Development increases impervious surfaces and land disturbance needed for development often affects natural drainage patterns. This leads to more stormwater runoff and localized flooding, both of which increase the amount of pollutants in the region’s waterways and water bodies. More than 86 percent of the region’s water bodies were identified as impaired by the state’s Department of Environment and Conservation in 2010. Almost 36 percent of the region’s waterways were identified as impaired or threatened in the same evaluation (however, 41 percent of the region’s waterways were not evaluated at that time).