If increased flooding frequency and magnitude is not desired, building and land use practices that do not maximize the frequency and magnitude of flood events should be considered.
Increasing the amount of surface area in a watershed that is impervious decreases water infiltration into the aquifer and increases surface water runoff quantity and rate. The consequences are increased drought risks during years with less rainfall and much more frequent and greater magnitude flood events which include flooding of areas that were previously believed not to be at risk. Land and building practices that decrease the volume and rate of surface water runoff should be considered when increasing flooding frequency and severity is undesirable. Green roofs are a method for decreasing the magnitude and rate of roof water runoff while also generally decreasing building air conditioning needs. Pervious sidewalks, driveways, parking lots, alleys, and even streets are a method for decreasing the magnitude and rate of land surface water runoff while still allowing commercial and residential development and, as an additional benefit, protecting stream water quality. Maintaining and reestablishing wetlands and other ecosystem components that prevent or slow surface water runoff is another method for decreasing the magnitude and rate of land surface water runoff which also has the additional benefit of protecting stream water quality.