Critical Areas Study Ludwig Road Preliminary PRD 820 Ludwig Road, Snohomish, WA Parcels , , &

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1 September 17, 2018 Skip Coddington GSC Development, Inc. PO Box 1623 Woodinville, WA AOA-5405 SUBJECT: Critical Areas Study Ludwig Road Preliminary PRD 820 Ludwig Road, Snohomish, WA Parcels , , & Dear Skip: On January 25, 2018 I conducted an initial wetland reconnaissance on the subject property utilizing the methodology outlined in the May 2010 Regional Supplement to the Corps of Engineers Wetland Delineation Manual: Western Mountains, Valleys, and Coast Region (Version 2.0). Additional field investigations were conducted on March 15 and March 20, All of the site reviews were conducted during periods of heavy precipitation. The eastern portion of the site is currently developed with an existing single-family residence and several associated out-buildings. An unmaintained pasture that slopes gently to moderately down from east to west occupies the majority of the remainder of the property. A large electric transmission line traverses the northeast portion of the site and a recently installed sanitary sewer line crosses the western portion of the property. Cemetery Creek flows from north to south through a ravine in the far western portion of the property. 1.0 EXISTING CRITICAL AREAS In addition to Cemetery Creek and two associated short tributary streams, four wetlands (Wetlands A, B, C, and D) were identified and delineated in the western portion of the site during the field investigations. All of the wetlands were subsequently surveyed and are depicted on Drawing W1.

2 Skip Coddington September 17, 2018 Page 2 Attachment A contains data sheets prepared for representative locations in both the wetlands and uplands. These data sheets document the vegetation, soils, and hydrology information that aided in the wetland boundary determination. 1.1 Wetland A Wetland A (21,664 s.f.) is located on a gentle slope in an unmaintained pasture in the southwest portion of the site immediately adjacent the east side of the sanitary sewer line. Hydrologic support to the wetland appears to be from a seasonally high groundwater table. Soils within the wetland were saturated near the surface at the time of the delineation and consisted mostly of a low-chroma silt loam with distinct redoximorphic inclusions. Vegetation within Wetland A consisted primarily of pasture grasses, soft rush (Juncus effusus), creeping buttercup (Ranunculus repens), and patches of Himalayan blackberry (Rubus armeniacus). Wetland A meets the criteria for a Category IV Slope Hydrogeomorphic (HGM) class wetland per the current City of Snohomish rating system. Category IV wetlands require a standard 50-foot buffer per SMC B Wetland B, Cemetery Creek, and Two Small Tributaries Wetland B is associated with Cemetery Creek and is located within a ravine in the far western portion of the property. The wetland is part of a large wetland system that extends off-site to the north and south. The boundary of the wetland on the project site coincides roughly with the toe of the slope and the edge of an impounded beaver pond. In addition, two small (<2 foot wide) seasonal channels appear to originate as seepage on the slope and drain west into the wetland. Vegetation within Wetland B and the riparian corridor of Cemetery Creek included red alder (Alnus rubra), Himalayan blackberry, red-osier dogwood (Cornus sericea), reed canarygrass (Phalaris arundinacea), yellow iris (Iris pseudacorus), giant horsetail (Equisetum telmateia), and skunk cabbage (Lysichiton americanum). Wetland A has been previously approved as a Category II wetland that requires a standard 100-foot buffer per SMC B.2. Cemetery Creek also requires a 100-foot buffer per SMC A. However, since the creek is located entirely within the wetland, the wetland boundary is more restrictive. The two small tributary channels are considered a Type Ns streams and require a standard 35-foot buffer per SMC A. 1.3 Wetland C Wetland C (2,790 s.f.) is located within the unmaintained pasture in the western portion of the site adjacent the east side of the sanitary sewer line. Hydrologic support to the wetland appears to be from a seasonally high groundwater table and soils within the wetland were saturated near the surface at the time of the delineation.

3 Skip Coddington September 17, 2018 Page 3 Vegetation within Wetland C was similar to Wetland A and consisted primarily of pasture grasses, soft rush, creeping buttercup, and patches of Himalayan blackberry. Wetland C meets the criteria for a Category IV Slope Hydrogeomorphic (HGM) class wetland per the current City of Snohomish rating system. Category IV wetlands require a standard 50-foot buffer per SMC B Wetland D Wetland D (2,475 s.f.) is also located within the unmaintained pasture in the western portion of the site adjacent the east side of the sanitary sewer line. Hydrologic support to the wetland is also from a seasonally high groundwater table and soils within the wetland were saturated near the surface at the time of the delineation. Vegetation within Wetland D consisted of an emergent plant community dominated by pasture grasses, soft rush, and creeping buttercup. Wetland D also meets the criteria for a Category IV Slope Hydrogeomorphic (HGM) class wetland per the current City of Snohomish rating system and requires a standard 50-foot buffer per SMC B Functions and Values Wetlands, in general, provide many valuable ecological and social functions, including stormwater storage, water quality protection, groundwater recharge and discharge, and wildlife habitat. The wetlands on the site located within the unmaintained pastures (i.e., Wetland A, C, and D) generally have a lower value for these functions due to their relatively small size, lack of stormwater storage capability, and low structural diversity. Wetland B generally has a relatively high value for most of these functions due to the large size of the overall wetland system and its association with a fish-bearing water. The wetland provides stormwater storage areas that reduce downstream flooding, while trapping sediments. The trapping of sediments and other pollutants within the wetland maintains water quality in downstream areas and aids in the prevention of fish habitat degradation by limiting silt accumulation within spawning areas. The wetland provides further benefit to fish and other wildlife by releasing water slowly during the dry summer months, thereby contributing to the base flow of the stream. In addition to its hydrologic functions, Wetland B also provides significant biological functions. As a component of a large, structurally diverse wetland system, the wetland provides habitat for a wide variety of wildlife species. Another important biologic function of the wetland is the transport of nutrients (via Cemetery Creek) to downstream areas. Nutrients transported to downstream areas provide biological support for fish and other aquatic wildlife.

4 Skip Coddington September 17, 2018 Page 4 Although privately owned, the on-site wetlands do provide some cultural wetland functions as part of the overall open space associated with the site and the Cemetery Creek riparian corridor. The wetlands also contain some passive recreational opportunities such as wildlife viewing. 2.0 CRITICAL AREA IMPACTS As part of the proposed project, Wetland A (21,664 s.f.) would be preserved and provided with a reduced/averaged enhanced buffer that will meet the requirements of SMC The higher value Wetland B and the associated tributary streams and buffers will also be preserved. SMC B.2 states that development within isolated Category III and IV wetlands between 1,000 square feet and 3,000 square feet in area shall be exempt from the normal sequencing process but shall be fully mitigated as required elsewhere in the critical area requirements. Wetlands C and D are both isolated Category IV wetlands < 3,000 s.f. in size. Under the proposed project Wetland D (2,475 s.f.) and a portion of Wetland C (1,331 s.f. ) would be filled for a total wetland impact of 3,806 s.f. SMC E allows for the reduction of a standard wetland buffer by up to 25% if the buffer is degraded and a buffer enhancement plan is implemented. Since the existing buffers of Wetlands A and C currently consist of degraded unmaintained pasture, a buffer enhancement plan will be prepared to allow for the standard 50-foot buffer to be reduced to 37.5 feet in places. This buffer enhancement plan will include the removal of invasive non-native species and the re-planting with a variety of native tree and shrub species to significantly increase the plant species and structural diversity of the buffer. The removal of invasive species and re-planting with native species should increase the habitat value of the buffer over current conditions while also providing screening to the wetlands from the proposed project. The proposed project will also utilize the buffer averaging provisions of SMC F. Buffer averaging is allowed by the City if all of the following criteria are met: 1. The total area contained in the buffer area after averaging is no less than that which would be contained within the standard buffer. As part of the project, 3,542 s.f. of buffer would be reduced and 11,285 s.f. of additional buffer would be provided. In addition, all of the buffer replacement areas would be enhanced as necessary. 2. The buffer averaging does not reduce the functions or values of the wetland.

5 Skip Coddington September 17, 2018 Page 5 The buffer averaging plan will result in a significantly larger overall protected habitat block. In addition, since the current buffers are degraded and do not provide a highly functional benefit to the wetland, the buffer enhancement in association with the averaging will increase the protection and screening functions of the buffer over existing conditions. 3. The wetland contains variations in sensitivity due to existing physical characteristics or the character of the buffer varies in slope, soils, or vegetation. The proposed buffer averaging plan has been designed to provide a significantly larger protected habitat block over existing conditions. In addition, the averaged buffers would provide a connected corridor from Wetland A on-site to the buffer of Wetland B located off-site to the southwest. 4. The director shall have the authority to increase the minimum width of the standard buffer on a case-by-case basis when such increase is necessary. There is no need to increase the standard buffer width on this site. 5. Buffer width averaging does not reduce the original buffer width by more 50 percent at any one point. In no case will the standard buffer be reduced by more than 50% (i.e., 25 feet). 3.0 WETLAND MITIGATION Mitigation for the 3,806 s.f. of wetland impact associated with the filling of Wetlands D and a portion of Wetland C will occur through: 1) the creation of 5,814 s.f. of new wetland connecting Wetland A to the preserved portion of Wetland C and 2) the enhancement of 22,500 s.f. of the existing degraded Wetland A. The proposed mitigation significantly exceeds the minimum mitigation ratios required in SMC J.4. Wetland enhancement will consist of the removal of invasive non-native species and re-planting with a variety of native tree and shrub species to significantly increase the plant species and structural diversity of the wetland. To protect the wetland post construction, a rail-fence would be installed along the outer edge of the wetland buffer.

6 Skip Coddington September 17, 2018 Page Goal, Objectives, and Performance Standards for Mitigation Areas The primary goal of the mitigation plan is to increase the functions of the wetland and buffers on the site over current conditions. To meet this goal, the following objectives and performance standards have been incorporated into the design of the plan: Objective A: Increase the structural and plant species diversity within the mitigation areas. Performance Standard: There will be 100% survival of all woody planted species throughout the planted areas at the end of the first year of planting. Following Year 1, success will be based on an 80% survival rate at the end of Year 5. In addition, there will be at least an 80% areal coverage of native vegetation (including volunteers) at the end of ten years. Objective B: Limit the amount of invasive and exotic species within the mitigation areas. Performance Standard: After construction and following every monitoring event for a period of at least five years, exotic and invasive plant species will be maintained at levels below 10% total cover throughout the planted areas. Objective C Ensure continued wetland hydrology within the created wetland. Performance Standard After construction and following every monitoring event for a period of at least five years, a minimum of 5,814 s.f. of new wetland area on the site will be seasonally inundated or saturated to within 10 inches of the surface for a continuous duration equal or greater than 12.5% of the growing season. 3.2 Construction Management Prior to commencement of any work in the mitigation areas, the clearing limits will be staked and all existing vegetation to be saved will be clearly marked. A preconstruction meeting will be held at the site to review and discuss all aspects of the project with the landscape contractor and the owner. A consultant will supervise plan implementation during construction to ensure that objectives and specifications of the enhancement plan are met. Any necessary significant modifications to the design that occur as a result of unforeseen site conditions will be jointly approved by the City of Snohomish and the consultant prior to their implementation. 3.3 Monitoring Methodology The initial monitoring program will be conducted for a period of five years, with annual reports submitted to the City of Snohomish. In addition, reports will also be provided at the end of Years 7 and 10 to ensure compliance with the 80% areal coverage requirement of native trees and shrubs. Permanent vegetation sampling plots will be established to monitor the general appearance, health, mortality,

7 Skip Coddington September 17, 2018 Page 7 colonization rates, percent cover, percent survival, volunteer plant species, and invasive weeds. Photo-points will be established from which photographs will be taken throughout the monitoring period. These photographs will document general appearance and progress in plant community establishment in the enhancement areas. Review of the photos over time will provide a visual representation of success of the plan. 3.4 Maintenance Plan Maintenance will be conducted on a routine, year round basis. Additional maintenance needs will be identified and addressed following a twice-yearly maintenance review. Contingency measures and remedial action on the site shall be implemented on an as-needed basis at the direction of the consultant or the owner. Routine removal and control of non-native and other invasive plants shall be performed by manual means whenever possible. Undesirable and weedy exotic plant species shall be maintained at levels below 10% total cover within any given stratum at any time during the monitoring period. 3.5 Contingency Plan All dead plants will be replaced with the same species or an approved substitute species that meets the goal of the mitigation plan. Plant material shall meet the same specifications as originally-installed material. Replanting will not occur until after reason for failure has been identified (e.g., moisture regime, poor plant stock, disease, shade/sun conditions, wildlife damage, etc.). Replanting shall be completed under the direction of the consultant, City of Snohomish, or the owner. 3.6 As-Built Plan Following completion of construction activities, an as-built plan for the mitigation area will be provided to the City of Snohomish. The plan will identify and describe any changes in relation to the original approved plan. 3.7 Financial Guarantee A financial guarantee will be posted to ensure that the mitigation and monitoring program is fully implemented.

8 Skip Coddington September 17, 2018 Page 8 If you have any questions, please give me a call. Sincerely, ALTMANN OLIVER ASSOCIATES, LLC John Altmann Ecologist

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43 FigureA Parcels WetlandA WetlandB WetlandC WetlandD HighIntensityHabitat 83% LowModerateIntensityHabitat 4% LowModerateAccessibleHabitat 0% RelativelyUndisturbedHabitat 11% RelativelyUndisturbedAccessibleHabitat 2% ,900 2,850 3,800 USFeet ±

44 FigureBWetlandA Parcels Subject PropertyParcels: / / WetlandA 150' PollutionBuffer for WetlandA PollutionSurfacesfor WetlandA0% SnohomishCounty, WA, Assessor's Office USFeet ±

45 FigureBWetlandC Parcels Subject PropertyParcels: / / WetlandC 150' PollutionBuffer for WetlandC PollutionSurfacesfor WetlandC0% SnohomishCounty, WA, Assessor's Office USFeet ±

46 F ig u rebw e tla n dd PEM only Cowardin Saturated only Hydroperiod P a rce ls S n o h o m ishc o u n ty,w A,A sse sso r'so ffice S u b je ctp ro p e rtyp a rce ls: / / W e tla n dd 'P o llu tio nb u ffe rfo rw e tla n dd P o llu tio ns u rfa ce sf o rw e tla n dd0 % U SF e e t ±

47 FigureC Parcels WetlandA WetlandB WetlandC WetlandD WQA303dCurrent ,840 2,760 3,680 USFeet ±

48 TIMESTAMPS WATER QUALITY IMPROVEMENT PROJECTS (TMDLs) Overview of the process Project Catalog by WRIA by County Water Quality Improvement > Water Quality Improvement Projects by WRIA > WRIA 7: Snohomish WRIA 7: Snohomish The following table lists overview information and links to specific water quality improvement projects (including total maximum daily loads, or TMDLs) for this water resource inventory area (WRIA). Please use links (where available) for more information on a project. Funding Opportunities Counties Project Development Priority Lists Related Information King Snohomish TMDL Contacts RELATED ECOLOGY PROGRAMS Water Quality Waterbody Name Pollutant(s) Status** TMDL Lead Lake Loma Total Phosphorus Straight to implementation project under development Snohomish River French Creek / Pilchuck River Dissolved Oxygen Temperature Tricia Shoblom Under development Ralph Svrjcek Dioxin EPA approved Ralph Svrjcek Estuary Ammonia BOD EPA approved Ralph Svrjcek Tributaries Fecal Coliform Tributaries: EPA approved Ralph Svrjcek

49 Allen Creek Quilceda Creek French Creek Woods Creek Pilchuck River Marshlands (Wood Creek) {2} Snoqualmie River Ammonia-N BOD (5-day) Fecal Coliform Temperature EPA approved EPA approved Has an implementation plan Ralph Svrjcek ** Status will be listed as one of the following: Approved by EPA, Under Development or Implementation For more information about WRIA 7: Waterbodies in WRIA 7 - using the Water Quality Assessment Query Tool Watershed Information for WRIA 7 * The Department of Ecology and other state resource agencies frequently use a system of 62 "Water Resource Inventory Areas" or "WRIAs" to refer to the state's major watershed basins. Back to top of page Last updated January 2014