Best Management Practices (BMPs) are broadly defined by the South Carolina Department of Health and Environmental Control as stormwater management and conservation practices that have been demonstrated to effectively control movement of pollutants, prevent degradation of soil and water resources, and that are compatible with the land use. Simply put, BMPs help us manage and lessen the adverse impacts typically associated with stormwater runoff. BMPs can be divided into two categories: structural and nonstructural.
Structural BMPs can be thought of as engineering solutions to stormwater management. Structural BMPs are used to treat stormwater at the point of generation, the point of discharge, or at any point along the stormwater "treatment train." Structural BMPs can serve many different functions based on their design. Some structural BMPs are designed particularly for urban areas, whereas others may be designed for agriculture, forestry, or mining areas. Common examples of structural BMPs usually found within urban areas include stormwater ponds and open channels (swales).
Nonstructural BMPs are just that - nonstructural. There are no physical structures associated with these types of BMPs. Nonstructural BMPs are designed to limit the amount of pollutants available in the environment that would potentially end up in stormwater runoff. Nonstructural BMPs typically lessen the need for the more costly structural BMPs. Nonstructural BMPs can be achieved through such things as education, management and development practices. Some examples include ordinances and practices associated with land use and comprehensive site planning.
Low Impact Development (LID) is an innovative stormwater management approach with a basic principle that is modeled after nature. LID's goal is to mimic a site's predevelopment hydrology by using design techniques that infiltrate, filter, store, evaporate, and detain runoff close to its source. Examples of LID include vegetated buffers, swales, and permeable pavers.
Techniques are based on the premise that stormwater management should not be seen as stormwater disposal. Instead of conveying and managing stormwater in large, costly end-of-pipe facilities located at the bottom of drainage areas, LID addresses stormwater through small, cost-effective landscape features located at the lot level.
LID allows for greater development potential with less environmental impacts through the use of smarter designs and advanced technologies that achieve a better balance between conservation, growth, ecosystem protection, and public health. LID has numerous benefits and advantages over conventional stormwater management approaches. In short, it is a more environmentally sound technology and a more economically sustainable approach to addressing the adverse impacts of urbanization. By managing runoff close to its source though intelligent site design, LID can enhance the local environment, protect public health, and improve community livability - all while saving developers and local governments money.