DC's $819M Potomac River Tunnel breaks ground with dual TBMs DC Water breaks ground on a 5.5-mile tunnel under D.C. to capture sewage overflows, aiming to cut Potomac River pollution by 93% by 2030.

Waterways around DC will be closed during June 14 military parade The preliminary plan is to block off access to the Potomac River from Hains Point to the Key Bridge, News4 has learned.