What is stormwater management? When it rains, a portion of that water soaks into the ground, and a portion runs off. Stormwater management is all about reducing the amount of runoff through three principles: slow it down, spread it out, and soak it in. Designers have an array of stormwater practices at their disposal to achieve these goals and integrate them into a construction project. This process is referred to as "Environmental Site Design" (ESD).
Why do we have to provide stormwater management? There are two primary reasons: First, we need to make sure that the increase in runoff generated by your house, driveway, patio, etc. does not cause flooding or erosion on downstream properties. Second, stormwater is a pollutant that contains various levels of trash, sediment, hydrocarbons, heavy metals, herbicides, and nutrients that can harm the streams, rivers and the Chesapeake Bay. From a regulatory standpoint, section 14:4 of the Queen Anne's County code requires development activity to implement stormwater management. The County Code references and relies on the Maryland Department of Environment's (MDE) "2000 Maryland Stormwater Design Manual" with subsequent revisions that describe the design, construction, and maintenance of ESD practices.