Dating back to the 1800's, Alexandria's legacy combined sewer system was designed to overflow to nearby waterways on rainy days. RiverRenew, the largest infrastructure project in Alexandria's history, was implemented to solve this issue and ultimately improve the health of the Potomac River. 

The Pendleton Street Diversion Facility is a critical component of the project that was engineered to capture and convey combined sewer flows into the Waterfront Tunnel. Once in they arrive in the tunnel, these flows will make their way by gravity to AlexRenew for treatment. When the RiverRenew project is complete in 2026, the new diversion facility will reduce combined sewer overflow events from 70 to less than 4 each year. 

AlexRenew began construction of the diversion facility in 2018, completing it in 2025 with the unveiling of the new Riverfront Promenade

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The promenade itself was designed to make the most of the area above the diversion facility, providing an important community space that allows visitors to better connect with Alexandria's Waterfront. But make no mistake, the diversion chamber below the surface plays a critical role in protecting the Potomac River and delivering healthier waterways for the region. Take a look at the graphic below to see how the new structure is working to protect our waterways.

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