9801 19TH AVE SE 2018-01-02 MF Import

� �_ � 1.2 PRELINIINARY �'�NDITIONS SiJNIMARY: Fresently, the s�te drains ir, a sheet flow manner from �*•�st to east. There is a low area at the southeastern comer of the site where a storm-water wet pond was installcd as a part of the master drainage plan for the site. 'T!ie overall drainage system for the site comprised of the following components: 1. Two -Net cells as follows: a. Burger King wet cell (1,283 Cubic Feet of storage): was installed. b. Les Schwab wet cell (1,058 Cubic Feet of storage): was not installed. Tlvs cell This cell 2. Water Qua1Tty Wet Pond: Tlvs pend was ir.stalled as part of the sita development plan and it was sized for the overall build-up of �n�s s�te. 3. Two Underground Detenrion pipes: They were designed to detain the 10 and 100 years storm event flows and release them at their respective pre-developed rates. They are comprised of the .','�ilowing: a. B�arger King Undergraund Detenrion pipes (270 Linear Feet of 48-inches diameter pipe): These pipes were installed as part of the restaurant construction. b. Les Schwab tJnderground Pipes (210 Lineaz Feet of 48- inches diarreter pipe): These pipes were not installed. The storm water is collected through a series of storm pipes and catch basins ( and drained into the wet pond, which provides the 2-year storage detenrion volume. The discharge from the pond is controlled to 50% of the � redeveloped rate of the 2-year storm event. Flows in excess of this will be diverted to a series of detenrion pipes, which cesigned to detai,► the 10 and 1 �0-year storm events and meter the release at the respective pre-developed Irates. The water quality treatment is provided in a two separate wet cells that will provide the treatment prior to discharge into the wet pond. Since