2007 CEDAR ST 2023-04-10 - Laserfiche WebLink

• DESIGN AND CONSTRUCTION STANDARDS AND SPECIFICATIONS Department of Ecology for stormwater facility design in Western Washington.Modeling shall be performed using a 5-minute timestep. Additional Requirement Flow Control BMPs shall be selected, designed, and maintained in accordance with the City's adopted Stormwater Management Manual and Section 4 of the DCSS, except as noted in this Section.The Flow Control Performance Standard maybe achieved through any combination of onsite stormwater management techniques,flow control BMPs'and selective site design which can be demonstrated to achieve the standard. 6-10.1(2) . .DESIGN DOCUMENTATION Development applicants shall provide documentation of compliance with the Combined Sewer Area stormwater standards.Development applications shall include the following: • a. Stormwater Report which includes the following elements: • Narrative description-of the proposed-project, existing&proposed conditions, and proposed stormwater facilities to be implemented. • Existing and proposed site maps identifying land cover types used in the stormwater analysis • Numeric summary of existing and..proposed surface areas within the site and contributing offsite areas •.. Determination of erosion control..risks..and proposed measures to control erosion and sedimentation. • .Offsite analysis narrative description and figure describing upstream areas which contribute runoff to the site and the downstream system which will receive runoff from the site:Describe any identified-issues which-may saffectorizould•be-exacerbated by the project. • Flow control design and sizing calculations • Conveyance pipe sizing calculations • Other reports and data required to prepare the stormwater facility design b. Construction plans for proposed stormwater facilities c. Operations and maintenance manual for all proposed stormwater facilities. d. Maintenance covenant for owner conducted maintenance of all stormwater facilities. 6-10.2 COMBINED'SEWER*CONVEYANCE-SYSTEM • . 6-10.2(1) MATERIALS AND CONSTRUCTION Elements of the combined sewer system which convey only stormwater, such as catch basins and stormwater..piping.:shall.be.constructed.in accordance with the stormwater conveyance system requirements in Section 4-2. Elements,of the combined sewer system which convey only sanitary sewage, ,or,a combination of stormwater runoff and sanitary sewage,shall be designed in accordance with Section 6-7 and 6-8. • • :..SAMTARY.SEWERS.6-16