Cameron Run Watershed facts for kids

The Cameron Run Watershed (CRW) is a busy area in Northern Virginia. It covers about 44 square miles. Almost all of this area, about 95%, is developed. This means it has lots of homes and businesses. Most of the CRW is in Fairfax County. The rest is in Arlington County, Falls Church, and Alexandria.

The watershed has several streams, which are called "runs." It also has two lakes: Lake Barcroft (which is 137 acres) and Fairview Lake (15 acres). There are also four ponds. The CRW is divided into eight smaller areas called sub-watersheds. The western part of the CRW is in the Piedmont region. The southeastern part is in the Coastal Plain.

What Are the Main Streams?

Holmes Run is the most important stream that feeds into the Cameron Run Watershed. Other streams that flow into the CRW are Tripps Run, Backlick Run, Indian Run, and Pike Branch. All these streams eventually join Cameron Run.

Hunting Creek also joins Cameron Run just before it flows into the Potomac River.

Here's how the streams connect:

• Upper Holmes and Tripps Runs come from the northwest. They flow through Lake Barcroft. After the dam at Lake Barcroft, they become Lower Holmes Run.
• Turkeycock Run and Indian Run come from the west. They meet up with Backlick Run.
• In the lower middle part of the watershed, Backlick Run, Lower Holmes Run, and Pike Branch (from the south) all meet Cameron Run. Cameron Run itself comes from the northeast.

How Has the Watershed Changed Over Time?

For a long time, until the mid-1600s, the Cameron Run Watershed was covered in thick forests. Many beavers lived here. They built dams, creating lots of wetlands and ponds. These areas were perfect homes for many different plants and animals.

Who Lived Here First?

The first people to live in this area were Native Americans, specifically members of the Dogue tribe. They probably arrived around 1250 A.D., centuries before Europeans. They hunted, fished, and cleared land for farming.

Early European Impact

The first big changes to the watershed happened when Europeans arrived. They hunted beavers for their fur. This caused the beaver population to disappear. Without beavers, their dams broke down, which changed how water flowed and affected the whole ecosystem.

From the mid-1600s to the early 1700s, Europeans focused on growing tobacco. This crop was very hard on the soil. It made the soil less fertile and caused a lot of erosion.

In the 1720s, people from New York brought new farming ideas. They learned to let land rest (fallowing), use different seeds, and rotate crops. They also planted clover to make the soil richer. They used lime and animal waste as fertilizer and plowed deeper. These new methods helped the soil.

How Did Cities Grow and Affect the Watershed?

As the federal government grew in the late 1800s, more people moved to Northern Virginia. This led to more homes and the growth of cities like Arlington, Alexandria, and Falls Church. The first neighborhood was built by 1891. With more people, important services like water reservoirs and sewers were needed.

Water Supply for Cities

Lake Barcroft was created in 1915 to be a reservoir, which is like a big storage tank for water. It supplied water to the City of Alexandria until the late 1940s. As more people moved in, Alexandria needed even more water. So, in 1950, they built a dam on the Occoquan River to create the Occoquan Reservoir.

Dealing with Waste Water

In 1928, Fairfax County suggested a sanitation rule. However, all sewage was still dumped directly into streams and the Potomac River without being cleaned until the 1950s. The first sewer lines ran from Falls Church to the Potomac River. They followed Tripps Run, Holmes Run, and Cameron Run. These lines dumped raw sewage right into the Potomac River until 1954.

By the end of the 1950s, neighborhoods covered the northern part of the watershed. By 1965, most of the land that could be built on was already developed.

How Did Growth Harm the Watershed?

As more buildings and roads were added, the natural floodplains (flat areas next to streams that flood) were changed. Natural wetlands (areas where the land is always wet) were filled in or drained. This made space for roads, bridges, and houses.

Long ago, there were many marshes in the watershed. Today, only a few wetlands are left. From 1957 to 1992, the amount of forest in the watershed decreased by 32%.

Environmental Protection Laws

Developers built in the lower part of the CRW in the late 1940s and early 1950s. At that time, there were no rules about how building projects would affect the environment. It would be more than 20 years before the National Environmental Policy Act (NEPA) became law in 1969. NEPA was one of the first laws to protect our environment. It makes sure that the government thinks about the environment before starting any big projects. Now, any new building or highway must have a detailed NEPA review before it can be approved.

Many natural stream channels were put into pipes. This created a network of storm sewers and culverts (tunnels for water). Cameron Run itself was made straighter and even moved to make room for the Beltway and Route 1 highway expansions.

What Efforts Have Been Made to Improve the Watershed?

All the building and changes (like paved surfaces, straightened streams, and storm sewers) led to frequent flash floods in the lower part of the watershed. The soil here also erodes easily, and there are often heavy rainstorms. These things made flooding worse.

The county built special flood-control channels in lower Holmes Run, lower Backlick Run, and Cameron Run. However, these straightened channels are wider than natural streams. They are also disconnected from the floodplain. Normally, floodwaters would soak into the floodplain soil and refill groundwater. But in channelized streams, the water rushes quickly downstream instead.

Flooding at Lake Barcroft

The original dam at Lake Barcroft worked until 1972. That year, heavy rain from Hurricane Agnes caused very high water. It washed away the earthen part of the dam, draining the lake.

After this damage, the Lake Barcroft Watershed Improvement District (LBWID) was formed in 1973. This group acts like a state agency. It maintains the dam, manages the lake's water quality, controls water released from the dam, and works to improve the environment around the lake. The LBWID must keep the lake's water level almost constant. The dam releases the same amount of water it collects from 14.5 square miles of Fairfax County and the City of Falls Church. The dam is not designed to control floods.

After major storms like Hurricane Agnes (1972) and Hurricane Eloise (1975), and other flash floods, the United States Army Corps of Engineers studied the area. This led to Cameron Run being straightened. A federal flood control project was planned, but it was stopped due to land issues between Fairfax County and Alexandria. These issues were solved in 1973. Then, Alexandria used its own money to straighten Cameron Run upstream of the Capital Beltway.

Recent Flooding and Future Plans

A very big rainstorm happened from June 25–28, 2006. This caused extreme flooding in the Cameron Run Watershed. The United States Army Corps of Engineers (CoE) was asked to study the watershed. They wanted to find the best way to prevent future floods, especially in the Huntington, Virginia area.

From their 2009 study, the U.S. Army Corps of Engineers suggested building a levee. A levee is a wall built to prevent a river from overflowing. This levee would be 2800 feet long. It would be 15 feet high and 10 feet wide at the top. It would also have a pumping station to move water back into Cameron Run.

In 2012, voters approved money for stormwater projects. The design for the levee was planned to finish by January 2014, and survey work was to start in July 2014. The whole project was expected to take 3–5 years to design and another two years to build.

There was another major flood from the remnants of Tropical Storm Lee in September 2011.