Lake Accotink Slated for Dredging
Thursday, December 29, 2005
It is going to take more than a year, but Lake Accotink is about to get a little deeper. An $8 million dredging project recently began with construction of a pipeline nearly three miles long that will carry slurry from the popular Springfield lake to a site in the Shirley Park industrial complex.
"If we didn't do something this year, we were not going to be able to allow boating starting in a year or so because it has gotten so shallow," said county Supervisor Sharon S. Bulova (D-Braddock). "Boating is very popular on the lake, but I can remember when you used to be able to go out a whole lot farther than you can now."
The lake "is doing its job," Bulova said, as a filter for the Chesapeake Bay.
The county awarded the dredging contract to Mobile Dredging and Pumping Co. of Chester, Pa. Jerry Vetter, executive vice president of the company, said that about 161,000 cubic yards of silt is expected to be removed from Lake Accotink. The slurry will be pumped through a 14-inch-wide pipeline that will run from the park, along the Norfolk Southern railroad line, across Backlick Road and from there to Virginia Concrete Co. in the Shirley industrial park.
Finding a destination for the silt and a way to get it out the lake with the least impact on the surrounding community was a big issue, Bulova said.
"The county staff worked very closely with the community about a number of different options regarding removing the silt and figuring out where the silt would go and how the silt would get to where it was going," Bulova said. "People were concerned about silt being loaded onto trucks and then the trucks going through the neighborhoods. Then a very good solution was reached when Virginia Concrete said it was interested in having the silt."
She said the company will use the silt as fill on its property.
Dredging is scheduled to begin in March after the pipeline is finished and the industrial park site is ready to accept the slurry and drain the water from it.
"This is a big challenge," said Vetter. "We are pumping it nearly three miles."
The dredging will not disrupt recreational activities, Bulova said. Water will not have to be drained from the lake, so Lake Accotink wildlife such as birds and fish might be temporarily annoyed by the equipment and noise but will not be displaced.
"It is a really nice situation because we don't have to shut the park down," said Tawny Hammond, the park manager. "And there is not going to be 180 trucks a day hauling the silt out of the park. It really is a win-win situation for the community."
Vetter said that once the water is drained from the slurry, the dirt left over would be enough to create a pile the size of a football field more than 90 feet high. When the project is finished, the lake will have an average depth of six to seven feet.
"Right now we are anywhere from a foot in some areas to eight to 10 feet in others," said Hammond. "There are some deep pockets around the dam and the dike, but we average about three or four feet. The depth is a couple inches where Accotink Creek empties into the lake."
Hammond said the park has about half a million visitors a year -- a conservative estimate, she said. The man-made lake was created by the federal government in 1918 as a water source, Hammond said. She said when it was first built, Lake Accotink covered about 110 acres and held about 240 million gallons of water. When Fairfax County acquired the lake in 1965, she said, it still covered about 110 acres but was not as deep. Now it is about half its original size -- about 50 acres -- and is even shallower, she said.
"It was 23 feet deep when it was first built, but when the county purchased it, it was about 12 or 13 feet deep," Hammond said. "As Fairfax County developed in the '60s and '70s and '80s, the construction of highways and shopping centers and homes has made life in the area better, but it has accelerated the rate of siltation."
This marks the third time the lake will be dredged since the county bought it, Hammond said. It probably will need to be dredged again in about 10 years.