Unexpected Playa Geohazards Create Issues for Solar Facility-Video

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A 400-acre solar facility on a dry lake bed south of Las Vegas experienced recurring ground fissures in 2016, 2017, and 2022. The latest event extended thousands of feet, reached depths of 25–30 feet, and damaged panel foundations, equipment, and site access. Investigations suggested the fissures reflect re-exposed buried channels or basin-scale shrinkage and subsidence; rainfall and surface-water flow appear to trigger their growth, while groundwater withdrawal was ruled out. Because conventional subsurface testing across the large site was impractical, the team used MASW geophysics to identify known and possible hidden fissures. A detailed hydraulic model then guided drainage improvements, using access roads as shallow conveyance channels to redirect water away from vulnerable areas. Fissures were filled with cement slurry at depth and granular material near the surface, restoring access and supporting the panels. In discussion, the presenter said site grading likely did not cause the fissures.

Keywords

solar facility

ground fissures

dry lake bed

MASW geophysics

hydraulic model

drainage improvements