55 outfalls · searchable
Find the sewage outfall nearest you
When it rains hard enough, these pipes discharge a mix of sewage and street runoff straight into the river. Most are plain concrete openings at the waterline. You have probably walked past several.
Only 15 of these pipes discharged at all in 2025, and three of them accounted for 86% of the volume. The Anacostia's outfalls are now largely dormant; the Potomac's are not.
By neighbourhood
Type a neighbourhood, street or outfall number. Figures are for 2025.
| Outfall | Neighbourhood | River | Location | 2025 volume | Discharges | Longest |
|---|
What the numbers mean
Volume is millions of gallons of combined sewage and stormwater discharged during 2025. Discharges is how many separate times that pipe ran. Longest is the single longest continuous discharge that year, in hours.
Almost all of this is modelled, not measured. DC Water meters only a handful of outfalls. For the rest it runs a computer model of what it believes happened during a storm. In 2025, 5.4 million gallons were metered and 248 million were modelled.
Source: DC Water quarterly Combined Sewer Overflow operations reports filed with the US EPA, 2005–2026. Neighbourhood labels are our own, derived from the street locations DC Water gives for each outfall. Download the raw data →