There are only two natural lakes in Virginia, Lake Drummond (in Great Dismal Swamp) and Mountain Lake (in southwestern Virginia).
In the past, there were more lakes in Virginia. Roughly 200 million years of steady erosion has provided enough time for streams to etch their way into every Virginia valley. The streams have drained whatever lakes may have formed long ago in the last major orogeny, when the Appalachian Mountains were lifted up and topography transformed.
Since the last uplift when Africa and North America collided, climate has been wetter and new lakes may have formed. Sea levels have also been higher, flooding over the Coastal Plain all the way inland to roughly modern I-95. However, such lakes were short timers; erosion has carved new outlets to the Atlantic Ocean or Gulf of Mexico and those lakes are now meadows or bogs. During that last Ice Age over the most recent 100,000 years, glaciers transformed the landscape and created the Great Lakes; Minnesota is the Land of Ten Thousand Lakes thanks to the glaciers. No ice sheets reached Virginia, however, and no new lakes were scoured out by the ice sheets south of Pennsylvania.
The two natural lakes present today appear to have been created by recent events. All other "lakes" in Virginia, including small ones such as Burke Lake in Fairfax County and large ones such as Smith Mountain Lake near Roanoke, are human-made reservoirs created by building dams and flooding valleys. Some watersheds - for example, the North Fork of the Shenandoah River, the Powell River, the Piankatank River, and the Blackwater River - have low volumes of impounded water today, but in the last 400 years dams have been constructed on nearly every Virginia stream.
Mill dams were built in the colonial era to power gristmills, grind limestone into plaster, and to saw wood. Most of the dams built for small gristmills have decayed and been washed away by storms. Almost all large lakes now visible in Virginia were made by humans damming streams to create reservoirs for hydropower, drinking water, flood control, or cooling water for power plants.
Impoundments made for transportation, industrial, hydropower, or municipal drinking water purposes are not natural lakes. The canal system for the Rappahannock River envisioned converting the river upstream to Kellys Ford into a series of slackwater pools, allowing boats to transport agricultural products to Fredericksburg. Dams along the James and Potomac rivers were also built, where it was cost-effective to increase water epth in the main river channel rather than build a canal parallel to the river.
Some of Virginia's largest lakes were built for energy production, rather than for transportation. Lake Anna was constructed to provide cooling water for nuclear power plant reactors, though the two nuclear reactors in Surry County are cooled by water pulled directly from the James River. In the Roanoke River watershed, Lake Gaston, Kerr Reservoir/Buggs Island Lake, Phillpott Lake, and the combination of Smith Mountain Lake/Leesville Lake were created for hydropower. The largest lake in Virginia on the New River, Claytor Lake, was also built to generate electricity. There are tiny hydropower lakes as well. The tiny Little River, just downstream from Claytor Dam, also was blocked to generate one megawatt of electricity for the City of Radford.
There are thousands of small impoundments created as farm ponds for watering cattle/horses, but Virginia has few large lakes for irrigation. Virginia has a wet climate, unlike the Western United States. No Virginia dam projects were esigned to provide irrigation for agriculture, so there are no dams built by the US Department of Reclamation such as Hoover Dam (which created Lake Mead near Las Vegas, Nevada). All Federal dams in Virginia were constructed by the US Army Corps of Engineers, justified primarily for flood control or hydropower.
Lake Moomaw, behind Gathright Dam on the Jackson River, was built in part to mitigate the pollution coming from the Westvaco paper mill at Covington. The philosophy was that "dilution is the solution to pollution," and water stored behind the dam could be released during low-flow periods in the summer to mitigate the waste being put into the rive downstream. A series of dams proposed on the Potomac River and its tributaries was justified as a means of diluting the sewage dumped into the river at Washington, DC. Those Potomac River dams were never constructed, and the Clean Water Act has forced polluters to reduce the waste dumped into the river rather than to rely upon dilution.
The change in the public's environmental consciousness in the 1960-70's has altered plans for new dams in Virginia. Transforming free-flowing rivers into flat-water reservoirs is no longer acceptable; the environmental impacts are now perceived as too significant. The Salem Church Dam, upstream from Fredericksburg on the Rappahannock River, was the last proposal to block a major stretch of free-floating river and create a new lake. It's rejection by the public, together with rejection of the dams on the Potomac, ended a 50-year period when large artificial lakes were built in Virginia.
In the future, there will be no more Occoquan Reservoirs; no new drinking water reservoirs will be constructed on the main stem of rivers. Even drowning small creeks can become so controversial that the project must be abandoned, as demonstrated by the failure of the King William Reservoir project. The wetlands and historic resources along Cohoke Creek in King William County will not be drowned to supply drinking water to Newport News.
Lake Anna was built to cool a nuclear power plant (in circle)
Source: ESRI, ArcGIS Online (2013)
two dams on the Occoquan river create a drinking water reservoir for Northern Virginia, but also block anadromous shad and herring from their natural spawning habitat upstream
Source: US Geological Survey (USGS), Occoquan 7.5x7.5 topographic quad (2013)
The new model for urban areas seeking a reliable source of surface water (as opposed to drilling wells for groundwater) is to dam a small tributary. A dam on Motts Run created a small reservoir of drinking water for Fredericksburg, and Henrico County is building a dam across Cobbs Creek to supply its urbanizing suburbs. Such small tributaries may lack adequate runoff to fill the reservoir regularly, but excess water can be pumped out of nearby rivers during winter runoff as an annual recharge source. Loudoun County has created the most dramatic example of how such runoff can be stored without creating a large lake, with plans to pump Potomac River water into old basalt quarries.
Instead of building new dams, public agencies are focused now on removing outdated dams that block fish migration, or are safety risks. Most of the small gristmill dams have been washed away by floods, and many small dams built before World War II have been breached. The US Fish and Wildlife Service and the Virginia Department of Game and Inland Fisheries are removing larger dams (including Embrey Dam at Fredericksburg), or installing fishways to allow anadromous/catadromous fish to cross artificial barriers. Hollywood and Pipeline rapids on the James River in downtown Richmond are spicier because of old dams, but Riverton dam on the North Fork of the Shenandoah River and McGaheysville Dam on the South Fork of the Shenandoah River were life-threatening hazards before removal.
Dam removal can be controversial. The Virginia Department of Conservation and Recreation revised dam safety requirements in 2012, and owners of many dams discovered that relicensing would require upgrading spillways or making other expensive repairs.
In 2012, the Lake Jackson Dam on the Occoquan River started to leak. That occurred a year after a 5.2 magnitude earthquake in Louisa County create enough motion to damage the Washington Monument, and the quake may have weakened the dam. Prince William County could have removed the 28' high dam completely, eliminating safety risks and restoring the natural flow of the river. However, eliminating Lake Jackson would have altered the character of the community surrounding it.
Local residents made clear that they preferred the recreational benefits associated with the lake, rather than a narrow stream. The county chose to spend close to $1 million to repair the dam, plus annual costs to maintain it - but declined to fund any dredging of the reservoir in order to improve boating and water skiing.1>
In Lynchburg, Liberty University discovered that the donation of Ivy Lake in 2008 provided not only a 112-acre recreational site for students, but also a financial burden for dam repair. The Virginia Department of Conservation and Recreation classified it as a high hazard dam, with 1,000 residents downstream at risk if the dam failed during a major storm. The engineer hired by Liberty University reported:2
The university considered removing the dam, rather than paying up to $3 million for repairs. An alternative was for nearby homeowners in Bedford County to contribute $1 million, half the cost of repair, since they benefit from the recreational opportunities of the lake and the water access adds value to their private property. There was little support from the homeowners for that option, or for simply breaching the dam and letting Ivy Creek flow without interruption.
In 2013, Liberty's engineers developed a lower-cost solution, the school agreed to pay $1 million to complete repairs as required by the state - but the deal also included transferring ownership of the lake to the nearby homeowners. The homeowners will absorb responsibility for future maintenance, while university students will get access to the lake - reversing the previous pattern, where the school paid all the costs for Ivy Lake while homeowners received substantial benefits.3
in 2013, Liberty University decided to transfer ownership of Ivy Lake to adjacent homeowners rather than drain the lake or accept responsibility for perpetual dam maintenance
Source: US Geological Survey (USGS), Boonsboro 7.5x7.5 topographic quad (2013)
One of the most unusual lakes in Virginia, Lake Tecumseh (also known as Brinsons Inlet Lake), was created when a 1789 hurricane created a new barrier of sand that altered the Atlantic Ocean shoreline. An open bay was quickly converted into a salt-water lake, which over time evolved into a 2-foot deep freshwater lake surrounded by wetlands. Because the lake was so shallow, its water was often turbid from bottom sediments stirred up by winds.
In the 1960's, the isolated lake was connected to Back Bay by a canal. That provided boat access to anglers and other recreationists, but the canal allowed sediment-rich water from Lake Tecumseh to degrade the quality of the northern portion of Back Bay. The lake would drain completely in the winter, and at other times when wind blew the water down the canal.
To block sediment from reaching Back Bay, in 2011 the US Fish and Wildlife Service built two low dams (weirs) where the Asheville Bridge Canal connected to Lake Tecumseh. For much of the year, the weirs now keep the water and its suspended sediment in the lake. At high water, the weirs are submerged and water flows freely between the lake and Back Bay. To maintain recreational access, the Federal agency built a boat trolley on rails, and provided a solar-powered winch to lift boats across the barrier. Lake Tecumseh is now a lake during low water, and an extension of Back Bay at high water.4
Lake Tecumseh is north of Sandbridge and Back Bay in Virginia Beach
Source: ESRI, ArcGIS Online
a solar-powered winch helps to portage boats across the weir at Lake Tecumseh
Source: Will Smith, Lake Tecumseh Weir Project presentation at 2012 Back Bay Forum
Lake Tecumseh in Virginia Beach
Source: US Geological Survey (USGS), Virginia Beach 7.5x7.5 topographic quad (2013)
1. "Lake Jackson Dam," Prince William County, http://www.pwcgov.org/government/dept/publicworks/environment/pages/lake-jackson-dam.aspx (last checked April 15, 2014)
2. "Engineer: Dam is 'high hazard'," Lynchburg News & Advance, February 5, 2013, http://www.newsadvance.com/news/local/article_3161cd14-7014-11e2-a656-001a4bcf6878.html (last checked April 15, 2014)
3. "Ivy Lake dam in need of costly repairs," Lynchburg News & Advance, February 5, 2013, http://www.newsadvance.com/news/local/article_33e49286-6f53-11e2-a539-0019bb30f31a.html; "Neighbors balk at Liberty University plan to lower Ivy Lake," The Roanoke Times, January 10, 2014, http://www.roanoke.com/news/article_d27034c0-7a68-11e3-9d61-0019bb30f31a.html; "Ivy Lake water level to be lowered during repairs," Liberty University, January 12, 2014, http://www.liberty.edu/news/index.cfm?PID=18495&MID=109414 (last checked April 15, 2014)
4. "Lake Tecumseh Weir Project," US Fish and Wildlife Service, http://www.fws.gov/northeast/virginiafield/partners/tecumseh.html; Caleb Kulfan, "The Lake Tecumseh Weir Project," 2013, http://www.fws.gov/northeast/virginiafield/pdf/partners/lake_tecumseh/20130430_Weir_Report_Caleb_Kulfan.pdf (last checked April 16, 2014)