§ 160.120 STORMWATER SUBMITTAL.
   The stormwater submittal shall include narrative discussion and calculations to support a finding that the proposed development complies with the technical requirements of the permitting authorities ordinance. The submittal shall consist of, at a minimum, the following material.
   (A)   A narrative description of the existing and proposed site drainage patterns and conditions. Include description of off-site conditions, which help to identify stormwater issues considered in the design.
   (B)   A schedule for implementation of the site stormwater plan.
   (C)   On-site and off-site runoff calculations which address the following:
      (1)   Documentation of the procedures/ assumptions used to calculate hydrologic and hydraulic conditions for sizing major and minor systems;
      (2)   Cross-section data for open channels;
      (3)   Hydraulic grade line and water surface elevations under design flow conditions; and
      (4)   Hydraulic grade line and water surface elevations under base flood flow conditions.
   (D)   Site runoff storage calculations, which address the following:
      (1)   Calculation of hydraulically connected impervious area and corresponding retention volume.
      (2)   Documentation of the procedures/assumptions used to calculate hydrologic and hydraulic conditions for determining the allowable release rate.
      (3)   Documentation of the procedures/assumptions used to calculate on-site depressional storage.
      (4)   Documentation of the procedures/assumptions used to calculate hydrologic and hydraulic conditions for determining the storage volume.
      (5)   Elevation-area-storage data and calculations for site runoff storage.
      (6)   Elevation-discharge data, and calculations specifically related to the outlet control structure depicted in the plan exhibits.
      (7)   The general plan view drawing of § 160.119(B) shall indicate the areas of directly connected impervious areas and any offsetting landscaped areas as defined in § 160.034.
(Ord. 06-0383, passed 3-15-06)