The Preliminary Drainage Plan shall present the developer’s overall approach to moving rainfall runoff from the development to the appropriate drainage artery. The rainfall distribution, loss rates, and hydrograph parameters used in the analysis shall be presented as described in Appendix A. The Preliminary Drainage Plan must also show the Detention System (where applicable), approximate volume, approximate sizes of any ditches, and the outfall with the proposed metering method.
The developer shall prepare or have prepared a Preliminary Drainage Plan for each development, which outlines the method proposed for, and impact resulting from the moving of rainfall runoff from the developed area to a drainage artery. This plan shall be submitted to the District for review and approval to insure that adverse drainage or flooding conditions will not be created along any drainage artery or adjacent property as a result of the proposed development. The preliminary drainage plan must carry the interim seal of the engineer that prepared the plan.