A salmon success story during the California drought

Salmon spawning in Shasta River. Photo by Carson Jeffres, UC Davis

Salmon spawning in Shasta River. Photo by Carson Jeffres, UC Davis

Looking back on 2014, it’s hard not to feel despair for California salmon.

With drought-stricken rivers running dangerously warm and slow for spring migration, the government was giving millions of young hatchery salmon a lift to the Pacific by truck and barge. Come August, several streams in the Central Valley were drying up. Native fish were absent from many of their summer haunts.

There was, however, a startling exception to the run of bad salmon news.

On the Shasta River, a lifeline for Siskiyou County cattle ranchers, more than 18,000 fall-run Chinook salmon returned from the ocean. That’s more than double the return from the previous fall. More importantly, average returns during the past four years have quadrupled.

No one knows for sure why salmon are surging in the Shasta; many factors affect salmon population dynamics. However, one of those factors — the condition of freshwater habitats — dramatically improved following the exclusion of cattle from a spring-fed tributary, Big Springs Creek.


The 2.2 mile Big Springs Creek (center) is fed from the snow-capped Mount Shasta. The snowmelt runs underground through porous volcanic rock before eventually bubbling up in the creek. The Shasta Basin (outlined) is part of the much larger Klamath Basin (inset). Source: UC Davis Center for Watershed Sciences

Historically, the creek had been a poster child for salmon habitat. Its water originates from springs fed from the snow-capped Mount Shasta, elevation 14,162 feet. As snow melts, it flows underground through porous volcanic rock, rather than running off in streams. Water eventually bubbles up, forming the creek, at about 55 degrees (12 degrees C) — just right for salmon and steelhead trout.

Enriched with nitrogen and phosphorous from volcanic and sedimentary rock, the spring water nourishes an abundance of aquatic plants that teem with insects. The plants provide good cover from fish-eating birds and a respite from high-velocity currents. Fish can eat bugs at their leisure. They grow exceptionally fast and big, increasing their chances of survival when they leave for the ocean and return to the creek to spawn.

All 2.2 miles of Big Springs Creek flows through a cattle ranch that has been operating for more than 100 years. During that time, the luxurious habitat gradually deteriorated. Cows trampled banks and spawning beds and stripped streamside vegetation. They devoured the aquatic plants, making the creek shallower and inhospitably warm in the summer.

The Nature Conservancy had long eyed the Shasta Basin because of its potential to provide high quality habitat for native salmon and steelhead — particularly coho salmon, which are federally designated as “threatened” with extinction. Historically, the 60-mile-long Shasta River was one of the most productive salmon streams in California. As a tributary to the Klamath River, the Shasta contributed only 1 percent of the flow but supported 50 percent of the Chinook salmon (NRCS 2004).

Counts of adult Chinook salmon returning to three tributaries of the Klamath River. Data provided by California Department of Fish and Wildlife

Counts of adult Chinook salmon returning to three tributaries of the Klamath River. Data provided by California Department of Fish and Wildlife

Little was known about the ecology and hydrology of the Shasta River because nearly all of the watershed is privately owned. But a research opportunity arose after the Nature Conservancy bought the 1,700-acre Nelson Ranch, in 2005. The U.S. Bureau of Reclamation, a Klamath Basin dams operator obligated to protect imperiled fish, commissioned the UC Davis Center for Watershed Sciences and Watercourse Engineering Inc. to do a baseline assessment of conditions for salmon and steelhead.

The study confirmed that the river through Nelson Ranch “provides unique and potentially very high quality habitat for rearing juvenile salmonids,” but found the water too warm in the spring and summer for young coho (Jeffres et al. 2007).

Significantly, the 2007 report suggested that temperatures could be improved by repairing Big Spring Creek, just upstream of Nelson Ranch. Researchers found that the creek contributes most of the Shasta’s summertime flow and strongly influences its temperatures for as much as 14 miles downstream (Nichols et al. 2014).

Two years later, in 2009, the Nature Conservancy bought all but 407 acres of the 4,543-acre Shasta Big Springs Ranch along the creek. The organization leased the pastures so ranching could continue, but fenced the entire stream.

Photos by Carson Jeffres, UC Davis

Big Springs Creek in 2008, the year before fencing (left), and six months after cattle exclusion. Photos by Carson Jeffres, UC Davis

Results of the cattle exclusion were dramatic.

In just the first year, the creek transformed from wide, turbid and shallow to cool, clear and deep. Without the constant grazing, the aquatic plants began to grow back, providing shade, protective fish cover and insect habitat. As of last fall, just five years later, annual maximum water temperatures had declined by as much as 7 degrees (4 degrees C) – a substantial and rapid improvement.

Sources: UC Davis Center for Watershed Sciences, Watercourse Engineering Inc.

Annual maximum temperatures at the mouth of  Big Springs Creek. The stream was fenced off to cattle in 2009. Sources: UC Davis Center for Watershed Sciences, Watercourse Engineering Inc.

Likewise, the extent of suitable, connected salmon and steelhead habitat has increased dramatically throughout the creek — and for miles downstream in the Shasta River. Young coho are now seen at several sites in the creek and river, compared with surveys of 2008, when they were observed only in a single pool at the creek’s headwaters.


Video of Chinook salmon in Big Springs Creek by Carson Jeffres, UC Davis, 2012

Time and ongoing research will tell what the recovery of Big Springs Creek means for recovery of Shasta Basin salmon and steelhead. But the huge increase in suitable habitat provides a remarkable benefit for all species that need high quality waters.

The Shasta Basin strategy has useful implications for stream recovery efforts elsewhere. While it’s tempting to focus on the livestock fencing as the solution, three cornerstones laid the foundation for success:

  • An earnest and transparent scientific process to identify ecologically high-value sites and key limiting factors
  • Acceptance of the scientific process, with its uncertain timelines and outcomes, by recovery project funders and interest groups
  • Commitment to implement a solution that maintains the economic well-being of riverside landowners – in this case, cattle ranchers.

Together, these elements paved the way for scientific discovery, both in identifying the major ecological impairments and determining how to address them.

Source: UC Davis Center for Watershed Sciences

Government agencies and nonprofit groups whose management affects salmon and steelhead in the Shasta Basin. Source: UC Davis Center for Watershed Sciences

With habitat recovery in Shasta Basin now underway, other basin landowners can help sustain it. Salmon restoration efforts in the region already enjoy broad support and collaboration among public, private and non-profit entities. Several measures are already established, including controls on irrigation runoff, removal of barriers to fish passage and water transactions that increase streamflows for fish at biologically important times.

Conservation activities at the basin scale are necessary to develop and maintain salmon and steelhead habitat. However, certain ecologically important river reaches are paramount to successful recovery. Good stewardship of these critical reaches leverages the value of all conservation efforts in the basin.

Ann Willis, an engineer and research coordinator with the UC Davis Center for Watershed Sciences, wrote this article with contributions from the center’s Peter Moyle, professor of fish biology, and Michael Deas, president of Watercourse Engineering Inc. of Davis. Center researchers Robert Lusardi, Carson Jeffres and Andrew Nichols also contributed. 

Further reading

Jeffres CA, Dahlgren RA, Kiernan JD, King AM, Lusardi RA, Nichols AL, Null SE, Tanaka SK, Willis AD, Mount JD, Moyle PB, Deas ML. 2009. Baseline Assessment of Physical and Biological Conditions Within Waterways on Big Springs Ranch, Siskiyou County, California. Center for Watershed Sciences, UC Davis

Jeffres CA, Mount JF, Moyle PB, Deas ML, Buckland E, Hammock B, Kiernan JD, King AM, Krigbaum N, Nichols AL, Null SE. 2007. Baseline Assessment of Salmonid Habitat and Aquatic Ecology of the Nelson Ranch, Shasta River, California Water Year 2007. Center for Watershed Sciences, UC Davis

Lusardi RA and Willis AD. 2014. Aquatic plants: unsung but prime salmon habitat. California WaterBlog

Lusardi RA. 2013. How to save salmon: Location, location, location. California WaterBlog

National Research Council (NRC). 2004. Endangered and Threatened Fishes in the Klamath River Basin: Causes of Decline and Strategies for Recovery

Nichols AL, Willis AD, Jeffres CA, Deas ML. 2014. Water Temperature Patterns Below Large Groundwater Springs: Management Implications for Coho Salmon in the Shasta River, California. River Research and Applications, vol. 30 (4)

Willis AD, Nichols AL, Jeffres CA, Deas ML. 2013. Water Resources Management Planning: Conceptual Framework and Case Study of the Shasta Basin. Center for Watershed Sciences, UC Davis

Willis AD, Deas ML, Jeffres CA, Mount JF, Moyle PB, Nichols AL. 2011. Executive Analysis of Restoration Actions in Big Springs Creek March 2008-September 2011. Center for Watershed Sciences, UC Davis

U.S. Environmental Protection Agency. 2003. EPA Region 10 Guidance for Pacific Northwest State and Tribal Temperature Water Quality Standards


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The 2015 drought – so far

Source: Wikimedia Commons

Rain gauge. Source: Wikimedia Commons

By Jay Lund

The California Department of Water Resources does a great job assembling data that can give insights on water conditions during the ongoing drought. They update the information daily (which can be addictive for some of us) on the California Data Exchange Center website.

Here are highlights of water conditions as of January 4:


A drought as bad as last year seems unlikely, but remains a possibility, especially for the Tulare Basin in the southern Central Valley. Rain has arrived, but the drought has not yet left. Fortunately, we have three months left in the wet season. We won’t know much for sure about the 2015 water outlook until March, no matter how eager we want to know. For the Sacramento and San Joaquin valleys, El Nino — the periodic shift of warm water from the Western to the Eastern Pacific — is a poor predictor of runoff in northern and central California.


The December storms helped, but surface water storage remains about 5 million acre feet below average for this time of year. The Sacramento area is in much better shape, but most other areas are worse off or about the same in terms of storage than a year ago.

Source: California Department of Water Resources

Source: California Department of Water Resources

Further information:
– http://cdec.water.ca.gov/cgi-progs/products/rescond.pdf
– http://cdec.water.ca.gov/cgi-progs/reservoirs/RES


The snowpack overall remains about 50 percent of average for early January. Hopefully we will have a decent skiing season.

Source: California Department of Water Resources

Source: California Department of Water Resources

Further information:


Among the most useful DWR data are the daily precipitation indices for the Sacramento Valley, San Joaquin Valley and Tulare Basin.

The Sacramento Valley is at 121 percent of average for early January (its meager snowpack notwithstanding), so it would be extraordinary for the region to end up drier this year than in 2014.

The San Joaquin Valley and Tulare Basin are not accumulating precipitation as fast, with 65 percent and 67 percent of average precipitation respectively for this time of year. At this point, part way through the wet season, it seems plausible — though unlikely — that this year will be as dry as the last in these areas.


Source: Tulare Basin Precipitation Index, DWR. The record on the Tulare Basin appears to be shorter, though this region uses more water than any other part of California.

I hope DWR eventually will add a precipitation index for southern coastal California (south of the Tehachapis) and some indices of water storage in major groundwater basins, where most of California’s water storage resides.

These precipitation indices are telling, particularly the more recent yearly plot lines. Those have daily data so you to see how much each storm contributed to the annual water supply. Such close tracking shows that the difference between a drought and a wet year in California can be due to 3-5 storms, the size of these individual storms, and where these storms hit.

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

Further Reading

Schonher, T. and S. E. Nicholson (1989), “The Relationship between California Rainfall and ENSO Events,” Journal of Climate, Vol. 2, Nov. pp. 1258-1269.

Lund, J. and J. Mount (2014), Will California’s drought extend into 2015?, CaliforniaWaterBlog.com, June 15, 2014

California Weather Blog, http://www.weatherwest.com/

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Drought a ghost of Christmas past — and present

Alan Marciochi

A California Christmas greeting card from 1977, a year of severe drought. Drawing by Alan Marciochi, courtesy of Peter Moyle

By Peter Moyle

I love this cartoon because it says so much about water and droughts in California. Alan Marciochi drew this during the 1976-77 drought. He knew what he was drawing.

A farm boy from Los Banos with a degree in biology, Alan worked for me studying endangered Modoc suckers in remote northeastern corner of California. His main stipulation in working for me was that he had to have the melon harvest season free. He could make more money packing melons in a month or two than he could make working for me in a year. I could not give Christmas bonuses.

Photo: U.S. Fish & Wildlife Service

Modoc suckers dwell in pools of headwater streams flowing through meadows and dry forests, primarily in Modoc County. Photo: U.S. Fish & Wildlife Service

For his field job with me, Alan moved to Modoc County where he soon joined a local band as a banjo player. He gained enough local trust that ranchers allowed us on their land to look for an endangered species, the Modoc sucker. I am happy to report that, partly as a result of that early work, the species has become much more abundant and there are proposals to remove it from its fully protected status.

Drought was just one of many threats to the Modoc sucker at the time. Cattle trampled its habitat during low-flow periods. Irrigators channelized and diverted key streams. Alien brown trout and green sunfish devoured the suckers, especially when they were concentrated in a few pools. Restoration projects have greatly improved conditions for the sucker, but it remains vulnerable to severe drought.

In Alan’s cartoon, the line queuing up to the weary Santa could easily be made up of 120 species of California native fishes, each asking for more water. In this unexpectedly wet holiday season, Santa may be able to appear less weary, but there is still not enough water to go around for all fish and human uses — even in wet years.

The Modoc sucker story suggests we can work things out in ways to sustain our native fishes in a human-dominated landscape, such as on ranches. I like to keep this message of reconciliation in mind, especially during the holiday season. A few large gifts of water to the fish would be nice, however.

Peter Moyle is a distinguished professor of fish biology and associate director of the Center for Watershed Sciences at UC Davis.

Further reading

Moyle, P. B. and A. Marciochi. 1975. Biology of the Modoc sucker, Catostomus microps, in northeastern California. Copeia 1975:556-560

Moyle, P. B. 2002. Inland Fishes of California. Revised and expanded. Berkeley: University of California Press. 502 pp



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New environmentalism needed for California water

The city of Los Angeles’ revitalization of the Los Angeles River exemplifies “new environmentalism, which reconciles human activities to better support and expand habitat for native species. Images show the river today (left), looking north above 1st Street downtown, and an illustration of the same view with public access and habitat for fish and wildlife. Source: Los Angeles River Revitalization Master Plan

By Jay Lund

California needs a new environmentalism to set a more effective and sustainable green bar for the nation and even the world.

For decades, we have taken a “just say no” approach to stop, prevent or blunt human encroachments onto the natural world – often rightly so. Early environmentalism needed lines in the sand against rampant development and reckless industrialization and achieved widespread success. Our air and water is now cleaner even with population and economic growth. Industry, for the most part, is now accountable for its wastes.

Yet, despite these important gains, the classical environmentalism of “no” will ultimately fail. We must shift to “how better?”

Despite decades of earnest efforts and expenditures, human influence on the natural environment continues to grow, albeit at a slower rate. Native species continue to become endangered. Tens of thousands of inadequately tested chemicals still remain in use. Carbon exhausts keep accumulating and warming the planet. Our imprint on nature is subtler but more pervasive and difficult to stymie than we had ever imagined.

In the Sacramento-San Joaquin Delta, more than 90 percent of plants and animals don’t belong there naturally. They have profoundly changed food webs and habitats, mostly to the detriment of native species. Invasive non-native species have been introduced for fishing or escaped from ship ballast water, anglers’ bait buckets or home aquariums. Such environmental changes are not subject to review, and answer to no court.

Classical environmentalism is mostly about stopping new harmful human influences, not reversing the harmful effects of past changes or shaping a more environmentally friendly future. Environmentalism has not substantially reversed the widespread urban and agricultural destruction of wetlands or freed rivers from the concrete and rock that straightened their course.

A new environmentalism is needed that can redirect and reconcile human activities to better support and even expand habitat for native species. Rather than insist on blocking human use to protect nature – a largely quixotic quest now – environmental reconciliation works in and with unavoidably human habitats.

A vivid example of this integration is the planned rejuvenation of the Los Angeles River. Deadly floods in the 1930s led the U.S. Army Corps of Engineers to straighten and pave nearly all 52 miles of the river channel in concrete. In recent years, however, a grassroots campaign to transform the giant, trash-strewn storm drain into something resembling a river has gained political traction. Illustrations in the city’s river revitalization plan show a natural and human-made hybrid. Flood protection would be maintained, but tons of concrete would be replaced with terraced tree-lined banks and wetlands that link bikeways, parks and neighborhoods. The goal is not so much to restore the river but to reintroduce nature to residents of a harshly unnatural environment.

More recently, in the Sacramento Valley, a consortium of private landowners, conservation groups, government agencies and researchers with the UC Davis Center for Watershed Sciences is working to help struggling salmon populations in mutually beneficial ways. The group is investigating how the Yolo Bypass, long used for flood control and farming, could also be managed as a seasonal wetland for fish and water birds. Recent studies indicate the floodway would make a productive salmon nursery at relatively little cost to farmers. Test fish planted on inundated rice fields grew phenomenally faster and fatter than those left to mature in the Sacramento River, earning them the name “floodplain fatties.”


Scientists flooded and stocked thousands of baby salmon on a rice field in the Yolo Bypass in February 2013. Historically, river flooding gave salmon access to much of the Sacramento Valley. Photo by Carson Jeffres

Environmentalism with the more positive and proactive direction of reconciliation has potential to create new habitat for native species, rather than maintaining unsustainable remnants on hospice at great expense.

New environmentalism is about diverse interests working together to create more promising environmental solutions. In contrast, the politics and finance of classical environmentalism often require casting others as villains. Some environmental assaults demand a call to arms. But the public has grown weary of confrontation and standoff, such as the decades of stalemate over the Delta. The resulting inaction has cost both the environment and the economy. Earthquakes, floods, and sea level rise will act to transform parts of the Delta into open water – risking water supplies for millions of acres of farmland and millions of Southern Californians. So far, governing institutions have been unable to lead in responding to inevitable environmental change.

Classical environmental thinking pervades environmental regulation often to the point of impeding environmental progress. Regulatory agencies cannot agree on environmentally beneficial changes unless proposals are almost entirely without negative environmental impacts, often perpetuating an environmentally inferior status quo.

As most ecologists and even politicians now recognize, nature and human activities cannot be kept strictly apart. They must largely be reconciled and even integrated. To be sure, some habitat should remain off-limits. But classical environmentalism alone can only lead to increasingly expensive environmental decline and public derision.

To succeed, environmentalism must move from the era of “no” to an era of “how better.”

Jay R. Lund is director of  the UC Davis Center for Watershed Sciences. This commentary originally appeared in The Sacramento Bee on June 30, 2013.

Further reading

Boxall, B. Oct. 25, 2013. “Can the Yolo Bypass floodplain be managed to nurture salmon?” Los Angeles Times

Leslie, J. Dec. 6, 2014. “Los Angeles, City of Water“. The New York Times

Marris, E. 2011. Rambunctious Garden: Saving Nature in a Post-Wild World. Bloomsbury, New York

Marris, E. and Aplet, G. Oct. 31, 2014. “How to mend the conservation divide.” The New York Times 

Moyle, P. and W. A. Bennett. 2008. “The future of the Delta ecosystem and its fish.” Technical Appendix D, Comparing Futures for the SacramentoSan Joaquin Delta. San Francisco: Public Policy Institute of California

Suddeth, R. Dec. 2, 2014. “Reconciling fish and fowl with floods and farming“. California WaterBlog

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Reconciling fish and fowl with floods and farming

Rice fields on the Yolo Bypass. Photo by Carson Jeffres, UC Davis

Rice fields on the Yolo Bypass, an engineered floodplain of the lower Sacramento River. Photo by Carson Jeffres, UC Davis

By Robyn Suddeth

Floodplains are extremely productive habitats for native fish and birds, yet floodplains in California are cut off from rivers by levees and development. The loss of this severed habitat threatens many native species that evolved to take advantage of seasonal flooding.

Ecologists’ traditional approach to this problem would be to recreate some of the historical floodplain by restoring natural flows and vegetation. In much of California, however, levees, dams and riverside development make restoration impractical.

Recognizing these constraints, reconciliation ecology encourages land and water managers to re-engineer human-dominated landscapes to be more hospitable for native species without significantly diminishing human uses.

California’s Yolo Bypass, an engineered floodplain on the Sacramento River, is an excellent case study of this new approach to native species conservation.

As a doctoral student with the UC Davis Center for Watershed Sciences I recently developed a computer model to balance economic and ecological goals in the bypass under a range of habitat quality assumptions.


The Yolo Bypass conveys floodwaters from the Sacramento, American and Feather river systems. Blue circles mark the western tributaries. Green arrows shows inflows from the Sacramento River. Source: Suddeth, R., 2014. p. 92

Results from this Yolo Bypass Multi-Objective Optimization Model suggest that significant habitat improvement is possible for several fish and bird species at little or no cost to farmers. Further, farming can actually create and in some cases even enhance habitat for fish and birds.

The U.S. Army Corps of Engineers built the bypass more than 80 years ago to protect Sacramento and the southern Sacramento Valley from floods. It lies within the Sacramento River’s historical floodplain and is connected to the river by several weirs. Three miles wide and 40 miles long, the 59,000-acre floodway can carry up to four times the flow of the river’s main channel during large floods.

But the bypass serves several additional economic and ecological purposes: farming, duck hunting, wetland for water birds and shorebirds, and spawning and rearing grounds for several fishes — including endangered spring- and winter-run Chinook salmon.

In the past decade, resource managers and scientists have shown increasing interest in the bypass’ functionality as fish habitat during floods. Studies have shown that young Chinook salmon grow much faster in flooded rice fields on the bypass than they do in the main river channel. The bypass has been widely hailed as the most promising site in the Central Valley for restoring floodplain habitat for fish. The Bay Delta Conservation Plan proposes a notch in the upstream Fremont Weir to increase the frequency and duration of inundation at key times for salmon and Sacramento splittail.

 by Carson Jeffres

In an ongoing salmon-rearing experiment, researchers have found juvenile Chinook planted in flooded rice fields after harvest grow phenomenally faster and fatter than those left to mature in the Sacramento River  — bolstering the hypothesis that access to a floodplain is important to sustaining salmon populations.  Photo by Carson Jeffres

These increased flows are not without controversy. While farming and wetland management on the bypass is adapted to occasional winter flooding, water that stays on fields too long into the spring can delay drawdown for wetland plants that birds feed on, or delay planting of crops. Either way, the growing season is shortened and crop yields reduced, cutting into waterfowl food and farm income.

Flooding the bypass for the benefit of farms, fowl and fish will require a carefully scheduled and controlled low-flow inundation of fields and some landscape re-engineering. Many decisions would need to be made at varying times and places, all with different consequences for each management objective.

Multi-objective optimization models like the one developed for this study can integrate large amounts of data and knowledge and account for the relationships and tradeoffs among different objectives. This is especially useful in reconciliation planning where many uses and variables interact on a landscape and for re-engineering, where many decisions must be considered simultaneously.  

The study used the Yolo Bypass Multi-Objective Optimization Model to test land and water management decisions and maximize net revenues for varying levels of fish and bird habitat quality.


Results of a computer optimization model analysis show that fish and bird habitat on the Yolo Bypass can be improved with little annual costs for farmers. The graph plots habitat quality tradeoffs for fixed annual economic losses, with a Feb. 7 start for flooding and varied habitat assumptions and priorities (salmon and dabbling ducks prioritized on left and all land uses weighted equally for fish on right). Blue area shows where tradeoffs among fish, birds and annual revenues are low for significant gains in habitat quality. Source: Suddeth, R., 2014, p. 111

As for land use, model results suggest that habitat quality could be improved most efficiently by shifting from pasture to seasonal wetland, mostly in the southern bypass. This result persisted under a broad set of runs with varying habitat quality assumptions. Results also often indicated that small additions in rice acreage could improve fish and bird habitat.

Habitat quality and economic performance on the bypass are not solely functions of land use ; they also depend on the extent, timing, duration and depth of flooding. Gates, inflatable dams and other flow-directing structures can manipulate these variables to maximize habitat quality at least cost to farmers.

Following the guidelines listed below, increased flows from a notched weir could create fish habitat and improve bird habitat quality relative to current dry years with no annual revenue losses for farmers or duck club owners. Significant improvements in habitat quality are achievable with additional land-use changes and $100,000 – $200,000 in annual net revenue losses. These losses amount to less than 1 percent of total annual crop revenues on an economically optimized (modeled) bypass, and a loss of 1 – 5 percent of the actual annual farm revenues in 2005 – 2009.

Trading pasture for wetlands or adding acres of rice will have tax implications for Yolo County and financial implications for local farmers and landowners. None of these management changes can occur without first designating who pays for these environmental benefits. The optimization model can help provide detailed and zone-specific information about the economic implications of management decisions and a rough estimate of ecological gains or losses from any changes.

Another potentially required land-use change would be the creation of new wetlands and fields devoted to habitat-friendly crops. Locating these lands close together and near the water source will allow applied water to be more easily managed for depth and duration.

There is much promise for a reconciliation approach to management of the Yolo Bypass that is not costly to farmers and landowners. Crops are a vital component of the overall habitat mosaic – a sign that even heavily modified floodplains like the bypass can be improved for native species without substantially diminishing human use.

Robyn Suddeth currently works as a water policy analyst at CH2M Hill. She can be reached at robyn.suddeth@ch2m.com


Guidelines for managing flood flows for six to eight weeks on Yolo Bypass  

  • Timing.  Under almost all habitat quality assumptions, the best start date for a six- to eight-week inundation lies somewhere in the last week of January or the first few weeks of February. This timing gives farmers a long growing season and best balances the needs of all four species groups. The best start date also depends on duration of flooding. For example, flooding in early February would not significantly benefit shorebirds unless it lasts at least six weeks. The shorter the duration, the more important timing becomes for each species and the harder it is to strike a balance with just one flood event.

  • Depth.  Inundation depth, which varies in space and time during the flood, is the one management decision for which general conclusions are difficult. Depth controls exactly when and where a particular species will have viable habitat within the larger flood mosaic, so small changes in preferences can make a large difference in the optimal pattern. In general, a bypass balanced for fish and birds will benefit most from an inundation that starts sometime in late January or early February with (1) shallow flooding during the first few weeks, usually less than 8 inches for birds; then (2) deeper flooding for the next few weeks (13 – 18 inches) to provide better fish habitat; followed by (3) a mixture of mudflat to moderately deep habitats as waters recede and shorebirds begin to share the system with fish and dabbling ducks. This is the case even for February flooding that spans only six weeks.

  • Duration.  If flooding begins before the last week of February, then it is always valuable – and not necessarily costly – to keep at least some water on wetlands and other lower-value land uses for a full eight weeks if possible. When the computer-simulated flooding was shortened by two weeks, attainable habitat quality decreased by about 25 percent. Long floods increase the availability of flooded habitat to satisfy a wider variety of species preferences.
  • Hydraulic management.  The ability to control the flood footprint throughout the inundation event can significantly increase the cost-effectiveness of flooded habitat quality improvements. Hydraulic management could direct most flooding to the southern bypass where agricultural losses are less. Rice and safflower fields should be drained by mid-March for planting. Flooded rice fields are especially good at producing invertebrates, a staple for fish and birds. Most of the production occurs early during inundation and is fairly self-sustaining. Drainage from these fields could be directed to wetlands and pasture so fish and birds can continue to feast on the bounty.

    Delaying crop planting beyond mid-March could significantly reduce crop yields and revenues in the Yolo Bypass. Source: Suddeth, 2014, Executive Summary

    Delaying crop planting beyond mid-March could significantly reduce crop yields and revenues in the Yolo Bypass. Source: Suddeth, 2014, Executive Summary


Further reading

Fleenor, W. Suddeth, R. Oct. 18, 2013. Innovations in floodplain modeling: A test drive on the Yolo Bypass. California WaterBlog

Howitt, R., MacEwan, D., Garnache, C., Medellin-Azuara, J., Marchand, P., Brown, D., Six, J., Lee, J. 2013. Agricultural and Economic Impacts of Yolo Bypass Fish Habitat Proposals. Prepared for Yolo County. 58p

Howitt, R., J. Medellin Azuara. May 19, 2013. A sweet spot for farms and fish on a floodplain, The Davis Enterprise

Jeffres, C. June 2, 2011. Frolicking fat floodplain fish feeding furiously. California WaterBlog

Mount, J. Aug. 11, 2011. The Benefits of Floodplain Reconnection. California WaterBlog

Sommer, T., B. Harrell, M. Nobriga, R. Brown, P. Moyle, W. Kimmerer and L. Schemel. 2001. “California’s Yolo Bypass: Evidence that flood control can be compatible with fisheries, wetlands, wildlife and agriculture,” Fisheries 26 (8)

Suddeth, R. 2014. Multi-Objective Analysis for Ecosystem Reconciliation on an Engineered Floodplain: The Yoloi Bypass in California’s Central Valley. PhD dissertation. UC Davis

Suddeth, R. 2014. Reconciling fish, birds and farming on California’s Yolo Bypass. Executive summary prepared for the Delta Stewardship Council.

U.S. Department of Interior, et al. 2013. Bay Delta Conservation Plan, Draft EIR/EIS. Chapter 3, Part 1: Conservation Strategy

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How engineers see the water glass in California

Engineering a water glass at 50 percent. Source: xkcd.com

Engineering a water glass at 50 percent. Source: xkcd.com

How do engineers see the water glass in California? The same as they did two years ago when this blog was first posted, though with today’s drought the glass is perhaps down to a quarter full — or three-quarters empty. 

By Jay R. Lund

Depending on your outlook, the proverbial glass of water is either half full or half empty. Not so for engineers in California.

Civil engineer: The glass is too big.

Flood control engineer: The glass should be 50 percent bigger.

Army Corps levee engineer: The glass should be 50 percent thicker.

Mexicali Valley water engineer: If your glass leaks, don’t fix it.

Delta levee engineer: Why is water rising on the outside of my glass?

Dutch levee engineer: The water should be kept in a pitcher.

Southern California water engineer: Can we get another pitcher?

Northern California water engineer: Who took half my water?

Consulting engineer: How much water would you like?

Delta environmental engineer: Don’t drink the water.

Water reuse engineer: Someone else drank from this glass.

Academic engineer: I don’t have a glass or any water, but I’ll tell you what to do with yours.

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

Further reading

Munroe, Randall. Glass Half Empty. xkcd.com

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Shaping water storage in California

By Jay Lund, Maurice Hall and Anthony Saracino

With the continuation of California’s historic drought and the recent passage of Proposition 1, the potential value of additional water storage in the state is an area of vigorous discussion.

In a new study released today, we look at the different roles of storage in California’s integrated water system and evaluate storage capacity expansion from what we call a “system analysis approach.” This approach emphasizes how new storage projects, both above and below ground, can work in combination with one another and in concert with the broader water management system.

Surface water reservoirs provide benefits by capturing water when it is more abundant and storing it for times of greater water scarcity (most commonly storing water from California’s wet winter for its dry spring and summer, but also providing some ability to save water for short droughts). Groundwater in California provides larger capacity storage for the longer term, such as for multi-year droughts, and is a substantial source of water and seasonal storage in places where surface water is limited.

In California’s vast and interconnected water system, storage projects should not be evaluated in isolation. Instead, storage should be considered and analyzed as part of larger portfolios of infrastructure and management actions, including: various water sources; various types and locations of surface and groundwater storage; various conveyance alternatives; and managing all forms of water demands. Such an integrated, multi-benefit perspective and analysis would be more valuable and would be a fundamental departure from most ongoing policy discussions and recent storage project analyses.

Our study and earlier work shows that the ability to utilize additional water storage in California is finite and varies greatly with its location, the availability of water conveyance capacity, and how the system is operated to integrate surface and groundwater storage, conveyance and water demands.

At most, California’s large-scale water system could potentially utilize between 5 and 6 million acre-feet of additional surface and groundwater storage capacity, and probably no more. The limitation stems primarily from a lack of streamflow to reliably fill larger amounts of storage space.

Major water storage expansion proposals

In the long term, this limitation is likely to tighten with a drier climate, though it can loosen somewhat with wetter and more variable streamflows.

The most promising new storage projects would provide annual water deliveries of 5-15 percent of the new storage capacity. Said another way, a storage project with 1 million acre-feet of storage capacity would likely provide an average of only 50,000 to 150,000 acre-feet of new supply a year.

Our study also demonstrates that the water supply and environmental performance of additional storage capacity are greatest when surface and groundwater storage operations are integrated and coordinated. The benefits and likely cost-effectiveness of coordinating surface and groundwater storage and conveyance operations greatly surpass the benefits of expanding storage capacity alone. Integrated operation can expand annual water delivery to as much as 20 percent of the increase in storage capacity.

This does not necessarily mean that the benefits of expanding surface or groundwater storage capacity exceed their substantial costs; we did not delve into benefit and cost calculations. But there is enough water and water demand to take advantage of up to about 5 or 6 million acre-feet of additional surface and groundwater storage within the Central Valley, were this capacity available and in the right places.

This new storage volume would increase California’s total water supply by at most 5 percent and, if targeted appropriately, could provide more reliable supplies for farms and cities as well as more flows at the right time and place for fish and wildlife.

However, expanding water storage is no panacea by itself; it must be combined with other system improvements and actions in an integrated portfolio approach to California’s water system.

Integrated water management and Delta water deliveries


More integrated water management greatly increases water deliveries. This graph shows average delivery increases for various Delta conveyance assumptions and combinations of four surface and groundwater storage expansions in the Sacramento and San Joaquin valleys. Sources: Historical climate data, CalLite water model (described in appendix of storage study)

More integrated water management greatly increases Delta water deliveries. This graph shows average water delivery increases for various Delta conveyance assumptions and combinations of four surface and groundwater storage capacity expansions in the Sacramento and San Joaquin valleys. Sources: Historical climate data and the CalLite water model described in appendix of storage study

Water infrastructure programs purposely designed and implemented to work with other parts of the water system and other water management actions can significantly outperform individual projects in achieving objectives for water supply, healthy ecosystems and flood protection — under a variety of climate conditions (Harou et al. 2010; Connell-Buck et al. 2011; Ragatz 2013).

Studies examining water storage and water management generally should explicitly consider the potential for integrating surface and groundwater storage, as well as conveyance and water demand management for water supply, ecosystems and flood protection. Recent state groundwater legislation could be instrumental in supporting such coordination regionally and locally.

The benefits of integrated management are clear. A transformation is needed in how agencies and stakeholders think about conducting water infrastructure studies if California is going to squeeze the most benefit from our water infrastructure investments, including the Prop. 1 funds.

Jay Lund is director of the UC Davis Center for Watershed Sciences. Maurice Hall is California water science and engineering lead for The Nature Conservancy and Anthony Saracino is a water resources consultant in Sacramento.

Jay Lund talks about water storage study

Further reading

Connell-Buck, C.R., J. Medellín-Azuara, J.R. Lund, and K. Madani, “Adapting California’s water system to warm vs. warm-dry climates,” Climatic Change, Vol. 109 (Suppl 1), pp. S133–S149, 2011

Hanak, E., J. Lund, A. Dinar, B. Gray, R. Howitt, J. Mount, P. Moyle and B. Thompson, Managing California’s Water:  From Conflict to Reconciliation, Public Policy Institute of California, San Francisco, CA, 500 pp., February 2011

Harou, J.J., J. Medellin-Azuara, T. Zhu, S.K. Tanaka, J.R. Lund, S. Stine, M.A. Olivares and M.W. Jenkins, “Economic consequences of optimized water management for a prolonged, severe drought in California,” Water Resources Research, doi:10.1029/2008WR007681, Vol. 46, 2010

Krieger, J.H. and H.O. Banks (1962), “Ground water basin management,” Cal. Law Review. V. 50:56

Lund, J., A. Munévar, A. Taghavi, M. Hall and A. Saracino, “Integrating storage in California’s changing water system,” Center for Watershed Sciences, UC Davis, November 2014

Lund, J.R. and T. Harter (2013), “California’s groundwater problems and prospects”, CaliforniaWaterBlog, Jan. 30, 2013

Lund, J.R. (2012), “Expanding Water Storage Capacity in California,” CaliforniaWaterBlog, Feb. 22, 2012

Lund, J.R. (2011), “Water Storage in California,” CaliforniaWaterBlog, Sept. 13, 2011

Ragatz, R.E. (2013), “California’s water futures: How water conservation and varying Delta exports affect water supply in the face of climate change,” Master’s thesis, Department of Civil and Environmental Engineering, UC Davis


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