The North Fork Stanislaus River Hydroelectric Development Project is a joint development project by Northern California Power Agency (NCPA) and Calaveras County Water District (CCWD). CCWD is the Licensee and NCPA is the Project Operator. The North Fork Stanislaus River Project combines water usage and electric power in an environmentally sound manner, plus provides recreation for Californians. Spanning 60 miles of the western slope of the Sierra Nevada, the Project ranges from the North Fork Diversion Dam at the alpine elevation of 6,700 feet to the Collierville Power Plant in the North Fork Stanislaus Canyon at 1,099 feet. In developing the project, NCPA and CCWD worked with the Federal Energy Regulatory Commission (FERC), U.S. Army Corps of Engineers, U.S. Fish & Wildlife Service, U.S. Forest Service, U.S. Bureau of Reclamation, California Department of Fish and Game, California Department of Water Resources, and various other federal, state and county agencies to create a multipurpose project of maximum benefit to mankind and the environment.


Melting snow and the runoff of summer thunderstorms collect in the New Spicer drainage basin and flow into the New Spicer Meadow Reservoir. Additional water from the North Fork Stanislaus River is diverted to the reservoir via a two-mile tunnel from the North Fork Diversion Dam. Water is released from the New Spicer Meadow Reservoir to satisfy recreational needs, fish flow, domestic water, and irrigation usage, and to meet NCPA’s energy demand for power generation at the Collierville Powerhouse. This water flows into Highland Creek which meets the North Fork Stanislaus River.  Water is finally impounded in McKay’s Point Reservoir. A small diversion dam was constructed on Beaver Creek, a tributary of the North Fork Stanislaus River, to divert additional water from Beaver Creek into the McKay’s Point Reservoir.

From McKays Point, the water enters an 18-foot diameter, 8.3 mile tunnel. The water picks up the gravitational energy as it falls the distance of 2,270 feet from McKays Point to the Collierville Powerhouse. The energy is more than sufficient to rotate the two turbines and generators weighing 12 tons each at a speed of 450 rpm generating 253 MW total electrical power at maximum capacity. The electric power created by the generators is “stepped up” in voltage at the Collierville Substation, then transmitted to PG&E’s Bellotta Substation. NCPA built 40 miles of 230 kilovolt transmission lines to connect the Collierville Powerhouse with PG&E’s Bellota substation. The power is dispatched to NCPA members to help satisfy their electric energy requirements.

The NCPA’s Upper Utica Project consists of: (1) Lake Alpine Dam is formed by five small dams. The main dam is a 49-foot high rock fill dam on Silver Creek. The Lake Alpine Dam forms a 4,117-acre-foot reservoir with a surface area of approximately 73 acres. (2) Union Reservoir is formed by seven small dams. The main dam is a 33 foot high, rock-fill (with upstream masonry face) dam, on the North Fork Stanislaus River. It is located upstream of the Utica Reservoir. The Union reservoir Dam forms a 3,130-acre foot reservoir with a surface area of approximately 218 acres. (3) Utica Reservoir is formed by five small dams. The main dam is a 59-foot high, rock-fill (with reinforced concrete face) dam on the North Fork Stanislaus River. It is located upstream of the North Fork Diversion Dam. The Utica Reservoir Dam forms a 2,334 acre foot reservoir with a surface area of approximately 241 acres.

There are no hydroelectric generation facilities at this project as the dams and reservoirs described above regulate water flows for downstream power generation.  The Upper Utica Project is located in the Stanislaus National Forest managed by the U.S. Forest Service.


NCPA at the Hydroelectric Facility