New Bill Would Toughen Calif. Dam Inspections

DWR Photo: Lake Oroville on Jan. 19, 2018 with lake levels at 707 feet.

A year after the spillway collapse at the Oroville Dam, leading to evacuations of almost 200,000 residents and a beat-the-clock patching job to avoid a break in the tallest dam in the United States, new legislation to strengthen inspections of dams awaits approval of California Gov. Jerry Brown.

The bill would require annual inspections for high hazard dams, raise inspection standards and require consultation with independent experts every 10 years, according to ABC News.

As reported by Risk Management Magazine, problems at the Oroville Dam began when the dam’s main sluice was damaged after a winter season of record rain and snowfall, following five years of drought. Torrential rainfall caused water levels to rise so quickly that large amounts needed to be released to prevent the dam from rupturing and sending a wall of water to the communities below.

A recent report of the root-cause of the spillway failure by the Independent Forensic Team (IFC), which includes members of the Association of State Dam Safety Officials and the United States Society of Dams, notes that:

There was no single root cause of the Oroville Dam spillway incident, nor was there a simple chain of events that led to the failure of the service spillway chute slab, the subsequent overtopping of the emergency spillway crest structure, and the necessity of the evacuation order. Rather, the incident was caused by a complex interaction of relatively common physical, human, organizational, and industry factors, starting with the design of the project and continuing until the incident. The physical factors can be placed into two general categories:

  • Inherent vulnerabilities in the spillway designs and as-constructed conditions, and subsequent chute slab deterioration

  • Poor spillway foundation conditions in some locations

The IFC report concludes that all dam owners in the state need to “reassess current procedures” in light of its findings.

According to the IFC:

“The fact that this incident happened to the owner of the tallest dam in the United States, under regulation of a federal agency, with repeated evaluation by reputable outside consultants, in a state with the leading dam safety regulatory program, is a wake-up call for everyone involved in dam safety. Challenging current assumptions on what constitutes ‘best practice’ in our industry is overdue.”

Initial response to the spillway failure included erosion mitigation for both spillways during the incident, sediment removal and installation of temporary transmission lines at a cost of $160 million, According to the DWR. Phase-two includes removal of the original 730 feet of the upper chute, replacing it with structural concrete.

Calif. Debris Removal Presents Health, Environmental Risks

Last week, Santa Barbara, California suffered 20 casualties, countless injuries and millions of dollars in property damage due to the unprecedented mudslides that tore through the city of Montecito. Search and rescue efforts continue in the aftermath of the phenomenon, which was caused by the heavy rains washing away ground laid bare by the Thomas Fire in December 2017. The resulting millions of pounds of debris left behind present biological and environmental risks to the area. Returning residents have been warned to protect against potentially hazardous chemicals and untreated sewage that were swept along with the mudslide debris. Meanwhile, where all this mud and debris will be moved to presents another dilemma.

Public Health Advisory
On Jan. 17, Santa Barbara County’s Public Health Department issued a public health advisory to warn about potential health conditions residents and workers may face as they return to their homes and businesses. The advisory states that “unknown amounts of potentially hazardous chemicals and untreated sewage were swept into the mudslide debris that flowed through impacted areas,” and provided tips for those affected to protect their health amid cleanup and recovery.

The advisory warned that residents also are at risk of wound infections, rashes, illnesses borne from raw sewage mixing into the debris and immersion foot syndrome (also known as “trench foot”), among other injuries.

Although it was encouraged to leave cleanups to professionals, the Health Department recommended Tetanus shots for those engaged in cleanup activities who have not been vaccinated during the past 10 years. It also acknowledged that while the hepatitis A virus could theoretically be spread via exposure to feces or raw sewage, it had not received any reports of that scenario and maintained the probability is low.

Removal Efforts
Temporary solutions for moving and storing the debris are reportedly in place. According to the Los Angeles Times, dump trucks “discarded at least 3,500 tons—or about 7 million pounds—of muck at the Ventura County Fairgrounds, where it will be stored temporarily until crews can sort through it.”

The Times continued:

Up to 1,000 tons more—per day—could eventually make it down to the Calabasas Landfill. To help with cleanup efforts, the Los Angeles County Board of Supervisors on Tuesday passed a temporary waiver to allow the intake through mid-April.

Santa Paula Materials, which sells rocks and recycled construction debris, will collect the rocks that are hauled out, while Standard Industries, a building material manufacturer, will take the metal and tires, said Lance Klug, spokesman for the California Department of Resources Recycling and Recovery’s Office of Emergency Services.

Wildfire Cleanup Ongoing
The mudslide debris removal compounds the already daunting task of clearing Thomas wildfire debris in other areas. On Jan. 12, the California Governor’s Office of Emergency Services (Cal OES) announced that its cleanup program had moved nearly 1 million tons from the burn scarred areas and had completed work in Yuba, Butte, Nevada and Lake Counties, but “still had much work to be done.” The Environmental Chemical Corporation will continue the massive undertaking of debris clean-up in Sonoma, Napa and Mendocino Counties that were hard-hit during the October 2017 wildfire siege.

The Better Business Bureau issued guidelines for removing both wildfire and mud debris, classifying it into four main categories and recommending disposal in the following ways:

  • Branches, trees and vegetative wastes​ can be separated from the other debris and later can be sent to the community burn pile. These wastes can also be sent to a permitted disposal site.
  • Construction debris​. The structural materials from houses and buildings—such as concrete, boards, shingles, windows, siding and pipes—can be taken to the closest construction and demolition landfill or a permitted municipal solid waste landfill.
  • Other household wastes, ​such as trash and furniture, should be sent to a permitted municipal landfill.
  • Hazardous wastes​. If you believe the waste contains regulated hazardous materials, more care and caution is needed. These wastes should be containerized, labeled, and ultimately sent to a facility that is permitted to store, treat or dispose of hazardous wastes. In these instances, it is important to contact the department to discuss proper disposal procedures.

The guidelines also provide a full list of items that require special disposal, including pool chemicals, tires and commercial and medical waste.

Calif. Mudslides Leave 15 Dead

Heavy rains in southern California have caused mudslides in some areas, killing at least 15 people and trapping hundreds. The deluge of mud now covering homes, businesses and freeways are the result of heavy rains washing away ground laid bare by the Thomas Fire—the state’s largest wildfire to-date—which burned more than 280,000 acres in December.
Many of those who had returned home after the wildfires have been evacuated for mudslides. The New York Times wrote:

As the mud rushed into lower-lying neighborhoods in Montecito, a wealthy hillside community where many celebrities have homes, the power went out and gas lines were severed, said Thomas Tighe, a resident. Officials said Tuesday night that it could be several days before gas service would be restored. They also said power failures were affecting more than 6,000 homes and businesses in the area, adding that many parts of Montecito were without drinkable water.

Driving rain started at about 3:00 a.m. on Jan. 9. By Tuesday, more than 5.5 inches of rain had fallen in parts of Ventura County, the National Weather Service said.  A mandatory evacuation order for about 7,000 residents was issued by Santa Barbara County officials, but many would not leave. As a result, people were trapped in homes and cars and on rooftops by fast-moving rivers of thick mud carrying trees and debris.
CNN reported that dozens of people have been rescued in Santa Barbara County, including a 14-year-old girl trapped beneath a house, and that parts of US 101 in Santa Barbara and Montecito have been closed.

Mudslides are not uncommon in the area, especially following wildfires, and they can be deadly. In January 2005, a landslide struck La Conchita in Ventura County, killing 10 people.

2017 Storms Break Records

The 2017 hurricane season is finally behind us, but it left its mark with two Category 5 hurricanes and one Category 4 striking within weeks of each other, causing an estimated $300 billion in damage. In fact, 2017 broke records, including the strongest storm—Irma—and the longest-lasting storm, which was Hurricane Harvey. Other natural disasters in 2017 also did their share of damage, including hailstorms and 1,496 tornadoes compared to an average of 1,202.

Then there were the wildfires, which burned more than 9 million acres of land.

Highlights of 2017 are summarized below by Interstate: