Laserfiche WebLink
An adopted and implemented basin plan (Minimum Requirement #9) may be used to <br /> develop source control requirements that are tailored to a specific basin, however, in all <br /> circumstances, source control BMPs shall be required for all sites. <br /> (7) MINIMUM REQUIREMENT #4: RUNOFF TREATMENT BMPs <br /> All projects creating five thousand (5,000) square feet or more of net additional <br /> pavement shall provide treatment of stormwater. Treatment BMPs shall be sized to capture <br /> and treat the water quality design storm, defined as the 6-month, 24-hour return period <br /> storm. The first priority for treatment shall be to infiltrate as much as possible of the water <br /> quality design storm, only if site conditions are appropriate and ground water quality will not <br /> be impaired. Direct discharge of untreated stormwater to ground water is prohibited. All <br /> treatment BMPs shall be selected, designed, and maintained according to the City of <br /> Everett's Stormwater Management Manual. <br /> Stormwater treatment BMPs shall not be built within Environmentally Sensitive <br /> Areas or their required buffers (except as allowed in the City's Zoning Code), except for <br /> necessary conveyance systems as approved by the City. <br /> (8) MINIMUM REQUIREMENT #5: STREAMBANK EROSION CONTROL <br /> This requirement applies when five thousand (5,000) square feet or more of <br /> impervious surface is added or created by a project and stormwater runoff is discharged <br /> directly or indirectly to a stream: <br /> Streambank erosion shall be controlled by limiting the peak rate of runoff from <br /> individual development sites to fifty (50) percent of the existing condition 2-year, 24-hour <br /> design storm for the developed runoff rate from the 2 year, 24-hour storm, while maintaining <br /> the existing condition peak runoff rate for the 10-year, 24-hour and 100-year, 24-hour <br /> design storms. As the first priority, streambank erosion control BMPs shall utilize <br /> infiltration to the fullest extent practicable, only if site conditions are appropriate and ground <br /> water quality is protected. Streambank erosion control BMPs shall be selected, designed, <br /> and maintained according to the City of Everett's Stormwater Management Manual. <br /> C STAGORD:STORM ORD(LM9/27/96) <br /> 13 <br />