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Clean Rivers Project

Restoring Our Rivers

The Clean Rivers Project is DC Water's ongoing program to reduce combined sewer overflows (CSO's) into the District's waterways - the Anacostia and Potomac Rivers and Rock Creek. The Project is a massive infrastructure and support program designed to capture and clean wastewater during rainfalls before it ever reaches our rivers.

Protecting Our District

With the Clean Rivers Project, DC Water will protect the public from chronic sewer flooding that has plagued many areas of the District since the early 1900's. It is also cleaning up our waterways, by reducing the pollutants that enter our rivers and can be harmful to our wildlife.

What are We Building?

The Clean Rivers Project is comprised of a system of deep tunnels, sewers and diversion facilities to capture CSO's and deliver them to DC Water’s Blue Plains Advanced Wastewater Treatment Plant.  The Clean Rivers Project is also installing Green Infrastructure or "GI" to assist with the reduction of CSO's to the Potomac River and Rock Creek.  The Anacostia River and Potomac River tunnel systems include more than 18 miles of tunnels that are larger than the Metro tunnels and are constructed more than 100 feet below the ground.

Clean Rivers System for Anacostia and Potomac Rivers and Rock Creek

How Does the System Work?

With the current sewer system, practically every time it rains, untreated sewage and rainwater (combined sewage) is discharged into the District’s rivers and creeks.  The Clean Rivers project will install "diversion facilities" at strategic locations to capture this untreated sewage and divert it to the new 157 million gallon tunnel system where it will be stored and conveyed to the Blue Plains Advanced Wastewater Treatment Plant for treatment.  Each diversion facility consists of a Diversion Chamber to intercept flow from the existing sewers, an Approach Channel to direct the flow and create a vortex, a Drop Shaft to drop the flow approximately 100 feet and an Adit to connect to the main tunnel system.

The entire system works by gravity, with no moving parts to direct and capture flow.  During dry weather conditions, the existing sewer system will have the capability to deliver flow to Blue Plans for treatment through its existing Dam and Interceptor system.  The tunnel system is designed to capture "wet weather" or combined sewage only.

Typical Clean Rivers Diversion Facility (click to enlarge)

What are the Benefits?

The DC Clean Rivers Project will reduce CSOs annually by 96 percent throughout the system and by 98 percent for the Anacostia River alone.  In addition, the Project will reduce the chance of flooding in the areas it serves from approximately 50 percent to 7 percent (equivalent to a 15-year storm) in any given year and reduce nitrogen discharged to the Chesapeake Bay by approximately 1 million pounds per year.



A Drop's Life

Learn about the Clean Rivers Project from the perspective of a single water drop, in this 4-1/2-minute cartoon.