TRAIL MITIGATION PLAN

Transcription

1 FOR BAY HORIZON PARK MAY 2009 prepared for Whatcom County Parks 3373 Mt Baker Highway Bellingham, WA prepared by Northwest Ecological Services, LLC 1229 Cornwall Ave, Suite 313 Bellingham, WA

2 EXECUTIVE SUMMARY Northwest Ecological Services (NES), LLC prepared this Mitigation Report in accordance with environmental regulations protecting wetlands and streams, as administered by Whatcom County, the Washington State Department of Ecology (DOE), the U.S. Army Corps of Engineers (Corps), and the Washington Department of Fish and Wildlife (WDFW). The project site is located on a portion of a 55-acre site (parcel ) located just south of Alderson Road in Whatcom County, Washington (Section 31, Township 40N, Range 1E, W.M.) The site is currently used as a Whatcom County park. A wetland delineation of the site was performed by NES in February of NES biologists identified eleven wetlands (A to K), numerous seasonally flowing drainages, and one un-named stream on site. Wetlands A, F, H, J, and an un-flagged wetland are depressional, DOE Category III wetlands. Wetlands B, C, D, and E are slope, DOE Category III wetlands. Wetland G, I, and K are depressional, DOE Category IV wetlands. The stream contains documented fish habitat. The project area is limited to a small area in the southwest corner of the site. The proposed project includes construction of a gravel pedestrian/ bicycle trail that will provide access between the County Park and adjacent residential development to the west. A portion of the trail was constructed in This mitigation report proposes leaving the installed portion of the trail in its current location. Overall, the project will result in 4,041 s.f. of wetland fill in Wetland F, and 6,790 s.f. of buffer infringement. This includes impacts for areas of the trial already installed and the remaining proposed alignment. The most significant impacts due to the development are anticipated reductions in water quality treatment, run-off filtration, and hydrologic function. Impacts to other wetland functions are anticipated to be limited, due to the existing condition of the site. Compensatory mitigation for site impacts includes 32,400 s.f. of wetland enhancement, and 6,800 s.f. of buffer enhancement. The mitigation area shall be monitored for a period of ten years by a qualified biologist to determine project success. Maintenance of the mitigation project will be provided for a minimum of ten years after installation. All mitigation areas will be protected under a restrictive conservation easement that permanently protects the site as natural, open space. Signage will identify limits of the conservation area on the ground. BAY HORIZON PARK I

3 TABLE OF CONTENTS 1.0 BACKGROUND BACKGROUND ECOLOGICAL ASSESSMENT EXISTING CONDITIONS PROJECT OVERAVIEW ENVIRONMENTAL FEATURES SUMMARY REGULATORY SUMMARY Whatcom County State and Federal IMPACT ASSESSMENT PROPOSED SITE PLAN PROPOSED IMPACTS IMPACT ANALYSIS Water Quality Improvement/ Runoff Filtration Hydrology Functions Thermal Protection Wildlife Habitat Impact Summary MITIGATION MITIGATION SEQUENCING MITIGATION STRATEGY WETLAND AND BUFFER ENHANCEMENT GOAL, OBJECTIVES AND PERFORMANCE STANDARDS Wetland Enhancement Buffer Enhancement Project Protection POST IMPACT FUNCTIONS METHODS Site Preparation Soil Amendments Plant Installation MONITORING AND MAINTENANCE CONTINGENCY PLAN 17 APPENDICES A: LITERATURE REVIEWED B: FIGURES C: MONITORING CONTRACT BAY HORIZON PARK II

4 1.0 BACKGROUND 1.1 Background Northwest Ecological Services, LLC (NES) was retained to prepare a mitigation plan for a proposed Whatcom County Parks development project. The project site is located on a portion of a 55-acre site (parcel ) located just south of Alderson Road in Whatcom County, Washington (Section 31, Township 40N, Range 1E, W.M.) (Figure 1, Appendix B). A Wetland Delineation of the 55-acre parcel was conducted by NES in February of In this delineation NES staff identified eleven wetlands, numerous seasonally flowing drainages, and one unnamed stream onsite. A sketch map showing the approximate location of these features is included as Figure 2 (Appendix B). This mitigation plan describes existing conditions, analyzes impacts, and presents mitigating actions that will maintain, protect and enhance existing wetland, stream, and buffer functions in accordance with applicable environmental regulations. This report is intended for inclusion with future development permit submissions Whatcom County, the U.S. Army Corps of Engineers (Corps), Washington State Department of Ecology (DOE), and Washington Department of Fish and Wildlife (WDFW) as may be required. Project Applicant: Lynne Givler Whatcom County Parks Department 3373 Mount Baker Highway Bellingham, WA Report Prepared By: Michele Bodtke and Molly Porter Northwest Ecological Services, LLC 1229 Cornwall Ave, Ste 313 Bellingham, WA Telephone: ECOLOGICAL ASSESSMENT 2.1 Existing Conditions The project site is located south of Alderson Road near Birch Bay, Washington. The site was formerly used as an air force base and has an extensive built environment in the center of the property, including several paved roads and nearly two dozen buildings. The site is currently used as a County park and hostel facility. The Lions Foundation manages the majority of buildings, and conducts a summer camp for the disabled, and the Birch Bay Lions Club BAY HORIZON PARK 1

5 manages one building as an overnight hostel. Numerous man-made ditches run throughout the property, and an un-named stream flows north and south along the eastern property line continuing west through the northwest corner, and off-site toward Terrell Creek (Figure 2, Appendix B). The area outside of the built environment is vegetated in a forested/scrub shrub structure, with some areas of emergent meadow dominated by non-native pasture grasses. The northern tip of the parcel is a fallow baseball field. The entire un-built portion site is exceptionally hummocky and shows signs of disturbance and old fill in several areas. 2.2 Project Overview The proposed project includes construction of a gravel pedestrian/ bicycle trail in the southwest portion of the site. Larry Steele and Associates surveyed the wetland delineation in this area (Figure 3, Appendix B). Only the area included in Figure 3 is referred to as the project site. No work is currently proposed in other areas of the parcel. Detailed information on project design is included under Proposed Site Plan, below. 2.3 Environmental Features Summary NES biologists identified eleven wetlands, numerous seasonally flowing drainages, and one unnamed stream on-site. A sketch map showing the approximate location and extent of wetlands, drainages, and the stream is included as Figure 2 (Appendix B). A surveyed map of the project area is included as Figure 3 (Appendix B). A summary of the wetland categories, hydrogeomorphic classifications, and Cowardin classifications, is included in Table 1. For additional information refer to the Wetland Delineation Report (NES, 2008). Table 1. Wetland Classification and Categorization Summary Wetland Unit Hydrogeomorphic Class Cowardin Classification DOE Wetland Category A Depressional PFO, PEM, PSS III B Slope PEM, PSS III C Slope PFO, PEM, PSS III D Slope PEM III E Slope PEM III F Depressional PFO, PEM, PSS III G Depressional PSS IV H-1 Depressional PFO, PEM, PSS III H-2 Depressional PFO, PEM, PSS III I Depressional PFO, PEM IV J Depressional PFO, PEM, PSS III K Depressional PEM IV Unflagged Depressional PEM III PEM=Palustrine emergent, PSS=Palustrine scrub-shrub, PFO=Palustrine forested BAY HORIZON PARK 2

6 2.4 Regulatory Summary Whatcom County The Whatcom County Critical Areas Ordinance (CAO) states that no activity may be conducted within a regulated wetland or buffer without Critical Areas review and approval. Activities impacting regulated wetlands generally must provide mitigation sufficient to maintain or enhance the wetland functions. Whatcom County also requires a buffer around regulated wetlands to protect functions. The buffer must remain naturally vegetated except where it can be enhanced to improve the functions (Whatcom County, 2005c). Wetland buffers are based on overall DOE Categorization, DOE Wildlife Habitat Scores (low), and intensity of land use (high). A summary of Whatcom County regulated buffer widths around all regulated wetlands in the vicinity of the project site are shown in Table 2 below. Table 2.. Summary of Whatcom County Regulated Buffers DOE DOE Habitat Wetland Category Score Buffer Width (feet) A III B III C III D III 9 80 E III 9 80 F III G IV 8 50 H (Units 1 & 2) III I IV 9 50 J III K IV 7 50 Un-flagged (2) III 9 80 Whatcom County also regulates streams and potentially other drainages. A fish bearing stream requires a 100 foot buffer, while a non-fish bearing stream requires a 50 foot buffer. The on-site stream is mapped as fish bearing and therefore requires a 100 foot buffer. Most of the ditches on-site are adjacent to, or associated with, regulated wetlands and would therefore be regulated. These ditches would be regulated as non-fish bearing streams and therefore require a 50 foot buffer. Internal ditches that are located in upland areas may be regulated. Final determination of regulatory status rests with Whatcom County, DOE, WDFW, and Corps State and Federal Activities altering wetlands, streams, and drainage ditches may require permit authorization from the Corps and DOE under Sections 404 and 401 of the federal Clean Water Act. BAY HORIZON PARK 3

7 Wetlands A, B, C, D, E, F, G, H, I and J are each abutting, or connected through surface flow, to drainages that flows to the un-named stream on-site, or to the stream itself. Wetland K drains into a storm drain. The un-flagged wetlands are the only wetlands on-site that appear to have no outlet and may be considered isolated. Based on our assessment, it appears that the Corps would have jurisdiction over all site wetlands, except potentially Wetland K; and DOE appears to have jurisdiction overall all aforementioned features. Only the aforementioned agencies have the authority to make jurisdictional determinations. The WDFW requires issuance of a Hydraulic Project Approval (HPA) prior to any activities that may directly or indirectly affect streams or associated wetlands. Mitigation may be required for impacts. Prior to any work the land owner must contact WDFW, to determine if an HPA is required for site development. 3.0 IMPACT ASSESSMENT 3.1 Proposed Site Plan The proposed site plan includes construction of a gravel pedestrian/ bicycle trail that will provide access between the County Park and adjacent residential development to the west. The proposed trail alignment is detailed in Figure 4 (Appendix B). The trail will be approximately 1,400 linear feet long by approximately eight feet wide. Two pedestrian bridges will be installed where the trail crosses a ditch and accesses the adjacent development (Figure 4, Appendix B). A portion of the trail has been already constructed (the area south of the location detailed in Figure 4, Appendix B). This work was done in The County Parks Department was under the assumption that no wetlands were located in this area of the site. Upon realization that wetlands were present, and may be affected by the proposed activity, construction stopped and NES was contracted to perform a wetland delineation of the site. This mitigation report proposes leaving the installed portion of the trail in its current location. Leaving the portion of the trail already constructed in its current location is intended to minimize additional land disturbance and vegetation clearing on-site. It appears that the trail could not have been constructed any farther from site wetlands due to existing locations of culverts and drainages. The entire project area is within a wetland or wetland/ stream buffer. Therefore, overall impact to site critical areas is un-avoidable. The fill that has already occurred in Wetland F likely could not have been avoided with trail alignment in this location, as fill would either have to occur in the wetland or the adjacent, associated drainage ditch. 3.2 Proposed Impacts The proposed project would result in 4,041 square feet (s.f.) of fill in Wetland F, and 6,790 s.f. of buffer impact. Regulated features in the immediate vicinity of the proposed site plan include Wetlands F, G, H, and associated drainages. No impacts are proposed to Wetlands G and H, or drainages. BAY HORIZON PARK 4

8 3.3 Impact Analysis The following sections provide an analysis of proposed impacts to the functional components of the site wetlands and associated buffers. For a detailed description of wetland and buffer functions refer to the Wetland Delineation Report (NES, 2008) Water Quality Improvement/ Run-off Filtration Wetland F and its associated buffer provides moderate to high water quality function. Wetland F is a depressional wetland with an intermittently flowing outlet that has persistent, ungrazed vegetation in greater than 95% of the area. The wetland also exhibits seasonal ponding in greater than a quarter of the area. Wetland G and its associated buffer provides low water quality function. Wetland G is a depressional wetland with an unconstricted surface outlet and very little seasonal ponding. However, it does have persistent, ungrazed vegetation in greater than half of its area. For the purpose of a functional assessment, Wetland H is divided into two parts, H-1 (the northern portion) and H-2 (the southern portion) (Figure 3, Appendix B). Wetland H-1 shares all of the same characteristics of Wetlands F. Wetland H-2 provides lower water quality function due to an unconstricted outlet which does not allow water to be detained for long, and a limited area of seasonal ponding. Wetlands F, G, and H all have the opportunity to provide water quality function as they are adjacent to developed areas that could potentially contribute pollutants. Determination- A decrease in water quality improvement and run-off filtration is anticipated to occur under the proposed project due to increase of impervious surfaces, wetland fill, and buffer infringement. The trail will be constructed of compact gravel, which is functionally impervious, and will introduce approximately 11,200 s.f. of additional impervious surface on-site Hydrology Wetlands F and Wetland H-1 and their associated buffers each provide low to moderate hydrologic function. They have intermittently flowing outlets, except Wetland H-1 which has a constricted outlet. Marks of ponding are less than six inches above the bottom of the outlets, indicating very little depth of storage during wet periods. They contribute moderate storage in the watershed. Wetlands G and Wetland H-2 and their associated buffers provide low hydrologic function. Wetland G has an unconstricted surface outlet, marks of ponding at less than six inches and the wetland is small relative to the basin size. Wetland H-2 has slightly higher hydrologic function mainly because it provides more water storage capacity. BAY HORIZON PARK 5

9 Wetlands F, G and H all have the opportunity to reduce flooding and erosion as they drain to a stream that has flooding problems, documented fish habitat, and adjacent residential development. Determination- A decrease in hydrologic flood/stormwater and baseflow/groundwater support is anticipated with the proposed fill due to overall loss of wetland and subsequent water storage capacity; and buffer infringement Thermal Protection Vegetation can provide important functions in moderating temperatures within a stream, lake, or wetland, and in providing food sources and cover to aquatic organisms. Vegetation in the wetland and buffers provides thermal protection function ranging from a low to a high level in localized areas of the site. The project area ranges from being dominated by grasses or emergent species to forested areas. Overall, the trail alignment is located in a forested location, but vegetation is dominated by small to moderate size deciduous trees or shrubs which limits this functions. Determination- A limited reduction in thermal protection function is anticipated under the proposed site plan in areas where vegetation removal, particularly tree removal, is required Wildlife Habitat Wetlands F and H and their associated buffers provide moderate wildlife habitat functions overall. They have forested, scrub/shrub and emergent vegetation present yielding moderate to high structural and species diversity. In addition, Wetlands F and H-1 are adjacent to riparian habitat (the un-named stream). The wetlands have fairly low functioning buffers, but have no paved areas or buildings within 170 feet for greater than 50 percent of their circumference. Wetland H-2 does not have riparian habitat, but has a higher functioning buffer that includes at least 170 feet of relatively undisturbed vegetated area over greater than 50 percent circumference. The wetlands are also within five miles of a salt water estuary and have at least three other wetlands within half of a mile but the connections between them are disturbed. Wetland G and associated buffers provide fairly low habitat functions overall. The wetland is relatively small, and has low structural and species diversity. The wetland has only an emergent vegetation class present. A limited number of trees (red alder [Alnus rubra]) are present but they do not cover more than 10-percent of the total area. The wetland contains no documented priority species or habitats, and has low functioning buffers. Determination A limited reduction in wildlife function is anticipated under the proposed project due to wetland fill, buffer infringement, vegetation removal and increased human presence in this area of the site. Impacts to wildlife habitat are anticipated to be limited, as wildlife use of the site is currently limited due to existing on-site and adjacent development. BAY HORIZON PARK 6

10 3.3.5 Impact Summary The most significant long-term impacts identified with the proposed wetland fill and buffer reductions for this project are associated with potential decreases in water quality treatment, runoff-filtration, and hydrology functions. A lesser reduction is anticipated to thermal protection and wildlife habitat functions, but these are anticipated to be limited because overall these functions are currently limited within the project area. 4.0 MITIGATION 4.1 Mitigation Sequencing The applicant has designed the project in attempt to minimize impacts to wetlands and associated buffers according to mitigation sequencing: A. Avoid. The project will avoid directly impacting Wetlands G and H. Under the current site plan, impacts to Wetland F and buffers are un-avoidable in order to connect the trail to the access easement to the west. The purpose of the trail is to provide park access to the adjacent residential community. B. Minimize. The entire project area is located within a wetland or wetland buffer. Therefore, impacts to site critical areas are unavoidable if installation of the project is to proceed. The fill that has already occurred in Wetland F likely could not have been avoided with trail alignment in this location, as fill would either have to occur in the wetland or the adjacent, associated drainage ditch. Due to the location of the existing public trail and utility easement, and extensive wetlands in this area of the site, there is no alignment that would eliminate additional wetland fill in the northwestern portion of the project area. Impacts to ditches along the western edge of the wetlands will be minimized by installing pedestrian bridges. C. Rectify. Temporary water quality impacts could potentially result if best management practices (BMP s) are not adhered to during construction activities. Therefore, all contractors working on-site will adhere to BMP s outlined in this mitigation plan, and the current Department of Ecology (DOE) stormwater manual. D. Reduce or Eliminate the Hazard by Preservation and Maintenance Operations. The remaining wetlands and buffers within the project area will be protected by signage, and will be placed under a permanent conservation easement or covenant to prevent future development of the area. E. Compensate. Mitigation for impacts includes wetland and buffer enhancement, which is intended to maintain functions at existing conditions as described below: In order to maintain water quality function on-site the applicant has proposed to enhance the retained wetlands and buffers through the addition of woody plant material in areas where it is currently limited on-site. Vegetation serves a number BAY HORIZON PARK 7

11 of important functions to improve water quality and run-off rates. Vegetation acts through a variety of manners, including interception, evapotransporation, conveyance attenuation, temperature moderation, and photoremediation to reduce runoff rates and improve water quality. These processes serve to retain, detain, cool water, and reduce pollutants in runoff. The greater the vegetation structure the more potential the buffer has to detain and cleanse runoff. Wetland enhancement is intended to replace lost water storage capacity and maintain hydrology functions on-site. Planting native shrubs and trees within the wetlands is intended to increase the degree of rainwater interception and year round water uptake within the biomass of woody plants. Woody plants will also add increased friction to decrease the runoff velocity of surface waters, and increase the stormwater functions within the project area. In addition, the application of mulch will further increase infiltration capacity, slow stormwater run-off, and promote pollutant removal through biological soil activity. Thermal protection functions will be increased by planting trees and shrubs in the retained wetlands, buffers, and along the drainage northeast of Wetland F. Multiple layers of vegetation will help ensure good shade cover. Enhancing the retained wetlands and buffers with a more diverse native plant community will increase the habitat suitability to a wider variety of wildlife species. Trees shall be planted along the southern boundary to provide screening between the project site and residential development to the south. Additionally, shrubs shall be planted densely in localized areas along the trail alignment, where woody vegetation is currently limited, to provide screening and detour human and pet disturbance in the wetland. 4.2 Mitigation Strategy Compensatory mitigation for impacting the site wetlands and buffers is proposed through a minimum of 32,400 s.f. of wetland enhancement and 6,800 s.f. of buffer enhancement. This provides a 8:1 enhancement to impact ratio for proposed wetland fill, and a 1:1 enhancement to impact ratio for buffer infringement. Figure 5, Appendix B, presents the conceptual area for mitigation activities. Table 3 summarizes proposed impacts and mitigating actions. Table 3. 3 Summary of Proposed Impacts and Mitigating Actions. Wetland Fill (s.f.) Buffer Infringement (s.f.) Wetland Enhancement (s.f.) Buffer Enhancement (s.f.) 4,041 6,790 32,400 6,800 BAY HORIZON PARK 8

12 4.3 Wetland and Buffer Enhancement Mitigation shall include enhancement of the wetland and buffers, as designated in Figure 5 of this report, and shall include installation of native trees and shrubs and removal of invasive species. Five planting areas have been designated for wetland enhancement. A general description of each wetland enhancement area is detailed below: Area A. Enhancement in Area A includes tree installation along the western property line to provide screening between the mitigation site and the residential development to the west, and along the drainage ditch north of Wetland F, to provide shade to surface waters. Trees shall be installed approximately 40 feet from the property line to accommodate existing shrubs. Area B. Enhancement in Area B includes installation of shrubs along the trail to provide screening between the trail and the mitigation site, and discourage human and pet intrusion in the adjacent wetland. Area C. Enhancement in Area C includes installation of native trees and shrub species in an area currently dominated by pasture grasses and weedy herbaceous species. Area D. Enhancement in Area D includes installation of western red cedars (Thuja plicata) under a small stand of young red alder trees. Five cedars shall be planted in each of the three alder stands. Area E. Enhancement in Area E includes installation of additional trees and shrubs in an area dominated by young red alder in order to increase the native species diversity and community structure in this location. Native plants have been found to provide superior habitat to native wildlife species. Native species provide more suitable structure, cover and forage than cultivated plant species typically introduced into landscapes. Plants native to this region are adapted to our summer drought and typically develop deep root systems that increase infiltration into the soils and reduce the need for irrigation once the plants are established. Infiltration of surface water has been shown to be the most effective at improving water quality. Furthermore, native plants of this region are resistant to native pests and disease and typically require little or no fertilizer, pesticide or herbicide application. All plant selections must be native to Western Washington, and substitutions must be approved by an approved biologist familiar with restoration projects. 4.4 Goals, Objectives and Performance Standards Wetland Enhancement The target vegetative assemblage for the on-site wetland enhancement area is forested/scrubshrub. Trees and/or shrubs native to lowland habitats of Whatcom County will be installed throughout wetland enhancement areas. BAY HORIZON PARK 9

13 Goal 1. The goal of the on-site wetland enhancement is to increase native species diversity within a minimum of 32,400 square feet of wetland resulting in enhanced functions. Objective 1a. Increase water quality, hydrologic, thermal protection, and habitat functions within the on-site wetland by enhancing 32,400 square feet with native tree and shrub species. Performance Standard 1.a.1 Table 4 represents the desired vegetation standards for all proposed on-site wetland enhancement areas. Table 4.. Performance standards for vegetation in the on-site wetland enhancement areas Rated Item Year 1 Year 2 Year 4 Year 6 Year 8 Year 10 Long Term Survival (%) 100 >80 >80 >80 >80 >80 Natural Mortality Tree/shrub (mean % cover) < 5 > 5 > 10 > 30 > 50 > % Performance Standard 1.a.2. The wetland enhancement area shall contain a minimum of one species of trees and three species of shrubs by the end of the 10- year monitoring period. Performance Standard 1.a.3: Invasive plant species shall comprise no more than five percent of the woody plant community (including vines) and no more than 15% of the herbaceous community (excluding reed canarygrass) in the enhancement area. Invasive plants include those listed in Table 5 and any other invasive species that may threaten the success of the mitigation area. BAY HORIZON PARK 10

14 Table 5. Invasive Plants That Must Be Removed Common Name Latin Name Blackberry, Cutleaf Blackberry, Himalayan Everlasting Pea Geranium, Robert's Hawkweeds (Orange, Smooth, Yellow, European Hogweed, Giant Knapweed, Meadow Knapweed, Spotted Knotweeds (Japanese, Giant, Bohemian, Himalayan) Loosestrife, Garden Loosestrife, Purple Parrotfeather Scotch Broom Tansy Ragwort Teasel Thistle, Canadian Toadflax, Dalmatian Travelers Joy Willowherb, Hairy Yellow Floating Heart Rubus laciniata Rubus procerus Lathyrus latifolius Geranium robertianum Hieracium aurantiacum, H. laevigatum, H. caespitosum, H. sabaudum Heracleum mantegazzianum Centaurea jacea x nigra Centaurea stoebe Polygonum cuspidatum, P. sachalinense, P. x bohemicum, P. polystachyum Lysmachia vulgaris Lythrum salicari, L. virgatum Myriophyllum aquaticum Cytisus scoparius Senecio jacobaea Dipsacus fullorum Cirsium arvense Linaria dalmatica sp. dalmatica Clematis vitalba Epilobium hirsutum Nymphoides peltata Buffer Enhancement The target vegetative assemblage for the buffer enhancement area is forested/scrub-shrub. Trees and shrubs native to lowland habitats of Whatcom County will be installed throughout the buffer enhancement areas. Goal 1. The goal of the buffer enhancement is to increase native species diversity in a minimum of 6,800 square feet of upland buffer to restore historic functions associated with the forested systems on this site. Objective 1a. Increase water quality, hydrologic, thermal protection, and habitat functions within the on-site buffer by enhancing 6,800 square feet with native tree and shrub species. Performance Standard 1.a.1 Table 6 represents the desired vegetation standards for the proposed on-site buffer enhancement areas. BAY HORIZON PARK 11

15 Table 6.. Performance standards for vegetation in the on-site buffer enhancement Rated Item Year 1 Year 2 Year 4 Year 6 Year 8 Year 10 Long Term Survival (%) 100 >80 >80 >80 >80 >80 Natural Mortality Tree/shrub (mean % cover) < 5 > 5 > 10 > 30 > 50 > % Strata Project Protection Performance Standard 1.a.2. The buffer enhancement area shall contain a minimum of two species of trees and two species of shrubs by the end of the 10- year monitoring period. Performance Standard 1.a.3: Invasive plant species shall comprise no more than five percent of the woody plant community (including vines) and no more than 15% of the herbaceous community (excluding reed canarygrass) in buffer the enhancement area. Invasive plants include those listed in Table 5 and any other invasive species that may threaten the success of the mitigation area. To ensure protection and conservation of the mitigation area the applicant has proposed the following: The entire mitigation area shall be placed into a permanent conservation easement with Whatcom County. Native Growth Protection Area (NGPA) signs shall be installed along the trail as shown in Figure 5, Appendix B. 4.5 Post Impact Functions Enhancements within the site will take up to three years before significant functional improvements may be realized. After this time, the functional performance is expected to be equal to or greater than the pre-construction conditions. During the establishment period there may be a slight net loss of buffer function in the vicinity of the impacted wetland and buffer. 4.6 Methods Site Preparation Work within the proposed mitigation areas will abide by the following construction schedules (Table 7). All phases of construction will follow Best Management Practices (BMP s) detailed in the current DOE Stormwater Manual to prevent erosion and sediment entering surface waters. All exposed soils shall be mulched immediately with a minimum of four inches of clean wood chips or straw (not hay) consistent with standard BMP s. BAY HORIZON PARK 12

16 Table 7. Proposed Mitigation Construction Schedule. Task Jan Feb Mar Apr May June July Aug Sept Oct Nov Dec Site Preparation Planting The following are primary tasks associated with successful mitigation site preparation and project installation: Silt Fence. A properly installed silt fence shall be installed between the construction site and retained wetland and buffers prior to any construction or site preparation activities on-site. The fence will provide water quality protection and define the active work area. Silt fence must be removed once construction is complete and erosion is stabilized. Removal of aggressive exotics from within the mitigation area, particularly any Himalayan blackberry. Plants shall be removed via mechanical methods; this includes hand pulling, cutting, and root removal. NO chemical controls are recommended to be used on this site, at this time. Removal or control of the existing grass species within the planting area to reduce root competition with installed plants. One of the following methods may be used: 1) Placing a cardboard layer under 4 inches of mulch to suppress grass. This is best done after plants are installed. Cardboard must be heavy gauge cardboard, free of any plastic or wax. Cardboard must be tacked down into the soil to prevent movement. 2) Removal of grass species by digging out roots and disposal off-site. 3) Mowing around installed plants a minimum of three times per growing season. Install plants and perform soil amendments (mulch) as described below. Install NGPA signs as required by this mitigation plan Soil Amendments Soil amendments shall be provided through the addition of woodchip mulch. Mulch shall be applied in a three foot radius around each installed plant to a minimum depth of four inches. No mulch shall be placed within one inch of the plant stems but shall cover the rootballs to the maximum extent possible. Mulch shall consist of woodchips with greens, woodchips with no greens, or coarse shredded bark. Woodchips shall not consist of beauty bark. Woodchip size shall average between 1/4 and 1/2 inches thick and 1 to 3 inches long (thin cut pulp chips are ideal). Mulch shall be refreshed annually for a minimum of three years, or upon biologist recommendation. BAY HORIZON PARK 13

17 4.6.3 Plant Installation Planting shall take place during the dormant season (fall or winter and no later than April 1 st ). The following standards shall be adhered to during plant installation: Installation must be done according to the approved planting plan; Plant material shall be obtained from native plant nurseries growing stock from the Puget Sound lowlands. When possible, obtain plants from a local nursery. Provide NES staff written documentation from the plant supplier verifying plant origination PRIOR to plant installation. All plants must be inspected by a qualified biologist prior to installation; and After installation, a qualified biologist shall inspect the site to verify all plants were installed according to design and are in good health. Container plants are preferred for this project, however if bareroot stock is used the plants numbers should be increased by 20% to compensate for increased mortality. The following standard specifications for spacing and size of plant material will be used: Generally, trees and shrubs shall be placed on four to eight foot centers (on average) with a minimum of a one gallon size or two year old bareroot material. Installation contractor shall coordinate with NES staff prior to installation; Staked, 18 inch plant protectors (i.e. Protex Pro/Gro Solid Tube Tree Protectors, from Forestry Suppliers Inc.) shall be installed around all trees and shrubs to protect them from rodent damage. Tubes shall be removed around plants once they begin to out grow them (typically in the third year), or upon biologist recommendation. All installed plants will be marked with flagging for identification. Actual size of plant material may vary depending on availability. A qualified biologist must approve any substitutions. Tables 8 to 13 detail the proposed planting specifications for the mitigation areas. Table 8.. Planting Specifications for the Wetland Enhancement Area A (approx.( 8,750 s.f.) Grade Scientific Name Common Name Condition (min. size) Spacing # Plants Trees Populus balsamifera Black cottonwood B/C 2 yrs. 18 min/ 8 50 Picea sitchensis Sitka spruce B/C 1 gallon 8 50 Salix lucida Pacific willow B/C 8 40 B= bareroot, C= container Total 140 BAY HORIZON PARK 14

18 Table 9.. Planting Specifications for the Wetland Enhancement Area B (approx.( 8,750 s.f.) Grade Scientific Name Common Name Condition (min. size) Spacing # Plants Shrubs Pyrus fusca Western crabapple B/C 8 50 Rosa nutkana Nootka rose B/C Spiraea douglasii Douglas spiraea B/C 2 yrs. 18 min/ Rubus spectabilis Salmonberry B/C 1 gallon B= bareroot, C= container Total 400 Table 10.. Planting Specifications for the Wetland Enhancement Area C (approx. 8,000 s.f.) Grade Scientific Name Common Name Condition (min. size) Spacing # Plants Trees Salix lucida Pacific willow B/C 8 30 Picea sitchensis Sitka spruce B/C 8 20 Shrubs Salix hookeriana Hooker s willow B/C 2 yrs. 18 min/ 1 gallon 8 50 Salix sitchensis Sitka willow B/C 8 50 Physocarpus capitatus Pacific ninebark B/C 8 50 Lonicera involucrata Black twinberry B/C 4 50 Rosa nutkana Nootka rose B/C 4 50 Spiraea douglasii Douglas spiraea B/C 4 50 B= bareroot, C= container Total 350 Table 11.. Planting Specifications for the Wetland Enhancement Area D (approx.( 1000 s.f.) Scientific Name Common Name Condition Trees Thuja plicata Western red cedar B/C Grade (min. size) Spacing # Plants 2 yrs. 18 min/ 1 gallon 8 15 B= bareroot, C= container Total 15 Table 12.. Planting Specifications for the Wetland Enhancement t Area E (approx.( 5,900 s.f.) Grade Scientific Name Common Name Condition (min. size) Spacing # Plants Trees Picea sitchensis Sitka spruce B/C 8 50 Thuja plicata Western red cedar B/C 8 50 Shrubs Rubus spectabilis Salmonberry B/C 2 yrs. 18 min/ 1 gallon 4 75 Lonicera involucrata Black twinberry B/C 4 50 Rosa nutkana Nootka rose B/C 4 75 Spiraea douglasii Douglas spiraea B/C 4 50 B= bareroot, C= container Total 350 BAY HORIZON PARK 15

19 Table 13.. Planting Specifications for the Buffer Enhancement Area (6,800( 6,800s.f.) Grade Scientific Name Common Name Condition (min. size) Spacing # Plants Trees Pinus contorta Shore pine B/C 8 30 Populus balsamifera Black cottonwood B/C 8 15 Rhamnus purshiana Cascara B/C 2 yrs. 18 min/ 8 25 Shrubs 1 gallon Amelanchier alnifolia Serviceberry B/C 8 50 Cornus cornuta Beaked hazelnut B/C 8 50 Rubus parviflorus Thimbleberry B/C 4 50 Rosa nutkana Nootka rose B/C 4 75 Symphoricarpos albus Snowberry B/C 4 75 B= bareroot, C= container Total 370 Plants shall be placed on four to eight foot centers. Each plant shall be placed in a hole and backfilled with native soil. Plants shall be grouped in irregular clusters in sizes suitable to the elevation and hydrology as specified in the planting plan. Actual planting shall follow the digging of holes as closely as possible to prevent drying excavated soil. Only moist excavated soil shall be used as backfill for plants. Backfill shall be tamped firmly to remove voids in soil. Excess soil shall be smoothed and firmed around plants leaving a slight depression to collect water. All plants will be watered immediately after planting unless soils are heavily wet. 4.7 Monitoring and Maintenance An as-built report shall be provided to Whatcom County and the Corps within 90 days after the planting phase of the project is complete. The as-built report shall document where minor site design changes were necessary and the final planting schedule. Monitoring shall occur over a ten year period following installation, in years 1, 2, 3, 5, 7, and 10. Whatcom County Parks staff intends to perform monitoring of the mitigation project. Site visits for collecting the vegetation monitoring data will occur in the summer to document if the project is meeting the, goals, objectives, and performance standards. The monitoring report shall evaluate the project s success based on the project performance standards contained in this report. The report shall also include the number of plants in place and documenting photographs. Data from these and the vegetative analysis will be summarized in a technical report and provided to regulatory agencies no later than December 31 st of each monitoring year. All phases of the installation of the mitigation project shall be supervised in the field by a qualified biologist. The selected biologist shall consult with Michele Bodtke and/or Molly Porter of NES at the beginning of the project and regarding any changes related to site preparation, excavation, planting plan and/or maintenance. BAY HORIZON PARK 16

20 The applicant shall provide the maintenance activities detailed in this report and subsequent annual monitoring memos. Maintenance shall be performed as specified, each year, for ten years after the as-built report is approved. Table 14. Ten Year Maintenance Tasks Task Description Schedule Weed suppression* Mow or weed whack. No chemical controls shall be used on-site. Quarterly in Yrs 1, 2 Bi-annual in Yr 3 Annual in Yrs 4, 5 Replace dead plants Remove trash Irrigation Request plant substitutions if necessary New plant material shall be irrigated, if possible, once per week whenever less than one inch of rainfall occurs over any two-week period from June 1 through August 15; and once every other week from August 16 through September 30, for the first year after installation. As needed in Yrs 6-10 All in Yr 1 Replace to achieve 80% survival Annually Yr 1 Remove Vole Protectors Remove even if photodegradable Yr 3 *Weeds include invasive species listed in Table 5 above, and any grasses that may out-complete installed vegetation. 4.8 Contingency Plan All phases of the installation of the mitigation project will be supervised in the field by a qualified biologist and/or restorationist. The selected biologist will consult with Michele Bodtke and/or Molly Porter of NES at the beginning of the project and regarding any changes related to site preparation, planting plan and/or maintenance. If there is a significant problem with the mitigation achieving its performance standards, the County Parks Department shall work with Whatcom County Planning and Development Services and the Corps to develop a Contingency Plan. Contingency Plans can include, but are not limited to: additional plant installation, erosion control, modifications to hydrology, and plant substitutions of type, size, quantity, and location. Such Contingency Plan shall be submitted to the above regulatory agencies by December 31 of any year when deficiencies are discovered. BAY HORIZON PARK 17

21 APPENDIX A: LITERATURE REVIEWED

22 Literature Reviewed Brinson, M A Hydrogeomorphic Classification for Wetlands. U.S. Army Corps of Engineers, Washington D.C. Tech. Report WRP-DE-4. Environmental Laboratory Corps of Engineers Wetland Delineation Manual. Technical Report Y Army Waterways Experiment Station, Vicksburg, Mississippi. Gretag-Macbeth Munsell soil color charts. New Windsor, New York. Hitchcock, C.L. and A Cronquist Flora of the Pacific Northwest. University of Washington Press. Seattle, Washington. Hruby, T Washington State Wetlands Rating System: Western Washington. Washington Department of Ecology, Olympia, Washington. Publ. # Reed, R.B. Jr National List of Plant Species that Occur in Wetlands: 1988 Northwest. Biological Report 88 (26.9), U.S. Fish and Wildlife Service, St. Petersburg, Florida. Reed, R.B. Jr Supplement to the List of Plant Species that Occur in Wetlands, Northwest (Region 9). Supplement to Biological Report 88 (26.9), U.S. Fish and Wildlife Service, St. Petersburg, Florida. U.S. Army Corps of Engineers Interim Regional Supplement to the Corps of Engineers Wetland Delineation Manual: Western Mountains, Valleys, and Coast Region, ed. J.S. Wakeley, R.W. Lichvar, and C.V. Noble. ERDC/EL TR Vicksburg, MS: U.S. Army Engineer Research and Development Center. USDA, NRCS Whatcom County Area Hydric Soil List. United States Department of Agriculture, Natural Resource Conservation Service. [ USDA, NRCS Soil Survey of Whatcom County Area, Washington. United States Department of Agriculture, Natural Resource Conservation Service. [ USDA, NRCS Field Indicators of Hydric Soils in the United States, Version 6.0 G.W. Hurt and L.M. Vasilas (eds.). USDA, NRCS, in cooperation with the National Technical Committee for Hydric Soils. Lincoln, Nebraska. Washington State Department of Ecology Using the Wetland Rating System in Compensatory Mitigation. Washington State Department of Ecology, Olympia, Washington. Publ. #

23 Washington State Department of Fish and Wildlife SalmonScape. Olympia, Washington. [ Whatcom County Planning and Development Services. 2005a. Critical Areas Ordinance: Fish Habitat Conservation Areas GIS Map. Bellingham, Washington. Whatcom County Planning and Development Services. 2005b. Critical Areas Ordinance: Wildlife Habitat Conservation Areas GIS Map. Bellingham, Washington. Whatcom County Planning and Development Services. 2005c. Whatcom County Critical Areas Ordinance: Article VI Bellingham, Washington.

24 APPENDIX B: FIGURES

25 Review Area Detail N ECOLOGICAL NORTHWEST Vicinity Map Bay Horizon Park Whatcom County Parks Mitigation Report Figure 1 May 2009

26 Figure 2 May 2009 ECOLOGICAL This area was not delineated by NES Stream NORTHWEST Existing Conditions and Wetlands Map Bay Horizon Park / Whatcom County Parks Mitigation Report Project Area, for Detail see Figure 3 Map Drawn by: Whatcom County Parks and Recreation Wetland A Wetland C Wetland B Un-flagged Wetlands Wetland D Wetland F Wetland E Wetland K Wetland G Wetland J Wetland H-1 Wetland I Wetland H-2

27 Figure 3 May 2009 Wetland F Wetland F Wetland G Wetland Map for the Project Area Wetland H-1 Wetland H-2 ECOLOGICAL NORTHWEST Bay Horizon Park / Whatcom County Parks and Recreation Mitigation Report

28 Proposed pedestrian bridge Figure 4 May 2009 Public trail access and utility easement Wetland F Wetland F Wetland G APPROX. 8 TRAIL Trails are installed south of this point. The alignment to the north is proposed. Wetland H-1 Proposed Site Plan Bay Horizon Park / Whatcom County Parks and Recreation Mitigation Report ECOLOGICAL NORTHWEST Impacted Area Buffer Impact Wetland Impact Impact s.f. 6,790 4,041 Proposed pedestrian bridge Wetland H-2

29 Figure 5 May 2009 Area A Area B Area B Wetland F Area A Area C Wetland F Wetland G Areas D Area E Area E APPROX. 8 TRAIL Wetland H-1 Impacted Area Buffer Impact Wetland Impact Impact s.f. 6,790 4,041 Conceptual Mitigation Map Bay Horizon Park / Whatcom County Parks and Recreation Mitigation Report Wetland H-2 Wetland Enhancement Area Buffer Enhancement Area NGPA Sign ECOLOGICAL NORTHWEST

30 APPENDIX C: MONITORING CONTRACT

31 Northwest Ecological Services, LLC May 28, 2009 Lynne Givler Whatcom County Parks 3373 Mt Baker Highway Bellingham, WA Dear Ms. Givler, The following letter details the scope of work and cost estimate for Northwest Ecological Services, LLC (NES) to perform biological supervision and an as-built per Whatcom County Critical Areas requirements for the mitigation project associated with the Bay Horizon Park Trail, in Whatcom County, Washington, WA (SEC 31, T40N, R01E W.M.). This contract includes the following tasks necessary to satisfy requirements detailed in the Whatcom County Critical Areas Ordinance and by the U.S. Army Corps of Engineers: Biological Supervision As-Built Report The following is a brief description of the tasks and a time and costs estimate. SCOPE OF WORK 1). Biological Supervision Supervision and consultation with Parks staff and other contractors during the installation phase of the mitigation project to ensure the project is installed per the approved mitigation plan. This task assumes a maximum of five hours of staff time. 2). As-built Report - NES will prepare and submit a technical report to the Client and Whatcom County Planning, and the Corps after completion of mitigation installation. At a minimum, the report will include a map showing plant locations and quantities Cornwall Avenue, Suite 313, Bellingham, WA T/F:

32 PROJECT COST The cost for NES to perform biological supervision during mitigation installation and produce an as-built report shall not exceed $1, Biological Supervision (5 hours at current rate): $ As-built: $1, This bid is good for 30 days. If acceptance is not received by Northwest Ecological Services within 30 days of this dated letter, the bid is then void. If you have any questions about this proposal please call me at (360) Sincerely, Molly Porter Enc. Acceptance of Consultant Services

33 Northwest Ecological Services, LLC ACCEPTANCE of CONSULTANT SERVICES I,, have reviewed the project description and bid provided in the accompanying letter. Northwest Ecological Services, LLC (NES) is authorized to proceed with biological supervision and an as-built report for the Mitigation Plan prepared by NES for the Bay Horizon Park Trail, in Whatcom County, WA, as detailed in the above letter, dated May 28, 2009, with total charges for services not to exceed $1, The NES standard hourly rate shall apply to additional site visits. Client agrees that the professional services provided by NES for this project are for the purposes of improving the subject real property and are therefore lienable under RCW The Client will be liable for all collection charges, including attorneys fees, on all past due amounts. A fifty dollar ($50.00) late fee will be charge for every thirty (30) days past due. Wetland delineations and determination are based upon protocols defined in manuals and publications produced by Federal, State and Local agencies. The methodology used by NES for contracted services is consistent with the routine on-site determination method described in the Washington State Wetland Identification and Delineation Manual, Corps of Engineers Wetland Delineation Manual (1987), and subsequent updates. I understand that the conclusions and opinions given by NES are based upon best professional judgment for current and existing circumstances. No guarantees are given by NES that work product determinations will concur with those performed by regulatory agencies or other qualified professionals. NES owns all materials produced by NES and its sub-consultants associated with the services described herein. The materials may not be changed or altered by anyone without the express written permission of NES. The Client shall hold harmless and indemnify NES from all claims, losses, expenses, fees, including attorney fees, costs and judgments resulting from the unauthorized use of any materials prepared by NES or its sub-consultants. The Client agrees to indemnify and hold harmless NES from all claims, losses, expenses, fees including attorney fees, costs, and judgments that may be asserted against the Client that result from the acts or omissions of the Client or the Client's employees, if any, and the Client's agents. NES agrees to indemnify and hold harmless the Client from all claims, losses, expenses, fees including attorney fees, costs, and judgments that may be asserted against NES that result from the acts or omissions of NES or NES s employees, and NES's agents. If claims, losses, expenses, fees including attorney fees, costs and judgments result from the concurrent acts or omissions of 1229 Cornwall Avenue, Suite 313, Bellingham, WA T/F: