Ten ways the feds can help ease drought in the West

Lake Oroville showing The Enterprise Bridge looking from the South Fork on September 5th, 2014.

South Fork of Lake Oroville, California’s second largest reservoir, on Sept. 5, 2014. Photo by Kelly Grow/California Department of Water Resources

The AuthorsSince the onset of California’s drought emergency 16 months ago, federal agencies and Congress have been seeking to help the state through funding and new and existing legislation.

Here are 10 recommendations for new federal actions. Although many focus on California, they are relevant to other western states facing similar challenges. Because droughts are a recurring — and increasingly likely — feature of the western American climate, we also address water management actions important for longer-term support of a healthy economy, society and environment.

Federal drought support for the near termthefeds

The drought has revealed different challenges in different sectors. (For a summary of drought impacts in California, click here.) Modest federal actions could support drought resilience in each of these sectors, in many cases without additional funds.

Rural communities: Some smaller, rural communities whose wells are running dry because of falling water tables need financial support for alternative sources, such as new wells, pipelines to other systems and, in the short-term, trucked-in water. Relaxation of federal funding rules could help.

(1)  Waive the 15-connection limit for federal support.
Safe Drinking Water State Revolving Funds are available to support such communities, but only if their water systems serve at least 15 connections, the threshold for regulation under the Safe Drinking Water Act. Many California communities rely on smaller systems and domestic wells where these funds cannot be used. Waiving the connection limit would likely be helpful in California and other western states.

Cities and farms: Federal action can lessen the socio-economic impacts of drought in urban and farm areas by enhancing the flexibility of water market and storage operations for federally owned water projects. Easing rules on allocation of federal matching grants could speed the process significantly.

(2)  Allow carry-over storage.
Many federal water projects in the West restrict the ability of contractors to carry reservoir water over into the next water year. For instance, the Central Valley Project (CVP) owns any water that is not taken out of reservoirs by March 1 (with the exception of San Luis Reservoir south of the Delta) [1]. This practice encourages potentially wasteful “use it or lose it” behavior and results in lower reservoir levels. During droughts, the U.S. Bureau of Reclamation should allow carryover. Those storing water for the next year would take on the risk of spillage if late-season rains make it necessary to release water for flood management. To minimize spillage, reservoir operators (including the Army Corps of Engineers) should experiment with real-time forecasts to inform flood releases.

(3)  Facilitate water trading.
Although federal projects such as the CVP accommodate water trading, the authorization process is often so cumbersome that it slows and even prevents trades. Legislation could direct the Secretary of the Interior to facilitate water transfers during drought emergencies and make available any excess infrastructure capacity for this purpose.
 For single-year transfers, legislation could also exempt trades of project water from the National Environmental Protection Act (NEPA), as California does under the California Environmental Quality Act (CEQA). As described below, water users could contribute to an ecosystem restoration fund in exchange for this regulatory flexibility. In California, it would be especially useful for CVP exchange and settlement contractors to develop long-term contingent contracts with more junior contractors, especially those lacking other water sources for permanent crops.

(4)  Facilitate the distribution of federal cost shares for local projects. Both cities and farms can build drought resilience through development of non-traditional water sources, such as capture of recycled wastewater and stormwater. Flexible federal cost-share programs — which allow agencies to directly fund states for certain purposes (for example, capture of recycled water and stormwater, groundwater recharge and smart meters) — would speed distribution of federal matching funds by allowing states to directly apply for them. In California, the federal government could usefully support drought-resiliency projects by directing CALFED funds to cost-share on projects supported by state bond money.

Ecosystems: In California — and elsewhere in the West — more deliberate approaches are needed for environmental stewardship during droughts. This includes actions that safeguard species and help fund these efforts. Federal land and water resources can also contribute to these actions.

(5) Develop and implement a drought biodiversity strategy.
Along with the state, the federal government could support development of a biodiversity plan that guides federal and state actions. The Australians made great strides in ecosystem management by taking this route during their decade-long Millennium Drought. Such a strategy should include:

a.  Identifying aquatic refuges for at-risk species, with an initial focus on public lands for immediate special management; work with NGOs to identify and acquire refuges and water rights on private lands
b.  Identifying investments for conserving cold water, particularly in federal reservoirs
c.  Identifying and buying emergency water supplies for in-stream flows and wildlife refuges
d.  Acquiring water rights for the environment and giving water managers the flexibility to engage in short-term trades of this water
e.  Designating watersheds rich in native species as high priorities for conservation, especially those with spring water sources
f.  Building conservation facilities or repurposing existing hatcheries to rescue fishes whose habitat has disappeared [2]
g. Fostering a “Delta Science Center” for government and academic scientific work on the Sacramento-San Joaquin Delta — similar to federal science efforts for the Chesapeake Bay and the Great Lakes — with objectives that include improvement of the region’s resilience to drought 

(6)  Augment ecosystem restoration funds to build drought resilience.
Mindful of the need for any new federal funding proposal to identify a funding source, we propose the expansion of the ecosystem restoration fund model now used for the CVP. The project charges an ecosystem restoration fee of approximately $10 for irrigation users and $20 for municipal and industrial (M&I) users for each acre-foot of water delivered. During droughts, revenue collection would fall with deliveries, but the government could borrow against future revenues. This fund could also be augmented with a surcharge based on the fixed M&I rate or a percentage of the water price on transfers that use federal facilities or benefit from NEPA exemptions on short-term transfers proposed above. Such a small surcharge would amount to a minor price compared with the costs of water traded during California’s current drought. Finally, when environmental-flow regulations are relaxed during droughts for the benefit of urban and farm water users, those users could be charged for this water — similar to a market transaction — and the proceeds could go to this restoration fund [3].

(7)  Speed the ability for emergency listings of species threatened with extinction.
Numerous species not already listed under the Endangered Species Act are at risk, but the U.S. Fish and Wildlife Service (USFWS) does not have the resources or procedures to list them. Part of the problem is that the agency depends almost entirely on its own in-house work for this purpose, even when scientifically rigorous analyses are available from state fish and wildlife agencies and other sources. USFWS could be required to supplement its own work with studies by other agencies to create emergency listing packages.

Statewide water operations: The federal government can improve the measurement, monitoring and forecasting information needed to manage scarce water resources fairly and efficiently.

(8)  Direct expertise and investments toward information systems.
U.S. Geological Survey and National Weather Service expertise and programs should be reinforced and directed toward (a) helping states improve gauging and modeling for water allocation and use, (b) investments in new technology to improve water-use measurement and accounting — such as metering and satellite remote-sensing for agricultural water use — and (c) groundwater modeling to expedite implementation of California’s new groundwater management law.

Longer-term federal actions for drought resilience

The above actions would work within existing institutional frameworks to improve the capacity of water systems to cope with droughts. As the U.S. Bureau of Reclamation’s study for the Colorado River basin and other studies show [4], water scarcity is expected to become increasingly common in the West. Institutional changes can increase the capacity to support the economy, society and environment.

(9)  Create an Independent System Operator (ISO) for water.
California in particular would benefit from creating an ISO for water — similar to the one for the state’s energy system. This would involve merging the federal and state water projects and operating them as a single public utility, with an ISO overseeing overall grid operations. The federal and state governments could seed the foundation of an ISO by charging it first with facilitating voluntary water marketing [5].

(10)  Promote regional integrated water management. Federal and state governments recognize the value of more coordinated, integrated water management to achieve multiple benefits, such as managing floodplains to simultaneously reduce flood risk, improve habitat and recharge aquifers. But an institutional framework is needed to truly coordinate the actions of the numerous federal, state and local agencies involved in water management. A promising approach is to organize by hydrologic regions or large watersheds. A law similar to the federal Coastal Zone Management Act would empower states to develop integrated watershed plans that federal agencies would then follow. This structure could be useful for more effectively addressing a host of challenges in managing water supply, water quality, drought, floods and ecosystems [6].

California’s drought highlights challenges facing water managers throughout the West. The challenges are likely to increase with a growing population and changing climate. Modest federal investments and policy changes can help reduce the economic, social and environmental impacts of the current drought. These same actions, along with long-term improvements in integrated water management and water trading, can help California and other western states prepare for inevitable future droughts.

For a PDF of this blog, click here.

Notes and further reading

[1] California’s State Water Project allows contractors to carry over their water from the prior year.
[2] A model is the Dexter National Fish Hatchery & Technology Center in New Mexico, the only federal facility dedicated exclusively to the study of threatened and endangered fish. Scientists there perform life history studies and analyze fish genetics while maintaining a refuge for 16 imperiled fish species.
[3] Lund, J., Hanak, E., B. Thompson, B. Gray, J. Mount, K. Jessoe. “Why Give Fish Flows Away for Free During a Drought?” California WaterBlog, Feb. 11, 2014
[4] U.S. Bureau of Reclamation. “Colorado River Basin Water Supply and Demand Study“, December 2012; Diffenbaugh, N.S., Swain, D.L., Touma, D. “Anthropogenic warming has increased drought risk in California,” PNAS 2015 : 1422385112v1-201422385
For a discussion of this idea, see Hanak, et al. “Managing California’s Water: From Conflict to Reconciliation.” Public Policy Institute of California. 2011. Chapter 7.
[6] Hanak et al. “Managing California’s Water: From Conflict to Reconciliation.” Public Policy Institute of California. 2011. Chapter 9; Thompson, B. 2012. “A federal act to promote integrated water management: Is the CZMA a useful model?” Environmental Law: vol 42-1, p. 201-240

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Q & A on survival of California’s delta smelt 

William La Jeunesse and Petr Moyle. PhotoL Fox News and John Stumbos/UC Davis

William La Jeunesse, Los Angeles-based correspondent for Fox News recently interviewed Peter Moyle, UC Davis professor of fish biology, on the survival of the delta smelt  Photo: Fox News and John Stumbos/UC Davis

Four years of severe drought and decades of huge water diversions appears to have pushed delta smelt to the point of no return. State biologists netted only a single smelt last month in trawl of 40 sites in San Francisco Estuary, the species’ only home. The record-low catch came less than a month after UC Davis fish biologist Peter Moyle warned state officials to prepare for the smelt’s extinction in the wild.

Fox News correspondent William La Jeunesse recently spoke with Moyle about the survival of the much politicized tiny fish, a federally designated “threatened” species with protections that at times have curbed the flow of water to many cities and farms. The interview resulted in only 10 seconds of air time. However, the reporter and biologist later agreed to post on California WaterBlog this more insightful series of questions and answers they had drafted in preparation for the interview.

Q.  Given the latest smelt survey, is it fair to say the species can no longer survive on its own?

It is fair to say that most native species in the Delta cannot survive on their own; all require some form of human assistance. Smelt are just leading the pack as the species in greatest need of help. The goal now should be to keep the population from blinking out. Smelt populations won’t rebound during a drought, but if some fish survive, they could struggle back from the brink when precipitation and freshwater flows increase. The same is true for other species affected by environmental changes to the estuary.

Q.  This species was once one of the most abundant fish in the Delta. What happened?

The Delta is an incredibly altered place. The pace of change accelerated after the State Water Project went online in the mid-1960s and Delta exports increased. The resulting changes to the Delta ecosystem created conditions less favorable to native species.


Peter Moyle aboard a UC Davis research vessel in Suisun Marsh, has been studying delta smelt since 1975. Photo by Amy Quinton, Capital Public Radio

Exports continued to increase in the 1980s, even during droughts. Delta smelt populations declined and invasive species increased, reducing the smelt’s food supply and preying on its eggs and larvae. Delta flows dragged smelt through the lethal export pumps. Meanwhile, contaminants draining from farms and cities became more pervasive.

By the late 1990’s much of the Delta had become too warm and uninhabitable for smelt. This largely confined them to an arc of habitat from the North Delta to Suisun Bay in diminishing numbers. Then, in 2012, the current drought kicked in, making habitat conditions even worse for the fish.

Q.  Delta smelt supporters say it’s not about a single species, but rather an ecosystem of several native fish in need a healthy delta with natural freshwater inflows. Yet some farmers almost solely blame the delta smelt for massive reductions in surface water deliveries and suggest that if the species is “functionally extinct,” more water could be released. What is your take?

The Delta ecosystem has indeed changed in major ways that make it less habitable for native fish. The delta smelt is one of six government-protected fish species dependent on the Delta. The others are winter- and spring-run Chinook salmon, green sturgeon, longfin smelt and Central Valley steelhead. Several more are candidates for listing.

Those who blame the delta smelt for our water problems are in denial about the severity and frequency of natural droughts in California. In fact, the “water user” that has suffered most during this drought is the environment. From a fish perspective, California has been in an increasingly severe drought since the 1960s. This is reflected in the decline of delta smelt and other fish.

Photo: UC Davis

An adult delta smelt caught in a survey of fish in the Sacramento-San Joaquin Delta. Photo: U.S. Fish & Wildlife Service

In some years, Delta exports have been reduced by as much as 15 percent to protect delta smelt and winter-run Chinook salmon. But this water has benefited the entire Delta ecosystem, which has steadily been deprived of its freshwater inflows over the years.

Most of the fresh water that “flows to the sea” comes into the Delta during the summer to protect Delta farming. This water also keeps salt water away from the big pumping plants that export drinking water to our cities and irrigation water for farms. In addition, about half the river water is diverted before it even reaches the Delta.

So, while at times “Delta smelt water” could have provided more water for export, those amounts were small and certainly not nearly enough to alleviate drought conditions.

Q.  What is the case for saving a fish that many call unremarkable and lacking any commercial value? Why should taxpayers spend millions to save it?

Caring for delta smelt is caring for the Delta. This fish is a good indicator of the estuary’s health. If delta smelt are alive and well, other fish, birds, mammals and plants also will thrive.

The delta smelt is a part of California’s heritage. It is one of more than 80 fish species found only in California. Most are in decline. Conserving these California-only species means conserving unique aquatic habitats throughout the state. So caring about these native fish is really about caring for what’s unique and special about California’s environment.

The smelt is really a beautiful little fish, very delicate and translucent. Japanese harvest a similar smelt species and value it highly for its delicate flavor. I would like to see the delta smelt become so abundant that we could harvest it for export to Japan, like almonds.

Through enactment of the state and federal endangered species acts, the people of California and the nation have deemed it immoral to allow a species to go extinct, if preventable. The laws tell us we should be taking extraordinary measures to prevent extinction.

I see the plight of delta smelt as a test of our willingness as citizens of California to protect our very special fauna and flora for future generations to enjoy and admire. Nevada fish biologist Jim Deacon was lauded for protecting big places through little animals. Wouldn’t that be a great way for our generation of Californians to be remembered?

Q.  What are they doing at the UC Davis Fish Conservation and Cultural Laboratory to save the delta smelt?

This hatchery program was set up in 2007 as a hedge against the smelt’s extinction in the wild and a source of fish for laboratory studies of the species’ physiology, toxicology and behavior.

Delta Smelt Refuge facility with tanks for genetically diverse smelt populations.

Delta smelt rearing tanks in captive breeding facility run by UC Davis near Stockton. Photo by Dale Kolke/California Department of Water Resources

Thanks to Joan Lindberg and Tien-Chieh Hung, the lab became one of the most sophisticated aquaculture operations in the world. Mating is carefully controlled. A few wild smelt are brought in each year to mate with hatchery smelt to avoid creating fish more adapted to the hatchery than to the wild. About 20,000 artificially propagated, genetically diverse smelt are there at any given time. This is an extraordinary accomplishment given how delicate these fish are.

Q.  What do you see as the policy failures by water agencies, both on water supply and demand?

I am a fish expert, not a water expert, so I will try to answer this from the perspective of fish.

I did my first statewide assessment of California native fishes in 1975 and, as far as I could tell, most were doing okay — including delta smelt. But after that, conditions for native fish quickly deteriorated.

Until the 1980s, water policy largely ignored fish, except salmon. Even then, it was largely thought hatcheries could solve all problems. As water projects developed, the fish clearly needed legal protection. But the needs of fish were largely ignored.

Water management increasingly failed to protect Delta fishes during the 1980s and 90s, resulting in the listing of six species under the federal and state endangered species laws. The listings brought attention to the fish but real action was delayed while studies were being done – studies that never seem to be finished.

Though water in California is over-allocated, the water agencies made optimistic assumptions about water availability for fish and were optimistic about engineering their way out of shortages.

Our understanding of how much precipitation is “normal” for California is based on a short record. Analyses of tree rings and other data suggest extended droughts are common in California and other parts of the West, but our water management seemingly continues to be based on a period when we had a lot of rain and snow and little concern for fish.

The most recent manifestation of this mindset is the “coequal goals” mandate of the state’s Delta Stewardship Council and the Bay Delta Conservation Plan. Under this principle, future provisions of water for environment and for human use would have equal weight.

The problem is that water for the environment — water for fish — is already way under-allocated. Truly balancing human and environmental needs would inherently require allocating more water for the environment.

Fox News anchor Chris Wallace questions correspondent William La Jeunesse on the fight over the delta smelt amid the California drought. The national story aired April 30. Click on image to view story.

Fox News anchor Chris Wallace and correspondent William La Jeunesse report on the fight over the delta smelt amid the California drought. The national story aired April 30. Click on image to view story.

Further reading

Bennett WA. 2005. “Critical assessment of the delta smelt population in the San Francisco Estuary,” San Francisco Estuary & Watershed Science News

Boxall, B. “A small fish caught in a big fuss.” Los Angeles Times. Feb. 2, 2011

Fox News. “Fight over saving endangered fish amid California drought.” April 30, 2015

Moyle, PB. 2015. “Prepare for extinction of delta smelt.” California WaterBlog. March 18, 2015

Quinton, A. 2015. “Endangered delta smelt may be extinct.” Capital Public Radio. March 16, 2015

Ruyak B. 2015. “UC Davis fish biologist: delta smelt ‘functionally extinct’.” Capital Public Radio, Insight with Beth Ruyak. March 18, 2015

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Keeping accounts for groundwater sustainability

Rob Gailey, Graham Fogg, Thomas Harter, Jay Lund, Helen Dahlke, Richard Frank, Tim Ginn, Richard Howitt, Mimi Jenkins, Bonnie Magnuson, Josué Medellín-Azuara, and Samuel Sandoval Solis

The Sustainable Groundwater Management Act of 2014 creates an opportunity to establish standards for the way California accounts for its stores of groundwater, which provide up to 60 percent of the state’s water supply during droughts.

The new law requires regional agencies to prepare Groundwater Sustainability Plans for “high” and “medium” priority groundwater basins, as designated by the California Department of Water Resources [1].

Earlier this year we suggested an outline for developing the plans in an orderly, scientific and transparent fashion. Central to each plan will be a water budget analysis, which catalogs the conceptual framework and available data on the hydrologic function of groundwater basins. The water budget serves as a summary of knowledge on a basin and a potent screening tool to evaluate approaches for sustainable management.

Water budget analyses may include 1) assessment of conditions during previous periods when current sustainability criteria would have been met and 2) consideration of options to adjust future basin inflows and outflows to achieve sustainability.

If time, financial resources and data availability are limited, the water budget analysis may be the only assessment performed for a Groundwater Sustainability Plan. In other cases, the water budget may be the starting point for more detailed modeling, which is often essential for reducing water budget uncertainties and ascertaining effects of various management options.

A water budget compares inflows and outflows to show change in storage:

Inflows – Outflows = Change in Storage

Because the left side of the equation equals the right side, the term “water balance” is also used. The change in storage will average close to zero over long periods of sustainable management.

Each term in the equation can have several components:

  • Inflows: groundwater flow from neighboring groundwater basins; seepage from natural streams, lakes and wetlands; recharge from precipitation, stormwater runoff, and agricultural return flows; and intentional recharge from infiltration ponds or wells
  • Outflows: well pumping; groundwater flowing to neighboring basins; seepage to springs, rivers, wetlands or lakes; uptake by plant roots
  • Change in storage: gains and losses of water within aquifers, ranging from water stored in coarse sands and gravels to finer silts and clays (where losses are the main cause of land subsidence and are not reversible)

Although the groundwater balance concept is simple, estimating components of a water budget can be challenging. Most wells in California are not metered. Water flows are otherwise hard to measure because they generally occur over large areas and long periods of time. Underground flows, of course, cannot be measured directly because they are hidden. Also, the terms of water budget equations vary over time, making results depend on the period analyzed [2].

Here are some approaches for estimating water budget components:


Importantly, many of the water budget component estimates in the table have large uncertainties and are both time dependent and interdependent. In other words, a groundwater budget is transient, and the transient changes are interdependent among the components. Fortunately, construction and calibration of groundwater flow models can reduce uncertainties and represent transients and interdependencies.

Water budget components and approaches for estimating quantities will vary among basins because of differences in hydrogeologic conditions. For example:

  • Types of recharge and their relative importance will vary among basins. In the Tulare Lake hydrologic region, recharge generally occurs 1) on eastside alluvial fans from precipitation and snowmelt, 2) throughout the basin from agricultural return flows and 3) at artificial recharge sites. In contrast, recharge in the North Coast and Central Coast regions generally occurs from localized agricultural return flows and from more broadly distributed precipitation and runoff.
  • Groundwater inflow and outflow at basin boundaries will be easier to estimate for some basins more than others. For coastal basins, water-bearing formations are sometimes located in valleys cut into much less permeable rock. So it may be reasonable to estimate there is no flow across some basin boundaries. The task for some coastal basins will be evaluating flows at the boundary with the ocean. In the Central Valley and in some regions of Southern California, however, boundaries between basins are usually porous, requiring calculations of inter-basin flows.
  • Evaluating changes in storage will depend on basin geology and variations in groundwater levels over time. Analysis would likely include 1) spatial interpolation of water levels in coarse sediments at different times and 2) quantifying contributions of water stored in different sediments [3]. This evaluation may be easier for less complex basins or basins with better characterization and monitoring.

Preparing Groundwater Sustainability Plans will involve uncertainties, as does most decision-making in life. Stakeholders and experts will differ in their opinions on the significance of the uncertainties in water budget analyses and in projections of future climate, land use, surface water deliveries and other conditions. However, concerns over uncertainties need not preclude action. Often there is sufficient information to proceed on some important actions, even as information to support additional actions is being developed.

A constructive approach for moving forward with the plans may be to 1) accept the inevitability of some uncertainty, 2) implement actions based on current information and 3) plan to adjust actions as new information becomes available.

Uncertainty analysis can play an important role in developing and evaluating management approaches. New data can come from additional basin characterization; monitoring groundwater system responses to management actions; refinement of groundwater budgets, models and ancillary calculations; and updated information on management plans and actions. Water budget analysis will prove useful in performing uncertainty analysis and accounting for new information as it becomes available.

The authors, all with UC Davis, have been examining implementation of California’s Sustainable Groundwater Management Act.

[1] Initial Groundwater Basin Prioritization under the Sustainable Groundwater Management Act

[2] Periods of analysis on the order of several years to decades are likely to be the most useful for evaluating issues related to sustainable management.

[3] Releases from storage occur over the full range of sediment textures in aquifer systems. The time scales of the releases can vary and is longer for finer sediments. Specific circumstances will dictate approaches used to estimate volumes of groundwater released from storage. In some cases, modeling may be used to integrate information about a groundwater system and help estimate storage releases.

Further reading

Lund, J, T. Harter, R. Gailey, G. Fogg, R. Frank, H. Dahlke, T. Ginn, S. Sandoval Solis, T. Young, A. Fisher, R. Langridge, J. Viers, T. Harmon, P. Holden, A. Keller, M. Kiparsky, T. Greene, S. Mehl, J. Gurdak, S. Gorelick, and R. Knight. 2015. “Creating effective groundwater sustainability plans.” California WaterBlog. March 4, 2015

Lund, J. 2015. ”When water counts, accounting matters.” Los Angeles Times. April 24, 2015

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Water rationing and California’s drought

Collecting and using household wastewater to water plants. Photo by Florence Low/California Department of Water Resources

Collecting and using household wastewater to water plants. Photo by Florence Low/California Department of Water Resources

By Jay Lund

California cities and water utilities will be stressed to meet the state’s aggressive urban conservation mandates in this fourth year of drought.

Following Gov. Jerry Brown’s executive order, the State Water Resources Control Board developed specific reduction targets for each major urban water supplier, ranging from 8 percent to 36 percent of per-capita water use in 2013. The proposed “emergency” cutbacks would take effect as early as June 1 and last nine months, to Feb. 28.

For most cities, 2015 will be the first year in the four-year drought that deeply affects them; it has been mostly an environmental and agricultural drought until now. Statistically, a fifth dry year seems likely.

If the urban water-use reductions were imposed gradually over a longer period, they could be achieved through changes in plumbing and building codes, landscaping ordinances and water pricing. But for urgent drought conservation this year, such measures are unlikely to yield enough water savings. Well-motivated voluntary conservation efforts will help, but not by much — usually 5 percent to 10 percent reductions use, as seen last year.

For this year, many California cities will look to water rationing, particularly those facing reductions of 15 percent or more. Some common forms of water rationing are outlined in the table below. 

California began serious urban water conservation during the 1976-77 drought and expanded these efforts during and after the 1988-92 drought.  The rapid imposition of  substantial statewide reductions this year will shape urban water conservation for years to come. 

The reductions will make water available for cities in the future, as well as for the environment and agriculture. But they will also pose challenges for wastewater systems designed for higher flows. 

The substantial reductions this year, and likely next year, will have major financial and rate-making implications for local water utilities, which are the financial and innovation backbone (or perhaps exoskeleton) of California’s decentralized water system

Screen Shot 2015-05-02 at 5.55.42 PM.png

Jay Lund is a professor of civil and environmental engineering and director of the Center for Watershed Sciences at UC Davis

Further readings

Lund, J.R. and Reed, R.U. “Drought Water Rationing and Transferable Rations.” Journal of Water Resources Planning and Management, ASCE, Vol. 31, No. 6, pp. 429-437, November 1995

Rogers, P. “San Jose’s new drought rules: How they will affect you.” San Jose Mercury News. April 27, 2015

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Jobs per drop irrigating California crops

Various crops grown in Monterey County. * FOR EDITORIAL USE ONLY *

Farmworkers harvesting cauliflower in Monterey County. Photo by John Chacon/California Department of Water Resources

By Josué Medellín-Azuara, Jay Lund and Richard Howitt

Some of the most popular drought stories lately have been on the amount of what water needed to produce food from California, as a consumer sees it — a single almond, a head of lettuce or a glass of wine. The stories are often illustrated with pictures of common fruits, nuts and vegetables in one column and icons of gallon water jugs representing their water usage in the other.

But there are more than two columns to this story. The amount of water applied to crops also translates into dollars and jobs — the main reasons for agriculture’s existence in California. 

Here are multiple columns of data to better understand California’s crop water use and the revenues and jobs it is intended to produce.

Prepared by Josué Medellín-Azuara, Research Scientist, UC Davis Center for Watershed Sciences. jmedellin@ucdavis.edu

Prepared by Josue Medellin-Azuara with the assistance of Nadya Alexander, UC Davis Center for Watershed Sciences. Contact: jmedellin@ucdavis.edu

The charts below illustrate the data. A principal conclusion is that crops with the highest economic “pop per drop” — revenue per net unit of water — also usually have the highest employment per land area and water use.barchart





Other observations from the data:

  • As a global food basket for fruits, vegetables and nuts, California’s net crop water use in 2010 was about 20 million acre-feet on 9.4 million acres of irrigated land. Gross revenues were about $36.7 billion.
  • The top 5 crop group in revenue per unit of water use are grown on about 25 percent of California’s irrigated cropland and account for 16.4 percent of all the net water use. Those crops are responsible for two-thirds of all crop-related employment.
  • Grains, livestock forage and other field crops rank lower in revenue and jobs per drop because the farming is highly mechanized, requiring relatively little labor. These crop groups nonetheless are critical to the livestock industry. California’s dairy production is the largest in the country.
  • Vegetables, horticulture, fruits and nuts account for more than 90 percent of employment directly related to crop production.
  • Farm contractors, who provide bulk labor for growers, supply about half the labor force for most crop groups.
  • California agriculture accounts for about 400,000 full-time jobs (or their equivalent), including 172,000 in crop production, 29,000 in livestock and dairies and 193,000 in agricultural support services (contract labor). Some studies suggest that many California farm jobs  are part-time, with an average of two jobs for each full-time equivalent job.

California agriculture will use less water this year and in the long run. Several factors will lead to long-term reductions in farm water use in many areas of the state. Those include the state’s new groundwater legislation, ongoing salinization and urbanization of cropland, and increasing environmental water requirements.

The drought has raised understanding of these inevitable reductions. But the growing market value of California’s specialty crops and growing yields per acre and per gallon will keep California agriculture healthy in most cases

Growing scarcity of water for agriculture is probably best managed using water markets and pricing so the industry and the state can make the most of limited supplies. Efforts to impose detailed arbitrary limits on crops and regions are unlikely to serve the economic and environmental interests of California, but rather distract from discussions needed for long-term progress.

Josué Medellín-Azuara, Jay Lund and Richard Howitt are with the UC Davis Center for Watershed Sciences. Medellín-Azuara is a research scientist, Howitt is a professor emeritus of agricultural and resource economics, and Lund is a professor of civil and environmental engineering and director of the center.

Further reading

California Department of Water Resources. 2015. “Irrigated crop acres and water use.” Last visited April 24, 2015

Martin P. and Taylor E. 2013. “Ripe with Change: Evolving Farm Labor Markets int he United States, Mexico and Central America.” Migration Policy Institute, Washington, D.C. Last visited April 24, 2015

Medellin-Azuara J. and Lund J.R. 2015. “Dollars and drops per California crop.” California WaterBlog. April, 14, 2015

Sumner D. 2015. “Food prices and the California drought.” California WaterBlog. April 22, 2015

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Food prices and the California drought

Water, a precious commodity, irrigates a field in southern San Joaquin Valley. wheat. near Bakersfield. Photo nu John R. Chacon/California Department of Water Resources

A wheat field near Bakersfield, Calif., March 2015. Photo by John Chacon/California Department of Water Resources

By Daniel A. Sumner

California’s drought has been tough on farms and especially painful for farm workers in the Central Valley. But consumers of California-produced food have been spared large price increases.

Despite the severity of the drought and California’s dominant market shares in many foods – especially fruits, vegetables and tree nuts – consumers saw only small food price effects last year and are unlikely to notice much price impact in 2015. The reasons derive from California’s geography, irrigation plumbing system, the economics that drive the distribution of irrigation water among crops and the basics of food supply and demand.

The reduction in irrigated crop acreage – about a half million acres last year and likely much more this year – has been and will be mostly field crops such as rice, cotton, hay and corn silage. These crops affect food prices only indirectly and global markets establish prices for most of these crops. California’s output is a small share, and so has little effect on prices.

View of strawberry fields, Elkhorn Sough Reserve and the Monterey Bay.

Strawberry fields on Monterey Bay, Calif., 2013. Photo by John Chacon/California Department of Water Resources

The food crops for which California has a large market share and California production can affect prices – almonds, pistachios, walnuts, fruits, grapes, berries and many vegetables – typically generate high revenue per unit of water. So, where possible, farmers continue to shift scarce and expensive water from field crops to these crops. Farmers have added incentives to shift water to their tree and vine crops to protect their long term investments in these perennial crops.

Additionally, many of the produce crops grown predominantly in California are concentrated in the state’s coastal regions where cuts in surface water deliveries have been smaller and groundwater remains available.

California dairy production will be down this year mostly because of low global dairy product prices, but also because the drought has caused higher California hay and silage prices that boost production costs. But the tendency of drought to slightly raise national prices of cheese, butter and milk powder is swamped by national and global market factors that have lowered dairy product prices.

harvesting swiss chard.

Harvesting swiss chard in coastal California, 2013. Photo by John Chacon/California Department of Water Resources

California ranchers have reduced their cattle herds because of dry pastures, but this has had little effect on beef prices because the state’s share of the North American cattle production is so small.

Even when farm prices rise, retail food prices often show little response. The farm commodity share in what consumers pay tends to small compared with other costs in the chain of marketing, labor, transportation and packaging. That means even a 10 percent higher price of a food commodity at the farm could mean a price hike of only 2 percent or 3 percent for consumers.

The impact of the California drought nationally and internationally may not be noticeable given all the other variables that determine food prices. For example, this year the strong dollar is reducing export demand, especially for dairy products and tree nuts.

The bottom line is farmers are scrambling to efficiently use what water they have –largely stored in underground aquifers – to keep food supplies available, especially for crops where substitutes from elsewhere are not readily available.

What if this drought continues? Clearly, each year of drought will force farmers to idle more cropland, eventually affecting prices for California specialty crops. Beyond that, no one has yet carefully developed a timeline of consequences for water supply, food production and food prices should the drought continue for many more years.

Daniel A. Sumner is director of the UC Agricultural Issues Center and the Frank Buck Professor in the Department of Agricultural and Resource Economics at UC Davis.

Further reading

McClurg, L. 2015. “Drought not likely to cause higher grocery billsCapital Public Radio. April 20, 2015

York T. and Sumner DA. 2015. “Why food prices are drought-resistant.” The Wall Street Journal. April 12, 2015

Upcoming event


Integrated Environmental Modeling
Ocean, estuarine and watershed systems
May 21-22, 2015
UC Davis

Please join us for this international workshop on advancing environmental modeling. 

We are bringing together experts from Europe, Asia and across the U.S. to explore ways to improve the development, application and integration of modeling for multipurpose management of ocean, estuarine and watershed systems.

Community-based modeling, public domain platforms and integrated modeling from various systems will be discussed. A white paper developed from workshop proceedings will be prepared and released to improve modeling integration. 

Admission is free, but please register in advance:  


Further information: integrated modeling.ucdavis.edu

Organizers: Peter Goodwin and Chris Enright, Delta Stewardship Council/Delta Science Program; Josué Medellín-Azuara and Jay Lund, UC Davis Center for Watershed Sciences; Benjamin Bray, California Water and Environmental Modeling Forum

Sponsors: National Science Foundation in partnership with the California Water and Environmental Modeling Forum and the International Association for Hydro-Environment Engineering and Research


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Dollars and drops per California crop

Aerial view of rice fields near Sacramento, California. Photo by Paul Harnes/California Department of Water Resources

Rice fields near Sacramento in 2009. Photo by Paul Harnes/California Department of Water Resources

By Josué Medellín-Azuara and Jay Lund

When it comes to water, California’s irrigated agriculture is always under the public magnifying glass because it is the largest managed water use in the state and the economic base for many rural areas. During a prolonged drought like the current one, however, crop water comes under a microscope.

We have compiled a table to help answer questions on which crops use the most water and which crops provide the most economic “pop per drop.”

The estimates are very broad because California is so diverse in crop varieties, agricultural practices and local water availability. But the numbers are still useful for comparison purposes.

Note that the amount of water applied to a crop – “gross use” – is not the same as its “net use,” as some of that water seeps underground and replenishes aquifers or is reused downstream.


Some observations about the data:

  • The “truck (vegetables) and horticulture (garden plants)” crop group has the highest revenue per net water use, followed by the “fruits and nuts” group. Together, these two large crop categories account for nearly 86 percent of all crop revenue, but occupy only 47 percent of the irrigated cropland and use just 38 percent of the water applied to that land.
  • Fruits and nuts are grown on about one-third of the irrigated cropland and use one-third of the water, but produce nearly 45 percent of the total crop revenue.
  • Alfalfa, corn irrigated pasture and other livestock fodder account for nearly 37 percent of all net water crop use, but produce less than 7 percent of total crop revenue. However, the ranches and dairies that depend on these foodstuffs generate more than 22 percent of California’s agricultural production value, which totaled $45 billion in 2012.
  • Rice fields use a lot of water but also provide important bird habitat.

Josué Medellín-Azuara is a senior researcher and Jay Lund is a professor of civil and environmental engineering with the UC Davis Center for Watershed Sciences.

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Making every drop count in drought – and deluge

A swollen Cosumnes River in wet years and can help recharge local aquifers, providing much needed drinking water and irrigation supplies during droughts. UC Davis

A swollen Cosumnes River earlier this year helped recharge aquifers in the Lodi area, providing much-needed drinking water and irrigation supplies during the drought. Photo: UC Merced

By Joshua Viers and Graham Fogg

A little publicized but highly curious part of the emergency drought legislation signed by Gov. Jerry Brown last month advances hundreds of millions of dollars to shore up and replace aging levees in flood prone areas of the state.

Drought relief through better flood control? Really?

As it turns out, some flood protection projects are important during droughts. Strategically removing sections of old levees or rebuilding them hundreds or thousands of feet from their original riverbank sites can significantly replenish aquifers during wet years, providing badly needed supplies during droughts.

The drought relief package accelerates the appropriation of $660 million from a 2006 flood protection bond act (Proposition 1E) that specifically authorizes construction of such “setback levees” because of the groundwater recharge value and other benefits they provide.

Setback levees are not new. The Dutch have them to improve flood control; allowing floodwaters to spill onto undeveloped or farmed floodplains lowers the flood risk for communities downstream. Their use in California, however, has been much more limited. Local flood control and reclamation districts have focused more on keeping century-old levees intact (Suddeth, 2010).

Some agencies are beginning to rethink this approach as growing numbers of studies point to the multiple economic and environmental benefits of reconnecting rivers with their walled-off floodplains.

It’s easy to forget the Central Valley was once a vast wetland (Whipple et al, 2012). Before we built dams and straightjacketed rivers with levees and riprap, floodwaters would swell onto floodplains (Mount, 1995). The water would percolate into the ground and refill local aquifers. Inundated floodplains also served as nurseries for fish, with abundant insect food and ideal water temperatures for growing bigger and faster – improving their odds of survival in the ocean (Jeffres et al, 2008).

Today, with only 5 percent of the floodplains left undeveloped, California affords few opportunities for floodwaters to restock local aquifers (Hanak et al, 2011). The levees built in the late 1800s and early 1900s to hold back floodwaters from cities and farms now stand as barriers to residents and farmers needing to expand groundwater supplies for drinking water and irrigation.

Three years ago our team of watershed scientists set up an experiment on the Cosumnes River Preserve near Lodi to better understand the relationship of river levees to groundwater recharge. The Nature Conservancy removed about 750 feet of old riverside levee and breached additional levees to increase access of floodwaters onto the floodplain. Scientists monitored the biophysical response.

Researchers found that moving levees on the Cosumnes River can help recharge groundwater. From left, scientists on the project include Drew Nichols from UC Davis, Christina Bradley from UC Merced, Carson Jeffres of UC Davis and Marilyn Fogel of UC Merced.

Researchers found that removing a section of old levees on the Cosumnes River Preserve appreciably restocked local aquifers. From left, scientists on the project include Drew Nichols of UC Davis; Christina Bradley, UC Merced; Carson Jeffres, UC Davis; and Marilyn Fogel, UC Merced. Photo: UC Merced

Preliminary results have been encouraging. Removing the levee on the Nature Conservancy’s 500-acre experimental floodplain appreciably replenished local aquifers and reduced flood risks for area landowners. Just a brief storm in early February added roughly 100 to 300 acre-feet of water to local groundwater stores.

Now that this floodplain will become inundated more frequently, the recharge will continue to grow with each year, possibly resulting in about three times more recharge than would occur from irrigation. The annual amount of net groundwater recharge might amount to 1,000 acre-feet, or more – not bad for such a small area.

Building setback levees is expensive. A 3,400-foot-long structure and associated riparian restoration planned along the lower Feather River in Sutter County is estimated at $20 million. But in reconnecting rivers to their floodplains, these projects can yield the multiple long-term benefits of reduced flood risk, increased groundwater recharge and improved wildlife habitat.

Some communities in the Sacramento-San Joaquin Delta may find this room-for-rivers approach particularly beneficial. It may be more economical to reduce flood risk by expanding floodplains rather than shore up aging levees to meet the new 200-year flood protection requirement. The approach also may be attractive to some communities in the San Joaquin Valley where groundwater overdraft is most pronounced.

The best time to prepare for floods is before they happen. Making every drop count during a deluge can pay dividends when droughts recur and wells start to dry up.

Joshua Viers and Graham Fogg are scientists with the University of California’s Water Security and Sustainability Research Initiative. The groundwater recharge experiment on the Cosumnes River Preserve is conducted in cooperation with the California Department of Fish and Wildlife, Point Blue Conservation Science and the Nature Conservancy.

Further reading

Cosumnes Research Group projects, UC Davis Center for Watershed Sciences

Dutch “Room for the River” program 

Fleckenstein, J., M. Anderson, G. Fogg, and J. Mount. 2004. “Managing surface water-groundwater to restore fall flows in the Cosumnes River.Journal of Water Resources Planning and Management 130, pp. 301-31

Hanak E, Lund J, Dinar A, Gray B, Howitt R, Mount JF, Moyle P, Thompson B. 2011. Managing California’s Water: From Conflict to Reconciliation. Public Policy Institute of California

Jeffres, C., J. Opperman and P. Moyle. 2008. “Ephemeral floodplain habitats provide best growth conditions for juvenile Chinook salmon in a California river.” Environmental Biology of Fishes 83 (4): 449-458

Mount, J. and Twiss, R. 2005. “Subsidence, sea level rise, and seismicity in the Sacramento-San Joaquin DeltaSan Francisco Estuary and Watershed Science, 3(1)

Mount, J. 1995. California Rivers and Streams: The Conflict between Fluvial Process and Land Use. University of California Press. Berkeley, Calif.

Suddeth, R., J. Mount, and J. Lund. 2010. “Levee Decisions and Sustainability for the Sacramento-San Joaquin Delta.” San Francisco Estuary and Watershed Science 8 (1)

Time lapse video of flooding on Cosumnes River, winter 2014-2015, UC Davis Center for Watershed Sciences

University of California Water Security and Sustainability Research Initiative

Whipple AA, Grossinger RM, Rankin D, Stanford B, Askevold RA . 2012. Sacramento-San Joaquin Delta Historical Ecology Investigation: Exploring Pattern and Process. Publication #672, San Francisco Estuary Institute-Aquatic Science Center, Richmond, Calif.


Integrated Environmental Modeling
Ocean, estuarine and watershed systems
May 21-22, 2015
UC Davis

Please join us for this international workshop on advancing environmental modeling. 

We are bringing together experts from Europe, Asia and across the U.S. to explore ways to improve the development, application and integration of modeling for multipurpose management of ocean, estuarine and watershed systems.

Community-based modeling, public domain platforms and integrated modeling from various systems will be discussed. A white paper developed from workshop proceedings will be prepared and released to improve modeling integration. 

Admission is free, but please register in advance:  


Further information: integrated modeling.ucdavis.edu

Organizers: Peter Goodwin and Chris Enright, Delta Stewardship Council/Delta Science Program; Josué Medellín-Azuara and Jay Lund, UC Davis Center for Watershed Sciences; Benjamin Bray, California Water and Environmental Modeling Forum

Sponsors: National Science Foundation in partnership with the California Water and Environmental Modeling Forum and the International Association for Hydro-Environment Engineering and Research


Posted in Uncategorized | 7 Comments

Exotic animals deployed as Delta ‘weed whackers’


Coast guard crews keep close watch on the pod of hippos grazing in and around the weed-infested Stockton Deep Water Ship Channel. Photo courtesy of U.S. Coast Guard

By Nestle J. Frobish

Visitors to the Sacramento-San Joaquin Delta are doing double takes lately as they encounter some newly introduced “biological controls” to keep a fast-spreading waterweed from damaging boat propellers and choking off waterways.

Working with state water officials, UC Davis scientists last month released a herd or “bloat” of hippopotamuses from Botswana to chow down on vast mats of water hyacinth that also threaten to clog the intake to the California Aqueduct near Stockton.


Water hyacinth in Delta. 

Elsewhere in the Delta, the researchers also planted hyacinth-loving manatees imported from Florida and giant guinea pig-like rodents from Brazil called capybaras.

The menagerie of radio-tagged herbivores is part of a yearlong experiment in more natural and, some say, more effective, controls for curbing the menacing growth of non-native aquatic weeds in the Delta.

Source: Wikicommons

A hippopotamus pokes its head out of the hyacinth-covered Clifton Forebay in the Delta. Source

Enlisting hippos in the biowarfare is the brainchild of Robert Broussard, a professor with the UC Davis Center for Watershed Sciences who has long touted biological controls as a cost-effective way to keep the growth of hyacinth in check.

“What better way to fight an alien species than by introducing still more alien species?” Broussard said.

State and local agencies have poured millions of dollars into chemically and mechanically clearing Delta waterways of the hyacinth, a floating ornamental plant, and the submerged Brazilian Waterweed. But this year the combination of severe drought and slower-flowing, nutrient-laden water has created a perfect storm for waterweed growth. There is no known way to eradicate the weeds.

Source: California Department of Water Resources

In 2014, the state treated 2,617 acres of water hyacinth in the Delta with the herbicides glyphosate and 2,4-D. Source: California Department of Water Resources

In some areas the invasive plants have grown so dense that they have threatened not only boat safety and the Delta’s ecological balance but also cargo ship traffic and the state’s water supply.

“Hippos were the furthest things from our minds when we asked UC Davis to find alternative solutions,” said Terry Drinkwater, spokesman for the California Department of Water Resources. “But, I must admit, when it comes to water hyacinth, these river horses are as hungry as, well, horses.”

In their native African habitat, hippos mainly eat aquatic plants, including hyacinth, which they devour at a rate of 200 to 300 pounds a day. The mammal’s affinity for the plant inspired the character “Hyacinth Hippo,” the prima ballerina from the “Dance of the Hours” sequence of Disney’s Fantasia. 


Brazilian waterweed. Photo: California State Parks

“We believe the rate of consumption will be even higher in the Delta with Brazilian waterweed spicing up the mix,” said Broussard, adding that he routinely blends the weed into his own diet of mainly Cajun cuisine.

Officials are taking special measures to keep onlookers at bay because hippos are highly territorial and would likely attack people who encroach on their turf.


Students of UC Davis professor Peter Moyle (background) pose with a manatee last week before releasing the mammal into Delta waters. Photo by Bo Manfree/UC Davis

The Coast Guard has volunteered a crew to shepherd the bloat of hippos currently grazing in the Clifton Court Forebay, a reservoir that serves as the intake for California Aqueduct diversions to Southern California. Working from jet skis, the crew has been herding the hippos between the forebay and the Stockton Deep Water Ship Channel, where boating and shipping has been stymied by floating mats of hyacinth.

Coast Guard Lieutenant Commander Quinton McHale called the effort in the Delta a “war on weed” and said the public safety interest is no different from law enforcement’s effort to combat marijuana growing along California’s north coast.

“You might as well call the Delta the ‘Emerald Triangle,’” McHale said in a recent interview aboard his patrol board, PT-73.

Stockton Mayor Anthony Silva said he plans to promote the hippos as another tourist attraction for the destination city.

UC Davis water science student coax a capybara into the waters at the Delta Yacht Club of the San Joaquin River. The marina is infested with water hyacinth. The rodent is known to devour up to 40 pounds of the invasive weed a day. Photo by Bo Manfree/UC Davis

“I’m just trying to think of everything,” Silva said. “You just know darn well there’s got to be a way we can make money off those big bad boys. Hippos in Stockton is a wacky idea, so we’re calling them ‘Weed Whackers’. Get it?”

Researchers will be comparing the hippos with the more gentle manatees and the web-footed capybaras on feasibility, cost and effectiveness in the waterweed control experiment.

Follow-up work will include a special genetic breeding program to create more voracious aquatic herbivores. “If this doesn’t work, we will be considering barriers in the Delta to limit the spread of waterweeds,” said Cornelius Biemond, deputy director of water supply at the Department of Water Resources.

Jake Lunge, director of the Center for Watershed Sciences, said that adding these “four-legged locusts” to the state’s arsenal of pesticide spraying boats and mechanical waterweed harvesters will likely boost the state’s water supply during this fourth year of severe drought.

“Grazing these vast mats of hyacinth will reduce evapotranspiration and save a lot of water,” said Lunge, a civil professor of ornamental engineering.

“This could help keep California from running out of water by the end of the year.”

Nestle J. Frobish, former chairman of the Worldwide Fair Play for Frogs Committee, is curator of the UC Davis Center for Watershed Sciences.

Further reading

Andersen, T. “Water hyacinth thrives in drought-stricken Delta.” Bay Nature. Dec. 22, 2014

Breitler, A. “Stockton mayor floats an idea: Bring in manatees.” The Record (Stockton). Nov. 8, 2014

Breitler, A. “Port of Stockton: Vessel stopped by tangled mats of hyacinth,” The Record (Stockton)Oct. 28, 2014

Fitzgerald, M. “Hyacinth? Think giant amphibious hamsters.” The Record (Stockton). Nov. 3, 2013

Hippopotamus Stew. Cooks.com

Jackson, W.T. and Paterson, A.M. (1977), “The Sacramento-San Joaquin Delta – The evolution and implementation of water policy – an historical perspective.” Contribution No. 163. California Water Resources Center, UC Davis

Miller, G. “The crazy, ingenious plan to bring hippopotamus ranching to America.” Wired. Dec. 20, 2013

MSNBC picks up California WaterBlog story on Delta hippos

Posted in Uncategorized | 38 Comments

The California Drought of 2015: A preview

Dry fields and bare groves looking west toward the Coast Range, near San Joaquin, Calif. Photo by Gregory Urquiaga/UC Davis, 2014

Dry fields and bare groves looking west toward the Coast Range, near San Joaquin, Calif. Photo by Gregory Urquiaga/UC Davis, 2014

By Jay Lund

This fourth year of drought is severe, but not yet the driest ever. The drought’s impacts are worsened by record heat, which has dried out soils and raised the demands for irrigation, and the historical high levels of California’s population, economy, and agricultural production, and historical low levels of native fish species. There is need for concern, preparation and prudence, but little cause for panic, despite some locally urgent conditions.

How dry?

This year will be about as dry as last year. This is bad, as 2014 was the fourth to eighth driest year in 106 years of recordkeeping, by most reasonable reckonings. This year will be a little different overall, but quite different in some areas, both better – Santa Cruz – and worse – eastern San Joaquin Valley.

Statistically, last year’s drought is about a one in 15-30 year event. With a changing climate and growing water demands, we should prepare for such droughts occurring more than once a generation.

As detailed below, Northern California will be critically dry, having about the same precipitation as 2014 (more in some basins), less snowpack and more storage in some of the largest reservoirs.

The southern Central Valley is as dry or drier than 2014, with abysmal precipitation and snowpack. The western side benefits from having more water stored in San Luis Reservoir than in 2014, but the eastern side has less water remaining in its major reservoirs. Southern California is in similar shape as in 2014 for surface water.  Little time is left in California’s “wet” season, and the forecast for the coming week or so is quite dry. What we see is probably what we’ve got.

Water allocations for the State Water Project are small (20 percent), but better than last year’s 5 percent allocation. Federal Central Valley Project allocations are likely to be 75 percent (and perhaps 100 percent) for higher-priority contractors, 25 percent for cities, and zero for everyone else.

Some locally supplied eastern San Joaquin Valley irrigation districts are delivering no more than 30-35 percent of normal supplies; Merced Irrigation District is delivering no surface water.

Junior water-right diversions in the Central Valley will be curtailed. After reservoir withdrawals last year and little refill this year, eastern San Joaquin Valley will be hit much harder this year. Tulare basin water shortages are about like 2014 or worse, and Sacramento Valley shortages are about the same or a bit less.

Almost the entire state has less groundwater because of three previous years of drawdown. More wells are likely to go dry, particularly for rural households and small water systems, but probably also some irrigation wells.

What will we do?

California will not run out of water this year, or next, if we are careful. We will respond mostly as we did last year, with some modest changes.

In rough order of importance, California will make up most of this year’s water shortage by:

  • Additional groundwater withdrawals of perhaps 5 million or more acre-feet
  • Reductions in urban and environmental water uses and agricultural fallowing — totaling perhaps 4 million acre-feet
  • Shifting perhaps 1 millon acre-feet of water use from lower to higher economic values through water markets
  • Depleting reservoir storage by perhaps 1-2 million acre-feet
  • Increasing wastewater reuse and other conservation efforts

Making rain is not an option.

In many places, groundwater will be less available and farther from the surface than last year, with more dry wells and more expensive pumping. Somewhat more surface water will be available in some places, including the North Coast, Santa Cruz, Sacramento Valley and western San Joaquin Valley. Less will be available for eastern San Joaquin Valley. Further reductions in urban water use are likely for  the Bay Area and Southern California.

Drought impacts on fish and wildlife and hydropower should be similar to those in 2014.

California is not running out of water

Economic and environmental factors will dampen many popularly espoused or feared actions, such as widespread ocean desalination, extensive capturing of stormwater, vast reuse of treated wastewater, eliminating exports of water-intensive foods, abandoning major irrigation districts, fog water collection, iceberg towing and importing water from Canada, the Colombia River, the Great Lakes or anywhere else.

Less extreme water management activities should be adequate, less costly and better environmentally, even for much more extreme droughts than today’s. California is not running out of water.


Droughts bring public and political attention needed to make major changes in water management, such as last year’s historic groundwater legislation. Strategic changes usually require serious long-term problems and thinking, and the urgency of a drought or flood to focus policy discussions.

What changes are likely from this year’s drought? It is hard to know now, but here are some promising candidates:

  • Water measurement and accounting. The 2009 drought brought legislation that began improving basic data on surface water use and groundwater levels. Much more is needed to tighten California’s water accounting closer to that of other western states. Improved water-use data is unlikely to require massive new reporting, but rather improved coordination of existing reporting, some new reporting, and perhaps remote sensing estimates of crop water use (as is done in Idaho). Some additional reporting, such as requiring large water users to “call” their use during drought, would improve use of available water and add reliability to both senior and junior water rights. For better accounting to occur, the state needs a common comprehensive and workable regional water accounting system serving both the State Water Resources Control Board and the Department of Water Resources.
  • Groundwater. A dry 2015 seems only likely to accelerate implementation of local and state groundwater sustainability efforts. Perhaps the best outcome would be legislation to speed groundwater basin adjudications and better empower and guide local groundwater sustainability agencies. Consolidating state groundwater data and analysis now scattered across agencies and programs would be another positive outcome.
  • Water markets. More expeditious and transparent trading of water rights and longer-term water rights contract. From a statewide perspective, the amount of water traded would be small, but the economic and environmental benefits would be great. Water markets are also probably the best means to provide flexibility and incentives needed to improve groundwater recharge, coordinate storage operations, appropriately conserve water, and revitalize environmental water management.
  • Reducing net water use. A primary response to water shortage is to reduce water use in ways that conserve the most water with the least economic and environmental cost. This applies to all water-use sectors during droughts and in the longer term. Improving water rate structures and economic incentives with pricing and markets will be important here, even for some environmental water uses.
  • Sacramento-San Joaquin Delta. Water diversions from the Delta are unfortunately central to California’s water system. They will be less during a drought, but what remains becomes quite valuable. The economic value of the diversions will likely increase with climate change and groundwater sustainability, as local areas seek additional external water supplies. After groundwater, the Delta is probably the state’s most strategic water problem. This year’s drought will provide opportunities and motivations for long-term progress on managing the Delta.

Overall, the drought of 2015 will be a challenge. We can complain and suffer with the usual lament over water waste (by others, of course), or we can make inconvenient and sometimes costly changes for the better.

Jay Lund is a professor of civil and environmental engineering and director of the Center for Watershed Sciences at UC Davis. 

Some arid details at the end of March

Precipitation and snowpack

No “Miracle March” this year.  We had appreciable precipitation only in December and February — one sizable storm each month. The other months were almost entirely dry for most of California.

North Coast streams are in better shape, but the Sacramento Valley is only slightly wetter than in 2014. San Joaquin and Tulare basins are about as dry as this time last year, with dry weather forecast for the short remainder of the “wet” season.  2015 could be the driest year of record for the southern Central Valley.

Snowpack is a little worse than last year, perhaps the driest on record statewide.

As of March 29, the Northern Sierra (Sacramento Valley) Precipitation Index was down to 77 percent of average to date, slightly higher than that for all of 2014. Source: Calif. Data Exchange Center. For updates, click here.

As of March 29, the Northern Sierra (Sacramento Valley) Precipitation Index was down to 76 percent of average to date, slightly higher than that for all of 2014. Source: California Data Exchange Center. For updates, click here.

Precipitation is less than half of average for this time of year in the San Joaquin Valley. Snowpack is a little worse than last year, perhaps the driest on record statewide. Source: California Data Exchange Center. For updates, click here.

Tulare basin has a shorter record though it has the most water use in California. Source: California Data Exchange Center. For updates, click here.

Tulare basin has a shorter record though it has the most water use in California. Source: California Data Exchange Center. For updates, click here.

Snowpack is truly sad, about 6 percent of average for this time of year. Source: California Data Exchange Center. For updates, click here

Snowpack is truly sad, about 6 percent of average for this time of year. Source: California Data Exchange Center. For updates, click here


Reservoir storage is better overall than last year. Still, it’s about 6 million acre-feet below average with no prospect for much refill from snowmelt. The big reservoirs in the Sacramento Valley are 1.3 million acre-feet fuller.

Storage south of the Delta is about the same, though distributed differently. San Luis Reservoir, which serves the state and federal water projects, is about 600,000 acre-feet higher than they were a year ago, but the large reservoirs on the San Joaquin River tributaries are about 600,000 acre-feet lower. Exchequer Reservoir is at 9 percent of capacity.

Source: California Data Exchange Center. For updates, click here

Source: California Data Exchange Center. For updates, click here


Groundwater storage is probably about 6 million acre-feet less than this time last year. Aquifer levels will generally be lower than a year ago in the areas highly dependent on groundwater.

Further Reading

For more data of the status of California’s water supply, explore the Department of Water Resources’ California Data Exchange Center

Fimrite, P. “California drought: Sierra Nevada snowpack hits historic low.” San Francisco Chronicle. March 28, 2015

Kasler, D. “California’s hydro power dries up as drought worsens; utility customers paying more.” The Sacramento Bee. March 27, 2015

Lund, J. “Could California weather a mega-drought?California WaterBlog. June 29, 2014

Lund, J. “The California Drought of 2015: March.” California WaterBlog. March 5, 2015

Lund, J. “The California Drought of 2015: February.” California WaterBlog. Feb. 4, 2015

Lund, J. “The California Drought of 2015: January.” California WaterBlog. Jan. 5, 2015

Lund, J. and J. Mount. “Will California’s drought extend into 2015?California WaterBlog. June 15, 2014

Walton, B. “California drought is not lifting.” Circle of Blue. March 30, 2015

Swain, D. “The Ridiculously Resilient Ridge Returns; Typical winter conditions still nowhere to be found in California.” California Weather Blog. Feb. 16, 2015

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