Stormwater design is the creation of a plan to collect, convey and manage rain water runoff from an area of land. Proper stormwater management plans help prevent flooding, erosion, property damage, and protect water availability. To design the stormwater management plan, O&A completes a detailed analysis of the land both before and after proposed improvements. Civil Engineers will delineate drainage basins and prepare basin maps, determine hydrologic parameters (runoff and time of concentration values), determine hydraulic parameters (pipe sizes, Manning’s coefficient, etc.), conduct necessary simulations to obtain stormwater design requirements, and produce input and output reports of final simulations. All the information obtained in the analysis phase is input into a Stormwater Management Report. The Stormwater Management Report includes, at a minimum: introduction and methodology, existing conditions discussion, proposed conditions discussion, hydrologic and hydraulic modeling discussion, and conclusions. This information is used to develop detailed construction drawings and complete necessary regulatory permit applications.