The water in Lake Thoreau is finally high enough to allow crews to begin clearing sediment.
Delayed from last fall due to insufficient water levels, Reston Association now anticipates beginning the approximately four-week process of dredging Lake Thoreau’s Westcove next week.
Sediment testing was conducted this past Monday (March 30), and RA’s contractor, Lake Services Inc., is scheduled to start setting up the site during the week of April 6-13. Preparations will include the installation of safety fencing and erosion controls.
Construction equipment will be staged on the South Lakes side of the lake, requiring a closure of the pathway connecting South Lakes Shopping Center and Ridge Heights Road.
If the weather cooperates, the actual dredging operations will then take place from April 14 through 28, followed by about a week of work to restore the site.
“Residents should anticipate temporary pathway interruptions along South Lakes Drive during the project,” RA said in a project update. “On‑site signage will be installed in advance to help guide pedestrians and minimize disruption.”
RA estimates that it will need to remove 1,200 cubic yards of sediment from the Westcove area to restore Lake Thoreau to its original design. The lake currently has an average depth of 20.3 feet, but its deepest point extends down 38 feet, according to a February 2025 water quality report that reviewed all four of RA’s lakes.
Lake Thoreau was previously dredged in spring 2018, when RA removed approximately 4,200 cubic yards of sediment.
The dredging project will get underway just a couple of weeks after RA stocked Lake Thoreau with sterile grass carp to manage the invasive hydrilla that resurfaced last summer.
In accordance with a newly updated hydrilla management plan, RA’s watershed staff worked with the firm Southeast Pond Stocking to place 92 fish into the lake. Sterile grass carp are a herbivorous freshwater fish that are often use to control aquatic weeds like hydrilla.
Lakes Audubon, Anne and Newport were also freshly stocked with carp last week, RA spokesperson Cara O’Donnell told FFXnow.
Screenshots 1, 2 and 3 via Reston Association/YouTube
