Best Management Practices (BMPs) are structural and non-structural measures, techniques, and strategies used to prevent, reduce, or manage the quantity and quality of stormwater runoff in order to protect receiving waters, infrastructure, and surrounding environments.
In stormwater management, BMPs encompass a wide range of practices designed to address the impacts of development and land use on hydrology and water quality. They are intended to control runoff volume, peak discharge rates, pollutant loading, and in some cases promote groundwater recharge and ecological function. BMPs are a core component of regulatory programs such as municipal separate storm sewer system permitting under the United States Environmental Protection Agency, where municipalities are required to implement them to meet water quality standards.
BMPs are broadly categorized into two main types. Structural BMPs are physical systems or constructed features that treat or manage stormwater. Examples include detention basins, infiltration basins, bioretention areas, constructed wetlands, sand filters, and permeable pavement systems. These practices are engineered to store, filter, infiltrate, or otherwise treat runoff before it is discharged.
Non-structural BMPs, on the other hand, focus on policies, procedures, and behavioral practices that reduce stormwater impacts at the source. These include public education programs, erosion and sediment control during construction, illicit discharge detection and elimination, street sweeping, proper material storage, and land use planning strategies that minimize impervious cover.
BMPs are often selected and designed based on site-specific conditions such as soil type, drainage area, land use, and regulatory requirements. Increasingly, modern stormwater management emphasizes the use of “green infrastructure” BMPs that mimic natural hydrologic processes, promoting infiltration, evapotranspiration, and decentralized control of runoff.
Maintenance is a critical aspect of BMP performance. Without regular inspection and upkeep, BMPs can lose effectiveness, become clogged, or fail entirely. As such, long-term operation and maintenance plans are typically required as part of BMP implementation.
Overall, Best Management Practices represent a comprehensive approach to managing stormwater in a way that balances development needs with environmental protection, making them a foundational concept in contemporary stormwater management.