Some more water management truisms (Part II)

by Jay Lund

Fate of old professors

Decaying matter from which truisms emerge

Here is part two of a partial collection of truisms on water management.  These ideas seem obviously true, but still offer insights and perspective.  Original sources are mostly unknown (but apocryphal citations are common).  Any that I think are original to me, are probably not.

  1. Progress and effectiveness occur somewhere between complacency and panic. Complacency never befriends progress.  Panic can be motivating, but often betrays improvement.
  2. Everyone wants a better water system, and everyone agrees someone else should pay for it.
  3. Integration is easy to say, but is hard to do. So “integration” is said often.
  4. Involvement is not integration, but can be a start.
  5. You touch everything when you touch water. And in the American West, when you touch water, someone will become defensive.
  6. Some import drinking water from Fiji, Italy, or France, but not to irrigate crops.  Water is heavy and expensive to move, so it is usually cheaper to move food than water.
  7. People often pollute water by adding artificial coloring (blue, green, grey, black, etc.). Water is more clearly understood without verbal turbidity.
  8. ‘The meek shall inherit the Earth but not its water rights.’ – @WaterWired (apologies to J. Paul Getty)
  9. “No single raindrop believes it is to blame for the flood.” – E. L. Kersten
  10. Water obeys physical laws immediately, far faster than human courts.

Further reading

Lund, J. “Some Water Management truisms, Part I,”,

Jay Lund is a Professor of Civil and Environmental Engineering at the University of California, Davis.  I am frightened by how many more sayings remain on my list.  (Making such lists seems a symptom of being an old professor, which is another list to publish elsewhere someday.)

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Night of the Living Dead Salmon

by Kelly Neal and Gabe Saron

Fish 1

Adult Chinook salmon carcass picked up by the Carcass Crew. Photo Credit: Kelly Neal

On a cool and misty morning somewhere south of Redding, California, jet boats roar across the tranquil Sacramento River. Armed with tridents, machetes and poleaxes, it seems akin to a scene from an action movie; except that “California Department of Fish and Wildlife” is painted on the boats. One by one, the boats peel out of formation and hole up in eddies and backwaters beside the main river channel. Then, they wait.

Once a pale shadow is spotted within the murky depths of the riverbed, someone onboard thrusts a trident into the water and sinks its barbed prongs into something fleshy. Then, they raise it back out of the water and pivot the catch toward the bow. Glistening in the morning light, covered in welts and sores with blood streaming, a creature resembling something from a horror films slaps onto the deck. The catch lands on a measuring board and the team flies into action, calling  “Fork length: 870mm, male, spawned, disk tag ready.”

It is an adult Fall Run Chinook Salmon, just past the end of its life cycle. It takes on a zombie-like appearance as it consumes its own body for energy on the journey upstream to spawn. After spawning, the fish died and continued decomposing before crossing paths with the Carcass Crew.

Aboard the jet boats, the fishy bodies are dissected in the name of science. With knives and forceps, researchers extract eyeballs and otoliths (ear stones) from the fish. Putrid carcass residue spills across the bow and splatters the boots and pants of the team. Eyeless and mutilated, the fish is clamped with a metal tag and tossed back into the current. This floating horrorshow is one example of the length that people will go to understand and protect Chinook salmon.


Salmon carcasses for dissection.  Photo credit: Kelly Neal

This fish was, despite being slaughtered after its death, one of the lucky ones. It completed its life cycle in a largely hostile landscape: it survived variable ocean conditions, slipped past salmon fishermen, and avoided Delta water diversions on its way upstream to spawn. Something of a feat since only thousands of salmon are able to make the journey homeward now, when millions once did (Gresh 2011). Its tissues bear chemical traces from the waterways and food webs that sustained it across its lifespan. Its metal tag helps researchers compute the total number of returning adults by comparing the number of tagged to recaptured carcasses. This carcass is part of a massive effort to quantify how many spawning adults return, and what helps them survive the long watery journey.

Scientists aren’t the only ones looking for salmon carcasses. All along the Pacific Coast, organisms of all trophic levels, and even the next generation of juvenile salmon, sustain themselves on nutrient-rich carcasses. In Salmon streams in Alaska and the Pacific Northwest, bears and wolves feast on carcasses and carry their leftovers into adjacent riparian forests. This enables trees to uptake the nutrients of decaying fish. Marine-derived nutrients can restructure entire forest ecosystems, and provide nutrient-limited headwaters a pathway for growth (Naiman 2009).

Fish 3

Bobcat feasts on a Chinook salmon carcass on the Sacramento River. Photo credit: Eric Holmes

In California’s Central Valley, much of the water and its nutrients are appropriated for agriculture. In 2018, the Pacific Fishery Management Council estimated 108,000 returning Chinook Salmon adults in California’s Central Valley (Pacific Fishery Management Council, 2019). Assuming the average adult Chinook Salmon weighs 20kg and contains about 5% Nitrogen, Chinook Salmon delivered roughly 126 metric tons of marine-sourced nitrogen fertilizer to the Central Valley last year. Isotopic tracing has shown that these nutrients make their way into wine grapes, and possibly other crops, irrigated from salmon streams (Moyle and Merz 2006). This Halloween, consider something truly spooky: when you prepare a fresh salad or pour a glass of Pinot Grigio, you might be giving second life to the carcass of a long dead Chinook Salmon. Cheers!

Kelly Neal and Gabe Saron are Junior Specialists at the UC Davis Center for Watershed Sciences. 

Further Reading 

Gresh T., Lichatowich, J., Schoonmaker., P. An Estimation of Historic and Current Levels of Salmon Production in the Northeast Pacific Ecosystem: Evidence of a Nutrient Deficit in the Freshwater Systems of the Pacific Northwest. Fisheries 25:1. 2000

Merz, J. and P. Moyle, Salmon, Wildlife and Wine: Marine-Derived Nutrients in Human Dominated Ecosystems of Central California. Ecological Applications 16(3) 2006.

Ogaz, Mollie, The Spawning Dead: Why Zombie Fish are the Anti-Apocalypse, October 29, 2017.

Pacific Fishery management Council. Review of 2018 Ocean Salmon Fisheries. 2019.

Pinay, G., O’Keffe, T., Edwards, R., Naiman, R., Nitrate removal in the Hyporheic Zone of a Salmon River in Alaska.” River Research and Applications 25. 2009

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The Dreamt Land by Mark Arax: We’re all complicit in California’s water follies

by Ann Willis

(Arax photo/Joel Pickford)

We are all sinners. At least, that’s the impression Mark Arax leaves in The Dreamt Land: Chasing Water and Dust Across California. What’s bold, and distinguishes this book from others about California, is that Arax grapples with a history that we’re still in the midst of creating, rather than reflecting on sins long past and easily put away as the transgressions of others. In that way, he leaves us both illuminated and uncomfortable, for we must ask ourselves: Are we complicit? Or an agent of the rigged system? For there doesn’t seem to be much safe space for innocence.

The voices that resonate through this story are not so much oft-told tales of William Mulhullond and the Owen’s Valley Water Grab or dam excesses under Floyd Dominy, though those episodes are given their due in the chapters that describe the era of extraction and rerouting of California’s waterways. Rather than dwell on overtold stories, Arax introduces new voices, including his. 

Part of what makes this book compelling and widely appealing is that Arax doesn’t shy away from his unwonkiness. His first awareness of California water was, like most people, tangential to some other part of everyday life. Arax’s grandmother pointed to irrigation ditches crisscrossing Fresno and urged young Arax to promise never to play near one, 

“…because I would lose my balance and fall in and, like the poor sons of the Mexican farmworkers, no one would hear my screams or be able to save me. The men who ran the irrigation district wouldn’t shut off the valve and drag me out until the growing season was over, she told me. When I asked her why, she said the flow of one irrigation ditch meant more to the valley than the body of one silly little boy.” (The Dreamt Land, pg. 46)

The Sacramento – San Joaquin Delta, as seen from a ship traveling through the Stockton Ship Channel on September 24, 2013. Photo by Florence Lo, California Department of Water Resources

Arax seems to rearrange fragments of childhood memories, like his grandmother’s warning or a strange tool that his grandfather kept in a drawer, as though twisting a kaleidoscope so that when they refocus, they are framed by the powers that control the flow of California’s rivers. It’s as though, with his education of California water, a secret is revealed and Arax suddenly sees his family’s history more clearly. As pieces of his heritage come into focus, Arax guides us to forces that shaped his story, showing us how his story is also ours. If we eat here, drink here, live here, we are touched by the deep state of California water. And within that deep state, there is as much indifference to us as to a silly little boy in a ditch.

Stewart and Lynda Resnick might take issue with that assessment. That’s the implication suggested in “Kingdom of Wonderful,” the chapter on a carpetbagger’s rise and success in California agriculture. While reading about growers like the Resnicks, I’m reminded of dynasties like the Rockefellers and Carnegies: families whose wealth from industrial transgressions seems distant while their philanthropic legacies endure in museums, performance centers, public land, and libraries. Woven into the Resnicks’ empire-building activities are considerable philanthropic and community programs, including an $80 million charter school serving students from the poorest towns in the West. Nevertheless, the agricultural practices underpinning such philanthropy stand in stark relief. When a billion-dollar nut harvest signals the start of inhaler season for local farmworkers who can’t drink their own tap water and reside in what neurologists call “Parkinson’s Alley,” it’s hard to accept philanthropy as proportional penance.

Arax doesn’t just level his judgement on the agricultural barons of Kern County. He dismisses any notion of bystanders’ innocence, too:

“When the rivers were content, the people were content…They had no interest in hiring engineers who could tell them at what cubic feet their rivers flowed, a science that might allow them to better prepare for the next fit of weather. In times of good nature, they cared not to be reminded of ill nature. In the desire to forget, their memories were able to play such tricks that when flood and drought returned, they were genuinely perplexed.” The Dreamt Land, pg. 171

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

From regulators down to the public, Arax holds a mirror up to all and shows us the reflection of those either willfully indifferent to over-consumption or too cowed to wield power to regulate it. The consequences of that indifference or impotence are playing out today, such as the on-going effort to raise of Shasta Dam. Part of the genius of Arax’s book is how it juxtaposes California’s settlement history with today’s conflicts. The Dreamt Land shows that California’s water war is a long game in which formidable players have staked their ground and simply wait for the right combination of opportunity and luck to press their advantage. 

Mark Arax will speak on November 18th, 4-5:30pm at the UC Davis Student Community Center multi-purpose room. You can register at the Eventbrite link. The book lecture is free and open to the entire campus community and the public. Please feel free to forward the Eventbrite invitation to others who may be interested.

Ann Willis is a researcher at the Center for Watershed Sciences and a PhD candidate in civil engineering. She holds fellowships with the National Science Foundation GFRP, John Muir Institute for the Environment, and Southwest Climate Adaptation Science Center.

Further reading

Arax, Mark. 2019. The Dreamt Land

Reisner, Marc. 1986. Cadillac Desert

Water is for fighting over? – a review of John Fleck’s recent book. California Waterblog.

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Can we understand it all?

How we get water in our homes

This is my favorite water cartoon.  It depicts how well the public (and elected officials) will ever understand how water systems work.

Today, as individuals we understand only a little about the detailed world around us (cell phones, medical technology, monetary policy, politics, international trade, law, etc.).  We operate with amazing Neolithic brains in a modern world, relying mostly on others for details.

Public education and outreach matters, of course, as seen during the drought, but our expectations must be reasonable.  In our complex society and economy, with many important distractions, most people will only learn a lot about water systems if they fail.  Civilization requires that most people not worry about water.  The cartoon signals the success of typical water systems, which allows people to think about other things.

Water professionals and managers face similar challenges from the great complexity inside the dashed water system box.  Filling in details inside the cartoon box quickly “goes fractal” with seemingly endless agencies, regulations, institutions, specialists and specialized components, and their interactions.  No one, not even dedicated water wonks, can completely understand most water systems.

Still, modern water systems have been rather successful for public health and economic prosperity.  But for everyone individually, how water gets to our homes will be an opaque or at best translucent box.  Complexity grows as water management expands to include environmental and ecological systems.  Managing this complexity becomes a struggle for managers and the society as a whole.  We can only succeed if we work well together – this struggle is the hard price of success.

Now I must return to struggling with my smarter-than-me-phone.

Jay Lund

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

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Some water management truisms, Part I

by Jay Lund

Here is a partial collection of truisms on water management.  These are common ideas that seem obviously true (particularly in the western US), but still offer insights and perspective.  The original sources of these are unknown (although apocryphal citations are common).  Any that I think are original to me, are probably not.

  1. Water flows downhill, but uphill towards money.
  2. There is rarely a shortage of water, but often a shortage of cheap water.
  3. Some water is essential to life. But too much is also unhealthy.
  4. Silver bullets tend to sink in water.
  5. Progress is when the new problems are less bad than the old problems would have become.
  6. Your water use is a “grab” and a “waste.”  My water use is a need, a nab, and a sacred right.
  7. Water is often like money and manure – if you spread it around, many good things can grow, but heaping it all in one place can cause big problems.
  8. Irrigation inefficiency can be good for aquifer water quantity, but bad for aquifer water quality, defying simple judgements.
  9. Some changes in water availability with climate change are easily expected, and some will be unexpected. We won’t know the changes exactly for decades after they have become noticeable, if ever. Changes also are unlikely to be constant, or to end.
  10. A dedication of water and land alone is slightly more likely to create a desirable ecosystem than pile of wood, steel, and concrete is to create a home or a bridge. Resources must be organized and artfully employed, as well as provided, to get what we want.
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Management’s eternal relevance

by Jay Lund

Just a brief, and slightly pedantic, blog post this week on the importance of liberal education and broad thinking for those want to solve real problems, illustrated with a bit of history.

Engineers and physical scientists will know Claude-Louis Navier from his work on the fundamental equations of fluid mechanics (the Navier-Stokes equations) (1822). These are some of the scariest equations seen in most undergraduate engineering and science educations.

But the early French engineers did not merely derive equations that we still struggle to learn and apply.  They also founded modern engineering as an approach to organized problem-solving, an approach picked up by many disciplines. As the French state was keen to rationalize (and centralize) national military and infrastructure systems, they faced many fundamental intellectual and organizational, and technical challenges. So early French engineers were as involved in construction, management, education, and policy as they were in what we too-narrowly think of today as “engineering” calculations (Langins 2004).

Navier was a bridge inspector, a developer of fundamental equations of fluid and solid mechanics, and a policy thinker on the organization and economic analysis of public works. His 1832 paper, “On the Execution of Public Works, Particularly Concessions,” Navier compares different fundamental approaches for financing public works – local funding, state funding, state funding repaid with user fees, and private concessions. We face these issues today, and always.  He also discusses the analysis and public scrutiny desirable for evaluating such proposals.  His ideas remain fundamental and of enduring relevance for all manner of water infrastructure and projects, including local and regional water projects, local projects for safe drinking water, water storage projects, water as a human right, and privatization and community ownership.  Navier’s 1832 paper is seen by some historians of economics as among the earliest formal work on benefit-cost analysis and the economic management of public works (Ekelund and Hebert 1999).

Navier was not alone in having fundamental contributions spanning very different fields. Navier’s younger colleague Jules Dupuit is known today in groundwater and engineering for his contributions to flow modeling (which came from his work on sewers). But Dupuit’s more fundamental contribution was developing the idea of “consumer’s surplus” taught in every undergraduate economics class (1844). The famous economist and political philosopher Hayek, traces socialism to early French engineers. (Today’s modern engineering profession was developed orignally to serve the state, not the private sector.)

Talented engineers and physical scientists should not fear or disdain economics, policy, and social sciences. Many fundamentals in these fields were developed by the same folks who developed the fundamentals of engineering and physical and social science. As the early French engineers discovered, a broad range of fundamentals are important to combine for effective organized problem-solving.

There is ever a need to bring technical and social organization together for effective problem-solving. This is important for the professions, as well as governmental deliberations.

Further readings

Dupuit, Jules. “On the Measurement of the Utility of Public Works.” Translated by R. H. Barback from the Annales des Ponts et Chaussees, 2d ser., Vol. VII (1844) in the International Economic Papers, No. 2. London: Macmillan Co., 1952; reprinted in Kenneth J. Arrow and Tibor Scitovsky, eds., Readings in welfare economics, 1969.

Ekelund, R.B. Jr. and R.F. Hebert (1999), The Secret Origins of Modern Microeconomics – Dupuit and the Engineers, University of Chicago Press, Chicago, IL.

Hayek, F.A. (1944), The Road to Serfdom.

Langins, J. (2004), Conserving the Enlightenment: French Military Engineering from Vauban to the Revolution, MIT Press.

Navier, C-L (1832), “On the Execution of Public Works, Particularly Concessions,” ANNALES des PONTS ET CHAUSSÉES, N°. XXXV.1st Series, 1st Semester (1832) (translated poorly from the original French by Jay Lund): French original:

Navier, C-L Wikepedia article, English.

Navier, C-L Wikepedia article, French


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The long and winding road of salmon trucking in California

Spawning Chinook salmon at Nimbus Hatchery on the American River (image by Barry Lewis)

By Dr Anna Sturrock

Trucking juvenile hatchery salmon downstream is often used in the California Central Valley to reduce mortality during their perilous swim to the ocean. But is it all good? Researchers at UC Berkeley, UC Davis, UC San Francisco and NOAA Fisheries published an article in Fisheries this month exploring the history and implications of salmon trucking in a changing climate.

When I moved from England to California in 2012 to start a postdoctoral position at UC Santa Cruz, I distinctly remember the feeling of awe. Everything was on a bigger scale, and anything seemed possible. The patches of green English fields were replaced by never-ending rows of crops and fruit trees, gold-scorched hills, and craggy mountains. Our calmer, smaller waterways were replaced by fast-flowing rivers fed by dams the size of skyscrapers. Even the ocean waves were bigger here. When I started hearing about behemoth pumps that sucked so much water they reversed the river direction, and baby salmon hitching rides in trucks, I wasn’t sure if people were being serious. It turns out they were.

California is a land of plenty, boasting diverse, beautiful, vast landscapes and an abundance of natural resources. It also hosts a diverse and ambitious population of visionary thinkers with an unparalleled can-do attitude. Undeterred by its wildly variable Mediterranean climate of long, hot, dry summers and multi-year droughts, or wet, stormy winters that often flooded major towns, Californians have created a network of imaginative engineering solutions to store and move water around the state. One of the most transformative solutions to manage its boom-bust weather patterns was to build huge dams along the foothills of the Sierra Nevada to store winter rains and snow, providing water ‘banks’ to sustain domestic and agricultural users through the long, dry summers and droughts. These dams provide significant benefits to humans, supplying water to extensive agri-business and urban populations. However, the diversion of water, particularly during droughts, and the fragmentation of river habitats has drastically affected many aquatic species. For example, migratory fishes like Chinook (or King) salmon are often prevented from ascending the rivers to high elevation habitats where they would literally chill over the summer, eliminating the historically dominant spring run salmon from most Central Valley streams.

To mitigate for lost salmon production above the dams, five production hatcheries were built between 1944 and 1970 – Coleman National Fish Hatchery, and four state-operated hatcheries – Nimbus, Mokelumne, Feather, and Merced River Hatcheries. When I first moved here I wasn’t totally sure what hatcheries were: European media tends to focus on fish farms (where fish are kept in pens until they end up on your plate), generating horror stories about over-crowding, sea lice and escapees. So I was pleasantly surprised when I first visited a hatchery and talked to the people working there. I liken hatcheries to salmon IVF clinics (Fig. 1). Only these IVF clinics are not just addressing parent fertility issues, but providing luxury birthing suites, daycares and calorific dinners to the babies that would have otherwise been supported by the upstream habitat. Hatcheries then release the babies into the wild, typically once they have grown into smolts (‘fat toddlers’) to complete an otherwise natural life cycle.

The objectives of this study were to explore (a) when, where, and how many hatchery juveniles were released each year, (b) whether release patterns had changed through time, and (c) where these fish ended up if they were lucky enough to survive to adulthood.

Spawning Chinook salmon at Nimbus Hatchery on the American River (image by Barry Lewis)

In the early years (1940s to 1960s) everything was fairly low key compared with today – hatcheries tended to allow their youngsters to swim directly into the adjacent river where they would mingle with the wild fish, and they would swim to the ocean together (Fig. 2; also see our accompanying web app). In intermediate years (1960s to 1990s), the hatcheries intensified their role. For example, it was not a popular option to cull excess production (more babies than the hatchery could support), so – particularly in wet years – juveniles were often trucked to small, remote creeks that do not typically support their own salmon populations (e.g., Secret Ravine, Doty Ravine). Most of these fish were tiny and unmarked so we don’t really know what became of them – their offspring are probably an interesting study in themselves. However, over time managers and stakeholders got wise to the poor survival of juveniles during their perilous migration through the Sacramento-San Joaquin River Delta – historically, a diverse, mosaic of wetland habitats, now a channelized water conveyance system packed with introduced predators and contaminants. Thus, from 1980 onwards, trucking hatchery salmon directly to the ocean really took off, particularly during droughts. The argument is that chauffeuring fish past mortality hotspots (typically worse during droughts) gives them a survival advantage that boosts commercial and recreational fisheries. The idea of putting fish into a truck was a real culture shock for me. Faced with the same issues in the UK, I am pretty sure Boris Johnson would shrug his weary shoulders, mumble something incoherent, and we would all just have to tolerate low returns (of both hatchery and wild salmon) after droughts. Here, in historic drought year 2015, almost all the hatchery salmon produced (about 26.5 million individuals) were loaded into trucks and driven to the Delta, bays, or ocean (Fig. 2). That takes a lot of people, gas, and money. It also creates an even wider survival gap between hatchery and wild fish, contributing to the dominance of hatchery fish on nearly all Central Valley rivers.

Fig. 2 Densities (numbers) of hatchery salmon released during years characterized by (1) On-site releases (represented by each hatchery’s first release year); (2) non‐natal releases (spreading them out – e.g., in wet year 1998); or (3) trucking them to the bay (e.g., drought year 2015). ‘Bay’ indicated by a dashed line. Hatchery codes: COL = Coleman, FEA = Feather, NIM = Nimbus, MOK = Mokelumne, MER = Merced. Figure from Sturrock et al. (2019). If you want to download the release data or explore it in more depth, check out the accompanying web app.

Another consequence of trucking is that trucked salmon are much more likely to stray into other hatcheries or rivers when they return to spawn. Normally, young salmon create olfactory maps when they swim to the ocean, sequentially recording the smells they encounter along the way. If they are among the lucky few that survive to adulthood, they use these olfactory memories like street signs to find their way home. Trucked salmon have large gaps in their maps, making it harder for them to navigate home. We analyzed tagging data for salmon released by the five hatcheries since the start of the Constant Fractional Marking Program (an excellent program involving system-wide tagging of 25% of hatchery releases and increased tag recovery efforts to see who came back and where). We found that the further the salmon were trucked from the hatchery, the more likely they were to stray into a different river when they came back (Fig. 3). The effect was most extreme for hatcheries on smaller, more distant rivers, and when natal stream flows were lower during the period of return. We also found that fish returning at older ages were more likely to stray. These older individuals may simply be more forgetful, but it is more likely that their longer ocean residence time correlated with larger changes in the freshwater environment (i.e., their map became ‘outdated’), particularly in the Central Valley’s highly engineered waterways.

 Why do we care about straying? Some level of straying is natural and can help maintain genetic diversity, expand range boundaries, and recolonize impacted habitats. However, in a natural system, most individuals return home, allowing populations to adapt to local stream conditions (e.g., thinner individuals in shallower spawning grounds) and increase fitness (i.e., more babies per adult). The main concern is that excessive straying (often >80% of trucked juveniles strayed as adults) eliminates existing local adaptation, makes it harder for local adaptation to re-evolve, and can introduce maladapted genes into recipient populations. Excessive straying can also have more immediate impacts. For example, after Coleman (the biggest producer in the system) trucked all their fish to the Delta in 2015, so many of these fish strayed elsewhere when they returned in 2017 that Coleman was unable to meet its production goals (i.e., make enough babies for the next generation). Some argue that Central Valley salmon – being at the edge of the species distribution and more prone to drought and disturbances – might have higher baseline straying rates than their northerly counterparts. However, we found that the hatchery fish released on-site had “normal” straying rates, averaging 0.3% to 9.1% (i.e., if reducing straying rates were the only objective, then releasing on-site does seem to work).

Fig. 3 Observed (circles) and predicted (lines) straying indices of California Central Valley hatchery fish as a function of transport distance and return age (other model covariates averaged). Indices based on coded wire tag recoveries from brood years 2006–2012 (this study; circles) and 1980–1991 (Niemela 1996; crosses). Circles sized by the logged number of tag recoveries (used to weight model). Predicted straying rates for 3‐year‐old fish at minimum and maximum natal stream flows during the return period indicated by dashed lines (specifically, the range of mean October–November flows in return years 2008–2015, displayed above each plot). River distance from each hatchery to the bay indicated by an arrow (note, MER did not perform bay releases during the years examined). Hatchery codes defined in Fig. 2. Figure from Sturrock et al. (2019).

Hatcheries are often controversial and not everyone likes them. But without the Central Valley production hatcheries there would not be much of a salmon fishery in California, and – managed well – they could hold the key to salmon persistence in a rapidly changing climate. Trucking may help supplement the fishery in a given year, but it comes at a cost (impeding local adaptation and increased competition for food, mates, habitat – both from straying and the survival advantage provided by the trucking itself). Long-term, the combination of such high straying rates and such a large survival imbalance could reduce the stability of these populations and the fishery.

Fig. 4 Ranse Reynolds (retired CDFW Nimbus Hatchery Manager) at his home after interviewing him about some of the more vaguely described release locations.

Today, we are at an ecological tipping point, and California’s climate is predicted to become increasingly volatile and prone to hotter, longer droughts. To counter this uncertainty perhaps we should consider managing our fish and environment using a cautionary, risk-spreading approach that promotes long-term resilience, even if this occasionally leads to short-term losses in returns. Ideally, we would manage salmon stocks for both resilience and abundance, by (1) reducing straying rates of hatchery fish (e.g., using flow-through barges, segregation weirs, terminal fisheries, and attraction flows) and (2) enhancing the abundance and survival of natural-origin salmon (e.g., by increasing habitat carrying capacity via restoration and flow management). Many fish and water agencies, NGOs, stakeholder groups, and hatcheries are already exploring ways to achieve both objectives. Coleman and Mokelumne hatcheries have led the way in experimenting with alternative release strategies, and we are encouraged to see other hatcheries also trying broader release periods, and releasing fish closer to the hatchery in recent years. Such experiments may be expensive and challenging to perform, but – if carefully coordinated and repeated across water years – they will be crucial to informing management decisions in the future.

Central Valley Chinook salmon are at the edge of the species range and are clearly a tough breed – having already persisted in the face of multiple human impacts and extreme droughts. By trying new tools and working as a team – coordinating across watersheds, managers and stakeholder groups – we may be able to alleviate some of the issues we have created, and help these tough fish persist in a rapidly changing world.


This study built on the painstaking work carried out by Eric Huber transcribing decades worth of data from hatchery release reports into an electronic database. My first task was to add GPS coordinates to often incredibly vague site descriptions (e.g. “Misc.” or “Dry Creek” – do you know how many Dry Creeks there are in California?!). This involved a lot of interviewing (hassling) current and retired hatchery employees. I remember Anna Kastner digging out hand-drawn maps from the 70s from the Feather River Hatchery basement, Marc Provencher going through piles of physical planting receipts at Coleman, and Ranse Reynolds (retired Nimbus Hatchery manager – Fig. 4) and his wife Joyce, zooming around google maps from their home in Woodland while their grandkids played with my son. The historical insights were fascinating, and I was encouraged by how forthcoming and helpful everyone was. I cannot thank you enough. Thanks also to my dad, Barry Lewis, for the wonderful pictures of Nimbus Hatchery. Thanks also to Arnold Ammann, Walt Beer, Mark Clifford, Laurie Earley, Fred Feyrer, Brett Galyean, Ted Grantham, Scott Hamelberg, Tim Heyne, Paula Hoover, Rachel Johnson, Brett Kormos, Dave Krueger, William Lemley, Joe Merz, Carl Mesick, Cyril Michel, Kevin Niemela, David Noakes, Gary Novak, Bob Null, Mike O’Farrell, Kevin Offill, Jim Peterson, Corey Phillis, Rhonda Reed, Edward Rible, Paco Satterthwaite, Ole Shelton, Jim Smith, Ted Sommer, Bruce Sturrock, Lynn Takata, Mike Urkov, Judy Urrutia, Dan Webb, Peter Westley, Michelle Workman, and Steve Zeug for their comments, advice, support, and/or provision of data. Funding was provided by the CDFW Ecosystem Restoration Grant (E1283002), the Delta Science Fellowship Program (Award no. 2053) and CDFW Water Quality, Supply and Infrastructure Improvement Act of 2014 (CWC §79707[g]) (P1596028). I am also indebted to the massive efforts of all my coauthors – Stephanie Carlson, Will Satterthwaite, Kristina Cervantes‐Yoshida, Eric Huber, Hugh Sturrock, Sébastien Nusslé – and to my other mentor, Rachel Johnson, for giving me my first proper job, taking me to my first hatchery, and inspiring my obsession with salmon!

Anna Sturrock (@otolithgirl) is an Assistant Project Scientist at the Center for Watershed Sciences using natural and applied tags to reconstruct fish growth and habitat use. She is passionate about science communication and data visualization, and providing empirical data to support and inform natural resource management. Senior co-authors Drs Stephanie Carlson and Will Satterthwaite can also be found in the twittersphere as @fishteph and @satterwill.

Further reading

Sturrock, A. M., Satterthwaite, W. H., Cervantes-Yoshida, K. M., Huber, E. R., Sturrock, H. J. W., Nusslé, S., & Carlson, S. M. (2019). Eight Decades of Hatchery Salmon Releases in the California Central Valley: Factors Influencing Straying and Resilience. Fisheries, doi:10.1002/fsh.10267 (linked here)

Web app to visualize the release data across time and space:

Huber, E. R., & Carlson, S. M. (2015). Temporal trends in hatchery releases of fall-run Chinook salmon in California’s Central Valley. San Francisco Estuary and Watershed Science, 13(2) (linked here)

Niemela (1996) – Effects of release location on contribution to the ocean fishery, contribution to hatchery, and straying for brood years 1987-1991 fall Chinook salmon propagated at Coleman National Fish Hatchery. USFWS. Northern Central Valley Fish and Wildlife Office, Red Bluff (linked here)

California Hatchery Scientific Review Group (2012). California Hatchery Review Report. Prepared for the USFWS and PSMFC (linked here)

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Providing Flows for Fish


Putah Creek below Putah Creek Diversion Dam, December, 2014, a drought year.  The stream flows are regulated in part to support a diverse native fish fauna, including Chinook salmon.

by Peter Moyle

A reality in California and the American West is that people are competing with fish for water. We humans are winning the competition.  However, because there are moral, aesthetic, and legal obligations to provide fish with water in streams, biologists like me often get asked the question “Just how much water do the fish need, anyway?” This, of course, is the wrong question because the best reply is  “all of it!” if you consider the stream flows under which each fish species evolved, that often varied from raging torrents to gentle summer trickles across a single year.   The question may then switch to, “well, what is the minimum flow we need to provide to keep the fish alive?”  This is also the wrong question because if you keep a stream fish assemblage on minimum flows for a long enough period, most native species will likely disappear. In their place will be trout raised in hatcheries and non-native species like fathead minnows and green sunfish; these fish will live in a highly degraded habitats, signified by dead riparian trees and stagnant pools. A more useful question is “what is the optimal flow regime that will allow a diverse native fish fauna and other biota to thrive, while providing water for use by people?”

Attempts to find an answer to the last question, usually by simple, cheap hydrologic methods, have dominated stream flow disputes over fish for decades.  While some regions now typically use holistic approaches, in the USA and few other countries there remains heavy reliance on mechanistic approaches such as the Instream Flow Incremental Methodology (IFIM) and its modeling companion PHABSIM.  Frankly, these methods don’t work very well, because they are based on some untenable assumptions and on simplified models that bear little resemblance to ecological reality. Without trying to explain them further, lets just say they are likely to work best in a ditch that contains only rainbow trout.  So what does work for most streams?  There are several good options, which are explained in a new book Environmental Flow Assessment : Methods and Applications by John Williams,  Peter Moyle, Angus Webb, and Mathias Kondolf (2019, Wiley Blackwell, 220 pages).  You will note that I am a co-author so you may want to read this summary with some skepticism.


It is not by accident that the two chapters of the book following the introductory chapters are primers on flow and life in rivers and streams.   These chapters make the point that flowing waters are beautifully complex both physically and biologically, so it is rather naïve to think that a simple hydrologic model will suffice to determine flows needs for desirable aquatic life  (or even just fish).

The next chapter (5) deals with tools for environmental flow assessment (EFA). It shows that we don’t have to be content with standard hydrologic models because there are so many options these days, of intellectual tools, models, concepts and approaches that be used for EFA. Examples of new approaches to EFA that the book describes include Bayesian networks and hierarchical Bayesian models, of growing interest in biological systems.  Of course, tools are only as useful as the users make them.  “Ultimately, successful EFA depends on clear and critical thinking; the human brain is the most important tool for environmental flow assessment (p. 51).”

Once the myriad of tools available for EFA are in hand, there are many options for methods to determine environmental flows. Chapter 6 classifies these options and provides a critique of how and when each one is useful; the methods range from very simple to very complex. Any of them can be misused, of course, but most methods, preferably holistic ones, can be adapted to local situations.  The latter is important because no two streams are exactly alike so when a study is proposed, diverse options should be considered.

This is also true for the use of models in flow assessment, which seem ubiquitous. They are often used as if they can, by themselves, provide definitive solutions to a flow problem.   Because of this, the book (Chapter 7) provides a lengthy discussion on modeling and model testing.  It‘s the kind of background we hope everyone involved in an EFA relies on from the beginning. But the most basic lesson here is that: “Models are best used in EFA to help people think, not to provide answers (p. 141).”

Nowhere in the EFA universe are models more important than when looking at the how rivers are regulated below dams. Indeed, most EFAs are done on regulated streams.  Historically, most EFAs were couched as water vs fish, with little attention paid to inevitable geomorphic simplification of fish habitat that dams cause. Dams reduce sediment inputs, stabilize stream channels, and eliminate most high flows events. These processes are important for allowing stream channels to support diverse riparian and aquatic habitats for fish and all other aquatic life (Chapter 8).  Maintaining a ‘living stream’ below a dam is hugely challenging, but possible if an adaptive attitude is maintained towards EFMs.

Much of the book is critical of common methods for EFA. However, Chapter 9 presents a highly workable approach for the typical case where limited data are available, so expert opinion becomes more important for developing a flow regime that favors desirable species, usually fish.  The trick is to use structured methods to turn expert opinions (including those from published papers and reports) into a conceptual model of the situation. The conceptual model can then be quantified as a Bayesian Network Model. This model can be continuously improved as more data becomes available.  Ideally these data would be collected from the stream being modeled, by monitoring the effects of an initial flow regime. This results in a ‘feed back loop’ of more data making the model more useful followed by further manipulation of the study stream.  Eventually, the greatly improved data set will allow a more powerful Bayesian hierarchical model to be used.

The final chapter is short but contains the statement  “We have also emphasized that EFA is human activity and so subject to human behavior.”   This idea should be kept mind even when evaluating abstract hydrologic models. The book ends with a long checklist of things to keep in mind when conducting an EFA.

Because the book is aimed a broader audience than the people who just conduct EFAs, we made an effort to keep the language as concise, jargon–free and as clear as possible, given our own deep interests in the issues. In fact, clear writing is key to good EFAs, especially plain-word summaries of technical reports.

It is hard to over-emphasize the need for improved and innovative assessments of environmental flows in California’s streams, because there are over 1400 large dams in the state. Most dams need periodic reassessment of their flows for aquatic life, especially fish.  Climate change, with longer droughts and bigger floods, will create more disputes over managing the limited water supply. Improved understanding of the EFA options available should make settling such disputes in an amicable fashion more likely.

Further reading

Williams,  J., P. Moyle, A. Webb, and M. Kondolf (2019), Environmental Flow Assessment : Methods and Applications (Wiley Blackwell, 220 pages).




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The Good, the Bad, and the Ugly of California’s State-Mandated Urban Water Conservation during Drought

Drought face 1by Amy Talbot

Amy Talbot is the Regional Water Efficiency Manger for the Regional Water Authority, which represents 21 water suppliers in the Sacramento region.  She manages an award-winning public outreach and education program.  Additionally, she is a board member of the California Water Efficiency Partnership (CalWEP), which is supporting water suppliers with the implementation of Senate Bill 606 and Assembly Bill 1668. This blog post is based on her MA thesis, both of which solely represent her personal opinions and may not be attributed to the Regional Water Authority or its member water suppliers or the California Water Efficiency Partnership or its members.

Historic 2014 weather and water supply conditions prompted Governor Brown to order the state’s first mandated conservation targets for over 400 urban retail water suppliers starting in 2015.[1]  Governor Brown tasked the State Water Resources Control Board (SWB) and the California Department of Water Resources (DWR) to manage and enforce these mandates.  With a 25% statewide water use reduction goal, state agencies, water suppliers, media, businesses, and residents worked together to implement supply and demand side actions to limit water use.  The state met this goal, reducing urban use by 24.5% from June 2015 through May 2016 equating to 524 billion gallons (1.6 million acre-feet) compared to 2013 water use.[2]  The state’s drought response was seen by some as an overwhelming success and by others as an unprecedented, and possibly illegal, invasion of local water suppliers’ management of their water supplies, water systems and relationships with their customers.  Regardless of perspective, it was uncharted territory, with new policies introduced in a short time with varying benefits and some unexpected consequences.  Through analyzing the practical outcomes of the state’s drought response, the overall experience can be distilled into what worked and what didn’t.

What Worked:

  • Prioritizing outdoor water use conservation over indoor conservation: Public outreach messaging focused on outdoor water use, which can be reduced quickly, with significant savings in most areas, while protecting indoor uses that support public health and safety.
  • Consistent water supplier reporting: Monthly reporting by water suppliers to the state allowed for real time monitoring to assess current water demand conditions and provided public transparency on water use.
  • Greater drought awareness: The state, the media, businesses, and residents maintained widespread attention on the drought, which prolonged water savings.
  • Water supplier coordination: Water suppliers found commonality through shared conservation targets and kindred feedback to the state on proposed regulations. Furthermore suppliers shared, exchanged, and coordinated public outreach campaigns and programs to more effectively respond to drought.

What Didn’t Work:

  • Conservation targets neglected water supply adequacy: Mandated water use based conservation targets did not directly respond to local water supply shortages.
  • Lack of optimization of alternative supplies and markets: The state’s drought response approach did not substantially consider local water suppliers’ prior investments in drought-resistant supplies and planned drought responses and therefore, at times, reduced local suppliers’ ability to respond with non-conservation water supply actions during drought, such as short-term or long-term water purchases, use of groundwater in storage, etc.
  • Ineffective communication: Communication breakdowns during the drought between state agencies, water suppliers, and customers complicated public outreach messaging aimed at reducing water use. One example is the use of the U.S. Drought Monitor to convey state and local water supply and drought conditions.
  • No regional compliance option: The initial rejection of a regional compliance option to meet state conservation mandates reduced incentives for local agencies to collaborate regionally.

Near the end of the mandated conservation target period, Governor Brown issued an Executive Order (EO) titled “Making Water Conservation A California Way of Life.”  Several concepts in the EO were incorporated into Senate Bill (SB) 606 and Assembly Bill (AB) 1668, which were passed in May 2018.  These bills will establish new local water supplier water efficiency targets based on indoor and outdoor residential water use, commercial, industrial, and institutional landscape water use, and water lost through leaks.  The bills will also increase supplier drought planning efforts through an expanded 5-year drought planning timeframe and statewide standard stages and percent reductions for urban water suppliers’ water shortage contingency plans.

Over the next decade, the state, urban water suppliers, businesses, and residents will implement this legislation, effectively redefining water efficiency and drought management planning in California.  The stakes are high with pending financial, staffing, policy, and infrastructure impacts for retail urban water suppliers and tight timelines for the state to finalize regulations before suppliers begin reporting in 2023.  Below are some recommendations for the successful implementation of SB 606 and AB 1668 and improved drought response in California.

Recommendations for Senate Bill 606 and Assembly Bill 1668 Implementation:

  • The state should clarify its statewide water saving goal and objectives: SB 1668 states that the water savings from the new regulation “would exceed the statewide conservation targets required”, meaning it would exceed the target of a statewide 20% reduction in urban use by 2020 established by 2009’s Senate Bill X7-7.  However, not all water suppliers under the current statewide conservation targets are required to save exactly 20% – targets vary up to 20% depending on several factors. Is the new savings goal to exceed targets at the statewide level or by each individual supplier?  What is the baseline used to calculate this new savings?
  • Outdoor water use reductions should be moderate: The state heavily focused on reducing outdoor watering during the recent drought. While widely accepted in a drought emergency, continuously reducing landscape water use beyond levels of efficiency can harm other landscape functions like providing habitat, healthy soil, quality of life benefits, tree health, and stormwater management.
  • State driven water efficiency efforts should match expected savings: Is the “juice worth the squeeze” for these regulations?  The resource commitment (staff and funding) needed to implement complex local supplier water budget targets should not exceed potential benefits from the anticipated water savings.
  • Energy efficiency funding should supplement water efficiency program budgets: As shown during the drought, water savings also produced energy savings, sometimes more cost-effectively than standard energy efficiency programs (Spang et al., 2018). Local water and energy suppliers should continue to work together towards mutual resource savings goals.
  • The state should allow a compliance target range for urban water suppliers: With many data-based details and potential for error in the designing and implementing of these new regulations, the state should allow flexibility in enforcement of the urban water supplier targets.

Recommendations to Improve Drought Response:

  • Drought water use reductions should be linked to local water supply conditions: Drought is ultimately a local condition and water suppliers respond to the risk of it by investing in water supplies and other measures that are available locally. Perhaps the biggest misstep from the 2014-2016 drought was the initial state-mandated conservation targets based on water use, not water supply.
  • Residential lawns should be water conservation reserves in future droughts: Collectively, lawns throughout a water supplier’s service area could be tapped to reduce residential water demand rapidly by up to 50% in some areas of the state. No other single action can deliver this reduction short of cutting off service or risking public health.
  • Urban water suppliers should have approved drought revenue recovery mechanisms compliant with Proposition 218 as part of their standing policies and rate structure: Water suppliers should not be required by the state or any other entity to trigger this mechanism, but a revenue recovery option should be readily available to suppliers in the event of supply interruptions due to drought or other reasons. 
  • Drought management should be controlled locally, coordinated regionally, and overseen at a state level: State and regional actions should not disrupt suppliers from investing in reliability planning; instead, the state should recognize the local, regional, and statewide benefits of reliability investments. Local water suppliers should maintain their own policies and drought response plans.
  • Local, regional, and state entities should work more closely with media outlets to accurately report water related information: Staff at all three levels should have media training, updated communication plans, and media talking points/messaging available to facilitate ongoing relationships with local media.  Water savings during drought largely depends on customer actions (or inactions) supported and communicated by statewide, regional, and local media reporting, local water suppliers, and other public outreach efforts.
  • Rebate programs should be less prominent during drought: Generally, rebate programs create limited direct water savings during droughts, but expend significant staff time and funding. During drought, water suppliers should prioritize broader public and media outreach focused on reducing outdoor water use.

The SB 606 and AB 1668 recommendations would increase the prominence of water efficiency in the state and nudge it closer to where it belongs, towards deeper, and in some cases equal integration with other resource management actions like supply augmentation.  The days of conservation and efficiency programs being thought of as “stickers and bubblegum” are behind us.  In the absence of implementing these recommendations, SB 606 and AB 1668 could be implemented in ways that deter improving overall efficiency through superfluous and ineffective requirements that become more of a burden than a valuable investment.  The drought response recommendations seek to smooth over some of the harsher edges experienced in the last drought and improve response to the next drought.

In the meantime, debates over how to manage water in California will continue at all levels.  The state and water suppliers will keep trying, working toward their own solutions in coordination with others.  It is a give and take, a push and pull, even a power struggle at times that shapes and advances water efficiency within overall water management.  It’s both frustrating and fascinating.  It could not be any other way.

Final Thought:

“Unfortunately, we tend to focus on drought when it is upon us. We’re then forced to react — to respond to immediate needs, to provide what are often more costly remedies, and to attempt to balance competing interests in a charged atmosphere. That’s not good policy. It’s not good resource management. And it certainly adds to the public’s perception that government is not doing its job when it simply reacts when crises strike. To the contrary, we must take a proactive approach to dealing with drought. We must anticipate the inevitable — that drought will come and go — and take an approach that seeks to minimize the effects of drought when it inevitably occurs.” — James R. Lyons, Assistant Secretary of Agriculture for Natural Resources and the Environment, speaking at Drought Management in a Changing West: New Directions for Water Policy, in Portland, Oregon, in May 1994.

Drought face 2
Further Reading and Resources

Talbot, Amy.  (March 2019).  “Urban Water Conservation in the Sacramento, California Region during the 2014-2016 Drought.”  Master thesis in Geography, University of California, Davis.

State of California.  (April 2017). “Making Water Conservation a California Way of Life: Implementing Executive Order B-37-16.”  Final Report.

Brown, Edmund G. (May 2016).  “Executive Order B-37-16: Making Water Conservation A California Way Of Life.”

State of California. (2018). “Making Water Conservation a California Way of Life: Primer of 2018 Legislation on Water Conservation and Drought Planning Senate Bill 606 (Hertzberg) and Assembly Bill 1668 (Friedman).”

California Department of Water Resources (DWR). (2019). “Making Conservation A Way of Life.”  Webpage.

Mitchell, David, Hanak, Ellen, Baerenklau, Ken, Escriva-Bou, Alvar, Mccann, Henry, Perez-Urdiales, Maria, & Schwabe, Kurt. (2017).  “Building Drought Resilience in California’s cities and suburbs.” Public Policy Institute of California (PPIC).

California Department of Water Resources (DWR). (May 1978).  The 1976-1977 California Drought: A Review.

California Water Efficiency Partnership (CalWEP). (2019). “Framework Compliance.” Webpage.

Spang, Edward S., Holguin, Andrew J., and Loge, Frank J.  (January 12, 2018). “The estimated impact of California’s urban water conservation mandate on electricity consumption and greenhouse has emissions.” Environmental Research Letters, Volume 13, Number 1.

Feinstein, Laura, Phurisamban, Rapichan, Ford, Amanda, Ford, Christine, and Crawford, Ayana. (January 9, 2017). “Drought and Equity in California.” Pacific Institute.

Seapy, Briana. (March 2015).  “Turf Removal & Replacement: Lessons Learned.” California Urban Water Conservation Council.

End Notes

[1] “Urban retail water suppliers” are either public or private owned, providing water for municipal purposes directly or indirectly to more than 3,000 customers or supplying more than 3,000 acre-feet of water annually.  (California Water Code Section 10617).

[2] June 2015-May 2016 represents the timeframe for the state’s mandatory conservation targets for urban retail water suppliers.  Source: State Water Resources Control Board (SWRCB). (July 6, 2016). “Emergency Water Conservation Regulation Update-Office of Research, Planning, and Performance.”  Staff Presentation.


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Who governs California’s drinking water systems?

By Kristin Dobbin and Amanda Fencl

A key feature of California’s drinking water system is the large number of individual water systems. There are approximately 3,000 Community Water Systems (CWSs) in the state, meaning systems that serve a residential population year-round (the remaining 5,000 of the state’s 8,000 Public Water Systems are non-community systems serve places like schools, daycare, hospitals, campgrounds, or businesses that serve at least 25 people but have transient or non-residential populations. Additionally there are an unknown number of unregulated water systems in the state that do not meet the 25 person or 15 connection size threshold for regulation under the Safe Drinking Water Act. This extreme decentralization and fragmentation of governance results from local land use decisions, politics and a preference for local control by the state and locals. While allowing for local control and flexibility, this arrangement has not guaranteed safe drinking water for all (NYT 2019; Politifact 2019; SacBee 2018). More than a million Californians lack safe water, primarily in low-income communities, communities of color, indigenous communities and rural communities.

Particularly for CWSs, governance is critical to resolving the crisis (Wutich et al. 2016; Newig and Fritsch 2009). The number of systems and diversity of structures under which they operate, however, is a challenge for policy and practice. For system consolidations, for example, solutions need to be developed and implemented with explicit consideration for how system governance affects representation and accountability (Nylen, Pannu, & Kiparsky 2018). And in newly formed Groundwater Sustainability Agencies, disadvantaged communities without CWSs that are public agencies (e.g., mutual water companies) are significantly less likely to be represented as decision-makers (Dobbin and Lubell 2019). Better understanding the existing landscape of CWSs in California is key to understanding how governance can address the entrenched disparities.

An important first step in this direction is to identify and analyze the range of CWS governance arrangements. To do so, we coded each of the 2,895 active CWSs in the state as of the end of 2018. Where possible, we relied on standardized names reflecting specific public district types (e.g. Community Services Districts, County Service Areas), and where not, we employed Consumer Confidence Reports, websites, tax filings and general Google searches using the system’s name and location to identify its specific organization types such as Mutual Water Companies or Property Associations. We also cross-referenced our data with existing lists such as the Public Utility Commission’s list of Investor-Owned Water Utilities. Ultimately, we identified 26 distinct system types as defined by a system’s legal structure/derived authority, who operates it and/or who it serves. These 26 types are aggregated into nine governance categories and classified as either publicly or privately owned entities. The table below summarizes these findings.

Table 1. Breakdown of California’s Community Water Systems by governance category and type

  # of CWSs Median population served # of
CWSs w/ violations
Average # violations per CWS*
All CWSs  (PWS with > 15 connections or 25 people) 2,895 287 854 2.27
Publicly Owned CWSs 1,166 2,984 295 1.92
City: City (315); Special Act District (2) 317 22,795 80 1.43
County Service Area (77); Maintenance District (46); County Waterworks District (27); County Sheriff (12); County Dept. (excluding sheriff) (11); Special Act District (8);
Resort Improvement District (2)
183 350 55 3.08
Joint Powers Authority 12 109,254 0
Independent Special Districts:
Community Services District (185); County Water District (165); Public Utility District (53); Irrigation District (51); Special Act District (34); California Water District (32); Municipal Water District (31); Sanitary District (6); Municipal Utility District (3); Water Conservation District (3); Resort Improvement District (2); Resource Conservation District (1)
566 1,885 132 1.8
State and Federal: Federal (38); State (50) 88 2,200 28 2.36
Privately Owned CWSs 1729 126 559 2.51
Investor Owned Utility 220 1,695 39 1.49
Mobile Home Parks 375 108 124 2.3
User Owned Utilities

Mutual Water Company (582);
Property / Homeowners Associations (70)

652 124 218 2.34
Other private systems 482 79 178 3.36
*SDWA violation data was calculated by combining two data sources. The first is 2012- 2018 documented health-based violations from the State Board’s Human Right to Water portal, which excludes total coliform violations (SWRCB 2018). Because of this exclusion, we added Total Coliform Rule (TCR) health-based violations for each system from the SDWIS federal reports database (EPA 2019). When combined, the total number of CWSs with > 1 violation jumps from 525 to 854. The average number of violations per system in the last column is the average across all systems in each governance category.

From this analysis, four findings stand out:

1. There is considerable diversity in governance structures among CWSs, with greater diversity for public and small systems. As previously mentioned, we identified 26 distinct governance types among the 2,895 CWSs. Public CWSs make up 21 of these types, including 12 distinct types of independent special districts. Two types, Special Act Districts and Resort Improvement Districts appear in multiple governance categories because their enabling legislation set forth different options for composing their governing boards. The most frequent types of public systems are cities (315), Community Services Districts (185), and County Water Districts (165). There are five types of privately owned CWSs, including a catch-all category for “other private” systems representing for-profit, not-investor owned systems that we were unable to further disaggregate. Mutual Water Companies are the most common type of private CWS (582), followed by “other privates” (482), and mobile home parks (375). Using the median population served to classify each type as being comprised of either predominantly small (< 10,000 people served) or large ( > 10,000 people served) systems. Five types are predominantly large systems: Water Conservation Districts, Joint Powers Authorities, Resource Conservation Districts, Municipal Water Districts and Cities. The remaining twenty-one types are predominantly small systems.

Fig 1


2. System ownership and size are inversely related. While Most Californians (95%) get their water from 475 systems that are large (30%) or very large (65%), most (84%, 2,420) of California’s CWS serve less than 10,000 people. These smaller systems are responsible for drinking water provision to approximately 2.3 million people. 68% of such systems are privately owned (n=1,644), compared to just 18% of larger systems (n= 82).

Fig 2


3. Overall, around one-third of systems in the state have had a health-based violation in the last 7 years, but these incidents are not evenly spread across all governance categories. California’s CWSs have an average of 2.27 violations per system between 2012 and 2018. More information, however, can be gained by summarizing violations by governance category as we do in the table above. Excluding Joint Powers Agreements, where all twelve systems had zero violations, cities have the lowest average, just 1.43 violations per system over the seven years. In comparison, “other private” systems had an average of 3.36 violations followed by county operated systems with an average of 3.08 per system.

4. Health-based violations incidents are also not evenly spread across all system sizes in the last 7 years. As other studies have consistently shown, smaller systems have a harder time delivering safe water. Small and very small systems account 76% of all CWSs and 88% of the total violations in the data. Looking just at the 1,732 very small systems serving less than 500 people, five governance categories, on average, all have more violations than the statewide average: County (4.03), “other private” (3.6), Investor Owned Utilities (2.54), User Owned Utilities (2.51), and Mobile Home Parks (2.35).

Kristin Dobbin is a PhD student in Ecology at UC Davis studying regional water management and drinking water disparities in California. Amanda Fencl recently completed her PhD in Geography at UC Davis and is now a Postdoctoral Research Associate at Texas A&M University.

Further Reading

Nylen, Pannu & Kiparsky (2018). Learning from California’s Experience with Small Water System Consolidations: A workshop synthesis. Center for Law, Energy and the Environment, UC Berkeley.

McFarlane, K., & Harris, L. M. (2018). Small systems, big challenges: review of small drinking water system governance. Environmental Reviews, 26(4), 378-395. DOI: 10.1139/er-2018-0033.

Teodoro, M. (2019). Grow to Shrink, Shrink to Grow. June 27, 2019.

London et al. (2018)  The Struggle for Water Justice: Disadvantaged Unincorporated Communities in California’s San Joaquin Valley.  Center for Regional Change, UC Davis.

Pannu (2012) Drinking Water and Exclusion: A Case Study from California’s Central Valley. 100 Calif. L. Rev. 223.

Ekstrom et al. (2018)  Drought Management and Climate Adaptation of Small, Self-Sufficient Drinking Water Systems in California. California’s Fourth Climate Change Assessment, California Natural Resources Agency. Publication No. CCCA4-CNRA-2018-004.

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