The primary inflow and outflow is Accotink Creek, which is dammed on the south side, near a Norfolk Southern railway trestle.
Birds like seagulls, American robins, swifts, swallows, osprey, and occasionally bald eagles inhabit the park.
Red foxes, white-tailed deer and beaver dams are common along the edges of the lake along with cottonmouth snakes [dubious – discuss] and skinks.
[1] The discharge of sewage treatment plants in Fairfax and Vienna into the Accotink Creek eventually led to the contamination of the water to the point where it was no longer fit for drinking, and the Army sought to dispose of the reservoir.
[2] The area had been open to recreational use previously, but the Army's discontinuing use of the reservoir led to closing of the site, as guards were no longer posted.
[4] Although the reservoir had previously been declared surplus, the Army decided it wanted to retain title to the property in case of future need.
The Fairfax County Park Authority was the high bidder, and officially purchased the 242-acre tract, including the 100-acre lake, for $176,500 in April 1965.
[17] Local government meetings were held in February 2023, stating that the dredging project would cost Fairfax County roughly 400 million dollars over the next 25 years.