6920 SEAWAY BLVD 2018-01-01 MF Import

Env. Doc. - Fluke Page -7- 2. Phase II Development Requirements: A. Detailed drawings, in accordance with City Design and Cons[ructian Standards, shall be submitted to the Public Works Department shoving site parking layou[, landacaping, utilitiee, storm drainage, temporary conetruction erosion control, and all required improvements in the public right-of-way. Public Works Departaent approval of these drawings is required prior to any permite being iseued. All improvements shall be completed, approved, and warran[ed before the Occupancy Permit is iseued. B. Par[icipation in the cost to fund the Area 5 Sewer Interceptor is required. The actual cost shall be computed by the Building Department per the ordinance in effect at the time and according to the Inforoation prnvided on the approved plans on the date of pecmit issuxnce. ' C. The South Everett Drainage Basin Plan established a goal of contrciiing the peak flow rate in Powdermill Gulch to the existing two year storm. This proposal is within the Powdermill Gulch Drainage Basin and [htrefore a detention facility muet be constructed with a maximum ou[flow rate equal to the exis[ing peak two year storm ra[e of runoff. The facility must be sized to detain a developed 25 year storm. Preliminary information indicates that the area propoaed for the Phase II parking lot naturally drains to the west into the existing stream vhich is tributary [o Povderoill Gulch. The Phase II building area na[ural drainage is [o the existing detention pond. Since all surface wa[er muet be discharged at its na[urally •occurring location, [wo on-site detention systema will be required for this proposal. The existing detention pond mus[ be expanded to provide for drainage from the Phase II building area. For the Phase II parking lot area drainage, and for future phases, an additlonal deten[ion facili[y will be constructed [o � the vest of the Phase II parking area. This detention pond must be constructed in compliance with [he Eollowing requirements: a. The den[ention pond, including the access road, shall be constructed in compliance with recommmendatlons of a soils report prepared by a licensed Soils Engineer. b. The pand shall retain some water year-round and not be drained dry. c. The native vegetation shall be retained or replanted around the pond. d. The outfall ditch shall be vegetated and provide a corridor to the point where it discharges into receiving waters. `,/�J