The Parowan-Cedar City drainage basin, Iron County, Utah, includes about 1,100 mi2 (square miles)(2,800 km2 [square kilometers])--520 mi2 (1,300 km2) in the Parowan basin and 580 mi2 (1,500 km2) in the Cedar City basin. Parowan and Cedar City Valleys are structural depressions formed by northeast-trending faults. Parowan Valley is essentially a closed basin, whereas Cedar City Valley is drained by two gaps in the mountains bordering the west side of the valley, and a small part of Cedar City Valley is drained at a gap at the south end. Water flowing into the basin from the highlands to the east is used to irrigate lands near Cedar City, Parowan, Paragonah, and Summit. The surface-water outflow from the basin is negligible.