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Home My WebLink AboutWetland Delineation 501041038 , - i . l l I I I f5) [E (C [f~ w [E r~1 Ifj'lIMAY 24 2006 IlU.)1 INTRODUCTION I 1_ _. , -.J i Ecological Land Services, Inc. (ELS) was contracted by Bosworth-HoedJdli1ker, Architects t~_,~ delineate any wetlands in proximity to the house on the Driscoll-Hoffman property, parcel number 50]041038, located in a portion of the Southwest y., of Section 4, Township 25 North, Range I West, Willamette Meridian on the Toandos Peninsula in Jefferson County, Washington (Figure I), The owners of the property propose to demolish the existing house and build a new one in the same area, SITE DESCRIPTION The subject site contains an existing house overlooking Hood Canal to the south, A one lane gravel driveway provides access to the house from both east and north, To the west of the house is a pond, delineated as a jurisdictional wetland, separated by a natural berm from Hood Canal. A concrete boat house is located adjacent to the pond, A driveway provides access to the boat house trom the other driveway north of the house. There are low density single family residences to the north, and east of the site, Figure 2 attached, shows the relative location of these features. The house is estimated to be approximately 30 feet higher in elevation than the pond, The pond and house, separated by a driveway and a vegetated slope, are more than 100 feet apart horizontally, The on-site wetland is an open water/emergent wetland that is dominated by burreed (Sparganium sp,) and cattail (Typha la/i/olia), The wetland delineation focused on the eastern side of the wetland as it is the closest part of the wetland to the existing house, The edge of the wetland in this area is well-defined and abutted by a maintained mowed area and/or old road till associated with the access driveway to the boat house and shoreline, METHODS The wetland delineation completed by ELS followed the Routine Determination Method according to the U,S, Army Corps of Engineers, We/lands Delinea/ivn Manual (Environmental Laboratory 1987) and the Washington State Department of Ecology, Washing/on S/a/e We/lands Iden/ifica/ion and Delinea/ion Manual (1997) The Routine Determination Method examines three parameters - vegetation, hydrology. and soils _ to determine if wetlands exist in a given area, Hydrology is critical in determining what is wetland. but it is otten difficult to assess because hydrologic conditions can change periodically (hourly, daily, or seasonally), Consequently, it is necessary to determine if hydrophytic vegetation and hydric soils exist, which would indicate that water is present for long enough duration to support a wetland plant community, By definition, wdlands are those areas that are inundated or saturated by surface or ground water at a frequency and duration sufficient to support, and that under normal circumstances do support, a prevalence of vegetation typically adapted for life in saturated soil conditions, Wetlands are regulated as Bosworth Hoedemaker Driscoll- HotTman Wetland Detertnination Report Ecological Land Services, Inc. March 8.2005 -1- "Waters of the United States" by the U.S, Army Corps of Engineers, as "Waters of the State" by the Washington State Department of Ecology, and locally by Chapter 18.15 Jefferson County Code (JCC) of Jefferson County, Washington. ELS evaluated the property on 25 January, 2005. An open water/emergent wetland was delineated in the southeast portion of the property, west of the existing house. The eastern side of the wetland was flagged with fluorescent-orange flagging and pin flags, Vegetation, hydrology, and soil data were collected from paired test plots to verify the wetland boundaries (see attached), VEGETATION Dominant vegetation found on-site is recorded on the attached routine wetland determination data sheets. The indicator status, following the scientific names, indicates the likelihood of the species to be found in wetlands. Listed from most likely to least likely to be found in wetlands, the indicator status categories are: . OBL (obligate wetland) - occur almost always (estimated probability >99%) under natural conditions in wetlands. · FACW (facultative wetland) - usually occur In wetlands (estimated probability 67%- 99%). but occasionally found in non-wetlands, . FAC (facultative) - equally likely to occur In wetlands or non-wetlands (estimated probability 340/0-66%), · FACU (facultative upland) - usually occur in non-wetlands (estimated probability 670/0- 99%), but occasionally found in wetlands (estimated probability 10/0-33%). · UPL (obligate upland) - occur almost always (estimated probability >99%) under natural conditions in non-wetlands, . NI (no indicator) - insufficient data to assign to an indicator category, The on-site portion of the wetland is predominately open water with some emergent vegetation present. The dominant vegetation species are burreed (Sparganium sp,. GBL). common cattail (Typha la/ifiJlia, GBL) and spike rush (Scirpus atrocinctus. GBL), The uplands are dominated by an overstory canopy of Douglas fir (Pseudotsuga menziesii, F ACU) and western red cedar (Thuja plicata, F AC), with a mid-understory layer of evergreen huckleberry (Vaccinium ova/um, FACU). and with a mixed herbaceous layer ofswordfem (POlyslichum munitum, FACU and salal (Gaultheria shal/un, FACU) in the low understory. Bosworth Hoedemaker Driscoll- Hoffman Wetland Detennination Report IB) rE [; [E ~ \t~ ~\I lr11MAy 24 r, !I; L_,.~, - 2- 1...,....1/"0, Ecological Land 1Si:&iees,Jnc,___, March 8, 2005 . I I I I I I I ! ! I . ,. I~ f ~ [E""l W IE fR\\ ill Ii! MAY24 2O~IUJ\ SOILS The on-site soils of the delineated wetland area are mapped as Cassolary-Everett complex (ChD) 1-30 % slopes, as referenced by the U,S.D.A, Soil Conservation Service for Jefferson County Area, Washington (1975) (Figure 3), The Cassolary-Everett soils are about 60 percent Cassolary sandy loam and 40 percent Everett gravelly sandy loam. The Cassolary series consists of well-drained soils on upland terraces and were formed in reworked glacial and marine sediments, The State of Washington Hydric Soils Lis/ for Washing/on does not identify the Cassolary-Everett soils as hydric (Soil Conservation Service 1995). Mapped hydric soils do not necessarily mean that the area is a wetland; hydrology, wetland vegetation, and hydric soils must all be present to classify an area as a wetland. Conversely, wetlands may be found in areas where the soils are not mapped as hydric, The upland soil in Test Plot] exhibited a mixed clay loam and silt loam soil type. The plot did not confirm the mapped soil type however the test pit was dug in an area from which the existing road was excavated out of the slope, therefore it may have been' originally subsoil. Test Plot 2 within the wetland was inundated with water and therefore no soil test pit was dug, HYDROLOGY The delineated wetland was inundated by water an estimated 0.5 to 2.5 feet deep, WETLAND INVENTORIES NATIONAL WETLANDS INVENTORY The National Wetlands Inventory (NWI) mapped the on-site wetland as a palustrine unconsolidated bottom permanently flooded wetland (PUBHH) (Figure 4). The ELS- delineated wetland concurs with the NWL As a cautionary note, NWI maps are typically used to gather information about a regional area and are somewhat limited in accuracy for smaller sites because of the large scale used with the maps. CONCLUSIONS ELS delineated the boundary of one emergent wetland located on-site west of the existing house, The wetland boundaries were based primarily on a change in vegetation, obvious hydrology and a break in topography, The wetland is dominated by obligate wetland (OBL) herbs, The soils were inundated with water and assumed hydric. The wetland is located in a depression that is lower in elevation than the surrounding uplands, The wetland is maintained by ground water and surface water from a small stream draining from the north, Bosworth Hoedemaker Driscoll- Hoffman Wetland Detenninalion Report Eco,lW~i ~d ~rv~-=rn:l1E ~ 'n1/ March8.2o;~IUII , '\' MAY 2 4 2006 , / ' I I L-_..____---1 L" - '\cNT j I - 3 - I I I I I I I I I I I l 1 I k The upland buffers adjoining the wetland are dominated by facultative upland (FACU) and facultative (F AC) trees, shrubs, and herbs, The evaluated upland soils are well-drained and lacked hydric soil indicators, The existing buffer between the house and the wetland is already partially disturbed by on-going lawn mowing, an access road, a trail from the house to the shore, and a concrete boat shed. WETLAND CATEGORIZATION AND BUFFERS The on-site wetland was categorized as a Category Il wetland accotding to the Wetland Rating Fonn for Western Washington (Washington Department of Ecology, 2004). Please see rating fonn attached. In accordance with Jefferson County Code 18.15.340, Table 3-4, Category II wetlands require a standard buffer width of 100 feet. The location of the buffer is depicted on the Site Map attached (Figure 2), Demolition and reconstruction of the existing house will not occur within the required butTer. Furthermore, the existing buffer has been interrupted by on-going and existing disturbances as documented above, therefore it does not function as a naturally undisturbed buffer. This report documents the standardized scientific investigation, best professional judgment, and conclusions of ELS and it is our opinion that it should agree with local, state, and federal regulatory agencies, I' k o letl{1~ \ \ 'f r-r::r "() .1: _ "......... , r,t l I'F:~:_.~__.____.__.- I; ... ~ . Boswonh Hoedemaker Driscoll- Hoffman Wetland Detennination Repon - 4- Ecological Land Services, Inc, March 8. 2005 . . . - I I I I I I I I I I I I I I I" I I I . lE~lE~\'U[E II r'~\ MAY 2 4 o 100 200 I I I SCALE IN FEET SCALE IS APPROXIMATE Le~end: I... "'1 ~ Wetland Driveway Existing Trail Test Plot ,/ Tp.1. ECOLOGICAL LAND SERVICES, INC. NATURAL RESOURCE CONSULTING AND LAND PLANNING 1157 3rd Avenue Suite 220 Longview, WA 98632 (360) 578-1371 Fax: (360) 414-9305 DATE 3-7-0S Figure 2 SITE MAP Driscoll - Hoffman Wetland Bosworth Hoedemaker Jefferson County, Washington Section 4 Townshi 25N Ran e lW w'M. DWN. lIT APPR. PROJ. # 1125,01 ~ I L I