Study Background and Description

Following Board of Supervisors (Board) approval of the formation of the Task Force on the Future of Lake Accotink in May 2023, the Task Force reviewed past dredging studies and county staff recommendations to ensure that all options have been considered to preserve Lake Accotink in the most sustainable, equitable, and cost effective manner. The Task Force concluded its work and reported its findings to the Board on December 12, 2023. Task Force meetings, video recordings and meeting minutes can be found at Task Force Meeting/Materials Archive. Task Force’s report is located at Lake Accotink Findings Report.

On January 23, 2024, the Board approved Task Force’s findings which provided a path forward that has the potential to preserve Lake Accotink for generations to come. This path forward also revealed the need for additional study and analyses of various options identified for long-term preservation of Lake Accotink as a smaller lake. This mainly includes dredging and maintaining a smaller lake, use of dredged material on-site, and creating a wetland and grassland area. These alternatives will be evaluated in a preservation (feasibility) study with community input.

DPWES has been working with an interdisciplinary team of County staff, United States Geological Survey (USGS) staff, and a team of consulting engineers, scientists, and professionals to define the scope and appropriate approach to support the Lake Accotink preservation as a smaller lake as requested in the Preservation of Lake Accotink Joint Board Matter (Board Matter), presented and approved by the Board on January 23, 2024.

Subsequently, DPWES issued a task order to a consultant in July 2024 for the sedimentation study and the Board approved funding for USGS for their scope. A second task order was also issued in July to a consultant for outreach and community engagement. Lastly, using feedback from the recent online survey, DPWES updated the feasibility study scope and schedule. The feasibility study will commence in early April. The community engagement plan is provided in the Public Engagement website under Additional Resources.

The Lake Accotink team is committed to having a robust and inclusive public outreach and engagement plan for the study, to include increased transparency during the study phase. The team updated the community engagement plan to incorporate public comments received in the survey to enhance outreach and engagement during the Lake Accotink Preservation study for a smaller lake.

Lastly, Fairfax County Park Authority has initiated work with a consultant team to assess the condition of the Lake Accotink dam and identify any maintenance needs to support preservation of a smaller lake for the foreseeable future. The consultant team has completed the assessment of the earthen embankment part of the dam. Although efforts for the inspection of the concrete part of the dam, including the stilling basin, has been initiated, work could not be continued because of the malfunction of the sluice gate which regulates the water level in the lake. Currently, the issue with the sluice gate has been identified and efforts are underway to repair its stem.

Comments on Smaller Lake Accotink Preservation Study

We value your comments and input. Therefore, comments can be submitted via email to the project manager, Turgay.Dabak@fairfaxcounty.gov, or by US Mail to Fairfax County DPWES – Lake Accotink Preservation Study, 12000 Government Center Parkway, Suite 449, Fairfax, VA 22035.

Lake Accotink Background

Lake Accotink was constructed by the United States Army in 1940 as a freshwater supply for Camp Humphreys (now Fort Belvoir). Intense development in the 30 square mile watershed draining to the lake following World War II resulted in the lake losing 50 percent of its capacity. This was due to continued development in the watershed, mostly prior to the issuance of stormwater management regulations in late 1980, which increased overland runoff eventually causing streambank erosion and contributed significant amount of sediment to the lake. A second wave of development in the 1960s and 1970s added significant sediment to the lake. The Fairfax County Park Authority (FCPA) conducted a study in 1982 showing that the lake volume had been reduced to about 25 percent of its original capacity. The FCPA dredged the lake to restore capacity in 1985. By 2001 the lake had filled up again with sediment at a rate of more than 17,000 cubic yards per year. The Fairfax County Department of Public Works and Environmental Services (DPWES) partnered with FCPA to dredge the lake again in 2008. Analysis in 2016 estimated that the lake is now filling up again at about 23,000 cubic yards of sediment per year.

Lake Accotink Location

Lake Accotink is located in the Braddock Magisterial District in the Accotink Creek Watershed.

Map of Lake Accotink

What To Expect

Field studies, stream sediment and flow measurements, dam assessment and public outreach will take place through 2027. Please follow preservation feasibility study developments on this website and community engagement opportunities on the Public Engagement website. Dredge design and permitting will start after the completion of the preservation study and the selection of the preferred alternative.

For more information, please visit the following:

• Task Force Lake Accotink Findings Report
• Task Force Meeting/Materials Archive
• Lake Accotink Dredging - Results from April, 2023, Community Survey
• Lake Accotink Dredging Program Review, February 2023 (Video) | Presentation Slides
• Lake Accotink Dredging Public Meeting February 10, 2022 (Video) | Presentation Slides
• Lake Accotink Dredging Project Overview Zoom Meeting: December 10, 2020 (video)
• Lake Accotink Sustainability Plan
• Lake Accotink Sustainability Update September 2019
• Lake Accotink Master Plan Revision
• Alternative Evaluation - July 29 and August 5, 2021
• Alternative Analysis Report Lake Accotink Dredging Project December 23, 2021
• Project Update Meeting - February 10, 2022
• Dredge Program Cost Summary
• Offline Lake Construction Cost Summary

Contact

For more information, please email Project Manager Turgay Dabak, Stormwater Planning Division, Department of Public Works and Environmental Services, or call 703-324-5500, TTY 711.