The Haw River and the Deep River join to form the Cape Fear River. The Cape Fear is the largest water basin in the state and covers 9149 square miles and flows through 24 counties.
The Haw River flows through sections of six counties: Forsyth, Guilford, Rockingham, Alamance, Orange, and Chatham, and is approximately 110 miles in length. The Haw River receives the runoff and wastewater from several large municipalities including Greensboro, Reidsville, Burlington, Graham, Mebane, Chapel Hill, and Durham. The entire watershed covers 1526 square miles.
The Haw Watershed is a mix of rural and urban landscapes —-
agriculture (crop, pasture) 27%, forest 43%, urban 17.5%, other 13%.
There are six dams on the Haw River: Glen Raven at Altamahaw, Swepsonville (2), Bynum, and the Jordan Lake Dam. All these dams except Jordan Lake were built in the 1800’s to provide hydropower for textile mills, once a thriving industry on the Haw. Many of the mills are now closed, by hydropower is still produced at Altamahaw, Saxapahaw and Bynum. The 14,000-acre Jordan Lake reservoir was built by the Army Corps in the 1980’s for flood control and recreation. It has now become a sought-after source of drinking water for many municipalities in this fast growing region, despite its water quality problems.
The U.S. Department of Agriculture and the EPA have recognized for 20 years that sediment runoff resulting from human activities is the single most significant water pollutant. In 1982 the U.S. Soil Conservation Service estimated that 2 billion tons of sediment were being deposited in U.S. streams annually. Sediment impacts aquatic plants, adversely affects most aquatic animals (especially those with gills, including macroinvertebrates), and significantly alters the streambed, destroying habitat and spawning areas.
Threatened species on the Haw include the Squawfoot mussel and the Savannah Lilliput mussel.