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Exhibit A (Scope of Work) <br />Task 7 – Drainage and Stormwater Design <br />This task includes drainage and stormwater design of the proposed roadway <br />improvements. <br />Design Criteria <br />The 2024 Stormwater Management Manual for Western Washington, (SWMMWW), the <br />City of Everett 2025 Design and Construction Standards and Specifications (DCSS), <br />and Everett Municipal Code Chapter 14.28, will be used as the stormwater regulatory <br />guidance for this project. When the 2024 SWMMWW and DCSS are released, the <br />project will update to the latest guidance. The 2012 LID Manual may also be used as <br />guidance. Prior to beginning the project’s stormwater design, a stormwater design <br />criteria matrix will be prepared summarizing all stormwater related requirements and <br />standards. The design criteria matrix will be provided to the City of Everett for review <br />and concurrence prior to beginning design work. <br />Deliverables: <br />• Stormwater Design Criteria Matrix <br />Off-Site Analysis <br />Consultant will conduct a downstream analysis extending ¼ mile downstream/down- <br />gradient of the project right-of-way limits for the Threshold Discharge Areas (TDAs) <br />associated with the project site. The downstream analysis will include a review of City <br />GIS maps, recent drainage complaint documentation provided by the City (if it exists), <br />and an assessment of downstream routes to identify evidence of erosion, flooding, <br />sedimentation, or flow constriction points. A limited visual above-ground inspection will <br />be conducted given the very steep slopes and dense forest present along the <br />downstream route. The assessment of the downstream effects is to be a qualitative <br />evaluation based upon engineering judgment and any information available on the <br />downstream systems that the City can provide. Consultant will prepare a written <br />description of the downstream system conditions and provide a map showing the <br />downstream drainage route. <br />Consultant will perform a visual inspection of the upstream contributing basin area of <br />the site and provide an estimate of the area draining to the site based upon available <br />mapping data and site visit observation. <br /> <br />This task does not include a detailed review of the upstream basin boundary or land use <br />assessment, or any detailed hydraulic analysis or computations associated with the <br />upstream or downstream basins. <br />Assumptions: <br />• The site lies within three (3) or more distinct TDAs. Therefore, three (3) or more <br />(up to 6) downstream analyses are assumed.