Nevada keeps emergency response plans for potential dam failures secret for the same reason the U.S. government refuses the state’s demands for information about weapons-grade plutonium shipped to the Las Vegas area: It’s confidential for security purposes, even for dams at golf course ponds.
A two-year investigation by The Associated Press identified at least 1,680 dams nationwide rated high-hazard because of the potential for loss of life if they failed and are considered to be in poor or unsatisfactory condition.
For the 14 such dams in Nevada, the publicly available data suggest none poses an imminent threat or has a safety concern that is not already being addressed. Most are smaller, earthen irrigation dams or retention ponds. Some are empty, two have been decommissioned and three others are headed that way.
But unlike many other states, Nevada will not release the Emergency Action Plans that dam owners are required to update annually so details of potential damage downstream from catastrophic failures are unknown.
Kristen Geddes, the state Division of Water Resources’ hearing section chief, said the reports are confidential because they include information “prepared and maintained for the purpose or preventing or responding to an act of terrorism.”
Idaho is the only other state west of the Rockies that refused to disclose any Emergency Action Plans for the same or similar reasons. Fewer than a dozen states do the same.
Neighboring California makes public a redacted version of its plan for the tallest U.S. dam, the 770-foot-tall Oroville Dam.
Oroville’s 458-page plan covers five associated dams and includes maps identifying communities and highways that could be inundated in a breach of the dam or spillway. It also includes the amount of time authorities would have to alert residents of a failure.
Critics of keeping plans secret include Craig Fugate, former administrator of the Federal Emergency Management Agency who also served as director of Florida’s emergency management division.
“The public has the right to know they live downstream from a vulnerable dam. They have the right to know that they need to be prepared and how they get the warning if there is going to be any,” said Fugate, now chief emergency management officer at One Concern, a company that helps cities and counties create disaster response plans.
AP’s national review is based partly on information in those emergency plans. They indicate thousands of people living and working downstream could be at risk if those dams failed.
Separate inspection reports cite the same problems frequently identified in inspection reports Nevada did provide in response to the AP’s public records requests.
They include leaks that can indicate a dam is failing internally, unrepaired erosion, holes from burrowing animals and extensive tree growth, which can destabilize earthen dams. In some cases, inspectors flagged spillways too small to handle the amount of water that could result from increasingly intense rainstorms due to a changing climate.
The largest high-hazard-poor-quality structure in Nevada is an 83-feet tall dam built southeast of Ely in 1932 at what’s now Cave Lake State Park, a popular fishing and boating destination 30 miles from Utah. It’s one of just three of the 14 potentially problematic dams that are taller than 30 feet.
Few if any seem likely terrorist targets. Two are on a former Sparks golf course closed for years — D’Andrea Ranch Hole #6 Pond and an earthen retention basin that’s currently dry.
The Nevada Department of Wildlife has started drawing down the reservoir at the state park for a projected $3.4 million rehabilitation project of Cave Creek Dam.
A state inspection in June 2018 rated its condition “poor” and warned the potentially undersized spillway may need increased capacity to handle large storms. Inspectors also cited the absence of a low-level outlet necessary to draw down water in an emergency.
The department recently announced new efforts to enhance “the overall stability of the dam,” including spillway expansions and increased storm-water capacity.
Department spokeswoman Ashley Sanchez said the agency has spent nearly $790,000 on analysis, monitoring and design work, but said in an email last month: “We cannot provide you with the Cave Lake Emergency Action Plan due to Homeland Security issues and other safety concerns.”
Department of Conservation and Natural Resources spokeswoman Samantha Thompson said via email that the Nevada dams are safe and that “public safety and well-being is our foremost priority.” But the division can’t release the inundation maps or emergency plans, she said.
Larry A. Larson, senior policy adviser at the Association of State Floodplain Managers, said the Department of Homeland Security “has become an impediment to human safety.”
“If there is a dam failure map produced, it ought to be available so the public can look at it and see whether they are at risk or not,” he said.