State of Bay Delta Science 2008

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CALFED

SCIENCE

PROGRAM

SUMMARY FORPOLICYMAKERS AND

THE PUBLIC

THE STATE OFBAY-DELTA SCIENCE

2008


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e State of Bay-Delta Science 2008

Summary for Policymakers and the PublicNovember 2007

CALFED Science Program

Editor in Chief: Michael Healey, PhD.

Editorial Board: Michael Deinger, PhD.

Richard Norgaard, PhD.

Managing Editor: Darcy Jones

Editor/Designer: Robert Ullrey, CSE.

CALFED Science Program

650 Capitol Mall, 5th oor

Sacramento, CA 95814

Technical support for this summary will be found in the full The State of Bay-Delta Science2008 to be released early in 2008.


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CALFED SCIENCE PROGRA M 3

Prefacee State of Bay-Delta Science 2008: Summary for Policymakers and the Public presents important newpolicy perspectives arising from recent advances in how scientists now understand the Bay-Delta eco-system.ese perspectives both challenge the way we once understood the Delta, and our policies formanaging it. We describe these advances more completely in the full, State of Bay-Delta Science 2008report, scheduled for publication in early 2008. e summary report synthesizes our current scienticunderstanding of the Bay-Delta ecosystem in easily assessable, nontechnical terms.

e amount of scientic information about issues in the Bay-Delta has increased dramatically in recentyears, stimulated by creation of the CALFED Bay-Delta Program in 2000. Research promoted by CAL-

FED and other science agencies has increased our understanding of how the Bay-Delta functions and haschallenged some long-held beliefs about the Bay-Delta. Problems of water management, environmentalprotection, and levee integrity continue to intensif y, however, and are being further complicated by cli-mate change and sea level rise. Several high level planning and evaluation processes are underway to ndsolutions to these problems, including Delta Vision, the Bay-Delta Conservation Plan, and the Delta RiskManagement Strategy.ese processes all depend heavily on scientic understanding of the Bay-Delta.Policymakers and the public need to be well informed about current scientic understanding of the Bay-Delta ecosystem to be able to assess alternative policies and to make sound decisions about water andenvironmental management.is summary provides an overview of our scientic understanding to helpguide policymakers in nding solutions.e CALFED Science Program stawill update and revise thefull State of Bay-Delta Science report from time to time as new information becomes available.

Michael HealeyLead Scientist, CALFED Bay-Delta ProgramSacramento, CA, January 2008.


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4 THE STATE OF BAYDELTA SCIENCE, 2008: SUMMARY


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Introduction1

e environmental resources of the San Francis-co Bay and Sacramento-San Joaquin Delta have

long contributed to the states diverse society andits prosperous economy. However, in pursuit ofwellbeing and prosperity, over the past 150 years,Californians have dramatically changed the Deltasgeography, hydrology, and ecology. Today, the Bay-Delta is degraded and its capacity for providing allthe environmental and societal benets the publicdemands (viable populations of desired species,

wild habitats for recreation and solace, land for ag-riculture, and the conveyance of reliable and high-quality freshwater) continues to decline.2

As the Delta has changed, science has played an in-creasingly important role, contributing to the waypeople perceive and respond to problems. As ourscience of the Bay-Delta has progressed, our under-standing has improved. Our comprehension of howthe Delta functions is today quite dierent from thatof a few decades ago. We now know that change isconstant, that it is neither possible nor desirable tofreeze the Delta at any point in time, that the chal-lenges of water and environmental management areinextricably intertwined, and that the capacity ofthe Delta to deliver environmental and water sup-ply expectations is likely at a limit.

e problems of the Bay-Delta are broad based anddo not easilyt within traditional discipline-basedproblem solving. Looking to the future, we nowno longer consider earthquake-induced levee fail-ures and Katrina-style ooding to be science c-tion. Realistic views of the future include dramatic

changes such as accelerated sea-level rise, changes inthe availability of fresh water, and continued species

1 Technical support for this summary will be found in thefull State of Bay-Delta Science 2008 report, to be released earlyin 2008.

2 Explored further in chapters 1 and 2 of the full State ofBay-Delta Science 2008 report, in preparation.

invasions. e scientic community is grappling with the implications of these complex problemsfor designing research projects, interacting with andlearning from other scientists, and communicatingtheir ndings to policymakers.

e establishment of the CALFED Bay-Delta Pro-gram in 2000 helped to address the problems of wa-ter quality, reliability, levee integrity, and ecosystemrestoration in the Delta and its tributaries. Sincethen, CALFED-supported science has helped toclarify the extent and seriousness of the problems inthe Delta, and has identied a spectrum of potentialsolutions. ese solutions and how to implementthem are now under debate as part of the Delta Vi-sion process.

e New Science of the

Bay-Delta

Routine scientic monitoring of the Bay-Delta be-gan more than three decades ago under the auspicesof the US Geological Survey and the InteragencyEcological Program. e long-term data sets pro-

vided by this monitoring, combined with recentproblem-focused research and analysis stimulatedby CALFED has greatly increased our understand-ing of the Bay-Delta system. Nevertheless, muchstill remains to be learned, and changing back-ground conditions (e.g., climate change, popula-tion growth, species invasions) are continuallychallenging our ability to predict the future fromthe past. Problems that policymakers must addressare increasing in complexity, and solutions call fornew forms of collaboration among scientists from

dierent disciplines. Helping in this collaboration,the CALFED Science Program has acted to expandand facilitate communication among scientists, and

between scientists and policymakers through itsjournal San Francisco Estuary and Watershed Science,newsleers like Science News, model-development,

biennial science conferences, and many workshops.CALFED has helped scientists to look beyond their


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specic disciplines and see the Delta as a whole laying the important groundwork for the Delta

Vision,3 Delta Risk Management Strategy,4 and theBay Delta Conservation Plan.5

e result of all this scienti

c activity has been anew perspective of the Delta, and recognition that

3 For more information on the Delta Vision, visit www.deltavison.ca.gov.

4 For more information on the Delta Risk ManagementStrategy, visit www.drms.ca.gov.

5 For more information on the Bay-Delta Conservation Plan,visit www.resources.ca.gov/bdcp/.

the environmental services provided by the Deltawill continue to degrade with some disappearing ifwe continue our current policies for water and environmental management. Our policy frameworkof the past has served California well, but our en-

hanced understanding of the Delta shows that weneed new policies if the Delta is to continue to pro-vide the range of services that Californians demand.is summary of the State of Science for the Bay-Del-ta System is framed around our new perspectivesarising from recent Delta science. It highlights themost important changes in how we now understandthe Delta and provides the principal policy implica-tions (see Table 1).

Table 1. New perspectives on the Delta derived from recent science

Perspective One:e Delta is a continually changing ecosystem. Uncontrolled drivers ofchange (e.g., population growth, changing climate, land subsidence, seismicity) mean that theDelta of the future will be very dierent from the Delta of today.

Perspective Two: Because the Delta is continually changing, we cannot predict all theimportant consequences of management solutions. e best solutions will be robust butprovisional, and will need to be responsive and adaptive to future changes.

Perspective Three: It is neither possible nor desirable to freeze the structure of the Delta in itspresent, or any other form. Strengthening of levees is only one element of a sustainable solution

and is not applicable everywhere.

Perspective Four:e problems of water and environmental management are interlinked.Piecemeal solutions will not work. Science, knowledge, and management methods all need to

be strongly integrated.

Perspective Five:e capacity of the Sacramento-San Joaquin water system to deliver human,economic, and environmental services is likely at its limit. To fulll more of one water usingservice we must accept less of another.

Perspective Six: Goodscience provides a reliable knowledge base for decision-making, but for

complex environmental problems, even as we learn from science, new areas of uncertainty arise.

Perspective Seven:Accelerated climate change means that species conservation is becomingmore than a local habitat problem. Conservation approaches need to include a broad range ofchoices other than habitat protection.
http://localhost/Users/emery/Desktop/NSF/MustReadPDFs/www.deltavison.ca.govhttp://localhost/Users/emery/Desktop/NSF/MustReadPDFs/www.deltavison.ca.govhttp://drms.ca.gov/http://drms.ca.gov/http://resources.ca.gov/bdcp/http://resources.ca.gov/bdcp/http://resources.ca.gov/bdcp/http://drms.ca.gov/http://localhost/Users/emery/Desktop/NSF/MustReadPDFs/www.deltavison.ca.govhttp://localhost/Users/emery/Desktop/NSF/MustReadPDFs/www.deltavison.ca.gov


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Perspective One

e Delta is a continually changing ecosystem.Uncontrolled drivers of change (population

growth, changing climate, land subsidence,seismicity) mean that the Delta of the future willbe very dierent from the Delta of today.

Despite the fact that change is what characterizesthe Bay-Delta, our policies and even some of our sci-ence have oen assumed that the Delta of the future

would be much the same as the Delta of today. Agrowing body of science, however, shows that large-scale changes are commonplace in systems likethe Bay-Delta. Powerful external forces are drivingchange in the Bay-Delta. A more realistic viewpointis that change is inevitable, and is necessary for theproper function of the system. Estuaries and deltasare dynamic, constantly changing ecosystems. epresent Delta formed when the sea level rose fol-lowing the last ice age, which ended 10,000 BCE.

As the rivers of the central valley carved away at thefringing mountains, the Delta approached its pre-colonial geometry about 5,000 BCE. In the past 150

years Californians have imposed rapid changes on

the Delta creating islands and channels where there

had been marsh and tidal creeks, changing freshwa-ter ows and sedimentation paerns, dischargingchemical wastes, and introducing new species. israpid change continues today with human popula-tions increasing, land uses and associated discharg-

es changing, species from other regions invading,native species struggling with new challenges, theclimate warming, and the sea level rising.6

Continual environmental change must be accom-modated in any program to sustain valued species.Instead of seeking some constant, optimal condi-tions, sustainable management of the Deltas eco-system will rely on habitats that go through repeat-ed or uncertain cycles of change. Broadly speaking,

we understand that our native organisms evolved

in a variable environment and are beer adapted tothe large temporal and spatial variations more char-acteristic of Californias natural landscapes than tothe static conditions provided in heavily engineeredseings.

e muting of natural habitat rhythms is not theonly inuence to which Bay-Delta organisms mustrespond. A rising sea level implies that the location

6 Explored further in chapters 1 to 4 of the full State ofBay-Delta Science 2008 report, in preparation.

100

75

150

125

50

25

1850 1900 1910 1920 1930 1940 1950 1960 1970 1980 19901860 1870 1880 1890

Number of Invasive Species

Asian clamCorbiculauminea

arrives (1945)

overbite clam Corbulaamurensis arrives

(1986)

striped bassintroduced

(1879)

Figure 1.e estimated number of invasive species in the San Francisco Estuary from 1850 to 1995.(Adapted from Cohen, A. N., and J. T. Carlton, Accelerating Invasion Rate in a Highly Invaded Estu-ary, Science 279 (1998): 555-558.)


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of certain habitat types that we typically think ofas xed will change. Our system of land and watermanagement as a whole must be able to respond tosea level rise, which could be 3 feet or more overthe next century. From a scientic perspective,

changing background conditions means that ourmeasurements of the Bay-Delta system will neverconverge toward any normal values. Furthermore,as environmental change continues, the problem ascientist starts out to address may change into a newproblem for which hard won measurements andanalyses of the past may no longer be relevant. Forexample, the invasion of the overbite clam in SuisunBay changed the structure of the food web, makinghistoric understanding of food web dynamics lessrelevant to emerging conservation problems. As

California warms, and precipitation in the moun-tains changes from snow to rain, as sea level rises,and water quality constraints continue to evolve,many of todays water-supply problems may be

barely addressed before they are subsumed by thenext challenge. Science needs a nite period to un-derstand any natural process or trend, usually sever-al years for environmental problems. For example,precipitation paerns vary from year to year anddecade to decade. Several years of data are requiredfor the scientist to understand local hydrodynam-ics and water supplies. In times of sporadic change,science may be hard pressed to understand what ishappening well enough to inform policy. A strongerinfrastructure and rmer support for science willhelp narrow this gap in capacity.7

One of the main contributions of science to discus-sions of the future Delta has been precisely this re-alization that neither the undisturbed past, nor anarmored current condition can resist the continu-

ally evolving conditions and problems in the Delta.We now have a much clearer picture of how quicklythe system is changing, the direction of change, andhow uncertainties about future change limits rmstatements about ecological cause and eect ormanagement outcomes.


For science, this means improving our capacity tomonitor and evaluate change. For policy, it meansidentifying and implementing policies that are bothrobust to change yet exible and adaptable. 8

Perspective Two

Because the Delta is continually changing, wecannot predict all the important consequencesof management solutions. e best solutions

will be robust but provisional, and will need tobe responsive and adaptive to future changes.

e desire for permanent, or at least very long term,

solutions is commonplace in environmental andengineering designs. No one wants to repair a bro-ken system repeatedly. CALFEDs Ecosystem Res-toration Program is unique in its emphasis on usingphysical and ecological processes to help rebuildsustainable ecosystems that would produce the ser-

vices we desired (e.g., viable species populations,particular habitat types) yet with lile requiredmaintenance. Recent science in the Delta, however,has led to the perspective that continual environ-mental change is itself a key to sustaining valuedaquatic species. is means that any managementplan for the Delta must retain or restore exibilityand variability if key species, processes, and servicesare to be maintained. e desire for permanent so-lutions has pervaded other elements of CALFED,

but this is changing. Levees were once viewed aspermanent bulwarks against ood, but we now rec-ognize that levees are only one tool in the manage-ment ofood ows and that some levees should bedesigned to fail or be overtopped. In the past, we

designed water supplies for urban and agriculturalto be stable and reliable, but now we recognize that

8 Explored further in chapters 4, 6, and 7 of the full Stateof Bay-Delta Science 2008 report, in preparation.


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both supply and quality change with time, so thatreliability derives from the capacity for adaptation.9

In the face of pressures from growing human popu-lations, from aging levees, from degrading land sur-

faces, and from climate change and sea-level rise, wecan only expect that solutions that seem reliable to-day will become unreliable in the future. Our abilityto predict those challenges is unlikely to improveenough to make permanent decisions possible anytime soon. ese challenges limit our ability tomanage and control the Delta ecosystem.ey evenlimit our ability to monitor and identify changes.Under these circumstances, no single once-and-for-all solution for Delta problems can realistically beexpected. Rather, water and environmental man-

agement designs that will be most cost-eectiveand most likely to succeed will be practical, robustto anticipated changes, yet capable of adapting.eneed for adaptability recognizes that all solutionsare temporary; procedures and diverse options foradaptation need to be built in. To satisfy these needs

we should formally establish adaptive managementprocedures and strategies within agency policies.10

As we acknowledge the temporary nature of solu-tions, we increasingly recognize that the best poli-

cies are enabling instead of prescriptive. To increasepotential for learning and likelihood of success, themost valued policies will be those that allow a di-

versity of responses and can evolve as conditionschange. Since future conditions are uncertain, sur-prise is inevitable, and engaging a variety of policysolutions can help to spread the risk.



Perspectiveree

It is neither possible nor desirable to freezethe structure of the Delta in its present, or any

other form. Strengthening of levees is only oneelement of a sustainable solution and is notapplicable everywhere.

e Deltas levees grew with agricultural develop-ment of the vast marshlands, meandering channels,tidal sloughs, and muddy islands that existed beforethe Gold Rush. Laborers rst raised the low natu-ral levees that surrounded Delta islands by hand,then by dredging sands and silts from channels.eresulting levees are haphazardly engineered, withheavy mineral sediments commonly siing on topof less stable peat. Despite the levees structural

weakness, they dene the Deltas geography, waterchannels, land uses, habitats, ood ows, and tidalpaerns.11

Until recently, we believed that stable levees werethe foundation of a sustainable Delta. We viewedlevee stability as absolutely necessary for water-sup-ply reliability, a crucial determinant of water quality,

and the protector of the Deltas ecosystems and ag-riculture. Meanwhile, exposure of the islands peatsoils to air, re, wind, and compaction, has resultedin the ground surface in many Delta islands sub-siding as much as 25 to 32 below the water levelof adjacent channels. e levees themselves haveaged and weakened, breaking regularly, despite thedevelopment of massive ood control systems up-stream. Channelization of tidal and riverine ows

by the levees has created articial salinity and mix-ing conditions that favor invasive species over na-

tive species.12




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10 TH E STATE OF BAYDELTA SCIENCE, 2008: SUMMARY

Recent analyses of levees and levee risk show thatthe likelihood of levees failing in the future are high,that levees are limiting our options for ecosystemrestoration, and are a weak link in the States waterand ood management system. Maintaining them

in their current form would be very costly and dif-cult, even if historical conditions continued. ButDelta conditions are changing in ways that heightenthe risks posed by our dependence on levees. elevees may be shaered in an earthquake, face in-creasing pressure from oods and rising sea level,and continue to weaken with age and land subsid-ence. Decision-makers increasingly recognize thatthe present levee system is not a dependable foun-dation for the future Delta. Given the mountingpressure on the levees, it is likely that future levee

failures will be multiple, ooding many islands,posing a severe risk to human life, and disabling theStates water system for months or possibly years.8

For these reasons, sustainable policies for manag-ing the Delta need to discard any remaining beliefthat we can strengthen levees enough everywhereto protect Delta lands and infrastructure into thefuture.e use of levees are just one of several waysof managing and maintaining critical landscapes inthe Delta, such as human uses and selements. In

some places, we should strengthen levees to provide reliable long-term protection for existing ur-ban development, or critical water supply channels,for example. In other places, levees could hamperecosystem restoration, eective ood management,

and other long-term goals. We need more holisticand comprehensive approaches to oods, emer-gency preparedness, and habitat restoration. Leveesand other hard engineered works will be part of thesolution, but using multiple approaches is likely toprovide more reliable and sustainable solutions tothe wide range of Delta problems. We should designmuch of the Deltas levees and land use to absorboccasional overtopping and failure. Land use poli-cies reecting such realities as subsidence, the ris-ing sea level, and the impracticality of assuring the

same level ofood protection everywhere are morerealistic than policies built solely on levee strength.Urban planning that acknowledges the risks, directsdevelopment from the most ood prone areas, andpromotes ood-safe construction is also part of asustainable solution.

Perspective Four

e problems of water and environmentalmanagement are interlinked. Piecemealsolutions will not work. Science, knowledge, andmanagement methods all need to be stronglyintegrated.

Western science has succeeded by breaking prob-lems into their constituent parts and conductingresearch to understand each part in isolation. Weexpect to understand the whole from understand-

ing the parts. e success of this approach in boththe physical sciences and engineering has even in-uenced the way we organized governmental agen-cies: hydrologists in water agencies, sheries biolo-gists in sheries agencies, etc. But the success of thereductionist approach in the physical sciences hasnot been paralleled in the environmental sciences.

A clear understanding of the whole has not emerged

Figure 2. A sunny day levee failure in June2004 results in the ooding of Upper JonesTract.


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CA LFED SCIENCE PROGRA M 11

from our understanding of the parts. Environmen-tal problems can arise and persist because of weak-nesses in the application of reductionist science toproblems in complex ecological systems.

Science in the Delta has used both reductionist andinterdisciplinary methods and research. To addressthe complex issues of the Bay-Delta, scientists fromdierent backgrounds have learned to share infor-mation and to look at problems in new ways, muchas numerous disciplines including physicists, ecolo-gists, and economists have come together in thestudy of climate change. CALFEDs research fund-ing across agencies to bring scientists from manydisciplines together with resource managers in

workshops to address particular topics mirrors the

most recent developments in science worldwide.An example of this integration is the research con-ducted to understand the Pelagic Organism Decline(POD). Researchers designed a multifaceted con-ceptual model that has connected declines in pe-lagic organisms to a spectrum of interlinked causesranging from water exports to agricultural practices,and from invasive species to sediment transport.e interlinking of Delta science on water supply,

water quality, and ecosystem health with land uses,ood management, and levee engineering are heav-ily inuencing planning for a sustainable vision ofthe Delta.13

Much environmental science in the Bay-Deltacomes from the long-term monitoring programsconducted by the Interagency Ecological Program,the San Francisco Estuary Institute, and otherprograms and agencies. is monitoring has pro-

vided the data for nearly all the crucial analyses oftrends and variability in the estuarys ecosystems.

However, the monitoring has been based on theassumption that simply measuring the numbers oforganisms, or the quality of water will allow properecosystem management and restoration. We nowrealize that to understand changes in the abundanceand distribution of particular species, we must also


understand the dynamics of their predators andprey. To understand the impact of water qualityon species and the ecosystem, we must also under-stand the processes that distribute chemicals in theenvironment and through the food chain. Further-

more, entire groups of organisms, important physi-cal parameters, and important contaminants havegone unmonitored. Recent scientic successes haveshown that a mixture of multidisciplinary monitor-ing, modeling, and eld and laboratory studies isneeded to synthesize, track, and understand chang-es in the Delta. Aempts to understand the PODhave shown both the strengths and the weaknessesof existing databases and monitoring. As sciencehas integrated more aspects of the system into itsanalyses, it is becoming clear that to understand the

Delta, we must mobilize the full range of tools andmethods of science ranging from ecotoxicology togenetic ngerprinting, from biotelemetry to sys-tems modeling. 14

Problems of the future will be as multifaceted andcomplicated as those we face today. Research sup-porting management, as well as management itself,

will be most successful if they embrace this com-plexity in search of eective and adaptive solutions.Our limited ability to predict the results of manage-ment actions in the Delta reects our inexperience

with linking the methods from the many separatedisciplines that contribute to Delta science. Build-ing these linkages remains an important area forscientic progress in the future. Collaboration that

brings together researchers and managers in inter-agency research and workshops to build linkageshas been very inuential in advancing Delta scienceand management. Bay-Delta science also provides amodel for scientic management eorts elsewhere.

However, we can do much more to encourage andstrengthen the integration of disciplines and the in-tegration of science into management.

14 Explored further in chapter 4 of the full State of Bay-Delta Science 2008 report, in preparation.


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Perspective Five

e capacity of the Sacramento-San Joaquinwater system to deliver human, economic, and

environmental services is likely at its limit. Tofulll more of one water using service we mustaccept less of another.

Since European selement, Californias streamshave been tapped to meet ever-increasing humandemand for water. In the Twentieth Century, fed-eral and state water projects increased storage andconveyance capacities resulting in spectacular pros-perity for the state. Now, California has grown to apopulation of 36 million with an economy that isthe 7th largest in the world, largely on the strengthof its large-scale integrated approach to water man-agement. However, opportunities for increasingsupply to satisfy growing demand are becominglimited, and environmental problems are creating agrowing need to reallocate water to the ecosystem.

As Californias population grows, increasing urbanwater needs will have to be met mainly by improv-

ing water management instead of by developingnew supplies within the Sacramento-San Joaquinsystem.15

e transition from a belief in growth through wa-

ter development to growth by working within waterlimits began during the last quarter of the 20th cen-tury as Californians reached real limits and becameincreasingly aware of the environmental impacts of

water development on habitat loss, species declines,and water pollution. Severe droughts in 1976-1977and 1987-1992 brought home the fact that water isprecious while also showing the possibilities for wa-ter conservation. We have replaced our old way ofthinking about water as owing wasted to the sea

with the recognition that every drop of water ow-

ing in a river to the sea contributes to valuable eco-system functionality. Today, individual water con-sumption is less than it was 30 years ago, and waterplanners are oen more concerned with water reli-ability and quality than with increasing supply.16

Frequently, conicts between water limits and the water needed to meet societal and environmentalgoals come to a head in the Delta. Priorities havechanged in recent years, and water deliveries are nowtimed to meet environmental functionality as well

as the needs of water users. Proposals for improvingwater supply reliability increasingly recognize thatreliability will depend on having multiple supply,storage, and conveyance choices. Waste products ofthe human economy are also discharged into water,and the far-reaching impacts of certain wastes are

becoming increasingly clear. Stimulated by concernover the impact of selenium and mercury on shand birds in the Bay-Delta, science has shown thecomplex environmental and ecological impacts of

these contaminants. Selenium is released during oilrening and from soil irrigated along the west sideof the San Joaquin Valley. Irrigation drainage waters



Figure 3. Delta Water Balance showing inowsand outows during an average water year, inthousand acre-feet. (Source, California Depart-ment of Water Resources. Status and Trends of Delta-Suisun Services. By URS Corporation,Sacramento, 2007: 18.)


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hypotheses that linked outow to sh populations(see Figure 4, previous page).

We now understand that policies must accommo-date these underlying uncertainties. An example

of such an accommodation is the multibarrier ap-proach for drinking water-quality maintenance,where in the face of uncertain sources, threats,and needs we develop multiple, redundant safe-guards on water quality. Integrated approaches to

water-supply reliability that draw on several dier-ent sources and conveyances to mitigate the un-certainties and risks of each are another exampleof accommodating inherent uncertainties througha diversity of management options. Similarly, ex-ible approaches need to be developed for ecosystem

restoration and levee integrity. Adaptive experi-mentation to maximize learning opportunities anda precautionary approach to management decisions

would help to avoid the overuse of resources thathas characterized past water management.

Perspective Seven

Accelerated climate change means that species

conservation is becoming less of a local habitatproblem. Conservation approaches need toinclude a broad range of choices other thanhabitat protection.

e recovery of species listed as threatened or en-dangered is the main driver of todays science andconservation planning in the Delta. Although theproblems of the Bay-Delta are ecosystem levelproblems, we see them revealed through the disap-

pearance of individual species or habitats, and it isthese losses that capture our aention. When CAL-FED began, listed races of Chinook salmon werethe primary focus of research and management.Shortly aer all parties signed the Record Of De-cision (ROD), the POD emerged, and aer 2004,

began to drive science and water management deci-sions. As a listed and an included POD species, the

Delta smelt has received a great deal of aention.Although the causes for the decline of Delta smeltremain uncertain, (they are quite likely multiplecauses including export pumping, toxic substanc-es, and food web changes), there is also a growing

recognition that global warming may make the fu-ture Delta intolerable to Delta smelt and other val-ued species, undermining local aempts to protectthem. Even as science increases our ability to man-age the changes that we can control, it also showsus the implications of such uncontrollable changesas climate. In the face of such externally imposedchallenges to Delta species, conservation becomesmore than a local problem of habitat management.Instead, it engages wider questions such as whether

we should establish refuge populations of smelt, or

other species where the physical environment re-mains suitable; whether cryopreservation of DNA,or maintenance of captive populations need to bepart of our conservation tool kit; and whether arti-cial genetic modication to change the environmen-tal tolerance of a species should be aempted.21

Invasion of the Delta by non-native species is alsoan issue of great concern that is linked to native spe-cies loss. We know, for example that the invasiveoverbite clam appropriates most of the primary pro-duction in Suisun Bay, starving the food web lead-ing to Delta smelt. We also know that the invasion

21 Explored further in chapter 4 of the full State of Bay-Delta Science 2008 report, in preparation.

Figure 5. As the climate changes and watertemperatures warm, the Delta may no longer

be able to support the imperiled Delta smelt.


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of Brazilian waterweed has enhanced the habitat oflargemouth bass and sunsh to the disadvantage ofnative species. Under the United Nations conven-tion on biodiversity, invasive species are a primarythreat to biodiversity, and signatory nations, though

the United States is not one, must develop plans forpreventing and managing the adverse impacts ofspecies invasions. In our changing global environ-ment, we may need to adopt a broader perspectiveon species introductions. e Bay-Delta is alreadyone of the most invaded estuaries in the world, andfurther invasions are almost certain to occur. As cli-mate changes and the Delta becomes inhospitableto native species, it may nevertheless provide a ref-uge for species from warmer habitats that are them-selves facing intolerable local conditions. Relocat-

ing species for conservation purposes may becomeas important as protecting local habitats.

e kinds of environmental changes expected forthe Bay-Delta in the near future call for a rethink-ing of both policy and management of native andalien species. Critical habitat, as required under theEndangered Species Act, may no longer be wherea species lives today, but somewhere further north,at a higher elevation, or in an unexpected seing.Conservation policy will have to be open to explor-ing many ways to preserve biodiversity.

e Way Forward

ese new scientic perspectives on the Bay-Del-ta and its environmental challenges highlight thegrowth in scientic understanding of the Delta andof ecosystem management that has occurred duringthe past decades. ese perspectives highlight the

impending globally and locally driven changes tothe Bay-Delta to which policy must respond. Glob-ally, climate change is expected to raise sea levelthree feet or more over the next century, changeprecipitation and storm paerns, and raise localtemperatures several degrees. Locally, populationgrowth, land subsidence, earthquakes, and speciesinvasions will drive ecological change and increase

risks of ooding. Scientically, we now recognizethat change and uncertainty are essential charac-teristics of our local ecosystem dynamics. We oenmanage natural resources under an assumption ofpermanence, that the future will be like the pres-

ent, and that management should aim for the op-timum condition. is is not an achievable goal.Future infrastructure, both for management and forscience, needs to be robust but exible, inclusiveand adaptive, resilient and sustainable in the faceof change. Uncertainty is pervasive and althoughabsolute solutions are unlikely to be found, science

will continue to be a main source of information forpolicymaking. Building and maintaining the scien-tic infrastructure to help meet future challenges isessential to any sustainable way forward.

Scientic input to water and environmental man-agement has a long history in California. CALFEDhas brought science more fully into the policy pro-cesses. e Science Program has introduced a newand forward-looking approach that integrates the

broad spectrum of scientic and technical adviceneeded to address the highly complex problemsof today. Tools used by the Science Program haveincluded interdisciplinary workshops, support forresearch that cuts across agency mandates, and in-tegration of science with the practical knowledge ofresource managers. ese tools have strengthenedour understanding of challenges in the Delta, as

well as the options available to address them. WhenCALFED began, expectations were that we couldresolve ecosystem issues through modest changesin water management and minimal reallocation of

water.e POD has now forced water managementagencies to consider signicant water reallocations.Initially, CALFED considered Delta stabilization

and levee integrity a primary goal: now the Delta Visioning process is imagining a mixture of leveeprotection in some areas, and alternative land andow management options in others. e evolutionof policy from an emphasis on engineered solutionsto an emphasis on engineered natural designs that

work with natural processes reects advances in


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ecosystem science, new environmental conditions,and changing societal expectations.

Within the above context, the way forward appearsto include several extensions of the goals and strate-

gies that CALFED began with. Generally, scienceprovides three important elements to the debateabout resource management problems: (1) objec-tive information about the system and how it be-haves; (2) models of physical and biological systemsthat illustrate how dierent policies might aect theproblems; and (3) a shared, formalized languageand a forum that permits informed debate.e wayforward for CALFED science is to strengthen itscapacity to make these contributions (see Table 2,previous page).

Science as a source of objectiveinformation about the system andits behavior

ere are systemic weaknesses in the science infra-structure that supports water and environmentalmanagement in the Bay-Delta. One of these weak-nesses is a lack of consistent support for targetedresearch on key unknowns in the Bay-Delta eco-

system. CALFED Science has begun a competitiveprogram of research grants for critical research, buthas lacked the secure funding to carry this programinto the future. Given the pace of change, futuremanagement decisions will be increasingly depen-dent on scientic synthesis, insight, and advice fromscientists with hands-on experience in the Delta.

Assured support for policy relevant research is thebest way to ensure that information and advice willbe available when needed.

Since its inception, CALFED has striven to en-hance and extend observation networks, includingdevelopment of the Comprehensive Monitoring

Assessment and Research Program (CMARP): un-fortunately, CMARP has yet to be implemented.More recently, the Science Program has been work-ing with the implementing agencies to develop per-formance indicators for their CALFED initiatives:

but this eort is still at a conceptual stage. We alsosee a desperate need to monitor existing and futureproject performance objectively. More comprehen-sive monitoring would provide the raw materials fortimely decisions about project direction and con-

tribute to improved physical and biological mod-els of the Delta. e CALFED Science Programis working to develop a feasible, more integratedframework for monitoring across implementingagencies.

e ROD species that adaptive managementshould be the tool for integrating science more fullyinto management. CALFED agencies have madeconsiderable progress in implementing adaptivemanagement, but weaknesses remain. Support for

monitoring and assessment, which is central to theadaptive process, is intermient, as is the use ofprospective analysis to explore policy alternatives.CALFED science has the capacity to help agen-cies make further progress in formally establishingadaptive management.

CALFED has a strong Bay-Delta focus, but is ad-dressing a set of problems that exist in variousguises throughout California. Nationally, there areseveral major projects focusing on water and envi-

ronmental conicts, for example the Upper Missis-sippi, Great Lakes, Everglades, and Columbia Basinprojects. ese projects would benet from state-

wide and national networks of information sharing.CALFED is regarded as a successful model in sci-ence coordination and integration and could be aleader in establishing such a network.

Science as a set of tools forevaluating system responses to

policy alternatives

e complexity and interlinked character of theBay-Delta system and all its most vexing problemscall for a new generation of system-scale, cross-dis-ciplinary models. CALFED has supported severalsteps toward developing such tools including an am-

bitious aempt to develop interlinked species con-


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Table 2. Future directions for CALFED science

Scientific contribution to

environmental problem

solving

Strengthening CALFEDs capacity

Objective information aboutthe system and its behavior

1. Secure long-term support for CALFED Proposed SolicitationPackage program at about $20 million annually to support researchthat targets key unknowns

2. Support development and implementation of a comprehensivestrategy for monitoring and assessment that takes advantage ofrapidly emerging technology

3. Integrate adaptive experimentation and adaptive managementinto design and implementation of Delta Vision strategic plan and

Bay Delta Conservation Plan so that program performance can beassessed in a timely manner

4. Integrate the CALFED Bay-Delta Program more fully intostatewide and national networks of information sharing andinstrumentation to support ecosystem management and restoration

Evaluation of systemresponses to policy options

1. Support development of cross-disciplinary, systemwide modelsof physical and biological processes in the Delta (e.g., US GeologicalSurveys CASCaDE project)

2. Establish CALFED Science as a focus for high level, integrativemodeling of system response (e.g., through elaboration of DeltaRegional Ecosystem Restoration Implementation Plan models,linkage to regional databases, etc.)

3. Strengthen the capacity for objective policy analysis through useof these models in conjunction with adaptive management andperformance measures

Formalized and informed

debate about science andpolicy for environmentaland water management

1. Strengthen existing tools (e.g., workshops, discussion papers) for

engaging science and policy

2. Strengthen capacity to translate science into policy relevantknowledge

3. Strengthen public outreach about science issues to inform thebroader debate about science and policy


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ceptual models, and various eorts to link physicalmodels with ecosystem responses. Such modelingneeds to be strongly supported so that policymak-ers can be informed by mature scientic models ofDelta processes. Forecasting the consequences of

policy choices will always be uncertain, but modelsprovide the most objective means of bringing com-plex ecosystem data into policy analysis.

At present, there is lile capacity in CALFED, orthe implementing agencies, for cross-disciplinarymodeling of ecosystem behavior. For the future,CALFED science should serve as a node or catalystfor the development of integrative models. As partof the Science Program, such models would havelegitimacy and would provide another avenue for

coordination and communication among diverseinterests in the Delta. Policy analysis is becomingincreasingly reliant on quantitative risk analysisand numerical analysis. For the CALFED ScienceProgram to remain relevant, it will need to build itscapacity to apply these tools and to connect them in

ways that provide a complete picture of ecosystemresponse.

Science as a facilitator of informed

policy debate

Finally, CALFED needs to expand and strengthenits ability to bring science into policy debates. No-tably, as the Delta Vision Blue Ribbon Task Forcecompletes its new vision, and following its debateand implementation, it will be all the more impor-tant that independent scientic information andmethods are near the center of decision-making.

CALFED Science uses a variety of communication

and outreach tools for scientists these include theon-line journal San Francisco Estuary and WatershedSciences , and the biannual science conference; forpolicymakers, workshops and discussion papers;and for the public through newsleers like the Sci-ence News, as well as public lectures. ese avenuesneed to be strengthened and expanded in the future

to ensure a smooth and eective ow of scienticinformation to policymakers and other interests.

Science is crucial to any policy debate and objec-tive, peer-reviewed science provides the most reli-able basis for policy decisions. Making reliable sci-ence available to policy debates has always been a

weak link in the science-policy process. e ScienceProgram has a good track record of facilitating thisinformation ow, but it needs to be sustained andimproved.

CALFED and the CALFED Science Program werecreated in recognition of a need for stronger coordi-nation, integration, and communication to addressproblems of water supply, water quality, levee in-

tegrity, and ecosystem performance. CALFED sci-ence has had considerable success facilitating theseprocesses within the scientic community and hasalso stimulated new science to address importantgaps in knowledge. As a result, our understandingof Delta processes has improved and policymakersare beer informed. ese science-based activities

will be even more important in the future.


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For more information:

Contact the CALFED Science Program

650 Capitol Mall, 5th Floor, Sacramento, CA 95814

(916) 445-5511

http://calwater.ca.gov/science

CALFEDSCIENCE

PROGRAM
http://calwater.ca.gov/sciencehttp://calwater.ca.gov/science

Documents

State of Bay Delta Science 2008