(A) Approval standards. No surface (stormwater) water management plan which fails to meet the standards contained in this section shall be approved by the City Council.
(B) Site dewatering. Water pumped from the site shall be treated by temporary sedimentation basins, grit chambers, sand filters, up flow chambers, hydro-cyclones, swirl concentrators, or other appropriate controls as appropriate. Water may not be discharged in a manner that causes erosion or flooding of the site or receiving channels or a wetland.
(C) Waste and material disposal. All waste and unused building materials, including, but not limited to, garbage, cleaning wastes, debris, wastewater, toxic materials, or hazardous materials, shall be properly disposed of off-site and not allowed to be carried by runoff into a receiving channel or surface (stormwater) sewer system.
(D) Tracking. Each site shall prevent sediment from being tracked onto public or private roadways.
(E) Drain inlet protection. All surface (stormwater) drain inlets shall be protected during construction until control measures are in place with a straw bale, silt fence, or equivalent barrier meeting accepted design criteria, standards, and specifications contained in the State Pollution Control Agency publication entitled Protecting Water Quality in Urban Areas.
(F) Site erosion control. The following criteria apply only to construction activities that result in runoff leaving the site.
(1) Channeled runoff from adjacent areas passing through the site shall be diverted around disturbed areas, if practical. Diverted runoff shall be conveyed in a manner that will not erode the conveyance and receiving channels.
(2) All activities on the site shall be conducted in a logical sequence to minimize the area of bare soil exposed at any one time.
(G) Surface water (stormwater) management criteria for permanent facilities.
(1) An applicant shall install or construct, on or for the proposed land disturbing or development activity, all surface (stormwater) water management facilities necessary to manage increased runoff so that the two-year, ten-year, and 100-year storm peak discharge rates existing before the proposed development shall not be increased, and accelerated channel erosion will not occur as a result of the proposed land disturbing or development activity. An applicant may also make an in-kind or monetary contribution to the development and maintenance of community surface (stormwater) water management facilities designed to serve multiple land disturbing and development activities undertaken by one or more persons, including the applicant.
(2) The applicant shall give consideration to reducing the need for surface (stormwater) water management facilities by incorporating the use of natural topography and land cover such as wetlands, ponds, natural swales, and depressions as they exist before development.
(3) The following surface (stormwater) water management practices shall be investigated in developing a surface (stormwater) water management plan:
(a) Natural infiltration of precipitation on-site, if located outside of areas considered sensitive to groundwater contamination;
(b) Flow attenuation by use of open vegetated swales and natural depressions;
(c) Surface (stormwater) water retention facilities; and
(d) Surface (stormwater) water detention facilities.
(4) A combination of successive practices may be used to achieve the applicable minimum control requirements specified in § 150.040. The applicant shall provide justification for the method selected.
(H) Design standards. Surface (stormwater) water detention facilities constructed in the city shall be designed according to standards approved by the City Engineer.
(I) Wetlands. Rules and regulations applicable to wetlands and set forth by the State Wetland Conservation Act, Ch. 354, 1991 Minn. Laws 2794 and Federal Clean Water Act, being 33 USC §§ 1251 et seq. are hereby incorporated.
(J) Watershed management and groundwater management plans. Surface (stormwater) water management plans shall be consistent with adopted watershed management plans and groundwater management plans prepared in accordance with M.S. §§ 103B.231 and 103B.255, as they may be amended from time to time, respectively, and as approved by the State Board of Water and Soil Resources in accordance with state law.
(K) Easements. If a surface (stormwater) water management plan involves direction of some or all runoff off of the site, it shall be the responsibility of the applicant to obtain from adjacent property owners any necessary easements or other property interests concerning flowage of water.
(Prior Code, § 513.060) (Ord. passed 10-8-2003)