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


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:

Engineering a water glass at 50 percent. Source:

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.

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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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Aquatic plants: unsung but prime salmon habitat

Photo by Carson Jeffres/UC Davis

A Chinook salmon in Big Springs Creek near Mount Shasta. Photo by Carson Jeffres/UC Davis, 2012

By Robert Lusardi and Ann Willis

For decades, California’s management and restoration of salmon and trout populations have focused on principles rooted in coastal redwood streams, mostly fed by rainfall runoff. These concepts portray ideal salmonid habitat as deep pools, shallow riffles and “large woody debris,” such as fallen trees and limbs.

Recent studies on spring-fed streams challenges this mindset. The findings strongly suggest these streams should play a larger role in the recovery and management of sensitive cold-water species, particularly salmonids.

Researchers at the UC Davis Center for Watershed Sciences found that trout in spring-fed streams grow faster than those reared in runoff streams in the same watershed.

Aquatic macrophytes in the spring-fed Shasta River. Photo by Robert Lusardi

Aquatic macrophytes in the spring-fed Shasta River. Photo by Robert Lusardi/UC Davis

Surprisingly, they suggest that trout benefit not only from the stable flow and temperature regimes of spring-fed streams but also from another dominant – yet much underappreciated – habitat feature: aquatic plants.

Known as macrophytes, these rooted vascular plants provide similar benefits as pools, and large woody debris.

As fish habitat, this woody debris provides structure, velocity heterogeneity and refuge from predators [1]. It also has been shown to increase habitat area and reduce competition between fish [2]. Similarly, biologists have long recognized pools as superior salmonid habitat for providing predator and thermal refuge, velocity heterogeneity and improved food resources [3].

Invertebrates in macrophyte habitat on Shasta River. Photo by Carson Jeffres/UC Davis

Hydopyschid caddisfly larvae spin nets to gather food in macrophyte habitat on the Shasta River. Photo by Carson Jeffres/UC Davis

Spring-fed streams generally lack the high volume flows of runoff streams that transport woody debris and scour pools. As a result, scientists and resource managers have paid less attention to the physical habitat dynamics of spring-fed systems than to other beneficial factors such as streamflow and water temperatures.

Macrophytes grow in many spring-fed streams and are largely a product of naturally occurring nutrients, stable flow and temperature, open canopy and low gradient. These plants provide many of the same benefits to trout and salmon of the more classic redwood streams type habitat.

Underwater tour of Big Springs Creek, by Carson Jeffres/UC Davis

On the Shasta River, a large spring-fed tributary to the Lower Klamath River, the UC Davis researchers conducted an experiment to understand the potential benefits of macrophyte habitat on juvenile steelhead trout.

Presented with multiple habitat types, steelhead overwhelmingly selected macrophyte habitat during spring and summer foraging. The researchers found that macrophyte habitat provided abundant food – the plants also are important for invertebrates – and refuge from high-velocity currents. This suggests that the use of macrophyte habitat allowed trout to gorge on seemingly unlimited food while exerting minimal energy.

Juvenile coho salmon in Big Springs Creek, by Carson Jeffres/UC Davis

Unlike more classic habitat forms, the effects of macrophytes on trout and salmon operate at larger spatial scales. Additional research on the Shasta River and elsewhere has shown that macrophytes increase stream water depth and wetted habitat area, and can reduce water temperature through shading [4]. Other studies have shown that macrophytes reduce competition between individual fish through visual isolation and increase fish density [5].

These broader benefits may be particularly important for salmonid populations in California during late summer and early fall, when flows in runoff streams typically decline and water temperatures rise.

Insect casings in Big Springs Creek, by Carson Jeffres/UC Davis

It’s no surprise that spring-fed streams such as Hot Creek in the eastern Sierra historically boasted some of the highest trout densities in California. Likewise, Shasta River historically supported 50 percent of the Klamath Basin’s Chinook salmon, even though it accounts for only 1 percent of the basin’s annual streamflow [6].

Pacific salmon recovery efforts in the Lower Klamath River drainage often focus on spring-fed systems such as the Shasta River because they provide flow stability and optimal thermal habitat for rearing salmonids.

While many factors contribute to fish production, macrophyte habitat has received far less attention for its beneficial effects on trout and salmon. Fully understanding such species-to-species interactions as those between plants and fish is important and will assist salmonid conservation planning and recovery.

Robert Lusardi is a post doctoral scholar in ecology at the UC Davis Center for Watershed Sciences and a California Trout-UC Davis Wild and Coldwater Fish Researcher. He studies stream ecology and food web dynamics of volcanic spring-fed ecosystems in Northern California. Ann Willis, an engineer who coordinates research programs at the Center, has done extensive fieldwork monitoring the restoration of Big Springs Creek.


[1] Crook, D.A. & Robertson, A.I. (1999) Relationships between riverine fish and woody debris: implications for lowland rivers. Marine and Freshwater Research, 50, 941-953.

[2] Sundbaum, K. and I. Naslund. 1998. Effects of woody debris on the growth and behaviour of brown trout in experimental stream channels. Canadian Journal of Zoology-Revue Canadienne De Zoologie 76:56-61.

[3] Nielsen, J.L., Lisle, T.E. & Ozaki, V. (1994) Thermally stratified pools and their use by steelhead in Northern California streams. Transactions of the American Fisheries Society, 123, 613-626; Rosenfeld, J.S. & Boss, S. (2001) Fitness consequences of habitat use for juvenile cutthroat trout: energetic costs and benefits in pools and riffles. Canadian Journal of Fisheries and Aquatic Sciences, 58, 585-593.

[4] Champion, P. D. and C. C. Tanner. 2000. Seasonality of macrophytes and interaction with flow in a New Zealand lowland stream. Hydrobiologia 441:1-12.

[5] Eklov, A.G. & Greenberg, L.A. (1998) Effects of artificial instream cover on the density of 0+ brown trout. Fisheries Management and Ecology, 5, 45-53.

[6] National Research Council (NRC). 2004. Endangered and Threatened Fishes in the Klamath River Basin: Causes of Decline and Strategies for Recovery; Wales, J. H. 1951. The decline of the Shasta River king salmon run. Bureau of Fish and Wildlife. California Division of Fish and Game

Further reading

Gregg WW, Rose FL. 1982. The effects of aquatic macrophytes on the stream micro-environment. Aquatic Botany 14: 309-324.

Beland KF, Trial JG, Kocik JF. 2004. Use of riffle and run habitats with aquatic vegetation by juvenile Atlantic salmon. North American Journal of Fisheries Management 24: 525-533.

Fausch, K. D. 1984. Profitable stream positions for salmonids – relating specific growth rate to net energy gain. Canadian Journal of Zoology-Revue Canadienne De Zoologie 62:441-451.

Jeffres, C., Aug. 24, 2011. Benefits of growing up in a spring-fed stream. California WaterBlog.

Lusardi, R. A. 2014. Volcanic Spring-fed rivers: ecosystem productivity and importance for Pacific salmonids. PhD dissertation. University of California, Davis.

Lusardi, R.A. 2013. How to save salmon: location, location, location. California WaterBlog

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Groundwater security, for the long term

Photo by Kelly M. Grow/California Department of Water Resources

Imported Colorado River percolates into Coachella Valley’s aquifer, replenishing 40,000 acre-feet of water annually. Photo by Kelly M. Grow/California Department of Water Resources

By Lauren Adams

Under recently enacted legislation, local agencies in California are required for the first time to manage groundwater pumping and recharge sustainably.

The law empowers local groundwater agencies to manage and use groundwater “without causing undesirable results,” leaving it up to them to determine how to best achieve this goal. Within the next six to eight years, agencies in groundwater basins subject to critical overdraft must adopt plans that put these areas on a path to sustainability by 2040.

A major factor complicating such long-term water planning is climate change. Failing to account for a changing climate will put agencies at risk of “undesirable results,” even if they are otherwise well prepared.

California has already experienced shifts in runoff from spring to winter. Scientists predict continued shrinking in snowpack and increased variability in temperature and precipitation, resulting in more frequent heat waves, longer droughts and more intense floods.

For groundwater, this means demand will rise in dry times, particularly for irrigation, and recharge will be less consistent. In times of water scarcity, groundwater provides more than 60 percent of water supply in some regions, compared with about 38 percent of California’s total water supply in normal years.

Modernizing and sustainably managing groundwater basins lays the foundation for climate change readiness, but more actions can be taken. The key is to make the system more reliable.

Adaptation strategies such as groundwater banking and managed aquifer recharge can help. But for the long term, to protect against more erratic water availability under climate change, a thoroughly integrated approach to water management is needed.

Groundwater basins in overdraft. Source: California Department of Water Resources, 1980

Groundwater basins in overdraft. Source: California Department of Water Resources, 1980

Managing groundwater, surface water and stormwater systems conjunctively, along with innovative water efficiency and conservation strategies, will help stabilize if not increase the amount of water available for use.

For example, Orange County Water District reports that implementing an integrated approach to water resources management allowed the district to more than double yield from their groundwater basin. Clearly defined groundwater rights make management more secure so people can trade water if they so choose.

At the least, managing for climate change will help local groundwater agencies prepare for natural climate variability. Recent analysis of tree rings in central California found that in the past 2,000 years the region often experiences periods of 14-16 years of overall wetness or dryness – a duration that exceeds many of todays’ water-planning horizons. Managing for natural variability, such as 14-16 years of below-average dryness (or, better, for droughts lasting more than 100 years as occurred in medieval California), will make it easier to manage other local problems, such as evaporative losses.

Taking a long-term approach to groundwater management will result in more resilient groundwater basins and a more secure water system for California.

Lauren Adams is a graduate student in water resources engineering and a 2014 fellow with the Integrative Graduate Education Research and Traineeship (IGERT) program at UC Davis. She was an organizer of an IGERT workshop in April on California groundwater and climate change. IGERT fellows Amanda Fencl and Katie Markovich contributed to this blog.

Further reading

California Senate Bill 1168, Senate Bill 1319, Assembly Bill 1739. Three-bill legislative package known as the Sustainable Groundwater Management Act of 2014

California Department of Water Resources. 2014. California Water Action Plan

California Department of Water Resources. 2014. “Managing an Uncertain Future”. Vol. 1, Chapter 5, California Water Plan Update 2013

California Department of Water Resources. 2014. “Conjunctive Use Management and Groundwater”. Vol. 2, Chapter 8, California Water Plan Update 2013

Groundwater Sustainability Plans: New Territory or Untrodden Ground?” Western Water Blog. Stanford University. Oct. 27, 2014

Hayhoe, Catherine, et al., 2004. “Emissions pathways, climate change and impacts on California,” Proceedings of the National Academy of Sciences (PNAS). 101 (34). 12422-12427

Hutchinson, Adam. 2014. “Conjunctive Use and Aquifer Recharge”. Presentation to CCWAS IGERT workshop, April 16, 2014

Kretsinger, Vicki, Thomas Harter and Tim Parker. “Modernizing California’s Groundwater Management”. California WaterBlog, June 22, 2014

Lund, Jay and Thomas Harter. “California’s Groundwater Problems and Prospects”. California WaterBlog. Jan. 30, 2013

Meko, David et al., 2014. “Klamath/San Joaquin/Sacramento Hydroclimatic Reconstruction from Tree Rings”. Draft Final Report to the California Department of Water Resources

Souza, Christine. “For Groundwater, Local Management Proves Effective”. AgAlert. Aug. 6, 2014

Taylor, Richard et al., 2013. “Groundwater and Climate Change”. Nature Climate Change. 3. 322-329

The Future of Groundwater in California’s Changing Climate”. Workshop organized by the Climate Change, Water and Society IGERT, UC Davis. iTunes podcasts. April 16, 2014

Upcoming Event


California’s Yolo Bypass is a grand experiment in reconciliation ecology, a new approach to species conservation.

Rather than restore the engineered Sacramento River floodplain to some natural state, scientists and conservation groups are exploring exciting possibilities for a re-engineered landscape that allows native species and human uses to coexist.

Their research indicates the floodway would make a productive salmon nursery and seasonal feeding ground for water birds at little or no cost to farmers.

The Dec. 9 symposium brings together several of the key investigators — engineers, ecologists and economists — for a daylong public discussion on how farming and floods might be reconciled with fish and fowl.

Sponsors: Delta Science Program | UC Davis Center for Aquatic Biology & Aquaculture | UC Davis Center for Watershed Sciences

Tuesday, Dec. 9,  9 am – 5 pm
UC Davis Conference Center, Ballroom B
Free and open to the public
Watch for agenda at

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Trick or treat? Aliens at the door

gobie copy

By Chris Bowman

Many of the alien species invading California’s lakes and streams would make for wickedly good Halloween costumes.

gobyTake the Shokihaze goby, Tridentiger barbatus (above and right), a native of Asian now common in Suisun Bay and the lower Sacramento River. Its spiky stubble of whisker-like barbels about the mouth and cheeks defines “ugly.” And its eyes, ringed with heavy mascara and seemingly misplaced near the top of its head, are downright spooky.

The goby’s barbels, however, are not nearly as charmless as those of the channel catfish (Ictalurus punctatus), shown below.Catfish


Then there’s the red swamp crayfish (Procambarus clarkii), aka Louisiana crawdad. Never mind the pinchers. The eyes are not only beady; they’re freakishly mounted on moveable stalks that slide independently along the side of the head. The dagger-like snout also makes this clawed carpetbagger especially hard to cuddle.

Beware Halloween night of  trick-or-treaters masquerading as freshwater aliens. If true to form, they’ll trick you even if you treat them.

didymoAlthough highly prized in Cajun cuisine, the red swamp crayfish wreaks havoc in rice fields of the Central Valley by burrowing several feet into rice checks and levees, weakening the earthen banks and causing erosion.

Another alien trickster is this microscopic algae, or diatom, to the right that looks innocently whimsical with its bottle-shaped body.

But Didymosphenia geminata (“Didymo” for short) can pull an underwater prank akin to toilet-papering your trees. It coats riverbeds with thick and slimy brown mats, choking off bottom-dwelling organisms that fish eat.

No wonder this invasive species is nicknamed “rock snot.” In the photo below, the South Fork Yuba River looks as though it has a serious sinus infection.


Rivers with stable, dam-regulated flows are particularly susceptible to infestation. Peek, who has snorkeled many California streams as a biologist with the UC Davis Center for Watershed Sciences, calls the South Fork Yuba “rock-snot Armageddon.”

He says the river sometimes looks like it is polluted with toilet paper as pieces of Didymo mats slough off and drift downstream.

Photo by Ryan Peek/UC Davis

A section of the South Fork Yuba River infested with Didymo, or rock snot. Photo by Ryan Peek/UC Davis

The Uruguay water-primrose (Ludwigia hexapetala) boasts bright yellow flowers and may be viewed as an attractive addition to California wetlands. But under the right conditions, the species grows explosively to clog waterways. Among other problems, the aquatic plant can harbor mosquitos carrying West Nile virus, as the dense patches shield the insects from pesticide spraying.

Amber Manfree, a scientist now with the UC Davis Center for Watershed Sciences, wades through a jungle of water primrose in the state Laguna Wildlife Area of Sonoma County. Photo by Julian Meisler

Amber Manfree, a scientist now with the UC Davis Center for Watershed Sciences, wades through a jungle of Uruguay water-primrose in the state Laguna Wildlife Area of Sonoma County. Photo by Julian Meisler


Microscopic view of a freshwater jellyfish collected by an angler at Lake Clementine in early October. Photo by Ryan Peek/UC Davis

The drought seems to have invited a ghostly invader to some California lakes. Earlier this month, boaters began reporting blossoms of freshwater jellyfish (Craspedacusta sowerbii) in the much depleted Lake Oroville and other diminishing reservoirs in the northern Sierra foothills.

Jana Frazier, a Department of Water Resources spokeswoman, told KNVN news of Chico that the warming low water levels “seems to trigger a good bloom of the jellyfish.” The translucent, quarter-size creature is a friendly Halloween ghost with a stinger too small to penetrate human skin.


A southern watersnake eats many different freshwater fish species such as this sunfish. The non-native snakes are invading California waters, posing a threat to native fish, amphibians and reptiles. Photo by J.D. Willson/University of Arkansas

Invasive water snakes are slithering into the Sacramento area. An estimated 300 snakes of two species — the northern or common watersnake (Nerodia sipedon) and the southern watersnake (Nerodia fasciata) — have been found in Roseville and Folsom, and at least 150 have been seen in Long Beach, according to a recent UC Davis study. Though nonvenomous, the snakes are not picky eaters. Biologists are concerned they will spread and prey on the giant garter snake and the California tiger salamander — both on the federal endangered species list — and the foothill yellow-legged frog, an amphibian of special conservation concern.

Whether slithering or slimy, ghastly or ghostly, several of California’s alien water species can be an ecological nightmare. If only they were as scared of us as we are of them.


A Shokihaze goby recently caught in Suisun Marsh. Photo by Amber Manfree/UC Davis

Chris Bowman is communications director at the UC Davis Center for Watershed Sciences. He occasionally invites freshwater aliens over for dinner, once they are cooked.

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