General Questions About Storms

  • Q: What is El Niño?

    El Niño refers to unusually warm ocean temperatures in the Equatorial Pacific that sometimes have consequences for weather around the globe.

    Among these consequences can be increased rainfall across the southern tier of the United States and in Peru. This year, climate experts tell us the strong El Niño conditions in the Pacific Ocean give us higher odds of heavy precipitation this winter, especially in southern and central California.

  • Q: Does El Niño make storms worse?

    Sometimes. Historical weather data shows that there is only a roughly fifty percent chance that an El Niño event actually brings a wetter winter. Unfortunately, due to shifting climate patterns, we cannot even be that sure. Of the seven years since 1950 with stronger El Niño patterns (1958, 1966, 1973, 1983, 1988, 1992, and 1998), three were wet years, one was average and three were dry (with water year 1992 perpetuating a drought). Past years were cooler than the temperatures we are experiencing now which will impact the rain and snow boundary for any storms that materialize this winter.

    With those caveats, officials at the National Oceanic and Atmospheric Administration (NOAA) are reporting temperature and precipitation impacts from El Niño are likely to be seen during the upcoming months. Outlooks generally favor below-average temperatures and above-median precipitation across the southern tier of the United States, and above-average temperatures and below-median precipitation over the northern tier of the United States.

  • Q: How can I learn more about El Niño or winter weather patterns?

    NOAA maintains an El Niño information portal here.

  • Q: Will El Niño help solve California’s drought problems?

    The U.S. Drought Outlook shows some improvement is likely in central and southern California by the end of January, but not drought removal. Significantly, El Niño can also bring warmer weather, which means less snow, which means less water for California.

Questions About Individual Preparation

Questions About Government Preparation

  • Q: What is the state doing to prepare for storms?

    At the state level, we’re always preparing.  Voters passed a $4 billion disaster preparedness and flood control bond in 2006, Proposition 1E, that has allowed the state to help local agencies protect homes and lives from levee failures, flash floods, and mud slides. Proposition 84, also passed by voters in 2006, which included $800 million for flood control. Those bond dollars have gone to hundreds of safeguarding projects such as strengthening the levees that protect Central Valley cities; replacing a 114-year-old dam in Escondido; building stormwater detention basins that improve flood control, create habitat and naturally treat urban runoff; and constructing a five-mile pipeline that will enable Los Angeles County to use stormwater to recharge a groundwater basin.

    Across state government, from the California Department of Fish and Wildlife to Caltrans, we are winterizing by clearing culverts, marshaling heavy equipment, training crews in flood-fighting techniques, and most importantly, working with our local partners as they also prepare for higher-than-average coastal storm surge, debris flows, and flooding.

  • Q: How does California capture rainfall during storms?

    California captures storm runoff by holding it in reservoirs, behind dams, or by allowing it to percolate into groundwater aquifers. Thousands of projects across the state use reservoirs and groundwater recharge to store water. Operators of these projects range from a single landowner to the federal government.

    There are approximately 1,400 dams in California. As of late October 2015, the state’s biggest reservoirs held only about one-third of the water they typically would for this time of year. Shasta Lake, the state’s biggest reservoir, only has 1.4 million acre-feet of water but has a capacity to hold 4.6 million acre-feet of water. Although these major reservoirs have significant space to catch storm runoff and stop downstream flooding. They may not fill to capacity this winter--even with abundant precipitation—which is why continued water conservation is so important.

    Most of the state’s biggest reservoirs are operated by the state and federal governments and exist in canyons where they capture rain runoff and snowmelt draining from the Cascade and Sierra Nevada mountains. Historically, snowpack in these mountain ranges has supplied about a third of the water Californians use each year, but as the climate changes California’s snow pack is at risk and that means less water.   

    Underground aquifers are also an important source of water, but refilling them is a slow process that would take at least several years of above-normal precipitation to recharge groundwater basins that have been drawn down through the past four years of drought. Groundwater typically supplies a third of California’s water supply, but it serves as a heavily-used savings bank when reservoir supplies shrink. Last year, Governor Brown signed historic legislation to strengthen local management and monitoring of groundwater basins most critical to the state’s needs.

    In addition to maintaining California existing reservoirs and improving groundwater management, California is poised to make major new investments in additional water storage, whether through construction of new reservoirs or groundwater banking systems. By an overwhelming majority, California voters passed Proposition 1 in November 2014 that includes $2.7 billion to pay for new water storage projects. The California Water Commission is responsible for awarding funds to eligible projects.

    The state and federal governments are also working to modernize the water conveyance system in the Sacramento-San Joaquin Delta to improve the movement of water across the state. The Delta is home to threatened and endangered wildlife, and large water project pumps often are halted by environmental restrictions, which constrains the movement of water across California. California WaterFix is a state and federal proposal to build three new tunnels to allow for a more natural flow of water, reduce dependence on the existing pumping plants, and safeguard a critical water delivery system from catastrophic failure by earthquake, flood, or levee collapse.