(A) It is recognized that some streams, drainage channels, culverts, and CSO serving the city do not have sufficient capacity to receive and convey stormwater runoff resulting from continued urbanization. Accordingly, the storage and controlled release of excess stormwater runoff as well as compensation for loss of floodplain storage shall be required for all developments and redevelopments (as defined in § 52.005) located within the city. Release rate requirements, downstream restriction considerations, acceptable outlet, and adjoining property impact considerations rates are detailed in the City of Washington Stormwater Technical Standards.
(B) Due to unknowns regarding the future development patterns and the associated proposed stormwater quantity management systems within a watershed, it is the policy of the city to discourage direct release of runoff from a new development or redevelopment without providing detention. However, in rare circumstances, where a comprehensive watershedwide hydrologic study or watershed plan of a major stream (not a “beat the peak” analysis) adopted by the city substantiates the benefits of (or allows for) direct release for a proposed development located adjacent to a major stream, the detention requirements set in this chapter may be waived. Other special circumstances when such a waiver may be considered by the city include situations where the design of a regional pond has already taken into account the provision of direct release in certain areas in the watershed.
(C) The city seeks to promote responsible development that effectively addresses both the quality and quantity of stormwater, integrates green infrastructure, and minimizes the adverse effects of stormwater runoff resulting from development and expanded impervious surfaces.
(Ord. 10-2024, passed 7-8-2024)