The site is divided into six (6) drainage areas, with most of the storm water directed to the south, shifting the drainage of several acres of the site from one drainage basin to a different drainage basin. The storm water system is made up of wet and dry detention basins. The site must comply with all city, state, and federal regulations related to storm water management.
A. There shall be submitted to and approved by the West Des Moines public works department a master storm water management plan for the entire development which shall govern the overall storm water management of the development.
B. A more specific, detailed storm water management plan shall be submitted to and approved by the city prior to any development on the site. The detailed storm water management plan shall be in accordance with the Des Moines metro design standards and provide detailed information regarding storm water overflow if basin overtopping was to occur. A provision to route overflow water in a manner that will not adversely affect and/or damage adjacent/downstream private properties, create life/safety issues for the public, flood public streets and/or damage public infrastructure shall also be detailed and provided. Said details shall also include a summary that describes how the water will be routed and a detail that includes swales, arrows indicating direction of flow, etc.
C. A letter from the Iowa department of natural resources (IDNR) which verifies that a dam permit is not required for the grading and development of this site as proposed shall be provided. (Ord. 1647, 9-26-2005)