Infrastructure Past, Present, and Future Casebook/Oroville Dam

This casebook is a case study on the Oroville Dam Failure by Matthew Glaubke, Davis Kaderli and Ian Gates as part of the Infrastructure Past, Present and Future: GOVT 490-003 (Synthesis Seminar for Policy & Government) / CEIE 499-002 (Special Topics in Civil Engineering) Spring 2023 course at George Mason University's Schar School of Policy and Government and the Volgenau School of Engineering Sid and Reva Dewberry Department of Civil, Environmental, and Infrastructure Engineering. Modeled after the Shinkansen High Speed Rail Casebook. Under the instruction of Professor Jonathan Gifford.

Summary

Just 70 miles above Sacramento, this earth fill dam is located where the three forks of the Feather River meet. The dam is the tallest dam in the United States and is also the largest water storage and delivery system that is state-owned. It includes a spillway system for runoff water from connecting bodies of water that connect to it. It is owned by the California Department of Water Resources. It is an important factor for the California State Water project. Water that is stored in the dam flows down the river and goes into the Sacramento river system. The dam creates a reservoir that holds around 3.5 million acre-feet of water. It features a fish barrier dam and pool.

The Oroville Dam also protects the residents who are located downstream from possible flooding of the Feather river. One of the most critical aspects of the dam is its role in helping the California water system combat droughts that occur. Because of these functions, the dam is extremely important for Northern California.

What is an earth fill dam and spillway system?

An earth fill dam is made up of compressed earth. Local soil is the main material used for it. Most of these dams contain a middle zone called the core. This zone is made up of low-permeable material. These clayey soils in the core help prevent water from passing through the dam.

They are the most common type of dam that can be built to any height. They are created as a non-overflow section with a separate spillway. They are the most common because of their foundation requirements, which are not as extensive as other dams. Also, high-skilled labor is not required to construct it.

A dam spillway system is a structure that forms part of the dam. Sometimes they are found just beside one. Their purpose is to allow floodwater to safely flow through the dam when a reservoir is full. It is located at a lower height than the rest of the dam. This allows for the water to flow down from the dam onto the spillway.

Institutions and actors involved

There were multiple entities that were responsible for the collapse of Oroville Dam. They collectively work together to monitor the dam and provide maintenance and risk information.

California Department of Water Resources:

The California Department of Water Resources (CDWR) is responsible for the regulation and management of California’s water usage and supply. It manages the water chain of 750,000 acres of California farmland and provides water to California cities and industries. It also helps with flood control, recreational opportunities, hydroelectric power generation, and enhancements that help protect fish and wildlife ecosystems. The DWR’s oversight runs from Northern California to Southern California. In its scope, it oversees 36 storage facilities, 21 dumping plants, 5 hydroelectric plants, and 4 pumping-generation plants.

They have a large number of responsibilities. They oversee the process that updates and develops the California Water Bulletin. They are in charge of regulating dams, providing flood protection, and helping with emergency management. They work to keep California dams safe and up to date. The agency has oversight of the Oroville Dam.

Federal Energy Regulatory Commission:

The Federal Energy Regulatory Commission (FERC) is the federal agency that regulates and oversees electricity, natural gas, and oil. This involves the regulation of wholesale electricity sales and transmission of electricity for interstate commerce. They reinforce mandatory reliability standards for the state power systems.

One of the commission’s main authorities is its oversight of all hydroelectric power projects. One of the main functions of the commission is maintaining dam safety. They conduct security inspections, monitor infrastructure for environmental concerns, and enforce dam safety. They also are in charge of issuing new permits and licensing for new hydropower projects. The commission consults with federal and state natural resources agencies and state water quality agencies before starting new projects. 

The Federal Energy Regulatory Commission regulates the construction and operational phases of new hydropower projects. The commission reviews and approves the designs, specifications, and plans of powerhouses, dams, and other infrastructure. Staff engineers inspect the projects on a regular basis so that they are kept up to date.

Federal Emergency Management Agency:

The Federal Emergency Management Agency (FEMA) acts as the primary point of contact for disaster recovery preparedness for states. They establish and maintain networks for disaster recovery resources and support systems. They also put in place recovery progress plans and communicate improvements to authorities after a disaster. They work with the National Dam Safety Program to strengthen and develop tools to assist decision-makers.

Division of Safety of Dams:

Aside from the DWR, the California water code also assigns dam safety regulatory power to the Division of Safety of Dams (DSOD). They provide supervision for the design, construction, and maintenance of over 1000 dams in California. The agency reviews and approves dam enlargements, alterations, and repairs to make sure that the structures meet minimum requirements. They inspect dams on a regular basis to confirm that they are safe and functioning.

Friends of the River:

Friends of the River is a California activist organization committed to the environmental preservation of California Rivers and drinking water. It was founded in 1973 and they are now one of California’s leading river conservation organizations. They engage in grass-roots organizing and lobbying to influence policymakers. They have led a variety of successful campaigns that were able to influence dam and river infrastructure.

Funding and Financing

The Oroville Dam is publicly funded by the California Department of Water Resources. The DWC funds flood mitigation, management projects, and invests in dam maintenance measures. The DWC worked with Kiewit Corp to form a contract to repair the damages caused by the accident. The dam was originally financed by the DWR. FEMA has a Public Assistance program that reimburses applicants for project disasters. The program covers up to 75% of the possible costs connected with a federally declared disaster. After the Spillway accident, the Department of Water Resources requested $308 million for reconstruction and emergency response funding from the Federal Management Agency. After initially declining, they sent the funds to the DWC that were able to help with reconstruction. 

Timeline of Dam Construction and Failure

1957: The facilities relating to the dam begin construction

1961: The construction of the dam begins.

Dec. 8, 2016, to Jan. 31, 2017: Lake Oroville bottoms out Dec. 8 at 725-foot elevation and begins rising, but is 175 feet from full. Jan. 13 when the lake is 50 feet from full, the spillway is opened to release 15,000 cubic feet per second. Before Jan. 31, the lake topped 855 feet and releases fluctuate between 12,500 cfs and 20,000 cfs. (13)

Feb. 3-6: Multiple storms cause the DWR to increase releases up to 50,000 cfs. The lake's elevation is 849 feet. (13)

Feb. 7: The spillway releases increase, with a target of 65,000 cfs. However a large hole breaks open in the spillway floor about noon, about midway down, and the releases are stopped. With inflow in excess of 100,000 cfs, Lake Oroville begins to rise rapidly, topping 862 feet.

Feb. 8: With the lake continuing to rise, the DWR conducts test releases through the damaged spillway of 20,000 cfs to see how much erosion occurs. Lake level nears 875 feet with inflow still in excess of 100,000 cfs. With no other option, DWR begins releasing 35,000 cfs down the spillway, recognizing the bottom may wash away.

Feb. 9-10: The spillway releases increased to 65,000 cfs, then scaled back to 55,000 cfs. DWR says inflow has peaked and is declining, saying 55,000 cfs discharge should be enough to keep the emergency spillway from being used. Regardless, the water agency removes trees, rocks, and debris from the slope below the emergency spillway weir. PG&E removes power lines that are crossing the area that is at risk of being flooded if the water tops the emergency spillway weir. Lake level tops 890 feet, 10 feet from full. On Feb. 10 work continues below the emergency spillway weir and the Hyatt Powerplant is turned off as debris accumulates in Diversion Pool at the base of the spillway.

Feb. 11: At about 8 a.m., lake level tops 901 feet and begins spilling over the emergency spillway weir for the first time since the lake was completed in 1968. Main spillway releases continue at 55,000 cfs.

Feb. 12: The lake reaches 902.59 feet at 3 a.m. and begins to decline, but water is still running down the emergency spillway. At noon, DWR describes the situation as “stable.” However, at 3 p.m. a gash erodes into the hillside below the emergency spillway weir and begins cutting back toward the weir, raising the risk of a catastrophic failure that could release in excess of a quarter-million acre-feet of water down the Feather River. Releases down the main spillway are increased to 100,000 cfs to relieve pressure on the weir. Butte County Sheriff Kory Honea orders immediate evacuation, as do sheriffs in Yuba and Sutter counties. All told, in excess of 180,000 people are told to leave their homes.

March 6: Despite repeated requests for information, DWR refuses to say how much has been spent during the emergency. State Assemblyman James Gallagher finally gets an answer: $4.7 million per day, or $100 million during February alone.

April 6: The state Department of Water Resources outlines its plans for repairs and replacement of the Oroville Dam spillway by Nov. 1, with the undamaged top chute as the priority.

April 25: For the first time since the crisis began, members of the state Legislature pepper key water leaders with questions about what happened, what will happen next, and what can be learned from it all. Despite the first legislative grilling, not much new was shared or learned.

April 27: Bill Croyle, the acting DWR director, answers questions and listens during a series of community meetings as residents affected by the spillway debacle step up to a microphone and are heard. A total of seven meetings are completed by May 11.

May 4: The independent board overseeing the repair of the spillway recommends the DWR change its priorities and focus on the damaged bottom chute rather than the top.

April 2, 2019: Water flowed for the first time down the rebuilt spillway. Reconstruction of the main and emergency spillways cost $1.1 billion..

Case Narrative

Completed in 1968, the Oroville Dam is the largest earth-fill dam in the United States. It is a vital part of the California State Water Project, which helps supply over 23 million people with water. After a number of storms in the area, a chunk of concrete in the dam’s spillway eroded and broke away. This caused faster erosion to the rest of the spillway, as well as the ground underneath and around it. The spillway flow had to be increased to prevent the risk of flooding on the dam and river, which provoked the evacuation of over 180,000 downstream residents.

In the aftermath of the failure, the Federal Energy Regulatory Commission conducted an investigation with the help of the Association of State Dam Safety Officials and the United States Society on Dams. The investigation took nine months to complete and concluded with a 584-page report that outlined not just the physical failures of the dam, but the human errors that led to the failure. The first human error was found in the design of the dam itself. Right after construction was completed, engineers noticed cracks in the slab of concrete underneath the spillway, but it was quickly dismissed as an issue that only needed ongoing repairs. The dam was also mischaracterized in multiple safety analyses as in good quality when the foundation was eroding.

The investigation also resulted in the discovery that the owner of the dam, as well as regulators, didn’t pay sufficient attention to the safety of the dam, and most spending on the safety was reactionary instead of preventative. Documents and data were not organized. Employees and engineers often didn’t receive the information they needed. The failure helped inform the rest of the dam industry about what to be aware of and the correct practices in ensuring dam safety.    

Oroville spillway damage

Policy Issues

Following the crisis, then-Governor Jerry Brown had to declare a state of emergency and deploy the National Guard to assist with the evacuation effort. He also activated the State Operations Center to its highest level and requested a Presidential Major Disaster Declaration before announcing new policy proposals to boost dam safety and further protect the state from floods.

One of these announcements was a $437 million investment in “near-term flood control and emergency response actions.” Brown’s second announcement was to begin requiring action plans and flood inundation maps for dams in the state. He then announced an effort to “enhance” California’s dam inspection program before requesting federal action in letters to the US Army Corps of Engineers and Secretaries of Defense, the Interior, and Homeland Security.

FEMA runs the National Dam Safety Program (NDSA) works to promote dam safety nationwide. The High Hazard Potential Dams Program provides $22 million a year to states for dam repairs, including $11 million this year from the Infrastructure Investment and Jobs Act.   Two advisory committees currently oversee dam operations in the United States. FEMA-chaired ICODS (the Interagency Committee on Dam Safety) encourages the development of efficient programs to maintain and improve dam safety nationwide. The National Dam Safety Review Board (NDSRB) sets safety goals and examines the effects of federal policy on dams; an analysis of their operations may be necessary to prevent Oroville disasters in the future.

During the dam rebuild, the California Environmental Quality Act (CEQA) was suspended but NMFS (the National Marine Fisheries Service) tried to slow down the process citing the Endangered Species Act. NFMS requested that inspections and construction only occur at night but Congressman Doug LaMalfa (R-CA) strongly condemned these practices in his letter to then-President Trump regarding the Oroville incident that happened in his district.

In 2019, FEMA approved paying $205 million but not the remaining $306 million needed to rebuild the dam spillway. Since the spillway failed due to poor construction practices, FEMA was not responsible for covering the entire cost. Federal law allows FEMA to reimburse up to 75% of the construction costs but FEMA decided only to cover 40% of the cost. When the State or California announced plans to sue FEMA over this lack of reimbursement, the Trump administration reversed course and covered the additional $300 million

Takeaways

Following the spillway failure, there’s been increased discussion about the state of dams in America. The American Society of Civil Engineers gave dams in the US a ‘D’ in 2017 collectively on their annual infrastructure report card. Another major preventable dam failure occurred in Midland, Michigan in 2020 - raising concerns about the state of dams in America once again

An investigation found that the Oroville spillway failure was caused by a faulty construction process. The main spillway was constructed on “poor quality rock” and the spillway designer had never built a spillway before. Multiple cracks had formed over the years, allowing water to break through on February 7, 2017.    

The US Army Corps of Engineers and Independent Forensic Report both came to the same conclusion that design flaws contributed to this dam failure. The spillway that failed was built on unstable bedrock and the spillway’s efficacy had never been tested.

The California Department of Water Resources (CDWR) was also blamed for the failure, as the department was “significantly overconfident and complacent about the integrity of its State Water Project civil infrastructure, including dams.” The dam structure was weak, as the structure depended on thin concrete anchors that were anchored into bedrock and steel. One expert with the National Academy of Engineering suggested that the culture of the CDWR should either be changed or that the department should clean house. Governor Brown chose not to clean house, so it may take a while for this neglectful culture to change at CDWR.

Even in 2020, a report found that despite hundreds of millions of dollars of repairs, there were still vulnerabilities in the dam:

• Erosion could still flood the Hyatt Powerplant
• Structural issues could prevent operators from opening the gate
• The headworks structure could still fail, releasing uncontrolled amounts of water
• A rare storm could cause a breach
• Internal erosion could still occur near the top of the dam

Additional investments of up to $2 billion must be made to address all of these vulnerabilities.

An image of the Oroville Dam in 2017 immediately following its failure

Climate change was also cited as contributing to the Oroville crisis as well. Atmospheric rivers - the phenomena that drenched Northern California on the day of the dam failure in 2017 - are expected to become more and more common as the globe warms. Dam planners and operators’ mistakes will be exposed further if action is not taken to ensure that the process of building and inspecting dams is more comprehensive.

Discussion Questions

How can disasters like the Orville dam be prevented in the future?

What regulatory measures can be put in place to prevent human error?

How should proper mechanisms be implemented to allow concerns from organizations like Friends of the River to be taken into account for dam safety?