(A) The subdivider shall submit a drainage plan containing the following information, to ensure that the provisions of this chapter are met. The submittal shall include sufficient information to evaluate the environmental characteristics of the property, the potential adverse impacts of the development on water resources both on-site and downstream, and the effectiveness of the proposed drainage plan in managing stormwater runoff.
(B) The materials submitted shall be as follows:
(1) Topographic map. A topographic survey of the property and areas upstream and downstream as necessary, in the opinion of the Village Engineer, to determine off-site impacts of the proposed drainage plan. Proposed contours shall be shown. Proposed spot elevations at lot corners, at building sites, along pavement centerlines, along drainage swales and at other relevant locations may be provided in lieu of proposed contours; and
(2) Drainage system. Mapping and descriptions, where relevant, of existing and proposed drainage system features of the property and immediate vicinity including:
(a) Banks and centerline of streams and channels;
(b) Shoreline of lakes, ponds, and existing or proposed stormwater detention basins;
(c) Farm drains and field tiles;
(d) Sub-watershed boundaries within the property controlled by the owner;
(e) Watershed soils classifications;
(f) The property’s location within the larger watershed and the area of all upstream watersheds;
(g) Locations, size, cross-sectional shape, and slope of stormwater conduits, storm sewers and drainage swales;
(h) Direction and velocity of stormwater flows;
(i) Delineation of upstream and downstream drainage features and watersheds which might be affected by the development;
(j) Locations, size, and shape of stormwater detention and retention facilities;
(k) Roads, streets, other paved areas, and associated stormwater inlets;
(l) Base flood elevation, and regulator floodway where identified for the property; and
(m) Basis of design for the final drainage network components, including design calculations and a summary of design assumptions utilized.
(Ord. 97-7, passed 7-1-1997, § 5.19)