Delta smelt’s unsung cousin seems verging on extinction, too


The longfin smelt, so-named for its long pectoral fins, lives in the open water of San Francisco Estuary. Source: U.S. Bureau of Reclamation

By James Hobbs and Peter Moyle
Another native fish of the Sacramento-San Joaquin Delta appears to be rivaling the cliffhanger status of the delta smelt.

Relative to its historical abundance, the lesser-known longfin smelt has experienced an even bigger decline than delta smelt — and may be in bigger trouble — according to trawl surveys of Delta fishes.

In the past two years, catches of adult longfins have been close to zero, and a recent larval survey found alarmingly few of the smelt. The dramatic downturn is likely a result of the drought, as with the tinier delta smelt.

Lacks federal protection

Unlike its headline-grabbing relative, the longfin is not listed under the federal Endangered Species Act.

In 2012 the U.S. Fish and Wildlife Service determined that the Delta population of longfin smelt deserved protection, but designated the fish only as a candidate for listing. The less powerful California Endangered Species Act lists the species as threatened with extinction. Presumably, the federal protections for the delta smelt have benefited the longfin and other native fishes because it is the species most sensitive to changes in the Delta’s waterways.

The longfin and delta smelt were once common, thriving inhabitants of the Delta and elsewhere in the open waters of San Francisco Estuary. The longfin live two to three years longer than the delta smelt and grow twice as big – up to 5 inches long – big enough to have been an important part of the San Francisco Bay commercial smelt fishery in the 19th century.


Longfin smelt grow up to 5 inches, about twice the length of nature delta smelt. Photo by Randall Baxter/California Department of Fish and Wildlife

The longfin population was the most abundant fish in the upper estuary. The population has gone through several boom and bust periods (Figure 1).

The initial slump, in the 1980s, was at least partially the result of the invasion of the overbite clam, which has robbed pelagic fish of food. Starting in 2002, the population nosedived, following the trajectory of delta smelt and other species — a trend known as the Pelagic Organism Decline

Sampling programs all show population collapsing

Before 1980, the state’s Fall Midwater Trawl survey alone would catch thousands of individuals in a four-month season (September-December). Since 2002, only 10 – 100 fish have been captured per season.

A similar pattern is shown in the San Francisco Bay Study, a monthly fish survey that uses midwater and bottom otter trawls to sample from South San Francisco Bay to the North Delta. Together, the state surveys show a dramatic decline of longfin smelt throughout the estuary (Figure 2).

Likewise, our monthly sampling in Suisun Marsh, which UC Davis began in 1979, has shown a long-term decline of the smelt (Figure 3).

siderTom Cannon, an estuarine fisheries ecologist and biostatistician, was perhaps the first to sound the alarm over the estuary population of longfin smelt, in a recent California Fisheries Blog headlined, “They’re Gone.” 

Are they on the verge of extinction? The answer is not as clear as it seems to be for delta smelt, in part because so much less is known about longfin.

Recent UC Davis surveys have found longfin smelt in areas not previously monitored — Alviso Marsh in the lower South Bay, Napa-Sonoma Marsh, Petaluma River and the Cache-Lindsey Complex of the North Delta — raising the question of whether the smelt’s distribution has changed.

While the species clearly is in severe decline, it is possible that sampling programs are missing significant segments of the population. In summer and fall, substantial numbers inhabit coastal waters — outside areas surveyed.

However, all sampling programs within the estuary show longfin of all ages collapsing in the past few years,  suggesting an estuary-wide decline.

Drought impacts

The aggressive invasion of the overbite clam in San Francisco Estuary is blamed as one of the causes of the decline of delta and longfin smelt in recent years. Photo by Cynthia Brown/U.S. Geological Survey

The aggressive invasion of the overbite clam in San Francisco Estuary is blamed as one of the causes of the decline of delta and longfin smelt in recent years. Photo by Cynthia Brown/U.S. Geological Survey

The abundance of longfin smelt, particularly young-of-year, increases with the amount of freshwater flowing through the estuary (Figure 4). The fish also seems to have a low tolerance for warmer waters, with adults rarely found in water warmer than 64 degrees (18 degrees C) and young-of-year above 73 degrees (22 degress C) [Figure 5].

Warmer temperatures and less freshwater flow in the Delta are associated with drought, so if the drought continues, longfin smelt are likely to be extirpated from the estuary. Even if the drought ends, smelt numbers may be so low that recovery will be difficult and slow.

Recolonization from more northern populations is possible but highly uncertain, reflecting a need for more research on the basic biology of the species. We just hope the smelt will still be around to study.

James Hobbs is a research scientist and Peter Moyle if a professor of fish biology, both with the UC Davis Department of Wildlife, Fish and Conservation Biology. This article originally posted Aug. 31, 2015 and revised Sept. 1 with additional information and sources.

Further reading

Hobbs, J. A., C. Parker, J. Cook and M. Bisson. 2015. Technical Report: The distribution and abundance of larval and adult longfin smelt in the San Francisco Bay tributaries Year 1: Pilot Study. DOI: 10.13140/RG.2.1.3185.5843

Hobbs, J.A., L. L. Lewis, N. Ikemiyagi, T. Sommer and R. Baxter. 2010. “The use of otolith strontium isotopes (87Sr/86Sr) to identify nursery habitat for a threatened estuarine fish.” Environmental Biology of Fishes. 89:557-569. DOI 10.1007/s10641-010-9762-3

Merz, J.E., P.S. Bergman, J. F. Melgo and S. Hamilton. 2013. Longfin smelt: spatial dynamics and ontogeny in the San Francisco Estuary, California. California Fish and Game 99(3):122-148

Rosenfield, J. A. and R. Baxter. 2007. Population dynamics and distribution patterns of longfin smelt in the San Francisco Estuary. Transactions of the American Fisheries Society 136:1577-1592


Figure 1.  Fall Midwater Trawl Survey abundance indices for most common Delta fishes, 1967 – 2014. (Axes scaled to abundance of longfin smelt, with breaks in y-axis for less abundant species) Source: California Department of Fish and Wildlife


The longfin and delta smelt were once abundant in the Delta and elsewhere in the open waters of San Francisco Estuary. The longfin live two to three years longer than the delta smelt and grow twice as big – up to 5 inches long – big enough to have been an important part of the San Francisco Bay commercial fishery in the 19th century.

Figure 2.  Abundance indices (standardized) for longfin smelt, 1980 – 2014. Source: California Department of Fish and Wildlife 


Figure 3. Catch-per-minute otter trawling Suisun Marsh, 1980 – 2014. Source: UC Davis



Longfin smelt abundance in the Fall Midwater Trawl (log transformed) plotted against freshwater outflow (log transformed). Regressions lines for the 1967-1987 pre-Corbula years, 1988-2000 Corbula invasion period, and from 2002-2014 “modern-climate regime”. Corbula is an invasive clam that has reduced the food supply for longfin smelt and other pelagic species.

Figure 4.  Longfin smelt abundance in Fall Midwater Trawl plotted against Delta freshwater outflow (log transformed). Regression lines for 1967 – 1987 (pre-overbite clam invasion); 1988 – 2000 (during invasion); and 2002 – 2014 (post-invasion). The invasive overbite clam has robbed food from longfin smelt and other pelagic species. Source: California Department of Fish and Wildlife

Smoothed presence-absence data from the San Francisco Bay Study (Otter trawl + midwater trawl) for Age-0, Age-1 and Age-2 longfin smelt occurrence with water temperature. (data 1980-2013)

Figure 5.  Smoothed presence-absence data of longfin smelt — Age 0, Age 1 and Age 2 –with water temperature, 1980 – 2013. Source: San Francisco Bay Study (otter and midwater trawls) 



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Guidance for putting new groundwater law on the ground


Groundwater fills irrigation ditch on a Kern County cotton field in the 2015 drought. Photo by Chris Austin/Maven’s Notebook

By Thomas Harter, Vicki Kretsinger Grabert and Tim Parker

A group that helps shape California groundwater policy has proposed several ideas for state consideration in implementing the 2014 Sustainable Groundwater Management Act (SGMA).

The Contemporary Groundwater Issues Council of the Groundwater Association of California – comprised of various agency executives and influential water researchers and consultants – weighed in on three major issues the California Department of Water Resources (DWR) will face in the next 18 months as it drafts the law’s regulations and guidelines:

  • Criteria for DWR evaluation of Groundwater Sustainability Plans (GSPs)
  • Best Management Practices (BMPs) for sustainable groundwater management
  • Tools and technologies that DWR needs to provide to local Groundwater Sustainability Agencies (GSAs) for effective implementation of the law.

The council developed the recommendations earlier this summer after inviting officials at DWR and the State Water Resources Control Board to present their ideas and plans for the law’s implementationScreen Shot 2015-08-26 at 10.33.22 PM.png

1. Evaluating sustainability plans

By mid-2016, DWR will have set regulations on the evaluation and implementation of GSPs (Figure 1 below). The council addressed several topics relevant to drafting those rules, mainly:

  • How to assess: (1) appropriateness of a GSP, (2) metrics for measuring success, (3) integrating the required 50-year planning horizon and (4) public outreach and stakeholder engagement in the GSP process
  • How to address cross-basin boundary challenges

Council members’ concerns included:

  • Making regulations sufficiently flexible for a highly variable and somewhat subjective process while being firm on attaining sustainability goals
  • Some regions missing the mandatory deadline for completion of GSPs because they were politically challenged and slow to form GSAs.
  • DWR’s ability to provide GSAs the technical assistance needed to develop acceptable plans
  • Lack of adequate data in some basins to prepare adequate GSPs
  • Timeliness of DWR’s GSP reviews
  • Constitutional restrictions imposed by California’s Proposition 218 – a 1996 voter-approved initiative – may impede GSA financing

Evaluating GSPsScreen Shot 2015-08-26 at 10.35.17 PM.png

2. Best Management Practices for achieving sustainability

The law requires DWR to publish Best Management Practices (BMPs) by Dec. 31, 2016. Issues for consideration include:

  • Infrastructure approaches to increase recharge and decrease groundwater demand
  • Assessment of BMPs’ effectiveness
  • Data needs
  • Technical/financial/regulatory support to advance implementation of programs and practices
  • Outreach and education

Concerns include:

  • How regulations would address data confidentiality
  • Availability of technical assistance to facilitate effective implementation of BMPs
  • Standardizing data collection, monitoring and modeling/assessment to ensure attainment of basin objectives without being overly prescriptive
  • Quality assurance and control (QA/QC) in data collection, reporting and assessment
  • Availability and adequacy of staff and expertise

Best Management PracticesScreen Shot 2015-08-26 at 10.41.39 PM.png

3. Tools and technologies for effective implementation

The success of the new groundwater law depends in part on providing local agencies useful tools and technologies for developing and implementing the GSPs.

For economies of scale it may be more advantageous that the state provide the big data tools. These would include INSAR (Interferometric Synthetic Aperture Radar) to evaluate the effects of groundwater extraction on land subsidence; SEBAL (Surface Energy Balance Algorithm for Land) for mapping evapotranspiration; and other remote sensing and advanced monitoring techniques. The state also has basin-wide models that can be improved and used for water budgeting and to verify sub-basin and other area-specific models.

The council raised some of the same concerns as in topic 1 and 2 – cost, balance of flexibility vs. effectiveness, need for data QA/QC and lack of data – plus one more: Losing coherency and transparency in data collection by dispersing the effort among too many agencies. The concern is over local agencies’ willingness to share data and conform to electronic formats compatible with statewide databases.

Tools and TechnologiesScreen Shot 2015-08-26 at 10.37.43 PM.png

Thomas Harter is a groundwater specialist with the UC Davis Center for Watershed Sciences. Vicki Kretsinger Grabert is president of Luhdorff & Scalmanini Consulting Engineers in Woodland, Calif., and Tim Parker is president of Parker Groundwater in Sacramento. Harter and Parker are on the board of directors of the Groundwater Resources Association of California and Grabert is a former board member.

Figure 1: Summary of SGMA regarding DWR regulations for GSPs
Screen Shot 2015-08-26 at 10.01.29 PM.png

Figures 2: Excerpts from SGMA on best management practices and assessment of water available for groundwater replenishmentScreen Shot 2015-08-26 at 9.53.32 PM.png

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Drought bites harder, but agriculture remains robust

50-Line-between-the-planted-and-unplanted copy

Irrigation ditch divides a vineyard and unplanted field near the Fresno County town of Huron, on the west side of the San Joaquin Valley. Photo by Chris Austin of Maven’s Notebook

Spanish version

By Richard Howitt, Duncan MacEwan, Josué Medellín-Azuara and Jay Lund

Today we release our second annual report estimating the economic impacts from prolonged drought.

More than anything, the results of our 16-page analysis of the current growing season speak to agriculture’s remarkable resilience to multiyear surface water shortages. They also show that the industry’s ability to continue growing in revenue and jobs is coming at increasingly higher costs.

Overall, California’s $46 billion-a-year agricultural output remains robust in this fourth year of severe drought, mostly because of the state’s vast reserves of groundwater. Drawing on these reserves will replace an estimated 70 percent of the surface water shortage this year, compared with a 75 percent offset in 2014.


Source: Economic Analysis of the 2015 Drought on California Agriculture, executive summary

Continued strong global demand has driven high prices for many of California-grown fruits, nuts and vegetables also has helped sustain the farm economy along with water transfers and shifts in growing locations.

Our survey of more than 70 irrigation districts earlier this summer and spring indicates an increase in water transfer activity over the previous year. The average water transfer price is more than $650 an acre-foot, compared with $500 an acre-foot in 2014. Water transfers and shifts in crop contracts can significantly temper the economic impacts of drought throughout the Central Valley, particularly on perennial fruit and nut orchards and grape vines and higher-value vegetables.

These factors are having their largest effect in the Sacramento Valley. Strong prices have shifted contracts for tomatoes grown for canning north, from the San Joaquin Valley to areas in the Sacramento Valley with better access to water. In addition, farmers statewide have been moving from field crops to higher-value almonds and walnuts, with more than 200,000 acres of new orchards planted since 2010.

Taken together, these adjustments blunt much of the economic blow of drought to agricultural communities and food consumers.

That said, several small rural communities continue to suffer from high unemployment and drying up of domestic wells because of the drought, particularly in the Tulare Basin.

Further, the heavy reliance on groundwater comes at ever-increasing energy costs as farmers pump deeper and drill more wells. Some of the heavy pumping is in basins already in severe overdraft, inviting further land subsidence and water quality problems, and diminishing reserves needed for future droughts.

If the drought persists beyond 2015 at its current intensity, California’s agricultural production and employment will face further reductions.

As with our 2014 analysis, this year’s study was prepared at the request of the California Department of Food and Agriculture using computer models and the latest estimates of surface water availability from state and federal water projects and local water districts.

Our key findings:

  • The total impact of the 2015 drought to all economic sectors is an estimated $2.74 billion, compared with $2.2 billion in 2014. About $1.84 billion of that are drought-related costs to the agriculture industry. (The state’s farmers and ranchers currently generate more than $46 billion annually in gross revenues, a small fraction of California’s $1.9 trillion-a-year economy.)
  • The loss of about 10,100 seasonal jobs directly related to farm production, compared with the researchers’ 2014 drought estimate of 7,500 jobs. When considering the spillover effects of the farm losses on all other economic sectors, the employment impact of the 2015 drought more than doubles to 21,000 lost jobs.
  • Surface water shortages will reach nearly 8.7 million acre-feet, which will be mostly offset by increased groundwater pumping of 6 million acre-feet.
  • Net water shortages of 2.7 million acre-feet will cause roughly 542,000 acres to be idled – 114,000 more acres than the researchers’ 2014 drought estimate. Most idled land is in the Tulare Basin.
  • The effects of continued drought through 2017 (assuming continued 2014 water supplies) will likely be 6 percent worse than in 2015, with the net water shortage increasing to 2.9 million acre-feet a year. Gradual decline in groundwater pumping capacity and water elevations will add to the incremental costs of a prolonged drought.

The state’s new groundwater law requiring local agencies to attain sustainable yields could eventually reverse the depletion of underground reserves. The transition will cause some increased fallowing of cropland or longer crop rotations but will help preserve California’s ability to support more profitable permanent and vegetable crops during drought.

Overall, our results show California agriculture faring much better this year than many had predicted.

In a recent commentary for the New York Times, journalist Charles Fishman observed that, “amid all the nervous news, the most important California drought story is the one we aren’t noticing. California is weathering the drought with remarkable resilience.”

We agree.

Richard HowittJosué Medellín-Azuara and Jay Lund are researchers with the UC Davis Center for Watershed Sciences. Duncan MacEwan is with ERA Economics of Davis, Calif. They co-authored the report, “Economic Analysis of the 2015 Drought for California Agriculture,” which was released Aug. 18, 2015.

Downloads of 2015 report:

Further reading

Fishman C. (2015). “How California is Winning the Drought.” New York Times. Aug. 14, 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

Howitt R, Medellín-Azuara J, MacEwan D, Lund J and Sumner D. (2014). “Economic Analysis of the 2014 Drought for California Agriculture.” Center for Watershed Sciences, UC Davis. 20pp

Howitt R, Medellín-Azuara J, MacEwan D, Lund J. (2014). “Weathering the drought by drawing down the bank.” California WaterBlog. July 15, 2014

Lund J. (2014) “Could California Weather a Mega-Drought?California WaterBlog. June 29, 2014

Medellín-Azuara J. (2015). “Drought killing farm jobs even as they grow.” California WaterBlog. June 8, 2015

Medellín-Azuara J. (2015). Jobs per drop irrigating California crops.” California WaterBlog. April 28, 2015

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

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The hard work of sustainable groundwater management


Groundwater users in the Main San Gabriel Basin clashed with downstream users as the region transitioned from citrus groves to sprawling suburbia. The competing interests eventually worked out a court-approved agreement over pumping rights after a series of difficult and exhausting negotiations. Photos: San Gabriel Valley in 1900 and in modern times. Sources: Covina Citrus Industry Photographs, Covina Public Library; Wikipedia 

By Erik Porse

Under California’s new groundwater law, local agencies must adopt long-term plans for sustainably managing basins subject to critical overdraft. Preparing these plans will be challenging, requiring collaboration and compromise among water users accustomed to pumping as they please.

Local agencies do not know exactly what they’re in for. They’ve never been responsible for achieving “sustainable groundwater management,” as the law requires. However, the histories of adjudicated basins in the Los Angeles area can be instructive. They illustrate the difficult and exhaustive process required in reaching agreement among unregulated groundwater pumpers.

Beginning in the late 1940s, as the post-war suburban boom was taking off, several water utilities and landowners in Southern California turned to the courts to settle disputes over groundwater pumping rights.

Two factors helped the parties reach long-term agreements approved by the courts and codified into law.

First, imported water from the expanding Metropolitan Water District of Southern California (MWD) allowed water users to set less restrictive limitations on groundwater pumping, because additional water was available to the basins.

Second, water users had to learn to communicate and negotiate before deciding how to allocate pumping rights. They did this first through informal working groups, and then through formalized institutions and regulations. The groups had to make a long series of decisions in financing engineering assessments of safe yield, negotiating with MWD for imported water and dealing with neighboring basins affected by their pumping.

The Long Beach Judgment

The making of a 1965 groundwater agreement known as the Long Beach Judgment is particularly illustrative. The settlement governs groundwater flows between the “Upper Basin” (Main San Gabriel Basin) and the “Lower Basins” (the Central and West Coast groundwater basins) of Los Angeles County. Carl Fossette, a lead player in the negotiations, recounted the talks in a short 1986 book, “The Story of Water Development in Los Angeles County.”


Map by Megan Nguyen/UC Davis and Eric Porse/UCLA

Rapid urbanization and prolonged drought in the 1940s put these basins into severe overdraft, where groundwater use greatly exceeded the amount that could be replaced.

Water users in the Lower Basins had spent millions of dollars supplementing and recharging their groundwater supply with imported Colorado River water from MWD. Those in the Upper Basin, however, had no plans to curtail pumping or buy imported water, and had done little to replenish groundwater.

The disparity grated on water users in the Lower Basins because most of their natural groundwater replenishment comes from the Upper Basin, via underground flows through Whittier Narrows. The two sides had to come to terms with the groundwater overdraft to sustain the region’s rapid growth.

Water users organized informally

The Central Basin Water Association took the first step by inviting major Upper Basin users to meet with Lower Basins users in January 1955. The upstream users, in turn, formed the Upper San Gabriel Valley Water Association, headed by Robert Radford, the mayor of Monrovia and a local water expert. Fossette describes their first office as a dingy house “nestled up to a gas station, heavily populated with crawling things which defied eviction.”

Most upstream association members pushed to form a municipal water district and annex to MWD. However, the cities of Alhambra, Azusa, Monterey Park and Sierra Madre broke away to form their own group and avoid contracting with MWD.

Frustration grew in the Lower Basins. In 1958, the Long Beach Water Department sued Upper Basin users for allegedly causing their water tables to drop and sought a determination of upstream users’ water rights.

Lawyers, consultants kept at bay

Early talks among lawyers and engineers were unsuccessful. Then, in 1960, each side formed five-member “lay” negotiating committees, excluding technical and legal staffs in favor of representatives from cities and water associations.

Many of the lay committee members knew each other from other dealings. Professional staff and consultants remained on the sidelines. The technical experts did jointly develop what became the “basic reference book” throughout negotiations, but only occasionally attended talks on a “speak-when-spoken-to” basis.

Negotiators met monthly through early 1961 to produce a breakthrough deal guaranteeing underground flows from the upper to lower basins. The talks then moved to details. Key figures helped secure trust and bridge gaps.

Trusted officials narrowed disputes

Fossette was particularly well positioned for this role, being general manager of water districts in both the upper and lower basins. He was eventually invited to participate in the negotiations.

On Sept. 11, 1963, Fossette instigated a marathon effort to work out an agreement. Negotiators met at the new Edgewater Inn in Long Beach with the intention to “stay there until we reach agreement” (Fossette 1986: 191).

The chairman of the Lower Basins committee walked out on the first day. But negotiations soon resumed:

“After early breakfasts, talks extended until lunch, followed by sessions until dinner hour. Even at the dinner hour, the participants were busy discussing strategy. This schedule of negotiating and wrestling with problems continued for several days. After each session, it was necessary for Fossette and (Ruth) Getches to redraft and retype the documents which had been amended, or simply reworded, and agreed upon” (Fossette 1986: 191-92).

After four exhausting days, the parties checked out of the hotel with a solid pact, later validated by Los Angeles County Superior Court. It was a critical step in securing a region-wide strategy for long-term groundwater management in the county.


Groundwater levels in the Main San Gabriel Basin are measured regularly to track fluctuations in water usage and conservation. The San Gabriel Valley Water Association designed this widget to promote water conservation.

Negotiating groundwater agreements today

As pumpers in basins throughout California develop sustainability plans, they may ponder important considerations for groundwater management today that the Los Angeles area settlements did not address.

For instance, those agreements do not consider water for fish and other environmental uses, even though surface waters and groundwater are closely linked. The adjudications also are silent on water quality. Underground contaminant plumes today affect how the court-appointed watermasters manage groundwater in adjudicated basins.

Southern California groundwater agreements are regarded as models of environmental governance. They formed the basis of a 1965 dissertation by the eminent social scientist Elinor Ostrom, which described how small- and medium-sized groups are able to develop collective agreements that can preserve natural resources. That work led to decades of international research on environmental governance that won her the Nobel Prize for Economics in 2009.

Yet, past results do not guarantee future victories. Local water interests have much hard work to do with late nights and cold pizza before California can declare success in managing its groundwater responsibly.

Erik Porse is a postdoctoral researcher with the Institute of the Environment and Sustainability at UCLA. 

Further reading

Blomquist W. A. (1992). Dividing the Waters: Governing Groundwater in Southern California. ICS Press

Fossette C. and Fossette R. (1986). The Story of Water Development in Los Angeles County. Central Basin Municipal Water District. Los Angeles, CA.

Hardin G. (1968). The Tragedy of the CommonsScience 162.3859 (1968): 1243-1248

Lund et al. (2015). Creating effective groundwater sustainability plans. California WaterBlog. March 4, 2015

Ostrom E. (1965). Public Entrepreneurship: A Case Study in Ground Water Basin Management. PhD dissertation. UCLA

Ostrom E. (1990). Governing the Commons: The Evolution of Institutions for Collective Action. Cambridge University Press

Porse E., Glickfeld M., Mertan, K., Pincetl, S. (2015). Pumping for the masses: evolution of groundwater management in metropolitan Los Angeles. GeoJournal. doi: 0.1007/s10708-015-9664-0

California’s Sustainable Groundwater Management Act

The Long Beach Judgment. Board of Water Commissioners of the City of Long Beach, et al, v. San Gabriel Valley Water Company et al, Los Angeles County Case No. 722647. Judgment entered Sept. 24, 1965

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Napa County strings together a ‘living’ river


Black-necked stilts hunt in restored Napa River mudflats. Recent habitat improvements have rapidly attracted desirable native species such as these to the downtown area. Photo by Amber Manfree, July 28, 2015

By Amber Manfree

In the historic heart of Napa Valley, a moderate climate and alluvial soils deposited by the Napa River create perfect conditions for world-class cabernets. An acre of vines here sells for around $300,000, or 25 times the state average for irrigated cropland.

Yet a group of landowners have ripped out 20 acres of these prized vineyards to make room for river restoration, with levee setbacks, terraced banks and native plants.

The project runs the length of Rutherford Reach, a 4.5-mile stretch of the Napa River between St. Helena and Oakville. Landowners say the changes will bring economic benefits over the long term by reducing crop losses from floods and plant disease. Most of all, they feel good about giving back to the river that has brought them so much.

Rutherford Reach is one several sites undergoing major habitat and flood control improvements on the Napa River. Some projects started more than 40 years ago. Others are just getting off the ground.

Far from postage-stamp restorations, these efforts are steadily transforming a huge swath of wetlands in a very lived-in area, re-establishing geomorphic function at the landscape scale.

Innovative funding, inclusive planning and adaptive management power these projects and offer lessons for river restoration elsewhere.

With the completion of ongoing projects, tens of thousands of acres and about 60 percent of the Napa River’s length will have been rejuvenated with improved habitat, intact geomorphic function and reconnected floodplains. Map by Amber Manfree/UC Davis

With the completion of ongoing projects, tens of thousands of acres and about 60 percent of the Napa River’s length will have been restored with improved habitat, intact geomorphic function and reconnected floodplains. Map by Amber Manfree/UC Davis

Here’s a closer look at three major flood control and river rejuvenation projects on the Napa: Rutherford Reach, downtown Napa and the lower Napa River:

Rutherford Reach: a landowner-­initiated restoration

For decades, landowners along the Rutherford Reach struggled with bank instability and floods. The river was confined to create more space for vineyards while upstream dams reduced sediment delivery, leading to incision and eventually lowering the riverbed six to nine feet.

Without a healthy stream profile, desirable river processes and species were lost. Invasive plants such as giant reed and Himalayan blackberry overtook the banks, further degrading habitat and hosting problem insects. 

Then, in 2002, a group of influential vintners organized as the Rutherford Dust Society approached Napa County about partnering to restore the reach, and a new path to restoration unfolded. The landowners:

  • Led the initiative and were involved throughout the planning process
  • Are making meaningful contributions of land and money
  • While motivated in part by economic considerations, they find conservation to be its own reward

More than two dozen landowners support the $20 million restoration and its long-term maintenance, each paying an annual fee based on the linear feet of river crossing their property. Altogether, the landowners will contribute about $2 million over 20 years. The project also is supported with $12 million from a county bond measure and $7.7 million in state and federal grants.

County partnership gives landowners better control over the spread of Pierce’s disease, a grapevine-damaging bacterium spread by sharpshooter insects, said Jeremy Sarrow, a specialist with the Napa County Flood Control and Water Conservation District.

A section of Rutherford Reach, before and after restoration. Source: Napa County Resource Conservation District

A section of Rutherford Reach, before and after restoration. Source: Napa County Resource Conservation District

The county can accommodate landowner requests for removal of riverside plants that host the disease, an action requiring a state Department of Fish and Wildlife permit. The agency generally does not grant these river modification permits to private landowners. Also, the State Water Resources Control Board requires landowners in this reach to show how their land management controls the amount of fine sediment entering the river, and participating in restoration can earn them a waiver.

Importantly, the landowner funding supports long-term monitoring of restoration, with any excess rolled into an interest-bearing fund for unexpected maintenance costs.

County staff have spent 10 years monitoring the transition from degraded to restored riparian corridor, revising techniques as they go. If something isn’t working – invasive weeds are popping up, a log jam blocks fish passage, an herbicide kills non-target species – the corrections can be made in the field, and landscape processes continue in the intended direction instead of backsliding.

With the first 4.5 miles of riparian corridor construction wrapping up, project managers are preparing to restore 9 more miles just downstream between Oakville Cross Road and Oak Knoll (See map). Together, these projects will transform habitat along 25 percent of the river’s 55 miles.

Downtown Napa: Redesigned flood control revitalizes city core

Napa was built on a particularly flood-prone site: a broad plain at the confluence of the Napa River and Napa Creek -- a flood hazard in its own right. The city center also is on the neck of an oxbow, the river's overflow valve during floods. Further, the buildup of water here is compounded by incoming tides, which push was upstream. Source: Google Earth

Napa was built on a particularly flood-prone site: a broad plain at the confluence of the Napa River and Napa Creek, which is a flood hazard in its own right. The city center also is at the downstream end of the neck of an oxbow, the river’s overflow valve during floods. The buildup of water here is compounded by incoming tides, which push water upstream.

At least 22 serious floods have inundated Napa since 1865, which means locals have been sandbagging their doorways once every seven years or so since the town was on the map. These days, a revolutionary flood control project is reshaping the city center.

In the mid-1990s, the community rebuffed an Army Corps proposal to dredge, straighten and armor the banks of the Napa River. Stakeholder disagreement and funding gaps had hindered flood control throughout the 1900s, but this time things were different.

Residents insisted on a design that improves the environment and makes the river a focal point of downtown. Agencies responded by assembling a community coalition of many residents, local nonprofits, the Army Corps and county flood control officials. The group engaged in a lengthy planning effort and developed a “living river” design. The plan was to accommodate both floods and the environment by removing armored banks and reconnecting the river to its historical floodplain.


Jeremy Sarrow of the Napa Flood Control District leads a recent tour of the Napa River restoration for the UC Davis Center for Watershed Sciences. The stepped floodwall doubles as an amphitheater in downtown Napa. Photo by Stacy Han/UC Davis

Fifteen years later, 7 miles of the downtown reach have been transformed both visually and functionally.

The confluence of Napa Creek and the Napa River has been extensively reshaped, providing space for floodwaters and improved conveyance. Native plants such as tules, alders and willows stabilize banks.

Meticulously engineered placement of woody debris has made the streams more hospitable for salmon and steelhead trout. Napa Creek overflow channels as wide as boxcars are buried under streets.

Seven bridges and two railroad trestles have been reconstructed at higher levels and dozens of buildings have been torn out to make way for the river.


The 2002 photo on left shows the Hatt Building, an abandoned 19th century storehouse, and a more recent warehouse perched on a steep bank with poor quality habitat. Today, the Hatt is an upscale shopping and dining destination protected by floodwalls with a sculpture garden promenade and the warehouse has been removed to give the river room to handle bigger flows. Photos by Caetlynn Booth (L) and Amber Manfree.

Capacity-increasing overflow basins and the enormous Oxbow bypass look and function like parks when water is at normal levels. The parks, which connect to riverside walking and biking trails, are used for community events year round.

In all, planners estimate they have tripled the river’s capacity while improving habitat and bolstering the local economy. The Army Corps views the effort as a pilot project for flood-prone communities.

The lower Napa: steady, strategic land acquisitions for conservation

At the mouth of the Napa River, a vast wetland complex has quietly become the second-largest tidal restoration project in California, after the South Bay Salt Pond Restoration Project near San Jose. The reserve system grew steadily over the past 40 years, eventually encompassing more than 35,000 acres of wetlands encircling San Pablo Bay.

San Pablo Bay National Wildlife Refuge, one of the oldest of the reserves, now spans more than 10,000 acres near the mouths of the Napa River and Sonoma Creek. Building on this foundation, the Land Trust of Napa County along with county and state agencies have strung together properties along 12 miles of the Napa River to extend the reserve system north from Mare Island to Napa. Today, this network provides habitat, recreation and increased flood capacity. 

In addition, tidal flows are returning and marshes are renewing themselves across 13,000 acres of former salt evaporation ponds and hayfields on the north shore of San Pablo Bay, now part of the state-managed Napa-Sonoma Marshes Wildlife Area.

The South Napa Wetlands Opportunity Area, 1,200-acre component of the flood control project, ties the downtown improvements with the downstream string of estuarine wetland reserves. Breached and lowered levees give floodwaters a safe place to spread out, increasing flood capacity and conveyance downtown and reconnecting the river to its floodplain and tidal marsh.

Both habitat and geomorphic function are being restored throughout the lower Napa River. With every additional levee breach, the area is increasingly hydrologically connected to the San Pablo Bay region.

Rejuvenating a sense of place

Each of these restoration efforts was driven by communities with a strong sense of place and an appreciation of the environment, along with a practical need for flood control and a societal imperative to bring back the salmon.

With the completion of ongoing projects, tens of thousands of acres and about 60 percent of the Napa River’s length will feature improved habitat, intact geomorphic function and reconnected floodplains.

With experience gained through adaptive management, project managers are increasingly skilled in restoring landscape processes. The accrued knowledge will be an asset to future work.

Residents await the next big flood with a new attitude, less afraid and more curious to see how well the redesign will perform. The Federal Emergency Management Agency is revising flood risk zones to reflect improvements, which will lower insurance rates for many.

Years of field surveys will be needed to assess restoration project outcomes for the river’s other residents: the birds, fishes and mammals. Judging by appearances, habitat is already much more appealing to wildlife.

Pond turtles, ducks, geese, and egrets are common within a few steps of First and Main streets in downtown Napa. Beavers have recolonized surprisingly fast, felling newly planted cottonwoods and building dams at the Rutherford Reach and even on Napa Creek just off Main Street.

The definitive test will be what happens with native salmon and steelhead, as hopes for their return have guided much of the habitat restoration.

Amber Manfree, a native of Napa County, is a geographer and postdoctoral researcher with the UC Davis Center for Watershed Sciences. She co­-edited the 2014 book, Suisun Marsh: Ecological History and Possible Futures.”

Further reading

Fimrite P. 2011. “Napa River restoration project serves as model.” San Francisco Chronicle. Dec. 10, 2011

Napa River/Napa Creek Flood Protection Project, Napa County

Photo Gallery: Napa River Flood Protection Project: Hall Building to First Street. MGE Engineering Inc of Sacramento

Napa River Flood Protection Project: Hatt Building to First Street, Napa, CA, MGE Engineering Inc. of Sacramento

Rutherford Dust Society



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Ten realities for managing the Delta

Levee break on Upper Jones Track, June 3, 2004. State Department of Water Resources.

Levee break on Upper Jones Track, June 3, 2004. Photo: California Department of Water Resources.

This article was originally published Feb. 26, 2013

By Peter Moyle

I have been working on Delta fishes for nearly 40 years. Increasingly, I have curmudgeonly thoughts about what is needed to make the ecosystem work better. Here I present these thoughts as “Ten Realities” – statements of the obvious that are often overlooked in public debates about the system.

Reality No. 1:  The historical Delta ecosystem cannot be restored. The Delta of today bears almost no resemblance to the Delta of 100 years ago. Late 19th century residents would have a hard time recognizing the place.

Gone are the tule-filled flood basins and marshes. Hardly a trace of riparian forest remains. Only 3 percent of the historical wetland acreage exists today. About the only familiar features would be the main sloughs and river channels, and even they have high levees on both sides (Whipple et al. 2012).

What this means is that Delta ecosystem cannot be restored to look or function as it did at some idyllic point in the past. Too much has changed for that to happen. How do you bring back tule or cattail marsh to an island that has sunk 30 feet from decades of farming its peaty soil? You can’t. How do you reverse the dominance of alien plants and animals in the Delta? You can’t (Lund et al. 2007, 2011).

Reality No. 2:  The Delta is not one place. Ecologically, the Delta is at least three places: the North Delta, the Central Delta and the South Delta.

Each place is distinctly different in the extent, distribution and characteristics of historical habitat types – tidal wetlands, waterways, lakes and ponds, and riparian forest – as detailed in a recent investigation of the Delta’s ecological history (Whipple et al. 2012). Although the habitats have been dramatically altered, differences in habitat types still hold today.

The differences are important in deciding where habitat improvements will have the best chance of success. The North Delta, for example, is where farming is likely to be sustained indefinitely – and where some of the biggest opportunities for habitat restoration exist. (Moyle et al. 2012). The Central Delta, in contrast, is most likely to change to open water as the result of floods, rising sea level and earthquakes (Lund et al. 2010).

Reality No. 3:  All species are not equal. Traditionally, habitat restoration efforts have aimed to recover populations of all native species – rare or not – by creating reserves or parks with restrictions on development. The approach is noble, but it rarely works in aquatic ecosystems. That’s because human activities have already transformed most systems beyond the point they can be meaningfully restored (Reality No. 1).

We should have ecosystems that contain as many California endemic species as possible. But preservation is a demanding enterprise. It requires intensive management of human-dominated ecosystems that contain mixtures of native and non-native species. We humans decide by our actions which of these species are desirable and worth preserving, often without making a conscious choice.

For example, if we want a Delta sport fishery, we should emphasize striped bass rather than largemouth bass. They’re both alien predators, but striped bass need an estuary.  If you’re managing for striped bass, you’re more likely to have an estuary that also happens to be good habitat for most native fishes. Keep in mind, though, that the Delta is not homogenous (Reality No. 2). Largemouth bass might be best suited for deeply subsided regions, which may never accommodate natives well.

Reality No. 4:  We know a lot about the Delta. “We need better science,” or, “We don’t know enough,” are common rationales for staying the course on Delta management. In reality, the Delta is part of the world’s most studied aquatic ecosystem, the San Francisco Estuary.

Environmental scientists have been steadily taking pulse of the estuary for more than 50 years, be it water quality, fish populations or volume of inflows. The Biennial Bay-Delta Science Conference consistently draws hundreds of researchers. There is even a scientific journal devoted exclusively to the estuary.

I agree that there is never enough information to make decisions with absolute certainty. But we have a lot of information today to guide restoration efforts (Healey et al. 2008; Lund et al. 2010). We have to be willing to take the risk that some decisions made today will be wrong, or at least not exactly right, in retrospect.

Steamboat on the San Joaquin River, circa 1860, with field of tules on fire. Mount Diablo in background. James M. Hutchings, Scenes of Wonder and Curiosity in California

Steamboat on the San Joaquin River, circa 1860, with field of tules on fire and Mount Diablo in background.  From  Scenes of Wonder and Curiosity in California by James M. Hutchings.

Reality No. 5:  The Delta will change dramatically, no matter what. When interest groups say they want to protect the Delta, they essentially mean they want to protect the status quo. They think of the orchards, the row crops and the levees as constants, as with the largemouth bass fishery and the winter cornfields full of sandhill cranes and swans.

But the Delta has always been changing, especially in the past 150 years (Reality No. 1). Dramatic, rapid  change is in its future (Lund et al. 2007; Lund 2011). An earthquake, giant storms and/or sea level rise will transform much of the estuary into open water.

This is not hyperbole. Levees give way even in the absence of extreme events. It was a calm and sunny day in June 2004 when a 350-foot section of levee on the Jones Tract west of Stockton collapsed, flooding farmland and sending officials scrambling to restore the levee and pump out the island.

Reality No. 6:  Island flooding is a mixed bag for native fish. Flooded islands at intertidal elevations can create more habitats for some native fish, as the flooding of Liberty Island demonstrates.

Levee breaks and flooding of deeply subsided islands in the south and central Delta will create lakes that favor non-native fish and invertebrates. But with the right flows, salinity and temperature, flooded islands also could support desirable plankton-feeding fishes such as young striped bass and delta smelt (Moyle 2008).

Reality No. 7:  Climate change will alter the Delta ecosystem. Regional climate change is likely already affecting the magnitude, timing, duration and temperatures of flows to the Delta.

The projected increase in frequency and magnitude of winter floods will increase pressures on levees and the likelihood of widespread, multi-island floods, particularly in the south and central Delta. Also, many levees will not be able to sustain climate-induced sea level rise, which is projected to be 1 to 1.5 meters by the end of this century.

Longer periods of drought, another predicted effect of climate change, would result in more fresh water being captured for humans and less flowing through the Delta for fish. In dry years, temperatures may reach levels lethal for native fishes such as delta smelt (Brown et al. 2011). Thus, many native fishes in the Delta may not survive under climate change (Moyle et al. 2012). But if we plan for climate change – for example, use cold water storage of upstream reservoirs combined with the cool, deep pools in the subsided delta – we we may be able to create conditions for most of these fishes to make it.

Reality No. 8:  Alien species cause major ecosystem changes. The Delta is part of the most “invaded” estuary in the world.  The pace of invasions appears to have increased in recent decades. At least 185 alien species of aquatic and terrestrial plants and animals now inhabit the Delta. They have profoundly changed Bay-Delta food webs and habitats, mostly (but not always) to the detriment of native species.

Two of the bigger ecological troublemakers are the Brazilian waterweed (Egeria densa) and the overbite clam (Potamocorbula amurensis). With densities as high as 10,000 per square meter, the dime-size clams suck up enormous amounts of plankton, robbing Delta smelt and other pelagic fish of food. Meanwhile, dense patches of the prolific Brazilian waterweed are slowing tidal flows and creating lake-like conditions favorable to bass, sunfish and other non-native fish.

Reality No. 9:  A Delta that is variable in time and space will be best for native fish. We’ve transformed the Delta from a highly variably ecosystem favored by native fish to a lake-like environment with more uniform habitats.

If we want native fish in the future, we need to reintroduce variability on a large scale. Variability means a wider range both in the conditions of the water – temperature, salinity and turbidity – and in habitat types  – tidal wetlands, waterways, lakes and ponds, and riparian forest (Moyle et al 2010).

Reality No. 10: Accomplishing “coequal’ goals in the Delta means greatly improving conditions for fish. The 2009 Delta Reform Act mandates that the state achieve the “coequal goals” of providing a more reliable water supply for California and protecting, restoring and enhancing the Delta ecosystem.

The reality is that the water priorities for people and fish and have never been anything approaching equal. The environment has always gotten the short end of the stick.

So achieving coequal goals should mean greatly improving conditions for fish, first, and then figuring out how to share the water better. It means we should give far greater consideration to native and other desirable species in the way we release water from dams and move it through the Delta.

In my gloomier days, I think “co-equal goals” really means just slowing the native fishes’ slide towards extinction, so we can say, “Well, we tried.” But fundamentally I am an optimist. I like to think of a rosier future for the Delta ecosystem under the rubric of “reconciliation ecology” (Rosenzweig 2002).

This means we accept the fact that all species live in human-dominated ecosystems, and that we must make those systems as welcoming as possible for the desirable (mostly native) species. This means greater integration of natural processes into the management of all areas, whether cities, farms, wildlands or waterways.

This will not be easy. But I love to think of the Delta as the first place in California where reconciliation ecology is applied on a large scale.

Peter Moyle is a UC Davis professor of fish biology and an associate director of the university’s Center for Watershed Sciences.

Further reading

Brown LR, Bennett W, Wagner RW, Morgan-King T, Knowles N, Feyrer F, Schoellhamer DH, Stacey MT, Dettinger M. 2011. Implications for Future Survival of Delta Smelt from Four Climate Change Scenarios for the SacramentoSan Joaquin Delta, California. Estuaries and Coasts  DOI 10.1007/s12237-013-9585-4

Healey, et al. 2008. The State of Bay-Delta Science 2008, CALFED Science Program, Sacramento, CA.

Lund (2011), “Sea level rise and Delta subsidence—the demise of subsided Delta islands,”, March 9, 2011.

Lund J, Hanak E, Fleenor W, Howitt R, Mount JF, Moyle PB.  2007. Envisioning Futures for the Sacramento-San Joaquin Delta, Public Policy Institute of California, San Francisco, CA.

Lund J, Hanak E, Fleenor W, Bennett W, Howitt R, Mount J, Moyle PB, Comparing Futures for the Sacramento-San Joaquin Delta, University of California Press, Berkeley, CA, February 2010.

Lund J, Moyle PB, Hanak E, Mount JF, “No going back for the Delta, but which way forward?”,, June 22, 2011.

Moyle PB. 2002. Inland Fishes of California, Revised and Expanded. Berkeley: University of California Press. 502 pp.

Moyle, PB. 2008. The future of fish in response to large-scale change in the San Francisco Estuary, California. Pages 357-374 In K.D. McLaughlin, editor. Mitigating Impacts of Natural Hazards on Fishery Ecosystems. American Fishery Society, Symposium 64, Bethesda, Maryland.

Moyle PB, Bennett W, Durand J, Fleenor W, Gray B, Hanak E, Lund J, Mount JF. 2012. Where the wild things aren’t: making the Delta a better place for native species. San Francisco: Public Policy Institute of California. 53 pages.

Moyle PB, Lund J, Bennett W, et al. 2010. Habitat Variability and Complexity in the Upper San Francisco Estuary. San Francisco Estuary and Watershed Science 8(3):1-24.

Moyle PB, Quiñones RM, Kiernan JD. 2012b. Effects of climate change on the inland fishes of California, with emphasis on the San Francisco Estuary region. California Energy Commission, Public Interest Research Program White Paper CEC-500-2011-037. 211 pp.

Rosenzweig, ML. 2003. Win-win ecology: how the earth’s species can survive in the midst of human enterprise. Oxford: Oxford University Press.

Whipple AA, Grossinger RM, Rankin D, Stanford B, Askevold RA . 2012. Sacramento-San Joaquin Delta Historical Ecology Investigation: Exploring Pattern and Process. Prepared for the California Department of Fish and Game and Ecosystem Restoration Program. A Report of SFEI-ASC’s Historical Ecology Program, SFEI-ASC Publication #672, San Francisco Estuary Institute-Aquatic Science Center, Richmond, CA.


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Is California’s drought a ‘new normal’ ?

From left,  Mark Cowin (DWR Director) and Governor Edmund G. Brown Jr. address the media during a snow survey at Phillips Station on April 1, 2015.  Measurements in Phillips began in 1942, and today is the first time there is zero snow for an April 1 measurement.  Below-normal precipitation, combined with unusually warm weather, has produced meager snowfall during the traditional wet season. *FOR EDITORIAL USE ONLY*

Gov. Jerry Brown addresses the media at a snowless snow survey site just south of Lake Tahoe on April 1, in the fourth year of drought. On his left is Mark Cowin, director of the California Department of Water Resources (DWR). Photo by Florence Low/DWR

By Stephen Maples

Many are wondering whether the current drought is the harbinger of a drier California with more frequent and longer multi-year dry spells.

Some have already jumped to this conclusion.

This is the new normal,” Gov. Jerry Brown declared during an April 1 press conference announcing mandatory urban water restrictions statewide, the first in state history. The news media amplified the pithy quote and several other elected officials have repeated the claim as their own.

Brown made the announcement at a snowless Sierra snow survey site. The water content of the mountain snowpack, so crucial to California’s water supply, was only 5 percent of the April 1 average, by far the lowest reading on record for that date.

The governor’s phrase surfaced the following week during a conference on water scarcity organized by UC Davis graduate students. The students asked more than a dozen the speakers, “Is increased water scarcity in the West the ‘new normal’?”

The responses were diverse, suggesting a lack of consensus among water experts. Several speakers answered unequivocally in the affirmative.

“At the end of the day the answer is yes,” said Pat Mulroy, a senior fellow with the Brookings Institution and former general manager of the Southern Nevada Water Authority. “But I think what you’re (also) going to have is much more erratic precipitations. You’re going to have more rainfall, less snowfall. That change alone will make a huge difference and can contribute to the scarcity picture.”


Panelists at Water Scarcity in the West conference at UC Davis, April 2015.  Photo by Carole Hom/UC Davis

Other speakers – experts in atmospheric science, climatology, history, hydrology and water policy – hesitated to characterize increased water scarcity as a “new normal” without adding qualifiers to their response.

“Climate-wise, the norm depends on what time period you’re looking at…10-year, 30-year, 100-year or a 500-year [or a] 5000-year [period]?” said David Easterling, chief of the Global Applications Division at the National Climatic Data Center.

Paleoclimate records show California has endured “mega-droughts”  that lasted more than 100 years. Increased water scarcity, Easterling said, is “probably not” a new norm given the “huge swings” in the Earth’s climate over the eons.

Several studies report conflicting findings on the link between the California drought and climate change. But there is scientific consensus that increasing temperatures under climate change can worsen effects of drought, increasing evaporation and transpiration of surface water and soil moisture.

A warmer atmosphere will take more water from the land, said Reed Maxwell, a hydrology professor at the Colorado School of Mines. “That means the amount of water going into the terrestrial system, going into streams, going into groundwater, going to lakes… it has to be less.”

Other speakers pointed out that water scarcity is driven by both supply and demand.

While it remains to be seen how climate change will affect California’s water supply, water demand is certain to increase, said Richard Howitt, a UC Davis professor emeritus of agricultural and resource economics.

“With or without climate change, environmental requirements, our agricultural crop impacts and our population growth all contribute to increasing scarcity,” Howitt said. “We can cope with it, but we have to be smart about it.”

If anything clear emerged from the “new normal” discussion, it’s that the catch-phrase raises more questions than it answers. The interplay between climate change and water supply at local and regional scales is still poorly understood.

Proclaiming the current drought as the “new normal” under climate change is premature, if not deceptive. But it may help sell Californians on water conservation and prepare them for future droughts, which is likely what the governor and other politicians have in mind.

Stephen Maples, a graduate student in hydrology, helped organize the Water Scarcity in the West conference as a 2014-2015 fellow with the Climate Change, Water and Society IGERT (Integrative Graduate Education Research and Traineeship) program at UC Davis. IGERT Fellows Alejo Kraus-Polk and Lauren Foster contributed to this blog.

Further reading

Climate Change, Society and Water IGERT, UC Davis 

Cook E. et al. 2007. North American Drought: Reconstructions, Causes and Consequences. Earth-Sci. Rev. 81 (1) 93–134

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

Swain D. et al. 2014. The Extraordinary California Drought of 2013/2014: Character, Context and the Role of Climate Change [in “Explaining Extremes of 2013 from a Climate Perspective”]. Bull. Amer. Meteor. Soc., 95 (9), S3–S7

Wang H. and Schubert S. 2014. Causes of the Extreme Dry Conditions Over California During Early 2013 [in “Explaining Extremes of 2013 from a Climate Perspective”]. Bull. Amer. Meteor. Soc., 95 (9), S7–S11. PowerPoint version

Funk C. et al. 2014. Examining the Contribution of the Observed Global Warming Trend to the California Droughts of 2012/13 and 2013/14 [in “Explaining Extremes of 2013 from a Climate Perspective”]. Bull. Amer. Meteor. Soc., 95 (9), S11–S15

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California Drought: Virtual Water vs. Real Water

Source: Wikimedia Commons

Source: Wikimedia Commons

This article was originally published Feb. 27, 2014

By Jay Lund

There has been considerable kvetching during this drought about California exporting agricultural products overseas, with some saying that this implies we are virtually exporting water that we should be using in California.

Those concerned should take comfort with California’s major imports of virtual water. Much of the food consumed here comes from other states and countries, and their production, of course, requires water.

Much of the corn fed to California’s dairy cattle is grown on Midwest farms with Midwest water. And much of our clothing is made of imported cotton, a water-intensive crop, or made from petrochemicals, which used oil and water from elsewhere.

Tremendous amounts of water also is needed to grow Oregon’s forests that supply a lot of the lumber framing our new homes, to produce the steel in cars shipped to California and to run factories in China and Malaysia that make our computers and smart phones. Think of the virtual water all these other countries and states are exporting to us.

We live in a world of virtual flows of goods and services that produce the real goods and services we willingly buy in favor of less-efficiently made local goods and services. The economics of production are important – virtual water is not.

The virtual water notion can be applied to other production inputs. Consider California’s many virtual immigrants — people who did not need to move here because we import the products they make in other states and countries. Consider virtual energy use; some of the energy used to make your iPhone came from Iran via China, virtually avoiding trade sanctions with Iran.

“Virtual water” and related “water footprint” calculations are cute and popular. We can have lots of fun with the idea of a virtual this and that. (Virtual manure can be imagined coming and going from California and flowing globally.) These notions have some value for raising public consciousness on the roles and importance of water. But the wide range of water values and opportunity costs across the globe and over time commonly makes these calculations misleading.

Talk of virtual water distracts from serious discussion of economic, environmental and hydrological objectives and processes important for real water and environmental systems to function. Virtual water discussions are all the more counterproductive coming in the midst of a very real and serious drought.

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

Further reading

Frontier Economics (2008), The concept of ‘virtual water’ — a critical review, Report for the Victorian Department of Primary Industries, Australia.

Iyer, R.R. (2012), Virtual water: Some reservations, GWF Discussion Paper 1218, Global Water Forum, Canberra, Australia.

Merrett, Stephen W. (2003), ‘Virtual water’ and Occam’s razor, Occasional Paper No 62, SOAS Water Issues Study Group, School of Oriental and African Studies/King’s College London, University of London.

Neubert, Susanne (2008), “Strategic Virtual Water Trade – A Critical Analysis of the Debate,” in W. Scheumann et al. (eds.), Water Politics and Development Cooperation, 123 doi: 10.1007/978-3-540-6707-76, Springer-Verlag, Heidelberg 2008

Wichelns, Dennis (2010), Virtual Water and Water Footprints Offer Limited Insight Regarding Important Policy Questions, Water Resources Development, Vol. 26, No. 4, 639–651, December.

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Creeks that cool down as summer heats up

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Big Springs Creek near Mount Shasta (background) hosts an abundance of aquatic plants that lower water temperatures when salmon and trout need it most, during the dogs days of summer. Photo by Carson Jeffres/UC Davis

By Ann Willis and Andrew Nichols

Summer has just begun and conditions on many of California’s drought-stricken rivers and streams are already looking grim for cold-water fish.

Endangered winter-run salmon may not survive a repeat of last summer’s nearly total loss of eggs and fry from an over-heated Sacramento River. Low and warm flows in the Russian River watershed are threatening coho salmon and steelhead, prompting emergency water restrictions. And, last week, the state began evacuating rainbow and brown trout at the American River and Nimbus hatcheries to prevent die-offs over the summer.

However, not every California stream will turn perilous. In fact, some spring-fed streams are likely to become more hospitable during the dog days of summer.

Our on-going investigation of Big Springs Creek near Mount Shasta found that from May to August – when California streams generally warm up – maximum water temperatures cool by almost 3 degrees Fahrenheit. The cooling is all the more remarkable considering the creek is practically devoid of shade trees.

How could this be? The answer lies just below (and above) the water surface: aquatic plants.

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A young rainbow trout in Big Springs Creek. Photo by Carson Jeffres/UC Davis

Generally, the best way to maintain cold-water fish habitat is to keep cold water cool – because once water warms, it’s difficult to reverse the trend. In Big Springs Creek, plants known as macrophytes help to provide that benefit in the absence of shade trees. Just as streamside trees form a shady canopy over a creek, mature stands of these rooted vascular plants create a sun-blocking umbrella within the creek channel.

The plants typically grow in spring-fed streams with stable flows, open canopy and low gradient. Big Springs Creek nourishes an abundance of macrophytes because its waters are enriched with nitrogen and phosphorous from volcanic and sedimentary rock.  

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

Snowmelt from Mount Shasta runs underground through porous volcanic and sedimentary rock before eventually bubbling up in Big Springs Creek (center). Source: UC Davis Center for Watershed Sciences

In 2011, scientists with the UC Davis Center for Watershed Sciences and Watercourse Engineering Inc. had an opportunity to quantify just how much influence these plants have in regulating water velocities, depths and temperatures in Big Springs. The predominant shady macrophyte species in the creek are water peppercutleaf water parsnip and seep monkey flower.

Not surprisingly, our study found that plant growth improved the stream’s physical habitat by slowing the flow, which deepened the creek and better protected fish from predators. However, we did not expect the plants to have such a pronounced effect on seasonal water temperatures.

The plants start their seasonal growth in the spring when the creek is shallow and widely exposed to the elements. But as the plants grow and emerge above the creek surface, their influence on water depth and temperature increases. 

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Aquatic plants grow spring through summer. Early in the growth season, they have little influence on water temperature. But as they grow and emerge above the water surface, the plants deepen the creek and provide extensive shade, causing water temperatures to cool. Source: UC Davis Center for Watershed Sciences.

In May 2011, maximum water temperatures in the creek reached 68.5 degrees. By August, beds of these plants covered almost half the creek, water depths nearly doubled and 84 percent to 93 percent of solar radiation was blocked. Maximum water temperatures fell 3 degrees, to 65.5 degrees.

That’s right, summer temperatures in the creek cooled during the hottest time of the season. While maximum water temperatures have varied from year to year, the summer cooling pattern has held throughout the current drought.

The cooling effect of aquatic plant growth has important implications for restoration and management of certain spring-fed rivers and streams where these plants grow. For example, it’s easier to manipulate water temperatures by allowing these plants to flourish than by reshaping the stream channel or changing the flows from groundwater springs. Also, the plants’ rapid growth provides considerable short-term cooling compared with the time and cost of establishing canopies of shade trees.

The findings suggest that spring-fed streams have an important role to play as refuges for cold-water fish in a warming climate. Giving high priority to the stewardship of these streams will help sustain these important ecosystems in an uncertain future.

Ann Willis and Andrew Nichols are research scientists with the UC Davis Center for Watershed Sciences.

Further reading

Willis et al. 2012. Executive analysis of restoration actions in Big Springs Creek, March 2008-September 2011. Report prepared for National Fish and Wildlife Foundation

Willis et al. 2015. A salmon success story during the California drought. California Waterblog

Lusardi and Willis. 2014. Aquatic plants: unsung but prime salmon habitat. California Waterblog

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How to manage drought: Ask an economist

faceshots2.pngThe economics of water scarcity is crucial to sustainable water management, particularly during droughts. California has long benefited from the insights of economists, though their ranks in state water agencies are thinning. Luckily, California has a wealth of young, talented economists already active in public water policy and who will be around for future droughts. California WaterBlog asked five of them what California should be doing to prepare for a fifth year of drought and beyond.

Get inside consumers’ heads

By Kurt Schwabe

Does a lawn use more water than a pool? How much water will be saved by replacing turf with drought-resistant landscaping? Will it be cost-effective? What will be the effect on residential water use if a water agency incentivizes customers to use water more efficiently (adopts a budget-based tiered water rate)?

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Kurt Schwabe, UC Riverside

It depends. That is, these questions are difficult to unpack since they are intricately tied to human behavior.

For example, the degree to which drought tolerant landscaping saves a household water relative to turfgrass will depend on, among other factors, how they irrigated their lawn before and after replacement. Alternatively, the relative water use of a pool versus turfgrass also will depend on, among other factors, their irrigation habits prior to installing the pool. Unfortunately, restricting water use to fewer days a week – as some research shows – doesn’t necessarily save water, nor does refilling one’s pool every other day rather than every day (as one customer tried to convince me of during a recent trip to the barbershop). 

Historically, California’s management of severe drought has centered on engineering solutions. In the current drought, however, understanding human behavior and the demand side of water management is beginning to share the center stage.

Forward-looking water agencies are overcoming the stigma that investments in understanding human behavior are somehow less worthy than augmenting water supply in addressing drought. Indeed, these agencies are systematically evaluating numerous ways to improve demand-side management through analyses that identify:

  • Factors determining participation in conservation programs
  • Factors influencing residential water demand
  • Effectiveness of price and non-price conservation programs
  • Revenue and cost implications of alternative conservation options
  • Possible synergistic effects across conservation programs

Such efforts can lead to more informed, targeted and cost-effective conservation programs.

Kurt Schwabe is associate professor of environmental economics and policy at UC Riverside.

Increase role of water markets

By Katrina Jessoe

Economists have long recognized well-functioning water markets as a valuable tool for reducing the economic costs of drought.

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Katrina Jessoe, UC Davis

They involve voluntary transfers of water between parties, usually from higher priority to lower priority water-rights holders, at a negotiated price. They offer an opportunity to transfer water from lower value to higher value uses, regardless of whether those uses are for agricultural, urban or environmental purposes.

Water transfers in California have been occurring since the 1976-77 drought, but their role in managing droughts should be increased. Reducing transaction costs and expanding groundwater markets could do this.

The former does not imply that the environmental impacts of transfers should be ignored. Environmental costs are real and should be taken into account before approving a transfer. However, the current transfer process is cumbersome and drawn-out. A more streamlined approach could reduce transaction costs and encourage market activity.

The recently enacted Sustainable Groundwater Management Act, requiring local agencies to manage underground pumping and recharge sustainably, may encourage groundwater banking and borrowing.

Groundwater markets would allow for trading to occur over time with increased pumping during times of scarcity and the replenishment of aquifers during wet years. These transfers would introduce further flexibility in managing water resources.

 Water markets will not prevent droughts but they offer a feasible and flexible pathway to lessen their economic costs.

Katrina Jessoe is assistant professor of agricultural and resource economics at UC Davis.

Tiered water pricing works – and it’s legal

By Kenneth Baerenklau

What happens when there is a disruption in the supply of oil or some other commodity? The price tends to go up and demand tends to go down. The demand for water is no different.

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Kenneth Baerenklau, UC Riverside

There is an abundance of empirical evidence demonstrating that consumers reduce their demand for water in response to higher prices. In the residential sector, demand tends to fall by about 4 to 6 percent for every 10 percent increase in price (albeit with significant variability across circumstances).

But the difference between water and other commodities is that the prices charged by water agencies typically aren’t very responsive to disruptions in supply. That is, when water becomes increasingly scarce, prices don’t necessarily rise to reflect this scarcity, and thus demand doesn’t fall.

There are some good reasons for maintaining price stability related to the essential nature of water and the lack of good substitutes. But pricing nonetheless remains a very effective tool for managing water demand.

A recent court decision in an Orange County case may have left the impression that a particularly popular and effective “tiered” approach to water pricing is unconstitutional in California.

On the contrary, the court stated clearly that tiered pricing is not unconstitutional and furthermore makes good sense. Debate remains over the types of costs that can be passed on to customers as higher water prices. Californians nevertheless should expect their water suppliers to rely more heavily on pricing to achieve conservation goals as this drought continues, and even more so when the next one comes around.

Kenneth Baerenklau is associate professor of environmental economics and policy at the UC Riverside School of Public Policy

Keep closer tabs on crop water use

By Josué Medellín-Azuara

Agriculture in California, as in many other parts the world, has the lion’s share of water use. The industry uses 80 percent of the water consumed in the state in a normal year. Yet the state’s method of tracking all that water use has not kept pace with the needs of modern water management.


Josué Medellín-Azuara, UC Davis

Estimating farm water use requires data on cropping patterns, land use, water deliveries and irrigation methods. At best, this information is available annually. It takes county agricultural commissioners and state agencies that long to collect it.

Effective water management calls for timelier water-use accounting, especially during droughts.

Modern measuring methods using multispectral satellite imagery make it possible to estimate farmers’ “consumptive” water use — the amounts of irrigation water crops transpire and evaporate from the nearby soil.

Consumptive water-use estimation using satellites in combination with ground-level weather data and land-use surveys can greatly improve the timing, accuracy and effectiveness of this information.

Other western states use this remotely sensed measurement technology to quantify consumptive use and manage their water rights system. The technology is relatively inexpensive (just cents per acre in Idaho).

A consortium of federal and state agencies can make this endeavor possible. A concerted effort to organize, document and distribute this wealth of information is needed.

Josué Medellín-Azuara is a senior researcher specialized in hydro-economic modeling at the UC Davis Center for Watershed Sciences

Monitor and manage our groundwater

By Duncan MacEwan

The ability of California growers to offset shortfalls in surface waters supplies with increased groundwater pumping is critical to avoid costly crop losses during droughts. Growers pumped an additional 5.1 million acre-feet (maf) of groundwater in 2014, offsetting 75 percent of the surface water shortage that drought year.

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Duncan MacEwan, ERA Economics

But mining groundwater this way carries costs that undercut agricultural productivity in the long run.

Pumping groundwater water faster than nature replenishes it results in depletion of the groundwater in a basin. In the last decade, California’s Central Valley overdrafted its groundwater reserves by more than 20 maf. Average annual overdraft ranged from 0.4 maf in average water year conditions to more than 1.4 maf in dry years [1].

The standard cost of groundwater overdraft is the additional energy required to pump from a lower water level. But there are two additional, and perhaps more important, economic costs: the buffer value and stranded capital costs.

The buffer value is the value of having groundwater stored and available for use during drought years. It is reflected in the ability to irrigate higher-value crops in dry years by planting fewer acres of lower-value crops in wet years. The stranded capital cost is the present value of the remaining useful life of assets such as wells and orchards that were lost during drought as a result of insufficient groundwater.

California’s Sustainable Groundwater Management Act of 2014 paves the way for conjunctive rather than extractive groundwater management. That is, groundwater pumping may exceed the natural rate of recharge during dry years, but must be replenished in wet years to avoid additional economic costs.

The current drought has highlighted the value of our groundwater reserves to agriculture. We have learned that we must monitor and manage our groundwater to preserve the marginal pumping cost, buffer value and stranded capital costs. The new groundwater laws move us in that direction.

[1] Author’s calculations using DWR’s C2VSim model data.

Duncan MacEwan is managing partner at ERA Economics in Davis, Calif., specializing in water resources and agriculture.

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