The construction of small low-head mill dams, locks and dams, and large hydroelectric dams over the past two centuries substantially limited the range of migration for fish (Walburg and Nichols 1967). For example, by 1852, 11 locks and dams had been constructed between Fayetteville, North Carolina (river kilometer 220) and the modern day site of Buckhorn Dam (river kilometer 300) to aid the passage of company ships bound for the coal fields of the Deep River Coal Company (Thompson 1852). Upstream passage was limited except during boat lockage and possibly during extended periods of high flow (Nichols and Louder 1970).
There are currently more than 1,100 dams in the basin (North Carolina Dam Inventory 2012) These major dams were identified from the National Inventory of Dams, the Army Corps of Engineers, dams that NOAA deems significant to diadromous fish conservation, and Google Earth).
The most prominent obstructions existing today are the three locks and dams in the middle basin constructed between 1913 and 1934 and operated by USACE. These lock and dams were built for navigation purposes but now serve primarily to create pools for municipal and industrial water supply withdrawals.