13.80.090 Storm water and drainage improvement standards.
(1) All storm water and drainage improvements shall be planned, designed, permitted, constructed, and maintained in accordance with the requirements of the latest version of the Washington Department of Ecology Stormwater Management Manual for Eastern Washington (SWMMEW), which is hereby adopted by reference, including all amendments and modifications thereto as adopted by the Washington State Department of Ecology as authorized by RCW 35A.12.40. The Technical Requirements outlined in Appendix 1 of the Eastern Washington Phase II Municipal Storm Water Permit shall apply to all new development and redevelopment sites.
(2) All new storm water and drainage facilities shall be designed by a professional engineer licensed in the State of Washington. Complete storm water runoff and drainage facilities sizing calculations shall be submitted to the Public Works Director for review, comment, and utilization for the granting or denying of any permit.
(3) All subsurface infiltration facilities used for the treatment and disposal of storm water shall meet the requirements of and be registered with the Washington State Department of Ecology Underground Injection Control (UIC) program. The registration shall be completed prior to project acceptance, approval, and the issuance of any certificate of occupancy.
(4) Storm Runoff.
(a) Occurring on all lots or division of land subject to development by the construction of structures, improvements and the installation of impervious surfaces shall be retained and disposed of on site with no storm runoff occurring thereon permitted to enter the public right-of-way or public storm drainage system.
(b) For new public streets shall be designed and constructed in accordance with the Stormwater Management Manual to the point where the adjoining property owner’s responsibility for further extension begins.
(c) All storm water sewer designs for new public streets shall be based upon an engineering analysis that takes into account total drainage areas, runoff rates, pipe and inlet capacities, treatment capacity, and other factors pertinent to its design and operation.
(5) The property owner upon which a storm water and drainage facility is located shall maintain all storm water best management practices (BMPs) for those facilities that are installed upon private property. [Ord. 4309, 2016; Code 1970 § 13.60.120.]