From drought to flood, California cannot seem to get a break. While the multi-year drought may have severely hurt state farmers and strained resident water resources, the current deluges are bringing their own set of challenges to state infrastructure.
Oroville Dam Evacuations
In February, water levels at the Oroville Dam reached their highest level ever following the sudden return of heavy winter storms. This led to the requisite use of the dam’s emergency spillway for the first time in its history. However, soon after use began, officials detected a hole in the structure. That hole swiftly became a crater at the center of the spillway. Officials feared that should the crater destroy the weir, it could cause the unleashing of a 30-foot wall of water. Such a rogue wave would barrel into the Feather River and crash over downstream communities. Due to this threat, officials evacuated over 170,000 residents as crew rushed to resolve the infrastructure issue.
Over the course of two days, engineers and emergency personnel worked around the clock to remedy the issue. They eased the pressure by diverting the overflow to the main spillway and stabilized the area with boulders. Crew members dropped sandbags and other large rocks along the emergency spillway to further protect the base from erosion. However, while officials declared the emergency over on February 14, they cannot begin repair until the end of the rainy season. Furthermore, repair costs are estimated at between $100 and $200 million.
Flood Issues Throughout NorCal
The Oroville Dam may have gotten the most attention in February, but it was in no way an outlier. Heavy storms stressed dams and spillways to and beyond their limits throughout Northern California. An overnight downpour sent water over the Anderson Dam in Santa Clara County and flooding into roadways and low-lying communities.
In the San Joaquin Valley, officials were quickly sizing up the Don Pedro Reservoir during the same period of storms. That dam has an unlined emergency spillway similar to the one that failed at Oroville, making some engineers worry of a repeat failure. Yet while water eventually did gush down over the dam via the emergency spillways, it remained safe and controlled.
The winter storms also threatened much of the region’s roadways and other forms of infrastructure. One frightening example of the devastation possible was the emergence of a 20-foot sinkhole that swallowed two vehicles in Studio City.
One emerging issue here is a lack of attention California leaders have regarding transportation and infrastructure maintenance. According to one former assemblyman, officials have a bad habit of reacting to problems rather than planning how to avoid them altogether. Recent analysis estimates there is a 10-year, $296 billion backlog of needed California road and infrastructure maintenance.