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b. Other innovative downspout control BMPs such as rain barrels, ornamental ponds, <br /> downspout cisterns, dry wells,or other downspout water storage devices may also be used <br /> with prior approval by the City of Everett.These are options to consider after the above <br /> listed BMPs are evaluated. <br /> 2. Determine which options you must use for managing stormwater from hard surfaces (driveways, <br /> paved pathways, etc.) by considering the following for each type of hard surface proposed: <br /> • BMP 12.60 Concentrated Flow Dispersion <br /> • BMP 12.70 Sheet Flow Dispersion <br /> Note: Propose an alternative stormwater management plan if none of the above BMPs can feasibly be <br /> installed. (Examples:Shallow vegetated swale, perforated pipe stub-out, etc.) <br /> Provide your Evaluation below and Show where these will take place on a site map: <br /> 1. Rooftop Drainage Management. The existing building and the proposed <br /> south addition are situated along the edges of the proposed parking lot to west. The <br /> existing and proposed rooftops slope on all sides; and therefore, little opportunity is <br /> provided for dispersion of downspouts on the west side of the buildings other than <br /> rain barrels to provide at least some detention where there is room at the northwest <br /> corner of the existing building. This must be done at the project completion as <br /> directed by the engineer. The south side of the proposed building is too close to the <br /> property line, but paving blocks are called out for a proposed pathway which can be <br /> embedded in gravel (rounded washed gravel) in contact with the prepared native soil <br /> as subgrade. The proposed south storm catch basin will provide for overflows. The <br /> east and north side of the buildings, however, provide ample opportunity for soil <br /> amendment for the entire existing lawn area, and rain barrels for each downspout. <br /> Since this work is typically done by a landscape contractor, we prefer this to be <br /> stipulated near the project completion to be directed by the engineer in accordance <br /> with BMP 12.50 and BMP 12.20 prior to occupancy permit. Rain gardens are not <br /> recommended in an apartment environment due to potential neglect and abuse. <br /> 2. We have selected sheet flow dispersion from the proposed parking lot <br /> pavement directly onto the grass filter strip, BMP 12.70, as shown on the civil plans. <br /> Page 4 of 7 <br /> CITY OF EVERETT 13200 Cedar Street I Everett, WA 98201 I 425-257-8810 I everettwa.gov <br />