1010 N BROADWAY STARBUCKS 2025-07-24

An Engineering&Woes Company Matrix 1 — Existing Onsite Land Cover Existing Land Cover Modeled Land Cover Area (acres) Landscaping C, Pasture, Mod (1) 0.08 Bioretention Bottom Driveway, Mod (2) 0.07 Area HMA Paving Parking, Mod 0.27 Total 0.42 (1) Bioretention areas are modeled as impervious surface as land cover type. The equivalent area is then input into the bioretention module within WWHM2012 to account for any infiltration and retention capacity provided by the bioretention area. Refer to Appendix E for calculations. (2) Landscaped areas which are to be amended with organic material in accordance with City of Everett/Department of Ecology standards can be modeled as pasture land cover. The project site receives approximately 0.20 acres of run-on area from the parcel immediately to the west. This area is entirely paved asphalt. The offsite run-on area was modeled based upon the land cover areas provided in Matrix 2 below: Matrix#2 — Existing Offsite Run-On Land Cover Existing Land Cover Modeled Land Cover Area (acres) HMA Paving Parking_, Mod 0.20 Total 0.20 7.3 Proposed Land Cover Conditions The proposed development will include a new Starbucks commercial building with associated drive through, parking, exterior pedestrian area, and landscape areas. Grades onsite will continue to slope to the east. Surface water from the west run-on basin will be collected within a gravel interceptor trench located along the west property line and route stormwater to a small bioretention area located at the northwest property corner. Overflow from the bioretention area and a portion of the drive-through lane will be routed to a new detention tank. Stormwater attributed to the Starbucks building and the majority of the remaining site will bypass the detention tank and be routed to the project discharge point located near the center of the north property line. The offsite run-on area is being used as a basin swap to allow for below grade detention that has been limited by the relatively shallow depth of the public storm sewer. Matrix 3 and Matrix 4 below provide the land cover break down for the proposed site conditions. Refer to Appendix A for an exhibit showing the proposed land cover conditions and the calculated land cover areas. Matrix 3— Proposed Area to Tank (Includes Offsite Run-On) Existing Land Cover Modeled Land Cover Area (acres) Landscaping C, Pasture, Mod 0.01 HMA Paving Parking, Mod 0.15 Total 0.16 Starbucks Page 11 Broadway and 10th Store Drainage Report May 2014