Remarkable Suisun Marsh: a bright spot for fish in the San Francisco Estuary

Picture 1 suisun blog

by Teejay O’Rear and Peter Moyle

To most people, Suisun Marsh is either the seemingly blank area visible at 70 MPH from the north side of Highway 680 or the sudden expanse of tules visible after the Amtrak train leaves Suisun City, headed for Oakland. However, it is one of our favorite places in California, where it is easy to imagine being in a different place and time, with sturgeon jumping out of the water; flocks of ducks, ibis, and pelicans flying overhead; otters swimming by; and tule elk coming down to the water’s edge for a drink.  We know the marsh well because we have been taking a boat out every month to sample its fishes.  This sampling started 40 years ago, when Peter Moyle and a graduate student, Don Baltz, did some trawling in the marsh to look for tule perch and learned it supported many fish of all sorts.  Here we provide an updated account of Suisun Marsh fishes to show why the marsh is so important for conserving fishes in the upper San Francisco Estuary in general…and why we continue to be enthusiastic about working there.

Suisun Marsh is a brackish-water marsh bordering the northern edges of Suisun, Grizzly, and Honker bays in the San Francisco Estuary; it is the largest uninterrupted estuarine marsh remaining on the western coast of the contiguous United States. Much of the marsh area is diked wetlands managed for waterfowl, with the rest consisting of tidal sloughs, marsh plains, and grasslands. The marsh’s central location in the northern San Francisco Estuary makes it an important habitat for diverse freshwater, estuarine, and marine fishes.  The marsh also is a migratory corridor for anadromous fishes such as Chinook salmon and striped bass.

Pic 2 suisun

Suisun Marsh (map by Amber Manfree).

The protection of Suisun Marsh was specifically written into the bill creating the State Water Project, mainly to ensure that waterfowl populations would not be harmed by increased diversions of fresh water.  Fish were also part of that protection, so in January 1980, the Department of Water Resources contracted with UC Davis to monitor fish populations in the marsh. The result was our Suisun Marsh Fish Study, which has consistently used beach seines and otter trawls to sample juveniles and adults of all species since the study’s inception.  The primary objectives of our study have included (1) evaluating effects on fishes of the Suisun Marsh Salinity Control Gates, which began operating in 1988; (2) examining long-term changes in Suisun Marsh’s ecosystem relative to other changes in the San Francisco Estuary; and (3) enhancing understanding of the life history and ecology of key species in the marsh.  Secondary objectives have included supporting research by other investigators through special collections; providing background information for in-depth studies of other aspects of the Suisun Marsh aquatic ecosystem, such as the feeding ecology of jellyfish; serving as a baseline for restoration projects; contributing to the general understanding of estuaries through publication of peer-reviewed papers; training undergraduate and graduate students in estuarine studies and fish sampling; and providing a way for managers, biologists, and anyone else interested in the marsh to experience it firsthand.

Pic 3 suisunThirty-nine years of annual otter trawl catches of the Suisun Marsh Fish Study, with key events noted. Note that catches of native and non-native fishes generally follow similar trends.

Our study has documented many patterns in the ecology of the fishes in both space and time. Moyle et al. (1986) evaluated the first five years of data and found three groups of fish species: one that was generally most abundant early in the calendar year (including small staghorn sculpin and starry flounder); another that was common in cool months (including threadfin shad, Delta smelt, and longfin smelt); and a third that was always present in the marsh, comprised of many species but dominated by Sacramento splittail, striped bass, and tule perch.  The species composition of the fish assemblage was relatively constant across years.  Native fishes were more prevalent in small, shallow sloughs, while non-native species were more prominent in large sloughs.

Total fish abundance declined across years because extremely favorable spawning and rearing conditions early in the study period were followed by both a drought and a major flood that resulted in poor recruitment (see figure).

Meng et al. (1994) incorporated eight more years into their analysis, which revealed that the composition of the fish assemblage was less constant over the longer period than the earlier study indicated. In addition, non-native fishes had become more common in small, shallow sloughs. This study also found a general decline in total fish abundance through time. The decreasing fish numbers appeared to be related to (1) drought and high salinities harming both native and non-native fishes, (2) effects of new invasions (e.g., overbite clam), and (3) increases in water diversions.

Eight years later, Matern et al. (2002) found results similar to Meng et al. (1994): fish diversity was highest in small sloughs, and fish abundances had fallen further.  However, since then, fish catches have often been higher, particularly in wet years. Notably, some fishes that have become scarce in the estuary’s main rivers and bays since the early 2000s have either increased (e.g., Sacramento splittail) or remained abundant (e.g., small striped bass) in Suisun Marsh.

While analyzing data collected in 2018, we noted the following trends in some key species:

Delta smelt.  For the third consecutive year, we caught no Delta smelt, providing further evidence that this species is approaching extinction in the wild.

Longfin smelt.  Numbers of this smelt remained very low, but a few were caught almost every month.

Threadfin shad.  This non-native shad is one of the most abundant plankton-feeding fish in the marsh with numbers that fluctuate greatly from year to year. Numbers seem to be gradually increasing from its lows in 1989-1995, with a peak in 2017.  Numbers in 2018 were considerably less than in 2017, but still in the top five years.

American shad.  Since 2001, the number of juvenile American shad, a non-native anadromous species, has gradually increased, roughly following abundance trends of threadfin shad, including record numbers caught in 2017.  This suggests that the two shad species are generally being affected by the same factors.

Striped bass juveniles are also non-native plankton feeders and are typically the most abundant fish in our trawl catches. They also had a peak in 2017, with a drop in 2018 to more typical numbers. However, the long-term trend in catch since 1980 is mildly downwards, with lots of erratic rises and falls from year to year.

Sacramento splittail is a native fish that spawns on floodplains upstream of the marsh but spends most of its time in the marsh feeding on invertebrates.  After a severe decline from 1980 to 1994, its numbers have steadily increased, with 2018 being the peak year for abundance.  We suspect that its continued increase through wet and dry years results from restoration actions on the Yolo Bypass and Cosumnes River floodplains coupled with favorable conditions in the marsh.


Sacramento splittail are native fish uncommon outside of Suisun Marsh, except when they leave to migrate upstream to spawn on floodplains. Photo by Teejay O’Rear

White catfish, a non-native, almost disappeared from Suisun Marsh during the 2012-2016 drought, because high salinities and low flows inhibited reproduction. High flows in 2017 did not replenish the population, so catches remained low in 2017 and 2018.

Mississippi silverside is an abundant non-native species that probably invaded the marsh just a few years before our study began. It hugs the edges of sloughs during the day and feeds on small invertebrates and larval fish. Numbers increased steadily to 2006 and then dropped to consistent, moderate levels.

Overall, 2018 was a modest year for native and other important fishes. After achieving very high numbers in the wet year of 2017 (see figure), fish abundances returned to more typical levels in 2018.  Non-native fishes dependent on plankton for part of their life cycle (American shad, threadfin shad, striped bass) declined from 2017 to 2018, but they were still relatively abundant in Suisun Marsh in contrast to the bays and large rivers of the estuary. However, native smelts were virtually absent in both Suisun Marsh and the main bays/rivers. The negligible smelt numbers and lower numbers of some other native fishes after 2017 (threespine stickleback, prickly sculpin) in Suisun Marsh were contrasted by the highest-ever abundance of Sacramento splittail.

In sum, the catches in 2018 highlighted:

  • the importance of flows and related salinities on fish abundance in Suisun Marsh, with higher flows generally yielding more fish, both native and non-native;
  • the disproportionate importance of Suisun Marsh for warm-water planktivorous fishes, especially striped bass juveniles;
  • the importance of the marsh as a nursery area for many species; and
  • the importance of Suisun Marsh as the estuary’s bastion for Sacramento splittail.

We continue to be fascinated by the dynamic nature of Suisun Marsh and the abundance of life it supports.  We also are improving our understanding of how diverse environmental factors, from droughts to operation of water projects, affect the marsh’s fishes. Our 40 years of study are likely to be especially useful in determining – and predicting – the effects of global climate change on the estuary and its fishes.

For more complete information see O’Rear et al. (2019). For an overview of Suisun Marsh, see Moyle et al. 2014.

Teejay O’Rear is a fish ecologist at the Center for Watershed Sciences. Peter B. Moyle is a UC Davis Professor Emeritus of fish biology and an associate director of the Center for Watershed Sciences.

Further reading

California Department of Fish and Wildlife. 2019. Trends in abundance of selected species. Available: (March 2019).

Matern, S. A., P. B. Moyle, and L. C. Pierce. 2002. Native and alien fishes in a California estuarine marsh: twenty-one years of changing assemblages. Transactions of the American Fisheries Society 131: 797-816.

Meng, L., P. B. Moyle, and B. Herbold. 1994. Changes in abundance and distribution of native and alien fishes of Suisun Marsh. Transactions of the American Fisheries Society 123: 498-507.

Moyle, P. B., R. A. Daniels, B. Herbold, and D. M. Baltz. 1986. Patterns in distribution and abundance of a noncoevolved assemblage of estuarine fishes in California. U. S. National Marine Fisheries Service Fishery Bulletin 84(1): 105-117.

Moyle, P. B., A. D. Manfree, and P. L. Fielder. 2014. Suisun Marsh: ecological history and possible futures. Oakland: University of California Press.

O’Rear, T. A., P. B. Moyle, and J. R. Durand. 2019. Suisun Marsh Fish Study: trends in fish and invertebrate populations of Suisun Marsh January 2017 – December 2017. California, California Department of Water Resources.  Available at:

Editorial note: appears to have surpassed 12,000 followers.  Thanks to the blog’s many contributors, readers, forwarders, editors, reviewers, commenters, and discussers who have made the blog useful and/or entertaining over the years.  We always encourage thought-provoking readable pieces that have at least a tinge of scholarly insight for real people involved in California’s diverse and complex water problems.

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Can Water Agencies Work Together Sustainably? – Lessons from Metropolitan Planning

by Jay Lundmpo-map.jpg

It is said that, “In the US, we hate government so much that we have thousands of them.”  This decentralization has advantages, but poses problems for integration.

Integration is easy to say, and hard to do.  Integration is especially hard, and unavoidably imperfect, for organizing common functions across different agencies with different missions and governing authorities.  (Similar problems exist for organizing common functions across programs within a single agency.)

Much of what is called for in California water requires greater devotion of leadership, resources, and organization to multi-agency efforts.  Some identified needs include:

  • A common state water accounting framework to support groundwater management, environmental flows, water rights, water markets, and a range of voluntary agreements (Escriva-Bou et al. 2016; Bruun 2017).
  • Common frameworks to harmonize regulations across agencies to better achieve societal objectives (Gray et al. 2013).
  • Cross-agency science programs to give a common foundation for policy discussions, management, negotiations, and agreements (DSP 2019).
  • Cross-agency structured forums where issues, future conditions, alternatives, and plans can be responsibly developed and explored without the blinders of individual agency inconvenience.

Many despair that such integration is impossible, or fear that multi-agency efforts will diminish single-agency effectiveness.  To the contrary, today’s lack of common frameworks for integration often creates a brutal and insufficient incrementalism that diminishes the power and reputations of all individual agencies, and reduces the overall reputation of government for achieving societal objectives.

This blog post looks at some success with the similar problem of metropolitan planning for transportation, land use, and environmental planning.  The intent is to:

  1. Show that interagency planning and operational integration is possible and can be effective (if unavoidably imperfect) and
  2. Identify some likely preconditions and lessons for sustaining common interagency functions.

Perhaps this will encourage less fearful and more forward-looking discussions on how to better support needed common water management functions that cross agency boundaries and missions and serve society’s overall objectives for water management.

Metropolitan region planning

Metropolitan governance in the US also is notoriously fragmented.  Since the 1960s, metropolitan areas across the US have had Metropolitan Planning Organizations (MPOs) to regionally coordinate local, state, and federal governments and funding for transportation, land use, air quality, and sometimes other functions.   These are imperfect, but seem to have been useful and effective.  Most US metropolitan areas have MPOs (California has 18), including SACOG for the Sacramento region, the San Francisco Bay Area’s Metropolitan Transportation Commission, and the Southern California Association of Governments (including 6 counties and 191 cities).  DOT 2017 is a good general reference on MPOs.

MPOs coordinate local land use and transportation plans with state and federal plans and planning efforts.  Their composition, governance, activities, and funding vary considerably and are established locally, but they all must meet federal planning requirements for local agencies to receive federal transportation and other funds (much of which are returns of federal fuel tax revenues).

MPOs are housed in a host agency or operate as a separate agency.  They support common technical work in-house or by member agencies.  Common modeling of transportation demands and forecasts, congestion, and coordination of investments and plans helps all local MPO members as well as various state and federal transportation, environmental, housing, and social service agencies.  MPOs also serve as a forum to discuss and coordinate work on common issues and functions needed for both local and regional effectiveness.

MPO funding varies considerably but is a mix of federal, local, and state funds, averaging: Federal: 79% (62% federal planning, 10% federal transit planning, urban transportation 6%, congestion & air quality 1%), Local members: 10%, State: 7%, and Other: 4% (including fees for service 1%, grants 1%, and other 3%).  Integration often requires substantial outside funding, along with outside mandates and requirements.

Some lessons

  • It is possible to organize common technical and operational activities across agencies. Some sectors have done this regionally, such as metropolitan transportation planning, which has often broadened to include land use, housing, air quality, and other functions across agencies.  Such integration is rarely pretty, but is important and useful.
  • Agencies need reasons and frameworks to cooperate or integrate. Integration and coordination seem to require: a) a rationale for improving individual agency mission effectiveness, b) a mandate to work together from state or federal leadership, c) an organizational framework to reduce the transaction costs of integration, and d) money and streamlined regulation tied to effective cooperation or integration.
  • Sometimes looking outside of water can give insights for water management. Regional water integration might learn something from our transportation neighbors. Some MPO experiences might be adapted for basin or regional integration of local, state, and federal efforts for water supply, flood, water quality, and ecosystem functions.
  • Effective portfolio approaches will likely need to be developed and sustained in regional forums or agencies. Some examples today of such functionality exist in transportation (MPOs), and more narrowly as regional water quality control boards, regional water supply agencies (MWDSC, SDCWA, SCVWD), and for the Delta (DSC, DPC).  Some development along these lines might be useful for regionally organizing local and state water efforts more generally.

Just because integrating water management is hard, doesn’t mean California cannot do better.

Further Reading

Bruun, B. (2017), “The regional water planning process: a Texas success story,” Texas Water Journal, Volume 8, Number 1.

CALCOG (2019), Regional Governance, web site.

DOT (2017), MPO Staffing and Organizational Structures, US Department of Transportation, Federal Highway Administration, 162 pp.

Goldman, T. and E. Deakin (2000), “Regionalism Through Partnerships? Metropolitan Planning Since ISTEA,” Berkeley Planning Journal, Volume 14, Issue 1.

Hanak, E., J. Lund, A. Dinar, B. Gray, R. Howitt, J. Mount, P. Moyle, and B. Thompson (2011), Managing California’s Water:  From Conflict to Reconciliation, Public Policy Institute of California, San Francisco, CA.

ILG (2019), Metropolitan Planning Organizations: SB 375 Updates, Institute for Local Government web site.

Lund, J. (2019), Sustaining integrated portfolios for managing water in California, CaliforniaWaterBlog, 23 June.

Wikipedia (2019), Metropolitan Planning Organizations,

Jay Lund is the Director of the Center for Watershed Sciences at the University of California – Davis.  As an undergraduate regional planning and political science student, he was an intern with the Wilmington Metropolitan Area Planning Council (WILMAPCO), an MPO which we affectionately called “Wilmington Map Company.”


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What Water is Covered by the Clean Water Act?


Sunset over the Sacramento River. This navigable water body is a jurisdictional water under the Clean Water Act.

by Karrigan Bork

It is important if a stream, river, wetland, or even a dry ditch is protected by the Clean Water Act (CWA). The CWA is a federal law “to restore and maintain the chemical, physical, and biological integrity of the Nation’s waters.”[1] But the Act doesn’t cover all waters. Waters covered by the Act, called “jurisdictional waters,” are determined by the language of the Act and by court decisions and administrative rulemakings interpreting that language. Ongoing rulemaking efforts by the Trump administration, coupled with several recent court decisions, make defining jurisdictional waters very difficult.

CWA jurisdiction matters for two main reasons. First, the Act’s significant protections only apply to waters that are covered by the Act. The CWA bars the unpermitted discharge pollutants by any person to jurisdictional waters, but provides no protection to other waters.

Second, getting a permit to discharge a pollutant to jurisdictional waters requires compliance with a host of federal environmental laws. Projects in jurisdictional waters must work through both an environmental analysis under the National Environmental Policy Act (NEPA) and an analysis of the project’s impacts on threatened or endangered species under Section 7 of the federal Endangered Species Act (ESA), in addition to the requisite analysis under the Clean Water Act. And federal projects in jurisdictional waters must get permission from the state water board before they can proceed; projects not in jurisdictional waters require no such permission. Projects in non-jurisdictional waters require no NEPA analysis and do not require consultation under the ESA. Determining whether a given water is jurisdictional is a big deal.

Picture 2 KBork

Is this wetland a jurisdictional water? Depends how close it is to a traditional navigable water, what state it is in, and which Supreme Court Justice you ask.

CWA Jurisdiction Nationwide

CWA determinations seem like an easy question. The language of the CWA covers “navigable waters.”[2] But in legal settings, “navigable waters” means many different things, depending on the context, such as for state title to riverbeds, for commerce, or for public trust purposes.[3] In the CWA context, Congress explicitly defined “navigable waters” to means “waters of the United States.”[4] Not much help there. Congress also emphasized the breadth of the language; the legislative history notes that “[t]he conferees fully intend that the term ‘navigable waters’ be given the broadest possible constitutional interpretation.”[5]

The two agencies responsible for implementing the CWA, the Environmental Protection Agency (EPA) and the Army Corps of Engineers (COE), have interpreted this language in numerous rulemakings since passage of the Act. These rules have the force of federal law. In turn, these rulemakings have been challenged in court, and several Supreme Court cases have further fleshed out the meaning of “waters of the United States”.[6] There’s a long legal history, summarized here.

First, in the 1985 Supreme Court decision United States v. Riverside Bayview Homes, a unanimous Court determined that wetlands adjacent to navigable waters were jurisdictional.[7] Second, the 2001 Supreme Court decision Solid Waste Agency of Northern Cook County v. U.S. Army Corps of Engineers (SWANCC) determined that isolated non-navigable intrastate ponds were not jurisdictional.[8] And third, in the 2006 decision Rapanos v. United States, the Court again tried to iron out the definition.[9]

The Rapanos decision is a mess—few justices could agree on anything, and the decision ultimately included five separate opinions. There is no majority opinion. Four justices wrote one opinion, four justices another, one justice wrote his own opinion, and two others wrote additional concurrences or dissents. That means there’s no clear controlling decision, and anyone trying to apply the decision has a very hard time knowing what to do.

One opinion, written by Justice Scalia on behalf of Chief Justice Roberts, Justice Thomas and Justice Alito, determined that jurisdictional waters must be either traditional navigable waters, “relatively permanent bod[ies] of water connected to traditional interstate navigable waters”[10] (not ephemeral or intermittent flows), or wetlands adjacent to either of those water bodies. The plurality specifically rejected wetlands adjacent to waters that flowed only intermittently. But with only four justices, this opinion is not binding on anyone; that takes a five-justice majority.

A second opinion, from Justices Stevens, Souter, Ginsburg and Breyer, would have deferred to the EPA/COE definition of jurisdictional waters and rejected the idea that intermittent or ephemeral waters could not be jurisdictional.[11] They explicitly would cover geographic features like ephemeral streams, dry arroyos, and slot canyons, not covered under Scalia’s view. But again, this decision also wasn’t controlling.

In this strange situation, Justice Kennedy, who wrote his own opinion with no other justices, ended up holding the most sway. It’s difficult to explain why, but it boils down to counting votes on the Court. The four dissenting justices said they would agree with Justice Kennedy, although they thought he didn’t go far enough. That meant that a future regulation, based on Kennedy’s opinion, would likely be upheld by the Court on a 5-4 vote (Justices Kennedy, Stevens, Souter, Ginsburg and Breyer). No other justice offered an opinion that would get a similar 5-justice majority. This logic is less sound now, given the significant changes on the Court (four new Justices have joined the Court since Rapanos), but it still seems to be the controlling approach. It is unclear what the current Court would do in a similar situation.

Kennedy’s opinion decided that jurisdictional waters were those that have a “significant nexus” to traditional navigable waters, such that “the wetlands, either alone or in combination with similarly situated lands in the region, significantly affect the chemical, physical, and biological integrity of other covered waters more readily understood as ‘navigable.’”[12] Justice Kennedy’s opinion includes as jurisdictional waters any waters, even ephemeral or intermittent flows, if they are “likely to play an important role in the integrity of an aquatic system comprising navigable waters as traditionally understood.”[13] Determining whether any particular water was jurisdictional, under Kennedy’s opinion, requires a fact-based inquiry as to the relationship of that water to navigable waters nearby.

Based on the Kennedy opinion, EPA/COE wrote a new regulation defining jurisdictional waters, which went into effect on August 28, 2015.[14] If this rule, “The Clean Water Rule: Definition of ‘Waters of the United States,’” were in effect, we wouldn’t need to worry about all the Supreme Court decisions leading in to it, and we could just focus on the definition in the 2015 Rule. But, based on litigation to stop the 2015 Rule, the Federal 6th Circuit Court kept the rule from going into effect in an Oct. 9, 2015 decision. Just over a year later, President Trump took office and targeted the 2015 Rule for reform. Since then, it has been a regulatory and judicial whirlwind, with many new rules and lawsuits.

On Feb. 28, 2017, President Trump issued an executive order requiring review of the 2015 Rule. EPA/COE immediately proposed a new rule that would rescind/revise the 2015 Rule. Almost a year later, on Jan. 22, 2018, the Supreme Court reversed the 6th Circuit’s decision that kept the 2015 Rule from becoming law. With that decision, the 2015 Rule became the law of the land. But just nine days later, a new rule from the EPA/COE changed the effective date of 2015 Rule to 2020, so the 2015 Rule was no longer in effect. Then, on Aug. 16, 2018 , a South Carolina District Court invalidated the rule changing the effective date, but only for 26 states. That brought the 2015 Rule back into effect in those 26 states, but not other 24 states (two other lawsuits block application of the rule in those states; based on other decisions, the rule appears to be in effect in roughly 22 states, but it is not entirely clear).

In Dec. 2018, EPA/COE proposed a new rule defining WOTUS, based largely on Justice Scalia’s opinion in Rapanos. The proposed rule excludes ephemeral streams and related features and only includes adjacent wetlands if they “are physically and meaningfully connected to other jurisdictional waters.” The comment period for that rule ended on April 15, 2019, with the definition of jurisdictional waters currently in a holding pattern, waiting for the administration to publish the final new rule. Based on Obama Administration estimates, the proposed rule would reduce coverage of wetlands by 51% and coverage of streams by 18% nation-wide.

pic 3 Karrigan

What about this dry riverbed? Under Rapanos, Retired Supreme Court Justices Kennedy, Stevens, and Souter and current Justices Ginsburg and Breyer would say it’s a jurisdictional water, but Former Justice Scalia, current Justices Thomas and Alito, and Chief Justice Roberts would say no. Given that it takes five justices for a majority, and with the new Justices Kavanaugh, Kagan, Sotomayor, and Gorsuch joining the court since Rapanos, no one knows for sure.

Back Home in California

Where does this all leave California? The 2015 Rule is in effect in California in the near term, so projects starting now follow that rule for determining whether they affect jurisdictional waters.

But the replacement rule is expected in the next year from the Trump Administration, and that rule will likely displace the 2015 Rule everywhere, including in California. Estimates suggest that the new rule will reduce jurisdictional waters in southern California by 60-80% and jurisdictional streams statewide by two-thirds, generally driven by the new rule’s restriction of protection to permanent waters. The new rule, once in effect, will dramatically shrink the federal role in protecting California water quality, reduce the waters where compliance with NEPA and ESA consultation is required, and shrink the state’s ability to condition federal projects.

The new rule will face legal challenges, and those cases will likely take several years to resolve. At this point, it is unclear what rules, if any, will determine federal jurisdiction in the interim. Perhaps the 2015 Rule? If there is no active administrative rule, EPA/COE will apply the law from Rapanos, although which opinion they choose remains to be seen. Given their administrative discretion, it seems likely they will lean toward the Scalia opinion, but federal CWA jurisdiction in California will remain murky for the foreseeable future.

California is also acting on its own to address water quality and protect wetlands, filling the gap left by the federal government, writing new regulations under the California Porter–Cologne Water Quality Control Act (Water Code, Section 13000, et seq.). The Porter–Cologne Act defines “waters of the state” as “any surface or groundwater … within the boundaries of the state.” It explicitly includes all CWA jurisdictional waters but goes far beyond those waters. Notably, states inherently have more power than the federal government to regulate their waters, with fewer Constitutional limitations.

The California’s State Water Resources Control Board (SWRCB) adopted the new regulations April 2, 2019, and the rules will take effect nine months after their approval by the State Office of Administrative Law, a step that should happen soon. The state regulations protect any water ever covered by the CWA, some artificial wetlands, and seasonal wetlands in arid regions that lack wetland vegetation, and groundwater. The regulations also establish a state permitting process for those seeking to discharge pollutants, including dredge or fill materials, into these state-regulated waters.

The new regulations will maintain many protections for California waters, regardless of what happens at the federal level. But this isn’t really a happy ending—the loss of a federal hook for these waters will eliminate the federal role in permitting and may decrease their level of protection. And California may lose its ability to regulate federal projects that affect these waters. Beyond California, the level of protection afforded by states for their own water resources varies widely, and in many states the loss of federal jurisdiction will leave waters unprotected.

This is an important issue that bears watching.

Karrigan Bork is an Acting Professor of Law at the University of California, Davis.

End Notes

[1] 33 U.S.C. §1251 (a).

[2] 33 U.S.C. §1362 (12).

[3] Robin Craig, Navigability and its Consequences: State Title, Mineral Rights, and the Public Trust Doctrine, 61st Annual Rocky Mountain Mineral Law Institute (2015).

[4] Federal Water Pollution Control Act Amendments of 1972, tit. V. §502, Pub. L. No. 92-500, 86 Stat. 886 (codified at 33 U.S.C. §1362(7)(2000)).

[5] S. Rept. 92-1236, at 144 (1972).

[6] Among acronym happy lawyers, this is SCOTUS on WOTUS.

[7] 474 U.S. 121 (1985).

[8] 531 U.S. 159 (2001).

[9] 547 U.S. 715 (2006).

[10] 547 U.S. 715, 742 (2006).

[11] Id. at 802.

[12] Id. 733-735.

[13] Id. at 781.

[14] Clean Water Rule: Definition of “Waters of the United States”, 80 Fed. Reg. 37,054, 37,098 (June 29, 2015) (to be codified at 33 C.F.R pt. 328, and 40 C.F.R. pgs. 110, 112, 116, et al.) noting that this approach “balances the exclusion with the need to ensure that covered tributaries, and the significant functions they provide, are preserved.” Id.

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Groundwater Law – Physical – “the water budget myth”

by Jay Lundgroundwater-streamflow

This week’s short post is on groundwater law – from the viewpoint of physics.  Water policy, management, and human law often misunderstand how groundwater and surface water work physically.

Bredehoeft, et al. (1982) distill a longstanding lament of many groundwater experts, “Perhaps the most common misconception in groundwater hydrology is that a water budget of an area determines the magnitude of possible groundwater development.  Several well-known hydrologists have addressed this misconception and attempted to dispel it.  Somehow, though, it persists and continues to color decisions by the water-management community.”

Long ago, the venerable Theis (1940) summarized:  “Under natural conditions … previous to development by wells, aquifers are in a state of approximate dynamic equilibrium.  Discharge by wells is thus a new discharge superimposed upon a previously stable system, and it must be balanced by an increase in the recharge of the aquifer, or by a decrease in the old natural discharge, or by loss of storage in the aquifer, or by a combination of these.”

As Bredehoeft, et al (1982) conclude:

“1. Magnitude of [groundwater] development depends on hydrologic effects that you want to tolerate, ultimately or at any given time (which could be dictated by economics or other factors).  To calculate hydrologic effects, you need to know the hydraulic properties and boundaries of the aquifer. Natural recharge and discharge at no time enter these calculations. Hence, a water budget is of little use in determining magnitude of [sustainable groundwater] development.

2. The magnitude of sustained groundwater pumpage generally depends on how much of the natural discharge can be captured.

3. Steady state is reached only when pumping is balanced by capture, in most cases the change in recharge is small or zero, and balance must be achieved by a change in discharge. Before any natural discharge can be captured, some water must be removed from storage by pumping. In many circumstances the dynamics of the groundwater system are such that long periods of time are necessary before any kind of an equilibrium condition can develop.  In some circumstances the system response is so slow that mining will continue well beyond any reasonable planning period.

These concepts must be kept in mind to manage groundwater resources adequately. Unfortunately, many of our present legal institutions do not adequately account for them.”

Water budgets are important in managing water, but better water budgets include both surface water and groundwater, which interact naturally and through management.  Most groundwater pumping is ultimately from surface water, taken at some time or place.  Water budgets consisting only of groundwater neglect the laws of physics that govern the sustainability of water management.

In California, local, regional, and state managers and regulators of Sustainable Groundwater Management programs and plans will need to integrate surface water with groundwater.  It’s the physical law, and it is always, eventually enforced.

Further reading

Bredehoeft, J.D., S.S. Papadopulos and H.H. Cooper. 1982. Groundwater: the Water Budget Myth. In Scientific Basis of Water-Resource Management, Studies in Geophysics, Washington, DC: National Academy Press, pp. 51-57.

The Nature Conservancy, RMC Consultants, Inc. (2016), Groundwater and Stream Interaction in California’s Central Valley: Insights for Sustainable Groundwater Management, The Nature Conservancy, Sacramento, CA, 149 pp.

Maven’s Notebook, CA WATER LAW SYMPOSIUM: Questions of common supply: SGMA requirements for interconnected surface water and groundwater, panel discussion summary, June 19, 2019.


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$24.6 Billion National Flood Insurance Program Debt Explained in One Chart

by Kathleen Schaefer

As we are enter another hurricane season, the National Flood Insurance Program (NFIP) is on its 12th short-term extension since September 30, 2017.  And after having $16 billion in debt forgiven, it remains $24.6 billion in debt (Horn 2019). Many people are asking, how did we get here? While “its complicated,” much can be explained by this graph from Oldenborgh et al. (2017), p.6.

Figure for flood frequency

Figure Caption: Fit of the annual maximum three-day average from 85 precipitation gages on the US Gulf Coast. Dashed red line is Generalized Extreme Value (GEV) estimates representing 2017. Solid blue line is GEV estimates scaled down to 1900 based on correlated global temperature changes. The horizontal dotted  green line shows the intensity of the observed event at Baytown, TX, far above any previous observation. Source: van Olderborgh et. al

How this graph explains the $24.6 billion debt, begins with the knowledge that the NFIP is essentially an In-Out Flood Game. FEMA is the referee. They oversee the Flood Insurance Rate Maps (FIRMs) that show the Special Flood Hazard Area (SFHA) or 100-year flood. The FIRMS show who is “in” the floodplain and must pay and who is “out” and freer of building and insurance requirements. Almost every community in America participates in this Flood Game.  Communities that opt out they risk losing access to post-disaster aid. Many cities like Roseville and Sacramento respect the power of floods and embrace the Flood Game—actively participating in activities like the Community Rating System (CRS), saving their citizens hundreds of dollars each year. Other communities focus on short-term growth and commercial development built on ignoring or denying flood risks.  Not wanting to restrict development or force their residents to purchase flood insurance, they view any action that increases the designated floodplain as a “loss”, regardless of how prudent the decision may be in the long term.

Hydrology estimates are critical in this Flood Game. The in-out boundaries can only be adopted by the community after designated experts agree on the 100-year discharge value. Clear, well-defined, stationary, in-out boundaries for the 100-year floodplain have a key role in keeping the players in the game. But hydrology involves uncertainties and is not well charaterized by a single number. So, once everyone has agreed on a boundary, there is great reluctance to change it—even with indisputable climate change.

With that housekeeping out of the way, on to explain the chart.

The chart’s Dutch researchers observed that extreme precipitation along the Texas Gulf Coast has increased 12% to 22% since observations began in 1880. To examine global warming’s contribution to the increase, they compared an ensemble of recorded precipitation gage data from the Gulf Coast to the output from global climate models, finding that the downscaled climate model data fit moderately well. The dotted horizontal  line at 350 mm/day shows how extraordinary Hurricane Harvey was. It dropped more than 60 inches of rain and caused more an estimated $125 billion in damages (Blake and Zelinsky 2018). Harvey was an off-the-chart event. Rare extremes are possible.

The solid blue line is the annual maximum three-day average perception from 85 Gulf Coast precipitation gages scaled down to represent the rainfall distribution that would have been observed in 1900. The dashed red lines are the upper and lower estimates of the annual maximum three-day average perception estimated for 2017 conditions. Van Oldenborgh et al. concluded that global warming has increased the intensity of rainfall in the region by 15% over the last half-century. They suggest that these increases in extreme precipitation should be considered when rebuilding.

This graph also shows that precipitation at recurrence intervals greater than 100-year are possible.  Larger return periods also have greater uncertainty. So precipitation estimates foundational to FEMA Flood Insurance Rate Maps are less certain than current in-out maps would lead one to believe.

Communities who play the Flood Game with reluctance do not want complications from considering additional discharges or uncertainties than the single 100-discharge previously agreed to. However, armed with this graph, the Harris County Flood Control Agency and the City of Houston could have used this moment to justify a higher design discharge value as the hydrology number. But they did not (Harris County Flood Control Agency 2016, 3).

Although NFIP ratepayers and the federal government must ultimately pay for these decisions, and FEMA encourages communities to submit updated hydrology estimates for approval and adoption (44 CFR 66.1), changing the hydrology opens the possibility of redrawing flood rules, maps, and regulatory susceptibility—a messy complicated affair few wish to tackle.

If Houston would have adopted a higher 100-year discharge number, they would have had to admit that FEMA maps are no longer current and that the in-out boundaries need to change. This would have forced more Houstonians to elevate their homes, whether they could afford to or not. It would force hundreds more to buy flood insurance, whether they could afford it or not. Further, as the adoption of FEMA maps is a long process, it would add uncertainty to rebuilding at a time when people want only to get on with rebuilding. Not wanting to be criticized for not taking action, the Houston City Council did increase freeboard requirements for the unfortunates designated as “in” (the SFHA). But, as much as 50% of the homes at high or moderate flood risk are in the perceived “flood free” zone, and by not adopting new hydrology the in-out boundary will remain the same and many will unknowingly rebuild unwisely (CoreLogic).

As a recent Public Media article highlights, once rebuilding is underway, it is hard to change course. Thus, the process repeats (Conrad 1998). Ultimately, Californians will be forced to continue to subsidize the poor development decisions of Houston and other areas for fear that if we do not, Houstonians will not come to our aid when our levees fail. As we have no business telling Houston how to develop, perhaps it is time to remove ourselves from this Faustian bargain, and develop our own modern comprehensive flood risk and insurance program—one that goes beyond the In-Out Flood Game and considers a range of flood events and their uncertainties.

Further reading

Blake, Eric S., and David A. Zelinsky. 2018. “Hurricane Harvey.” Tropical Cyclone Report AL092017. National Hurricane Center. Retrieved from

Conrad, David R. 1998. Higher Ground: A Report on Voluntary Property Buyouts in the Nation’s Floodplains: A Common Ground Solution Serving People at Risk, Taxpayers and the Environment. National Wildlife Federation. Retrieved from

Harris County Flood Control Agency. 2016. “Hcfcd-Hydrology-Hydraulics-Manual_03-2016.pdf.” Retrieved from

Horn, Diane. 2019. “The National Flood Insurance Program: History and Overview.” Retrieved from

Oldenborgh, Geert Jan van, Karin van der Wiel, Antonia Sebastian, Roop Singh, Julie Arrighi, Friederike Otto, Karsten Haustein, Sihan Li, Gabriel Vecchi, and Heidi Cullen. 2017. “Attribution of Extreme Rainfall from Hurricane Harvey, August 2017.” Environmental Research Letters 12 (12): 124009.

Kathleen Schaefer is a PhD student in Civil and Environmental Engineering at the University of California, Davis.  She has a long acquaintance with flood insurance.

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Ties Between the Delta and Groundwater Sustainability in California

by Mustafa Dogan, Ian Buck-Macleod, Josue Medellin-Azuara, and Jay Lund

Groundwater overdraft is a major problem globally and has been a persistent and growing problem in California for decades. This overdraft is predominantly driven by the economic value of water for agricultural production and cities. Spurred by the recent drought, California passed legislation requiring the elimination of groundwater overdraft by 2040. To explore potential water supply effects of ending long-term groundwater overdraft in California’s Central Valley, we compared several water policies with historical and warmer–drier climates, employing a statewide hydroeconomic optimization model, CALVIN, in our new paper. Hydro-economic optimization models like CALVIN allocate water to agricultural and urban users considering hydrologic conditions, infrastructure, and environmental restrictions among other factors, such that systemwide water scarcity and operation costs are minimized.

Groundwater overdraft is a common response to surface water scarcity when the economic value of water use in agriculture and cities exceeds pumping costs. In California, supply and demand disparity combines with a great seasonal and geographical imbalance of water supplies and demands. Water is much more available during winter in northern California, but water demands are mostly in central and southern California during spring and summer.

The Sacramento-San Joaquin Delta (Delta) is the major hub in California’s water system (Figure 1), with environmental and water allocation policies also affecting operation, planning, and management decisions. Changes in regulations and climatic conditions and increasing water demands make Delta water management complex.

Figure 1.png

Figure 1. California’s groundwater basins, aggregated wildlife refuges, and minimum in-stream flow requirements represented in CALVIN, and the Delta water balance (Dogan et al., 2019)

Management Policies

Policy cases examined here put different restrictions on Delta water operations and eliminate groundwater overdraft under 82-year (1921–2003) historical and warmer–drier climates with 2050 agricultural and urban water demands (Table 1). Policy 1 allows historical overdraft rates in CALVIN’s 82-year modeling horizon. A no-overdraft policy is applied to the Central Valley groundwater aquifer in Policies 2–5, requiring that groundwater storage at the end of each 82-year run cannot be less than groundwater storage at each run’s beginning. Policies 3–5 add different Delta export constraints to this no-overdraft policy. Policy 3 maintains historical Delta outflows, by month, in addition to the no-overdraft policy, so reductions in Delta outflows cannot substitute for lost historical supplies from groundwater overdraft. Policy 4 further restricts Delta export operations by constraining water exports to historical quantities, in addition to maintaining a no-overdraft policy. This prevents the optimization model from curtailing water use north of the Delta to supply water south of the Delta to accommodate supplies lost there from ending groundwater overdraft. Policy 5 reduces Delta exports by 95%, largely eliminating them, in addition to maintaining a no-overdraft policy.

Table 1. Policy cases evaluated under historical and perturbed (warmer–drier) climates (modified from Dogan et al., 2019)

Policy Description Importance
Policy 1 Operations with historical overdraft Base case operations
Policy 2 No overdraft Operations without overdraft and with no new Delta restrictions
Policy 3 No overdraft and no reduction in Delta outflow Forces water use reallocation across basins without reducing Delta outflow
Policy 4 No overdraft and no additional Delta exports Operations and use changes occur only within basins, cannot adjust statewide
Policy 5 No overdraft and minimal Delta exports Largely eliminates Delta export water supplies


All analyses have weaknesses and limitations, but the model’s results support several consistent and insightful conclusions, many of which merit further analysis and discussion.

  • California’s two largest water problems, groundwater sustainability and the Sacramento-San Joaquin Delta, are closely tied.
  • With “no overdraft” policy (Policy 2), the 82-year period has two large recovery durations, lasting 62 and 12 years, demonstrating the importance of long-term groundwater planning and the difficulty of assessing groundwater sustainability.
  • If Delta outflow cannot be reduced for environmental and operational reasons (Policy 3), opportunities for Sacramento Valley users to sell some water to south-of-Delta users would be economically worthwhile under historical climatic conditions.
  • If permitted environmentally, diversions from surplus Delta outflow (Policy 3) can reduce (but not eliminate) water scarcities.
  • If Delta exports cannot be increased for environmental and management reasons (Policy 4), regional water trades help reduce water scarcities.
  • Surface water availability and the reliability of Delta exports are significantly reduced with a warmer-drier climate.
  • A warmer-drier climate combined with ending groundwater overdraft and some water management policies would further exacerbate water scarcities and increase environmental and economic costs.
  • Delta water supplies and operations become more important with the end of overdraft and climate change.
  • Economically useful adaptations include more diversions from surplus Delta outflow, increased water transfers involving Delta, water markets and trades, conjunctive use of groundwater and surface water, and recycled wastewater. These would come at a cost and often with additional controversy.

Further Readings

Dogan, M.S., Buck, I., Medellin-Azuara, J., and Lund, J.R. (2019), “Statewide Effects of Ending Long-term Groundwater Overdraft in California,” Journal of Water Resources Planning and Management, 145(9).

Lund, J.R. (2016), “California’s agricultural and urban water supply reliability and the Sacramento-San Joaquin Delta,” San Francisco Estuary Watershed Sci. 14(3).

Dogan, M. S., J. D. Herman, and M. A. Fefer. 2017. “CALVIN source code.” Accessed July 21, 2018.

Buck, I. (2016), “Managing to end groundwater in California’s Central Valley with climate change.” M.S. thesis. Dept. of Civil and Env. Engineering, University of California, Davis.

Dogan, M. S. (2015), “Integrated water operations in California: Hydropower, overdraft, and climate change.” M.S. thesis. Dept. of Civil and Env. Engineering, University of California, Davis.

Mustafa Dogan recently completed his PhD in Civil and Environmental Engineering at the University of California, Davis and is now an Assistant Professor of Civil Engineering at Aksaray University in Turkey. Ian Buck-Macleod is an engineer with Stantec. Josue Medellin-Azuara is an acting Associate Professor of Environmental Engineering at the University of California, Merced.  Jay Lund is a Professor of Civil and Environmental Engineering at the University of California, Davis.

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Challenges and opportunities for integrating small and rural drinking water stakeholders in SGMA implementation

By Kristin Dobbin, Jessica Mendoza and Michael Kuo

The Sustainable Groundwater Management Act (SGMA) is an historic opportunity to achieve long-term sustainable groundwater management and protect drinking water supplies for hundreds of small and rural low-income communities, especially in the San Joaquin Valley. Past research indicates that few of these communities are represented in the Groundwater Sustainability Agencies (GSAs) formed to implement the new law. This raises questions about the extent such communities are involved in groundwater reform and potential concerns about how small and rural drinking-water interests are being incorporated into Groundwater Sustainability Plans (GSPs).

Our new report summarizes results of interviews with more than thirty small (< 10,000 people), low-income community representatives in the San Joaquin Valley providing an important window into community perspectives on, and experiences with, SGMA implementation. How and why are communities involved with SGMA or not? What challenges and opportunities exist for increasing community involvement with SGMA implementation?

The findings suggest communities are highly interested in SGMA and desire to be involved in its implementation, which many deemed indispensable for the future of their communities. Small and rural communities are participating in a variety of ways, including serving on committees, attending meetings and workshop and monitoring meeting minutes and agendas. While interviewees’ experiences in these different capacities are exceedingly diverse, six common challenges and concerns about SGMA implementation arose:

  1. Resource constraints to participation: Lack of staff, small budgets, in-house experts and an inability to pay for outside services/support limited communities’ formal participation in GSA governance and attendance and involvement in SGMA meetings.
  2. Accessibility: Additional factors limiting the accessibility of the SGMA process included day-time meetings, language barriers, the proliferation of board and committee meetings, and irregular and unclear meeting schedules and notices.
  3. Transparency: A lack of transparency in GSA decision-making as well as limited access to the data and information being used to develop Groundwater Sustainability Plans (GSPs) were common concerns for interviewees impacting their desire to participate and trust in the process.
  4. Lack of formal representation: The relegation of communities to advisory, rather than decision-making, roles in the SGMA process was also a common concern.
  5. Limited opportunities to provide meaningful input and feedback: Whether participating as a decision-maker, committee member or as a member of the public attending meetings, many were frustrated at the lack of opportunities to provide meaningful input into decisions or on draft documents due to short turnaround times, not being provided necessary background or materials, and limited opportunities for public comment and open discussion.
  6. Lack of addressing drinking water interests and priorities: Overwhelmingly, interviewees reported that drinking water interests, especially water quality and domestic wells, were not part of their local SGMA conversations, leading many to be skeptical that SGMA would have drinking-water benefits.

The good news is that best practices and recommendations from all of the interviewees highlight ample opportunities to address these issues and increase the integration of drinking-water stakeholders and interests into sustainable groundwater management. Targeted efforts to reduce barriers to participation, improve communication and transparency, and promote diverse representation could go a long way to ensuring the “consideration” and “active involvement” of this important, historically marginalized, stakeholder group. For example, communities can educate their GSA about drinking-water priorities and the variety of regulations and requirements public water systems must comply with and coordinate with other small and rural communities to elevate and advocate for drinking-water needs. GSAs should incorporate available public data into Groundwater Sustainability Plans (GSPs) while developing plans to fill data gaps, provide ample time for feedback on staggered and sequential GSP sections and streamline and increase interaction with stakeholders in meetings. State agencies should consider requiring or incentivizing collaborative community projects be included in GSPs, and community representation in GSP development and implementation as well as provide funding to support meaningful community involvement in all phases of SGMA implementation. The extent to which state, regional and local interests can work together to find and implement inclusive solutions will determine how well SGMA accomplishes its stated goal to “protect communities, farms, and the environment against prolonged dry periods and climate change, preserving water supplies for existing and potential beneficial use” (SGMA, uncodified findings).

To read more and see the full list of recommendations and best practices, read the full report here. A Spanish-language version of the report will be available soon.

Kristin Dobbin is a PhD student in Ecology at UC Davis studying regional water management and drinking water disparities in California. Jessica Mendoza and Michael Kuo are undergraduate research assistants in the UC Davis Center for Environmental Policy and Behavior.

Further Readings

Moran, T. & Belin, A. (2019). A Guide to Water Quality Requirements Under the Sustainable Groundwater Management Act.

Dobbin, K. (2018). Small Disadvantaged Community Participation in Groundwater Sustainability Agencies (English / Spanish).

Feinstein L, R. Phurisamban, A. Ford, C. Tyler and A. Crawford. (2017). Drought and Equity in California

Kiparsky, M., D. Owen, N. Nylen, J. Christian-Smith, B. Cosens, H. Doremus, A. Fisher, A. Milman. (2016). Designing Effective Groundwater Sustainability Agencies: Criteria for evaluation of local governance options.

Dobbin, K., J. Clary, L. Firestone and J. Christian-Smith. (2015). Collaborating for Success: Stakeholder engagement for Sustainable Groundwater Management Act implementation.


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Drought, Fish, and Water in California


Pit River in Modoc County, August 21, 2014.  Drying pools contained mainly non-native fishes.

by Peter Moyle

With a big collective sigh of relief, Californians rejoiced that we have largely recovered from 2012-2016 drought[1].  Streams are flowing.  Reservoirs are full. Crops are watered. Native fishes are reproducing   But this not a time for complacency; if the 2012-2016 drought, the hottest and driest on record, had lasted another year or longer, California ‘s farms, cities, and ecosystems would have been in a dire state, with water in short supply everywhere (Mount et al., 2017, 2018).  This should thus be a time to develop new and better strategies for reducing impacts of severe drought on both natural and developed systems, following the California Water Model (Pinter et al. 2019) of “resilience through failure.”  California has a history of learning from past failures of water management, especially floods, and of avoiding repeating mistakes as a consequence.

Drought, of course, is not confined to California, but is a global problem, which is increasing as the planet warms.  Fish and other aquatic organisms bear the brunt of drought because severe competition with people for water destroys their habitats.  Worldwide, they are facing extinction at increasing rates. This is one lesson from a review of drought effects on freshwater fishes from Canada, California, and Australia (Lennox et al. 2019).  This review shows how fish responded to drought in natural and highly altered waterways worldwide to gain insights into how to keep native fish from going extinct as droughts become more severe. California’s fishes provide especially good insights because most are highly adapted for persisting through long natural droughts; however, many are now threatened with extinction because of actions that exacerbate drought impacts.

To make our review more accessible, we condensed our findings into a list of maxims or aphorisms.  These maxims contain general truths to help managers deal with the enormity of fish conservation problems in an increasingly drought-stricken world. Here are the maxims, somewhat modified from Lennox et al. (2019).

  1. Future droughts will be longer, more frequent, and more severe, creating more stressful conditions for freshwater fishes.
  2. Climate change and human alteration of aquatic ecosystems combine to increase the negative effects of drought.
  3. Fishes survive natural droughts in their native waters through physiological and behavioral adaptations, but all have limits.
  4. Different species respond to drought in different ways, so post-drought fish assemblages are hard to predict, especially in highly altered habitats.
  5.  When natural environmental variability is suppressed by human activity, aquatic ecosystems become homogenized, dominated by a few drought-tolerant fish species, often non-native.
  6. Fish survive droughts by dispersal or migration to other habitats or by finding refuges in remnant habitats where conditions are physiologically suitable.
  7.  The most abundant stream fishes in regions with frequent natural droughts are those with the ability to rapidly disperse and recolonize as both adults and juveniles.
  8. The best drought refuges are usually large rivers, lakes, spring-fed streams, and deep permanent stream pools with ground water inflow.
  9. The bigger and more diverse structurally the drought refuge, the more fishes it can shelter.
  10. Connectivity among habitats is essential for recovery of fish faunas in streams and lakes stricken by drought.
  11. Ground water is essential for maintaining stream refuges through drought.
  12.  Human activity often produces perpetual drought conditions in streams through surface and groundwater removal.
  13. Poor water quality, especially low dissolved oxygen and high temperatures, followed by predation, are primary causes of fish mortality in drought refuges.
  14. Changes in severity or frequency of drought alter fish assemblages, with the effects of the changes depending on the history and physical characteristics of the system.
  15. Fisheries will decrease if human-mediated drought results in habitats unable to support large populations of harvestable fish.
  16. Translocation of species to new waters and artificial propagation are desperation measures unlikely to ameliorate the ecosystem effects of human-expanded drought.

These maxims point to the need to have some aquatic ecosystems in California that are managed largely for native fishes, in ways that make them drought-resistant.  California’s native fishes are actually adapted for surviving severe droughts, but they evolved in large, inter-connected river systems where there were always refuges somewhere.  We cannot bring back those large river systems as habitat but we can create refuges that are closely monitored and managed, with native fishes and the aquatic ecosystems they represent, getting a fair share of the water (Mount et al. 2017).


Oristimba Creek, Merced County, during 2012-16 drought.  Most of creek was dry but there were a few native fish refuges where groundwater  seeped into bedrock pools.  Unfortunately, the pools contained non-native green sunfish which were consuming the native fishes. Photos by P. Moyle.

Further Readings

Lennox R.J., D.A. Crook, P. B.  Moyle, D. P. Struthers, and S. J. Cooke 2019. Toward a better understanding of freshwater fish responses to an increasingly drought-stricken world. Reviews in Fish Biology and Fisheries 29:71-92\  Open Access.

Mount, J., B. Gray, C. Chappelle, G. Gartrell, T. Grantham, P. Moyle, N. Seavey, L. Szeptycki, and B.Thompson. 2017. Managing California’s Freshwater Ecosystems: Lessons from the 2012-16 Drought. Public Policy Institute of California 52 pp.

Mount, J. B. Gray, and 28 others. 2018.  Managing Drought in a Changing Climate: Four Essential  Reforms. San Francisco: Public Policy Institute of California. 30 pp.

Pinter, N., J. Lund, and P. Moyle. 2019.  The California water model: resilience through failure. Hydrological Processes 2019: 1–5.

Peter Moyle is Distinguished Professor Emeritus at the University of California, Davis and is Associate Director of the Center for Watershed Sciences.

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Sustaining integrated portfolios for managing water in California

FY 2018 Reliability Pie Chart

by Jay Lund

Summary:  This post reviews some lessons from portfolio water management in California and identifies roles for state government in facilitating development and implementation of effective portfolios.  To better align state regulations and funding with these goals, a more adaptable structure for state planning is suggested.  Effective integration of local, regional, and state water management goals must more flexibly employ regulations to support environmental operations as components of local, regional, and state water management portfolios.

Recently Governor Newsom issued a call for a state portfolio of actions to manage water under rapidly changing climate and other conditions.  Portfolio approaches attempt to integrate and balance a variety of actions (supply and demand management, surface water and aquifers) for single purposes (water supply, floods, safe drinking water) and often for multiple benefits, involving multiple interests.  A previous essay reviewed the successes and limitations of portfolio approaches to water management in California.  Overall, where applied well, mostly at local and regional levels for single purposes, portfolio approaches have been quite successful.

Portfolio approaches are especially good for adding flexibility to water management infrastructure and institutions.  Like a diversified financial portfolio, water management portfolios employ a broader range of options to improve stability, adaptability, and performance.  Moreover, the thinking and discussions needed to establish and manage portfolios is a good basis for improving integration within and among water agencies and preparation and adaptability for inevitable extreme events and major changes.

Many of California’s local and regional agencies have developed highly effective and cost-effective portfolios of activities for water management.  The 2012-2016 drought’s limited economic impacts (despite some difficult local impacts and some devastating ecosystem impacts) illustrate the effectiveness of local water supply portfolios of water supply and demand actions since the 1987-1992 drought (Lund et al. 2018).  State efforts and funding have helped support local and regional water management portfolios (such as IRWMPs), but overall, state agencies have been less effective (and less well funded) in developing effective portfolio approaches for managing ecosystems and other areas of water management.

Outside of California, the Louisiana coastal master plan is particularly good at taking a multi-time scale approach and the European Union’s Water Framework Directive basin plans provides diverse examples of developing multi-benefit plans for locally-adaptable regulatory frameworks.

How might California better employ water management portfolio approaches, expanding on local and regional successes for single purposes to broader multi-purpose successes regionally and statewide?  This essay summarizes some lessons and useful roles for State activities regarding water portfolio management, and makes a modest proposal for modernizing and integrating State and regional water planning.

Some lessons

  1. Portfolio management employs a range of supplies and demand management activities in an integrated and balanced way. Diversification usually brings flexibility, adaptability, and value.
  2. Most newer portfolio elements, such as water conservation, conjunctive use, interties, and water reuse, are better implemented locally and regionally. State roles for these newer efforts are important, but more in supportive roles of regulatory and technical support than instigation and implementation leadership.
  3. Portfolios of actions (especially preparations for extremes) commonly involve outside water agencies and partners, both nearby and far away. Portfolio management gives opportunities to make and keep friends.
  4. Analytical efforts are important, despite being always approximate. MWDSC, SDCWA, and other local and regional agencies base their portfolios on modeling efforts often more sophisticated than state efforts. Statewide portfolio modeling shows good promise (CALVIN).  These efforts rest on well-organized and available data.
  5. Areas lacking in portfolio management (such as for ecosystems and rural drinking water) have been performing more poorly than areas that have performed comparatively well (such as urban and agricultural water supplies). This may require major changes in thinking, funding models, and perhaps legislation.
  6. Adaptability will be needed for California to prepare for unavoidable changes in climate, population, economic structure, ecosystems, and technology, as well as normal and increasing extreme wet and dry years. Resistance to change and extremes is futile, and portfolio approaches prepare for changes and opportunities in water management.
  7. Integrating regulatory and system planning and operations into a broader portfolio is promising for accomplishing diverse water system purposes. This seems especially important for successful ecosystem management. The Delta’s co-equal goals and voluntary settlement agreements for environmental flows are efforts in this direction.  Continuing separation of infrastructure and operation plans from environmental management seems far less effective and increasingly untenable.

State Roles in Water Portfolio Management

Important state functions in portfolio water management include:

  1. Supporting local and regional fund-raising legally and administratively. Water management and infrastructure are expensive, and local governments have considerable ability and accountability for funding such projects.  State funding can rarely have more than a nudging role.  Propositions 218 and 26 are examples of how State policies can undermine self-funding of local and regional efforts.
  2. Common water accounting, science, and technical support across state agencies, is a foundation for public discussions, coherent management, agreements among agencies, and water trading. This includes integration of local and regional data collection efforts (often using SCADA systems) with state and federal water data collection, management, modeling, and analysis. Texas, Colorado, and other western states act more centrally in these roles.
  3. Bringing statewide interests in sustaining ecosystems and public health into local and regional water management portfolios. Historical state reliance on environmental regulations and permits have not brought desirable levels of environmental progress and rural drinking water supply.  Additional means are needed.
  4. Integrating portfolios across regions and agencies. Establish frameworks and incentives for local agencies to work together regionally, and for state agencies to cooperate in such efforts.  This includes facilitating flexibility in operations and projects, including trades and transfers, in operational, planning, and policy contexts. SGMA, environmental flow management and the Delta are examples where better organized state water planning could usefully parallel regional organization of local agencies and interests.

Separating environmental regulations from water infrastructure, operations, and management has not been successful enough.  Environmental management must become more than regulations, to become more operationally focused on the active operation and development of habitats and water for ecosystems, often involving land owners and other agencies.  Environmental regulations are a central part of state, regional, and local water management portfolios.  If environmental regulations are not shaped to be compatible with other actions, such as infrastructure design and operations and the management of water demands, then the collective portfolio will be at best sub-optimal and at worst a failure.

A Modest Proposal

The state needs a new vision for the California Water Plan, compatible with SGMA/groundwater planning, voluntary environmental agreements, Prop 1 storage project implementation, drought preparedness, and the many other well-intended state and regional efforts.  Under the current state planning and regulatory framework all these efforts face a brutal, expensive, and impossibly slow incrementalism that impedes effective portfolio development and implementation.

Figure 1 shows a potential framework for water and regulatory planning in California. This new framework would place development and approval of a statewide interagency plan under the California Water Commission, perhaps modestly reconstituted, with the plan becoming part of the budget process for the major state agencies involved.  In recent years, the California Water Commission has developed a reputation and role as a neutral party crossing agency and stakeholder lines.  This interagency plan would also become a nexus for reconciling regulatory actions and rolling up local and regional plans.

Supporting this interagency plan, and the activities of state agencies would be a common California Water Science and Technical Program.  The isolated development of science and technical work in separate agencies and programs has not been serving California well.  A common science and technical program is needed to support, integrate, and balance agency efforts, the administration of multi-agency plans for SGMA and groundwater, the Delta, and ecosystems.

Most of a new California Water Plan would consist of multi-agency regional plans for 11 hydrologic regions.  These plans would involve the SWRCB, RWQCBs, DWR, CDFW, CDFA, and local counties and water agencies, focusing on regional coordination of local plans as well as coordinated regional plans for state interests in ecosystems, economic development, and public health.  Regional integrated water plans would be a framework for neighboring agencies to work together; the pairing of the Santa Ana Watershed Project Authority with the State’s Regional Water Quality Control Board 8 (Santa Ana) is perhaps today’s closest equivalent.  Regional offices of state water agencies would be re-aligned for this purpose.  These regional planning efforts would be supported by regional water science and technical efforts to support local and regional SGMA, water quality, ecosystem, and environmental justice plans and efforts.

This approach would preserve what local, regional, and state agencies are already doing well, while bringing agencies together to make improvements and better address areas that lack integration and well-developed portfolios.  Each state role in portfolio planning would be strengthened.

Portfolio water plan.png

Figure 1. Integrating Local, Regional, and State Water Plans, supported by public science

Areas where portfolios have lagged include: environmental management; integration across water management purposes; groundwater; and safe rural drinking water. Extending portfolio planning to and across these areas should help, although it may require changes in how agencies view planning and operations. Regional integration is most important, particularly for obtaining multiple benefits and integrating projects and regulations with portfolios.  Common science and technical information are fundamental here.

Implementation of the Sustainable Groundwater Management Act and new environmental flow regulations together provide an excellent opportunity for modernizing California’s water planning and regulation functions into a more integrated portfolio-based framework.  Some fundamental changes in state regulation and planning would better prepare California for developing and operating effective water management portfolios in an era of rapid change.

Further Readings

Central Valley Joint Venture.

Escriva-Bou, A., H. McCann, E. Hanak, J. Lund, B. Gray (2016), Accounting for California’s Water. Public Policy Institute of California, San Francisco, CA.

Hanak, E., J. Lund, A. Dinar, B. Gray, R. Howitt, J. Mount, P. Moyle, and B. Thompson (2011), Managing California’s Water:  From Conflict to Reconciliation, Public Policy Institute of California, San Francisco, CA.

Lund, J. (2019), “A water portfolio planning report card for California,” 26 May,

Lund, J. (2019), “Portfolio Solutions for Safe Drinking Water – Multiple Barriers,” 7 April,

Lund, J. (2019), “Portfolio Solutions for Water – Flood Management,” 3 March,

Lund, J. (2019), “Portfolio Solutions for Water Supply,” 10 March,

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)

Pinter, N., J. Lund, and P. Moyle (2019), “The California water model: Resilience through failure,” Hydrologic Processes, March, and blog post.

Bruun, B. (2017), “The regional water planning process: a Texas success story,” Texas Water Journal, Volume 8, Number 1.

White, Gilbert (1966), Alternatives in Water Management, Publication 1408, National Academy of Sciences – National Research Council, Washington, DC, 52pp.

Jay Lund is a Professor of Civil and Environmental Engineering at the University of California, Davis.

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Flood Mapping in California: The Good, the Bad, and the Ugly

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Figure 1. The first FEMA flood maps were based on modeling run on mainframe computers (Maeder, 2015). Flood modeling has evolved far, but many FEMA maps remain based on early methods.

by Kathleen Schaefer and Nicholas Pinter

FEMA flood insurance rate maps (FIRMs) are the principle tool for managing the National Flood Insurance Program (NFIP).  They identify properties whose owners may be required to purchase flood insurance and help set flood insurance premiums across the US.

FEMA is required to assess FIRMs at least every five years, with revisions when necessary.  However, for almost half of California’s communities, the engineering studies supporting FIRMs are over 20 years old.  Less than 30,000 miles of the State’s 180,000 stream miles have been mapped by NFIP and less than 23% of the flood mapped river miles are designated as ‘Valid’.  A 2013 California Department of Water Resources (DWR) assessment, funded by FEMA, estimated the cost to bring California FIRMs into ‘Valid’ status using current methods to be over $406 million.  Most California communities are unlikely to ever get a new FEMA study.

History of US Flood Mapping

The first US FIRMs used topographic information collected by surveyors using measuring rod and surveying level, a time-consuming and sometimes dangerous process.  Water-surface elevations and floodplain boundaries were hand-drafted onto topographic base maps.  Starting in the 1980s, computer modeling improved the process, but FEMA map production remained an expensive and time-consuming.

In California, from 1973 to 1983, FEMA issued new FIRMs to 376 communities.  But it became apparent that FEMA would not meet Congressionally mandated deadlines to provide all flood-prone communities with detailed flood information.  In 1985, FEMA initiated a new method to reduce the cost and time required for new flood studies.  From 1983 to 1993, FEMA issued new FIRMs to 103 California communities using this revised method.

Beginning in 1986, Congress required NFIP to pay program expenses from insurance premiums.  Without outside federal appropriations, new flood studies lagged, and existing paper maps across the US continued to age (FEMA 2006).  For the past 20 years, an average of just 7-8 new flood studies have been completed each year in California.

By 2015, California flood maps were translated into a seamless digital flood layer.  This meant that anyone could pull up a map and determine if their home touched the floodplain boundary.  By making digital maps readily available to the public, Map Mod transformed many 40-year old, hand-drafted mapping into a digital product perceived to be accurate to within inches.

Age of California Flood Maps

The Community Status Book (FEMA 2018a) lists, by political jurisdiction, the dates of the first map and the date of current effective map.  If a single map panel is updated for any reason, the effective date for that community is updated.  For example, the current effective date for the City of Los Angeles is December 21, 2018, meaning that at least one map panel in Los Angeles was updated then.

FIRM ages

Figure 1.  Number of 532 California communities with a river study by year.  New Flood Insurance Studies (FISs) peaked in the late 1980s and early 1990s.  For the past decade, an average of 7-8 communities per year have received new studies.

On January 1, 2019, the Community Status Book listed 2012 as the average year of the current effective map for California’s 532 jurisdictions.  Most of these updates were small alterations, not formal re-analyses.  This information gives the perception that the modeling that supports the maps average just 6 years old.  The actual average date of the most recent FEMA modeling study underlying California FIRMs is 1993.

Flood-Risk Mapping Today

In 2009, FEMA developed a new plan to manage its inventory of flood maps, entitled Risk Mapping, Assessment, and Planning (Risk MAP).  The Risk MAP vision is for FEMA’s flood mapping program to become database-driven.  Additional meetings and mapping products mandated by the Risk MAP program add cost and time to complete a new study.  Since 2015 at least five new Risk MAP projects have not yet led to a final product (E. Curtis, written comm., May 4 2019).  What will it cost to upgrade the maps using the Risk MAP process?

In 2013, FEMA asked DWR to assist in developing a Mapping Master Plan (DWR 2013) to: (1) assess funding needs for Risk MAP, and (2) provide a road map for meeting the Risk MAP NVUE and deployment metrics.  The plan found that producing a Risk MAP product for each of California’s 532 communities would cost an estimated $445 million (inflation adjusted to 2019).  The Plan also showed that some communities in California may never again receive a new flood map funded by FEMA.

How does flood map age affect NFIP claims?

Over time, economic development and natural processes including climate change alter the hydrology and hydraulics of rivers and watersheds, changing flood risk.  Almost half of the FIRMs in California are based on studies over 20 years old.  This observation leads to several questions:

  • Do older flood maps lead to more flood damages and a greater proportion of flood insurance claims?
  • Do aging flood maps allow development or perhaps deter mitigation in ways that impact flood claims?

Accurate and up-to-date maps are needed to guide wise development on floodplains.

Conclusions and Recommendations

Several observations stand out from this analysis.

  • Less than 30,000 miles of California’s estimated 180,000 stream miles have been mapped by the National Flood Insurance Program (NFIP).
  • Less than 23% of California’s 30,000 NFIP mapped stream miles are designated as ‘Valid’ in FEMA’s asset management system.
  • Of the 22,138 California flood mapped stream miles not characterized as ‘Valid,’ FEMA currently has plans to study only a small fraction.
  • Most of California’s FIRMs are based on studies from the 1970s and early 1980s, when mapping and computing technology was significantly less accurate.
  • The conversion of paper FIRMs to digital format can give the public and policy makers false perceptions of map accuracy and flood risk.
  • The cost of updating all of California’s outdated FIRMs using the Risk MAP process ($445 million dollars) would be almost $2000 per current California NFIP policyholder (inflation adjusted to 2019).
  • Many California communities may never again receive a new flood study funded by FEMA.

The original mandate of NFIP was to update flood maps at least every five years.  In actuality, map updates are unusual and the nation’s inventory of flood maps has become “out-of-date, using poor quality data or methods and not taking account of changed conditions” (Horn 2018).

Flood maps continue to age faster than they are updated.  New mapping and map updates have become more expensive and time-consuming.  NFIP has run up a $36 billion structural deficit.  California can lead in using new technologies to quantify and communicate flood risk.  Several private companies already market models that assess flood risk throughout the US.  These models are arguably less accurate than a detailed site-specific model, but they calculate flood hazard as a continuous parameter, not just in or out of a 100-year line.  These risk-based models can better quantify and incorporate uncertainty.  Risk-based modeling also can easily and quickly be updated to reflect changing hydrologic, hydraulic, and climatic conditions over time.

California should consider making improvements to how flood risks are assessed, mapped, and updated.

Further Readings

California Department of Water Resources (DWR), 2013.  California Deployment and Mapping Master Plan (Draft). Prepared under Mapping Activity No. 3 executed in 2010 by Atkins.  Sacramento, CA: CA Department of Water Resources.

Congressional Budget Office (CBO), 2017.  “The National Flood Insurance Program: Financial Soundness and Affordability. Congressional Budget Office Report.  Washington D.C.: Congressional Budget Office.

FEMA, 2018a.  Community Status Book, FEMA Database.  The National Flood Insurance Program Community Status Book.  2018.

Horn, D.P.,  2018.  “National Flood Insurance Program: Selected Issues and Legislation in the 115th Congress. Report to Congress R45099.  Washington DC: Congressional Research Service.

Kelly, J.V.  2017.  FEMA Needs to Improve Management of Its Flood Mapping Programs. OIG Report OIG-17-110.  Washington D.C.: Office of the Inspector General, Department of Homeland Security.

Kathleen Schaefer is a PhD student in Civil Engineering at the University of California, Davis and a former FEMA administrator.  Nicholas Pinter is a Professor at the UC Davis Department of Earth and Planetary Sciences.


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