Merced River/Falls Hydroelectric Projects

Lower Merced River, California.

Project(s) Profile & Licensee(s)

The Merced River Hydroelectric Project (P-2179) (owned by Merced Irrigation District (MID)) is being relicensed concurrently with the Merced Falls Hydroelectric Project (P-2467) (owned by Pacific Gas and Electric Company, but operated by MID). These two FERC Projects are located next to each other on the Merced River in Mariposa County, California.

The P-2179 Project: Two dams, the uppermost New Exchequer Dam (River Mile [RM] 62.4, creating 1+ million acre-feet Lake McClure Reservoir) and then McSwain Dam (RM 56.1, creating a much smaller McSwain Reservoir). Both dams have Powerhouses and there are various recreation facilities around these reservoirs. The installed capacity of the Project is 103.5 megawatts.

The P-2467 Project: Consists of Merced Falls Dam (RM 55.0), a Powerhouse, and a Reservoir that receives water directly from the P-2179’s McSwain facility. The P-2467 Project is dependent on water released from the P-2179 Project, the dam has an inactive fish ladder, and the installed capacity of the Project is 9.0 megawatts.

Crocker-Huffman Dam: Crocker-Huffman Dam (RM 52.0) is owned by MID, a non-FERC irrigation dam, and 3 RM downstream of Merced Falls Dam and P-2467 Project. MID operates this dam in tandem with the upstream FERC projects, and diverts 2,000 cfs from the Merced River into MID’s Main Canal during the 6-8-month irrigation season. This dam also has an inactive fish ladder, is the current limit of anadromy, and creates about an equal amount of upstream riverine and reservoir habitat. Cold water refugia for anadromous fish exists upstream of Crocker-Huffman Dam, should fish passage become re-established.

Federally Threatened - Listed Species/Species of Concern

  1. The distinct population segment (DPS) of California Central Valley (CV) steelhead (Oncorhynchus mykiss) and its critical habitat;
  2. The evolutionarily significant unit (ESU) of spring-run Chinook salmon (O. tshawytscha), when determined by NOAA Fisheries to be present in the Merced River;
  3. The DPS of North American green sturgeon (Acipenser medirostris), when determined by NOAA Fisheries to be present in the Merced River;
  4. The ESU of CV fall-run Chinook salmon (O. tshawytscha) [Species of Concern]; and
  5. Any resident rainbow trout (O. mykiss) (as this form may exhibit an anadromous lifestyle periodically).

FERC Relicensing Status

Integrated Licensing Process since November 3, 2008: Currently, FERC’s issuance of the “Ready for Environmental Analysis” Notice is imminent (April/May 2014). NMFS is developing Federal Power Act Section 10(j), 10(a), and to exercise/not exercise Section 18 fish passage prescription.

Resources

Federal Energy Regulatory Commission, FERC eLibrary: Dockets P-2179 and P-2467.

MID Relicensing site:  http://www.eurekasw.com/MID/default.aspx.