6708 CADY RD 2025-03-31 - Laserfiche WebLink

DOWNSTREAM ANALYSIS Task 1. Study Area Definition and Maps Snohomish County Bare Earth LiDAR, survey, and 2012 aerial photography were the best topographical references available for the area containing the site. The limits of the downstream analysis extend roughly 0.25 miles beyond the subject property's discharge location (see the Downstream Map in Appendix 2). Task 2. Resource Review All of the resources below have been reviewed for existing and potential issues near the project site: • Drainage Basin This site is located within Puget Sound Drainages. Runoff from the proposed development will eventually discharge into Pigeon Creek which then discharges into Puget Sound. • Floodplain / Floodway (FEMA) maps According to FEMA floodplain mapping, the subject property is not within a floodplain. Reference the FEMA FIS study map 53061C1040G. • Critical Areas Map City of Everett critical areas mapping does not indicate any streams, wetlands, landslide hazards, erosion hazards, or any other critical areas on site or adjacent to the site. • Drainage Complaints According to the pre-app comments, there are three known drainage issues downstream of the site. See further discussion under Task 4. • Road Drainage Problems No road drainage problems were observed during the downstream site investigation. • USDA Soil Survey According to the NRCS Soil Survey, site soils are primarily characterized as 100%Alderwood-Urban land complex with 2 to 8 percent slopes. • Wetland Inventory Maps According to the City of Everett GIS Maps, there are no wetlands or buffers within the site. • Migrating River Studies Migrating River Studies are not applicable to the proposed site development. • Section 303d List of Polluted Waters Washington State Department of Ecology's Water Quality Assessment does not include any Category 5 303d listings within 0.25 miles of the site. • Water Quality Problems No water quality impairments driven by pollutants were found in receiving waters within 0.25 miles of the site. • Stormwater Compliance Plans Not applicable to the proposed project. Task 3. Field Inspection/Downstream Analysis(See the Downstream Map in Appendix 2) On May 2nd, 2023, a Downstream Analysis was performed at the site. The weather consisted of 680F and clear skies. The following observations were verified during the visit. Upstream Area: Due to the flat topography, the surrounding parcels do not appear to contribute any notable amount of upstream runoff. Downstream Flow Path: The runoff from the area of the site where the Pallet Shelters will be constructed is dispersed onsite across a large, flat, vegetated area. Stormwater from the eastern, developed portion of the site enters the city conveyance system along the Cady Rd and Madison Street frontages and converges at the intersection of those two streets. From here, the downstream flowpath travels roughly 800 ft eastward along Madison Street, before traveling roughly 1,250 ft north along Evergreen Way and leaving the quarter-mile buffer. Eventually the flowpath discharges to Pigeon Creek which then discharges into Puget Sound. Service ABOVL the Standard