Drought-Stricken Western Districts Plan New Ways to Store Water
(Bloomberg) -- Driving through the Sacramento valley an hour north of California’s capital, most travelers notice nothing but a few cows grazing on grass scorched brown by the heat. But Jerry Brown, the executive director of the Sites Reservoir Project, sees the future of California’s water system.
“I believe scientists are correct and we are going to see wetter wet periods and drier dry spells. California’s current infrastructure is not built for those future conditions,” he said, “But Sites Reservoir is, and that’s why we need it.”
The project, which is still in its design phase, is slated to sit near the Sacramento River and in periods of heavy flooding, it could syphon off some of that extra water and store it for later use. If Sites had been up and running in 2017, California’s last period of flooding, Brown estimates there would now be 1 million extra acre-feet of water to help farmers through the current brutal drought.
This current crisis has emptied massive reservoirs and is reopening a conversation about water storage in the West. Sites is just one of hundreds of new projects being urgently pushed by districts, whose officials see that climate change is irrevocably changing their water equation.
“Our Western water infrastructure is crumbling and insufficient to meet growing water demands and more extreme climate events,” said Daniel G. Keppen, executive director of the Family Farm Alliance, one of 220 agriculture and water management groups that have come together to lobby Congress to spend $49 billion over the next 10 years for repairs for old and crumbing dams, as well as new infrastructure including water recycling and reuse projects.
“The current drought clearly underscores the urgency to expand usable supplies to avoid water curtailments and conflict over water supplies in the future,” he added.
From the early 1900s to the late 1960s, America built mammoth water management projects across the West, including the iconic Hoover Dam. But those projects seem outdated as climate change is altering traditional water cycles radically.
Snowpack used to reliably act as a kind of additional reservoir space for much of the nation, slowly releasing meltwater throughout the year. Now snow is declining and even disappearing in certain altitudes in some years. Meanwhile rains are now arriving earlier in the season and in more concentrated bursts.
Old-fashioned dams on rivers are not handling the change well. In 2017, that last big flood year in California, Oroville Dam nearly collapsed under water pressure and 180,000 residents needed to evacuate. Meanwhile, the state’s Department of Water Resources estimated that 48 million acre-feet of water flowed out under the Golden Gate Bridge, roughly seven times the amount of water exported by the State Water Project annually to meet the agricultural needs of the Central Valley and homes in Southern California.
California passed a law in 2014 that allowed $7.1 billion in bonds for water projects, roughly $2.7 billion for storage specifically. There are currently seven projects under consideration. Water managers are looking to new projects that can absorb the rare intense outflows and store them for the long dry spells in between; the term of art is “water banking.” This means designing reservoirs like Sites that don’t sit on rivers, but adjacent to them, and only fill during moments of intense outflow. It also means pumping water back underground to be stored in natural aquifers which have been drained by overuse. Underground storage replenishes ground water and allows for much less evaporation than its surface counterpart, but it is far more energy intensive.
Southern California is demonstrating the advantages that such investments can bring. Since the early 2000s, water mangers there put more than a billion dollars toward water banking infrastructure, both above- and below-ground. As a result, at the beginning of May, despite the drought ravaging the rest of the state, the area had a record 3.2 million acre-feet of water in reserve.
Such projects take time and lots of money, however, which makes some skeptical as to whether they are really the best way to ease water shortages. David Freyberg, a hydrologist and water resource specialist at Stanford University, is cautious. He argued there is still lots of low-hanging fruit in water conservation—everything from planting crops at different times to changing outdated rules of how dams can function.
“Many dams operate on rules that were put in place when they were built up to 50 or 60 or more years ago when we knew less,” he said. For example, “you often have to release water in the winter to make sure that you have space available for melting snow. But now we don't have as much snow and there's nothing to wait for—but the rules haven’t changed. So we need to better manage our storage.”
California, which has a lot of experience with prolonged drought, is farther ahead of other Western states when it comes to building next-generation water infrastructure, but other states are making progress. Even states that have typically had ample rain have had to wrestle with insufficient water as they try to manage a growing population and also endangered species that require additional water.
Washington state’s Kittitas Reclamation District is one of those areas. It is part of the Yakima River Basin Project, which consists of five reservoirs and was built in the 1930s. It currently waters $4.5 billion in agriculture crops annually and is home to a struggling salmon fishery. A decade ago the various interests in the community were at each other’s throats fighting for water, said Urban Eberhart, who manages the district. But the realization that climate was changing brought everyone together.
“Multiple climate change models showed that in the future, we will not be receiving an orderly melting snowpack,” he said.
So the Yakima community put together a 30-year, $4 billion adaptation strategy that includes everything from raising one local dam three feet to adding groundwater storage and watershed conservation. The dam elevation is under construction now.
But Eberhart says that even before that goes up, they are already lining all the old local canals to make them leak less. And they are using the canals in new ways. In the dry season, they still take water from the basin, but in flood season they now pump it back into the many rivers and streams that have been going dry for a century.
“We’re now rehydrating them,” he said. “We’ve actually been doing this since 2015. It's really new, innovative way of thinking and dealing with climate change.”
©2021 Bloomberg L.P.