Quantcast

188,000 Flee as 'Wall of Water' Threatens Northern California

Popular

As nearly 200,000 Northern California residents flee to higher ground over the threat of the Oroville Dam emergency spillway's failure Sunday night, a report has emerged that state and federal officials were warned 12 years ago that the earthen structure was already at risk of erosion.

The Mercury News reported that back in Oct. 2005, Friends of the River, the Sierra Club and the South Yuba Citizens League filed a motion with the Federal Energy Regulatory Commission (FERC) during the Oroville Dam's relicensing process.

The environmental groups said that the dam, which California built and completed in 1968, did not meet modern safety standards and urged FERC to secure the dam's emergency spillway with concrete rather than have it remain as an earthen hillside.

Should extreme rain and flooding occur, the groups warned that the excess water could overwhelm the main concrete spillway and flow into the auxiliary spillway. Too much water could cause heavy erosion and potentially unleash flooding and threaten nearby communities.

"A loss of crest control could not only cause additional damage to project lands and facilities but also cause damages and threaten lives in the protected floodplain downstream," the groups wrote.

However, FERC rejected the groups' request. Furthermore, California's Department of Water Resources and other water agencies that would have paid for the upgrades said the fix was unnecessary.

"It is important to recognize that during a rare event with the emergency spillway flowing at its design capacity, spillway operations would not affect reservoir control or endanger the dam," wrote John Onderdonk, a FERC senior civil engineer in a July 27, 2006 memo to his managers.

"The emergency spillway meets FERC's engineering guidelines for an emergency spillway," he added. "The guidelines specify that during a rare flood event, it is acceptable for the emergency spillway to sustain significant damage."

KQED describes the emergency spillway as "essentially an ungated 1,700-foot-wide notch in the rim of the reservoir ... Below an initial concrete lip, water courses over bare earth all the way to the Feather River below, scouring the incline of earth, rocks and trees."

The secondary spillway has not been needed for use in its 48-year history—until this weekend.

The water level at Lake Oroville, California's second-largest reservoir, rose to record levels of more than a foot above what's considered "full" after Northern California's particularly wet winter. The lake also receives water from the northern Sierra Nevada mountain range, which also saw heavy rainfall, CNN noted.

Although the recent rainfall has brought much-needed relief to California's six years of epic drought, the nation's tallest dam is now nearly full. Water levels at the 770-foot-tall structure were less than seven feet from the top on Friday.

While the Oroville Dam is not currently compromised, both its primary spillway and the emergency spillway have problems due to severe erosion, authorities warned.

The primary spillway has a growing hole that is 250 feet long, 170 feet wide and about 40 to 50 feet deep, according to Bill Croyle, acting director of the Department of Water Resources. Because of the main spillway's damage, water has been pouring into the emergency spillway.

Fortunately, water has stopped pouring over the dam's emergency spillway since Sunday night.

"Oroville lake levels have receded to the point that auxiliary spillway flows have stopped. DWR hopes to push over a million acre feet of water over the main spillway in the next week, clearing the way for much needed flood storage in the lake," California's Department of Water Resources said.

Still, officials are planning for the worst as the situation could yet become dangerous.

"This is not a drill. Repeat this is not a drill," the National Weather Service said Sunday, urging people living near Oroville Dam to evacuate.

A collapse of the secondary spillway could cause a "30-foot wall of water" coming out of Lake Oroville, Cal-Fire incident commander Kevin Lawson said at a Sunday night press conference.

Evacuation orders are unchanged as of Monday morning.

"Once you have damage to a structure like that it's catastrophic," Croyle said. However, he stressed that "the integrity of the dam is not impacted" by the damaged spillway.

California Gov. Jerry Brown has issued an emergency order in response to the situation.

EcoWatch Daily Newsletter

European Commission President Ursula von der Leyen delivers a press statement on the European Green Deal at the EU headquarters in Brussels, Belgium on Dec. 11, 2019. Xinhua / Zheng Huansong via Getty Images

The European Commission introduced a plan to overhaul the bloc's economy to more sustainable, climate-conscious policies and infrastructure, with the goal of being carbon-neutral by 2050, according to CNBC.

Read More Show Less
Young activists shout slogans on stage after Greta Thunberg (not in the picture) took part in the plenary session during the COP25 Climate Conference on Dec. 11 in Madrid, Spain. Pablo Blazquez Dominguez / Getty Images

By Andrea Germanos

Young activists took over and occupied the main stage at the COP25 climate conference in Madrid, Spain Wednesday and demanded world leaders commit to far more ambitious action to address the ecological emergency.

Read More Show Less
Sponsored
A NASA image showing the ozone hole at its maximum extent for 2015. NASA Goddard Space Flight Center

The Montreal Protocol, a 1987 international treaty prohibiting the production of chlorofluorocarbons (CFCs) to save the ozone layer, was the first successful multilateral agreement to successfully slow the rate of global warming, according to new research. Now, experts argue that similar measures may lend hope to the climate crisis.

Read More Show Less
Example of starlings murmuration pictured in Scotland. Tanya Hart / Flickr / CC BY-SA 2.0

Police in Wales are in the midst of an unusual investigation: the sudden death of more than 200 starlings.

Read More Show Less
Donald Trump Jr. killed an argali sheep like this one on a hunting trip in Mongolia. powerofforever/ iStock / Getty Images Plus

During a hunting trip in Mongolia this August, Donald Trump Jr. shot and killed an endangered argali sheep, and received a permit only after the fact.

Read More Show Less