Oroville Dam Threatens Valley After Warnings Ignored Long Ago
A Sacramento Bee story published Monday succinctly described the disaster unfolding at the nation’s tallest dam, where flaws in the Oroville Dam’s concrete spillway are forcing water onto the earthen emergency spillway. Threats of a spillway collapse led to mandatory evacuations throughout Butte, Yuba and Sutter counties last Sunday, although residents have since been allowed to return home.
“Oroville Dam contains a flaw, some critics assert, one that could damage the structure during a major flood and threaten downstream communities,” according to the Bee. “That flaw is the dam’s emergency spillway, which empties onto a bare dirt hillside adjacent to the earthen-fill dam.” The torrent of water could erode the unprotected hillside, undermine the emergency spillway’s foundation and lead to a catastrophic failure.
The amazing thing is that the news report was first published Nov. 27, 2005. The Bee‘s Monday publication was a reprint, given the relevance of the report nearly a dozen years later. It provides necessary context after another news organization revealed that three environmental groups at the time had urged state and federal officials to line the emergency spillway with concrete to avoid the kind of problems on display this week.
A dozen years ago, the dam was going through a 50-year relicensing process with the Federal Energy Regulatory Commission. The Friends of the River, the Sierra Club and the South Yuba Citizens League argued in their filings that the 1960s-era dam “did not meet modern safety standards because in the event of extreme rain and flooding, fast-rising water would overwhelm the main concrete spillway”
You can read the rest of this article at: http://reason.com/archives/2017/02/17/oroville-dam-threatens-valley-after-warn