Quantcast
Environmental News for a Healthier Planet and Life

Help Support EcoWatch

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

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

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.

Sustainable t-shirts by Allbirds are made from a new, low-carbon material that uses a mineral extract from discarded snow crab shells. Jerry Buttles / Allbirds

In the age of consumption, sustainability innovations can help shift cultural habits and protect dwindling natural resources. Improvements in source materials, product durability and end-of-life disposal procedures can create consumer products that are better for the Earth throughout their lifecycles. Three recent advancements hope to make a difference.

Read More Show Less

EcoWatch Daily Newsletter

A net-casting ogre-faced spider. CBG Photography Group, Centre for Biodiversity Genomics / CC BY-SA 3.0

Just in time for Halloween, scientists at Cornell University have published some frightening research, especially if you're an insect!

The ghoulishly named ogre-faced spider can "hear" with its legs and use that ability to catch insects flying behind it, the study published in Current Biology Thursday concluded.

"Spiders are sensitive to airborne sound," Cornell professor emeritus Dr. Charles Walcott, who was not involved with the study, told the Cornell Chronicle. "That's the big message really."

The net-casting, ogre-faced spider (Deinopis spinosa) has a unique hunting strategy, as study coauthor Cornell University postdoctoral researcher Jay Stafstrom explained in a video.

They hunt only at night using a special kind of web: an A-shaped frame made from non-sticky silk that supports a fuzzy rectangle that they hold with their front forelegs and use to trap prey.

They do this in two ways. In a maneuver called a "forward strike," they pounce down on prey moving beneath them on the ground. This is enabled by their large eyes — the biggest of any spider. These eyes give them 2,000 times the night vision that we have, Science explained.

But the spiders can also perform a move called the "backward strike," Stafstrom explained, in which they reach their legs behind them and catch insects flying through the air.

"So here comes a flying bug and somehow the spider gets information on the sound direction and its distance. The spiders time the 200-millisecond leap if the fly is within its capture zone – much like an over-the-shoulder catch. The spider gets its prey. They're accurate," coauthor Ronald Hoy, the D & D Joslovitz Merksamer Professor in the Department of Neurobiology and Behavior in the College of Arts and Sciences, told the Cornell Chronicle.

What the researchers wanted to understand was how the spiders could tell what was moving behind them when they have no ears.

It isn't a question of peripheral vision. In a 2016 study, the same team blindfolded the spiders and sent them out to hunt, Science explained. This prevented the spiders from making their forward strikes, but they were still able to catch prey using the backwards strike. The researchers thought the spiders were "hearing" their prey with the sensors on the tips of their legs. All spiders have these sensors, but scientists had previously thought they were only able to detect vibrations through surfaces, not sounds in the air.

To test how well the ogre-faced spiders could actually hear, the researchers conducted a two-part experiment.

First, they inserted electrodes into removed spider legs and into the brains of intact spiders. They put the spiders and the legs into a vibration-proof booth and played sounds from two meters (approximately 6.5 feet) away. The spiders and the legs responded to sounds from 100 hertz to 10,000 hertz.

Next, they played the five sounds that had triggered the biggest response to 25 spiders in the wild and 51 spiders in the lab. More than half the spiders did the "backward strike" move when they heard sounds that have a lower frequency similar to insect wing beats. When the higher frequency sounds were played, the spiders did not move. This suggests the higher frequencies may mimic the sounds of predators like birds.

University of Cincinnati spider behavioral ecologist George Uetz told Science that the results were a "surprise" that indicated science has much to learn about spiders as a whole. Because all spiders have these receptors on their legs, it is possible that all spiders can hear. This theory was first put forward by Walcott 60 years ago, but was dismissed at the time, according to the Cornell Chronicle. But studies of other spiders have turned up further evidence since. A 2016 study found that a kind of jumping spider can pick up sonic vibrations in the air.

"We don't know diddly about spiders," Uetz told Science. "They are much more complex than people ever thought they were."

Learning more provides scientists with an opportunity to study their sensory abilities in order to improve technology like bio-sensors, directional microphones and visual processing algorithms, Stafstrom told CNN.

Hoy agreed.

"The point is any understudied, underappreciated group has fascinating lives, even a yucky spider, and we can learn something from it," he told CNN.

Trending

There are many different CBD oil brands in today's market. But, figuring out which brand is the best and which brand has the strongest oil might feel challenging and confusing. Our simple guide to the strongest CBD oils will point you in the right direction.

Read More Show Less
Financial institutions in New York state will now have to consider the climate-related risks of their planning strategies. Ramy Majouji / WikiMedia Commons

By Brett Wilkins

Regulators in New York state announced Thursday that banks and other financial services companies are expected to plan and prepare for risks posed by the climate crisis.

Read More Show Less
The left image shows the OSIRIS-REx collector head hovering over the Sample Return Capsule (SRC) after the Touch-And-Go Sample Acquisition Mechanism arm moved it into the proper position for capture. The right image shows the collector head secured onto the capture ring in the SRC. NASA / Goddard / University of Arizona / Lockheed Martin

A NASA spacecraft has successfully collected a sample from the Bennu asteroid more than 200 million miles away from Earth. The samples were safely stored and will be preserved for scientists to study after the spacecraft drops them over the Utah desert in 2023, according to the Associated Press (AP).

Read More Show Less

Support Ecowatch