An All-Hazards Threat Guide to California’s Water Supply

California’s water supply is under intense pressure due to the severe drought afflicting much of the western United States. Drought conditions, however, are not the only hazard impacting the state’s water supply. In fact, there are multiple natural and human-related hazards for utilities to consider in their security and resilience planning.

There are many potential natural hazards which could impact a utility’s ability to operate or have adequate source water. For instance, wildfires can significantly harm water supplies. They can burn down storage facilities and damage pipes as well as lead to contaminants in water supplies. Storms and the associated flooding can overwhelm unprepared utilities. Relatedly, rising sea levels could lead to more saltwater seepage into coastal groundwater and increase storm surge flood events. A drought, or low precipitation levels, of course precludes stressed water sources from replenishing. Finally, earthquakes can damage storage tanks and pipes or lead to the release of natural gas or oil into aquifers.

Human-caused hazards are a newer threat, but still potentially as impactful as naturally occurring hazards. Chemical contaminants, from industrial run-off or other sources, are a serious concern for human health and something the EPA is working on addressing. Urban runoff, which mostly occurs after rainstorms, can lead to human introduced pollutants, such as oil, pesticides, and fertilizers, seeping into surface water supplies. Sewage spills may also affect the water supply by introducing contaminants into drinking water sources as well as potentially inducing algae blooms. Finally, security concerns from human threat actors, whether in the physical or cyber domain, is a potential hazard for utilities to consider. In short, there are many hazards that could potentially affect a utility in California. However, many of these hazards identified could impact utilities across the country and the world. By recognizing these hazards, utilities can work towards increase their resilience against these potential future threats. Read more at Cal Matters.