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, and the Stormwater Management Guidebook (SWMG) which provides technical guidance on how to comply with the rule.
The rule requires the retention of stormwater volume on site with a menu of stormwater management practices through which stormwater is absorbed by the soil, infiltrated into the ground, evapotranspired by plants, or stored for use on site. The amended 2013 Stormwater Rule and SWMG are designed to provide greater protection for the Anacostia and Potomac Rivers, Rock Creek, and their tributaries. According to the DDOE, they will improve equity in the allocation of the burden of stormwater management, and they will promote sustainable development within the District.
The District’s stormwater ordinance has a relatively high retention requirement (1.2 inches of rainfall). The District has also created 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.
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
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