Selected by an independent panel of industry experts, ENR’s Best Projects competition evaluates entries based on how project teams overcame challenges, contributed to their communities and the construction industry, maintained strong safety performance, and delivered excellence in design and construction quality. This year, judges reviewed projects from across Virginia, Maryland, Pennsylvania, Delaware, West Virginia, and Washington, D.C.

RiverRenew, the largest infrastructure project in Alexandria’s history, included construction of a 130-foot-deep, 2.2-mile-long tunnel beneath Alexandria’s waterfront, a new six-foot-diameter sewer pipeline, two major diversion facilities, and a 12-story underground pumping station at AlexRenew’s treatment facility.

Now fully operational, RiverRenew captures and conveys combined sewage that previously overflowed into local waterways during rain events, preventing approximately 120 million gallons of pollution each year from entering the Potomac River, Hunting Creek, and Hooffs Run.

AlexRenew took ownership of the effort in 2018 and delivered one of the region’s most complex underground infrastructure projects in only 8 years — an extremely ambitious timeline for a project of this scale. Major construction began in 2020, the Waterfront Tunnel was completed in 2024, and the full system went live on July 1, 2026.

Today, RiverRenew stands as a transformational investment in Alexandria’s environmental future, helping create cleaner waterways while demonstrating the innovation, teamwork, and engineering excellence recognized by ENR’s Best Projects program.