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ESA The Woodlands Review Memo_2020_0207 February 7, 2020 Becky Chapin – City of Federal Way Community Development Department Jessica Redman, Wetland Ecologist Critical Areas Report Review: The Woodlands at Redondo At the request of the City of Federal Way (City), Environmental Science Associates (ESA) reviewed the critical areas report prepared by Sewell Wetland Consulting Inc. for the property located off of Pacific Highway South and South 304th Street (Tax Parcels 042049012 & 042049221) in Federal Way, Washington. The applicant proposes to construct a 68 lot residential subdivision with associated infrastructure, including a stormwater detention pond. The property is located approximately 460 feet northeast of Steel Lake, which is designated as a Shoreline of the State. ESA previously reviewed an earlier version of the critical areas report (dated June 20, 2019) and conducted a site visit on August 28, 2019 to review the wetland boundary and the submitted rating form. Findings were presented to the City in the technical memorandum titled Critical Areas Report Review: Parcels 042049012 & 042049221 (dated September 6, 2019). ESA also previously reviewed critical areas on the adjacent parcel to the southwest (Tax Parcel 0421049057) in January 2016 which resulted in the delineation of one wetland and one stream, both of which extend onto the parcels currently being reviewed. Results of the January 2016 review by ESA were presented to the City in the technical memo titled Jung Property Wetland and Stream Assessment for Parcel 0421049057 (dated January 26, 2017). Review of Documents ESA reviewed the Critical Areas Report – Woodlands at Redondo (dated October 11, 2019 and hereinafter referred to as the Report) prepared by Sewall Wetland Consulting, Inc. (hereinafter referred to as the Applicant’s Biologist). The Report was written based on site evaluations by the Applicant’s Biologist that occurred on May 22, 2019. The Preliminary Plat for the Woodlands at Redondo Creek Plan Sheets (dated October 22, 2019 and hereinafter referred to as the Plan Sheets) prepared by ESM Consulting Engineers, were also a part of this review. According to the Report, one wetland occurs onsite and is located along the western edge of the site. The wetland is a riverine and depressional wetland that exhibits forested, scrub-shrub, and emergent cover types. The wetland is associated with Redondo Creek, which flows through the center of the wetland as a channelized, ditch-like feature. The stream originates from Steel Lake and flows north, under South 304th Street through a 30-inch plastic culvert, and into the site. Though not stated in the Report, the onsite wetland is considered an “associated wetland” of Steel Lake due to its hydrologic connection via Redondo Creek and therefore, is regulated under the Critical Areas Report Review: The Woodlands at Redondo 2 City’s Shoreline Master Program (SMP), which references the critical area regulations under Chapter 19.145 of the Federal Way Revised Code (FWRC). During a review of the property south of South 304th Street, the City determined that Redondo Creek is a “minor” or non-fish bearing stream, due to a natural fish barrier that is located downstream of the site. The Report is in agreement with this determination and states that the stream is a non-fish bearing stream with seasonal flow (Ns) and is allotted a 35-foot buffer per FWRC 19.145.270.1. The wetland was categorized as a Category II wetland with 6 habitat points. According to FWRC 19.145.420.2, Category II wetlands with 6 habitat points are allotted a 150-foot buffer, which greatly exceeds the required stream buffer. To accommodate the proposed development, the applicant proposes to reduce the wetland buffer by 18,674 square feet (SF) on its northern side, near the upstream portion of the wetland. An additional 19,188 SF of buffer will be added to the northern side of the wetland buffer further downstream, resulting in a net increase of 514 SF of wetland buffer. According to the Report, the proposed buffer averaging meets all the required criteria per FWRC 19.145.440.5. Additionally, the Report states that the City-required widening of South 304th Street will also result in some wetland buffer impact. The amount of impact is not specified in the Report; however, according to the Plan Sheets it appears that a 9-foot addition to the existing right-of-way north of S 304th Street is proposed. According to the Report, this portion of the buffer is substantially modified by existing stormwater infrastructure, transient use, and fill; and therefore, buffer reduction should be considered by the City for this portion of the buffer per FWRC 19.145.440.4 – Permanently Altered Buffer. Review Findings Based on the site visit and the document review, we have the following comments and recommendations:  As mentioned in our September 6, 2019 technical memo, ESA agrees with the wetland delineation boundaries and OHWM established by the Applicant’s Biologist. ESA also agrees with the wetland classification (Category II with 6 habitat points) assigned by the Applicant’s Biologist and that the wetland is allotted a 150-foot buffer per FWRC 19.145.420.2.  ESA agrees that reach for Redondo Creek within the proposed project parcel is a non-fish bearing seasonal stream and therefore, is allotted a 35-foot buffer per FWRC 19.145.270.1.  ESA agrees that the proposed Project has met all the requirements for buffer averaging per FWRC 19.145.440.5 – Buffer Averaging. However, according to the Report, the area proposed for buffer addition “is mature forest with some transient impacts but generally less than the reduction area.” ESA recommends that the applicant propose buffer enhancement in the buffer addition area to ensure that buffer averaging does not result in a loss of ecological function. Appropriate buffer enhancement strategies include the removal of refuse, invasive plants, and the subsequent planting of native vegetation, where appropriate.  ESA does not agree that buffer reduction is an appropriate alternative for the portion of the wetland buffer to be impacted by the widening of South 304th Street. According to FWRC 19.145.440.4(4) – Permanently Altered Buffer, buffer reduction may be considered by the Director “when existing Critical Areas Report Review: The Woodlands at Redondo 3 conditions are such that portions of the required buffer exist in a permanently altered state (e.g., roadways, paved parking lots, and permanent structures) and do not provide any buffer function.” ESA agrees that the portion of the buffer adjacent to the road has been permanently impacted by the road and stormwater infrastructure (i.e. culvert). However, during the August 28, 2019 site visit, this portion of the buffer included a vegetated road shoulder and road prism (see photograph below); and therefore, still provided some level of ecological function to the wetland, primarily the filtering of pollutants and sediment from road runoff before entering the wetland. Based on a discussion with you, we understand that the impacts to the wetland buffer are viewed as a result of the City-required road widening and therefore should be reviewed under FWRC 19.145.120 – Public Exemptions. This code provision states that “the director may permit the placement of an essential public facility or utility or other public improvements in a critical area if no practical alternative with less impact on the critical area(s) exists.” Under this exemption, the City still requires mitigation for any impacts to critical areas. ESA recommends that the applicant revise the Report and Plan Sheets to include a mitigation plan for the buffer impacts as required by FWRC 19.145.140 – Mitigation Plan Requirements. We also recommend that mitigation be focused on protecting the wetland and stream from possible impacts caused by the road widening and may include installing native plants in the wetland or wetland buffer. Additional vegetation in these areas would increase the water quality and hydrologic functions of the already reduced buffer, as well as hamper the possible disposal of refuse by passersby. Photograph 1. Vegetated road shoulder (stream in background) along S 304th Street (Source: Google Maps. Image Date – November 2018).