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.
(Ord. 06-0383, passed 3-15-06)