Despite its partial status as a National Wild and Scenic River, the Merced River has many dams and irrigation diversions. New Exchequer Dam is the largest dam on the river and forms Lake McClure, which holds of water for irrigation, flood control and hydropower generation. This modern structure was preceded by the old Exchequer Dam forming Exchequer Reservoir. The old concrete arch dam, completed in 1926, was flooded out when the new concrete-faced rockfill dam was built in 1967, but occasionally reappears during periods of low water.