The most recent report on Dams Within Jurisdiction of the State of California lists Oroville Dam as the only one of the dams the California Division of Safety of Dams tracks with an unsatisfactory condition.
The report, just released, gives:
- Dam number, assigned by the DSOD
- National Inventory of Dams identification number
- Dam name
- Latitude and longitude
- Owner name
- Owner type
- Dam height
- Crest length
- Reservoir capacity
- Dam type
- Certified status (certified, certified/Inop or not certified)
- Downstream hazard (low, significant, high or extremely high)
- Condition assessment (satisfactory, fair, poor, unsatisfactory or not rated)
- Reservoir restrictions
- Year built
Of the 1,246 dams listed, only Oroville is considered unsatisfactory. This dam is also considered to be extremely high hazard. (The downstream hazard is based solely on potential downstream impacts to life and property should the dam fail when operating with a full reservoir.)
It is unclear if this means any changes will be made at Oroville, but DSOD says, “If DSOD identifies an issue that presents a significant dam safety concern, it may place restrictions on a reservoir’s operations until deficiencies are corrected.”
Several others were rated in poor condition, including Kelley Hot Spring Fish, Lee Lake, Matilija, Misselbeck, Moccasin Lower, North Fork, Scotia Log Pond, Selvage #2 and Williamson No 1.
Of these, only two are also considered to be extremely high hazard: Matilija and North Fork.
DSOD says this 2018 update reflects several changes, including adjustments to some hazard classifications based on inundation maps submitted by dam owners as required by Senate Bill 92.
Currently under way is a “focused re-evaluation of spillways of 93 dams similar to Oroville,” DSOD says. DSOD is also continuing its efforts on seismic re-evaluations of dams and their appurtenances, which are located near active faults and in densely populated areas.