美国有线新闻 CNN 灾上加灾 继火灾后美国加州再面临洪灾威胁（在线收听）

We've done some reporting lately on the destructive wildfires in California. The state's still in the midst of its fire season when blazes are more likely to flare up, but the major wildfires we've told you about have been contained for the most part. Now though, some people in Southern California are in danger of another potential disaster — flooding. The U.S. Army Corps of Engineers which operates and maintains about 700 dams in America recently issued a new warning about the Mojave River Dam. It's located at the northern side of the San Bernardino Mountains and last year the Corps ran a risk assessment of it, and concluded that if water flows over the top of the dam during an extreme flood event, the dam could fail.

To be clear, the Corps says the kind of flooding that could cause that is unlikely and it's never happened before. But it's drawing attention to the issue because the area expects more rain this winter. And if the dam were to fail, flooding could effect more than 315,000 people who live in nearby communities about 70 miles northeast of Los Angeles. The Mojave River Dam was built in 1971. That makes it younger than most of the dams across the U.S. There are more than 90,000 of them and most are more than 50 years old. They help provide irrigation and hydropower and protect communities from flooding.

But many across the country are under review and the importance of assessing them became clear in 2017 when the Oroville Dam in northern California was damaged after heavy rainfall. That led to the evacuation of 180,000 people before water levels at the dam dropped. Four years ago the Army Corps of Engineers estimated it would need $24 billion to fix all the dams that needed repairs.