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HomeMy WebLinkAboutSpecial Report (007)Olympic Wetland Resources Erica Iseminger 8602 29th Ave NW Seattle, WA 98117 Case #: MLA01-3825 Jefferson County Department Of Community Development Level I Wetland Assessment Erica Iseminger Fawn Meadows Road Chimacum, WA Description of Site · Description: Parcel # 901225009 (Lot 9) and 901225010 (Lot 10) Location: Chimacum, WA, West Valley Rd, to Van Trojan Rd and to Fawn Meadows Rd. At the request ofErica Iseminger, Dixie Llewellin of Olympic Wetland Resources surveyed Lots 9 and 10 on October 16, 2001. A large wetland is indicated on the Jefferson Critical Areas map near the subject property. All wetlands within Jefferson County are subject to the regulations of the Jefferson Count Unified Development Code (UDC) January 2001. The goal of this Level I wetland assessment is to determine approximate wetland edges in relationship to a chosen building envelope and septic siting. Previous history of land use includes a selective harvest of red cedar near the wetland by Vail Case, Miller Shingel Company, Inc. (Application 1998 FPA26-01489, 1998). Signs of logging were still apparent in the cleared areas, including mounded soil, stumps, and 'skid roads. The -wetland was classified as a Class II wetland prior to the logging operation. Class II wetlands have been assigned a protective buffer by the Jefferson County UDC of 150 feet if not delineated, and 100 feet if the edge is defined through a formal delineation. Methodology The following references were consulted for this project: · Jefferson Critical Areas Map Wetlands (1995) Iseminger Wetland Assessment 2001-0888 I Olympic Wetland Resources, linc 10/01 · Soil Survey of Jefferson County (U.s. Soil Conservation Service 1975) · National Wetland Inventory Map · Jefferson County Unified Development Code (January 2001) Fieldwork to determine the actual wetland boundaries was conducted according to the methodology outlined in the Washington State Wetland Identification and Delineation Manual (Department of Ecology ~6-94). Washington Administrative Code requires that all wetlands within the State of Washington be delineated using this manual. The methodology outlined in the manual requires examination of the three parameters for a positive wetland determination: hydric soils, hydrophytic vegetation, and hydrology. For an area to qualify as a jurisdictional wetland it must have a positive indicator from all three parameters. All wetlands identified using this methodology may be federally regulated, regardless of size. A hydric soil is a soil that forms under conditions of saturation, flooding, or ponding, which last long enough during the growing season to result in an anaerobic upper layer. Hydric soils favor the growth and regeneration ofhydrophytic vegetation. The indicators for this type of soil include low chroma, mottles, gleymg, and high organic content within the upper 32 inches of the soil profile. Holes were dug on the site and soil colors (including value and chroma) were recorded for the top 16 inches. Soil colors were analyzed using the Munsell Color Charts (1992). Vegetation Wetland plant species must constitute greater than 50% of the total vegetation present to meet the qualification as a site dominated by hydrophytic vegetation. Dominance of plant species is determined by calculating actual aerial cover within a 30-foot radius for trees, a 10-foot radius for shrubs, and a 6- foot radius for the herbaceous layer at each data point. Commonly occurring plant species have been rated in the United States Fish and Wildlife (USFW) National List of Plant Species that occur in Wetlands: Northwest (Re,on 9), as to their frequency of occurrence in wetlands and non-wetlands. During the fieldwork, each species was recorded and given a rating based on indicator status. Hydrology Wetland hydrology is defined in the Washington State Wetland Identification and Delineation Manual as "areas that are periodically inundated or have soils saturated to the surface at some time during the growing season". Areas must have seasonally inundated or saturated soil at least 12.5% of the growing season. Indicators of hydrology include visual observation of inundation or soil saturation, water- stained leaves, cracking of the soil surface, and/or sediment deposits. Positive si~s of hydrology are often absent during the summer and fall months but can be inferred if there are positive indicators of hydric soil and hydrophytic vegetation. Findings During the site visit on October 16, 2001 positive indicators of the wetland edge were identified and measurements were taken perpendicular from the wetland edge to the proposed building site. Field measurements in relationship to the property boundaries are approximate since exact survey markers were not located. Measurements were taken using a Chainman hip chain in perpendicular Iserninger Wetland Assessment 2001-0888 2 Olympic Wetland Resources, Inc 10/01 lines from the wetland edges to the proposed building site and septic site locations (as indicated by perk holes). Perk hole # 1 lies approximately 120 feet from the wetland edge near the lot line of Lot 9 and 10 to the west. The proposed 3-bedroom residence is and 160 feet from the wetland edge. To the south the wetland edge is over 200 feet from the proposed building site. A map is included with this report indicating field findings. This enclosed map does not represent an exact or formal delineation of the wetland edge. Hydrophytic vegetatiOn was identified in the wetland and includes a tree layer of willows, cedars, and alders. Dominant understory in the wetland consists of dense thickets of salmonberry and rose with Douglas' spirea in the wet areas. Other water-tolerant plants include common rush and field mint. The wetland edge is defined by a transition to less water-tolerant vegetation consisting of ocean-spray, Indian plum, sword fern, salal, rhododendrons, big leaf maple, hemlock, and small Douglas fir. The edge is less clearly defined in some areas. In disturbed areas, where the soil was compacted or altered during the logging process, patches of wetland vegetation were identified. No standing water or surface saturation was observed during this site visit. Jefferson County has been experiencing drought years of late and has had just over half the normal rainfall for this year. There were signs of ponding and water-loving.vegetation in the western section of the site near the property boundary, but it was also dry at the time of the survey. Water only needs to be present 20 days of the growing season for an area to qualify as a wetland. The growing season is defined by the Jefferson County soil survey as March 12 to November 25. Hydrology must be present for 12.5% (20 days) of these 258 days. If there is a question concerning standing water on the property a survey should be conducted toward the end of the wet season. Final authority over wetland determinations rests with Jefferson County Department of Community Development Critical Areas staff. If you have any further question about this project please feel free to call. Sincerely, Dixie Llewellin Principal Biologist, Olympic Wetland Resources, Inc. Certified for Wetland Delineation, 1987 Manual Wetland Training Institute June 1995. Iseminger Wetland Assessment 2001-0888 3 Olympic Wetland Resources, Inc 10/01 Olympic Wefland Resources, Inc. Pod bwnmd, WA 98368 360 38%432 lille: Cried: Erica Iseminger Fawn Meadow Road Level I Wetland Assessmem Erica Iseminger 8602 29th Ave NW Seattle, WA 98117 kale: As Indicated October 2001 ]~#: 01-0888 ~d Map #1 757.80 Lot 9 "~~~-~,, Proposed Gaq/[,~ ~ Dry Area that ~/ '~~~ P¢~k hole # was once Ponde~ '~",,,~ %~ .~~ ~roposed House ~200' ~mmmmmm~ Approximate Wetland Edge' Lot 10 This map does not represent a formal delineation .... wetland edges are approximate.