In lieu fee mitigation plan
Baseline Conditions Site Description and Baseline Conditions
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- Baseline Conditions: Wetlands
Baseline ConditionsSite Description and Baseline ConditionsThe EBR Mitigation Project is located in the riparian zone and historic floodplain of the Cedar River. It consists of 13 residential parcels totaling 11.5 acres split between the right and left banks of the Cedar River. All the properties were previously developed for residential purposes or related activities, but all the homes have been purchased by King County and subsequently demolished and removed. All parcels are owned by King County. The mitigation area on the RB of the Cedar River consists of six small residential parcels. The site is bordered by SE Jones Rd to the north, by Stewart Creek and a previous mitigation project for impacts associated with the Elliott Bridge replacement project to the east, the old right of way and fill prism of the previous Elliott Bridge to the west, and the Cedar River to the south. The RB properties are primarily lawns and residential landscaping with a few mature conifers and a limited number of native and ornamental trees. The RB mitigation area is shown in Figure 5. The mitigation area on the LB of the Cedar River consists of six former residential parcels. The site is bordered by the Cedar River to the north, the City of Renton property to the west, 149th Ave SE and the Madsen Creek hi-flow bypass channel to the east and private residential properties to the south. On the LB site, there is a stand of mature conifers that occupy a portion of three of the parcels. Some of these trees will be cut during construction of the LB off-channel habitat features, but the site will retain most of the mature trees to provide shade, and woody material from the cut trees will be used to create habitat features onsite. The three parcels on the LB are generally open with reed canary grass and other grasses filling in since the homes have been removed. The LB mitigation area is shown in Figure 6: Left Bank Mitigation Area 2013 Aerial Photo. Baseline Conditions: WetlandsEleven wetlands in total were identified and delineated at the EBR Mitigation Project, ten of which are on the left bank and one on the right. Seven were identified by WSDOT and four by Herrera Environmental Consultants (HEC). Both delineators focused their efforts on separate areas of the site and identified their respective wetlands alphabetically (A, B, C, etc.). For the purposes of this report, they have been reassigned designations (i.e. renamed) as shown in Table 2 and mapped in Figure 7. Table 2 Wetland Designations, Classifications, Sizes and Regulatory Buffers
*Wetland size in on-site portion only. ** Total wetland acreage is estimated based on aerial photographs. A. Cowardin et al. (1979) or National Wetland Inventory (NWI) Class based on vegetation: P = Palustrine; EM=Emergent; SS = Scrub-Shrub; FO = Forested. B. Ecology rating according to Hruby (2004). C. King County uses the Ecology Rating System (Hruby 2004). See King County Critical Areas (K.C.C.21A.24.318). D. Wetland buffer widths are according to King County Critical Areas (K.C.C. 21A.24.325). Wetland A on the LB portion of the site will be partially impacted by construction of the off-channel habitat. This impact will be mitigated onsite, and the creation of off-channel habitat will provide ecological functions consistent with the goals for the EBR Mitigation Project and the reach (see goals for the Cedar River per the Program Instrument and goals for the EBR Project in Section II of this Mitigation Plan). One small (0.03 acre) wetland (Wetland G) was identified by WSDOT on the RB at the toe of the existing levee. This wetland is fringe vegetated shallow on the margin of the Cedar River channel located below the Ordinary High Water Mark (OHWM). WSDOT did not provide any description or classification of this wetland since it is within the Cedar River. However, the area shares characteristics with the aquatic margin habitat that will be created in the immediate vicinity along the right bank channel edge. Download 7.62 Mb. Share with your friends:
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