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SOUNDVIEW TECHNOLOGY CENTER EVERETT, WA <br /> evaluated under the current stormwater manual, which is the 2019 Stormwater Management Manual for <br /> Western Washington, Minimum Requirement#8 Wetlands Protection since these two basins include roof <br /> runoff. Each basin is analyzed below. <br /> Per I-3.4.8, this minimum requirement applies only to TDA's that discharge into a wetland, either directly <br /> or indirectly through a conveyance system.As illustrated below, neither Basin A or Basin B meet this <br /> criteria and therefore this minimum requirement does not apply. <br /> Basin A <br /> Basin A discharges to Japanese Gulch via overland flow through BNSF property to a manmade <br /> conveyance system that begins at the railroad tracks below steep slopes that end at a reginal detention <br /> ponds. From the ponds, runoff is conveyed downstream via pipes, culverts, and open channel ditches <br /> parallel to the railroad bed to Japanese Gulch.Therefore, the project does not discharge to a downstream <br /> wetland. <br /> Basin B <br /> Basin B discharges to an unnamed stream upstream from Edgewater Creek via a combination of natural <br /> swales, constructed swales, tightline pipes, and open channel pipes. See Figure 1 below. Minimum <br /> Requirement#8 is not applicable because the standard applies to "projects that discharge stormwater <br /> into a wetland, either directly or indirectly through a conveyance system." EMC 14.28.060.H. <br /> The project does not directly or indirectly discharge stormwater into any onsite wetland.All onsite <br /> wetlands have been filled per prior permitted work and no longer exist. The project does not discharge <br /> directly or indirectly into an offsite wetland through a conveyance system. Evidence reviewed strongly <br /> indicates the project discharges into an unnamed stream, as identified in the Snohomish County GIS map <br /> system. The outfall into this stream was not found since it is located on private property and the project <br /> could not gain permission from the property owner to search for the outfall. <br /> However, visual observation of the last upstream CB in Lamar Drive indicates a pipe direction that is <br /> directly towards the unnamed stream. Review of contour maps in the City of Mukilteo GIS system also <br /> support the presence of a stream in this location. <br /> See the below Figures 1, 2, and 3 of the municipal conveyance and outfall to the unnamed stream. <br /> SEPTEMBER 23, 2022 STORMWATER DRAINAGE REPORT PAGE 29 <br />