Tag Archives: Retrofitting


New Washington, D.C. Rule for Stormwater Credit Trading


The newest water trading scheme in the United States is now in place with the final passage of the Washington, D.C. stormwater trading rule.  The rule, finalized on July 22, 2013, sets up a stormwater-trading-credit program.  The new rule applies to large construction projects that disturb 5,000 square feet or more of oil, as well as renovations to structures larger than 5,000 square feet which projects costs at least 50% of the pre-project value of the structure.

In order to meet the requirements of the stormwater retention rule, property owners must meet at least one-half of the required retention volume on-site, through installation of an approved type of green infrastructure, such as a green roof, rain garden, or permeable pavement.  In addition, property owners can purchase Stormwater Retention Credits (SRCs) to meet the remaining 50% of their required retention volume off-site.  Facilities also have the option to pay an in-lieu fee of $3.50/year/gallon of Off-Site Retention Volume (OSRv).

Pervious driveway, one of the approved green infrastructure designs for SRCs.

The Stormwater Credit Exchange (SCE) is the home of the market for the stormwater credits.  It’s too early in the process to tell how much activity the SCE will see – or how much eachSRC will end up costing.  The minimum rate set is $1/SRC, but will fluctuate as the market demands.

One hope of the new rule is that encouraging the production of SRCs in order to earn money will encourage smaller retrofits across the DC area – from individual homeowners to small businesses that can easily include a retrofit, but are not required to.  Spreading the installation of green infrastructure across the District should increase overall stormwater retention and protect watersheds and water bodies that have not benefited from previous stormwater management rules.

For more information about the new stormwater rule, see The Examiner’s article on the rule.

The Stormwater Credit Exchange, operated by the Center for Environment, Commerce & Energy, contains information about the qualifications for SRCs, the trading platform, and the formulas used to calculate the retention requirements for facilities.