Nevada's Aging Dams Face New Earthquake Risks Amid Climate Challenges and Drought

As Nevada grapples with a multitude of environmental stresses, including drought and climate change, the threat posed by earthquakes is being revisited. Although seismic activity has largely been a background concern for many residents, recent earthquake events have underscored the vulnerabilities of the state’s aging dam infrastructure. The state oversees more than 600 dams, with nearly a quarter classified as high hazard, meaning their failure could pose a threat to life and property. The recent seismic activity began with a significant 7.0 magnitude earthquake off the coast of California on December 5, which sent ripples across Nevada, notably impacting the rare Devil's Hole pupfish habitat in Death Valley National Park. Just days later, a 5.8 magnitude quake rattled the Yerington area, causing minor disruptions but serving as a stark reminder of Nevada's geological realities. Although no serious damage was reported, state officials and seismologists are keenly aware that the consequences could be dire if such events occurred closer to urban centers like Las Vegas or Reno. Christie Rowe, director of the Nevada Seismological Laboratory, emphasizes that while Nevada has not experienced a significant earthquake in a populated area for decades, the potential for one remains. With the state experiencing an average of one magnitude 6 earthquake per year, officials stress the importance of preparedness, particularly with infrastructure that has not kept pace with modern engineering standards. One primary focus is the Marlette Lake Dam, one of the oldest in the state, which has recently received federal funding for upgrades. This earthen dam, constructed over 150 years ago, is critical as it serves as a water source for multiple Northern Nevada communities. Given its age and the high seismic activity in the region, the dam has been classified as a "high hazard dam," with inspections revealing a substantial risk of failure in the event of a significant earthquake. A breach could not only flood nearby highways but also threaten the water quality of Lake Tahoe, a vital recreational and environmental resource. Keith Conrad, chief of dam safety at Nevada's Division of Water Resources, notes that the recent federal support for the Marlette Lake Dam retrofit is essential for mitigating risk. "If they know that dam is vulnerable, I'm really glad they're doing preventative work," Rowe said. "It's going to be way less expensive than if the dam failed." This proactive approach is critical given the aging infrastructure across Nevada, where most dams were built before comprehensive state regulations were implemented in 1955. The current landscape of dam safety in Nevada is concerning; a 2018 report from the American Society of Civil Engineers rated the state's dams a "D+" overall, indicating they are "At Risk." Furthermore, a 2023 report by the National Inventory of Dams confirmed that many of these structures are in fair to poor condition. Nearly a quarter of the dams monitored by the state are classified as high hazard, primarily in the Reno/Tahoe and Las Vegas areas. While the focus on earthquake preparedness is crucial, it is also significant to acknowledge Nevada's historical context. The state has seen its share of dam failures in the past, with notable incidents in 1876 and 1955 leading to substantial flooding and loss of life. Although there has never been a federal emergency declaration in Nevada due to dam failure, the potential for disaster looms as the state's infrastructure ages and seismic risks persist. In response to these challenges, Nevada's Division of Water Resources has begun drafting emergency action plans for all high and significant hazard dams, and has activated these plans on several occasions when signs of distress have been noted. These efforts, combined with federal support for critical upgrades, represent a vital step toward ensuring the safety and resilience of Nevada's water infrastructure. As climate change, drought, and the potential for earthquakes continue to threaten life and infrastructure, the state must remain vigilant. The Marlette Lake Dam retrofit is just one example of the necessary actions being taken to fortify against future risks, but it highlights a broader need for comprehensive assessments and enhancements to dam safety statewide. Nevadans may often overlook earthquakes, but as the recent tremors remind us, vigilance and proactive measures are essential in safeguarding communities from potential disasters lurking beneath the surface.