Washington D.C./District of Columbia Stormwater Ordinance - 2013 Rule on Stormwater Management and Soil Erosion and Sediment Control
In 2013, the District Department of the Environment (DDOE) released an amended Rule on Stormwater Management and Soil Erosion and Sediment Control to require that major development and redevelopment projects incorporate additional measures to retain stormwater and reduce runoff. The District offers compliance flexibility by allowing for some off-site retention, the ability for developers to pay an in-lieu fee, or the option to buy stormwater retention credits. The District also developed a Stormwater Management Guidebook (SWMG) to provide technical guidance on stormwater best management practices (BMPs) and how to comply with the rule. The amended 2013 Stormwater Rule and SWMG are designed to improve water quality and reduce runoff to the Anacostia and Potomac Rivers, Rock Creek, and their tributaries. Green infrastructure practices can also help reduce risks from climate impacts by reducing urban drainage flooding and urban heat.
The rule applies to projects involving major land disturbing activities (greater than 5,000 square feet of land disturbance) and substantial improvements to structures (greater than 50 percent improvement to the value of a structure). The rule places a relatively high retention requirement (1.2 inches of rainfall for major land disturbing activities and 0.8 inches for substantial improvement projects). The rule requires the retention of stormwater volume on site with a menu of stormwater BMPs through which stormwater is absorbed by the soil, infiltrated into the ground, evapotranspired by plants, or stored for use on site.
The District is also unique because it allows for flexible pathways for compliance including allowing up to 50% retention offsite, payments-in-lieu of offsite retention, and a stormwater credit trading system. The credit trading system facilitates offsite retention and creates incentives in other parts of the city to retain more than the legally required limit because that extra retention can be sold as a credit. By building in some compliance flexibility, DC was able to put a higher retention requirement in place while recognizing the concerns of local developers.
According to DDOE, the program will improve equity in the allocation of the burden of stormwater management, and they will promote sustainable development within the District. DDOE sees the off-site provisions in these amendments as having the potential to result in a relatively large amount of retention BMPs being installed in less affluent parts of the District, meaning that these amendments also have the potential to improve environmental justice outcomes in the District. According to the DDOE, these amendments more equitably allocate the costs of stormwater management by requiring properties undergoing major development or redevelopment to do more to reduce the stormwater runoff from their property. The idea that these costs should be reflected in the costs of developing properties is in keeping with the established principle of environmental policy and economics that external environmental costs should be internalized into the costs of a transaction. By making the shift to the retention-based approach in these amendments, regulated development will become a major driver behind the long-term effort to retrofit impervious surfaces in the District and, ultimately, to restore health to the District’s waterbodies.
DDOE has also designed these amendments to work in concert with other sustainability initiatives in the District, including the Office of Planning’s development of Green Area Ratio requirements under the zoning code and Mayor Gray’s Sustainable DC Plan.
Publication Date: 2013
- District Department of Energy and the Environment (DDOE) - Washington DC
- Green Infrastructure Toolkit > Scaling Up: Integrating Green Infrastructure into Existing Processes > Regulatory Tools
- Water quality
- Precipitation changes