UPDATE: (6:15 p.m.) More information just in from D.C. Water — D.C. Water Director of Public Affairs Alan Heymann tells DCist that D.C. Water crews are excavating at this moment to start the repair on the broken valve. The best guess on the water shut-off is approximately 4-6 hours; it will mostly affect businesses on the east side of 18th Street NW between Florida Avenue and Columbia Road. DDOT has opened one lane of Florida Avenue to traffic in each direction.

UPDATE: (5:15 p.m.) D.C. Water has successfully stopped the flow of water, but U Street is currently closed from 18th to 16th. Florida Avenue is closed from U to California. Use an alternate route if you’re driving in the area.

A water main break at the intersection of Florida Avenue and U Street NW near 18th Street is causing a bit of a headache for drivers who may have tried to get out of the office a little bit early this afternoon. The 1700 block of U Street has been closed to traffic due to the water.

“This was the site of a scheduled valve replacement last night, and the replacement malfunctioned,” said D.C. Water Director of Public Affairs Alan Heymann. Heymann confirmed that D.C. Water has had to shut water off in the immediate area, but details were scant so far — the agency is not sure at this moment how many residents have had their service interrupted, but crews will be working on the scene as soon as possible.

If you’re water has been turned off, you can always call the D.C. Water command center at 202-612-3400 to get an estimate on when water service will be restored.