By Faith Kearns Government, Notes from the Field, Science, Science & Medicine
Drought has gripped much of the western U.S. this year, with a particular stranglehold in California. In 2014, the majority of the state was classified as experiencing “extreme” to “exceptional” drought. Even recent large storms, while welcome, have not made much of a dent in the state’s water deficit after several hot, dry years. This drought, ongoing for three years and counting, presents several complex, important issues:
- Reliance on Snowpack: California’s current water infrastructure depends largely on snowpack. But this dependency will pose significant challenges in the future. Unlike the majority of the U.S., California has a Mediterranean climate with wet winters and dry summers. It uses the Sierra mountains as a natural reservoir: The snow gathers there during the wet season and continually melts during the warmer months, supplying much of the state with water during the summers. If there isn’t an adequate amount of snowpack, water storage and delivery will become huge issues. Even with recent rains, many of the reservoirs continue to hover at low levels.
- Climate Variability: We are learning more about California’s climate from paleoclimate research (the study of past climates). For example, Lynn Ingram at the University of California, Berkeley found that the state previously experienced periods of prolonged drought. Professor Ingram’s research suggests that we may be entering another period of dryness, the likes of which has not been seen in at least 500 years. Her research also shows that some portions of the state have undergone droughts that lasted decades. In fact, the last 150 years or so have likely been some of the wettest in California’s history. And it’s in that time period that most of our large dams (and other water infrastructure) was built. More recently, scientists Daniel Griffin and Kevin Anchukaitis used soil moisture to measure drought. They found the 2011-2014 period to be the driest on record in about 1200 years. These paleoclimate studies are helping us understand California’s highly variable climate, which can help guide water management efforts. Predicting how long this drought will last, however, remains a challenge.
- Climate Change: In addition to climate variability, all signs indicate that global climate change is exacerbating the drought. While it’s difficult to tease out cause and effect, we do know that we are seeing less snow in the mountains and less fog in the Central Valley. We are also seeing fewer big winter storms, which we rely on for our year-round water supply. In addition, 2014 is almost certain to go down as California’s hottest on record, complicating the already dry conditions. For example, Griffin and Anchukaita (cited above) found that California’s reduced precipitation has been compounded by increased temperatures.
- Groundwater Usage: In 2014, the agricultural community relied quite heavily on groundwater to get through the drought. They turned to groundwater because surface water allocations were greatly reduced. Many farmers pumped groundwater from old wells, dug their wells deeper, or created new wells. Research from UC Davis estimated agricultural economic losses due to the drought to be around $2 billion. These losses would have been much, much higher without groundwater. A long-term look at groundwater depletion led by Jay Famiglietti, a scientist at the University of California, Irvine and NASA, found that high levels of long-term groundwater depletion has caused land to sink in agriculturally intensive areas, such as the Central Valley. Homeowners in these areas have seen their residential wells run dry. Unable to afford digging deeper, they’ve replaced well water with trucked in or bottled water.
- Effects on People and Animals: Not only is California the most populous state in the U.S., it’s also home to Central Valley, a major supplier of the world’s food. Both city-dwellers and farmers are trying to find ways to conserve. Farmers continue to work on more efficient methods of irrigation, and urban residents are being encouraged to reduce the amount water used on landscaping, which typically accounts for 50% or more of household water usage. In addition, some areas of the state where people have been the hardest hit are also the poorest, creating cumulative stressors and threatening livelihoods. Furthermore, wildlife and ecosystems have been severely impacted by the drought. For example, the endemic Coho salmon is on the brink of extinction and tricolored blackbirds have just been listed as an endangered species.
How can California even start to cope with its drought? How can it become resilient to future droughts in an arid climate? The oft-repeated phrase that crisis is an opportunity has a ring of truth to it. Although the issues are complex, there have been some achievements: This year has seen quite a bit of movement—political and otherwise—toward developing more resilient water supplies.
- Groundwater Legislation: Earlier this year, Governor Jerry Brown signed legislation mandating “sustainable groundwater management,” though the law leaves local entities to define that idea further. While some local agencies have been managing groundwater at a regional level for some time, this will be the first coordinated, statewide effort. However, even in groundwater basins that the state has deemed high- or medium-priority areas, it will take time to establish the agencies responsible for groundwater management. They will then have until 2020 or 2022 to develop a groundwater sustainability plan, and the plan will just be the beginning of the management process.
- Spending on Water Projects: This November, Californians voted to pass a $7.5 billion water bond that will fund a variety of projects. Over a third of that bond has been allocated for water storage. The specifics of the bond spending were left quite vague. The law notes only that the funds will go to a mixture of surface storage (e.g., dams) and groundwater storage (e.g., managed aquifer recharge). Like the groundwater legislation, the water bond projects may take years—even decades—to be implemented. Research and community input will be needed to understand which projects make the most sense and to decide where they should go.
- Water Independence: Over the last decade, particularly in southern California, there has been a growing focus on “water independence.” Instead of relying on water transfers from wetter parts of the state, major urban centers such as Los Angeles and San Diego have worked to invest in water that can be supplied locally. Los Angeles, for example, is rethinking how to use storm water. The water that used to clog up the drainage system during large storms is now considered a resource, harnessed through the use of permeable pavements and rain gardens, which help to recharge groundwater after a storm.
- Adapting to Variable Water Supply: Due to the growing recognition of how variable our climate is, researchers, growers, and communities are looking toward more resilient approaches to managing water. For example, the state has developed an adaptation strategy for water, which stresses the importance of efficiency in the urban and agricultural sectors, advances the concept of integrated regional water management, and focuses on improving water and flood management systems.
- Community Awareness and Support: People are banding together to support each other through this drought. The state’s universities have been holding workshops and offering training opportunities for communities hit hard by drought, agriculture and ranching. People are starting to realize the scale of change necessary and are joining together in non-traditional alliances. Journalist Brett Walton noted that the success of a water recycling effort in Southern California over the last 20 years was not just a technological feat, but a testament to human partnership.
The million dollar question now is how wet 2015 will be. Most predictions are pretty dire. There were hopes that the El Nino weather pattern might pull us out of the drought, but they seem to be fading. Even in the midst of a series of storms, state water managers note that we would need 150 percent of our average precipitation to recover from the drought. Long-range weather predictions are notoriously tricky. Although we hope for rain, we are actively planning for another dry year, as we should be.