This project is the first diversion on the Merced as it flows out of Yosemite Valley.
The existing Merced River project operates as a seasonal storage and peaking system throughout the year. The project consists of two developments – New Exchequer and McSwain – which in total include two dams, two powerhouses and associated switchyards, and appurtenant facilities, including recreation facilities.
Merced Irrigation District’s (Merced ID) Merced River Hydroelectric Project (FERC P-2179) is located on the Merced River in Mariposa and Merced counties, California. It consists of a major storage reservoir, New Exchequer Reservoir (also known as Lake McClure) with storage of just over one million acre-feet; New Exchequer Powerhouse at the downstream base of New Exchequer Dam; 9730 acre-foot McSwain Reservoir, which backs up the Merced River seven miles almost to the outfall from New Exchequer Powerhouse and which serves as an afterbay; and McSwain Powerhouse, at the base of McSwain Dam.
Located immediately downstream of McSwain Powerhouse is Merced Falls Reservoir, a 900 acre-foot reservoir owned by Pacific Gas & Electric Company. The Merced Falls Project (FERC P-2467) also includes Merced Falls Dam and, at the base of the dam, Merced Falls Powerhouse. The Merced Falls Project is operated in run-of-the-river mode, passing through the outflow from McSwain Powerhouse. Merced ID operates the Merced Falls Project for PG&E on a contract basis. Merced ID has a 100 plus cfs agricultural diversion, the Northside Canal, whose point of diversion is located within the Merced Falls Project boundary on the north side of Merced Falls Reservoir.
Approximately three miles downstream of Merced Falls Dam is Merced Irrigation District’s Crocker-Huffman Diversion Dam. Crocker-Huffman Diversion Dam serves as a diversion pool for Merced ID’s Main Canal diversion; the Main Canal has a capacity of approximately 2000 cfs. The main purpose of the Merced River Hydroelectric Project facilities is to provide agricultural water for Merced ID