B2 split drain

1. Stormwater management plan Duncan Residence | SE Ash Ct Portland Oregon 97213 This document summarizes the stormwater management system. Based on geotechnical reports, infiltration is poor and stormwater must be detained, then drained to the combined stormwater/sewer. The site plan shows the siting of the home on the lot. Based on siting, slope, downspout locations, and landscaping considerations, the plan uses two flow-through planter systems. The roof is divided among several planes each with a sq ft value as indicated within a circle (the upper value) on the site plan (the lower value represents 6% of the sq ft value for the simplified approach). One roof plane (B2) is split between the two systems. The drain routes shown on this plan are abstract, actual pipe routes will follow foundation footings. The planters follow the city’s stormwater management details for rock depth, soil depth, freeboard depth, drainage, and overflow specifications. Refer to details for calculations of planter sizing for each drain system. The planters are constructed of plywood to hold shape while filling wth rock and soil and for backfill. The top of the planters is finished with decorative block. The planters are planted with vegetation as specified in the city’s design specifications. 2 c d c b b2 B2 split drain d b e a h g f i h 1