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Wednesday, February 14, 2018

Supervisors to weigh cost of saving Lake Accotink

The dam at Lake Accotink.
Is Lake Accotink such a huge asset that it should be saved regardless of the cost? If nothing is done and the lake fills up with sediment, how will that affect property values? If the lake is dredged, how will the community deal with thousands of trucks carting dirt through neighborhood streets?

Those are some of the key questions raised by residents at a meeting Feb. 13 hosted by Fairfax County supervisors John Cook (Braddock) and Jeff McKay (Lee).

The future of Lake Accotink must be decided now, because the pace at which upstream sediment is washing into the lake is accelerating.

Options on the table

Cook outlined the five options identified in a Park Authority study:

A – Do nothing and let the lake disappear on its own, which would happen by 2025. That would cost virtually nothing, other than $13,000 annually on dam maintenance.

B – Dredge the lake every time it needs to be done. The last dredging was done in 2010 at a cost of $9 million. The next one will cost $21 million because the quarry that had been used to hold the sediment is no longer available. The period between dredging operations would continue to shrink. According to Cook, this would be a “temporary fix,” with the cost making it no longer feasible.

C – Create a forebay upstream to catch the sediment before it reaches the lake and dredge it annually. This would result in a deeper lake that would last 30 to 35 years. The initial cost to dredge the lake would be $45 million. Dredging the forebay would cost about $700,000 to $750,000 a year.

D - Install a series of “beaver dams” upstream to capture sediment. The lake would still fill up in five years, so this wouldn’t be a permanent solution.

E – Remove the dam, which would transform the lake into a stream. That would cost $11 million plus $26,000 annually to maintain the park.

F – Turn the lake into a single channel and create a new, smaller lake next to but separated from it by a berm. The new lake would be a little less than half the size of the current lake and could still be used for boating. It wouldn’t fill up with sediment because Accotink Creek wouldn’t flow into it. This option would cost $13 million.

A haven for wildlife

Community member Shane Schroeder formed a group, Save Lake Accotink, to advocate for option C. “Lake Accotink is an invaluable resource,” the group states in a flyer. It provides opportunities for boating, fishing, and kayaking; supports wildlife, including nesting bald eagles; and prevents sediment from washing downstream and ultimately into the Chesapeake Bay.

A petition on the Save Lake Accotink website already collected at least 1,400 signatures.

The Park Authority doesn’t have the funds to pay for a dredging operation to preserve the lake, Cook told the approximately 200 people at the community meeting. So if that is the course of action approved by the BoS, funding would most likely have to come from a bond referendum presented to voters in 2019.

“Before we make that decision, we want to hear from the community,” Cook said.

“I’m emotionally attached to the lake,” McKay said. But retaining the lake in its current form would be a major expenditure, so “we have to understand how the community feels.”

“This is a Fairfax County gem,” he said. “I don’t care where this lake is. If we decide to save this lake, I will kill myself to get the money. We need a groundswell of support for whatever solution we come up with. Money is an important part of this, but it’s not the driver for me.”

Quality of life

While many of the residents said they want to preserve Lake Accotink, they expressed concern about the impact of a major dredging operation on their neighborhood.

Dredging would require as many as 12,000 truckloads of dirt moved from the lake bottom to another location outside Fairfax County. That would be noisy and disruptive and would damage neighborhood streets.

Residents of the Ravensworth community proposed modifying option C to move the forebay farther upstream and closer to Wakefield Park, so the trucks removing sediment could use Braddock Road. Cook said that idea is worth looking at.

If the lake goes away, the park would remain and there would still be opportunities for recreation, possibly including more trails. If the lake fills in naturally, the area would become a wetland. If the dam is removed, the park would consist of forest, meadow, and stream valley.

Once the future of the lake is determined, the Park Authority would revise the master plan for the park.

The downside of development

Several people asked if the lake could be saved by mitigating the sedimentation upstream.

That would be cost-prohibitive, Cook said. There is no specific source. The sediment in the lake comes from all the development – from a home addition to the beltway express lanes – that resulted in impervious surfaces, causing rainwater to wash dirt downstream.

The sediment choking the lake is from “50 years of development,” he said. “It’s our dirt from our backyard. We can’t tear things down to restore a natural watershed.”

A decision needs to be made this calendar year. Cook said. If dredging is to be done, a bond referendum would have to be on the 2019 ballot. By 2021 it would be too late.


  1. I think we should spend money on this lake rather than school teacher salaries, and other non-important items.

    1. If only we had some sort of a a meals tax...that might help fund ideas like this.

    2. Yes, please tax me more to keep a fake lake alive. That is what I want!!!!

    3. How about we just throw all the supervisors in there. Sort of like the swamp of Fairfax. They could all ponder on schemes of how to lessen our quality of life in the county.

    4. Adam: Too bad this matter didn't come up before the meals tax referendum. I'm confident that legions of voters who voted against the meals tax would have changed their minds just to save another amenity most of them will never use. - Sparky

  2. Seems like option F is a reasonable comromise. Still expensive one time cost, but it is a more permanent solution that doesn’t entail a high ongoing dredging operation, but maintains some of the things that people love most about the lake, such as the boating.

    Adam, once again you make just too much sense.

  3. Didn't grow up revering the lake like some, so option A seems smart to me. Maybe it could turn out like this amazing wetlands restoration park in Alexandria:

  4. As hard as it is to say this, from an environmental standpoint, the best option is E--removing the dam and reverting to the stream, which existed prior to the dam construction.
    Few things have such a fundamental negative impact on a river as a dam or culvert which disturbs the natural ecosystem.
    Dams block the movement of fish and other aquatic species, inundate river habitat, impair water quality, and alter the flow regime necessary to sustain river life. Many, perhaps most, of the more than 90,000 dams in the country are no longer serving the purpose that they were built to provide decades or centuries ago. The most effective way to restore a river or stream is to remove the dam. Moreover, as dams age and decay, they can also become public safety hazards, presenting a failure risk and a dangerous nuisance. And in the case of Lake Accotink, the cost of maintaining the lake by dredging seems absolutely prohibitive. Removal of dams is being done increasingly throughout the U. S. to allow for a more natural ecosystem.

  5. With option F
    But you have to consider the silt going downstream and how it will affect the lower Accotink Creek. There is a species of muscles that only live a mile or two downstream of the damn. How will the silt affect Pohick Bay, the Potomac River and ultimately the Chesapeake Bay?

    And the smaller lake can’t support the eagles. So we’d lose them.

  6. Seriously people want option C?

    Pave the damn thing and make it into a town Center like Mosaic

    or Eden Center Dos

  7. None of the options is ideal. Retaining the lake is a substantial financial cost to taxpayers and leaves a barrier to fish and wildlife movement. Breaching the dam would reconnect the stream for wildlife movement, but would incur the loss of the community value of the lake, sacrifice the wetlands at the head of the lake, and certainly cause the extinction of the last population of freshwater mussels in Accotink Creek.

    In 2017 the Virginia Department of Environmental Quality placed Accotink Creek under what is called a TMDL order to reduce the stormwater sediment that is smothering aquatic life. This may leave the county no option but to retain the lake so that it will continue to capture some of that sediment.

    Two cents of every Fairfax County property tax dollar are currently dedicated to stormwater controls and these funds are tapped to maintain other lakes. Bizarrely, for technical reasons that are hard to understand, the same funds are not available for Lake Accotink.

    Those who care about Lake Accotink and live nearby may consider the example of Lake Barcroft, where residents voted to create a Watershed Improvement District, paying additional amounts each year to support their lake -

  8. I'd prefer E & 26 K to maintain the park seems reasonable but 11 mill to take out the so called dam? Who's brother-in-law is gonna get rich off that deal? A is also acceptable to me.