Lake Accotink's "Smaller Lake" Options Aren't as Small as They Sound

If Lake Accotink shrinks to its "20-acre option," how much water would be left when you walk the loop?

More than the label suggests. In the Smaller Lake Accotink Preservation Feasibility Study, the "40-acre," "30-acre" and "20-acre" labels refer to the deep area that would be dredged. They don't measure the lake as a whole. Under the smallest option, the county's consultant still shows 32 acres of open water.

That gap between the label and the outcome shapes the whole debate over Springfield's lake. It also changes how a resident might read the three choices on the table.

What the Three Labels Actually Measure

Arcadis, the study's engineering consultant, posted a preliminary quantity sheet dated June 8, 2026. The sheet starts from one baseline: the lake's existing contiguous open water covers 40 acres. Every option is measured against that figure.

Arcadis defines open water as the deep area plus a channel area. In all three options the channel is dredged to about 4 feet. The wetland acres are islands built inside the lake, including new islands around the deep area and fill behind the island that's already there. Under the 20-acre option, the shoreline you walk past stays where it is. About a fifth of today's open water becomes island and wetland, and the deep, boatable center gets smaller.

The county's FAQ fits this reading. It says part of Lake Accotink "may become marshland," depending on the final outcome. The FAQ lists what those areas would do: filter runoff, support wildlife habitat, reduce long-term maintenance compared with open water, and keep some aesthetic and recreational value for park visitors.

Where the Dirt Goes Decides the Difference

Once the labels are read correctly, the real difference between the options shows up in the sediment. It's a question of how much comes out of the lake and how much has to leave the park.

The Arcadis sheet estimates dredging and off-site disposal at three possible depths for the deep area: 4, 6 and 8 feet. At each depth, the smaller options need less dredging. The bigger change is in disposal, because the smaller options reuse more of the dredged material to build the wetland islands.

• At 4 feet: the 40-acre option dredges 89,000 cubic yards and disposes of 67,000. The 20-acre option dredges 77,000 cubic yards and disposes of none, because all of it is reused on site.
• At 6 feet: 205,000 dredged and 183,000 disposed for the 40-acre option, against 131,000 dredged and 37,000 disposed for the 20-acre option.
• At 8 feet: 324,000 dredged and 302,000 disposed for the 40-acre option, against 189,000 dredged and 95,000 disposed for the 20-acre option.

The 30-acre option falls between the two at every depth. At 4 feet it reuses 45,000 cubic yards on site, against 22,000 for the 40-acre option and 94,000 for the 20-acre option. Arcadis notes that all of these quantities are approximate, based on preliminary measurements, and subject to change.

The county's materials show the dredging process in three steps: site preparation, dredging, and dewatering the sediment. From there, material goes one of three ways: reuse on site, wetland construction, or off-site disposal. Disposal is where the cost has grown.

In a June 14 viewpoint in Annandale Today, Paul Gilbert gave the cost history. He is a former executive director of NOVA Parks who lives blocks from the lake. He wrote that dredging was estimated at $30.5 million in 2019 and $95 million in 2023, partly because the planned sediment volume rose from 350,000 to 500,000 cubic yards and partly because a site for drying the dredged material was lost before it could be trucked away. In its January 2024 summary, the Board of Supervisors cited an estimated $395 million to keep the full lake for 25 years.

Islands built from the lake's own sediment avoid a large share of those trucking and disposal costs. That helps explain why every option the study models keeps the dirt in the park whenever it can.

Why the Lake Keeps Filling In

The study's bathymetry comparison covers March 2011 to March 2026. It shows 174,120 cubic yards of deposition, 2,020 cubic yards of erosion, and a net fill of 172,100 cubic yards. The county last dredged the lake in 2008. Before that, it dredged in 1985.

According to the county FAQ, most of the sediment comes from stormwater in Long Branch and Accotink Creek. During heavy storms, water overflows the stream channels, erodes the banks, and carries the soil downstream into the lake. Fairfax County's Department of Public Works and Environmental Services is restoring eroded stream channels upstream. The feasibility study is also looking at an offline lake and at trapping sediment before it reaches the lake.

The dam is part of the study too. The county's dam assessment found the spillway and stilling basin in fair condition, with some areas in poor condition. It concluded that the dam can keep operating with targeted repairs, but the spillway needs substantial improvements to pass flood flows safely. The FAQ says there are no plans to remove the dam, though some modification could be needed depending on the final lake layout.

The county is also paying for better data before it commits. The Board's July 16, 2024 meeting package proposed a four-year sediment-monitoring agreement with the U.S. Geological Survey. The agreement covers FY 2025 through FY 2028 and totals $1,140,200, including a $50,000 contribution from USGS.

Who Is Asking for 40

The smaller-lake approach started with a Board vote. On January 23, 2024, the Board of Supervisors unanimously supported a motion from then-Braddock Supervisor James Walkinshaw to advance the smaller-lake option. The Connection quoted his statement that day. He called the option "a key finding developed by the Task Force on the Future of Lake Accotink" and said it "meets the community's desire to preserve the lake sustainably." Walkinshaw now serves in Congress. The same Board action kept a $60.5 million commitment in the advertised FY 2025–FY 2029 capital improvement program.

The study's second open house took place on Saturday, June 6, 2026, at Kings Glen Elementary on Danbury Forest Drive. Annandale Today reported that Walkinshaw attended, along with Supervisors Rachna Sizemore Heizer of Braddock and Rodney Lusk of Franconia. In its open-house report, the county said it received five paper comment forms and several pieces of verbal feedback. Most comments favored keeping the lake larger, "specifically 40 acres," and several came from people who grew up near the lake or have owned homes in the area for a long time.

Gilbert made the same case in his viewpoint:

"A 20-acre lake is not Lake Accotink – it is a pond."

In the same piece, he put the park at 250,000 visitors a year and grouped it with Burke Lake and Lake Fairfax as the three lakefront parks that anchor the Park Authority system. Read against the Arcadis table, the debate looks narrower than that line suggests. The choice is between a 40-acre deep area and a 20-acre one, with roughly 32 to 40 acres of open water either way. Under the smallest option, open water would still cover 32 acres of the park.

The county contacted several groups during the study, including Friends of Lake Accotink Park, Save Lake Accotink, the Lakeside Cluster Homeowners Association, and Friends of Long Branch Stream Valley. Save Lake Accotink formed in 2018, Gilbert wrote, after a county proposal to give up the lake to save money.

A Longer Calendar Than One Season

At the open house, the main confusion was over when the lake's size will be decided. The county's FAQ sets out the sequence:

1. The initial feasibility study is expected to finish by the end of 2026 or in early 2027.
2. The study will be updated at the end of 2027 with more field-monitoring data.
3. The Board of Supervisors gives direction after that, so the FAQ says the final decision "may not occur until sometime after 2027."
4. The Board decides funding once the study is complete. The county plans to seek grants, low-interest loans and partnerships.

When construction does come, the FAQ says the park will likely stay open with some areas closed. The extent of those closures will be set once construction plans for the chosen option are drawn up. To get meeting notices, the county's Engage Fairfax County project page offers a subscription.

The lake's shape won't change this fall. The only change on the Park Authority's list right now is a repair. Its October 30 park alerts said the bridge near the marina was closed for repairs and was scheduled to reopen November 6, weather permitting.

At HOMEGROWN The McDonald Etro Group, we keep track of what's changing in the parks and places our Springfield neighbors use every week. Lake Accotink is one of them. If you live near the lake and want to talk through how the study's timeline fits your plans, we'd be glad to hear from you, and you can get your instant home valuation whenever you're ready.