1001 N BROADWAY EVCC PARKING 2018-12-03

. • • • ; � . e�� % � / :-� 6 � € 4':S& `� I � 728 134th Street SW Suite 200 `� r � � Everett,WA 98204 �� Ph:425-741-3800 Fax:425-741-3900 � � DRAINAGE DESIGN MEMORANDUM To: City of Everett From: Ding Ye Date: August 10, 2015 File No.: 21-2015-018 Project: Everett Community College, College Plaza Suite B Demo and Parking Lot Subject: Stormwater Management EXISTING CONDTION This memorandum addresses stormwater management for the proposed building demolition and parking lot expansion project at the Everett Community College East Campus. The site is located on the east side of North Broadway near the intersection of l0th St and North Broadway in the City of Everett Washington. The project is located within the area served by the City of Everett's combined sewer system. The site is approYimately 32.000 s£ Currently it is occupied by a one-story building and a small parking lot. Stormwater runoff from the building roof and parking lot are collected and discharged into the City of Everett's combined sewer system on the east side of the building. No water quality treatment or flow control is provided on site for existing runoff. PROPOSED IlVIPROVEMENTS This parking lot expansion project will demolish the existing building of 12,700 sf and the small parking lot directly to the east of the building. The site will then be regraded and paved to provide one large parking lot. Runoff from the site will be collected in a catch basin-pipe system and conveyed into the City of Everett's combined sewer system. Based on the 2010 City of Everett Stormwater Management Manual and the Public Works Director Interim Policy (Stormwater Control in combined Sewer Area) only Minimum Requirements #1 to #5 apply to the project. This project is exempt from Minimum Requirement #6—Runoff treatment and Minimum Requirement #7—Flow Control: � � �� /