The plans and specifications of every drainage and storm sewer system shall include provisions to show compliance with the drainage laws of the State and any subdivision thereof in effect at that time, provided, however, that by requiring that the Subdivider/Developer evidence planned compliance with drainage laws, the Village assumes no responsibility to landowners or others for damage caused by noncompliance with such laws.
(A) Properly sized storm sewers shall be provided to carry surface runoff from streets and curb and/or gutters and shall be of sufficient length that they transport the runoff at least sixty (60) feet from the street pavement and into existing natural drainageways or swales and approved drainage facilities.
(B) Natural drainage swales may be utilized to accommodate surface runoff providing they are located near lot lines and the flows induced therein do not pose a health or safety hazard for residents or occupants.
(1) In general, all drainage swales having less than one percent (1%) slope shall be paved with Portland Cement Concrete or shall utilize storm sewers to transport storm water flows. Ditches over two (2) feet deep from grade to flow line shall utilize storm sewer to carry storm water flows.
(C) Drainage facilities shall be adequate to accommodate potential runoff from the entire drainage area upstream of the proposed subdivision.
(1) Potential runoff shall be determined on the basis of maximum land use of the upstream area that is consistent with current zoning or adjacent land use trends.
(D) In order to protect downstream property from potential damages by increased flows or greater velocities, and where such facilities are deemed necessary in the interest of public safety and welfare, the Village shall require the Subdivider/Developer to install drainage detention or retention facilities.
(1) Drainage detention facilities shall be designed to accommodate the excess runoff, due to the proposed development, from the one-hundred- year design storm.