National Park Service officials and volunteer crews near the nation’s capital have their hands full these days, cleaning up after a flood.

In mid-March, heavy rains and melt from the winter’s record-breaking snowstorms combined to spill the Potomac River over its banks. While still considered a moderate flood, these waters were the highest the area had seen since 1996, said Brian Carlstrom, deputy supervisor at Maryland’s Chesapeake and Ohio Canal National Historical Park.

“The thing about flooding on the Potomac is that it’s guaranteed,” said Bill Justice, acting site manager at Great Falls Park in McLean, Virginia. “It happens about every 11 years, so we were due.”

Where the River Flowed

At the C&O Canal several campgrounds, boat ramps, and the popular Billy Goat Trail near Great Falls all were temporarily closed by the flooding. The Great Falls Tavern also was turned into an island amid the flooding.

The resulting damage to the canal's towpath means the mule-drawn canal boat rides in Georgetown and Great Falls will be delayed this year, until May 1.

One scare happened at the height of the flood when waters punched through half of Lock 5, a few miles upstream from Washington, D.C. Quick-moving, muddy waters filled the canal, and park officials issued a hasty warning to businesses in Georgetown to prepare their buildings for flooding should the second half of the lock give way. Officials also closed the towpath through Georgetown. Luckily, the remaining section of the lock held, and repairs to the broken part were to start this week.

The most flooding along the canal occurred there, in D.C.’s Palisades area, and near Harpers Ferry, West Virginia, where the waters breached the towpath in two places.

The towpath is now open, but in places is narrower than usual, muddy and rocky, and festooned with root balls. Where the Potomac River poured into the canal, it eroded the towpath on the river side. Where the canal chased back into the river, it chewed away at the opposite side of the path. Everywhere the floodwaters flowed, they scoured the towpath’s surface.

“The towpath is passable, but I wouldn’t recommend doing it on a road bike right now,” Mr. Carlstrom said.

A similar story is being told at Great Falls. That park is especially ripe for flooding because the river narrows dramatically just below the falls, at Mather Gorge, creating a natural chokepoint.

All but two trails at Great Falls are now open, but damage to the Fisherman’s Eddy area is severe. The high water carried some trees down the river and knocked down others that were still standing. Many collected in that elbow of the river. Now they are blocking access for kayakers, boaters, and fishers, and the park will be calling in the big guns -- contractors specially trained in technical log removal. (See Great Falls 2010 flood photos.)

Mud, rocks, and general flood debris are decorating Great Falls trails as well. “At 11 feet, the water covers most of the trails,” said Mr. Justice. “This flood crested at 13 feet, and there was a good bit of churning away at the trails,” leaving a rough surface and downed trees.

Other area parks, such as Theodore Roosevelt Island, the Mt. Vernon Trail, and the Potomac Heritage Trail remain partly strewn with debris and river muck, but likewise are mostly open and passable.

If you come to visit, please respect the closures – for your own safety, said Mr. Justice. Some trails are closed because of fallen or hanging trees, others because waters have eaten away at the land.

Cleaning Up

Cleanup is a slow process. Both Mr. Carlstrom and Mr. Justice predict it might be summer before all the damage is repaired.

On the plus side, the flood has given the Chesapeake and Ohio Canal park extra opportunities to use its new road-paving equipment, which will allow employees not only to lay gravel, but also to better control its thickness and crowning. This equipment is intended to improve drainage of the surface and enhance sustainability, Mr. Carlstrom said.

At Great Falls, they’ll be looking to volunteers to help pick up the many pieces washed down by the floodwaters. The same park staff charged with cleaning up after the flood is also needed for other tasks, such as repairing potholes along the George Washington Parkway brought on by the winter snows. “That’s why getting volunteers out here to Great Falls to help us is so important,” said Mr. Justice.

If you’d like to help, call the park at (703) 285-2965 and ask for Aaron Larocca, who will gladly match you with a volunteer opportunity – and a chance to get good and dirty while cleaning up.