Ordinance No. 20319 - Laserfiche WebLink

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15_~. Administration and enforcement of the Clean Water Act stormwater provisions occur at the state level, through National Pollutant Discharge Elimination System (NPDES) permitting requirements. Applicable jurisdictions are required to obtain an NPDES stormwater permit from the Oregon Department of Environmental Quality (DEQ), and prepare a water quality plan outlining the Best Management Practices (BMPs) to be taken over a five-year permit period for reducing stormwater pollutants to "the maximum extent practicable." 1_64. Stormwater quality improvement facilities are most efficient and effective at intercepting and removing pollutants when they are close to the source of the pollutants and treat relatively small volumes of runoff. 17_5. The Clean Water Act requires states to assess the quality of their surface waters every three years, and to list those waters which do not meet adopted water quality standards. The Willamette River and other water bodies have been listed as not meeting the standards for temperature and bacteria. This will require the development of Total Maximum Daily Loads (TMDLs) for these pollutants, and an allocation to point and non- point sources. 18_6. The listing of Spring Chinook Salmon as a threatened species in the Upper Willamette River requires the application of Endangered Species Act (ESA) provisions to the salmon's habitat in the McKenzie and Willamette Rivers. The decline in the Chinook Salmon has been attributed to such factors as destruction of habitat through channelization and revetment of river banks, non-point source pollution, alterations of natural hydrograph by increased impervious surfaces in the basin, and degradation of natural functions of riparian lands due to removal or alteration of indigenous vegetation. 19_g. There are many advantages to keeping channels open, including, at a minimum, natural biofiltration of stormwater pollutants; greater ability to attenuate effects of peak stormwater flows; retention of wetland, habitat, and open space functions; and reduced capital costs for stormwater facilities. 20~:[8. An increase in impervious surfaces, without mitigation, results in higher flows during peak storm events, less opportunity for recharging of the aquifer, and a decrease in water quality. 21~-1-9. Stormwater systems tend to be gravity-based systems that follow the slope of the land rather than political boundaries. In many cases, the natural drainageways such as streams serve as an integral part of the stormwater conveyance system. 22~g0. In general, there are no programs for stormwater maintenance outside the Eugene and Springfield city limits, except for the Lane County roads program. State law limits county road funds for stormwater projects to those located within the public fight-of-way. 23~g-1-. Filling in designated floodplain areas can increase flood elevations above the elevations predicted by Federal Emergency Management Agency (FEMA) models, because the III-G-7