An unprecedented survey has revealed the loss of about 85 percent of historical tidal wetlands in California, Oregon, and Washington. The report, published today in PLOS ONE, also highlights forgotten estuary acreage that might now be targeted for restoration.
Where West Coast rivers reach the sea, estuaries serve as critical nurseries for juvenile salmon and steelhead as they make the transition from freshwater to the ocean.
The California coast grew and prospered during a remarkable moment in history when the sea was at its tamest. But the mighty Pacific, unbeknownst to all, was nearing its final years of a calm but unusual cycle that had lulled dreaming settlers into a false sense of endless summer. Elsewhere, Miami has been drowning, Louisiana shrinking, North Carolina’s beaches disappearing like a time lapse with no ending. While other regions grappled with destructive waves and rising seas, the West Coast for decades was spared by a rare confluence of favorable winds and cooler water. This “sea level rise suppression,” as scientists call it, went largely undetected.
As populations boom and chronic droughts persist, coastal cities like Carlsbad in Southern California have increasingly turned to ocean desalination to supplement a dwindling fresh water supply. Now scientists at the Department of Energy’s Lawrence Berkeley National Laboratory (Berkeley Lab) investigating how to make desalination less expensive have hit on promising design rules for making so-called “thermally responsive” ionic liquids to separate water from salt. Ionic liquids are a liquid salt that binds to water, making them useful in forward osmosis to separate contaminants from water.
Back in 1989, Californians received a sobering warning: The accumulation of heat-trapping gases in the atmosphere would likely bring more droughts, floods, fires and heat waves to the state.
In the 30 years since, those projections of what would happen in a warming world have proven to be remarkably prescient.”We’ve already observed some of the things we expected in 1989,” said Susan Fischer Wilhelm, a research manager at the California Energy Commission, the agency that compiled the report.
Groundwater pumping in the last century has contributed as much as 50 percent to stream flow declines in some U.S. rivers, according to new research led by a University of Arizona hydrologist. The new study has important implications for managing U.S. water resources. Laws regulating the use of groundwater and surface waters differ from state to state. Some Western states, Arizona among them, manage groundwater and surface water separately.
The general long-term forecast for California as climate change intensifies: more frequent droughts, intermittently interrupted by years when big storms bring rain more quickly than the water infrastructure can handle. This bipolar weather will have profound implications for the state’s $50 billion agriculture industry and the elaborate network of reservoirs, canals, and aqueducts that store and distribute water. A system built for irrigation and flood protection must adapt to accommodate more conservation. “The effects of climate change are necessitating wholesale changes in how water is managed in California,” the state Department of Water Resources wrote in a June 2018 white paper.
Water is so commonplace that we often take it for granted. But too much—or too little of it—makes headlines. Catastrophic flooding in the U.S. Midwest this spring has caused billions of dollars in damage and wreaked havoc with crops, after rain tipped off a mass melting of snow. Seven years of California drought so debilitating that it led to water rationing came to a close after a wet and snowy winter capped off several years of slow rebound and replenished the vital mountain snowpack.
Like a climate chameleon, California turned brown during the 2012–16 drought, as vegetation dried or died off. But the change wasn’t uniform. According to research from UCLA and Columbia University, large areas of the northern part of the state were not severely affected, while Southern California became much browner than usual. “Southern California is more prone than the northern part of the state to getting severe droughts,” said UCLA climate scientist Glen MacDonald, one of the paper’s authors. “But that difference seems to be increasing.”
California’s Central Valley aquifer, the major source of groundwater in the region, suffered permanent loss of capacity during the drought experienced in the area from 2012 to 2015. California has been afflicted by a number of droughts in recent decades, including one between 2007 and 2009, and the millennium drought that plagued the state from 2012 to 2015. Due to lack of water resources, the state drew heavily on its underground aquifer reserves during these periods.
The climate is changing, Earth’s population is growing and more people are living in cities. That means urban areas—particularly those in arid or semiarid regions—need to update their water supply systems. The world was reminded of this earlier in the year with the water crisis in Cape Town, South Africa, which has a climate almost identical to that of Los Angeles. At the peak of the crisis, residents were required to limit daily water consumption to 50 liters (about 13 gallons), taking two-minute showers and letting their lawns and gardens dry up.
The Water News Network is San Diego County’s source for water news and information.
