Tens of thousands of residents fled Oroville, California, on Sunday after water levels surged over a spillway at the Oroville Dam. Traffic jams reigned on highways leading north from Oroville, where officials ordered people to evacuate at 4:45 p.m.
Oroville families, who made their way to the Silver Dollar Fairgrounds in Chico and other staging areas, face uncertainty in the coming days. By late Sunday night, water from Lake Oroville was no longer rushing over the top of the dam’s emergency spillway, thanks to efforts by California water authorities to increase the flow of water out of the reservoir. But the spillways sustained damage during Sunday’s flooding. Officials are attempting to measure that damage as they consider next steps.
“The dam is solid,” said Bill Croyle, acting director for the California state Department of Water Resources, during a press conference. “The control structure has been damaged.”
The problems started last Tuesday, when a hole opened up in the Oroville Dam’s primary spillway. The collapse in this main, concrete-lined spillway led authorities to take an unprecedented step by the end of the week, as heavy storms mounted. On Saturday, the state water agency made use of the dam’s emergency spillway for the first time ever. The emergency spillway, also described as the auxiliary spillway, is more or less a hill that drains down into the Feather River.
Sunday’s floodwaters proved too much for the emergency spillway. The hill suffered erosion so severe that it threatened to undermine a concrete portion running over the top of the spillway. Its collapse would have sent a “30-foot wall of water” crashing out of the lake reservoir, according to the Los Angeles Times. Had this part of the emergency spillway failed as waters rushed over it, it would have spelled disaster for communities downstream—a threat that prompted Sunday’s evacuation order.
The Department of Water Resources succeeded in tamping down the water levels and saving the emergency spillway by increasing the outflow of the main spillway—despite its giant gash—from 55,000 cubic feet per second to 100,000 cubic feet per second on Sunday. Asking more of the main, compromised flood-control structure, however, was not a decision without risks, especially for the dam’s Hyatt Powerplant.
“It was a tough call to make,” Croyle said. “It was the right call to make to protect the public.”
Croyle said that the agency hopes to drain 1.2 million acre feet of water from the reservoir on Monday and draw down water levels by 50 feet. This will be a tall order, even if the dry weather holds.
The heavy storms in Northern California that precipitated the flooding herald the very beginning of what promises to be a wet season for California. When the snowpack begins to melt, the Oroville Dam’s spillways will need to be in good working order to protect communities downstream. Oroville may have escaped the worst, but the crisis is not yet over. And a near-disaster in Oroville could still augur other crises the U.S. will face if it does not make good on the deferred maintenance costs of its aging infrastructure.
For the more than 100,000 residents who were forced to evacuate their communities, this crisis was long in the making. In 2005, three environmental organizations—the Friends of the River, the South Yuba Citizens League, and the Sierra Club—warned federal officials that the earthen emergency spillway wasn’t capable of handling extreme flooding. But on the recommendation of state officials who balked at the cost of paving the emergency spillway, the feds tabled the matter, The Mercury News reports.
Nationwide, the federal government has invested relatively little in dams and levees. The 2009 stimulus bill provided $290 million for flood-prevention projects and another $490 million for repairing infrastructure projects, including dams, on Native American reservations—drops-in-the-bucket figures given the size of the recovery bill. The federal government spends at least as much on flood recovery as it does on flood prevention.
Just before President Donald Trump’s inauguration, President Barack Obama managed to attach his name to a major water infrastructure spending initiative. In December, Obama signed the Water Infrastructure Improvements for the Nation Act into law, authorizing hundreds of millions of dollars for water infrastructure projects around the country. The bill further enables the U.S. Army Corps of Engineers to pursue certain prescribed projects, including the construction of levees in the Sacramento River floodplain (which entails the Feather River).
One provision under the bill that may pertain to the Oroville Dam is a section that calls on the administrator of the Federal Emergency Management Agency to establish a grant program for identifying and rehabilitating “high hazard potential dams.” FEMA has an enormous opportunity to put this power to use. Of the nation’s 87,359 dams (as of 2013), about 17 percent (14,726 dams) are classified as high hazard potential—meaning that failure would result in loss of human life.
This index only reflects the consequences of dam failure, not the circumstances of dams; so it does not mean that 17 percent of dams are in failing condition. But if any of these dams does fail, the effects are likely to be catastrophic.
The Oroville Dam is working as expected. Even so, the failure of peripheral dam structures—one or both of the spillways—could have disastrous consequences for the economy and environment. State and federal officials across administrations passed on the opportunity to take preventative action to upgrade these structures, improvements that would have cost tens to hundreds of millions of dollars. Now that both spillways have sustained damage, the improvements are instead damage control. The costs to communities are still being tolled.
Upgrading the Oroville Dam spillways isn’t a project that fits neatly into Trump’s $1 trillion prescription for infrastructure spending. So far, Trump’s plan largely means privatizing infrastructure development through the use of tax credits. Armoring the Oroville Dam’s emergency spillway isn’t the kind of investment likely to lure profit-minded private developers.
But this work is absolutely necessary to protect communities near dams—to say nothing of the bridges, water pipes, and other aging systems that serve Americans. If infrastructure investment in the Trump era means widening highways and nothing more, communities will pay dearly once the bill comes due for the projects the government neglects.
CORRECTION: The first photo caption shows water spilling over the damaged primary spillway, not the emergency spillway.