High water in the Potomac River is prompting closures in the Chesapeake and Ohio Canal National Historical Park.
A low-pressure system has hovered over the area for several days, now, bringing daily scattered showers and storms and, at times, heavy downpours. People in flood-prone areas are on alert for flooding.
While the low-pressure system is starting to let up, the Potomac is expected to reach its highest point in the next 24 hours or so, NBC Washington meteorologist Doug Kammerer said.
Section A of the Billy Goat Trail and the Olmsted Island bridges in the Great Falls area are closed, park managers said. The Spring Gap and Paw Paw campgrounds also are closed.
High water covers the canal towpath near Whites Ferry, Edwards Ferry and Harpers Ferry, and at Dam 4 in Washington County, officials said.
Several park roads are also closed, and officials said all hiker-biker campsites and boat ramps should be avoided.
Managers said high water is expected through the weekend, and park users are urged to stay a safe distance from the river.