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.