The D.C. Water and Sewer Authority is investigating a leak in a pressurized 2.5-mile tunnel that carries as much as 30 millions gallons of drinking water a day from the Washington Aqueduct across Northwest Washington and through downtown.
All potable water flowing through the so-called Crosstown Water Tunnel has been rerouted to other mains as the agency gears up for a monthlong inspection of the pressurized chute, which runs from Foxhall Road to Scott Circle. The tunnel is 7 feet in diameter and ranges from 70 feet to 200 feet below ground. WASA officials say there should be no effect on water service during the investigation.
The leak, which released about a half gallon per minute, was discovered several months ago roughly just west of 25th and N streets in Rock Creek Park. A National Park Service employee found an inexplicable patch of wet ground on a dry day, and the water authority was called in to figure out why, said Duncan Mukira, WASA project manager.
WASA stopped the 10 million to 30 million gallon per day flow through the 25-year-old tunnel and the wetness disappeared, Mukira said Wednesday. Four million gallons of standing water were then pumped out of the tunnel, dechlorinated and redirected into the C&O Canal, so that work could get under way.
The authority is unclear on the full extent of damage to the tunnel. The investigation and ultimate repairs will fix a crack before it grows into a major rift, Mukira said. And there are environmental factors as well.
“Obviously you don’t want to be putting chlorinated water in Rock Creek,” he said. “You don’t want to be draining potable water into a creek that has life in it.”
Traffic will be affected during the monthlong inspection. N Street will remain closed between Corregidor and 15th streets as WASA inspectors enter the tunnel through a shaft in the street. The tunnel’s other two entry points, one at 25th and N and the other at Foxhall Road, are not in the street.
