By Alex Laplaza
The rains brought by this winter’s El Niño’s were a welcome reprieve from California’s record-breaking drought. As the deluge of rainfall retreats, the Golden State’s climate is returning to its four-year status quo – hot and dry. For California’s environmental specialists, long known to push the highest regulatory standards in the nation, this winter is anomalous – a blip in a future horizon of declining precipitation and increasing temperatures. Recognition of long-term climate assessments has accelerated the onset of a “new era” of California’s water use.
The drought has hit the Golden State’s two largest cities – Los Angeles and San Diego – particularly hard. In spite of this, or perhaps because of it, Los Angeles and San Diego are leading California’s adaptation to water scarcity, guiding California into a new era water resilience.
California’s Water Challenges
According to NASA’s Earth Observatory, California’s four-year drought has not only been the driest period since record keeping began in 1885, but the hottest as well. Other scientists, using soil-moisture and tree-ring chronologies, have revealed a much longer-term record – the state is undergoing its most severe drought in the last 1,200 years. Furthermore, paleoclimatologists argue that the drought is not as anomalous as the records may seem. Paleoclimatic evidence indicates that drought is a regular feature of California’s and that the past 150 years have been some of the most exceptionally wet in the state’s long-term climate history.
These findings have significant political and infrastructural implications. It was during the “exceptionally wet” 20th century in which most of the state’s water-infrastructure was built. The design of the state’s highly complex system of capturing and moving water (primarily from the wetter north to the drier south) reflects this and is based on abnormally high levels of surface water and precipitation. This further complicates an already tense political challenge of geographic water allocation across the state. Roughly two-thirds of California’s rain falls in its northern regions, but two-thirds of water use by its 39m residents is in its central and southern areas.
The past two years have been watershed years for the state’s water management. In 2014, the California Legislature passed a sweeping groundwater reform law that restricts communities from pumping more groundwater that can be refilled – either naturally or anthropogenically. Then in 2015, for the first time in its history, the state government imposed mandatory water restrictions on urban areas with the aim of achieving a 25 percent reduction below 2013 levels. These drought-induced restrictions are teaching California important lessons on its water supply and use. Los Angeles and San Diego are leading the adaptations.
San Diego: Sea to Sink
In the absence of large groundwater basins, San Diego has historically relied on water transfer agreements with neighboring water districts to supply water to its nearly 1.5 million citizens. San Diego is now turning to another neighbor for its water supply – the ocean. In December, Poseidon Water, a desalination company, opened a $1 billion seawater desalination plant in Carlsbad, San Diego County. The Carlsbad Desalination Project is the largest desalination plant in the Western Hemisphere, producing 50 million gallons of drinking water for over 300,000 San Diegans.
The magnitude of the Carlsbad Desalination Project reflects long-term resilience planning. The plant expects to provide 7 percent of San Diego County’s total water supply – a source that is stable in both wet and dry years. Additionally, the plant’s authorities argue that the plant is relatively secure should a major earthquake damage aqueducts. Successful operation of Poseidon’s Carlsbad Plant would demonstrate that large-scale ocean desalination is feasible in California.
Recognition of this has already led to the proliferation of seawater desalination efforts across California. According to the Pacific Institute, state water authorities have been considering proposals for 15 desalination projects along the California coastline, from the San Francisco Bay Area to San Diego County. If each was built and operated at maximum planned capacity, collectively they could collectively supply up to 62 percent of the state’s non-farm water demand.
This approach is not without its downsides. The technology is energy-intensive, costing consumers about twice as much as conventional sources. Additionally, critics point out that the plant harms marine life and distracts the region’s officials and water managers from efforts to enhance water conservation and recycling.
Los Angeles: Weathering the Storm
Los Angeles is charting a different path from its southern neighbor. The city draws around 88 percent of its water from the Metropolitan Water District (MWD) and the Los Angeles Aqueduct. The remainder comes primarily from its seven local groundwater basins and water recycling. It aims to reduce that figure to 54 percent by 2035 through additional conservation, water recycling, and transfer of water rights from other jurisdictions.
However, Los Angeles is pioneering a new approach: storm water capture. One inch of rainfall on Los Angeles equates to 7.6 billion gallons of water, half of which is lost to storm water runoff into the ocean. The emerging recognition of the potential of storm water capture was reflected in the Los Angeles Department of Water and Power’s storm water master plan, announced in 2015.
The plan provides a framework for cities to plan and build aquifer recharge systems and other forms of green infrastructure. Such systems can capture rainwater before it comes into contact with contaminants and can then be funneled into underground aquifers or spread over fields. Rainwater can also be directed to areas of vegetation or landscaping instead of gutters and sewage systems or stored for later use.
Currently, the city receives an average of 831,000 acre-feet of storm water annually, but is only able to direct 6 percent of it to groundwater reserves. By 2099, the master plan expects to capture 25 to 30 percent of storm water for groundwater recharge and non-potable uses such as sewage and landscaping.
Felicia Marcus, chairwoman of California’s Water Resources Control Board, hailed this effort as “quite historic and path-breaking. Our collective objective should be to use each scarce drop of water, and each local dollar, for multiple local benefits – flood control, water supply, water quality, and urban greening in the face of climate change.”
Southern California’s water resilience will again be tested once this winter’s El Niño’s subsides. However, the Golden State, led by San Diego and Los Angeles, are already heeding crucial lessons on water scarcity and charting a new era of water resilience and adaptation.
For more information, contact Alex Laplaza at email@example.com.