(A) This subchapter establishes the stormwater management policies for future control of stormwater runoff. A combination of temporary storage and the controlled release of stormwater runoff shall generally be required for all new commercial and industrial developments, residential subdivisions, planned unit developments, and any redevelopment or other new construction.
(B) Any area proposed for development, consisting of a tract of land three or more acres in common ownership or interest and upon which phased development is proposed, shall be required to provide a combination of storage and controlled release of stormwater runoff for future development of the entire tract.
(C) Where phased development is proposed, the developer may construct, after receiving site specific approval from the Board of Trustees, one stormwater detention facility which is built larger than initially needed in order to anticipate subsequent phases of development and/or is designed to be enlarged at later dates as additional portions of the overall site are developed. Phased construction shall include implementation of sufficient and enforceable covenants upon the land to properly document the phased implementation.
(D) Where a subdivision plat or a planned unit development involves new lots which are more than three acres in size that are zoned for commercial or industrial, the developer may provide for storage and controlled release of stormwater runoff for the developed lots by sufficient and enforceable covenant upon the individual lots. The covenant shall require construction of on-site stormwater detention facilities upon each lot at the time of subsequent development of that lot.
(E) The Rational Method, USDA Soil Conservation Service (SCS) TR-55 Method, Mannings equation, or other similar recognized methods may be used to size the drainage components for any development.
(F) Illinois State Water Survey Contract Report 2019-05 Update Bulletin 70 (or other available data acceptable to the Village Engineer) shall be utilized to determine design precipitation.
(G) All design calculations must be submitted to the Village Engineer for review.
(Ord. 97-7, passed 7-1-1997, § 5.19)