Fault Rupture Hazard Assessment for North Haiwee Dam No. 2, Owens Valley, California

Chris Kemp and Scott Lindvall of LCI are co-authors on a technical paper titled “Fault Rupture Hazard Assessment for North Haiwee Dam No. 2, Owens Valley, California” with lead author Christopher Goetz of AECOM. Christopher Heron and Kevin Mass of Los Angeles Department of Water and Power, and Mark Olson of Advanced Geoscience are also co-authors on this paper.

A comprehensive investigation of local faulting was done to provide a deterministic assessment of the potential for surface fault rupture under or adjacent to the planned North Haiwee Dam 2. Preliminary fault trenching investigations discovered a previously unknown, N-NW striking fault that cuts latest Pleistocene alluvium along the east bank of Haiwee Reservoir approximately 2000 feet south of the existing dam. Final fault investigations consisting of geologic/geomorphic mapping, lidar based fault mapping, fault trenching, sonic drilling, cone penetrometer testing (CPT), seismic reflection surveys, and age dating (radiocarbon, OSL and cosmogenic) were done to assess whether Fault A or any other faults represent a surface fault rupture hazard to NHD2. These investigations demonstrated that Fault A is no closer than ~900 feet east of the dam footprint and suggest that the alluvial and bedrock stratigraphy underlying the proposed dam footprint is continuous and unbroken by faulting.