Roaches of California: Hidden Biodiversity in a Native Minnow

by Peter B. Moyle



If you inspect small streams in northern California, including those that seem too small or warm for any fish, you will often see minnows swimming in the clear water. Chances are you are seeing a very distinctive native Californian, usually called California roach.  This fish is a complex of species that occurs as far north as Oregon tributaries to Goose Lake and is widespread in tributaries to the Sacramento and San Joaquin rivers, as well as in rivers along the coast from the Eel River to Monterey.

“California Roach” is the name originally given to some minnows collected in 1854 from the San Joaquin River.  When the great Stanford ichthyologists David Starr Jordan and Barton Warren Evermann put these fish into their grand monograph Fishes of North and Middle America, they decided it looked like the roach (Rutilus rutilus), a common minnow in England and Europe.  They then gave it the scientific name Rutilus symmetricus.  While the relationship to European roach was dismissed by John O. Snyder in 1913, the unfortunate common name of “roach” stuck.  Snyder placed California Roach in its own genus, Hesperoleucus, and divided it into six species, based on body shape and counts of fin rays and scales (see Table).  His species were also based on the isolation of their home waters from other watersheds, which would prevent interbreeding.

Because roaches are small inconspicuous fishes, little formal attention was paid to their taxonomy (or status).  By the 1950s, there seemed to be a general consensus that Snyder’s species were at best subspecies and the California roach was back to one species.  This was reflected in the classification presented in my 2002 book, Inland Fishes of California, although the species was divided into eight subspecies.   Then, Andres Aquilar and Joe Jones (2009) looked at populations that were part of this ‘species complex’ using mitochondrial and nuclear DNA. Their analysis indicated that two of Snyder’s species, northern roach and Gualala roach, were strongly supported as ‘good’ species.  The other six subspecies I listed in 2002 were at least supported as distinct genetic units by their analysis.

To clarify the relationships among the species more firmly, new techniques in genomics were brought to play.  This effort was led by Jason Baumsteiger, a postdoctoral scholar at the Center for Watershed Sciences and in the genomics laboratory of Mike Miller.  He performed restriction-site associated DNA (RAD) sequencing on roach samples collected throughout California to discover and genotype thousands of single nucleotide polymorphism (SNPs) (see Baumsteiger et al.  2017). This detailed examination of the genomes of roaches from throughout their range allowed determination of how much each population had diverged from other populations.  Among other things, it allowed for ‘rules’ to determine which populations were species, subspecies, or distinct population segments.

Distinct population segment (DPS) designations are based on the use of DPS designations under the national Endangered Species Act; they are isolated populations that are distinctive, but not quite different enough so to be called species or subspecies. DPS designations are widely used for determining whether or not salmon and steelhead populations are eligible for protection under the ESA.

The application of genomics to the taxonomic relationships of roach populations (Baumsteiger and Moyle 2019) resulted in our recognition of five species, four subspecies, and 5 distinct population segments (Table 1). The five species each have distinctive, interesting features.

The California roach is the most widespread species, historically found in streams throughout the Central Valley, with many opportunities for adaptation to local conditions, such as those found in the Kaweah River (hence the Kaweah roach DPS). It appears to be losing these locally-adapted populations rapidly, however, as they become increasingly isolated by dams and damage to streams, and by invasions of their small stream refuges by green sunfish and other non-native predators.

The Clear Lake roach is a bit of mystery because it a perfect hybrid between coastal roach and California roach.  This fits the geologic history of the region, which has been alternately connected to the Russian River and to the Sacramento River. Presumably representatives from both watersheds made it into the Clear Lake basin at times and hybridized.  The hybrid was apparently superior to either parent species in its ability to persist in streams tributary to Clear Lake.  Today, the Clear Lake roach is more isolated than ever, because the lake is full of non-native predatory fishes.

Hybridization also has led to the development of new species in the northern roach.  This roach inhabits small streams and springs of the upper Pit River basin and looks like other roach species.  So we were surprised when the genomics study showed that about 80% of the genome was like that of the hitch, a related species in a different genus (Lavinia exilicauda).  This seems to have been from an ancient hybridization, perhaps when Sacramento Valley fishes invaded the Pit River region thousands of years ago. Curiously, we also found that the roach-like fish abundant in Hetch-Hetchy Reservoir, on the upper Tuolumne River, also are hitch-roach hybrids even though they were introduced into the reservoir by persons unknown.

The southern coastal roach is also known to hybridize with hitch, where the two species occur together naturally, but these hybrids seem unimportant to the populations of both species. The presence of subspecies and DPSs in the coastal roach distribution reflects the isolation of coastal watersheds from one another with enough connections in the past to keep populations from differentiating enough to be labeled species.  This also makes the Gualala roach a bit of an anomaly, given that watersheds on both sides of the Gualala River contain coastal roach.   The northern coastal roach also shows how rapidly a species can spread when introduced into new watershed, in this case the Eel River. These roach, probably introduced in the 1960s, now occupy most of the accessible habitat in the Eel, one of California’s largest watersheds; the genomic study indicates that they came from fish in the Russian River roach DPS, just to the south, so were pre-adapted for conditions in the Eel River.

This study of small fishes demonstrates again the high endemism in fishes that are adapted to the special, often harsh, conditions in California streams.  This surprising diversity is another example of what makes California special and needing of a well-supported, state-wide conservation strategy. The roach species complex is also good example of hidden biodiversity revealed by new genetic techniques.  Modern genomics can support conventional taxonomic methods to designate species, subspecies, and DPSs and should improve our ability to conserve California’s richness of fishes.


Northern roach. Photo by Stewart Reid


Common name Scientific name Snyder 1913 Moyle 2002 Notes
California Roach H. symmetricus H. symmetricus H. symmetricus Name applied to all roach by Moyle 2002 and others
Red Hills Roach H. s. serpentinus H. s. subsp. Serpentine endemic; Tuolumne County
Central California Roach H. s. symmetricus H. symmetricus H. s. symmetricus Tributaries to Central Valley
Kaweah  Roach H. s. symmetricus H. s. symmetricus DPS, Kaweah River
Clear Lake Roach H. symmetricus x venustus H. s. subsp. Hybrid that behaves like a full species; tribs. to Clear Lake
Coastal Roach H. venustus Originally multiple species/subspecies
Northern Coastal  Roach H. venustus navarroensis Introduced into Eel River.
Russian River Roach H. venustus navarroensis Lumped with Clear Lake Roach DPS, introduced into Eel River
Navarro Roach H. venustus navarroensis H. navarroensis H. s. navarroensis DPS, Navarro R.
Southern Coastal Roach H. venustus subditus
Tomales Roach H. venustus subditus H. s. subsp. DPS, Tomales Bay streams
Monterey Roach H. venustus subditus H. subditus H. s. subditus DPS, Salinas-Pajaro watersheds
Northern Roach H. mitrulus H. mitrulus H. s. mitrulus Pit River; originated as hybrid with Hitch.
Gualala Roach H. parvipinnis H. parvipinnis H. s.  parvipinnis Gualala River

Further readings

Baumsteiger, J. and P. B. Moyle. 2019. A reappraisal of the California Roach/Hitch (Cypriniformes, Cyprinidae, Hesperoleucus/Lavinia) species complex. Zootaxa 4543 (2): 2221-240.  (available as open-access download)

Baumsteiger, J., P. B. Moyle, A. Aguilar, S. M. O’Rourke, and M. R. Miller. 2017. Genomics clarifies taxonomic boundaries in a difficult species complex. PLoS ONE 12(12): e0189417. (available as open access download)

Moyle, P.B. 2002. Inland Fishes of California.  University of California Press, Berkeley.

Peter B. Moyle is a UC Davis Professor Emeritus of fish biology and an associate director of the Center for Watershed Sciences.


Classic California roach habitat.  Dye Creek, Tehama County, July 2014

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15 Years of the San Francisco Estuary and Watershed Sciences – Open Access Journal

By Lisa Howardpjh_delta_farming-0250_700x400.jpg-copy

originally published January 21, 2019

When the peer-reviewed journal San Francisco Estuary and Watershed Science launched fifteen years ago, the editors chose what was then a somewhat new model of scientific publication known as “open access.”

At that time, most academic journal publishers kept their content behind pay walls, accessible only with expensive subscriptions that were mostly paid by institutions like universities.

The sequestered academic content was a big problem when it came to research about the San Francisco Bay-Delta watershed, which includes not only the San Francisco Bay, but all the waters that feed into it — a combined area of more than 75,000 square miles.

The Bay-Delta watershed provides critical habitat for plants and animals, drinking water for more than 25 million Californians, irrigation for thousands of square miles of agriculture, as well as recreation facilities and a transportation route for deep-water shipping.

“Universities had access to the scientific journals, but the agencies and stakeholders involved in managing California’s water didn’t,” said Samuel Luoma, a research ecologist with the John Muir Institute of the Environment (Muir Institute) at UC Davis and editor-in-chief of SFEWS.

In 2000, Luoma was the lead scientist for the CALFED Bay-Delta Program. He headed a committee that was looking for ways to improve collaboration and access to research about water and watershed issues in Northern California. The committee consisted of representatives from federal and state agencies, water users and universities.

“The idea that came out of the committee was to create a peer-reviewed publication that was authoritative and objective, and that everyone interested in California water could read, and could write for, at no cost,” said Luoma.

To help turn the idea into reality, Luoma teamed up with James Quinn at UC Davis, Randy Brown and Lauren Muscatine at the California Department of Water Resources, and Fred Nichols at the U.S. Geological Survey. Brown and Nichols would go on to become the first co-editors and Muscatine would become the managing editor.

A common model of open-source publishing is to have authors pay to have their works published. To make sure their new journal would be free to both read and write for, they secured funding from the State of California, through what is now the Delta Stewardship Council’s Delta Science Program.

A partnership with the Muir Institute, which generates policy-relevant research to solve environment challenges, established a home for the journal at UC Davis. And with the California Digital Library’s eScholarship Publishing Group, they had a publishing platform.

SFEWS launched in October 2003, the same month another open-access journal made its debut, Public Library of Science or PLOS.


Samuel Luoma, editor-in-chief, and Lauren Muscatine, managing editor, along the Embarcadero in San Francisco. (Lisa Howard/UC Davis)

The science of California’s complex and contentious water issues

The first issues of SFEWS featured topics familiar to anyone who follows California water: tidal wetlands restoration; sediment; mercury in the food chain; and the impact of wetland restoration on native fishes like chinook salmon, steelhead rainbow trout and Delta smelt.

Later issues featured research on groundwater, drought, atmospheric rivers, Traditional Ecological Knowledge for restoration, floodplain management, zooplankton distribution, climate change, and ecosystems along the Sacramento River, just to name a few. Early papers on Delta smelt, climate change, and threats to the Delta remain among the most cited. A recent piece tackled the misperception that river water flowing through the Delta to San Francisco Bay and on to the Pacific Ocean is “wasted.”

“Some of the biggest battles over California water — whether farmers get the water or the environment gets the water or the cities get the water — is because we don’t have enough water,” said Luoma. “And the biggest battles are centered around scientific issues. How much water can we divert for agriculture and the cities? How much for our endangered species?”

To answer those questions, policymakers and agency scientists rely on research published in SFEWS.

“The rules about when you can divert water, and when you can’t, are structured around what we know about Delta smelt and salmon,” said Luoma. “Fundamental reviews and papers about Delta smelt and salmon have been — and will continue to be — published in the journal. The journal has had a lot of influence on many of the policies that were created and continue to be disputed and re-created.”

“Our journal’s regional focus offers authors a chance to publish research that may uncover novel solutions to help solve some of the most significant problems that California policymakers are addressing today,” said Muscatine. “Some of these solutions, if proven successful, may be applicable to similar ecological systems around the world.”

Making UC research available to a wider audience

Fifteen years on, the impact of open-access publishing has also matured. When SFEWS launched, there were about 1,800 open-access journals. Now there are more than 12,000. PLOS ONE has gone on to become the largest multidisciplinary peer-reviewed journal in the world.

Although the research in SFEWS is focused on a specific niche — the San Francisco Estuary and its watershed — the impact of the science is massive.

Since the journal’s launch in 2003, a total of 49 issues have been published, averaging 20 to 25 papers per year, and resulting in a total of 266,372 requests for access to articles. It continues to be jointly published by the Muir Institute and the Delta Stewardship Council.

SFEWS authors are continuing to tackle California’s water management and environmental issues from all sides. Their efforts represent studies from over 110 academic disciplines and 350 institutions,” said Muscatine.

Articles from the journal have been picked up by news outlets like Mother Jones, Wired, and Stanford News, making high-quality, policy-focused research widely discoverable beyond the open-access environment.

“The mission and vision of San Francisco Estuary and Watershed Science has been forward-looking from the beginning,” said Ben Houlton, director of the Muir Institute. “The research addresses California’s complex water issues in a completely non-partisan way, which is why it has been such a tremendous asset over the past fifteen years. And with the uncertainty about how climate change will affect California’s watersheds, it will continue to be a valuable asset for years to come,” said Houlton.


More Reading!

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Droughts and progress – Lessons from California’s 2012-2016 Drought

By Jay Lund, Josue Medellin, John Durand, and Kathleen Stone


Lake Cachuma in Southern California, February 2017

Droughts and floods have always tested water management, driven water systems improvements, and helped water organizations and users maintain focus and discipline.  California’s 2012-2016 drought and the very wet 2017 water year were such tests.  Historically, major droughts accelerate innovation and are career tests for agency and political leaders.  We recently summarized major lessons from California’s 2012-2016 drought (Lund et al. 2018). (Wet year failures from 2017 brought additional lessons.)

California accommodated the most recent droughts and floods fairly well – with some important exceptions.  It is worthwhile to show how such a large drought could have such small impacts on most Californians, and to draw lessons for how all sectors might reduce drought impacts in the next inevitable drought.  Contrasts for four sectors are particularly poignant.  Future droughts and floods are expected to be greater and perhaps more frequent, so recent relative success should not encourage complacency.

Managed well and poorly

California’s large urban systems fared well in the drought.  This contrasted with previous major droughts in 1976-77 and 1988-92, when major water systems were forced into mandatory water conservation.  Santa Cruz and Santa Barbara (with relatively isolated water supply systems) were the only major cities which imposed mandatory use reductions due to local water supply shortages, for one year each of the 5-year drought.  Despite sizable population growth since previous droughts, major urban areas were well prepared for this drought due to increasing water conservation (substantially driven by more conserving plumbing standards) and major improvements in infrastructure and regional cooperation (expanded groundwater and surface storage, wastewater reuse in southern California, drought plans, and water trades and markets) since previous major droughts.  In 2015, mandatory statewide reduction in urban water use by 25%, to prepare for a longer drought, led to negligible regional economic impacts because it was accommodated mostly by reducing urban landscape irrigation (normally about 50% of statewide annual urban water use).

Most agricultural areas largely continued to prosper during the drought, thanks largely


Fallowed field in southern Central Valley, 2015

to groundwater access, good national and global commodity prices, and flexible operations and water trades.  However, agricultural production and management was challenged widely and some farming areas found themselves unprepared and suffered considerable losses.  Again, preparation was key to minimizing losses.  The prominent importance of groundwater led to state regulation of groundwater in 2014 to help ensure adequate sustainable groundwater supplies for more profitable perennial crops, which are more expensive to fallow in dry years.

Rural drinking water supplies faced sometimes severe challenges, largely due to additional agricultural pumping from deeper, larger-capacity wells.  These small systems, which are more vulnerable under many conditions, remain one of California’s most challenging, but more solvable water problems.  A modest amount of regular funding, well organized and applied, along with better sustained groundwater levels, would address the worst of this problem for future droughts.

Ecosystems saw the greatest drought impacts, which are still being felt in terms of recent wildfires.  Perhaps the biggest effects of the drought are for forests and wildfires statewide.  Several recent large wildfires, made worse by the drought and climate warming, have been locally devastating and had a statewide economic impact many times that of the major 5-year drought.  Aquatic ecosystems in much of the state, already weakened by longstanding multiple stressors and unrecovered from previous droughts, were also harmed.  Environmental flows were sometimes reduced in favor of economic activities.  Waterfowl were less harmed in the drought due to effective cooperation among private, NGO, state, and federal refuge managers to adaptively manage and supply wetlands for migratory birds, an example of effective drought management for an ecosystem.  Again, for all these sectors, reductions of future drought impacts will require organization and investment in preparation well beyond that done before the drought.

Lessons from California’s 2012-2016 drought

  1. Drought tests improve management in well-run water systems. Each drought in California’s history has led to improvements in water management, often responding to long-term problems and opportunities. The recent drought highlighted the dependence of California’s agriculture on groundwater in dry periods, and brought substantial legislation for more effective local groundwater management. Incremental improvements in water accounting, urban water conservation, and other areas were accelerated by the drought. Diligent reflection and discussion from the recent drought should lead to further improvements, particularly for the less prepared, less organized areas of managing ecosystems, rural water supplies, and environmental and water right regulations. The reports for the Oroville spillway failures in 2017 and the 1976-77 drought are superb examples.
  2. California’s diverse economic structure and deep global connections greatly reduce drought’s economic impacts. California and other modern global economies depend less on abundant water supplies than in the past. High values for California’s major export crops greatly reduced the impacts of fallowing to about 6% of the least-profitable irrigated land during the drought. Despite important local problems, the drought had little effect on California’s statewide economy. Urban areas, supporting most people and economic activity, had already developed diversified water supply and conservation portfolios successfully from previous droughts, with some additional improvements.
  3. Globally, California is more robust to drought and climate change from its organized water systems, irrigated agriculture with diversified supplies, substantial groundwater, and adaptability with water networks and markets. California’s extensive diverse water infrastructure allowed more than 70% of water supplies lost to drought to be replaced by pumped groundwater for agriculture and shifting of surface water supplies, requiring greater groundwater recharge in the long term. California’s irrigation infrastructure and network of reservoirs and canals mute drought effects, and are particularly effective for protecting the most valuable crops and economic activities. With long-term reductions in the least-profitable irrigated area, this system can be sustainable.
  4. Ecosystems were the sector most affected by the drought, given the weak condition of many native species after decades of losses of habitat and water and the growing abundance of invasive species. Forests are particularly vulnerable and difficult to protect from droughts. With each drought, humans become better at weathering drought, but effective institutions and funding are lacking to improve ecosystem management and preparation for drought. Dedicated environmental water rights and restoration and migration programs can help support ecosystems. Such actions are needed to break the cycle accumulating drought impacts to ecosystems.
  5. Small rural water systems are especially vulnerable to drought. Small systems often struggle in normal years, lack economies of scale, typically have only a single vulnerable water source, and commonly lack sufficient organization and finance. Accumulating overdraft, accelerated during drought, brings a growing number of dry domestic and community wells in rural areas.
  6. Every drought is different, and motivates further improvements. Each drought is hydrologically unique and occurs under different historical, economic, ecosystem, and climate conditions. But all droughts provide opportunities and incentives to improve water management for changing conditions and priorities. In well-managed systems, each drought is greeted with improved preparations from previous droughts.

Major water agencies should reflect on and document lessons from the last drought to help prepare for the future droughts.  Such documents are important for policy discussions and as background for water managers and policy-makers entering a new drought.  Periodic regional drought “dry run” exercises also would help prepare agencies for droughts, and particularly help agencies to work well together during drought (and at other times) – much like annual flood and earthquake exercises.

Every generation needs at least one threatening drought to motivate water system improvements and collaborations among the many agencies and interests involved in water management and use.  Droughts are unavoidable, but their effects are much less if we organize, prepare, and respond appropriately.

Further reading

Department of Water Resources (DWR) (1978), The 1976-1977 California Drought – A Review, California Department of Water Resources, Sacramento, CA, 239 pp.

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

Independent Forensic Team, Independent Forensic Team Report – Oroville Dam Spillway Incident, 5 January 2018.

Lund, J.R., J. Medellin-Azuara, J. Durand, and K. Stone, “Lessons from California’s 2012-2016 Drought,” Journal of Water Resources Planning and Management, October 2018. (open access)

Medellín-Azuara, J., D. MacEwan, R.E. Howitt, G. Koruakos, E.C. Dogrul, C.F. Brush, T.N. Kadir, T. Harter, F. Melton, J.R. Lund,” Hydro-economic analysis of groundwater pumping for California’s Central Valley irrigated agriculture,” Hydrogeology Journal, Vol. 23, Issue 6, pp 1205-1216, 2015.

Jay Lund is the Director of the UC Davis Center for Watershed Sciences. Josue Medellin is an acting Associate Professor of Engineering at UC Merced.  John Durand is a professional researcher and Kathleen Stone is a graduate student at the UC Davis Center for Watershed Sciences.


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Improving public perception of water reuse

test-the-process-with-logosBy Kahui Lim and Hannah Safford

Water reuse is becoming more important to water security in arid regions like California. The California Recycled Water Policy calls for an increase of 1 million acre-feet of reused water per year by 2020 and 2 million by 2030.  Assembly Bill (AB) 574 mandates that California establish a legislative framework for direct potable reuse (DPR)—where highly treated wastewater is recycled for drinking and other potable purposes—by 2023.

Technology already exists to treat reused water to levels meeting or exceeding health standards. But adequate technical capacity is not sufficient. Water reuse can trigger revulsion, especially when water is reused for drinking or other potable purposes. This note explores outreach and engagement strategies to overcome the “yuck factor” and achieve public support for water reuse.

Case studies

Los Angeles East Valley Water Recycling Project

In 1995, the Los Angeles Department of Water and Power (LADWP) began developing the East Valley Water Recycling Project. This $55 million water-reclamation project was intended to help “drought-proof” Los Angeles by using treated wastewater for groundwater recharge, irrigation, and other purposes. The project secured necessary approvals and construction was completed in 2000.

But as East Valley was about to come on-line, it was derailed by a public-relations disaster. Problems began when the Los Angeles Daily News published an article about East Valley with the headline “Tapping Toilet Water.” The concept of sewage being used for drinking sparked public outcry.

At the same time, an open Los Angeles mayoral contest was beginning. Several candidates seized on opposition to East Valley as campaign fodder, pledging to put a stop to “toilet-to-tap.” City attorney James Hahn was ultimately elected and made good on this promise. Hahn shut down East Valley and required LADWP to sever the pipeline bringing recycled water to the Hansen Spreading Grounds.

That public outcry could undermine a finished, $55 million project illustrates the importance of robust public engagement. As Gerald Silver, President of the Homeowners of Encino, said of LADWP’s poor outreach around East Valley: “Reaching out means reaching out in a way that people will understand.”


The severed pipeline at the Hansen Spreading Grounds is a reminder of public power and the importance of outreach.

Water reuse in Orange County

The Orange County Water District (OCWD) provides a successful example of water reuse. In 2008, OCWD began operating the Groundwater Replenishment System (GWRS), treating treated more than 70 million gallons per day of wastewater to potable standards. The product was then sent to replenish local aquifers used for drinking water.

The project has been widely recognized for its emphasis on education and engagement as well as engineering. A full decade before beginning construction, OCWD launched a public relations campaign to overcome negative perceptions of water reuse and secure broad support. The campaign employed various outreach strategies, including facility tours, television ads, briefings for elected officials, and partnerships with community groups and community leaders. It worked; the GWRS faced no substantial opposition.  Media coverage of the project was generally positive, including headlines like “How California is Learning to Love Drinking Recycled Water” and “Magic in a Bottle”.

OCWD continues to creatively prioritize public relations as the GWRS expands. In 2017, OCWD secured special permission to bottle its recycled water for consumption. The bottles were distributed at tasting events throughout Southern California. In 2018, OCWD gained substantial media attention by earning a Guinness World Record for the most recycled water produced in 24 hours.

 Research insights

Research confirms that outreach and engagement can increase acceptance of water reuse. Providing consumers with information on water reuse is a good first step. A survey commissioned by the water-technology company Xylem Inc. found that 89% of California residents are more accepting of reused water after learning more about the treatment process. A similar survey from the Victor Valley region of Southern California found that educating respondents about water reuse increased support for water reuse projects by 8 percent and decreased opposition by 7 percent.

Research also suggests ways to tailor messaging around water reuse. Public reaction to water reuse is often influenced by “affect heuristic,” a psychological principle that refers to people’s tendency to instinctively react to a stimulus based on prior experiences with similar or related things. Affect heuristic makes it difficult for people to overcome disgust associated with wastewater and accept scientific evidence that water reuse is safe. Numerous strategies exist to combat this heuristic. The Xylem survey found that referring to reused water as “purified” water garners stronger support for its use as an additional local water supply than referring to it as “recycled” or “reclaimed” water. Other studies have found that emphasizing the low risks of water reuse increases support more than emphasizing the benefits. Finally, messaging should avoid terms with negative connotations (such as “sewage” or “waste”) and incorporate terms with positive connotations (such as “clean” and “sustainable”).

In addition, it is helpful to provide opportunities for people to experience water reuse firsthand. Pure Water San Diego and the Silicon Valley Advanced Water Purification Center are just two of the multiple water recycling projects that, like OCWD, offer regular public tours. Tours allow participants to sample finished water: a powerful strategy for increasing consumer acceptance. As Marta Lugo, a public information representative of the Santa Clara Valley Water District (SCVWD, which oversees the Silicon Valley project), noted: “If people see their neighbors taking a taste, or their friends and peers, they get over a psychological barrier—it becomes normalized.” Indeed, the SCVWD found that taking a tour more than doubled the percentage of people strongly in favor of potable wastewater reuse.

Key takeaways

1: Engage proactively

The LADWP case study shows that it is difficult to recover once a negative narrative has taken hold. Hence outreach should begin early, during project planning. Options include working with community organizations, the media, and local leaders to explain how and why key decisions were made; sending brochures to utility customers; and hosting informational booths at public events.

2: Message carefully

How information is delivered is as important as the content itself. Messages should be delivered in clear, non-technical language, and should emphasize positive aspects and low risks of recycled water. It is also useful to articulate how water recycling can mitigate local water-supply issues.

3: Encourage public involvement

Broad public involvement in creates a sense of ownership that increases support. Project managers should consider recruiting local and stakeholders for advisory councils, providing opportunities for public comment, and offering tours and open houses.


Kahui Lim ( and Hannah Safford ( are graduate students of environmental engineering at UC Davis. This blog was prepared for the course “ECI 289: Synergies Between Environmental Engineering and Water Policy” and originally published as a policy brief through the UC Davis Policy Institute for Energy, Environment, and the Economy. [Click here to download this blog as a PDF]

 Further reading






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Shared interest in universal safe drinking water

by Jay Lunddbk_pouring_water-001

Public health is every society’s and every drinking water system’s most fundamental objective.  The prosperity and existence of civilizations rest on drinking water being safe, available and affordable.

Prosperity and democracy together seem almost essential to having near-universal safe drinking water supplies.  Prosperity and democracy together bring effective social organization and resources needed to deliver safe and affordable drinking water. See Table 1.

Table 1. Countries with Near-Universal Safe Drinking Water

safewatercountriesTable notes: Safe drinking water from Prosperity here means average GDP per capita > $30,000/year Freedom from

California’s failure to provide safe, affordable drinking water to the remaining roughly 1% of residents is probably the most solvable and affordable of California’s many difficult water problems.  There will always be isolated small systems with vexing problems, but the number of Californians currently without access to safe affordable drinking water is embarrassing and irresponsibly high.

California’s entire water industry and the public share an interest in nearly ubiquitous availability of safe drinking water.  The water industry, as professionals, have a special leadership interest in maintaining high public expectations for nearly ubiquitous drinking water safety and supplies.  Such universally high expectations are fundamental to the industry’s professional reputation and success, as well as public faith that water systems are well-managed by elected and appointed leaders and the professions.

Much like rural electrification and phone service, most of California’s safe drinking water problem comes from the small size of rural water systems, which compounds their costs and organizational difficulties.  California and the US have addressed other rural problems with additional general fees on electricity, phone, and postal service to provide basic service for rural residents.

Rural postal service is much more expensive than urban and suburban service, but is not charged more for deliveries.  California’s Public Utilities Commission currently collects surcharges totaling 5.5% on customers by telecommunications carriers for various federal and state subsidies for the poor and disabled to access telecommunications and for 911 emergency services.  CPUC also has rate surcharges on energy bills to fund programs for low-income customers (CARE program).  These are things we pay for to help maintain civilization.

In recent years, public health and rural interests have developed and promoted proposals (SB 623 in 2017 and SB 844 and SB 845 in 2018) for fees to help support rural drinking water systems.  Some proposed fees have been on agriculture to somewhat compensate for fertilizer and manure impacts to rural drinking water.  Other fees are proposed on public drinking water system users, much like telephone and energy customer fees to support low-income and emergency connectivity. Governor Newsom recently endorsed such a fee.

Public health and rural community advocates strongly advocate for these proposals.  California’s agriculture has largely supported these fees, which would be both modest and help avoid some state enforcement of regulations on nitrate contamination.  However, most urban water agencies have opposed new additional fees, even though the 2018 proposals made some urban fees voluntary, allowing customers to opt out.

California’s urban water agencies publicly voiced two objections: a) having public water systems collect the fee was too administratively difficult (especially for small systems) and b) support for rural drinking water system safety should be from State general taxes, not water industry fees.

The first objection can be easily addressed by modifying urban fee proposals to exempt very small water systems (who tend to have high costs and few customers anyway) and delaying this requirement by 2-3 years so fee collection is included in the next utility billing software upgrade, minimizing burdens to utilities and customers.  (A task force of local utilities and the state might lay out common standards for software implementation.)

The second objection is more fundamental, but understates the social compact between public utilities and the society.  Some individual public water utilities see their social responsibilities as only local, and not necessarily industry-wide, yet they rely on broader public support and industry standards.  Customer fees for telecommunication and energy use have long supported poorer and more rural customers – and doing so has made these industries and the public stronger.  California’s urban water industry would see long-term benefits in public perception and trust from showing leadership in providing safe drinking water statewide, rather than only in their local service areas.

A third often unstated urban water agency objection is that one small fee on urban water users would establish precedence for additional larger fees on urban water users for other underfunded water problems (stormwater, flood control, ecosystem management, statewide infrastructure subsidies, etc.).  This is a reasonable objection.  Urban water users, facing growing costs for local infrastructure renewal, cannot have primary responsibility for funding solutions to all water problems.

To reduce this problem, a new proposal might include a “brake” on expanding urban water fees.  Such a brake might have the state general fund be required to match funds raised from utility fees.  (After all, the legislature now has $430 million/year fewer bond repayment obligations following failure of Proposition 3.)  Such joint funding would encourage steady funding by both water utilities and the legislature.  Expanding water fees under such a shared arrangement would bring legislative resistance to expanding general fund contributions.  During recessions, legislative reductions in the general fund share would encounter rural and water utility resistance.

A limitation of recent proposals has been focus on supporting rural safe drinking water access.  This is the most pressing problem, but another equity problem has been difficulties for drinking water agencies to support “lifeline” water rates for poorer customers under Proposition 218 requirements that customer water rates be proportional to services to the customer property, making it difficult for public agencies to subsidize lifeline rates with higher general water rates.  Having the state require a fee (even a opt-out fee) to support local lifeline rates would help address both urban and rural access to affordable safe drinking water.  Funding a more general lifeline rate program would require considerably more money, but would improve safe affordable drinking water access for both local water utilities and statewide. (The SWRCB is exploring a very extensive water rate assistance program.)

A final problem with funding safe affordable drinking water is the sometimes big difference between raising funds and making sure funds are effectively employed.  An annual or biannual review of the state of safe drinking water availability accompanied by an external independent financial and effectiveness audit of funds would be important for maintaining subscriptions to voluntary fees as well as legislative support, and ensuring that solutions are effective.  Programs and people tend to resist real accountability (every tenured professor knows this), so some arms-length, meaningful, and transparent accountability is needed.  Some technical and financial support also is needed for county governments, which often must oversee struggling rural systems.

Local water utilities and the broad water industry benefit from broad commitment to supporting safe drinking water systems statewide.  There are dangers to all water utilities from not supporting public water systems generally.

A modest proposal

A modified funding proposal to help address previous concerns might roughly include:

  • $50 million/year from fertilizer and dairy manure charges (based on previously-proposed legislation, but at a little higher rate more commensurate with likely future drinking water costs from nitrate contamination)
  • $0.3/month mandatory fee for all public drinking water system customers, raises ~$30 million/year (assuming 10 million connections statewide)
  • $0.5/month opt-out voluntary fee (nudge) for all public drinking water system customers, raises ~$60 million/year
  • Alternatively, a local utility might choose an equivalent charge based on the greatest difference in water use over the past 12 months (usually summer minus winter use). This would largely tax outdoor water use, which is a more consumptive of water and expensive to supply, and would further shift payments from poorer households.
  • Deferring urban customer charges for 2-3 years would allow for upgrades to utility billing software and customer interface websites (for allowing opting out) and perhaps apply only to public drinking water system with more than 500 connections to ease implementation burdens on small systems.
  • $60 million/year from legislature, matching utility fee revenues (The legislature now has $430 million/year not needed for paying off the Proposition 3 water bond. The interest cost on the $1.398 billion disadvantaged community portion of that bond alone would have been about $68 million /year.)  Having a regular long-term general fund match program should allow greater efficiencies and accountability in the use of all funds.
  • Total funds raised would be about $200 million/year. $100 million/year would be allocated based on need to support lifeline water rates statewide (reducing Prop. 218 problems for public water utilities). $100 million/year would be allocated to making safe drinking water supplies accessible in rural areas.
  • Of the amount for rural systems, initially $40 million/year would be allocated for counties and water districts to fund small system consolidations. Consolidations often are the best way to permanently solve major rural drinking water system problems. Ideally consolidations occur by pipeline connections (often with additional small system upgrades).  Where consolidation by connection is prohibitively expensive, administrative consolidations of distributed drinking water systems, perhaps under county-wide service districts, can provide more organized attention and administrative economies of scale.

Some Further reading

Canada, H., K. Honeycutt, K. Jessoe, M. W. Jenkins, and J. R. Lund. 2012. Regulatory and Funding Options for Nitrate Groundwater Contamination. Technical Report 8 in Addressing Nitrate in California’s Drinking Water with a Focus on Tulare Lake Basin and Salinas Valley Groundwater. Report for State Water Resources Control Board Report to the Legislature. University of California, Davis, Center for Watershed Sciences.

Ellis, R. (2018), “New bill proposes to fix water quality for less than pennies on the dollar”, The Sun-Gazette, August 29, 2018

Garibay, V. and C. Tuck (2018), “Pro-con: A new tax to provide clean water?,” CalMatters, Aug. 24, 2018

Hanif, M., “Let Them Drink Bottled Water,” New York Times, opinion, Nov. 23, 2018

Honeycutt, K., H. Canada, M. W. Jenkins, and J .R. Lund. 2012. Alternative Water Supply Options for Nitrate Contamination. Technical Report 7 in Addressing Nitrate in California’s Drinking Water with a Focus on Tulare Lake Basin and Salinas Valley Groundwater. Report for the State Water Resources Control Board Report to the Legislature. University of California, Davis, Center for Watershed Sciences.

Kasler, D., R. Sabalow, and A. Koseff “Gavin Newsom budget calls for drinking water tax to help poor communities,” Sacramento Bee, 11 January 2018.

Lund, J. (2017) Nudging Progress on Funding for Safe Drinking Water,, December 24, 2017 (republished by Water Deeply)

SB 844 and SB 845 texts from 2018:

Sabalow, R., L. Griswold and B. Anderson, “Did gas, homeless people and sick kids kill California’s water bond?,” Sacramento Bee, November 09, 2018

SWRCB, website on water rate assistance program.

Jay Lund is a Professor of Civil and Environmental Engineering and Director of the Center for Watershed Sciences at the University of California, Davis

Posted in Uncategorized | 4 Comments

Functional Flows for Developing Ecological Flow Recommendations

by Sarah Yarnell, Alyssa Obester, Ted Grantham, Eric Stein, Belize Lane, Rob Lusardi, Julie Zimmerman, Jeanette Howard, Sam Sandoval-Solis, Rene Henery, and Erin Bray

To protect California’s native aquatic species, stream flows need to be managed to support important ecological processes and habitat needs.

In practice, such flows are difficult and controversial to define and implement. Water diversions, dams and other water infrastructure, land drainage, and changing climate conditions have altered the timing and availability of water, creating demands that impair restoration of the full natural flow regime. While restoring full natural flow regimes in California rivers may not be possible, preserving key aspects of the flow regime, or functional flow components, may provide a means to conserve the state’s freshwater ecosystems.

What are functional flows?

The functional flows approach provides a basis for estimating how much water is needed for the environment, where key components of the natural flow regime are targeted rather than the full natural flow regime. Desirable functional flow components have a disproportionately important role in supporting the physical and ecological processes that create and maintain habitat and trigger native species to reproduce, thrive, and migrate.

A natural versus functional flow regime. The functional flow regime preserves key aspects of the natural hydrograph. From Yarnell et al. 2015.

This process-based approach preserves the most important aspects of the variability of a natural flow regime to which native species have adapted.  It differs from environmental flow methods that focus on single species and their habitat requirements by instead capturing the needs of biological communities.

Most rivers in California have four functional flow components of the natural flow regime represent significant drivers of geomorphic and ecological processes:

  1. Wet-season initiation flows, or the first major storm event following the dry season. These flows represent the transition from dry to wet season, and serve important functions such as moving nutrients downstream and signaling species to migrate or spawn.
  2. Peak magnitude flows, which transport a significant portion of sediment load and maintain and restructure river corridors.
  3. Spring recession flows, which signify the transition from high to low flows and provide reproductive and migratory cues and redistribute sediment.
  4. Dry-season low flows, which favor native species adapted to withstand stressful periods.

Each of these four components are quantified by flow characteristics, including magnitude, timing, duration, frequency, and rate of change. Together, these aspects of flow comprise a functional flow regime; no single component or characteristic alone constitutes a functional flow regime. The relative importance of functional flow components may vary locally, while flow characteristics will likely vary based on water year type (dry, moderate, wet conditions). Year-to-year hydrologic variability provides periodic disturbances needed to support diverse aquatic and riparian communities. Additionally, characteristics should remain similar to natural values observed historically in order to protect native species and ecological processes.

Functional flow components are quantified using relevant flow characteristics linked to geomorphic and ecological processes.

While the functional flows approach can help estimate environmental water needs, it may not by itself provide a solution to ecosystem recovery. Additional physical habitat restoration may be required to realize the full benefits of a functional flow regime. For example, channel floodplain connections may be needed to support benefits of high flows that provide habitat diversity. Additional management measures may be needed to address a spectrum of water quality concerns in a watershed, including stream temperature, nutrients, sediment, and dissolved oxygen. These factors should be considered and explored further when utilizing a functional flows approach. Chapman et al. (2018) illustrate the success of this type of approach for Putah Creek, California.

How could this approach be applied in a management context?

A recent PPIC report recommended establishing an ecosystem water budget, which would allocate a block of water to the environment. Such budgets would bring the environment to the table as a partner in water management and allow for the trustee responsible for managing that water budget to participate in buying and selling water.

The functional flows approach provides a strategy for defining and allocating ecosystem water budgets. For example, by quantifying the functional flow components for a particular system, they can be aggregated to estimate an annual ecosystem water budget. Once budgets are established, they can also be used to guide when environmental water allocations are necessary to achieve targeted flow functions, for example by releasing water from dams at critical times to increase peak winter flows, or by curtailing water diversions to ensure that summer baseflows remain within the targeted range required for ecosystem health. An ecosystem water budget informed by a functional flows approach also offers flexibility during changing conditions (wet and dry years) by providing context to consider seasonal or interannual differences in allocations that can balance ecological and human use.

Hypothetical functional flow regimes in a California river in wet and dry years. Initial environmental water budgets for different water year types are computed as the annual volume of water required to meet functional flow requirements.

The functional flows approach offers a flexible means of informing flow recommendations that capture significant processes upon which native species are hypothesized to depend. This approach could be an effective way to manage an ecosystem water budget for California that preserves important components of the natural flow regime.

Sarah Yarnell is a senior researcher and Alyssa Obester is a researchers at the UC Davis Center for Watershed Sciences. Ted Grantham is faculty at the University of California, Berkeley, and an affiliate of the Center for Watershed Sciences. Eric Stein is a Principal Scientist at Southern California Coastal Water Research Project. Belize Lane is faculty at Utah State University. Rob Lusardi is also a researcher at the Center for Watershed Sciences and is the UC Davis-California Trout Coldwater Fish Scientist. Julie Zimmerman and Jeanette Howard are affiliated with the Nature Conservancy. Samuel Sandoval is an Associate Professor in the Dept. of Land, Air and Water Resources at UC Davis and an UC Agricultural and Natural Resources Cooperative Extension Specialist. Rene Henery is with Trout Unlimited. Erin Bray is faculty at California State University, Northridge. These individuals are continuing to work on implementing a functional flows approach across California via the Environmental Flows Workgroup, a sub-group of the California Water Quality Monitoring Council. Stay tuned for upcoming related blogs.

Further Reading

Chapman, E., E. Jacinto, and P. Moyle (2018). Habitat Restoration for Chinook Salmon in Putah Creek: A Success Story. California Water Blog.

Jeffres, C. (2011). Frolicking fat floodplain fish feeding furiously. California Water Blog.

Mount, J., Gray, B., Chappelle, C., Gartrell, G., Grantham, T., Moyle, P., Seavy, N., Szeptycki, L., and Thompson, B. (2017). Managing California’s Freshwater Ecosystems: Lessons from the 2012–16 Drought. Public Policy Institute of California.

Poff N.L., Allan J.D., Bain M.B., Karr J.R., Prestegaard K.L., Richter B.D., Sparks R.E., Stromberg J.C. (1997). The natural flow regime. BioScience 47: 769–784.

Yarnell, S.M., Stein, E.D., Lusardi, R.A., Zimmerman, J., Peek, R.A., Grantham, T., Lane, B.A., Howard, J., and Sandoval-Solis, S. (2018). An ecologically based approach for selecting flow metrics for environmental flow applications. In Review. Journal of Ecohydraulics.

Yarnell, S. M., Petts, G. E., Schmidt, J. C., Whipple, A. A., Beller, E. E., Dahm, C. N., … Viers, J. H. (2015). Functional Flows in Modified Riverscapes: Hydrographs, Habitats and Opportunities. BioScience, biv102.

Willis, A. (2018). The folly of unimpaired flows for water quality management. California Water Blog.

Posted in Conservation, Planning and Management, Water Markets | Tagged , , | 4 Comments

The folly of unimpaired flows for water quality management

Canyon section of the Shasta River in the late fall when spawning Chinook return and the focus of a water transfer program to address water quality conditions. Photo: Carson Jeffres

by Ann Willis

Unimpaired streamflow has long been the benchmark against which current stream flows are evaluated for environmental purposes. The underlying assumption is that if there is water in a stream, the stream must be healthy.

A closer look shows why unimpaired flows is often a flawed basis for environmental management, particularly when water quality is the primary problem.

Environmental flow studies seem ubiquitous. In California’s Shasta River watershed, a tributary to the Klamath River, unimpaired flows have been the basis of recent Instream Flow Needs studies. Recently, another study uses unimpaired flows for a larger regulatory effort to address California’s Water Action Plan.

The approach in the draft Shasta River study plan follows a familiar pattern: first, develop a flow model to better understand current water supply, water demand, and instream flow patterns. Then, remove all human activity (e.g., diversions, pumping, storage) to estimate unimpaired flows. Ultimately, use the model to evaluate water management scenarios that address ecosystem objectives – in California, these ecosystem objectives frequently focus on anadromous fish such as salmon.

At first, such an approach seems reasonable and systematic. However, a regulatory strategy built on unimpaired flows makes critical assumptions on how streams work; assumptions that seem increasingly invalid.

Four questionable assumptions form the basis of many unimpaired flow strategies:

  1. Today’s unimpaired flows would support anadromy and native fish.

Because salmon thrived in rivers before European settlers diverted flows for mining/agriculture/etc, many assume that they would thrive again if diversions stopped today. Many streams have had too much water diverted for too long, resulting in a persistent environmental drought. But unimpaired flows do not guarantee that other vital conditions exist for fish to thrive (like desirable stream temperature, dissolved oxygen, or nutrient levels). Further, climate change has already influenced a variety of physical and ecological conditions, including the timing of flows as snowmelt shifts earlier to rainfall runoff.  Thus, even if we could restore unimpaired flow patterns to our streams, historical conditions may no longer be a realistic benchmark for current or long-term management.

  1. Water temperature and water quality problems are changed by instream flow management.

Stream temperature is a major characteristic of aquatic habitat. It drives water quality processes, food webs, animal health, reproductive success, and much more. Stream temperature is naturally influenced in many ways.  Developing a management strategy for stream temperatures requires understanding the processes that drive those temperatures.

Aquatic plants form a natural canopy in Big Springs Creek, and control water temperatures during mid- to late-summer.

In the Shasta River, the things that drive temperature change as the river flows downstream. In some areas, aquatic plants control water temperature. In other places, stream temperatures are controlled by large groundwater springs far upstream that overwhelm other local influences, including diversions (similar phenomenon have been observed downstream of large dams, too). Eventually, water flowing on the surface reaches a balance with surrounding air temperature. In these situations, more water does little to influence temperature (or other water qualities), so unimpaired flows often fail to address undesirable temperature.

Generally, stream flow and water temperature are inextricably linked. But for stream temperature problems, flow-based management strategies is not always the right approach.

  1. Watershed-scale models provide detailed insights for managing localized water temperature and water quality.

Fish management is as much a question of water quality as it is water quantity. Often, the data needed to understand and model these processes is highly detailed and covers many features.

Watershed models look at large areas, when the true areas of interest may only be a few key places. The Shasta Basin (outlined) is part of the much larger Klamath Basin (inset). Source: UC Davis Center for Watershed Sciences

Watershed models are the 30,000-ft view of these processes. Modelling an entire watershed to develop a management strategy specific to anadromous fish and water quality issues is like using a wide-angle lens when you really need a magnifying glass.

Local actions have local results that are often lost in a watershed-scale model. Cumulatively, many local actions may be needed to mitigate basin-scale problems. But the right combination of specific, effective local actions can only be identified on a more detailed scale than can be shown by a watershed-scale model. Figuring out where the priority areas are depends on a dedicated investigation to understand the underlying processes, which leads to myth #4:

  1. “Best available data” will be enough to develop effective, watershed-wide regulatory management.

Regulators are in the unfortunate position where they must implement regulatory policies, but can only implement effective strategies on the “best available data.” The “best available data” may be insufficient to define the underlying stream processes that prompt regulatory actions. Nevertheless, agencies are mandated to regulate, whether or not data is available to develop effective strategies.

Generally, no one benefits from a poor understanding of stream processes. Science brings vital insights that are necessary to manage our resources, including what data we can afford to forgo and what data we cannot. The scientific studies funded as part of Proposition 1 are good examples of how public investment can realize public benefit through well-informed scientific findings. But Prop 1 science funding is limited to the Delta.  Proposition 68 focuses on projects in California’s rivers and streams, including the Klamath, but has no comparable funding category for scientific studies of those areas.

The Klamath watershed, though geographically remote, has already seen regulatory and litigation decisions that have profound implications for the rest of California, including the Delta. Though the short-term result of robust public funding for watersheds like the Shasta and Klamath may be an uncomfortable admission of how poorly we have understood our rivers and streams, in the long-term we provide more stability to all water users and more effective guidance to regulatory policies. A step away from unimpaired flows as a default framework for managing our streams would be a step in the right direction.

Ann Willis is an engineer at the Center for Watershed Sciences and PhD student in Civil and Environmental Engineering at U.C. Davis. Her work is currently supported by fellowships with the National Science Foundation (Graduate Research Fellowship Program) and the John Muir Institute for the Environment.

Further readings

Paradigm Environmental. 2018. Draft Shasta River Watershed Characterization and Model Study Plan.

Willis et al. 2017. Seasonal aquatic macrophytes reduce water temperatures via a riverine canopy in a spring-fed stream.

Nichols et al. 2014. Water temperature patterns below large groundwater springs: management implications for coho salmon in the Shasta River, California.

Willis et al. 2015. Instream flows: new tools to quantify water quality conditions for returning adult Chinook salmon.

Posted in California Water | Tagged , , , , , | 4 Comments

Striped Bass in the San Francisco Estuary: Insight Into a Forgotten Past

A typical commercial fishing boat of the 1920s, drifting gill nets upstream of Carquinez Strait. Fisherman would often spend multiple days on the water, unloading their daily catch on “pick up” boats operated by SF fish dealers. Photo: W.L. Scofield, 1926.

by Dylan Stompe and Peter Moyle

Striped bass are well known throughout California as a hard-fighting game fish, excellent table fare, and a voracious predator on other fish. Striped bass were introduced into the San Francisco Estuary in 1879 and are often cited as a major cause of native species decline. Historically they were valued as a strong indicator of estuary health, as well as a very important game fish. In fact, key ecological monitoring programs in the estuary were established in the 1950s and 60s to keep track of striped bass populations.

Because striped bass are one of California’s best-studied fish species, there is an abundance of historical data regarding their abundance, distribution and diet. By tapping into this information we can build a better understanding of California striped bass life history and historical trends, and better understand their role in the San Francisco Estuary ecosystem.

We have recently embarked on a project reviewing the life history, biology, and status of striped bass within California waters, as compared to their native waters of the East Coast. Through our plunge into the historical literature, we have uncovered a series of largely forgotten facts about striped bass which we present here as a brief quiz. Answer the questions below to test your knowledge of California striped bass. Consider yourself an expert if you get 7 of the 10 answers right. Answers are at the end of the blog.

  1. From which state did California’s striped bass originate?

a. North Carolina

b. New York

c. New Jersey

d. Connecticut

2. Approximately how many striped bass were introduced to the San Francisco Estuary?

a. 15

b. 145

c. 435

d. 1505

3. When was the first striped bass caught on the West Coast outside San Francisco Bay reported?

a. 1880

b. 1882

c. 1887

d. 1892

4. In what year did the commercial fishery begin in earnest for striped bass in California?

a. 1880

b. 1889

c. 1893

d. 1900

5. In 1893-1894 what was the average weight, in pounds, of striped bass sold in the San Francisco fish markets? (N = 1,461)

a. 1

b. 3

c. 7

d. 11

e. 15

6. What were the main fish consumed by adult striped bass in the San Francisco estuary in the 19th century?

a. Delta Smelt

b. Chinook Salmon

c. Juvenile Striped Bass

d. Native Minnows

e. Common Carp

7. In which river were striped bass most common in the 19th century?

a. Mokelumne

b. San Joaquin

c. Sacramento

d. American

e. Feather

8. What’s the unofficial largest striped bass to have been caught by hook and line in California (to the nearest pound)?

a. 45

b. 68

c. 74

d. 88

e. 95

9. In what year were statewide regulations first adopted for the protection of the striped bass fishery in California?

a. 1905

b. 1909

c. 1916

d. 1920

e. 1922

10. What was cited as the initial cause of striped bass population decline in California waters?

a. Altered Flow Regimes

b. Entrainment in Pumps

c. Pollution

d. Prey Decline/Change in Prey

e. Commercial Fishing

Observations on the historical diet, abundance and distribution of striped bass give us a better understanding of estuary conditions in the past. For example, their apparent preference for carp as prey in the late 1800s indicates that other non-native species were already abundant in the system. It also suggests that the bass were feeding on the bottom, in shallow, turbid water. Likewise, the apparent change of preference in rivers for spawning from the San Joaquin to the Sacramento in the 20th century is another indicator of changing river conditions from a time when flow and water quality data is sparse.

An 87.5lb striped bass, caught in San Antonio Creek by Charles R. Bond in 1912. San Antonio Creek is a small tributary to the Petaluma River in Petaluma, California. Photo courtesy of the Marin Rod and Gun Club.

The changes in attitude of people towards this fish are also instructive. Striped bass started as a much-heralded introduction to provide a familiar and prized fish for the tables of residents of the SF Bay region. Its population explosion resulted in a huge commercial fishery, which was eventually abandoned in favor of the sport fishery.

By the 1930s, it was revered by all as one of the best game fishes in California, for both sport and table. By the 1960s, it was recognized as an abundant, but probably declining, species, in part because of changing conditions in the estuary. This resulted in flow regulations to protect the bass and monitoring programs to track their abundance.

In the last 10-15 years, the management paradigm has shifted again: striped bass are now regarded as an alien invader that suppresses populations of declining salmon and smelt, despite its concurrent population decline and value as a game fish. Perhaps this paradigm should be reconsidered: should we instead treat striped bass as a sentinel species to provide insights into the condition of the SF Estuary?

Regardless of your own opinion of California striped bass, it is clear that there is value in understanding its history and gaining insights into the SF Estuary’s ecosystem that this much-studied species affords.

Dylan Stompe is researcher at the Center for Watershed Sciences, studying the abundance, distribution and life history of striped bass in the San Francisco Estuary. Peter Moyle is Distinguished Professor Emeritus at the University of California, Davis and Associate Director of the Center for Watershed Sciences.

Further reading

Scofield, Eugene. 1931. The Striped Bass of California (Roccus lineatus)California Division of Fish and Game Fish Bulletin 29:  84 pp.

Scofield, N. and H. Bryant. 1926. The Striped Bass in California. California Fish and Game 12 (2) :55-74

Smith, Hugh. 1895. The Striped Bass History and Results of Introduction. U.S. Fish Commission Bulletin. Vol 15.

Quiz Answers:

  1. C; The first introduction was sourced from the Navesink River and the second from the Shrewsbury River. Although separate rivers, they both drain into the same estuary and may have been effectively the same population.
  2. C; 435: 135 in the first introduction, 300 in the second.
  3. A; An eight inch bass was reported to have been caught in Monterey Bay, just 6 or 7 months after the first introduction. The first confirmed report in SF Bay occurred several months after that.
  4. B; The commercial fishery quickly ramped up to a maximum harvest of 1.8 million pounds in 1915. The commercial fishery was then banned in 1935 in favor of the growing recreational fishery.
  5. D; Average sizes were dependent on month of capture, with a range of 7 to 14 pounds during this time period.
  6. E; Anecdotal accounts from bass examined both in the fishery and in the fish market indicated that carp were a major prey of bass of all sizes. Carp were introduced to California seven years prior to striped bass, in 1872, and presumably were experiencing their own population explosion.
  7. B; There are many observations of aggregations of striped bass in the San Joaquin River, apparently for spawning, in the 19th and early 20th centuries. In contrast, commercial salmon fishermen in the Sacramento River rarely reported catching striped bass during the same time period.
  8. D; On the wall of the Marin Rod and Gun Club is a picture of an 87.5 lb striped bass caught in a tributary to the Petaluma River in 1912.  The current IGFA world record of for striped bass of 81.88lbs was caught in 2011 in Connecticut
  9. B; A ban on export of striped bass from California, as well as a ban on commercial fishing for striped bass during spawning season, was adopted in 1909. Regulations became stricter after a record harvest in 1915, in part due to pressure from recreational anglers.
  10. E; While the fishery was blamed for the decline from the days of super-abundance, even early observers thought multiple factors were involved, including dams, water diversions and pollution.
Posted in Delta, Fish, Sacramento-San Joaquin Delta | Tagged , | Leave a comment

Eastern San Joaquin Valley and other CA drinking water supplies at risk in the next drought

Donna Johnson, 70, (L) lifts pallets of donated bottled water from the back of her truck during her daily delivery run to residents whose wells have run dry, with resident Gabriel Tapia, 31, in Porterville, California October 14, 2014. Picture taken October 14, 2014. REUTERS/Lucy Nicholson

by Amanda Fencl, Rich Pauloo, Alvar Escriva-Bou, Hervé Guillon

During the 2012-2016 drought, the state received more than 2,500 domestic well failure reports, the majority of which were in the Central Valley (DWR 2018). This left thousands of people without a reliable source of drinking water for months and, in some cases, years. The crisis drew national attention as well as local and state investment and intervention in many communities.

The next drought might be just around the corner, pushing farmers and cities to pump more water from the ground again, and risking the primary water source for the estimated 1.44 million Californians that rely on domestic wells for drinking water and household use (Dieter et al. 2018). These people are responsible for maintaining their own water supply; during droughts, they are “first to suffer […] in cabins in Modoc County, among  … the hills of Paso Robles, in the farmworker towns of the San Joaquin Valley” (Santa Cruz Sentinel 2014). Would we be ready to deal with the next crisis? Can we plan in advance to avoid such problems?

One of the ways to be better prepared is by strengthening rural drought resilience and identifying who is at risk and vulnerable to experiencing domestic well failure. As part of the 2018 #CAWaterDataChallenge, our team created a  tool-oriented research product that addresses three specific questions:

  •       Which domestic wells will be vulnerable in the next drought?
  •       Are disadvantaged households disproportionately affected by drought-vulnerable       wells?
  •       Can we identify characteristics of the vulnerable wells that will worsen with climate change?

Our submission was driven by open data from public agencies and assessed the vulnerability of domestic wells to failure in the Central Valley.  Using the Department of Water Resources’ (DWR) seasonal groundwater level measurements, we interpolated groundwater levels in the shallow to semi-confined Central Valley aquifer system. Then, a spatial model of well failure was built and calibrated to actual, reported well failures collected by the state during the 2012-2016 drought (DWR 2018).  The spatial point pattern of our model’s predicted well failure during the 2012-2016 drought matched observed well failure point patterns reported to the state as dry or failing wells.

Which domestic wells will be vulnerable in the next drought?

Assuming no interim intervention to resolve existing or prevent new well failures, our project shows where domestic wells are vulnerable in future droughts.   A well fails when the groundwater level in a drought scenario falls below the level of the pump. We simulate 1-, 2-, 3-, and 4-year-long droughts by scaling the observed (2012-2016) 4-year groundwater level change. Due to already low groundwater levels, a simulated a 4-year-long-drought starting in January 2018 would result in more than 4,000 domestic well failures in the Central Valley alone, nearly twice as many well failures compared to 2012-2016. The eastern San Joaquin Valley (especially Fresno, Tulare and Madera counties) and small areas in northern basins are the most susceptible to domestic well failure.

Are disadvantaged households disproportionately affected by drought-vulnerable wells?

To understand the socio-economic conditions of those impacted by well failure, we assign 2016 census block group Median Household Income values to domestic wells located within that block group. We then calculate the distance between failed wells and the nearest community water system. Initial findings indicate that 2012-2016 drought disproportionately impacted domestic wells found in low-income areas.  About 1.5 times more well failures were reported by households in disadvantaged and severely disadvantaged communities (DAC + SDAC together) compared to those at or above the Median Household Income (MHI+).

Additionally, more than half of the well failures in SDACs were less than one mile from the nearest water system, suggesting that connecting households with failed wells to a nearby water system is a potential long-term solution.  Many households with domestic wells that failed are isolated and rural, as shown by the points in this box plot, and anywhere from 2.5 – 7.5 miles from their closest community water system.

Can we identify characteristics of the vulnerable wells that will worsen with climate change?

Results from the spatial model of well failure were used to train an ensemble machine learning classifier on 56 climatic and geologic variables to predict present day well failure across the Central Valley and assess the climatic controls on domestic well failures.  Preliminary results indicate that well failure is associated with higher temperatures in the spring, fall, and summer. This work is ongoing and will be further refined to identify which areas will likely be most at risk in the future; providing information for policymakers and stakeholders to make informed decisions in preparations for the next drought.  

We can’t avoid another drought in California. But we can work to anticipate its potential impacts, plan proactively, and avoid its consequences. Our research provides a framework to deal with one of the worst effects of the latest drought –  thousands of people running out of water in one of the richest regions of the world. Our hope is to show local and state decision-makers what is possible with existing data and methodologies to proactively address drinking water issues in California’s rural communities.

We are grateful to the organizers and champions of the 2018 #CAWaterDataChallenge for their support and recognition of our project.

Rich Pauloo presenting the project (L) and accepting (R) an award for most Data-licious submission and special recognition for the Ready-to-Go award at the Oct 18th award ceremony.

Amanda Fencl is a PhD Candidate in Geography and Rich Pauloo is a PhD Candidate in Hydrology at UC Davis; both are UC Davis NSF IGERT trainees.  Dr. Hervé Guillon is a Postdoctoral Scholar at the UC Davis Water Resources Management Group and Dr. Alvar Escriva-Bou is a Research Fellow at the Public Policy Institute of California.

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Getting Strategic about Freshwater Biodiversity Conservation in California

Pacific giant salamander (Dicamptodon ensatus) – The Pacific giant salamander is the largest terrestrial salamander in North America and is one of several salamanders that have vocal abilities.

by Jeanette Howard, Kurt Fesenmyer, Theodore Grantham, Joshua Viers, Peter Ode, Peter Moyle, Sarah Kupferberg, Joseph Furnish, Andrew Rehn, Joseph Slusark, Raphael Mazor, Nicholas Santos, Ryan Peek, and Amber Wright

An essential first step to protect biodiversity is understanding what species are present in a region, where they can be found, and their conservation status. For freshwater organisms in California, this information has been difficult to gather because sampling data are collected by many different entities and have been stored in disparate databases.

But now, a large number of freshwater biodiversity datasets have been assembled to guide strategic conservation planning for the numerous plants and animals that find a home in the state’s rivers, lakes, ponds, and wetlands. “Big Data” has arrived in the form of the PISCES database, which includes range information for all of California’s freshwater fishes; open access to global biodiversity museum records; eBird and other citizen science data collections; and the aggregation of local freshwater bioassessments into the Surface Water Ambient Monitoring Program (SWAMP) database.

To provide a comprehensive inventory of freshwater dependent species, these and other datasets have been compiled into a statewide repository. A new California Freshwater Species Database contains information on 3,906 vertebrates, macroinvertebrates, and vascular plants native to California and that depend on fresh water for at least one stage of their life history. This database has enabled a better understanding of the patterns of freshwater species richness, endemism, and vulnerability in California. The database also provides the foundation for a statewide Freshwater Conservation Blueprint, which for the first time systematically identifies priority watersheds for native freshwater biodiversity management and conservation across California.

Conservation Planning – Putting the Information to Work

Western pearlshell mussel (Margaritifera falcata) – The western pearlshell mussel have life spans up to 100 years and depend on fish hosts for larval development.

Although the loss of terrestrial biodiversity garners much attention, freshwater species are at the forefront of the global extinction crisis. Species dependent on freshwater habitats are in decline globally (Dudgeon et al. 2006) with between 10,000 and 20,000 freshwater species thought to be extinct or imperiled. In California, nearly half of the state’s native freshwater taxa and 90% of the state’s endemic taxa are vulnerable to extinction, with 11 freshwater species considered extinct (1 plant, 2 crustaceans, 1 mollusk, 1 frog, 6 fishes) and 14 possibly extinct (8 insects, 2 amphibians, 1 turtle, 1 mollusk, 2 plants). Moreover, estimates of extinction rates are considered underestimates because freshwater organisms are understudied (Abell 2002).

 Scientists have long been aware that conservation of freshwater biodiversity faces severe challenges. The fragmented nature of freshwater habitats often results in high levels of endemism, making freshwater populations highly vulnerable to extirpation (Strayer and Dudgeon 2010). In addition, efforts to conserve freshwater species are often stymied because protected areas typically reflect jurisdictional/landscape boundaries that have little meaning for aquatic species. For example, an assessment of conservation priority areas for California’s freshwater fishes found that there was little overlap with the state’s existing protected area network (Grantham et al. 2016),  indicating that improved management of both private and public lands is needed to conserve native fish species.

Pacific tree frog (Pseudacris regilla) has a remarkable wide geographic range from Baja to southern British Columbia and inland to parts of Idaho, Nevada and western Montana. This frog is so adaptive that you can find them in your backyard, along the beach, in the Mojave Desert, grasslands and even at 11,000 feet on Mount Whitney.

Efforts to protect freshwater species are often stymied because protected areas typically reflect jurisdictional/landscape boundaries that have little meaning for aquatic species. For example, an assessment of conservation priority areas for California’s freshwater fishes found that there was little overlap with the state’s existing protected area network (Grantham et al. 2016),  indicating that improved management of both private and public lands is needed to conserve native fish species.

Grantham et al.’s effort has recently been expanded to identify watersheds of high conservation value for a broader range of freshwater species. Led by Jeanette Howard of The Nature Conservancy in collaboration with scientists from the state, federal, academic, and NGO community, we used a conservation planning tool to identify an efficient network of priority conservation watersheds for California’s fishes, frogs, salamanders, snakes, and turtles – the ‘target taxa’. The planning tool first identifies watersheds where the majority of land area or perennial stream mileage has a management mandate emphasizing biodiversity – ‘existing protected areas’ such as national parks – and then incorporates a network of additional watersheds where the most taxa co-occur and where rare taxa are present.

Priority conservation areas. The network is comprised of watersheds with a fish, amphibian or reptile target species present and at least 75% of the watershed area or stream network in a protected area (USGS Gap Analysis Program status 1, 2; green watersheds), and watersheds that best complement these protected areas based on species present (purple watersheds). The network is constructed in a way that maximizes the number of species and proportion of those species’ ranges included, while minimizing the area of the network.

The assessment was recently published in an article in Freshwater Science (Howard et al. 2018) and outlines a Freshwater Conservation Blueprint for California. The Blueprint delineates a comprehensive, representative, and efficient freshwater conservation network that covers around 1/3 of the land area of California (Figure 1) – yet includes at least 10% of the range of all target taxa.  This area is comparable in size to existing protected areas, but provides more “bang for the buck” in conserving freshwater biodiversity because many target taxa are absent from existing protected areas.

More importantly, ~70% of the freshwater conservation network occurs on public lands managed for multiple purposes such as grazing, logging, and recreation.  These lands are largely those of the US Forest Service and Bureau of Land Management, where small changes in management could provide substantial benefits to freshwater biodiversity.

The Blueprint provides strong evidence for compatible management of aquatic biodiversity on multi-use public and private lands. Maps of priority conservation areas are available online via California Department of Fish and Wildlife’s BIOS tool, and we have developed an online decision support tool for evaluating impairments, threats, and potential conservation actions within the priority areas.

How This Blueprint Can Be Used

The goals of the Freshwater Blueprint for California are to help improve the efficiency of on-going and planned conservation efforts and accelerate progress towards effective, long-term preservation of the state’s freshwater biodiversity.

Longhorn fairy shrimp (Branchinecta longiantenna) – an federally listed endemic crustacean to California where there are only four known populations.

The proposed conservation network is intended to identify watersheds where management actions can be prioritized to conserve native freshwater biodiversity. We don’t envision the state establishing a new reserve network – rather, the objective is to create a more coherent and targeted approach to freshwater conservation.

Limited resources require strategic action to conserve freshwater taxa currently represented within protected areas and to preserve biodiversity hotspots that primarily occur outside reserve boundaries. Because priority catchments within and outside protected areas are threatened by climate change and other stressors, conservation will require reconciliation approaches to create the best possible conditions for freshwater fishes in altered environments within existing management regimes (Moyle 2013).

There is growing evidence that conservation of freshwater biodiversity is compatible with human uses. For example, efforts to restore flows in Putah Creek via dam releases and the Shasta River through changes in agricultural irrigation practices have resulted in improved conditions for native fishes without adversely affecting primary human uses. Restoring floodplain connectivity in human-dominated landscapes through managed floodways, offseason flooding of fields, or active levee breaching, have been shown to provide multiple ecosystem benefits, reduce flood risk, and sustain floodplain agriculture. By guiding the strategic implementation of such management approaches, the Freshwater Conservation Blueprint can help bring ecosystem reconciliation to scale and ensure the long-term preservation of the state’s freshwater biodiversity.

We emphasize that while the Blueprint lays the broad groundwork for a conservation strategy, it is not meant to diminish more localized conservation efforts that are outside the designated areas.  All the species covered by the Blueprint need multiple populations to thrive. Thus, smaller refuges outside those designated in the Blueprint are always important.  This is one reason why statewide monitoring programs are needed to continually expand and update the database to track the changes in the range and abundance of freshwater species. With good data and a strategic approach, we can reverse the trends of biodiversity loss and safeguard the future of our state’s freshwater species.

Jeanette Howard is the Director of Science for the Water Program at the Nature Conservancy. Kurt Fesenmyer is the GIS and Conservation Planning Director with Trout Unlimited. Ted Grantham is faculty at the University of California, Berkeley, and an affiliate of the U.C. Davis Center for Watershed Sciences. Josh Viers is faculty at the University of California, Merced, and an affiliate of the Center for Watershed Sciences. Peter Ode is affiliated with the Aquatic Bioassessment Laboratory at the California Department of Fish and Wildlife. Peter Moyle, Nicholas Santos, and Ryan Peek are affiliates of the Center for Watershed Sciences. Sarah Kupferburg is with Questa Engineering. Andrew Rehn and Joseph Slusark are affiliates of the Aquatic Bioassessment Laboratory, California Department of Fish and Wildlife, and Center for Water and the Environment—California State University, Chico. Raphael Mazor is affiliated with the Southern California Coastal Water Research Project. Amber Wright is faculty at the University of Hawaii, Manoa.

Further reading

Howard JK, et al. 2018. A freshwater conservation blueprint for California: prioritizing watersheds for freshwater biodiversity. Freshwater Science. 37(2):417-31.

Strayer DL, Dudgeon D. 2010. Freshwater biodiversity conservation: recent progress and future challenges. Journal of the North American Benthological Society. 2010; 29: 344–358.

Dudgeon D et al. 2006. Freshwater biodiversity: importance, threats, status and conservation challenges. Biological Reviews. 81: 163–182.

Abell R. 2002. Conservation biology for the biodiversity crisis: a freshwater follow-up. Conservation Biology. 16(5): 1435–1437.

Grantham, TE, et al.  2017. Missing the Boat on Freshwater Fish Conservation in California. Conservation Letters. 10: 77-85.

Howard JK, et al. 2015. Patterns of Freshwater Species Richness, Endemism, and Vulnerability in California. PLoS ONE. 2015; 10(7): e0130710.

Moyle, P.B. (2013). Novel aquatic ecosystems: the new reality for streams in California and other Mediterranean climate regions. River Res. Appl., 30, 1335-1344.

Posted in Biology, California Water, Conservation, reconciliation | Tagged | 1 Comment