17th century Cameron Run Watershed was heavily forested until the mid-17th century. A large beaver population created wetlands amid numerous ponds that provided habitat for a wide variety of flora and fauna. were the first human inhabitants of the area. It’s difficult to pinpoint exactly when they arrived—probably around 1250 A.D.--several centuries before the Europeans, trapping, fishing, and clearing land for farming.
18th century The first changes to the watershed came when Europeans wiped out the beaver population for their pelts, which led to deterioration of their dams and “changed the hydrology and ecosystem of the stream valley”. 670. In 1928,
Fairfax County proposed a sanitation ordinance, but all sewage was dumped untreated into the tributaries as well as the
Potomac River until the 1950s. by the end of the 1950s, residential subdivisions covered the northern half of the watershed, and by 1965, most land suitable for development had been built upon Developers were able to build in the lower third of the CRW in the late 1940s and early 1950s because there was no standard for environmental impact at the time. In 1969, the
National Environmental Policy Act (NEPA) took effect in 1969.
National Environmental Policy Act was "one of the first laws ever written that establishes the broad national framework for protecting our environment . . . to assure that all branches of government give proper consideration to the environment prior to undertaking any major federal action that significantly affects the environment". Any type of proposed building, including highways and structures, must undergo a thorough NEPA assessment before approval. Many of the natural stream channels were piped, resulting in a network of storm sewers and culverts. In particular,
Cameron Run was both straightened and moved to accommodate the Beltway and Route 1 interchanges and expansions. The effects of
urbanization, such as impervious surfaces, channelization, and storm sewers, led to frequent flash flooding in the lower portion of the watershed. Highly erodible soils and frequent, intense rainstorms also contributed to the flooding. The county addressed this problem by constructing flood-control channels in lower Holmes Run, lower Backlick Run, and
Cameron Run. The
Lake Barcroft Watershed Improvement District (LBWID) was formed in 1973 in the wake of the damage caused by
Hurricane Agnes the previous year. Today, the WID functions as a State Agency to maintain and operate the dam, manage water quality of the lake, manage the discharges from the dam and maintain and improve the environmental integrity of the watershed above the lake. By law, the WID must maintain the water level of the lake. The dam is designed and operated to maintain a nearly constant water level between 208.5 and 209 feet above mean sea level, and discharges the same amount of water it collects as runoff from 14.5 square miles of
Fairfax County and the
City of Falls Church. The dam is not designed for or operated in a flood control capacity. In response to two major rainfall events—Tropical Storms
Agnes (1972) and
Eloise (1975) in addition to flash flooding in September 1966, in which several adjacent properties were flooded—a report was commissioned by the
U.S. Army Corps of Engineers which eventually led to
Cameron Run being channelized. A federal flood control project was also recommended, but the plan was scrapped due to land boundary issues between Fairfax County and
Alexandria. The issue was resolved with a land transfer to Alexandria, in January 1973. Alexandria then used its own resources to channelize
Cameron Run upstream of the
Capital Beltway, not as a federal program. == Recent flood events ==