Washington, D.C.'s stormwater credit market lets developers buy tradeable credits from landowners who install green infrastructure, meeting part of their runoff-retention rules while avoiding costly grey infrastructure.
1.7 million+ credits (gallons of retention/year)
Credits sold since launch (2013-2024)
1.7 million+ USD
Total value of credits sold (2013-2024)
40 million+ gallons/year
Stormwater runoff captured and treated annually (as of 2024)
26 sellers
Registered credit sellers (2024)
0.42 to 2.03 USD/credit
DOEE purchase price range (2024)
Details
Maturity
Established
Promoter
DC Department of Energy & Environment (DOEE)
Period
2013-present
Keywords
stormwater management, green infrastructure, environmental markets, urban water
Context
Washington, D.C.'s Department of Energy & Environment (DOEE) launched the Stormwater Retention Credit (SRC) Trading Program in 2013, the first market of its kind in the United States.
Objectives
Property owners who voluntarily install green infrastructure (rain gardens, green roofs, permeable pavement) that retains stormwater beyond regulatory requirements can have DOEE certify and issue tradeable SRCs, each equal to one gallon of retention capacity for one year, which developers can buy to meet on-site retention requirements they cannot otherwise fully meet.
Activities
Developers purchase SRCs on the open market or through DOEE's Stormwater Retention Credit Price Lock Program, avoiding the cost of building additional grey stormwater infrastructure. The first voluntary credit-generating project was a set of rain gardens at Mount Olivet Cemetery, developed by the Catholic Archdiocese of Washington with The Nature Conservancy.
Results
By the programme's ten-year mark in 2024, more than 1.7 million credits had been sold -- through private trades and DOEE's Purchase Agreement Program -- worth over $1.7 million and representing more than 40 million gallons of stormwater runoff captured and treated annually. As of 2024 the credit registry listed 26 individual sellers, with DOEE purchase prices ranging from $0.42 to $2.03 per credit.
Conclusions
The programme depends on continued regulatory demand for credits and on DOEE's certification/verification capacity; credit prices have fluctuated over the decade as supply and demand shifted, transferring market risk onto both buyers and green-infrastructure sellers.
Implementation
Indicative cost
Medium (€50k–€500k) — No total public administrative budget is stated; the market's own trading value (over $1.7 million across 10 years) is private-sector transaction value, not government programme cost. Conservatively estimated as 'medium' (agency certification/registry administration), noted as inferred, not stated.
Time to results
Long (> 3 years) — Running continuously since 2013, past its ten-year anniversary in 2024.
Staffing & skills
DC Department of Energy & Environment (DOEE) -- certification, verification and registry administration
Conditions for success
Regulatory retention requirements on new development create durable demand for credits
DOEE Price Lock Program reduces market-price risk for buyers
Clear 1-credit-per-gallon-per-year unit definition simplifies trading
Common failure modes
Programme depends on continued regulatory demand persisting
Credit prices have fluctuated with supply/demand shifts, transferring market risk to both sides
No independent evaluation of the market against a non-market counterfactual
Where it fits
Governance type
municipal/city government regulatory agency
Scale
city-wide market mechanism
Income level
high-income
Do you run this practice?
Claim it —
verified implementers get a public contact pathway and can propose corrections.
Data sources
Where this practice's information was retrieved from, and when.
