California is ordering immediate spillway inspections at about 70 aging dams that it believes might not be sound enough to protect downstream communities in a flood, a state dam regulator said Wednesday. The engineering and on-site reviews are part of stepped-up inspections following February’s surprise failures of both spillways at California’s 770-foot-high (230-meter-high) Oroville Dam, the nation’s tallest. Authorities ordered nearly 200,000 people to evacuate in that crisis. Since then, regulators at California’s dam-safety division began reviewing their records on the 1,250 dams they monitor, focusing on 100 big, aging dams that have people downstream, supervising engineer Daniel Meyersohn said.

Salton Sea’s creation was nothing but a big accident. In 1905, irrigation canals on the banks of the Colorado River broke, flooding the Salton basin and submerging the town of Salton. By 1907, the canals were fixed, yet, the lake had been already formed. Initially, the new lake was marketed as a “miracle in the desert.” In the 50s and 60s, it attracted over half a million tourists per year. Even Hollywood stars, like the Beach Boys and Sonny Bono would visit regularly.

In light of the crisis at Oroville Dam earlier this year, state regulators have begun ordering up-close inspections of aging dams throughout California. In a letter received by the San Luis Obispo County’s Public Works department on June 12, the chief of California’s Division of Safety of Dams ordered the county’s flood-control district to complete a “comprehensive condition assessment” of the Lopez Dam’s spillway. “We completed a reconnaissance-level assessment of the spillway at Lopez Dam and have noted that structure may have potential geologic, structural, or performance issues that could jeopardize its ability to safely pass a flood event,” the letter stated.

A decade ago, Guy McCaskie would stand on the shore of the Salton Sea and marvel at the vast masses of birds that congregated on the water and flew overhead. Nowadays he looks out over the lake and is saddened by how few birds he sees. Most of the American white pelicans have disappeared. So have most of the double-crested cormorants and eared grebes. McCaskie said these types of birds are vanishing because they can no longer find enough fish or other food in the lake.