Lower Usuma is the name of a dam on the Usuma River in Nigeria . It was built in 1990 north of Abuja , the new capital of Nigeria, and supplies the city with drinking water .

The dam is located about 15 kilometers northwest of Abuja at an altitude of 570 meters. The lake is 3.5 kilometers wide and 3 kilometers long and holds 120 million cubic meters of raw water. The water flows to five waterworks , where the water is treated before it is sent to Abuja. The total capacity of the waterworks is 10,000 cubic meters per hour.

The lake also receives water from the Gurara Dam . It is located 75 km north of Abuja. Through it, water is carried from the upper reaches of the Gurara to the capital.