A Comprehensive Drainage Plan, in preliminary form (or in combined preliminary and final form), and designed to handle safely the storm water runoff and to detain the increased storm water runoff must be provided. The Comprehensive Drainage Plan shall provide or be accompanied by maps or other descriptive materials indicating the feasibility of the Drainage Plan and showing the following:
a. The extent and area of each watershed affecting the design of detention facilities as shown on USGS Quadrangle Maps or other more detailed maps as required by the Department of Planning and Building after review and recommendation by the Plan Commission.
b. The preliminary layout and design of proposed storm sewers, the outfall and outlet locations and approximate elevations, the receiving stream or channel and its 100-year return period water elevation.
c. The location and design of the proposed street system, especially including depressed pavements used to convey or temporarily store overflow from the heavier rainstorms, and the outlets for such overflow.
d. The location, cross sections and profiles of existing streams and floodplains to be maintained, and new channels to be constructed.
e. The materials, elevations, waterway openings, and the basis for design of proposed culverts and bridges.
f. Existing detention ponds and basins to be maintained, enlarged, or otherwise altered and new ponds or basins to be built and the basis of their design.
g. The estimated depth and amount of storage required in the new ponds or basins.
h. The estimated location and percentage of impervious surfaces existing and expected to be constructed when the development is completed.
i. Any interim plan which is to be incorporated into the development pending completion of the development and the Final Drainage Plan.
j. Construction site pollution control plan conforming to 327 IAC 15-5-7 or 7.5, including, at a minimum:
1. Preliminary sediment and erosion control plan;
2. Location of construction entrance; and
3. Location of storm water outlet or outlets.
k. Construction site pollution control plan conforming to 327 IAC 15-13-15 including, at a minimum:
1. Preliminary location and estimated size of temporary BMPs;
2. Temporary scrap and waste material storage and ultimate disposal methods; and
3. Draft description of proposed self-monitoring program.
l. Post-construction pollution control plan conforming to 327 IAC 15-5-6.5 and 15-13-16, including, at a minimum:
1. Preliminary location and estimated size of permanent BMPs; and
2. Description of proposed maintenance program.
(Ord. No. 1708, 6-13-07)