The California State Auditor included aging water infrastructure among its recently released “The California State Auditor’s Updated Assessment of High-Risk Issues Faced by the State and Select State Agencies.”
In the report, the auditor said, “Inadequately maintained dams or those not meeting standards, especially those whose failure could affect large populations, pose significant risks to California residents.”
Data from the California Department of Water Resources indicates “that a majority of dams within the State with less-than-satisfactory condition ratings are in areas where they pose downstream hazard potential (hazard risk) to life or property. Further, the California Governor’s Office of Emergency Services and Water Resources have not yet fully ensured the utilization of precautionary measures meant to prepare dam owners and local entities for potential dam failures.”
State law vests DWR with authority over dams within the state’s jurisdiction, which DWR oversees through its Division of Safety of Dams.
As of October 2019, DWR data indicate 102 dams had condition ratings of fair, poor or unsatisfactory. Of those, 84 had hazard classifications of significant or above, indicating risk to life or property should the dams fail. DWR says there are no state-level programs that provide financial assistance to dam owners for repairing their dams and resolving deficiencies.
According to the report, as of November 2019 about 650 (half) of the state’s 1,250 dams are classified as high or extremely high hazard. State law requires their owners to develop inundation maps and emergency plans. However, 53 owners have failed to submit maps, 285 dams have maps that are pending DWR approval. Of these 285 dams, DWR returned maps to 181 owners for changes. DWR has approved maps for 310 dams. The Office of Emergency Services has received 400 emergency plans. Of these 400 plans received, OES has returned 150 for changes. OES has approved only 22 of the emergency plans it has received.