.Install TESC measures per plans and specifications 2.Site clearing and grubbing per plans and specifications 3.Site grading per plans and specifications 4.Decompact soil (as necessary) to 18-inch depth 5.Apply 3 inches of fine organic compost and till into native soil 6.Install any remaining TESC measures per plans and specifications (e.g., hydroseeding with native seed mix) 7.Install native plant material per plans and specifications jr 08-04119-000 talbot critical areas report.doc Herrera Environmental Consultants 44 April 15, 2010 Critical Areas Report and Mitigation Plan—Talbot Road – Perrinville Creek Drainage Improvement 8.Apply a 4-inch layer of weed-free mulch to entire planting area 9.Install any site protection measures as necessary (e.g., fencing) Earthwork and drainage pipe activities will occur during the summer and fall of 2011 and planting will occur during the dormant, or non-growing, season (November 2011 – February 2012). Once all drainage pipe and stream and wetland earthwork/grading is complete, wetland mitigation areas will be planted with suitable native plant species listed in Table 2. Once non-native plants have been removed and other site work is complete in riparian buffer enhancement areas, appropriate native plant species listed in Table 3 will be installed. The ground surface will be covered with weed-free mulch following plant installation to retain soil moisture and minimize colonization of invasive weeds. 8 Shrubs will be planted 4 feet on-center and emergent species will be planted 1 foot on-center. In terms of plant material, shrubs will be purchased in 1-gallon containers and/or live stake (depending on species and planting location) and emergent species will be purchased in 10-cubic-inch plugs. Effort will be made to incorporate concepts of structural and compositional diversity into planting schemes, including species clustering and encouragement of dense stand and thicket development (WDFW 2009b). Approaches such as these will maximize benefits to the stream environment (e.g., lowering water temperatures via shading, provision of allochthonous nutrients), and provide substantially improved habitat opportunities for local wildlife (e.g., increased foraging potential and refuge). Utilization of native plants also requires less maintenance by the homeowner, as native species are better adapted to local conditions, including water availability and seasonal temperature variation. Monitoring, Habitat Management, and Site Maintenance Plan 9 Monitoring will be conducted for a duration of 5 years. Monitoring reports will be prepared and submitted annually to the City of Edmonds, which will document buffer conditions as compared to performance standards for enhancement success. Maintenance activities will be implemented to ensure that performance standards are met. The following performance standards shall be applied to wetland mitigation areas and riparian buffer enhancement areas: 8 If live stakes are selected for installation on streambanks and in wetland mitigation areas, it is recommended that they be planted 3 feet on center to promote rapid achievement of vegetative cover in these areas. 9 ECDC 23.40.130 states that monitoring and achievement of performance standards are required for a period of no less than 3 years. Herrera Environmental Consultants recommends that this monitoring period be at least 5 years to ensure adequate establishment of installed vegetation and more accurate evaluation of ecosystem function and project success. jr 08-04119-000 talbot critical areas report.doc April 15, 2010 45 Herrera Environmental Consultants Critical Areas Report and Mitigation Plan—Talbot Road – Perrinville Creek Drainage Improvement Monitoring City of Edmonds will arrange for a biologist to perform monitoring of the wetland mitigation and buffer enhancement areas. Monitoring of the buffer enhancement area will be conducted in the first, third, and fifth years following planting to comply with performance standards listed above. The monitoring visit at the end of the first year will be conducted to inspect the plantings, identify mortality, and identify the quantity and locations of plants that need to be replaced (see Performance Standard 1 above). In addition, the entire wetland mitigation and buffer enhancement areas will be inspected for the presence of invasive or exotic plant species (see Performance Standard 4 above). Upon completion of the visit, a memorandum will be prepared for the City of Edmonds Planning Division detailing the results and necessary maintenance measures. City of Edmonds Public Works will verify that the planting contractor appropriately replaces plants that die during the first year. The monitoring visits conducted during the third and fifth years will focus on evaluating the percent cover and invasive species performance standards listed above (see Performance Standards 2, 3, and 4). Upon completion of the site visits, a report will be prepared by a biologist selected by City of Edmonds Public Works with the results and necessary maintenance measures. The report will be submitted to the City of Edmonds Planning Division before the end of each monitoring year. Habitat Management and Site Maintenance Wetlands, Fish and Wildlife Habitat Conservation Areas, and Species This section describes ongoing management and maintenance practices that will improve and protect wetland and riparian functions and habitat value through establishment and maintenance of high vegetation density. Principles of adaptive management, adjusting maintenance and management practices appropriately based on monitoring results, will be applied to ensure maximum project success. Since the existing habitat functions of wetland and stream areas in the vicinity of the project are low to moderate due to alterations to the native vegetation community and current land use practices, the emphasis of this management and maintenance strategy is on enhancement (e.g., increasing vegetative cover). These critical areas will be managed consistent with the best available science, some of which is provided in WDFW’s Wildlife Management Recommendations for Priority Habitat and Species. Recommended planting strategies following these guidelines were provided above. Proposed ongoing management practices that will protect stream and wetland function and habitat value include maintaining the highest vegetative cover possible in wetlands and riparian zones and minimizing the presence of invasive species (WDFW 2009b). During the first year, the planting contractor will be responsible for maintaining 100 percent plant survival within the wetland and in riparian buffer enhancement areas per the planting contract plans. In accordance with the 1-year plant survival guarantee, the contractor will replace plants that have died during the first year. Before plants are replaced, the contractor will consult jr 08-04119-000 talbot critical areas report.doc Herrera Environmental Consultants 46 April 15, 2010 Critical Areas Report and Mitigation Plan—Talbot Road – Perrinville Creek Drainage Improvement with a biologist arranged by City of Edmonds to determine why certain species are not surviving and, if necessary, which native plant substitutions are appropriate. In addition, throughout the summer of the first year, the contractor will be responsible for providing supplemental water as frequently as necessary to ensure healthy plant conditions. The City of Edmonds will be responsible for managing the establishment of plants from the second through the fifth year, with the goal of meeting all applicable performance standards listed above. City of Edmonds Public Works will provide the Planning Division with performance standard results and maintenance recommendations during the first, third, and fifth years after planting. If percent cover requirements for native shrub species are not satisfied, maintenance activities may include, but are not limited to, plant replacement, plant supplement, plant substitution, adjustment of planting layout to reflect specific or changing site conditions, weed control, and installation and adjustment of plant protection devices. For example, if more than 15 percent of the area is invaded by invasive or non-native species, the best method of eradication for the weedy species of concern will be implemented (e.g., herbicide application, weeding, cardboard application). If deemed appropriate by the City of Edmonds, installation of signage per ECDC 23.90.030 may be necessary in the BNSF right of way to indicate the boundary of the riparian buffer enhancement and wetland mitigation areas in order to minimize human impact. Installation of fencing may also be required to protect the functions and values of on-site critical areas, as deemed appropriate by the Planning Division. As this project will not affect the Puget Sound Nearshore, no specific management recommendations for this priority habitat are required as part of this report. In addition, the presence of the BNSF railroad precludes significant improvement of shoreline conditions. However, stream buffer enhancement activities in the BNSF right-of-way (e.g., installation of native tree species) will provide habitat functions for fish and wildlife that utilize the Puget Sound nearshore environment, including salmon and shorebirds. Frequently Flooded Areas 10 Flood capacity related to Puget Sound events will be maintained through proper maintenance of bi-directional flow capacity through the culvert conveying Perrinville Creek under the BNSF railroad prism. This will include periodic inspections of the culvert, especially prior to and following flood events, to ensure that flood-carrying capacity is maintained. The extent of watercourse alteration (as described above in the Project Description) will not affect the flood- carrying capacity associated with this frequently flooded area, as the proposed grading and design actually result in improved drainage and greater flood storage volume than existing conditions. 10 The City of Edmonds Planning Division indicated that the only regulated Frequently Flooded Area affecting the project is associated with Puget Sound high water events. Following, it is only required that this report describe the project’s approach for management of flood capacity related to Puget Sound, and not Perrinville Creek (Lien 2009). jr 08-04119-000 talbot critical areas report.doc April 15, 2010 47 Herrera Environmental Consultants Critical Areas Report and Mitigation Plan—Talbot Road – Perrinville Creek Drainage Improvement Limitations Within the limitations of schedule, budget, and scope-of-work, Herrera Environmental Consultants warrants that this report was conducted in accordance with generally accepted environmental science practices, including technical guidelines and criteria in effect at the time this report was completed. The results and conclusions of this report represent the authors’ best professional judgment, based upon information provided by the project proponent in addition to that obtained during site visits and preparation of the report. No other warranty, expressed or implied, is made. jr 08-04119-000 talbot critical areas report.doc April 15, 2010 49 Herrera Environmental Consultants Critical Areas Report and Mitigation Plan—Talbot Road – Perrinville Creek Drainage Improvement Regulatory Implications Wetland and stream regulations imposed by the federal government and the City of Edmonds will apply to any future activities planned for the project. The filling of wetlands is regulated under the federal Clean Water Act and the Edmonds Community Development Code. The Edmonds Community Development Code also establishes required buffer widths for wetlands and streams. Federal, state, and city regulations require mitigation for impacts on wetlands and streams, and the city also regulates impacts on the buffers of wetlands and streams. Clean Water Act Section 404 Section 404 of the federal Clean Water Act regulates the placement of more than 0.1 acres of fill material in waters of the United States, including wetlands (33 USC 1344). The U.S. Army 11 Corps of Engineers (USACE) administers the permitting program under this law. Such permits include nationwide (general) permits for small areas of fill and individual permits for projects that require larger areas of fill. USACE does not regulate wetland buffers. Section 401 of the Clean Water Act requires that proposed dredge and fill activities permitted under Section 404 be reviewed and certified by Ecology to ensure that the project meets state water quality standards. These regulations will be applicable if any portion of the onsite wetlands are filled or otherwise affected. Edmonds Community Development Code TheEdmonds Community Development Code (Chapter 23.50) requires that wetlands be classified according to the Ecology rating system (Hruby 2004). Buffers are required around each wetland in order to protect the wetland functions and values. For each classification of wetland (Categories I through IV), the code specifies a standard buffer width. This width is then adjusted according to function level and proposed land use impact. As described above, Wetland A meets the criteria for a Category III wetland, and therefore receives a 50-foot buffer per ECDC Chapter 23.50.040. However, ECDC Chapter 23.50.040 states “the standard buffer widths presume the existence of a relatively intact native vegetation community in the buffer zone to adequately protect wetland functions and values at the time of the proposed activity”. If the City determines that the buffer vegetation is inadequate to perform these functions, they may require that the buffer width be increased or they may require the development and implementation of a buffer enhancement plan. Streams are classified under the Fish and Wildlife Habitat Conservation Area section of the Edmonds Community Development Code (Chapter 23.90). Perrinville Creek is classified as a 11 Endangered Species Act (ESA) compliance is required when a Section 404 permit is necessary. jr 08-04119-000 talbot critical areas report.doc April 15, 2010 51 Herrera Environmental Consultants Critical Areas Report and Mitigation Plan—Talbot Road – Perrinville Creek Drainage Improvement Type F stream, because it contains fish habitat. Streams of this rating are required to have a 100-foot-wide buffer measured from each ordinary high water mark (ECDC 23.90.040). The unnamed stream is classified as Type Np, with a regulated buffer width of 50 feet adjacent to open channel segments (ECDC 23.90.040). Permits and approvals that may be necessary from the City of Edmonds include a Land Use Permit, Critical Areas Checklist review, Shorelines permit, and State Environmental Policy Act (SEPA) review. Work within streams or work that affects the flow of streams would require a Hydraulic Project Approval (HPA) from the Washington Department of Fish and Wildlife. jr 08-04119-000 talbot critical areas report.doc Herrera Environmental Consultants 52 April 15, 2010 Critical Areas Report and Mitigation Plan—Talbot Road – Perrinville Creek Drainage Improvement References . A Hydrogeomorphic Classification for Wetlands. Technical Report Brinson, M.M. 1993 WRP-DE-4. U.S. Army Engineer Waterways Experiment Station, Vicksburg, Mississippi. August 1993. City of Edmonds. 2004. Edmonds Community Plan Update 2004. City of Edmonds Environmentally Critical Areas Draft Inventory Maps. Obtained from the City of Edmonds website: http://www.ci.edmonds.wa.us/CityDepartments/PlanningDept/cpupdate_drafts.htm. Accessed on January 5, 2010. Cooke, S. 1997. A Field Guide to the Common Wetland Plants of Western Washington and Northwestern Oregon. Seattle Audubon Society and Washington Native Plant Society, 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. Publication FWS/OBS-79/31. U.S. Department of the Interior, Fish and Wildlife Service, Office of Biological Services. Ecology. 1997. Washington State Wetlands Identification and Delineation Manual. Ecology Publication 96-94. Washington State Department of Ecology. Ecology. 2008. Using the Wetland Rating System in Compensatory Mitigation. Publication 08-06-009. Focus Sheet: Shorelands and Environmental Assistance. Washington State Department of Ecology. Environmental Laboratory. 1987. Corps of Engineers Wetlands Delineation Manual. Technical Report Y-87-1. U.S. Army Corps of Engineers, Waterways Experiment Station, Vicksburg, Mississippi. Environmental Laboratory. 2008. Interim Regional Supplement to the Corps of Engineers Wetlands Delineation Manual: Western Mountains, Valleys, and Coast Region. Technical Report TR-08-13. U.S. Army Corps of Engineers, Engineer Research and Development Center, Wetlands Regulatory Assistance Program, Vicksburg, Mississippi. Foley, Steve. 2008. Personal communication (phone call with Kris Lepine, Herrera Environmental Consultants, Inc., Seattle, Washington, regarding salmonid presence in Panther Creek). Fish Biologist, WDFW, Mill Creek, Washington. July 29, 2008. Google Maps. 2009. High resolution aerial photographs of Talbot Road – Perrinville Creek project area, Edmonds, Washington. Website accessed on November 1, 2009. Available at: http://maps.google.com. jr 08-04119-000 talbot critical areas report.doc April 15, 2010 53 Herrera Environmental Consultants Critical Areas Report and Mitigation Plan—Talbot Road – Perrinville Creek Drainage Improvement Granger, T., T. Hruby, A. MacMillan, D. Peters, J. Rubey, D. Sheldon, S. Stanley, E. Stockdale. April 2005. Wetlands in Washington State – Volume 2: Guidance for Protecting and Managing Wetlands. Washington State Department of Ecology. Publication #05-06-008. Olympia, Washington. Hitchcock, C.L. and A. Cronquist. 1987. Flora of the Pacific Northwest. University of Washington Press, Seattle, Washington. Holser, G. 2009. Personal communication (discussion during site visit with Crystal Elliot, Herrera Environmental Consultants, Inc., Seattle, Washington, regarding the presence of priority species in the project area). WDFW Area Habitat Biologist. March 25, 2009. Hruby, T. 2004. Washington State Wetland Rating System for Western Washington—Revised. Ecology Publication 04-06-025. August 2004. Washington State Department of Ecology. Obtained February 4, 2009, from agency website: http://www.ecy.wa.gov/pubs/0406025.pdf. King County. 1991. Stream Survey Report Criteria for Level I Surveys. Department of Parks, Planning, and Resources, Building and Land Development Division. Lien, Kernen. 2010. Personal communication (phone conversation with Crystal Elliot, Herrera Environmental Consultants, regarding Frequently Flooded Areas compliance). January 6, 2010. Munsell Color. 2000. Munsell Soil Color Charts. New Windsor, New York. NOAA Fisheries. 2009. Species lists for Puget Sound, (West Coast Salmon and Steelhead list updated July 1, 2009; Marine Mammals list accessed on 10/20/09). Obtained from agency website on October 20, 2009: http://www.nwr.noaa.gov/Species-Lists.cfm. National Oceanic and Atmospheric Administration, National Marine Fisheries Service, Northwest Regional Office, Seattle, Washington. NOAA. 2010. National Oceanic and Atmospheric Administration, Tides and Currents webpage. Obtained January 8, 2010, from website: http://tidesandcurrents.noaa.gov/. NRCS. 2006. Field Indicators of Hydric Soils in the United States. Version 6.0. G.W. Hurt and L.M. Vasilas (eds.). U.S. Department of Agriculture, Natural Resources Conservation Service, in association with the National Technical Committee for Hydric Soils. NRCS. 2009a. The PLANTS Database. U.S. Department of Agriculture, Natural Resources Conservation Service, National Plant Data Center, Baton Rouge, Louisiana. Obtained February 25, 2009, from agency website: http://plants.usda.gov. NRCS. 2009b. Web Soil Survey, National Cooperative Soil Survey. Snohomish County area, Washington. Version 6. Natural Resources Conservation Service. September 22, 2009. jr 08-04119-000 talbot critical areas report.doc Herrera Environmental Consultants 54 April 15, 2010 Critical Areas Report and Mitigation Plan—Talbot Road – Perrinville Creek Drainage Improvement NRCS. 2009c. National hydric soils list for the state of Washington. January 2009. U.S. Department of Agriculture, Natural Resources Conservation Service. Obtained February 25, 2009, from agency FTP site: ftp://ftp- fc.sc.egov.usda.gov/NSSC/Hydric_Soils/Lists/hydric_soils_3.xls. R.W. Beck. 1991. Edmonds drainage basin studies: Edmonds Way, Perrinville, and Meadowdale Basins. Unpublished report by R.W. Beck and Associates Inc., Seattle, Washington. Reed, P.B. 1988. National list of plant species that occur in wetlands: Washington. Biological Report 88(26.9) for National Wetlands Inventory, Washington, D.C. Reed, P.B. 1993. Northwest supplement (Region 9) species with a change in indicator status or added to the northwest 1988 list, wetland plants of the state of Washington 1988. Biological Report 88 (26.9), for National Wetlands Inventory, Washington, D.C. Rieman, B.E. and J.D. McIntyre. 1993. Demographic and Habitat Requirements for Conservation of Bull Trout. In: General Technical Report INT-302. U.S. Department of Agriculture, U.S. Forest Service, Intermountain Forest and Range Experiment Station. SCS. 1983. Soil Survey of Snohomish County Area, Washington. U.S. Department of Agriculture, Soil Conservation Service. Published July 1983. Sheldon, D. 2008. Designing Compensatory Mitigation and Restoration Projects, Washington State Department of Ecology Coastal Training Program course, November 2008. Olympia, Washington. Shuster, J. 2010. Personal communication (email between Jerry Shuster, City of Edmonds, and Arthur Fleming, Herrera Environmental Consultants, Inc., Seattle, Washington, regarding riparian buffer width). March 29, 2010. Stevens, M.L. and R. Vanbianchi. 1993. Restoring Wetlands in Washington. Publication #93-17. Washington State Department of Ecology, Olympia, Washington. USFWS. 1993. 1993 Northwest Region 9 Supplement to the National List of Plant Species that Occur in Wetlands. Combined 1988 national list and 1993 supplement. U.S. Department of Interior, Fish and Wildlife Service. USFWS. 1999. Raster scan data of National Wetlands Inventory wetlands maps. Digital data created in 1999. U.S. Fish and Wildlife Service. Obtained on February 10, 2003, from agency website: http://wetlandswms.er.usgs.gov/imf/imf.jsp?site=extract_tool. USFWS. 2009a. Listed and Proposed Endangered and Threatened Species and Critical Habitat; Candidate Species; and Species of Concern in Snohomish County, Washington. U.S. Fish and Wildlife Service, Western Washington Fish and Wildlife Office. Obtained on October 21, 2009 from agency website: http://www.fws.gov/westwafwo/speciesmap. jr 08-04119-000 talbot critical areas report.doc April 15, 2010 55 Herrera Environmental Consultants Critical Areas Report and Mitigation Plan—Talbot Road – Perrinville Creek Drainage Improvement WDFW. 2008. Priority Habitat and Species List. Washington Department of Fish and Wildlife. Olympia, Washington. 174 pp. WDFW. 2009a. Priority habitat and species maps for the Talbot Road-Perrinville Creek Drainage Improvement project. Washington Department of Fish and Wildlife, Olympia, Washington. WDFW. 2009b. Washington State Department of Fish and Wildlife, Landscape Planning for Washington’s Wildlife: Managing Biodiversity in Developing Areas. Washington Department of Fish and Wildlife, Olympia, Washington. 88 pp. WDNR. 2009. Washington Natural Heritage Information System List of Known Occurrences of Rare Plants in Washington, February 2009, Snohomish County. Washington State Department of Natural Resources. Obtained from agency website on October 21, 2009: http://www1.dnr.wa.gov/nhp/refdesk/lists/plantsxco/snohomish.html. WSDOT. 2009. WSDOT Fish Exclusion Protocols and Standards. Washington Department of Transportation. June 25, 2009. jr 08-04119-000 talbot critical areas report.doc Herrera Environmental Consultants 56 April 15, 2010 APPENDIX A Construction Drawings APPENDIX B Wetland Delineation Methods Critical Areas Report and Mitigation Plan—Talbot Road – Perrinville Creek Drainage Improvement Wetland Delineation Methods This wetland delineation was performed in accordance with the Washington State Wetlands Identification and Delineation Manual (Ecology 1997) and the Interim Regional Supplement to the Corps of Engineers Wetlands Delineation Manual: Western Mountains, Valleys, and Coast Region(Environmental Laboratory 2008), both of which are consistent with the 1987 Corps of Engineers Wetlands Delineation Manual (Environmental Laboratory 1987). These methods use a three-parameter approach for identifying and delineating wetlands. This approach is based on the presence of field indicators for hydrophytic vegetation, hydric soils, and hydrology. This wetland delineation was performed according to procedures specified for the routine wetland determination method (Ecology 1997). Hydrophytic Vegetation Hydrophytic vegetation is characterized by the ability to grow, effectively compete, reproduce, and persist in anaerobic soil conditions that have resulted from periodic or long-term saturation. Numerous field indicators of hydrophytic vegetation may be used, although the most common indicator is defined as more than 50 percent of the dominant species in each vegetation stratum having a wetland indicator status of obligate wetland (OBL), facultative wetland (FACW), or facultative (FAC). The plant indicator status categories are explained in Table A-1. Table A-1. Plant indicator status categories. Indicator Indicator Status Symbol Definition Obligate wetland plants OBL Plants that occur almost always (estimated probability >99%) in wetlands under natural conditions but also occur rarely (estimated probability <1%) in upland areas Facultative wetland plants FACWPlants that usually occur (estimated probability >67%) in wetlands under natural conditions but also occur (estimated probability 1% to 33%) in upland areas Facultative plants FACPlants with a similar likelihood (estimated probability 33% to 67%) of occurring in both wetlands and upland areas Facultative upland plants FACU Plants that sometimes occur (estimated probability 1% to 33%) in wetlands but occur more often (estimated probability >67% to 99%) in upland areas Obligate upland plants UPL Plants that rarely occur (estimated probability <1%) in wetlands under natural conditions WETDRY OBLFAC WFACFACUUPL Source: Environmental Laboratory (1987). Dominant species are those that contribute more than other species to the character of a plant community. To determine dominance, first a complete list of plant species that occur in the sampling area is compiled and divided into four strata: tree, sapling/shrub, herb, and woody vine. Next, a vegetation sampling plot is determined by the field biologist to accurately lt o:\\proj\\y2008\\08-04119-000\\word processing\\reports\\critical areas report\\appendix\\appendix b - wetland delineation methods\\08-04119-000 appendix b-delineation methods.doc January 19, 2010 B-1 Herrera Environmental Consultants Critical Areas Report and Mitigation Plan—Talbot Road – Perrinville Creek Drainage Improvement characterize the plant community in the area to be evaluated. These sampling plots are typically circular areas that are centered on the location of the test pit (used to sample soils). The radius of the circle is determined in the field on the basis of site conditions. In large wetlands, a typical sampling radius would be 2 to 5 meters for tree and sapling/shrub species and 1 meter for herbaceous species. In a small or narrow wetland (or upland area), the radius might be reduced to accurately sample wetland (upland) areas and avoid overlapping an adjacent community with different vegetation, soils, or hydrologic conditions (Environmental Laboratory 2008). A plant is included in the tree stratum if it is a woody plant with a diameter at breast height (dbh) of at least 3 inches; in the sapling/shrub stratum if it is a woody plant less than 3 inches dbh; in the herb stratum if it is an herbaceous (nonwoody) plant; and in the woody vine stratum if it is a woody vine of any height (Environmental Laboratory 2008). To be included in the sampling, 50 percent or more of the plant base must be within the radius of the sampling plot. For a tree to be included, more than 50 percent of the trunk (diameter) must be within the sampling radius. For each sampling plot, the plant species within each stratum are listed on the wetland determination data form, in decreasing order of their areal coverage. Starting with the plant species at the top of the stratum list (the highest percentage of coverage) and proceeding down the list (in descending order of coverage), the percentages are cumulatively totaled until the sum reaches 50 percent. The plant species that constitute this first 50 percent of areal coverage are considered the dominant species in the stratum. In addition, a plant species that constitutes 20 percent or more of the areal coverage in the stratum is also considered a dominant species (Environmental Laboratory 1987). The wetland determination data form includes this dominance test and the prevalence test for assessing whether the criteria for hydrophytic vegetation are met at each sampling plot (Environmental Laboratory 2008). Plant species were identified using Flora of the Pacific Northwest (Hitchcock and Cronquist 1987) and A Field Guide to the Common Wetland Plants of Western Washington and Northwestern Oregon (Cooke 1997). The indicator status of each plant species is based on a list of plant species that occur in wetlands in the Pacific Northwest (USFWS 1993). Biologists referred to the national Plants Database produced by the U.S. Department of Agriculture (NRCS 2009a) to determine whether the scientific names of plants have changed since the publication of the national list of plant species that occur in wetlands (Reed 1988, 1993); any name changes were noted according to the Plants Database. Other evidence of hydrophytic vegetation includes observation of plant species growing in areas of prolonged inundation or soil saturation, and visual evidence of physiological, morphological, or reproductive adaptations. The section in the supplement to the Corps of Engineers manual that discusses problematic hydrophytic vegetation further explains how to interpret these situations (Environmental Laboratory 2008). Hydric Soils A hydric soil is a soil that is saturated, flooded, or inundated long enough during the growing season to develop anaerobic conditions that favor the growth and regeneration of hydrophytic lt o:\\proj\\y2008\\08-04119-000\\word processing\\reports\\critical areas report\\appendix\\appendix b - wetland delineation methods\\08-04119-000 appendix b-delineation methods.doc Herrera Environmental Consultants B-2 January 19, 2010 Critical Areas Report and Mitigation Plan—Talbot Road – Perrinville Creek Drainage Improvement vegetation (SCS 1988). Hydric soils data were obtained by digging test pits at least 20 inches deep and 4 inches wide. Hydric soil conditions were evaluated using indicators outlined in Field Indicators of Hydric Soils in the United States (NRCS 2006) and adopted by the Interim Regional Supplement to the Corps of Engineers Wetlands Delineation Manual: Western Mountains, Valleys, and Coast . Region(Environmental Laboratory 2008) These indicators are divided into three groups: all soils, sandy soils, and loamy and clayey soils. The “all soils” indicators can apply to any soil, regardless of texture; the “sandy soils” indicators are used in soil layers with textures of loamy fine sand or coarser; the “loamy and clayey soils” indicators are used for soil layers of loamy very fine sand and finer. Hydric soil indicators applicable to the Western Mountains, Valleys, and Coast region include but are not limited to the presence of organic soils (i.e., histosols or histic epipedons), sulfidic material (i.e., hydrogen sulfide), depleted, gleyed, or reduced soil matrices, the presence of iron or manganese concretions, and color (Environmental Laboratory 2008). Soil color (i.e., hue, value, and chroma) was evaluated using Munsell Soil Color Charts (Munsell Color 2000). Hydric soils were further confirmed by verifying their inclusion on the hydric soils list (NRCS 2009b). Wetland Hydrology Wetland hydrology is indicated by soils that are periodically inundated or saturated to the surface for a sufficient duration during the growing season. A sufficient duration is defined as at least 12.5 percent of the total growing season days that are consecutively inundated or saturated to the surface. The growing season is the period of consecutive frost-free days or the longest period during which the soil temperature stays above biological zero (41 degrees Fahrenheit \[F\]) at 12 inches below the surface. As a general rule, the growing season for western Washington lowlands consists of 245 days, extending from March 1 to October 31 (Ecology 1997). Therefore, a sufficient duration of inundation would be a minimum of 31 days. Two indicators of biological activity can be used to determine whether the growing season has begun and is ongoing (Environmental Laboratory 2008). The first indicator is the occurrence of aboveground growth and development of at least two nonevergreen vascular plant species within the wetland. Examples of this growth include the emergence or elongation of leaves on woody plants and the emergence or opening of flowers. The second indicator is soil temperature of at least 41F at a depth of 12 inches, which can be measured once during a single site visit. For this wetland delineation, hydrologic indicators were examined within the soil test pits in the field. Hydrologic indicators include the presence of surface water, standing water in the test pit at a depth of 12 inches or less, saturation in the root zone, watermarks, drift lines, sediment deposits, drainage patterns within wetlands, oxidized rhizospheres surrounding living roots, and water-stained leaves. lt o:\\proj\\y2008\\08-04119-000\\word processing\\reports\\critical areas report\\appendix\\appendix b - wetland delineation methods\\08-04119-000 appendix b-delineation methods.doc January 19, 2010 B-3 Herrera Environmental Consultants APPENDIX C Wetland Delineation Data Forms WETLAND DETERMINATION DATA FORM – Western Mountains, Valleys, and Coast Region Project Site: Talbot Road/Perrinville Creek City/County: Edmonds Sampling Date: 4/29/09 Applicant/Owner: City of Edmonds State: WA Sampling Point: UPL 1 Investigator(s): K. Lepine and C. Elliot Section, Township, Range: T27N,R4E,S7 Landform (hillslope, terrace, etc.): Relic shoreline terrace Local relief (concave, convex, none): Slightly concave Slope (%):0 Subregion (LRR): LRR A Lat: Long: Datum: Soil Map Unit Name: NWI classification: none Are climatic / hydrologic conditions on the site typical for this time of year? Yes No (If no, explain in Remarks.) Are Vegetation , Soil , Or Hydrology , significantly disturbed? Are “Normal Circumstances” present? Yes No Are Vegetation , Soil , Or Hydrology , naturally problematic? (If needed, explain any answers in Remarks.) SUMMARY OF FINDINGS – Attach site map showing sampling point locations, transects, important features, etc. Hydrophytic Vegetation Present? Yes No Hydric Soil Present? Yes No Is the Sampled Area within a Wetland? YES NO Wetland Hydrology Present? Yes No Remarks: None of the three wetland parameters were met. This is not a USCOE jurisdictional wetland. VEGETATION – Use scientific names of plants Absolute DominantIndicator Tree Stratum (Plot Size: )Dominance Test Worksheet: % CoverSpecies?Status 1. Number of Dominant Species That Are 2 (A) OBL, FACW, or FAC: 2. 3. Total Number of Dominant Species Across 4 (B) All Strata: 4. = Total Cover Percent of Dominant Species That Are 50% (A/B) OBL, FACW, or FAC: Sapling/Shrub Stratum (Plot Size: 2m) 1. Rubus laciniatus 5 Yes FACU+ Prevalence Index worksheet: 2. Total % Cover of: Multiply by: 3. OBL species x1 = 4. FACW species x2 = 5. FAC species x3 = 5 = Total Cover FACU species x4 = Herb Stratum (Plot Size: 1m) UPL species x5 = 1. Festuca arundinacea 50 Yes FAC- (A) (B) Column Totals: 2. Poa pratensis50 Yes FAC Prevalence Index = B/A = 3. Cirsium arvense 30 Yes FACU+ Hydrophytic Vegetation Indicators: 4. Galium aparine 10 No FACU yes Dominance Test is >50% 5. 1 Prevalence Index is <3.0 6. 1 Morphological Adaptations (Provide supporting data in Remarks or on a separate sheet) 7. 1 8. Wetland Non-Vascular Plants 9. 1 (Explain) Problematic Hydrophytic Vegetation 10. 11. 1 Indicators of hydric soil and wetland hydrology must be present, unless disturbed or problematic. 140 = Total Cover Woody Vine Stratum (Plot Size: ) 1. Hydrophytic Vegetation Yes No 2. Present? = Total Cover % Bare Ground in Herb Stratum = 0 Remarks: Only 50% of the observed dominant vegetation is hydrophytic. Vegetation appears to be mown on a regular basis – BNSF right-of way. US Army Corps of Engineers Western Mountains, Valley, and Coast – Interim Version lt talbot_upl 1_corps data form.doc Project Site: Talbot Road/Perrinville Creek SOIL Sampling Point: UPL 1 Profile Description: (Describe to the depth needed to document the indicator or confirm the absence of indicators.) Depth Matrix Redox Features ColorColor 12 (inches) %% Type Loc Texture Remarks (moist) (Moist) 0-5 10YR 3/3 100 Sandy loam 5-8 10YR 4/3 100 Loamy sand 8-18 10YR 3/2 100 Gravelly sandy laom 12 Type: C= Concentration, D=Depletion, RM=Reduced Matrix, CS=Covered or Coated Sand Grains. Location: PL=Pore Lining, M=Matrix 3 Hydric Soil Indicators: (Applicable to all LRRs, unless otherwise noted.) Indicators for Problematic Hydric Soils: Histosol (A1) Sandy Redox (S5) 2 cm Muck (A10) Histic Epipedon (A2) Stripped Matrix (S6) Red Parent Material (TF2) Black Histic (A3) Loamy Mucky Mineral (F1) (except MLRA 1) Other (Explain in Remarks) Hydrogen Sulfide (A4) Loamy Gleyed Matrix (F2) Depleted Below Dark Surface (A11) Depleted Matrix (F3) Thick Dark Surface (A12) Redox Dark Surface (F6) 3 Indicators of hydrophytic vegetation and wetland Sandy Mucky Mineral (S1) Depleted Dark Surface (F7) hydrology must be present, unless disturbed or Sandy Gleyed Matrix (S4) Redox Depressions (F8) problematic. Restrictive Layer (if present): Hydric Soil Present? YesNo Type: Depth (inches): Remarks: None of the field indicators for hydric soils were observed in test pit. HYDROLOGY Wetland Hydrology Indicators: Primary Indicators (minimum of one required; check all that apply) Secondary Indicators (2 or more required) Surface Water (A1) Water-Stained Leaves (B9) Water-Stained Leaves (B9) High Water Table (A2) (except MLRA 1, 2, 4A, and 4B) (MLRA 1, 2, 4A, and 4B) Saturation (A3) Salt Crust (B11) Drainage Patterns (B10) Water Marks (B1) Aquatic Invertebrates (B13) Dry-Season Water Table (C2) Sediment Deposits (B2) Hydrogen Sulfide Odor (C1) Saturation Visible on Aerial Imagery (C9) Drift Deposits (B3) Oxidized Rhizospheres along Living Roots (C3) Geomorphic Position (D2) Algal Mat or Crust (B4) Presence of Reduced Iron (C4) Shallow Aquitard (D3) Iron Deposits (B5) Recent Iron Reduction in Tilled Soils (C6) FAC-Neutral Test (D5) Surface Soil Cracks (B6) Stunted or Stresses Plants (D1) (LRR A) Raised Ant Mounds (D6) (LRR A) Inundation Visible on Aerial Imagery (B7) Other (Explain in Remarks) Frost-Heave Hummocks (D7) Sparsely Vegetated Concave Surface (B8) Field Observations: Surface Water Present? Yes No Depth (inches): - Water Table Present? Yes No Depth (inches): - Wetland Hydrology Present? Yes No Saturation Present? Yes No Depth (inches): - (includes capillary fringe) Describe Recorded Data (stream gauge, monitoring well, aerial photos, previous inspections), if available: Remarks:None of the field indicators for wetland hydrology were observed in test pit. US Army Corps of Engineers Western Mountains, Valley, and Coast – Interim Version lt talbot_upl 1_corps data form.doc WETLAND DETERMINATION DATA FORM – Western Mountains, Valleys, and Coast Region Project Site: Talbot Road/Perrinville Creek City/County: Edmonds Sampling Date: 4/29/09 Applicant/Owner: City of Edmonds State: WA Sampling Point: WET 1 Investigator(s): K. Lepine and C. Elliot Section, Township, Range: T27N,R4E,S7 Landform (hillslope, terrace, etc.): Island within stream channel Local relief (concave, convex, none): none Slope (%):5% Subregion (LRR): LRR A Lat: Long: Datum: Soil Map Unit Name: NWI classification: none Are climatic / hydrologic conditions on the site typical for this time of year? Yes No (If no, explain in Remarks.) Are Vegetation , Soil , Or Hydrology , significantly disturbed? Are “Normal Circumstances” present? Yes No Are Vegetation , Soil , Or Hydrology , naturally problematic? (If needed, explain any answers in Remarks.) SUMMARY OF FINDINGS – Attach site map showing sampling point locations, transects, important features, etc. Hydrophytic Vegetation Present? Yes No Hydric Soil Present? Yes No Is the Sampled Area within a Wetland? YES NO Wetland Hydrology Present? Yes No Remarks: Positive indicators present for all three wetland parameters. This is a USCOE jurisdictional wetland. VEGETATION – Use scientific names of plants Absolute DominantIndicator Tree Stratum (Plot Size: )Dominance Test Worksheet: % CoverSpecies?Status 1. Number of Dominant Species That Are 2 (A) OBL, FACW, or FAC: 2. 3. Total Number of Dominant Species Across 3 (B) All Strata: 4. = Total Cover Percent of Dominant Species That Are 66.6% (A/B) OBL, FACW, or FAC: Sapling/Shrub Stratum (Plot Size: 2m) 1. Rubus armeniacus 5 Yes FACU Prevalence Index worksheet: 2. Total % Cover of: Multiply by: 3. OBL species x1 = 4. FACW species x2 = 5. FAC species x3 = 5 = Total Cover FACU species x4 = Herb Stratum (Plot Size: 1m) UPL species x5 = 1. Ranunculus repens 80 Yes FACW (A) (B) Column Totals: 2. Solanum dulcamara 25 Yes FAC+ Prevalence Index = B/A = 3. Veronica anagallis-aquatica 5 No OBL Hydrophytic Vegetation Indicators: 4. Galium aparine 2 No FACU yes Dominance Test is >50% 5. Rorippa nasturtium-aquaticum 2 NO OBL 1 Prevalence Index is <3.0 6. 1 Morphological Adaptations (Provide supporting data in Remarks or on a separate sheet) 7. 1 8. Wetland Non-Vascular Plants 9. 1 (Explain) Problematic Hydrophytic Vegetation 10. 11. 1 Indicators of hydric soil and wetland hydrology must be present, unless disturbed or problematic. 114 = Total Cover Woody Vine Stratum (Plot Size: ) 1. Hydrophytic Vegetation Yes No 2. Present? = Total Cover % Bare Ground in Herb Stratum = 0 Remarks: Over 50% of the observed dominant vegetation is hydrophytic (66.6% observed). US Army Corps of Engineers Western Mountains, Valley, and Coast – Interim Version lt talbot_wet 1_corps data form.doc Project Site: Talbot Road/Perrinville Creek SOIL Sampling Point: WET 1 Profile Description: (Describe to the depth needed to document the indicator or confirm the absence of indicators.) Depth Matrix Redox Features ColorColor 12 (inches) %% Type Loc Texture Remarks (moist) (Moist) 0-6 10YR 5/2 100 - - - - Sand 6-12 10YR 4/2 100 - - - - Sandy loam 12-18 10YR 3/2 95 10YR 4/6 5 C M Slity sand 12 Type: C= Concentration, D=Depletion, RM=Reduced Matrix, CS=Covered or Coated Sand Grains. Location: PL=Pore Lining, M=Matrix 3 Hydric Soil Indicators: (Applicable to all LRRs, unless otherwise noted.) Indicators for Problematic Hydric Soils: Histosol (A1) Sandy Redox (S5) 2 cm Muck (A10) Histic Epipedon (A2) Stripped Matrix (S6) Red Parent Material (TF2) Black Histic (A3) Loamy Mucky Mineral (F1) (except MLRA 1) Other (Explain in Remarks) Hydrogen Sulfide (A4) Loamy Gleyed Matrix (F2) Depleted Below Dark Surface (A11) Depleted Matrix (F3) Thick Dark Surface (A12) Redox Dark Surface (F6) 3 Indicators of hydrophytic vegetation and wetland Sandy Mucky Mineral (S1) Depleted Dark Surface (F7) hydrology must be present, unless disturbed or Sandy Gleyed Matrix (S4) Redox Depressions (F8) problematic. Restrictive Layer (if present): Hydric Soil Present? YesNo Type: Depth (inches): Remarks: Hydric soil indicator S5 (Sandy Redox) observed in test pit. HYDROLOGY Wetland Hydrology Indicators: Primary Indicators (minimum of one required; check all that apply) Secondary Indicators (2 or more required) Surface Water (A1) Water-Stained Leaves (B9) Water-Stained Leaves (B9) High Water Table (A2) (except MLRA 1, 2, 4A, and 4B) (MLRA 1, 2, 4A, and 4B) Saturation (A3) Salt Crust (B11) Drainage Patterns (B10) Water Marks (B1) Aquatic Invertebrates (B13) Dry-Season Water Table (C2) Sediment Deposits (B2) Hydrogen Sulfide Odor (C1) Saturation Visible on Aerial Imagery (C9) Drift Deposits (B3) Oxidized Rhizospheres along Living Roots (C3) Geomorphic Position (D2) Algal Mat or Crust (B4) Presence of Reduced Iron (C4) Shallow Aquitard (D3) Iron Deposits (B5) Recent Iron Reduction in Tilled Soils (C6) FAC-Neutral Test (D5) Surface Soil Cracks (B6) Stunted or Stresses Plants (D1) (LRR A) Raised Ant Mounds (D6) (LRR A) Inundation Visible on Aerial Imagery (B7) Other (Explain in Remarks) Frost-Heave Hummocks (D7) Sparsely Vegetated Concave Surface (B8) Field Observations: Surface Water Present? Yes No Depth (inches): - Water Table Present? Yes No Depth (inches): - Wetland Hydrology Present? Yes No Saturation Present? Yes No Depth (inches): 8 (includes capillary fringe) Describe Recorded Data (stream gauge, monitoring well, aerial photos, previous inspections), if available: Remarks:Primary wetland hydrology indicators A2 – Saturation (to 8” depth) and B2 – Sediment Deposits observed in test pit. US Army Corps of Engineers Western Mountains, Valley, and Coast – Interim Version lt talbot_wet 1_corps data form.doc APPENDIX D Wetland Rating Forms WET 1 Wetland name or number: 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):Talbot Road/Perrinville CreekDate of site visit: 4/29/09 Rated byYes No Date:5/1/08 Trained by Ecology? C. Elliot SEC:7TWNSHP:27NRNGE:4EIs S/T/R in Appendix D? Yes No Map of wetland unit:Estimated size:Figure SUMMARY OF RATING Category based on FUNCTIONS provided by wetland IIIIIIIV Category I = Score >=70Score for Water Quality Functions16 Category II = Score 51-69Score for Hydrologic Functions8 Category III = Score 30-50Score for Habitat Functions9 TOTAL score for functions33 Category IV = Score <30 Category based on SPECIAL CHARACTERISTICS of wetland IIIDoes not Apply Final Category III (choose the "highest" category from above) Check the appropriate type and class of wetland being rated. Wetland TypeWetland Class EstuarineDepressional Natural Heritage WetlandRiverine BogLake-fringe Mature ForestSlope Old Growth ForestFlats Coastal LagoonFreshwater Tidal Interdunal None of the above Check if multiple HGM classes are present Comments: Wetland Rating Form - Western Washington 1 Herrera Environmental Consultants, Inc. Does the wetland unit being rated meet any of the criteria below? If you answer YES to any of the questions below, you will need to protect the wetland according to the regulations regarding the special characteristics found in the wetland. Check List for Wetlands That May Need Special Protection (in addition to the YESNO protection recommended for its category) Has the wetland unit been documented as a habitat for any federally listed SP1. plant or animal Threatened or Endangered (T/E) species? For the purposes of this rating system, "documented" means the wetland is on the appropriate state or federal database. Has the wetland unit been documented as habitat for any state listed Threatened SP2. animal or Endangered 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 I Natural Heritage Wetlands. Does the wetland unit contain individuals of Priority species listed by the SP3. WDFW for the state? Does the wetland unit have a local significance in addition to its functions? For SP4. example, the 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 Hydrogeomorphic Class of the wetland being rated. The hydrogeomorphic classification groups wetlands into those that function in similar ways. This simplifies the questions needed to answer how well the wetland functions. The Hydrogeomorphic Class of a wetland can be determinedusingthekeybelow.Seep.24formored..etailedinstructionsonclassifyingwetlands.. determinedusingthekeybelowSeep24formoredetailedinstructionsonclassifyingwetlands Wetland Rating Form - Western Washington 2 Herrera Environmental Consultants, Inc. Classification of Vegetated Wetlands in Western Washington If the hydrologic criteria listed in each question do not apply to the entire unit being rated, you probably have a unit with multiple HGM classes. In this case, indentify which hydrologic criteria in questions 1-7 apply and go to Question 8. 1. Are the water levels in the entire unit usually controlled by tides (i.e., except during floods)? NO - go to 2Tidal Fringe YES - the wetland class is If YES, is the salinity of the water during periods of annual low flow below 0.5 ppt (parts per thousand)? Freshwater Tidal FringeSaltwater Tidal Fringe (Estuarine) YES - NO - If your wetland can be classified as a Freshwater Tidal Fringe, use the forms for Riverine wetlands. If it is Saltwater Tidal Fringe, it is rated as an Estuarine wetland. Wetlands that were called estuarine in the first and second editions of the rating system are called Saltwater 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 being kept. Please note, however, that the characteristics that define Category I and II estuarine wetlands have changed (see p. xx). 2. The entire wetland unit is flat and precipitation is only source (>90%) of water to it. Groundwater and surface Flats NO - go to 3YES - the wetland class is Depressional If your wetland can be classified as a "Flats" wetland, use the form for wetlands. meet both 3.Does the entire wetland unit of the following criteria? The vegetated part of the wetland is on the shores of a body of open water (without any vegetation on the surface) where at least 20 acres (8 ha) are permanently inundated (ponded or flooded); At least 30% of the open water area is deeper than 6.6 feet (2 m)? NO - go to 4Lake-fringe (Lacustrine Fringe) YES - the wetland class is meet all 4.Does the entire wetland unit of the following criteria? lbdllope can be very gradual Thtldil(The wetland is on a slope ()). s 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. without being impounded. The water leaves the wetland Surface water does not pond in these type of wetlands except occasionally in very small and NOTE: shallow depressions or behind hummocks (depressions are usually <3 feet in diameter and less than 1 foot deep). NO - go to 5Slope YES - the wetland class is Wetland Rating Form - Western Washington 3 Herrera Environmental Consultants, Inc. 5. meet all Does the entire wetland unit 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 once every two years. NO - go to 6Riverine YES - the wetland class is 6.Is the entire wetland unit in a topographic depression in which water ponds, or is saturated to the surface, at some This means that any outlet, if present, is higher than the interior of the wetland. time of the year? NO - go to 7Depressional YES - the wetland class is 7.Is the entire wetland unit located in a very flat area with no obvious depression and no stream or river running through it and providing water? The wetland seems to be maintained by higher ground water in the area. The wetland may be ditched, but has no obvious natural outlet. NO - go to 8Depressional YES - the wetland class is 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 second class is less than 10% of the unit, classify the wetland using the class that represents more than 90% of the total area. HGM Classes Within a Delineated Wetland BoundaryClass to Use in Rating Slope + RiverineRiverine Slope + DepressionalDepressional Slope + Lake-fringeLake-fringe Depressional + Riverine along stream within boundaryDepressional Depressional + Lake-fringeDepressional SlttTidlFidthlffhttldatwater arnge an any oter cass oreswater wetanTtESTUARINEreat as SlTidlFidhlffhldTESTUARINE 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 2 HGM Depressional classes within a wetland boundary, classify the wetland as for the rating. Wetland Rating Form - Western Washington 4 Herrera Environmental Consultants, Inc. R Riverine and Freshwater Tidal Fringe Wetlands WATER QUALITY FUNCTIONS - Indicators that wetland functions to improve water quality. (see p. 52) to improve water quality? Does the wetland unit have the potential R 1. Points during a Area of surface depressions within the riverine wetland that can trap sediments R 1.1 flooding event : Depressions cover >3/4 area of wetland Points = 8 Depresssions cover >1/2 area of wetland Points = 4 2 If depressions >1/2 of area of unit, draw polygons on aerial photo or map Depressions present but cover <1/2 area of wetland Points = 2 No depressions are presentPoints = 0 Provide photo or drawing Figure __ R 1.2Characteristics of the vegetation in the unit : (areas with >90% cover at person height) Points = 8 Trees or shrubs >2/3 area of the unit Points = 6 Trees or shrubs >1/3 area of the unit 6 Points = 6 Ungrazed, herbaceous plants >2/3 area of the unit Points = 3 Ungrazed, herbaceous plants >1/3 area of the unit Trees, shrubs, and ungrazed herbaceous <1/3 area of unitPoints = 0 Aerial photo or map showing polygons of different vegetation types Figure __ 8 Add the points in the boxes above Total for R 1 (see p. 53) R 2.Does the wetland unit have the opportunity to improve water quality? Answer YES if you know or believe there are pollutants in ground water or surface water coming into the wetland that would otherwise reduce water quality in streams, lakes, or ground water downgradient Note which of the following conditions provide the sources of pollutants. A unit may from the wetland. have pollutants coming from several sources but any single source would qualify as an opportunity. Grazing in the wetland or within 150 feet Untreated stormwater discharges to wetland Tilled fields or orchards within 150 feet of wetland A stream or culvert discharges into wetland that drains developed areas, residential areas, farmedfieldsroadsorclear-cutlogging,,- farmedfieldsroadsorclearcutlogging Residential, urban areas, golf courses are within 150 feet of wetland Multiplier The river or stream linked to the wetland has a contributing basin where human activities have 2 raised levels of sediments, toxic compounds, or nutrients in the river water above standards for water quality Other: 21 YES - multiplier is NO - multiplier is TOTAL - Water Quality FunctionsMultiply the score from R 1. by R 2. 16 Add score to table on p. 1 Wetland Rating Form - Western Washington 5 Herrera Environmental Consultants, Inc. R Riverine and Freshwater Tidal Fringe Wetlands HYDROLOGIC FUNCTIONS - Indicators that wetland functions to reduce flooding/stream erosion. (see p. 54)Points R 3.Does the wetland unit have the potential to reduce flooding/erosion? Characteristics of the overbank storage the unit provides: R 3.1 Estimate the average width of the wetland unit perpendicular to the direction of the flow and the width of the stream or river channel (distance between banks). Calculate the ratio: (average width of unit)/(average width of stream between banks). If the ratio is more than 20Points = 9 1 If the ratio is between 10 - 20Points = 6 If the ratio is 5 - <10Points = 4 If the ratio is 1 - <5Points = 2 Points = 1 If the ratio is <1 Aerial photo or map showing average widths Figure __ Characteristics of vegetation that slow down water velocities during floods: R 3.2 Treat large woody debris as "forest or shrub". Choose points appropriate for the best description (polygons need to have >90% cover at person height NOT Cowardin classes). Points = 7 7 Forest or shrub for >1/3 area OR herbaceous plants >2/3 area Points = 4 Forest or shrub for >1/10 area OR herbaceous plants >1/3 area Vegetation does not meet above criteria Points = 0 Aerial photo or map shoing polygons of different vegetation types Figure __ Total for R 3Add the points in the boxes above 8 Does the wetland unit have the opportunity to reduce flooding/erosion? R 4. (see p.57) Answer YES if the unit is in a location in the watershed where the flood storage, or reduction in water velocity, helps protect downstream property and aquatic resources from flooding or excessive and/or erosive flows. Note which of the following indicators of opportunity apply: There are human structures and activities downstream (roads, buildings, bridges, farms) that can be damaged by flooding There are natural resources downstream (e.g. salmon redds) that can be damaged by Therearenaturalresourcesdownstream(e.g.salmonredds)thatcanbedamagedby flooding Multiplie r Other: Answer NO if the major source of water to the wetland is controlled by a reservoir or the wetland is 1 tidal fringe along the sides of a dike. 21 YES - multiplier is NO - multiplier is TOTAL - Hydrologic Functions Multiply the score from R 3. by R 4. 8 Add score to table on p. 1 Wetland Rating Form - Western Washington 6 Herrera Environmental Consultants, Inc. These questions apply to wetlands of all HGM classes HABITAT FUNCTIONS - Indicators that wetland functions to provide important habitat. H 1.Does the wetland unit have the potential to provide habitat for many species? Points (see p. 72) H 1.1Vegetation structure Check the types of vegetation classes present (as defined by Cowardin). Size threshold for class is 1/4 acre or more than 10% of the area if unit is smaller than 2.5 acres. Aquatic bed Emergent plants Scrub/shrub (areas where shrubs have >30% cover) Forested (areas where trees have >30% cover) If the unit has a forested class, check if: 1 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: Points = 4 4 structures or more Points = 2 3 structures Points = 1 2 structures Points = 0 1 structure Map of Cowardin vegetation classes Figure __ (see p. 73) H 1.2Hydroperiods Check the types of water regimes (hydroperiods) present within the wetland. The water regime has to cover more than 10% of the wetland if less than 2.5 acres in size or 1/4 acre to count (see text for descriptions of hydroperiods). Points = 3 Permanently flooded or inundated4 or more types present Points = 2 Seasonally flooded or inundated3 types present Occasionally flooded or inundated2 types presentPoints = 11 Saturated only1 type presentPoints = 0 Permanently flowing stream or river in, or adjacent to, the wetland Seasonally flowing stream in, or adjacent to, the wetlan d Lake-fringe wetland = 2 points Freshwater tidal wetland = 2 points Map of hydroperiods Figure __ (see p. 75) H 1.3Richness of Plant Species Count the number of plant species in the wetland that cover at least 10 sq. ft. (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. Points = 2 If you counted:>19 species 1 5-19 speciesPoints = 1 List species below if you want to: <5 speciesPoints = 0 Total for page3 Wetland Rating Form - Western Washington 7 Herrera Environmental Consultants, Inc. (see p. 76) H 1.4Interspersion of Habitats Points Decide from the diagrams below whether interspersion between Cowardin vegetation classes (described in H 1.1) or the classes and unvegetated areas (can include open water or mudflats) is high, medium, low, or none. 0 points1 point None = Low = 2 points1 Moderate = \[riparian braided channels\] 3 points High = NOTE: If you have four or more vegetation types or three vegetation types and open water, Use map of Cowardin classes the rating is always "high". (see p. 77) H 1.5Special Habitat Features 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 inches in diameter and 6 feet long). Standing snags (diameter at the bottom >4 inches) in the wetland. Undercut banks are present for at least 6.6 feet (2 m) and/or overhanging vegetation extends at least 3.3 feet (1 m) over a stream (or ditch) in or contiguous with the 0 wetland, for at least 33 feet (10 m). Stable steep banks of fine material that might be used by beaver/muskrat for denning cut shrubs or trees that (>30° slope) OR signs of recent beaver activity are present ( have not yet turned brown/gray ). At least 1/4 acre of thin-stemmed presistent vegetation or woody branches are present structures for egg-laying by in areas that are permanently or seasonally inundated ( amphibiansampans ). hibi) 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 4 Add the scores from H1.1, H1.2, H1.3, H1.4, H1.5 Comments: Wetland Rating Form - Western Washington 8 Herrera Environmental Consultants, Inc. H 2.Does the wetland unit have the opportunity to provide habitat for many species? Points (see p. 80) Buffers H 2.1 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." Points = 5 100 m (330 feet) of relatively undisturbed vegetated areas, rocky areas, or open water >95% of circumference. No structures are within relatively undisturbed also means no undisturbed part of buffer ( grazing, no landscaping, no daily human use ). 100 m (330 feet) of relatively undisturbed vegetated areas, rocky areas, Points = 4 or open water >50% of circumference. Points = 4 50 m (170 feet) of relatively undisturbed vegetated areas, rocky areas, or open water >95% circumference. 100 m (330 feet) of relatively undisturbed vegetated areas, rocky areas, Points = 3 or open water for >25% circumference. 2 Points = 3 50 m (170 feet) of relatively undisturbed vegetated areas, rocky areas, or open water for >50% circumference. If buffer does not meet any of the criteria above: No paved areas (except paved trails) or buildings within 25 m (80 feet) Points = 2 of wetland >95% circumference. Light to moderate grazing, or lawns are OK. No paved areas or buildings within 50 m of wetland for >50% Points = 2 circumference. Light to moderate grazing, or lawns are OK. Heavy grazing in buffer.Points = 1 Points = 0 Vegetated buffers are <2 m wide (6.6 feet) for more than 95% of the circumference (e.g., tilled fields, paving, basalt bedrock extend to edge of wetland). Buffer does not meet any of the criteria above.Points = 1 Aerial photo showing buffers Figure __ (see p. 81) H 2.2 Corridors and Connections part of a relatively undisturbed/unbroken vegetated corridor (riparian or upland) H 2.2.1Is the wetland ..stewetadpatoaeatveyudstubed/uboevegetatedcodo(paaoupad) at least 150 feet wide, has at least 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 Dams in riparian corridors, heavily used gravel roads, and paved roads are size? ( considered breaks in the corridor. ) 4 pointsgo to H 2.3go to H 2.2.2 YES = ()NO = H 2.2.2Is the wetland part of a relatively undisturbed/unbroken vegetated corridor (either riparian or upland) at least 50 feet wide, has at least 30% cover of shrubs or forest, and connects to 0 ORLake- estuaries, other wetlands, or undisturbed uplands that are at least 25 acres in size a fringe wetland, if it does not have an undisturbed corridor as in the question above? 2 pointsgo to H 2.3go to H 2.2.3 YES = ()NO = H 2.2.3Is the wetland: within 5 miles (8 km) of a brackish or salt water estuary OR within 3 miles of a large field or pasture > 40 acres in size OR within 1 mile of a lake greater than 20 acres in size? 1 point0 points YES = NO = Total for page 2 Wetland Rating Form - Western Washington 9 Herrera Environmental Consultants, Inc. (see p. 82) H 2.3Near or Adjacent to Other Priority Habitats Listed by WDFW Points Which of the following priority habitats are within 330 feet (100 m) of the wetland unit? NOTE: the connections do not have to be relatively undisturbed. These are DFW definitions. Check with your local DFW biologist if there are any questions Aspen stands: Pure or mixed stands of aspen >0.4 ha (1 acre). Biodiversity Areas and Corridors : Areas of habitat that are relatively important to full descriptions in WDFW PHS report p. various species of native fish and wildlife ( 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 than 100%; decay, decadence, number 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: Woodland stands of pure oak or oak/conifer associations where full descrptions in WDFW PHS canopy coverage of the oak component is 25% ( 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 Westside Prairies : Herbaceous, non-forested plant communities that can either take full descriptions in WDFW PHS report p. the form of a dry prairie or a wet prairie ( 161 ). 1 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 full descriptions Nearshore, Open Coastal Nearshore, and Puget Sound Nearshore. ( of habitats and the definition of relatively undisturbed are in WDFW report pp. 167- 169 and glossary in Appendix A). Caves : 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 occuring below 5,000 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 m (6.5 ft) in height. Priority logs are > 30 cm (12 in) in diameter at the largest end, and > 6 m (20 ft) long. 3+4points If wetland has:priority habitats = 11 point priority habitat = 23points0 points priority habitats = No habitats = 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 Wetland Rating Form - Western Washington 10 Herrera Environmental Consultants, Inc. one Choose the description of the landscape around the wetland that best fits. There are at least 3 other wetlands within 1/2 mile, and the connections Points = 5 between them are relatively undisturbed (light grazing between wetlands OK, as is lake shore with some boating, but connections should NOT be bisected by paved roads, fill, fields, or other development). Points = 5 The wetland is Lake-fringe on a lake with little disturbance and there 2 are 3 other Lake-fringe wetlands within 1/2 mile. Points = 3 There are at least 3 other wetlands within 1/2 mile, BUT the connections between them are disturbed. withPoints = 3 The wetland is Lake-fringe on a lake disturbance, and there are 3 other Lake-fringe wetlands within 1/2 mile. There is at least 1 wetland within 1/2 mile.Points = 2 Points = 0 There are no wetlands within 1/2 mile. H 2. TOTAL Score - opportunity for providing habitat 5 Add the scores from H2.1, H2.2, H2.3, H2.4 Total Score for Habitat Functions - add the points for H1 and H2, and record the result on p. 19 Wetland Rating Form - Western Washington 11 Herrera Environmental Consultants, Inc. CATEGORIZATION BASED ON SPECIAL CHARACTERISTICS Please determine if the wetland meets the attributes described below and choose the appropriate answers and Category. Wetland Type Check off any criteria that apply to the wetland. Check the appropriate Category when the appropriate criteria are met. Category (see p. 86) SC 1.0Estuarine Wetlands 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. Go to SC 1.1 YES - NO - not an estuarine wetland SC 1.1Is the wetland unit within a National Wildlife Refuge, National Park, National Estuary Reserve, Natural Area Preserve, State Park, or Educational, Environmental, or Scientific Reserve designated under WAC 332-30-151? Category IGo to SC 1.2 YES = NO = Is the wetland unit at least 1 acre in size and meeting at least two of the following three SC 1.2 conditions? The wetland is relatively undisturbed (has no diking, ditching, filling, cultivation, Spartina grazing, and has <10% cover of non-native plant species. If the non-native spp. are the only species that cover >10% of the wetland, then the wetland should be Spartina given a dual rating (I/II). The area of would be rated a Category II while the relatively undisturbed upper marsh with native species would be a Category I. Do not, Spartina however, exclude the area of in determining the size threshold of 1 acre. At least 3/4 of the landward edge of the wetland has a 100 foot buffer of shrub, forest, or ungrazed or unmowed grassland. gg The wetland has at least two of the following features: tidal channels, depressions with open water, or continguous freshwater wetlands. Category ICategory II YES = NO = Wetland Rating Form - Western Washington 12 Herrera Environmental Consultants, Inc. (see p. 87) SC 2.0Natural Heritage WetlandsCategory 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 2.1Is the wetland unit being rated in a Section/Township/Range that contains a Natural Heritage wetland? (This question is used to screen out most sites before you need to contact WNHP/DNR.) S/T/R information from Appendix D or accessed from WNHP/DNR web site (see p. 79)go to SC 3.2 YES - contact WNHP/DNR and NO SC 2.2Has DNR identified the wetland as a high quality undisturbed wetland or as a site with state Threatened or Endangered plant species? Category I YES = NO - not a Heritage wetland ( see p. 87) SC 3.0 Bogs Does the wetland unit (or any part of the unit) meet both the criteria for soils and vegetations If you answer Yes, you will Use the key below to identify if the wetland is a bog. in bogs? still need to rate the wetland based on its function. 1.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 the soil profile? (See Appendix B for a field key to identify organic oils.) go to Q. 3go to Q. 2 YES - NO - 2.Does the unit have organic soils, either peats or mucks, that are <16 inches deep over bedrock, or an impermeable hardpan such as clay or volcanic ash, or that are floating on a lake or pond? go to Q. 3 YES - NO - not a bog for purpose of rating 3.Does the unit have more than 70% cover of mosses at ground level, AND other plants, if present, consist of the "bog" species listed in Table 3 as a significant component of the vegetation (>30% of total shrub and herbaceous cover consists of species in Table 3)? go to Q. 4 YES - is a bog for purpose of ratingNO - 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 redcedar, western hemlock, lodgepole pine, quaking aspen, Englemann's spruce, or western white pine, WITH any of the species (or combination of species) on bog species plant >30% coverage of list in Table 3 as a significant component of the ground cover ( total shrub/herbaceous cover )? Category I YES = NO - not a bog for purpose of rating Wetland Rating Form - Western Washington 13 Herrera Environmental Consultants, Inc. (see p. 90) SC 4.0sCategory Forested Wetland Does the wetland unit have at least 1 acre of forest that meets one of these criteria for the If you answer Yes, you will still Department of Fish and Wildlife's forests as priority habitat? need to rate the wetland based on its functions. Old-growth forests : (west of Cascade Crest) Stands of at least 2 tree species, forming a multi-layered canopy with occasional small openings; with at least 8 trees/acre (20/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. 200-year-old trees in wetlands will often have a smaller dbh because their growth rates are often smaller. The DFW criterion is an "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 average diameters (dbh) exceeding 21 inches (53 cm); crown cover may be less than 100%; decay, decadence, numbers of snags, and quantity of large downed material is generally less than that found in old-growth. Category I NO - not a forested wetland w/ special characteristics YES = (see p. 91) SC 5.0Wetlands in Coastal Lagoons Does the wetland meet all of the following criteria of a wtland 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 needs to brackish (>.5 ppt) during most of the year in at leat a portion of the lagoon ( be measured near the bottom ). go to SC 5.1 YES = NO - not a wetland in a coastal lagoon SC 5.1Does the wetland meet all of the following 3 conditions? Thewetland is relativelyundisturbed(has nodiking,,ditching,, filling,,cultivation,, Thewetlandisrelativelyundisturbed(hasnodikingditchingfillingcultivation 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 foot buffer of shrub, forest, or ungrazed or unmowed grassland. The wetland is larger than 1/10 acre (4,350 square feet). Category ICategory II YES = NO = Wetland Rating Form - Western Washington 14 Herrera Environmental Consultants, Inc. (see p. 93) SC 6.0Interdunal WetlandsCategory Is the wetland unit west of the 1889 line (also called the Western Boundary of Upland Ownership or WBUO)? go to SC 6.1 YES - NO - not an interdunal wetland for rating If you answer Yes, you will still need to rate the wetland based on its functions. In practical terms, that means the following geographic areas: Long Beach Peninsula - lands west of SR 103 Grayland-Westport - lands west of SR 105 Ocean Shores-Copalis - lands west of SR 1115 and SR 109. SC 6.1Is wetland 1 acre or larger, or is it in a mosaic of wetlands that is 1 acre or larger? go to SC 6.2 Category IINO - YES = SC 6.2Is the unit between 0.1 and 1 acre, or is it in a mosaic of wetlands that is between 0.1 and 1 acre? Category III YES = 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. Wetland Rating Form - Western Washington 15 Herrera Environmental Consultants, Inc. APPENDIX E Representative Site Photographs Critical Areas Report and Mitigation Plan—Talbot Road – Perrinville Creek Drainage Improvement Talbot Road – Perrinville Creek Drainage Improvement Project Representative Site Photographs Photo Number Photo Description 1 Looking downstream (northwest) at lower Perrinville Creek within the project area – illustrating riparian corridor and stream channel conditions. 2 Looking downstream (northwest) at lower Perrinville Creek within the project area – illustrating stream channel and substrate conditions in greater detail. 3 Looking upstream (northeast) at existing outfall for unnamed tributary to Perrinville Creek within the project area. 4 Riparian buffer conditions within the project area (looking south). 5 Looking northeast at Wetland A. lt 08-04119-000 apx-e talbot photo log.doc January 19, 2010 E-1 Herrera Environmental Consultants Road – Perrinville Creek Drainage Improvement Herrera Environmental Consultants Critical Areas Report and Mitigation Plan—Talbot 24 E-3 lt 08-04119-000 apx-e talbot photo log.doc January 19, 2010 3 1 Road – Perrinville Creek Drainage Improvement Herrera Environmental Consultants Critical Areas Report and Mitigation Plan—Talbot E-4 lt 08-04119-000 apx-e talbot photo log.doc January 19, 2010 5