The Erfenis Dam is an earth-fill type dam located in the Free State province of South Africa, on the Vet River, near Theunissen. It was established in 1960 and its primary purpose is for irrigation use. The hazard potential of the dam has been ranked high (3).

• List of reservoirs and dams in South Africa
• List of rivers of South Africa

• List of South African Dams from the Department of Water Affairs