Keep California’s water ‘Maven’ afloat

Chis Austin, news reporter and owner of the online Maven's Notebook, a water, science and policy blog

Chis Austin, publisher of Maven’s Notebook, a blog on California water, science and policy. Photo by Betty Huey

The nonprofit Maven’s Notebook has become the daily go-to place for the latest California water news and information, including meeting summaries, keynote speeches and digests of ponderous documents. It’s a one-person operation, and that person, Chris Austin (aka “Maven”), needs your donations to stay afloat.

Helping Maven’s Notebook stay nonprofit helps everyone in California water policy and management, in at least three ways:

  • The meeting digests spare us the considerable time and expense of attending public hearings and talks
  • Maven’s water guides and seminar summaries provide free personnel training
  • Having a common, open-access source of credible, unspun information improves the quality of public debate

MavenBanner.pngMaven’s Notebook needs our collective support. Join us in becoming part of Maven’s fan club by making a monthly donation. Have your agency or firm donate more substantially, and encourage others to donate. Here is how you can help.

Now is the time for all good water wonks to come to the aid of their maven. Let’s keep this public good going.

Jay Lund, director, Center for Watershed Sciences, UC Davis
Ellen Hanak, California water policy expert

More on Chris Austin and Maven’s Notebook

Bowman C. Unmasking California’s Water ‘Maven’. California WaterBlog. March 27, 2013

Green E. In Praise of ‘Aqua Blog Maven’. Chance of Rain. Jan. 4, 2013

Matus, M. 10 Questions: Chris Austin, Water Maven. Water Deeply. Aug. 18, 2015

Posted in Uncategorized | Leave a comment

Measuring the effectiveness of ‘environmental flows’

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

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

By Ann Willis and Andrew Nichols

In the early fall of 2012, an unusually large number of Chinook salmon were returning to the Klamath River, straddling the California-Oregon border. Many of those fish were expected to swim upstream to the Shasta River, prompting emergency actions to increase stream flows in the upstream tributary.

Source: Wikimedia Commons

Klamath River system. Source: Wikimedia Commons

When Chinook enter the Shasta, they pause in pools before heading further upstream to spawn. The Shasta naturally runs low this time of year, and irrigation diversions to support the region’s cattle ranching further reduce flows.

With few fish, even low flows can provide enough pool habitat. But when large numbers return, low-flow pools fill up with fish more quickly. In these conditions, fish can rapidly deplete dissolved oxygen, even if plenty of oxygen is flowing into the pools.

In 2012 and 2013, the Shasta River Water Transaction Program worked with agricultural landowners, resource agencies, the local watermaster and others to coordinate voluntary flow contributions to support fall-run Chinook during the critical few weeks near the end of the irrigation season. It was a remarkable act of stewardship that defied the conventional farms-versus-fish showdown. But was the sacrifice of agricultural water worth it?

The benefits of such “environmental flows” are often questioned, but seldom quantified with scientific rigor. Measuring the outcomes is critical to furthering participation in voluntary agricultural and urban water transfers, particularly during dry times.

The UC Davis Center for Watershed Sciences collaborated with scientists from the Nature Conservancy and Watercourse Engineering Inc. to see if we could quantify the potential water quality risks and potential ecological benefits of the Shasta River water transfer. Could the salmon actually suffer for lack of oxygen and, if so, would the additional water from volunteers make a difference?

We found that low flows do not always pose an oxygen risk to salmon in pools, even when fish fill the pools to capacity. But when there is a problem, more water helps prevent harm to fish.

The study, recently published in the Journal of Water Resources Planning and Management, drew connections between the physical action – increasing stream flow – and ecological outcomes.

To make those connections, we defined relationships between stream flows, fish numbers, dissolved oxygen levels and habitat capacity in pools where Chinook congregate.


Summary of dissolved oxygen (DO) concentration and percent saturation with and without a 10 cubic foot per second (cfs) stream flow. Source: UC Davis Center for Watershed Sciences

First, we tested methods to quantify the amount of pool habitat available. We used rating curves, a common tool for measuring stream flows, but a new application for evaluating aquatic habitat. The method is more cost-efficient and provides more information than traditional aquatic habitat surveys. While surveys provide a few snapshots of pool habitat over weeks, the rating curve approach allows you to quantify habitat changes almost minute by minute.

We found a strong relationship between stream flow and pool volume.

Next, we looked at how changes in pool volumes affected the amount of oxygen available to fish, and whether adding water made any difference.

We found that when flows were low, water temperatures were high, and pools were filled with fish, the fish could create their own water quality impairment simply through respiration.


More stream flow means shorter travel times, moving dissolved oxygen through pools more quickly. Source: UC Davis Center for Watershed Sciences

But we were surprised to find that even a small increase in stream flow (about 10 cubic feet per second) could improve water quality by moving dissolved oxygen through the pools more quickly. Increasing stream flow also increased the size of pools to support more fish – without degrading water quality.

The implications of the stream flow experiment are extensive. Water markets, water trusts and other mechanisms compensate water-rights holders for providing environmental relief. Knowing the environmental value of water can ease tensions between competing users.

The study showed a way to quantify the environmental benefit of water contributions. This accounting method brings flexibility and transparency to a potentially contentious decision. It helps water-rights holders and resource managers decide whether fish would benefit from increased stream flows and make informed decisions about the value of their water.

Ann Willis, an engineer with the UC Davis Center for Watershed Sciences, developed this project as a consultant for Watercourse Engineering Inc. Andrew Nichols is a geomorphologist with the center.

Further reading

Willis, et al. 2015. Instream flows: new tools to quantify water quality conditions for returning adult Chinook salmon. Journal of Water Resources Planning and Management

Shasta River Water Transaction Program. Cooperating on Streamflow for Fish and Ranching in Times of Need

Holmes et al. 2013. Water transaction monitoring protocols: Gathering information to assess instream flow transactions.

Willis, et al. 2013. Water resources management planning: Conceptual framework and case study of the Shasta Basin.

Posted in Uncategorized | 3 Comments

Finally, a one-stop shop for locating California’s fishes

Source: UC Davis Center for Watershed Sciences

Introducing PISCES 2.0, an open-source software and data storage platform that uses primary source data, modeling and expert analysis to generate current and historical locations of California’s freshwater fishes. “Fish richness” is the number of different fish species in an area. Source: UC Davis Center for Watershed Sciences

By Nick Santos


The question is foundational to conservation biology and policy. To take a conservation action, you need to know where to act. And, yet, for decades stewards and researchers of aquatic fauna have been sorely lacking in tools to systematically collect, store and map data on where California’s freshwater fishes are located.

A reliable and comprehensive compilation of standardized species data is especially important for tracking California’s 133 native fishes because 100 of them are officially designated as being in trouble – “endangered” or “threatened” with extinction or otherwise of “special concern.”

This need led the UC Davis Center for Watershed Sciences to develop “PISCES,” an open-source suite of data and software providing the most comprehensive and accurate information on current and historic ranges of California’s fishes.

The center has just released PISCES to the public. The software and data can be downloaded for free from its website. The data also can be viewed from interactive maps on the website showing species ranges or species richness.

More than a data aggregator, PISCES converts different forms of data to a standard format and provides easily updatable, high-resolution maps outlining species’ ranges with the best and latest location information available. The program also produces summary California maps showing overall distribution of fishes, patterns of biodiversity and areas where biological data are lacking.

Sample range map for hardhead generated by PISCES 2.0. Source: UC Davis Center for Watershed Sciences

A sample range map generated by PISCES 2.0. Hardhead, a native California fish, are widely distributed in streams at low- to mid-elevations of the Sacramento, San Joaquin and Russian river watersheds. HUC12 or 12-digit Hydrologic Unit Code delineates sub-watersheds. Source: UC Davis Center for Watershed Sciences

Watershed Sciences researchers have already deployed PISCES on several projects, including:

A 2014 center study by Ted Grantham and co-researchers Joshua Viers and Peter Moyle is a good example of how PISCES can be used.

The scientists found PISCES invaluable for quantifying the impacts of individual dams on California’s native fishes. They needed to know with good precision the current and former ranges of imperiled species in relation to dams. This information in turn can be used to determine which dams would provide the most benefit to native fishes with improved flow releases.

PISCES enabled the researchers to flag dams in drainages known to support salmon, lamprey, splittail and other species sensitive to unnatural changes in flows. Using this filter and several others, they evaluated 753 dams on relatively large streams and rivers and identified 181 of them – 25 percent – as high-priority candidates for enforcement, under a law requiring dam owners to release enough flow “at all times” to keep fish “in good condition.”

For Moyle, a UC Davis professor emeritus of fish biology, PISCES is the culmination of several efforts to aggregate and digitize scientists’ scattered field notes and databases on locations of California fishes.

Moyle made his first attempt in the mid-1980s, to inform state fish and game wardens of the fishes likely to be affected by proposed stream alterations. He and then-graduate student Paul Randall conducted a more sophisticated cataloguing and mapping of native fish ranges in the mid-1990s as part of the Sierra Nevada Ecosystem Project, a sweeping scientific study benchmarking the ecological health of the 400-mile-long mountain range.

Species range maps can be combined to show patterns.

Species range maps can be combined to show patterns, such as “species richness”  — the number of different species in an area. Source: UC Davis Center for Watershed Sciences.

However, none of these efforts gained traction beyond the specific projects.

The turning point came in 2011. The U.S. Forest Service issued a solicitation for accurate maps of fish species locations on California’s national forests, which cover one-fifth of the state. Moyle, Viers, and graduate student Jacob Katz saw an opportunity to develop a comprehensive database.

A team of center scientists and computer programmers embarked on an extensive literature search for empirical and inferred observations of fish locations. In many cases, though, the information was stored in the unwritten memories of veteran biologists like Moyle. Researchers spent countless hours interviewing experts and poring over maps. By 2014, the group had collected 274,555 records documenting the range of California fish species.

As open-source software, PISCES allows users to enhance the tools and software and propose updates and corrections on the data. The data are available in many standard spatial and relational forms accessible from ArcGIS, QGIS, Google Earth, Microsoft Access and other software.

Although PISCES is focused on California fish, the software and database are a generalized system for tracking and analyzing ranges. It can be quickly adapted to track fauna anywhere. Scientists can install and use the software to tweak their own species ranges, export data into other formats, generate custom range maps or create ones for whole new areas or species.

Moyle said he can live easier knowing that his four decades of memories on species locations in California can be easily downloaded from a website.

“The future won’t have to rely my foggy recollections and penciled field notes,” he said. “You’ll have the database.”

Nick Santos creates geospatial applications for the UC Davis Center for Watershed Sciences and developed the PISCES software.

PISCES is the product of several current and former researchers at the UC Davis Center for Watershed Sciences, including Andy Bell, Jacob Katz, Cathryn Lawrence, Peter Moyle, Megan Nguyen, Alyssa Obester, Ryan Peek, Rebecca Quiñones, Nick Santos, Joshua Viers, Dave Waetjen and Terence Wu.

The platform was developed in partnership with the U.S. Forest Service (Region 5), California Department of Fish and Wildlife, Center for Information Technology Research in the Interest of Society (CITRIS) at UC Merced, the Nature Conservancy, California Trout and Trout Unlimited.

To learn how the software works, see the documentation or the 2014 journal article on the system.

 Further reading

Santos NR, et al. 2014. “A programmable information system for management and analysis of aquatic species range data in California.” Environmental Modelling & Software.

Grantham TE and Moyle PB. 2014. “Assessing flows for fish below dams: a systematic approach to evaluate compliance of California’s dams with Fish and Game Code Section 5937.” UC Davis Center for Watershed Sciences Technical Reports (CWS-2014-01) :1-136

Grantham TE, Viers JH, Moyle PB. 2014. “Systematic screening of dams for environmental flow assessment and implementation.” BioScience. biu159

Moyle PB and Randall PJ. 1998. California Native Fish Distributions. Environment.

Quiñones RM, et al. 2015. “Dam removal and anadromous salmonid (Oncorhynchus spp.) conservation in California.” Reviews in Fish Biology and Fisheries

Howard JK, et al. 2015. “Patterns of Freshwater Species Richness, Endemism, and Vulnerability in California.” PLoS ONE

Posted in Fish, Tools | Tagged , , , , | 7 Comments

Watering up Halloween, California style


Courtesy of Paul Duginski, political cartoonist and veteran newspaper artist in Southern California.

By Ghost Writer

What better way to spook Californians this Halloween than to appear as a slobbering “Godzilla El Niño.” Or draped in a bedsheet as Godzilla’s opponent, “The Blob,” the amoeba-shaped patch of unusually warm Pacific water blocking storms in California.

Too scary? Not to worry. Researchers at UC Davis’ Center for Watershed Sciences (publisher of California WaterBlog) suggest how you can be California-chic without egging on people’s water fears. They have no shortage of ideas for unintimidating water- and science-themed Halloween costumes. Here are some of them:


Be a trawl net, as fish ecologist Denise De Carion demonstrates. Not shown: fishnet stockings. Photo by Amber Manfree


Louie, the Center’s Lab director, as Crab Louie. Photo by Carson Jeffres

KyleKrab copy

Aquatic bug researcher Kyle Phillips competes head-on with Louie. Photo by Chris Bowman

Nothing says "Boo!" like the bug-eyed California newt with it's Halloween-orange underside. Photo by Amber Manfree

Nothing says “Boo!” like the bug-eyed California newt with its Halloween-orange hues. Photo by Amber Manfree


Rattle your neighborhood gardeners dressed as this pumpkin-orange parasite, known as dodder. Its creepy root-like organs penetrate host plants and weaken or kill them. Photo by Amber Manfree















Jay Lund

Jay Lund, the Center’s director, appears to be a Prophet of Precipitation in the monk’s robe he wore on Halloween week last year during a downpour. The Washington Post described his sign in latin as a “prayer of sorts.” It’s a play on the University of California’s motto, “Fiat Lux,” or, “Let there be light.” Lund’s sign reads “Fiat Pluvia.” Let there be rain. Photo by Chris Bowman


Posted in Halloween, Wild and Wacky | Tagged , , , , , , | 4 Comments

An update on California fishes of ‘special concern’

Salt Creek pupfish, group. Photographed at Salt Creek, CA (Death Valley National Park). Photo by Dr. Cynthia S. Shroba, College of Southern Nevada.

The Salt Creek pupfish is adapted to the shallow, hot, saline water of a particular part of Salt Creek that flows above ground year-round in Death Valley National Park. Their isolation and dependence on a single water source warrant their listing as a “species of special concern.” Photo by Cynthia Shroba, College of Southern Nevada.

By Peter Moyle

Three-fourths of California’s native fishes are now officially designated as being in trouble, or potentially so.

The good news is that not all of these species – 93 of the total 123 native fishes today – have to go the way of winter-run Chinook salmon or delta smelt, which are verging on extinction in the wild.

Years ago, state wildlife managers created a “species of special concern” designation for California fauna that are not legally classified as “threatened” or “endangered” but nonetheless appear bound for extinction without some intervention. Though the label carries no legal clout, it has brought research and management attention to these animals at risk.

To be considered a species of special concern, a fish species must be (1) declining in both geographic distribution and abundance, (2) relatively small in population and/or (3) have an extremely limited distribution.


Click on photo to download report. 

A team of fish biologists at UC Davis and the California Department of Fish and Wildlife made these evaluations and, following peer review, reported the results in the department’s recently released “Fish Species of Special Concern in California, Third Edition.”

This is the first update on the status of these fishes in 20 years, and it shows an overall continued dramatic decline in population levels. The downward trend is fundamentally tied to an increasing human demand for natural resources, especially water. Natural factors such as the current drought exacerbate the situation.

The fishes in the report are found in all regions of the state and encompass a wide range of taxonomic groups. They include obscure species with small ranges, such as Red Hills roach and Saratoga Springs pupfish, as well as the commercially valuable Central Valley fall-run and late fall-run Chinook salmon.

The High Rock Springs tui chub went out of existence in 1989, the victim of a botched attempt to farm tropical predator fish in the effluent of a desert spring in Lassen County, Calif. Photo by Dave Giordano

The High Rock Springs tui chub went out of existence in 1989, the victim of a botched attempt to farm tropical predator fish in the effluent of a desert spring in Lassen County, Calif. Photo by Dave Giordano

The previous report, published in 1995, identified 57 species of special concern. Here is what has happened to the status of those fishes:

  • 42 continue to warrant the designation
  • 11 (19 percent) were undesignated because they had been legally declared threatened or endangered
  • 3 were undesignated because their previous assessment was found to be flawed
  • 1 species went extinct – the High Rock Springs tui chub of Lassen County, Calif.

table_soscThe bottom line: Since 1995, 22 percent of the special concern species either became extinct or listed as threatened or endangered, and 21 newly evaluated fishes became species of special concern, for a total of 63.

The team of biologists based the assignment of special concern status on a systematic evaluation and subsequent peer review by experts on each species.

The scientists used information from published and unpublished sources to score each species on seven metrics: (1) area occupied (current range), (2) adult abundance, (3) intervention dependence, (4) tolerance to adverse conditions, (5) genetic risk, (6) vulnerability to climate change and (6) anthropogenic threats.

Sacramento perch, juvenile, Crowley Lake strain. Photo by Chris Miller.

Species of special concern: Sacramento perch. One of the tastiest of freshwater fishes this purple-sheened sunfish has been extirpated from its native Central Valley rivers and survives only because it has been used to support fisheries in reservoirs elsewhere in the state and the west. But one by one even these populations are dying out. Photo by Chris Miller.

A 2013 study supported the climate change determinations. On human-caused threats, the scientists analyzed the importance of 15 factors that could limit a fish species’ viability, ranging from effects of major dams to fishing.

Finally, for each species, the team rated how certain they were of their evaluations. They assigned the highest rating to those that were viewed by peers and backed by extensive surveys. The lowest rating went to those based mostly on professional judgment. Each account in the report makes recommendations for conservation actions.

chart_soscThe biologists made their approach scientific and easy to duplicate so others could independently assess the status of fishes using the same process. This approach also makes it easier to change status as new information becomes available. Using the same methods for future status reports will make it easier to determine the overall success or failure of conservation efforts.

Many fishes currently listed as threatened or endangered started out as species of special concern. The species evaluations in the report indicate that is not an inevitable pathway, provided protective action is taken soon.

Given that 64 percent of California native fishes are found only in California, their continued decline is a truly California problem, needing solutions by Californians.

Peter Moyle, a UC Davis professor emeritus of fish biology, led the Fish Species of Special Concern in California study with the help of his former graduate students, Rebecca Quiñones and Jacob Katz, and Jeff Weaver, a fisheries biologist with the California Department of Fish and Wildlife.

Further reading

Moyle P.B., J. D. Kiernan, P. K. Crain, and R. M. Quiñones. 2013. Climate change vulnerability of native and alien freshwater fishes of California: a systematic assessment approach. PLoS One

Moyle, P. B., R. M. Yoshiyama, J. E. Williams, and E. D. Wikramanayake. 1995. Fish species of special concern of California. California Department of Fish and Game, Sacramento, California. 2nd ed. 272 pp

Posted in Fish | Tagged , , , | 2 Comments

Capturing El Niño for the underground

Orchards of walnuts (above) and almonds (below) may be viable sites for groundwater recharge, though the potential for water damage to such high-value crops adds risk.

University of California scientists recently identified 3.6 million acres of California cropland suitable for replenishing the state’s groundwater reserves, which are at a record low. Walnut orchards may be  viable sites for groundwater recharge, though the potential for water damage to such high-value crops adds risk. Photo by David Doll

By Philip Bachand, Helen Dahlke, William Horwath, Thomas Harter and Toby O’Geen

A much-anticipated “Godzilla” El Niño this winter may refill California’s drought-diminished reservoirs, but it won’t do much to restock the severely depleted aquifers we rely upon to get by during droughts.

The California Department of Water Resources (DWR) recently reported that groundwater levels across most of the state have dropped 50 feet below historical lows, with levels in many areas of the San Joaquin Valley more than 100 feet below previous record lows. Source: DWR

The California Department of Water Resources (DWR) recently reported that groundwater levels across most of the state have dropped 50 feet below historical lows, with levels in many areas of the San Joaquin Valley more than 100 feet below previous record lows. Source: DWR

One reason for this is the sheer depth of California’s precipitation deficit – the deepest of any drought in 120 years of recordkeeping. The state has been drier than normal for 10 of the past 14 years.

The above-average amount of pumping during all those dry years has led to the deepest groundwater levels ever recorded in most areas of the state. In some areas water tables have plummeted by more than 100 feet. Unlike surface water reservoirs, aquifers do not refill with just one or two wet years, no matter how big the El Niño

A strong El Niño nonetheless presents a precious opportunity to replenish some of these vital underground reserves faster than would otherwise occur.

California’s vast acreage of irrigated farmland holds the key. Using the existing irrigation network, we can capture flood flows from our rivers onto suitable dormant or fallow agricultural fields, allowing the surplus water to infiltrate aquifers.

A team of University of California scientists has already identified 3.6 million farm acres with soils most conducive to groundwater recharge – those with high percolation rates. They developed an interactive map where growers can obtain site-specific information on the suitability of soils for on-farm recharge.

In other words, more than one-third of the state’s nearly 10 million acres of irrigated cropland could potentially be re-purposed as groundwater infiltration basins during winter and early spring – outside the usual growing season.

Likewise, the same infrastructure that conveys about 20 million acre-feet of water to irrigate California crops during the growing season could be used to divert high river flows onto fields in the off season, mimicking natural floodplains.

UC researchers recently developed a soil suitability index for groundwater recharge on cropland, based on such factors as (A) deep percolation, (B) root zone residence time and (C) chemical limitations. Source: UC Davis California Soil Resource Lab 

During storms and flood-control releases, excess river water could be routed through irrigation canals onto farms, where the surplus would seep underground to replenish groundwater. This action could also mitigate downstream flood risks.

Farmers stand to benefit from this off-season arrangement. The infiltration of floodwaters  would restore the drought-depleted soil moisture in crop root zones while accelerating recharge of regional aquifers. Greater availability of groundwater saves farmers the high expense of pumping deeper and drilling more wells.

California Agriculture journal, July - September 2015, Volume 69 number 3.

Changes in groundwater storage in the Central Valley (dark blue) and its subregions, 1922-2009 . The largest depletions have occurred in the Tulare Lake Basin, which includes the southern Valley from Fresno to Bakersfield. Source: Thomas Harter/California Agriculture. (Adapted from Brush 2014)

Researchers with UC Davis and UC Agriculture and Natural Resources and their team of consultants are working to bring this new drought management and groundwater banking strategy into the mainstream. They have been test-flooding a number of vineyards, almond orchards and other cropland recently, looking at infiltration rates, plant physiology, groundwater quality and costs. So far, results look promising.

To take advantage of a strong El Niño this winter, farmers would need to determine how much floodwater they would want to divert and when they would want it. This would depend on the crop, soil preparation and planting dates, the soil moisture status and other agronomic considerations.

Dam operators and irrigation district managers also would need to make a number of strategic determinations, including:

  • The amount of investment needed for diverting and distributing flood flows into irrigation systems
  • Where that investment would reap the greatest benefits in groundwater and soil moisture replenishment
  • Whether to postpone wintertime maintenance of diversion and distribution systems to accommodate floodwater delivery
  • The type and level of incentives and outreach needed to gain landowner participation.

Jim Morris, a Siskiyou County rancher shown here, opened his alfalfa field last spring to UC researchers who are testing the groundwater recharge potential in various croplands around the state. “It was amazing to see how well the land absorbed the water and how quickly the water table rose,” Morris told UC Davis News. Photo by Steve Orloff.

Farmers and water managers should make preparations now to reap the most benefits of the predicted winter storms, including:

  • Identify fields and crops suitable for winter and early spring flooding
  • Minimize fall applications of fertilizers and pesticides to protect groundwater quality
  • Do your irrigation canal repairs and clearance this fall, before the storms
  • Clarify water rights as they pertain to capturing and applying large amounts of floodwater to cropland

To be sure, groundwater banking on farmland is several big steps away from becoming widespread. Several agronomic, policy and institutional questions remain to be investigated.

But flooding just 10 percent of the state’s irrigated cropland a few feet deep this winter would result in an additional 3 million acre-feet of groundwater. That’s half of the additional 6 million acre-feet of groundwater that California farmers are expected to pump this drought year to offset the drastic shortfall in surface water deliveries.

After four years of drought, a statewide effort by farmers, government agencies and water districts to capture flood flows to replenish our depleted groundwater is needed to seize what is expected to be rare opportunity – a monster El Niño.

Philip Bachand is an environmental engineering consultant in Davis. Helen Dahlke, William Horwath, Thomas Harter and Toby O’Geen are on the faculty at UC Davis’ Department of Land, Air and Water Resources.

Further reading

Agricultural Groundwater Recharge and Banking. Project Website. UC Davis. Posted October 2015

Alvarez, Felicia. Yolo farmers bank water for the future. The Davis Enterprise. Oct. 14, 2015

Bachand P, Horwath WR, Roy SB, Choperena J and Cameron D. 2014. “Implications of using on-farm flood flow capture to recharge groundwater and mitigate flood risks along the Kings River , CA.” Environmental Science & Technology. 48 (23), pp 13601–13609 DOI: 10.1021/es501115c. Nov. 13, 2014

Dahlke HE. Summary of on-going research activities on groundwater banking on cropland. UC Davis Department of Land, Air and Water Resources, UC Davis

Howitt R, MacEwan D, Medellín-Azuara J, Lund J, Sumner D. “Economic analysis of the 2015 drought for California Agriculture”. Center for Watershed Sciences, UC Davis. August 2015

Flooding farms in winter may help replenish groundwater”. UC Davis news release. Sept. 9, 2015

Flooding farms in winter may help replenish groundwater”. UC Davis news release. Sept. 9, 2015

Khokha S. “How flooding fields could alleviate water supply stress.” KQED. March 29, 2013

O’Geen AT, et all. 2015. “Soil suitability index identifies potential areas for groundwater banking on agricultural lands.” California Agriculture. 69(2):75-84. DOI: 10.3733/ca.v069n02p75.April-June 2015.

Quinton A. “Flooding California farmlands might restore groundwater.” Capital Public Radio (Sacramento). Sept. 22, 2015

Swain D. “El Nino now among strongest in modern history”. California Weather Blog. Oct. 8, 2015

Posted in Drought, El Niño | Tagged , , , , , , , , , | 6 Comments

Urban water conservation for the birds

Butte Sink Wildlife Management Area. Photo by U.S. Fish and Wildlife Service

Sacramento Valley’s Butte Sink Wildlife Management Area. U.S. Fish and Wildlife Service

By Jay Lund

People who save water like to know their conserving is doing some good, such as sustaining economic growth, building municipal reserves for longer droughts or supporting the environment.

But many urban residents are concerned their water savings will go to uses they value less — such as supplying more wasteful customers, new urban development or agriculture — rather than meeting the needs of fish, waterbirds and other wildlife, which they value more. In fact, most household water conservation does free up water for other local users or eases State Water Project and Central Valley Project supplies for other thirsty cities or farms, rather than go directly to environmental protection.

For households interested in conserving water for environmental purposes, a bargain might be struck. The table below lays out how people might be motivated to use less water knowing that much of their savings would be dedicated to a favored environmental cause, such as supporting wildlife refuges.                           

Water Conservation for the Birds — Who Does What?table_waterbirds.png

Wildlife refuges seem the most suitable place to begin such voluntary environmental water transactions. Water management for refuges is generally more structured and precise than for fish and have more developed assessments of how their water use affects wildlife. Refuges also are better tied into the water supply system, making it easier to move water to wetlands most in need.

Urban water savings would make major, measurable improvements at refuges, where a little goes a long way.

Sacramento National Wildlife Refuge. Photo by U.S. Fish and Wildlife Service

Sacramento National Wildlife Refuge. U.S. Fish and Wildlife Service

Central Valley refuges use about 600,000 acre-feet a year for waterbirds and other critters, compared with a statewide net urban water use of about 6.6 million acre-feet a year — about half for landscape irrigation. So a 10 percent savings in urban water use, or a 20 percent reduction in landscape watering, could roughly double water for wildlife refuges.

Such a program would better define and publicize the ties between local water use and the health of California’s ecosystems. Once urban water customers see their conservation efforts making a difference, they will likely be motivated to make further savings.

If successful for wildlife refuges, it could be expanded to fish and other environmental purposes, creating wildlife and recreational assets and empowering environmental water management.  We could make water conservation for the birds, and for the fish.

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

Further reading

Lund J and Moyle P. “Water giveaways during a drought invite conflict“. CaliforniaWaterBlog. March 23, 2015

Lund J. “New environmentalism needed for California water“. CaliforniaWaterBlog. Dec. 9, 2014

Lund J, et al. “Why give away fish flows for free during a drought?” CaliforniaWaterBlog. Feb. 11, 2014

Hanak, E., et al. “Managing California’s Water: From Conflict to Reconciliation“, Public Policy Institute of California, San Francisco, CA, 500 pp., February 2011.

Posted in Water Conservation | Tagged , , | 8 Comments

Time-lapse river videos expose nature in the raw

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Video surveillance helps tell the story of rivers in the Sierra Nevada. This frame shows the confluence of the Tuolumne and Clavey river downstream of Yosemite National Park during a storm on Feb. 7, 2015. Source: UC Davis Center for Watershed Sciences

By Ryan Peek


A group of science teachers from senior and junior high schools participating in the Center for Watershed Science’s Tuolumne River Institute hike along the wizened North Fork of the Tuolumne River, which was reduced to puddles in the fourth summer of severe drought. Photo by Ryan Peek, July 2015

Thanks to its Mediterranean climate, California swings from one extreme to another — severe drought, raging wildfires, big floods. These forces often interact and amplify, as we saw all too well this past summer in the scorching of hundreds of thousands of extremely dry forested acres, with the loss of homes and lives. Big floods could be just around the corner, if predictions of a “Godzilla El Niño” hold true.

Researchers with the UC Davis Center for Watershed Sciences watch these dramas play out in several rivers of the Sierra Nevada. As part of a long-term river monitoring project, we track changes in streamflow, temperature and structure of river channels. We also regularly collect data on fish diversity, native frog breeding and the diversity and abundance of aquatic invertebrate.

The data are useful for linking physical and ecological processes, but they don’t always tell the whole story.

Game Cameras

Researchers mount game surveillance cameras on riverside trees to take hourly pictures of Sierra rivers. Source: UC Davis

A few years ago we began to get a fuller picture after installing a number of small time-lapse cameras at key locations within our monitoring sites. Typically used by hunters for game surveillance, these rugged weatherproof devices are programmed to take a picture every hour.

We compile the photos into time-lapse videos and can overlay river data collected at the same location.

Hydrograph curves showing changes in streamflow take on new meaning when matched with corresponding videos, as shown below. We can see what a daily change of, say, 600 cubic feet per second actually looks like in a river.

Note during winter storms how much muddier the river turns in 2015, compared with 2012. The 2013 Rim fire accounts for the difference. This was the largest Sierra fire in more than a century of recordkeeping. It burned 257,314 acres (400 square miles), much of it within the Tuolumne River watershed. With rain and higher flows, sediment from hill slopes can be mobilized and flushed into the river. The loss of trees from the fire amplified this effect, creating less stable soil in the steep river canyon. 

Hydrographs and videos of Tuolumne-Clavey confluence

1. January – July 2012


2012 hourly discharge on Tuolumne River at Wards Ferry in cubic feet per second (cfs). Source: U.S. Geological Society, gauge 11285500

2. January – July 2015


2015 hourly discharge on Tuolumne River at Wards Ferry in cubic feet per second (cfs). Source: U.S. Geological Society, gauge 11285500

Documenting changes in river systems and comparing them over time is key to understanding the ecological impacts of fires, floods and droughts.

Tuolumne_Watershed_v4Fire and floods beget erosion and mudslides, clouding waterways with high loads of sediment. High stream flows help “reset” river ecosystems by scouring vegetation, moving sediment and forming new habitat.

Many native California organisms depend on such diverse and dynamic river processes. Dynamism promotes biodiversity.

Videos of the Tuolumne-Clavey confluence are particularly instructive. They capture events before and after the Rim fire. The blaze felled the tree that held our camera, but the device remained attached to the trunk and continued to take pictures and ground level, as shown in this video narrated by Watershed Sciences researcher Eric Holmes:


A thick mantle of silt cover a cobble bar in the Tuolumne River following winter storm in 2015. The 2013 Rim fire cooked the soil in parts of the watershed, creating a high potential for erosion and runoff. Photo by Ryan Peak, May 2015.

The drought has minimized the post-fire erosion in the Tuolumne River canyon. Still, with only moderate rain, you see significant increases in turbidity and sedimentation. Visiting the monitoring site this past May, we found a foot or more of silt along the banks.

Heavy sedimentation can have major impacts on native aquatic species such as the foothill yellow-legged frog. The frogs attach their egg masses to rocky substrates in sheltered slow-moving waters of rivers and creeks. The females lay only a single egg cluster a year, so the loss of these breeding grounds to heavy sedimentation can significantly diminish reproductive success. 

Foothill yellow-legged frog. Photo by Ryan Peek

A rare foothill yellow-legged frog finds part of its breeding habitat on the Tuolumne River smothered in silt. Photo by Ryan Peek, May 2015

Similarly, the eggs of salmon and trout require constant flow through their gravel nests to supply enough oxygen for their development. Sedimentation can also smother bottom-dwelling macroinvertebrates, an important food source for many species.

At the same time, the buildup of sediment can provide new areas for riparian vegetation to take hold.

Ironically, the banks of the Tuolumne and Clavey rivers are noticeably lusher these days because of the Rim fire and drought. The post-fire sedimentation and lack of high flows to flush the drought-stricken rivers have allowed riparian vegetation to gain traction.

Time-lapse videos show changes in riparian vegetation on the Clavey River before (2012) during (2013) and after (2015) the Rim fire. Heavy sedimentation following the fire allowed plants and trees to take root. Source: UC Davis Center for Watershed Sciences

Time-lapse videos show changes in riparian vegetation on the Clavey River before (2012) during (2013) and after (2015) the Rim fire. Heavy sedimentation following the fire allowed plants and trees to take root. Source: UC Davis Center for Watershed Sciences

Time-lapse videos help us understand the ebb and flow of rivers we study. They make it apparent how dynamic these systems can be. They also show the power and importance of fires and floods in creating, maintaining and changing habitat for fish, amphibians and other aquatic life.

Ryan Peek is a doctoral student in ecology at UC Davis.

Further resources

Animated map of Rim fire (Video, ~1 min.). Open Data City. September 2013

Santos N. 2014. “Remote Sensing, Event-Based Monitoring and Change Detection Using Off-the-Shelf Hardware” (Video, ~13 mins). UC Davis Center for Watershed Sciences. April 30, 2014

Time-lapse videos of Sierra Nevada rivers (Videos). UC Davis Center for Watershed Sciences

Data on stream temperatures and stages. UC Davis Center for Watershed Sciences

Boxall B. Rim fire’s effects likely to last for decades to come“. Los Angeles Times. Sept. 23, 2013

Jeffres C, Peek R, Ogaz M. “Journey to the bottom of the Rim fire“. California WaterBlog. Sept. 26, 2013

Park H, Cave D, Andrews W, Canepari Z. “After years of drought, wildfires rage in California“. New York Times. July 15, 2015

Swain D. “California fire season explodes“. California Weather Blog. Aug. 4, 2015

Viers J and Santos N. 2014. “Hydrolapse Videography: A Coupled Hydroinformatic Stack for Improved Visual Assessment of River Dynamics“. 11th International Conference on Hydroinformatics. HIC 2014. New York City.



Posted in Tools, Tuolumne River | Tagged , , , , | 4 Comments

The banality of California’s ‘1,200-year’ drought

The south fork of Lake Oroville, California's second largest reservoir, in September 2014. Photo by Kelly M. Grow/California Department of Water Resources.

The south fork of Lake Oroville, California’s second largest reservoir, in September 2014. Photo by Kelly M. Grow/California Department of Water Resources

By Jay Lund

California’s ongoing drought will continue to break records and grab headlines, but it is unlikely to be especially rare from a water policy and management perspective.

Estimates of the current drought’s rarity range from once in 15 years to once in 1,200 years (Griffin and Anchukaitis 2014), depending on the region and indicators used (precipitation, stream runoff, soil moisture or snowpack). In the Middle Ages, large parts of California had droughts far worse than this one, some lasting more than a century (Stine 1994). The probability of California experiencing a once in 1,200-year drought during a short human lifetime is extremely low.

The chance that this dry period is a “new normal” is probably small. Many parts of Australia are paying for expensive desalination plants built when a severe drought was misinterpreted as a new normal. If this drought is as unusual as once in 1,200 years, then why pay heed beyond just getting through it? We are unlikely to see the likes of it again.

The obsession over El Niño and the California drought masks the reality that the atmospheric condition is poorly correlated with stream flows in Northern California, where 75 percent of the state’s water supply originates.

East Coast news media should keep this perspective: Every summer California has a drought far drier and longer than the eastern U.S. has ever seen. This explains California’s extensive water and irrigation infrastructure (and why people move to California).

Distressed vineyard in Coachella Valley on July 10th 2014.

Drought-stressed vineyard in Coachella Valley in July 2014. Photo by Kelly M. Grow/California Department of Water Resources

The uniqueness of an individual drought is fascinating. Each drought is unique in area, persistence, dryness, temperature, internal pattern and how it ends. California’s current drought is unusually severe, and certainly the worst since 1988-1992. Groundwater in the Tulare basin is probably lower than at any time in human history. This drought also has been unusually warm, leading to it having the lowest snowpack in 500 years and driest soil in 1,200 years. In precipitation and flows on major rivers, the 2012-2015 drought so far ranks between the third and eighth driest years on record.

By focusing on unique aspects of a drought, any drought can become an incredibly rare event. Becoming engrossed in the superlatives, however, can distract from the business of managing water shortages and preparing longer-term solutions.

What’s more relevant for water policy and management is the banality of drought. We should expect to see droughts in California of severity similar to the current drought about once or twice in a generation. Given climate change and the growth in expectations and values for diverse water uses, it seems reasonable to expect such droughts a bit more frequently than in the past. The warmer temperatures in this drought seem likely to become normal for future droughts, with disproportionate effects on ecosystems and small streams.

Lake Oroville's Bidwell Marina in September 2014. Photo by Kelly M. Grow/California Department of Water Resources

Lake Oroville’s Bidwell Marina in September 2014. Photo by Kelly M. Grow/California Department of Water Resources

Agencies, cities, bankers, insurers, farmers and residents should prepare for greater regularity of droughts as harsh as the current one. Severe drought in California should be reclassified from a rare “act of God” to something more like a business cycle swing that recurs several times in a lifetime or career.

California is managing pretty well under the current drought in most areas (Howitt et al. 2015; Hanak et al, 2015) and can survive much more severe and prolonged droughts, if managed well (Harou et al, 2010).

It is more important to focus on managing the dry event and preparing for future ones than understanding the fascinating intricacies of drought origins and statistics. But we probably will continue to obsess about drought statistics and El Niño anyway.

Further reading

Belmecheri S, Babst F, Wahl ER, Stahle DW and Trouet V. (2015). “Multi-century evaluation of Sierra Nevada snowpack.” Nature Climate Change.

Cayan D and Mount J. “Don’t count on El Niño to end the drought.” Viewpoints/The PPIC Blog. July 9, 2015

Griffin D and Anchukaitis KJ. (2014), “How unusual is the 2012–2014 California drought?Geophys. Res. Lett., 41, 9017–9023, doi:10.1002/2014GL062433

Hanak E, Mount J, Chappelle C, Lund J, Medellín-Azuara J, Moyle P and Seavy N. What If California’s Drought Continues? 20 pp. PPIC Water Policy Center, San Francisco, CA, August 2015

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

Howitt R, MacEwan J, Medellín-Azuara J, Lund J. “Drought bites harder, but agriculture remains robustCaliforniaWaterBlog. Aug. 18, 2015

Howitt R, Medellín-Azuara J, MacEwan D, Lund J and Sumner D. (2015). “Economic Analysis of the 2015 Drought for California Agriculture.” Center for Watershed Sciences, UC Davis. 16 pp. August 2015

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

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

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

Stine S. (1994). “Extreme and persistent drought in California and Patagonia during medieval time“. Nature, 369, 546–549, doi:10.1038/369546a0

Posted in Drought, Planning and Management | Tagged , , | 5 Comments

How research programs stack up — a photo essay

By Jay Lund

Riding into work the other day, I was thinking how our understanding of hard problems requires understanding a lot of pieces and how those pieces fit together – sort of like how a pile of bricks gets transformed into a habitable structure.

If every research study is a brick in our understanding, how would research programs stack up?

Most research programs

1. Most research programs. 


2. Some of the better agency research programs.

Lightweight bricks stack easier

3. Lightweight studies stack easier.

Many studies are colorful, but not strong

4. Many studies are colorful, but not strong.


5. A common tenure package.


6. Building from different brick types and shapes is difficult, but often necessary.

7. Often research must move forward creatively

7. Often research must move forward creatively. 

8. What we wanted

8. What we wanted.

Often the best we can do

9. Often the best we can do.

Photo credits: (1) Jeff Stvan/Flickr Commons, (2) Simon Bratt/Depositphotos, (3) Jack Two/Flickr Commons, (4) Derek Bruff/Flickr Commons, (5) Glyn Lewis/Depositphotos, (6) Tim Abbott/Flickr Commons, (7) Buzzhunt, (8) Google Maps, (9) Dave Herholz/Flickr Commons


Posted in Wild and Wacky | Tagged , | 4 Comments