Oroville Dam Flood Claims Filed

Concrete continues to be placed on the lower chute of the Lake Oroville flood control spillway in Butte County, California. Photo taken Aug. 7, 2017, by Dale Kolke/California Department of Water Resources.

California residents in the path of water spilled from the Oroville dam in February had until Aug. 11, six months after the incident, to file claims.

The Mercury News reported that Butte County farmer George Onyett, manager of J.E.M. Farms and Chandon Ranch, filed a $15 million claim, saying that after the flooding in February, about 25 acres of walnut trees were washed away by the Feather River. He said that 1% to 2% of the trees in his walnut orchard were lost and that his land is now “irrecoverable.”

Because of the near-collapse of the Oroville Dam in northern California, communities as far as 100 miles downstream were at risk of flooding. Problems at the dam began when its main water channel, or sluice, was damaged after a winter season of record rain and snowfall after five years of drought. Torrential rainfall caused water levels to rise so quickly that large amounts of water needed to be released to prevent the dam from rupturing and inundating the communities below.

But when the force of the cascading water created a large crater in the main spillway, use of the emergency spillway was required. This safety backup, however, also nearly failed because the dirt spillway, which had never been fortified by concrete, began to erode, increasing the risk of damage to the dam. In anticipation of a possible disaster, almost 200,000 residents living in the shadow of the dam were temporarily evacuated.

Niall McCarthy, an attorney representing the farm, said the spillway crisis was “entirely avoidable.” He pointed to waived concerns about inadequacies of the emergency spillway raised by nonprofit groups in 2005, as well as recently released reports by UC Berkeley Professor Robert Bea, of mismanagement by the state Department of Water Resources, according to the Mercury News.

“There was a certainty of failure with respect to the Oroville Dam,” McCarthy said. “The state chose to make band-aid repairs. The state failed to do its job. (This was) not caused by natural conditions, (but) by human error.”

State officials have maintained it is unclear whether the fluctuation in water releases from Oroville harmed the river and those who farm along it between the shore and major flood protection levees. They argue that some bank erosion would have occurred this year, regardless, given Northern California’s record rainy season, according to the Sacramento Bee.

A number of other business owners and individuals have also filed claims with the state Department of General Services. The Sacramento Bee reported that there were 11 claims at the beginning of July and that there are now a total of 92 claims filed by residents.

A list released by DGS showed claims totaling $1.17 billion. However, that includes a $1 billion claim filed on behalf of “all affected parties” owning land along Northern California rivers where flows were affected by sudden water releases from Oroville. That claim, filed by a Woodland lawyer named James Nolan, added that actual damage amounts aren’t yet available.

Construction efforts at the Oroville Dam spillways are underway and are focused on repairing and reconstructing the gated flood control spillway, also known as the main spillway, by Nov. 1, according to the California Department of Water Resources.

Recap of 2016 Weather Events

The 2016 hurricane season, which ends today, has been the deadliest since 2005 and the most active and costliest since 2012. In all there were 15 named storms and seven hurricanes, three of them major hurricanes. Hurricane Matthew, a Category 5, was responsible for more than 1,600 deaths and insured loss estimates of about $7 billion.

Other major storms that hit the United States in 2016 include Winter Storm Jonas, Louisiana flooding, hailstorms, tornadoes and hurricanes. For a recap of 2016 storms check out Interstate’s year-in-review infographic:
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Houston Faces ‘Largest Flooding Event Since Tropical Storm Allison’

Historic flooding has left the Houston metropolitan area inundated once again this week, killing at least seven people, flooding 1,000 homes and causing more than $5 billion in estimated damages in Harris County alone. Gov. Greg Abbott declared a state of disaster for nine counties in and around the Houston area. The widespread nature of the disaster prompted the city of Houston to call this the largest flood event since Tropical Storm Allison, which devastated southeast Texas in 2001, causing $9 billion in damage and $1.1 billion in insured losses.

According to Harris County Judge Ed Emmett, about 240 billion gallons of rain fell on the Houston area this week. That’s the equivalent of 363,400 Olympic-size swimming pools, CNN reported. After 10 inches of rainfall fell in six hours Sunday night into Monday, powerful, slow-moving thunderstorms had paralyzed the region Monday, but storms continued through Wednesday.

Having some of the hardest rainfall overnight helped a bit to mitigate the dangers this week. While this made it difficult to predict, it allowed people to better make choices about going out, as opposed to last year’s floods around Memorial Day, Emmett told the Houston Chronicle. Nevertheless, emergency crews made more than 1,200 high-water rescues, many residents had to evacuate to shelters, and for those who were able to shelter in place, 123,000 homes had no power at the height of the flooding. Officials have also expressed concern about two local dams that have been rated “extremely high risk and are at about 80% capacity, but they are not in immediate danger of failing.

As I wrote in Risk Management last year, the city’s rapid urbanization and approach to land development have made it extremely vulnerable to flooding perils because there is little land surface that can absorb water in foul weather. Rivers, bayous and other receptacles for runoff are easily overwhelmed and take a considerable amount of time to return to normal levels, making the heavy, concentrated, sustained rainfall seen this week even more dangerous in such an urbanized setting. Last May, record rainfall and severe thunderstorms caused tremendous damage across Texas and Oklahoma, killing 32 people and flooding more than 5,000 homes in the metro regions of Houston, Austin and Dallas.

With this latest storm, Houston again offers a powerful reminder about the natural catastrophe perils compounded by urbanization and the need to prepare, both in the form of routine disaster preparation and urban planning. From the August issue of Risk Management:

The city has invested hundreds of millions of dollars to battle the effects of urbanization. On Buffalo Bayou alone, for example, flood control efforts totaling half a billion dollars in the past decade have included bridge replacements, the addition of detention ponds for runoff, and creation of green spaces that serve as parks in normal weather while offering more land surface that can absorb water in foul weather.

But the investments are not enough. “Houston may be doing things to try to improve…but there’s a long history of pre-existing stuff that is still there,” Walter Peacock, an urban planning professor at Texas A&M and director of the school’s Hazard Reduction and Recovery Center, told Time. “Think about every time you put in a road or a mall and you add concrete—you’ve lost the ability of rain to get into the soil and you’ve lost that permeability. It’s now impermeable, and therefore you get more runoff.”

2015 Extreme Weather Events in Review

From hurricanes to hail to droughts to tornadoes, 2015 was a busy year for extreme weather events. Drought in California continued to worsen, increasing the risk of wildfires. While record rainfall in Texas and Oklahoma alleviated drought, it caused severe flash flooding in Texas. There have been 25 Category 4-5 northern hemisphere tropical cyclones—the most on record to date, breaking the old record of 18 set in 1997 and 2004.

The Insurance Information Institute reported that insured losses from natural disasters in the United States in just the first half of 2015 totaled $12.6 billion—well above the $11.2 billion average in the first halves of 2000 to 2014.

Interstate Restoration provides a look at 2015 weather events:

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