§ 55.55 DESIGN REQUIREMENTS FOR DETENTION PONDS.
   (A)   Wherever practical, ponds shall be located in natural depressions or low lands but not in protected wetlands or regulated floodplain areas. Discharge for ponds should be directed towards wetlands where applicable.
   (B)   All ponds built in the City are required to have all of the following characteristics unless specifically waived by the Director of Public Services:
      (1)   A minimum of 15-feet buffers must be maintained between adjacent property and the toe of berm for the detention pond.
      (2)   A maximum of 3:1 side slopes is required for all berms.
      (3)   The length to width ratio will be no less than 3:1 to promote adequate settling of solids.
      (4)   All inlets to the pond will produce a nonerosive velocity of storm water when discharged during peak flows. Permanent erosion control measures will be required where exit velocities exceed four feet per second.
      (5)   The crest of the berm must have a minimum width of five feet around the entire pond.
      (6)   Pond bottom slopes will be 2% if grassed or 1% if concrete or asphalt is proposed. Concrete or asphalt will be considered for hydraulic purposes only, and proprietors are encouraged to use grass or natural vegetation.
      (7)   Pond cross slopes will be as listed in subdivision (B)(7).
      (8)   Maximum depth from the elevation to the emergency spillway and the pond base elevation will be four and a half feet, although three feet is more appropriate.
      (9)   The toe of any berm may not be any closer than 15 feet from any outbuilding, and 25 feet from any building intended for occupancy.
      (10)   A method for screening the pond will be submitted for review and approval to ensure that the pond will be aesthetically pleasing to the surrounding properties.
      (11)   Water loving trees such as willows shall not be planted within 80 of the pond.
      (12)   All obstacles, such as old farm tiles, that have the potential to affect the design performance will be reported to the Director upon discovery and will be rerouted, removed, or reconfigured to the Director's satisfaction to maintain the intended design of the pond.
(Ord. 420-4-97, passed 4-21-97)