Where does your water come from? Ask many Californians that question, and the most common answers will be the tap or the bottle. Surveys show we know very little about our major sources of water—the Colorado River, the Hetch Hetchy Valley, and especially, the threatened Bay Delta. In advance of a Zócalo/Occidental College event in San Francisco, “How Can San Francisco’s Bay Delta Be Saved?” we asked experts: What is one thing every Californian should know about water (but probably doesn’t)?
Ask a Californian where their water comes from and very few will talk about the complexities of the physical system that brings water to us; fewer still the political complexities that allocate water among competing interests and needs.
Californians can no longer take abundant, healthy water for granted. This is a semi-arid state, contending with the most variable annual precipitation in the nation, population growth, uncertainty of climate change and water systems that are over 100 years old in California. All these are reasons why now is the time to develop new local water supplies through water recycling, greater efficiency with water we already receive, and research and development of ocean-water desalination in the most economically-viable and environmentally-responsible manner.
We must be stewards of this precious natural resource. Use what we have as efficiently as possible, find ways to correct harmful projects, and build new ones with both water supply reliability and environmental benefits in mind. Two examples: 1) the Bay Delta Conservation Plan seeks both to correct environmental problems with the way we move water from north to south across California’s Delta and to improve the sustainability of the Delta’s ecosystem; and 2) West Basin Municipal Water District’s water recycling facility in El Segundo produces 30 million gallons of recycled water every day, conserving enough imported drinking water to meet the needs of 60,000 households for a year within our service area.
Everyone can do their part by conserving at least 20 gallons per day.
There is a range of conservation activities that will help everyone be more efficient with their water use, from turning off the faucet while brushing your teeth or shaving, to replacing turf in your yard with drought-tolerant landscaping. Water recycling and water efficiency are two of the most sustainable actions we can take to protect our planet and our water supplies. We should all be supporting these important water initiatives.
Gloria D. Gray is a Board Member of West Basin Municipal Water District, Metropolitan Water District, and Delta Stewardship Council.
Graham E. Fogg
The decline of the snowpack as source of water storage—and the opportunities, and challenges, associated with replacing that storage
Is there evidence of climate change effects on water resources? Absolutely! California historical data show that for at least the last half-century, the April-July flows in the Sacramento River have declined steadily and can be attributed to a roughly 2-degree Fahrenheit rise in air temperature and the consequently thinner Sierra snowpack that feeds the river.
Total precipitation has not declined, but winter on average is bringing less snow and more rain. Whether future climate change brings more or less precipitation to California, on average more of it will fall as rain rather than snow. This would be fine, except that winter rain runs off and cannot be stored long enough in the surface reservoirs to satisfy peak demands that occur during late spring and summer. So the 8th-ranked economy in the world—and an agricultural sector that provides roughly half of the nation’s fruits, nuts and vegetables—relies on a water system that depends precariously on storage of water from a gradually diminishing snowpack.
Because the diminishing snowpack is in the Sierra Nevada and because the Central Valley floor is the downstream, receiving basin for the mountain snowmelt and runoff, subsurface storage of water in the Central Valley aquifer system will be a key mechanism for storing water in the future. Tantalizingly, because of the over-drafting of groundwater in the Central Valley—home to one of the largest aquifer systems in North America—there is space to store for an additional 10 to 50 million acre-feet of water. For perspective, consider that the combined capacity of our four largest reservoirs (Shasta, Oroville, Trinity, and New Melones) is 13 million acre-feet.
Enhancing storage in Central Valley aquifers, as a way of replacing water now stored in the snowpack is a good idea, but it faces major technical hurdles. First, most aquifer systems absorb water slowly, so moving water from the surface typically requires a place to store the water while smaller quantities are routed to surface spreading basins or injection wells. Secondly, most aquifer systems are mostly not aquifer; in other words, most of the geologic materials in these systems are silts and clays not capable of moving water to production wells. In the Central Valley, most of the material is non-aquifer. And only 20 to 50 percent of the aquifer, depending on where you are, consists of the sands and gravels that can supply significant amounts of water to wells.
The bottom line? The subsurface storage potential in the Central Valley aquifer system is exciting and the technical hurdles are not insurmountable. The first hurdle is to define the subsurface anatomy, or the 3D distribution of aquifer and non-aquifer materials—and then the means and will to manage our subsurface water as effectively as we manage our surface reservoirs would emerge.
Graham E. Fogg is a professor of hydrogeology at UC Davis who teaches courses in groundwater hydrology, groundwater modeling, applied geostatistics, and water resources.
Water shapes landscapes. It transports boulders, cobbles, gravel and sand, carving streams and rivers, building beaches and estuaries. It is both the environment in which aquatic life flourishes, as well as the driver of dynamic processes that create myriad habitats for the diversity of this life.
Water dilutes, concentrates and transports chemical constituents such as salts, nutrients, metals and oxygen through the landscape—and cycles them between subsurface, land surface, and atmosphere. Individual streams are characterized by the timing and magnitude of their floods, the duration of their average flows and the frequency with which they dry. These are just some of the dynamic features of the complex flow regime that influences stream form, ecology, and water quality.
California’s Mediterranean-type climate is rare, occurring in only five regions of the world, and characterized by the strong seasonality and variability of rainfall. Our landscapes, streams, vegetation, and wildlife have been shaped by these unusual patterns of water availability. Wet winters and dry summers lead to alternate flooding and drying extremes. Many streams are intermittent or ephemeral, disconnecting from the ocean during the driest time of the year and providing homes for native species adapted to such conditions. In some areas, snowpack helps to bridge these extremes, but climate change is diminishing this effect. Rainfall variability is high from year-to-year, as well as season-to-season. Winter storms may bring us 16 inches in a month or just 6 inches for the entire year.
Within this complex system, the environmental impacts of water extractions and transfers depend not only on the total volume removed but also on the timing, rate, and location. Decisions toward sustainable use must be workable within the special constraints of our Mediterranean climate and must be built upon comprehensive analyses that address all aspects of water in our environment.
Dr. Felicia Federico is Program Manager for Partnerships and Translational Science at UCLA’s Institute of the Environment and Sustainability. Her research focuses on urban hydrology and policy.
Climate change threatens California’s water supply. Coping will require smart planning, investment, and making conservation a way of life.
Maximum daytime temperatures are increasing almost everywhere in California. Snowpack in the Sierra Nevada—which provides roughly one-third of the water we use—is melting earlier in the spring, leading to reduced water availability later in the year when demand is high.
In the last century, the early spring Sierra Nevada snowpack has decreased by about 10 percent—a loss of enough snowpack storage to fill Folsom Lake one and a half times. By 2050, scientists project a loss of at least 25 percent of the snowpack. This means less water will be available for Californians to use.
Here’s another climate impact: the sea level has risen 7 inches at the Golden Gate over the past century. By 2100, a larger rise—anywhere from 17 to 66 inches—is expected along the California coast, threatening coastal lands and infrastructure, increasing flooding at the mouths of rivers, placing additional stress on levees in the Sacramento-San Joaquin Delta, causing seawater intrusion into freshwater supplies, and intensifying the difficulty of managing the Delta as the heart of the state’s water supply system.
These changes pose serious threats to the economic wellbeing, public health, natural resources, and environment of California. Those of us who work in water resources have an unparalleled interest in anticipating, mitigating, and adapting to these changes. But to succeed, we need Californians to understand the threats and grasp our need to prepare. If we are to succeed, water cannot be the most important issue that Californians never think about.
Mark W. Cowin has worked for the California Department of Water Resources since 1981 and was appointed director by Governor Edmund G. Brown Jr. in April 2012.
It’s the same point every Californian knows about real estate: location, location, location. Location is equally important to Californian’s water in three different but related ways.
The first “location” is the location of where water originates. Most water in the form of rain and snow falls in the north part of the state, and there is great demand to use the water in the south. Though it’s important to develop and rely upon more local supplies and rely less upon the Delta, there is a continued need to move water from where it falls to where it’s needed. But who really needs that water?
That leads to the second location—where you live. We all tend to get locked into thinking about the need for water where we live. We vilify other people, locations, and things; we think they don’t really need or deserve the water. We think those others are “wasting” water. Of course, once you look into water usage, you can see there is room for improvement—greater efficiency, recycling, etc.—in water usage everywhere. We all must contribute.
Finally, there is the “location” that is the chokepoint for much of the State’s water supply: the Delta. The Delta is where water from the north is pumped into canals that move the water south. Plenty of farmers and cities in the Delta also use that water. Fish and wildlife need that water too.
The State Water Resources Control Board’s role in all of this is to determine, via a public process, how to balance the competing uses of water: how to balance the in-Delta water supply needs, with south-of-Delta water supply needs, fish and wildlife needs, and all the other needs for water. More information on the Board’s work can be found at here.
Dorene D’Adamo was appointed to the State Water Resources Control Board by Governor Brown in 2013. She previously served on the California Air Resources Board from 1999-2013 under the Brown, Schwarzenegger, and Davis Administrations, where she was instrumental in the board's air quality and climate change programs and regulations.
The Sacramento-San Joaquin River Delta, or the San Francisco Bay Delta, cannot be saved. The estuary has been inexorably altered by development and climate change is altering it further.
It is possible, however, to mismanage it better.
To do this, everyone drawing from California’s fresh water hub must accept that deliveries cannot be guaranteed. A warming environment will impact how much rain arrives and how long it is suspended as snow in the Sierra. Expensive upgrades to California’s water-moving and storage systems will have to be made—even though none of the billions will guarantee deliveries of more water.
The aspects of the system that are killing migratory Delta fish such as salmon, steelhead, and sturgeon must be addressed, and the devastation of fisheries must be stopped. If National Oceanic and Atmospheric Administration scientists think that investing in twin tunnels under the Delta and a new pumping station north of the Delta will allow water exporters to switch extraction from one station to another as migrating fish pass—and they do—then this is a powerful argument to allow Governor Brown’s signature project to be built.
The wild cards: Who will control the pumps and under what terms?
The quality of the water in the system must be protected. Cities on Delta tributaries such as Stockton and Sacramento must take pollution more seriously.
Meanwhile, water exporters such as the Metropolitan Water District of Southern California and the Westlands Water District must refrain from pointing at pollution and invasive species as the stressors impacting native fish—as if their own massive freshwater withdrawals were blameless.
Jingoism about how America relies on the Central Valley for its fresh fruits, vegetables, and nuts should be retired. Diversification would be good for the country. Farmers on the Delta’s most vulnerable islands should be helped to move.
Can this happen? Yes. Are we capable of it? Perhaps.
Emily Green is publisher and editor of the website Chance of Rain. Previously, she was a staff writer for The Independent and The New Statesman in the U.K. and a staff writer for the Los Angeles Times.
The current manifestation of a “peripheral canal” would move water beneath the Sacramento-San Joaquin Delta in two massive tunnels, aiming to balance restoration of the critically damaged Delta ecosystem with reliable water delivery to farms and cities.
This choice—as with the choices made in each California project over the last century—is complicated by ignorance about the sources of water reaching faucets and by our society’s unwillingness to step away from the old dogma that, “Too much is never enough.”
We do not have to choose the massive and expensive tunnels. A moderate alternative could divert Sacramento River water through a single, shorter tunnel to achieve environmental flows, and include ecosystem restoration and levee improvements that would be less expensive than the current plan while still improving water-delivery reliability.
That should appeal to people in California, especially in southern cities that are weaning themselves entirely from imported water. Every Californian should know these amazing facts:
– Through conservation and highly-treated wastewater, the Water Replenishment District of Southern California (formerly getting most of its supply from the Colorado River) aims for 100 percent reliance on stormwater capture and recycling in the near future.
– The City of Santa Monica plans to eliminate use of imported water sources by 2020.
– Los Angeles aims to cut its purchases of Metropolitan Water District water in half by 2025.
– The cities of San Diego, Long Beach, and Irvine are similarly cutting reliance on imported water.
Water is the essence of life, the key that shapes California’s future. Today, too much is more than enough.
David Carle is the author of Introduction to Water in California (UC Press), Water and the California Dream (Sierra Club Books), and Traveling the 38th Parallel, a Water Line around the World (UC Press).
Water is our most precious natural resource, but it is also one of the biggest threats to our safety. Flooding takes more lives in the U.S. than any other natural disaster. And in California, we are especially at risk.
Every county in California has suffered a major flood disaster within the last 20 years. One in five Californians lives in a flood plain, and more than $580 billion in property and infrastructure is prone to flood. Meanwhile, our flood control systems are aging, and need system-wide modernization to continue serving a growing population. Even if you don’t live in a flood plain you are at risk. Water supply, electricity, highways: all could be compromised for days or even weeks after a major flood.
Government at all levels is making significant progress at reducing our risk through better infrastructure, disaster response and community planning. But one day, a flood is still going to happen. That’s why we must always be prepared. Everyone in California should learn about the flood risk where they live, know what to do in a flood emergency, and buy flood insurance. While we can never completely eliminate the risk of flooding, together we can find better and smarter ways to live with that risk.
Col. Mike Farrell is the commander of the U.S. Army Corps of Engineers Sacramento District.