§ 153.093  STORMWATER MANAGEMENT; REQUIRED FACILITIES.
   (A)   Purpose and intent.
      (1)   The purpose of this section is to designate stormwater requirements and criteria for land disturbance activities. It is intended to prevent and control damage such as sedimentation, flooding, water pollution, and degradation of aquatic habitat caused by soil erosion and uncontrolled stormwater runoff. These stormwater requirements are intended to promote the health, safety, welfare, and natural resources of the village.
      (2)   The village has completed a comprehensive regional stormwater management plan that includes current village boundaries as well as tributary, extraterritorial areas. It is the intent of the village that this plan be followed as land development activities occur. However, in situations where the plan is not applicable or unique circumstances exist, as determined by the Village Board, stormwater management requirements contained in this section will govern.
   (B)   Applicability. This section shall apply to all land development in the village and lands subject to extraterritorial land division review.
   (C)   Design criteria and standards. Any land disturbance activity subject to the provisions of this chapter or Chapter 152 shall comply with the criteria and standards set forth in the village’s Stormwater Management Plan and the following standards.
      (1)   Storm sewers.
         (a)   Storm sewers shall be installed where it has been determined by the Village Engineer that grassed swales are not appropriate because of physical incompatibilities or aesthetic reasons.
         (b)   Storm sewers shall be designed to accommodate the ten-year recurrence interval storm, except arterial streets, where they shall be designed to accommodate the 50-year recurrence interval storm.
         (c)   Storm sewer and ancillary facilities shall be constructed in accordance with the latest edition of Standard Specifications for Sewer and Water Construction in Wisconsin.
      (2)   100-year flood protection.
         (a)   The lowest building opening shall be set at least two feet above the 100-year high water level of ponds and floodplain elevations.
         (b)   Overflow routes shall be established to provide relief during storm events that exceed design conditions.
         (c)   Open channels shall be designed to convey the flows from the 100-year recurrence storm event.
      (3)   Pond water quantity. Where the Village Engineer determines that water quantity concerns govern the proposed land disturbance, on-site management techniques shall be used to meet the following minimum performance standards:
         (a)   Reduce the peak 100-year developed flow of the entire development down to the two-year presettlement flow. This requirement may be reduced or increased if the Village Board, upon the recommendation of the Village Engineer, determines that downstream conditions warrant; and
         (b)   Velocities shall be non-erosive to discharge locations, outfall channels, and receiving streams.
      (4)   Pond water quality.
         (a)   Where the Village Engineer determines that water quality concerns govern the proposed land disturbance, on-site management techniques shall be used to meet the following minimum performance standards:
            1.   Remove 80% of the total suspended solids. To achieve this level of control, stormwater practices shall be designed to accommodate, at a minimum, the runoff volume resulting from a one and one-half inch, four-hour rainfall; and
            2.   Stormwater discharge shall be pretreated prior to release to wetlands at rates that will not be disturbing to vegetative habitat. Significant degradation of wetland functional values due to stormwater pollutants shall be avoided.
         (b)   Complete water quality calculations shall be submitted.
      (5)   Additional pond requirements. Ponds and infiltration devices shall not be located closer to water supply wells than indicated below without the approval of the Village Board:
         (a)   One hundred feet from a private water supply well; or
         (b)   A flat access area for maintenance and clean-out shall be provided.
   (D)   Stormwater management report. A stormwater management report shall be submitted to the Village Engineer for all land disturbing activities. Approval of the stormwater management plan by the Village Engineer shall be obtained prior to any land disturbance activity. This plan shall include the following items:
      (1)   Existing two-foot contour site topography (U.S.G.S. datum) and features such as wetlands, floodplains, woodlands, and the like. Enough of the contiguous property shall be included to show sub-basins and watercourses that may affect the proposed development;
      (2)   Proposed two-foot contour site topography (U.S.G.S. datum), including proposed improvements that include stormwater conveyance systems, drainage easements, stormwater management facilities, outlet details, and other pertinent features;
      (3)   Detailed planting plan indicating planting materials above and below the normal water level;
      (4)   Details, cross-sections, and profiles;
      (5)   Hydraulic/hydrologic calculations of the two-year, ten-year, and 100-year recurrence storm and adequate study of downstream capacity conditions. This work shall include assumptions, backup data, and maps;
      (6)   Copies of review letters and permits from state and federal agencies; and
      (7)   Additional items deemed necessary by the Village Engineer to ensure compliance with this section.
   (E)   Required stormwater facilities benefitting other lands. The property owner shall be required to construct and pay the cost of all required on-site stormwater facilities. However, in the event that on- or off-site facilities that also benefit other land are required, the village may construct such facilities and levy a special assessment upon the benefitting properties in proportion to the benefit derived.
   (F)   Dedication of stormwater facilities. The property owners shall dedicate all easements to stormwater facilities to the village in accordance with § 153.009, including access to ponds from a public street.
   (G)   Construction certification. The developer shall provide the Village Engineer with certification management facilities. This certification shall consist of two surveys. The first survey is required when the village conditionally accepts the improvements, at which time the building permits may be issued. The second survey shall be submitted to the Village Engineer prior to final acceptance of the stormwater facilities. These surveys shall establish the as-built conditions of the stormwater management facilities, including storage and wet volume presented in the pond.
   (H)   Maintenance of stormwater facilities. The village shall maintain all stormwater facilities located in public rights-of-way and ponds serving off-site properties. The property owner shall maintain all on-site stormwater facilities, including on-site ponds. In the event the property owner fails to properly maintain such facilities, the village shall provide necessary maintenance, the cost of which shall be charged to the property owner and, if not paid, shall be extended on the current or next tax roll pursuant to Wis. Stats. § 66.0627.
   (I)   Enforcement. The Village Engineer is authorized to administer and enforce compliance with this chapter. The Engineer shall have the following powers and duties:
      (1)   Advise the applicant of the requirements of this chapter and assist them with administrative procedures;
      (2)   Review applications, issue permits, and make all determinations stated in this section;
      (3)   Conduct inspections of the work and investigate complaints related to this section; and
      (4)   Carry out long term duties relating to ensuring the long-term maintenance of the stormwater management facilities such as site inspections and make recommendations for needed repairs or maintenance.
   (J)   Appeals. Any person aggrieved by any order or determination made by the Village Engineer may appeal such order or determination by the Village Board for final determination at the next Village Board meeting.
(Prior Code, § 18.09)  (Ord. 8-97, passed 6-10-1997; Ord. 2-98, passed 2-26-1998)