Laserfiche WebLink
-CODE OF ORDINANCES <br /> Chapter 30- LAND DEVELOPMENT REGULATIONS <br /> ARTICLE VII. STORMWATER MANAGEMENT <br /> (Ord. No. 07-05, § 1, 6-18-2007) <br /> Sec. 30-2175. Post construction stormwater management. <br /> The purpose of this section is to comply with the state's goal of obtaining a pollutant loading water <br /> quality model that will provide, at minimum, changes in average annual flow volume, total suspended <br /> solids, and phosphorus. This modeling will be based on two time periods: from 1988 (1988-1990) to the <br /> present (2000-2005), and from the present to 2020 or ultimate development, whichever will occur first. <br /> (a) The applicant shall consider reducing the need for stormwater management performance <br /> standards by incorporating the use of natural topography and land cover. It shall also: <br /> 1. Minimize impact to significant natural features. <br /> 2. Review the site for wetlands, wooded areas of significance, rare and endangered species <br /> habitat, areas designated by the County Biological Survey (1993), and/or Elk River Natural <br /> Resource Inventory (NRI) (December 2004). These areas should not be developed. <br /> 3. Minimize impervious surface coverage to the maximum extent practicable. <br /> 4. In designated shoreland areas the development shall meet the impervious surface <br /> requirements of the shoreland ordinance regardless of conveyance systems. <br /> 5. Have a proposed design, suggested location and phased implementation of effective, <br /> practicable storm water management measures for plans designed, engineered and <br /> implemented to achieve the following results: <br /> a. Volume control. Designer shall be required to provide soil boring analysis to determine <br /> the infiltration rate prior to approval of plans. <br /> b. Phosphorus control. Stormwater shall be treated to remove 60 percent of the post- <br /> development phosphorus load on an annual basis before discharge to natural water <br /> bodies. Where water quality ponding is exclusively used to meet the phosphorus <br /> removal requirement, the ponds must be sized to store the site runoff from a two and <br /> one-half inch rainfall below the normal outlet elevation. <br /> c. Total suspended solids. Treatment also must achieve a 60 percent removal of <br /> suspended solids. <br /> d. Oil and grease control. For all storm water plans for commercial or industrial <br /> developments and all other uses where the potential for pollution by oil or grease, or <br /> both, exists, the first one-half inch of runoff will be treated using the best oil and <br /> grease removal technology available. This requirement may be waived by the city <br /> when the applicant can demonstrate that installation of such practices is not <br /> necessary. <br /> e. Runoff rate control. Refer to city's design standards. <br /> (b) All stormwater facilities shall be designed, installed and maintained to effectively accomplish the <br /> following: <br /> 1. Minimize predevelopment peak runoff rates for the two year, 24 hour storm event. <br /> 2. Minimize predevelopment peak runoff rates for the ten year, 24 hour storm event. At a <br /> minimum, the storm sewer system shall be designed for this storm event. Low areas must <br /> have an acceptable overland drainage route with the proper transfer capacity when the <br /> event is exceeded. <br /> 3. Minimize predevelopment peak runoff rates for the 100-year, 24-hour storm event. <br /> Elk River, Minnesota, Code of Ordinances Page 9 <br />