High water from the weekend rainstorm appeared to be cresting Monday without posing major threats to flood-prone locations along the Potomac and Susquehanna rivers.
The partial failure of a wooden inlet lock along the C&O; Canal five miles west of Washington prompted alerts to businesses along the canal where it enters the District of Columbia.
Lock 5, at the Chesapeake and Ohio Canal National Historical Park, was designed to feed water from the Potomac into the canal, according to park spokesman Bill Spinrad. It was closed over the weekend to protect the canal from flooding.
"One of the gates has partially failed" and water was spilling in, he said. "We're looking at an area to open the towpath to let water out of the canal, into the river, if we find the inlet lock is going to fail."
The danger appeared to be ebbing, Spinrad said; water in the canal had dropped by 12 inches to 16 inches late Monday. But a 24-hour watch was posted on the gate anyway. Park authorities planned to survey the rest of the canal for damage once the water recedes. No major problems were reported.
Water levels on the Susquehanna River above the Conowingo Dam were expected to rise 6 more inches before cresting around noon today, said John Dillow, a hydrologist with the U.S. Geological Survey in Baltimore.
Dam officials opened 11 spill gates Monday. Bob Judge, spokesman for Exelon Energy Corp., the dam's owner, said no more than 12 gates would be needed over the next 24 hours. "At 12 gates, there will be no flooding downstream," he said.
Cecil County emergency managers say Maryland Route 222 along the east side of the river begins to flood when the dam opens 14 to 17 spill gates.
In Allegany County, the State Highway Administration closed a section of Maryland Route 657 between Lonaconing and the Garrett County line when ground water spilling from an abandoned mine undermined the road.
"We can't get a good assessment until the water recedes," said SHA spokesman David Buck. "The Bureau of Mines is telling us ... it could literally be a couple of days."
Ed McDonough, at the Maryland Emergency Management Agency, said 75 people were evacuated from other flood-threatened locations in Allegany County over the weekend. A shelter was opened, but no one used it. MEMA was no longer monitoring the storm.