TCC and T18 Upper Feather River Dams Fault Exploration, Indian Creek Fault (ICF)

The California Department of Water Resources is conducting the TCC and T18 Upper Feather River Dams Fault Exploration project to evaluate past tectonic activity on the Indian Creek Fault (ICF) to ensure the future safety of Antelope Dam. The work is located in Plumas County within the Mt. Hough Ranger District, specifically at two sites, T-CC and T-18, situated approximately 1 mile and 3 miles upstream of Antelope Dam along Indian Creek. The project involves preliminary subsurface geologic exploration using hand augers or post-hole tools, followed by the excavation of up to two trenches at each location to define the history and location of the fault. Operational requirements dictate that preliminary work must be completed within one day, and no hand-dug locations may be left open. Trenches will remain open for a maximum of four weeks at each site, with tarps used to temporarily hold soil during the process. Upon completion, the sites must be restored to their original conditions using excavated spoils, straw, and native seed, following the direction of the Plumas National Forest. This project is classified under a Class 4 exemption for minor alterations to land. The primary point of contact for the project is Engineering Geologist Leah Feigelson.