10-1-9: APPROVAL STANDARDS:
No stormwater management plan which fails to meet the standards contained in this section shall be approved by the city engineer.
   A.   Surface Water Management Plan: See the most recent version of the city's surface water management plan. All stormwater management plans shall be consistent with it.
   B.   Site Erosion And Sediment Control: Erosion control measures specified in grading plans must meet all requirements of section 10-1-12 of this chapter.
   C.   Wetlands: Plans must meet all requirements for wetlands contained in section 10-1-11 of this chapter.
   D.   Comprehensive Wetland Management Plan: See the most recent version of the city's comprehensive wetland management plan. All stormwater management plans shall be consistent with it.
   E.   Stormwater Management Criteria For Permanent Facilities: Plans must meet all requirements for permanent facilities contained in section 10-1-13 of this chapter. See the most recent version of the city's surface water management plan. All stormwater management plans shall be consistent with it.
   F.   Design Standards: See the most recent version of the city's surface water management plan. All stormwater management plans shall be consistent with it.
   G.   Steep Slopes: No land disturbing or development activities shall be allowed on slopes of twenty five percent (25%) or more.
   H.   Retaining Walls: Retaining walls shall not be allowed in any city drainage, ponding or utility easement.
   I.   Catch Basins: Newly installed and rehabilitated catch basins shall be provided with a sump area for the collection of coarse grained material as specified by the city engineer. Such basins shall be cleaned when they are half filled with material or as resources allow.
   J.   Drain Leaders: All newly constructed and reconstructed buildings will route drain leaders to pervious areas wherein the runoff can be allowed to infiltrate. The flow rate of water exiting the leaders shall be controlled so no erosion occurs in the pervious areas.
   K.   Structures: See the most recent version of the city's surface water management plan. All stormwater management plans shall be consistent with it.
   L.   Inspection And Maintenance: All stormwater management facilities shall be designed to minimize the need of maintenance, to provide access for maintenance purposes and to be structurally sound. All stormwater management facilities shall have a plan of operation and maintenance that assures continued effective removal of pollutants carried in stormwater runoff. It shall be the responsibility of the applicant to obtain any necessary easements or other property interests to allow access to the stormwater management facilities for inspection and maintenance purposes. The city may require a developer to enter into a contract providing for access to perform maintenance and inspection to public or private stormwater management facilities.
   M.   Models/Methodologies/Computations: Hydrologic models and design methodologies used for the determination of runoff and analysis of stormwater management structures shall be approved by the city engineer. Plans, specification and computations for stormwater management facilities submitted for review shall be sealed and signed by a registered professional engineer. All computations shall appear on the plans submitted for review, unless otherwise approved by the city engineer.
   N.   Watershed Management Plans/Groundwater Management Plans: Stormwater management plans shall be consistent with adopted watershed management plans and groundwater management plans prepared in accordance with Minnesota statutes, sections 103B.231 and 103B.255, respectively, and as approved by the Minnesota board of water and soil resources in accordance with state law.
   O.   Easements:
      1.   If a stormwater 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.
      2.   Easements are required for all ponding areas to the basin's 100-year storm high water level elevation.
      3.   Easements are required for all outlet swales and ditches, and for overland overflow routes located downstream of basins located on site.
      4.   If the storm sewer is to be installed less than ten feet (10') deep within private property, the easement shall be a minimum of twenty feet (20') wide. If the storm sewer is ten feet (10') or greater, the easement shall be twice as wide as the depth.
      5.   Easements necessary for maintenance vehicle access are required for all of the above where not directly available on a public road. (Ord. 2015-01, 2-17-2015)