Oroville’s shortcomings highlight the need for municipalities nationwide to look to their infrastructure to ensure it is modern, upgraded and meets the demands of this century, not the year it was built
By Sergio Flores
Several of today’s infrastructure projects are not built to meet the needs of the 21st century. A perfect example that made national headlines in February is the Oroville Dam in Oroville, Calif. After heavy rainstorms, the reservoir found itself at capacity, with excess water being sent out over the primary spillway and down the Feather River. The California Department of Water Resources spotted a crater forming in the spillway, but the dam was still considered to be stable.
Then the situation worsened.
Water flowing at roughly 100,000 cubic feet per second (that’s about the same as Niagara Falls) continued to pour out. The bottom half of the concrete chute crumbled, sending debris into the river. For the first time ever, DWR issued the use of another emergency spillway. The water continued to flow directly onto the earthen hillside well below the emergency spillway. Although this was very much per design, headward erosion of the emergency spillway still threatened to undermine and collapse the concrete weir. As a precaution, nearly 200,000 individuals were evacuated from their Feather River Basin homes. If the secondary spillway had collapsed, it would have caused a massive flood down the river and into the valley – professionals estimated a 30 foot wave of pure destruction.
Fortunately for everyone, this didn’t occur, however, the Oroville Dam serves as a testament to how neglected our infrastructure is. Much talk seems to be centered on building new infrastructure, and although that is very much needed, it would be irresponsible to neglect our already existing infrastructure. Whether it needs to be completely demolished and rebuilt, or simply upgraded to meet the needs of today, it is imperative that we address this to avoid future disasters. So what exactly happened and could there have been upgrades or changes to the dam to prevent this?
For starters, 2016-2017 was reported that wettest winter in over 100 years for Northern California. By mid-February sheriff of Butte County lifted the mandatory evacuation order and everyone returned. One forensics team found an absence of protection against erosion downstream that could have potentially been a factor. Their guess is that heavily erosive rock and soil could have lead to headcutting, abrupt erosion which consequently leads to a ravine. But this is just one of the 24 potential causes for the spillway’s compromise. The report was addressed to Paul Dunlap, a DWR engineer, and will be used to address the repair.
Robert Bea, a former engineer with the U.S. Army Corps of Engineers and UC Berkeley professor, conducted a similar 78-page report for the DWR to consider. He highlighted problems such as clogged drains and damage between the concrete slabs. The major difference between Bea’s report and the forensics team is that the latter focus on technical causes and engineering mechanics, but neglected possible human and organization factors, which Bea believes might have played an important role that definitely should be addressed in its fixing.