Every two weeks, Christine DeMorro heads out to the back yard to mow the lake.

It takes six hours on a riding mower to slog through the fast-growing weeds rising from the part of her Prince William County property, as big as a football field, that used to be underwater.

Since the Lake Jackson Dam was opened in May 2012 because of concerns about leaks after an earthquake struck the area a year earlier, the water level has gone so low that neighbors now call it Creek Jackson. A new island is rising in the brown, Willy Wonka-ish water that is left. Their beach is long gone. And docks lie marooned in the midst of fields.

The good news, said Marty Nohe, a county supervisor, is that the commonwealth and the county have agreed to pay the $900,000 needed to fix the dam. The bad news: It’s going to take a while.

In the meantime, residents of this eclectic community tucked away in the woods near Manassas are worried about plummeting property values and spending summer weekends weeding mud flats full of snakes rather than swimming and water-skiing. Even worse, some say: In a neighborhood with both tarp-patched fishing shacks and big new homes with three-car garages, they lost the thing that always brought them together. They all live there for the lake.

The Lake Jackson community in Prince William County lacks a key feature that made it a great place to live — the lake. (Katherine Frey/The Washington Post)

“A lot of people I don’t see anymore,” said Barbara Newton, who has lived on Lake Jackson since the early 1970s. “It’s like we all disappeared.”

“These are people that bought homes so they’d have waterfront property,” Nohe said. “They made investments. And they want to go out and fish, go out in boats.”

Many complain that their taxes don’t reflect what they see out their wall-to-wall windows, either. Taxes on her waterfront lot are about nine times higher than those on her other lot not directly on the lake, said Sandra Dutemple, who has lived there 50 years. “I’m not saying I won’t pay it. But I don’t have waterfront now. I have vegetation-front.”

A tough row to mow

Neighbors had already waited through low water levels while the county did surface repairs to the dam in 2010 and 2011. But after the 2011 earthquake, residents noticed the lake getting lower, and in 2012, workers found water pouring through “toe drains” at the base and seeping from the downstream face of the dam. The gate was opened to relieve pressure on the dam that might worsen any leaks, and the lake began to disappear.

It has now narrowed to a fraction of its former size and in the deepest spots is only about eight feet, neighbors said.

Nohe hopes the work might be completed by 2014.

Some residents asked whether the county would pay to dredge the silt piling up in the lake and remove the plants as part of the repairs, but the answer was no. That’s why on a typical day at the lake now, the roar of lawn mowers has replaced that of outboard motors.

“It’s overwhelming,” said Margie Roche, who trims alligatorweed and thirsty grasses in shifts with her push mower. If they don’t cut the weeds, some of which are now eight feet high and have three-inch-thick trunks, it will ruin the lake when the water comes back.

So they mow — carefully, in the oozing mud — and they bulldoze, and they whack.

‘Caught in time’

In one of the fastest-growing counties in the country, where many people live in almost identical new homes on almost identical new streets, the Lake Jackson neighborhood is a throwback. “You almost feel like you’re caught in time here,” said resident Jodi Perry.

The dam was built on the Occoquan River in 1927 to generate power, creating a lake on what had been farmland and timber (and perhaps a few moonshine stills). When that didn’t turn enough of a profit, developer Charles Alpaugh built tiny log cabins with stone chimneys to sell as weekend summer getaways for Washingtonians. Now there are several hundred homes clinging to the steep hills under tall trees, most of them used year-round, many expanded far beyond the original footprint with wraparound decks to capture the view.

“As the crow flies it’s only about 25 miles from Washington, D.C.,” Roche said, “but you feel like you’re back here in the middle of the woods.”

There are Tysons Corner businessmen and good ol’ boys living next door to one another, Nohe said. There are volunteer firefighters and poets and doctors and concert pianists and retired soldiers. Dutemple can tell stories about many of the houses, like the one she said was used as a safe house for Russian spies who defected, the one that has a tree growing out of it (“He was artistic.”) and the one she thinks used to be a meth lab.

People name their houses and hang little wooden signs: Heron Hill, Crooked Wood, Frog Hollow. They have rusting swing sets in their yards, and wishing wells, and carefully tended terrace gardens, and hammocks, and concrete gnomes, and big hot tubs.

“Right now you would never be sitting here without hearing boats and Jet Skis and people hooting and hollering to come fishing with them,” Perry said. “The lake is definitely our ‘Cheers,’ the place you walk in and everyone knows your name.” It’s the thing that brings everyone together and keeps them connected, she said.

If this were a normal summer day, Perry said on a recent early afternoon, “I would have already probably had a beer. Someone would have pulled up to my dock and said, ‘Let’s go, I’m off today, let’s take a ride down the river.’ ” There were always birthday parties at the sandy beach area, “always grilling, cocktails flowing, a lot of boats.”

She hasn’t been able to do her boat-in theater this year, when she projects movies onto a 12-foot screen and neighbors watch from the lake, bobbing gently on the water.

“It’s just so sad,” Dutemple said. “You don’t hear a boat. You don’t hear children giggling as they play in the water.”

Many of the homeowners said they know they’re lucky to live there, and they try to laugh about the mud. Marcia White, who has lived there 40 years, said she wants to set up a croquet court on the new island in the middle of the lake.

“Or throw all the for-sale signs out there,” her partner Lois Lower said.

Dutemple said: “The insides of our homes are cleaner than they’ve ever been. We don’t go outside anymore.”