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Climate and Urban WaterProviders in Arizona

An Analysis of VulnerabilityPerceptions and Climate

Information Use

CLIMAS• Institute for the Study of Planet Earth

Climate Assessment for the SouthwestClimate Assessment for the Southwest

Rebecca H. Carter and

Barbara J. Morehouse

CLIMAS Report Series CL1-03

Rebecca H. CarterInstitute for the Study of Planet Earth

Barbara J. MorehouseInstitute for the Study of Planet Earth

Published byThe Climate Assessment Project for the Southwest (CLIMAS)Institute for the Study of Planet EarthThe University of ArizonaTucson, Arizona

CLIMAS Report Series CL 1-03July 2003

Climate and Urban WaterProviders in Arizona

An Analysis of VulnerabilityPerceptions and ClimateInformation Use

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Climate and Urban Water Providers in Arizona

Table of Contents

Abstract ................................................................................................................................................... 2

1. Introduction ...................................................................................................................................... 2

1.1. Project Overview..................................................................................................................................... 21.2. Climate Assessment for the Southwest Project......................................................................................... 31.3. Regional Climate Assessments ................................................................................................................. 3

2. Background ....................................................................................................................................... 4

3. Research Methods ........................................................................................................................ 6

3.1. Questionnaire ......................................................................................................................................... 73.2. Personal Interviews ................................................................................................................................. 83.3 Confidentiality ......................................................................................................................................... 8

4. The Research Context ................................................................................................................ 9

4.1. Geographical Context ............................................................................................................................. 94.2. Water, Population Growth, and Climate in the Southwest .................................................................... 114.3. Policy and Political Context .................................................................................................................. 13

5. Results .............................................................................................................................................. 14

5.1 Most Disruptive Types of Weather and Climate ..................................................................................... 145.2 Size DOESN’T Matter .......................................................................................................................... 185.3 Population Growth ................................................................................................................................ 185.4 Water Sources, Delivery, and Distribution ............................................................................................. 215.5 Short-term Service vs. Long-term Sustainability ..................................................................................... 27

6. Implications .................................................................................................................................... 28

6.1 Low Concern About Climate-related Disruptions .................................................................................. 286.2 High Provider Confidence in Their Systems .......................................................................................... 296.3 High Variability Among Water Systems and Locations ........................................................................... 296.4 Current Use of and Interest in Climate Information .............................................................................. 316.5 Strategies for Enhancing the Use of Climate Information....................................................................... 32

7. Conclusions .................................................................................................................................... 32

Endnotes ................................................................................................................................................ 33

References ........................................................................................................................................... 34

Appendix A: Survey ......................................................................................................................... 37

Appendix B: Interview Questions ............................................................................................ 41

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Abstract

Among the many stressors affecting urban water supply and demand in the U.S. Southwest is climatic variability,particularly prolonged drought. At shorter time scales, weather events such as floods, high winds, unusually hotweather, and electrical storms may also affect water production and delivery systems. At the same time, climaticvariability is but one of a number of factors affecting urban water management in the region. Research into thesensitivity and vulnerability of urban water systems in Arizona reveals that managers are more concerned aboutfactors such as population growth projections, economic trends, and revenue flows. Reliance on groundwater re-sources in many cases obscures recognition of any direct impact of precipitation on water supply. Some systemsrely on multiple water sources and/or interconnections with other providers to address the risk that they may atsome point not be able to serve customers’ needs. In other cases, water providers, especially many who rely on fos-sil groundwater that receives little recharge, do not perceive any link between climate and risk to their water sup-ply. Given the low level of perceived climate risk among many providers interviewed for this study, it would seemunlikely that climate information would be needed. However, pockets of sensitivity and vulnerability to climaticimpacts do exist in the four study areas covered in this study. Findings indicate that efforts to provide climate in-formation may best be directed toward these particular providers. Whether the strong perceptions of invulnerabil-ity held by water managers hold up under a severe sustained drought remains to be tested.

1. Introduction

1.1. Project OverviewThe Southwest is one of the most rapidly growing ar-eas of the United States and also one of the most arid.Water managers must balance the needs of exponen-tially expanding populations with the physical realityof limited water supplies. Weather- and climate-relatedevents, such as unusually hot weather, prolongeddrought, or flood events, frequently place additionalstress to urban systems. One way that water managersmay prepare for and cope with such events is throughexpanding their use of climate information and fore-casts. However, the climate research community lackssufficient knowledge about the use of information bylocal water managers, exactly which types of weatherand climate events managers find most difficult tocontend with, and what their specific informationneeds are. Water managers, on the other hand, mayhave limited knowledge of what products are available,where to access them, and how to apply them to theirdecision-making processes.

This analysis seeks to answer some of these questions.It provides insight into the ways that climate- andweather-related factors affect urban water systems inthe southwestern United States and whether and howwater providers use climate information in coping withweather- and climate-related events and situations. Theresearch identifies factors that affect the perceived andreported adaptability and vulnerability of water sys-tems to climatic fluctuations and links these issues tokey organizational factors within each water system.

The study also includes a summary of providers’ re-ported current level of use of climatic forecasting prod-ucts, as well as comments and suggestions from thewater providers regarding potential improvements tothe relevance and clarity of forecasts.

The study reflects several hypotheses that were gener-ated through a background literature review and pre-liminary interviews and tested through the survey pro-cess. These hypotheses included:

• Given that the study areas include some of thedriest and hottest locations in the United States,drought and high temperatures cause the mostsignificant strains of water systems in southernArizona.

• Smaller water systems serving fewer people aremore sensitive to climatic variations than largersystems, due to a lack of capital to install bufferssuch a storage space and additional/deeper wells.

• The rate of population growth plays a critical rolein determining how vulnerable a system is to cli-matic variability. However, the exact nature of thisrole is uncertain, since smaller, stable systems maynot have the capital to put in buffers against cli-matic disruptions, but systems in fast-growing ar-eas might not be able to keep up with growth.

• Systems relying on only one water source are morevulnerable to drought due to less redundancy intheir water supplies and less flexibility in their sys-

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tems. Hence, the greater the number of watersources a system can access, the less vulnerable toclimatic fluctuations it is.

• Water systems dependent exclusively on ground-water resources are essentially invulnerable toshort-term climatic variability, but are at risk fromlong-term climate shifts towards drier weather.

The study revealed that a complex web of factors de-termine the resilience of systems, including water sys-tem size, number of water sources, degree of relianceon groundwater, and rate of population growth; butthat previously unconsidered features, such as theavailability of backup systems for pumps, depth to wa-ter table, and type of water system management alsoplay important roles. This report will show that whilesome providers are adept at coping with the types ofclimatic situations that they currently encounter, theirpotential resiliency in the face of unusual climatic condi-tions may be less robust than they anticipate. Althoughthere was a lack of clear correlation between self-assessedvulnerability and natural or human-created factors,water providers may not be as well buffered against cli-matic extremes as they may think, particularly oncewater supplies are stretched thinner by populationgrowth. When examining individual water systems,we were often able to delineate variables that deter-mine that system’s vulnerability or resiliency. Systemsthat were highly vulnerable tended to have one ormore of the following factors:

• Only one water source, which could be at risk dueto contamination or overdraft,

• An organizational structure that made it difficultto obtain sufficient funds for infrastructure main-tenance and improvement,

• Location in rapidly growing areas where powersystems and other infrastructure were alreadystressed by demand,

• Location in newly developed areas that had not yetdeveloped adequate infrastructure.

On the other hand, systems that demonstrate resil-iency had one or more of these characteristics:

• Plan for possible future events, rather than relyingsolely on actual past events,

• Have several layers of redundancy in their systems,

• Have detailed drought and flood mitigation plans,

• Have backup systems.

The findings reinforce the importance of examining wa-ter systems as unique entities, and the need for systemmanagers to be thoroughly involved in any future effortsto better buffer systems against climatic variability. Amore detailed discussion of the hypotheses and thestudy findings is presented in the Results section.

1.2. Climate Assessment for the Southwest ProjectThe Climate Assessment for the Southwest (CLIMAS)Project at the University of Arizona is an integrated as-sessment of the impacts of climatic variability in thesouthwestern United States. The project draws uponthe expertise of an interdisciplinary team of hydrolo-gists, climatologists and social scientists to holisticallyexamine the physical, economic, and social ramifica-tions of potential climate change. Funded by a grantfrom the National Oceanic and AtmosphericAdministration’s Office of Global Programs, theproject seeks to provide decision makers and stake-holders with better access to and understanding of cli-mate forecasting products, and also to provide thosewho produce climate predictions with insight into thetypes and forms of information most useful to users.

More information about the CLIMAS Urban WaterStudy, and the place of this report within it, may befound on our website, http://www.ispe.arizona.edu/climas/research/.

1.3. Regional Climate AssessmentsThis study provides an example of the importance oftaking a regional approach to the study of climate im-pacts. It is at the regional and local levels that climateactually affects people, and thus the impacts of globaland hemispheric weather and climate phenomena canbest be studied at this level. By undertaking a more in-depth investigation of a smaller area, regional assess-ments provide opportunities for comparing and con-trasting results between locations and sectors, therebyincreasing the overall knowledge base and ensuringthat measures enacted to mitigate the effects of cli-matic variability are appropriate at the communitylevel. A regional approach also allows assessment ofthe impacts of climate change to effectively integratestakeholders.

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Specific constraints, concerns, and challenges faced bywater providers, and ways that forecasting productscan be designed to increase the efficiency and resiliencyof individual water systems, can best be understood atthe regional level. One of the primary challenges ofwater system management is ensuring that the physicalrealities of water supply and demand are effectively in-tegrated within a region’s unique environmental, so-cial, and legal milieu.

2. Background

A large and growing body of literature exists regardingclimate impacts on water resources, as evidenced bythe online bibliography maintained by the Pacific In-stitute (http://www.pacinst.org/global.html#bib).Much of the literature reflects the fact that research onthe impacts of climate on water resources has beendirected toward determining the effects of long-termclimate change. Due to limited ability to downscalethe results produced by general circulation models, ef-forts to identify the impacts of climate change at re-gional or finer scales of resolution have not achieveddesired levels of accuracy. However, consensus hasformed around the notion that arid and semiarid areascould be among the most seriously affected by antici-pated climatic changes and that relatively smallchanges in temperature and precipitation, combinedwith non-linear effects on evapotranspiration processesand soil moisture conditions, could result in relativelylarge changes in runoff in these regions (IPCC 1995).Regardless of what any future climate change maybring, CLIMAS takes a “no regrets” stance toward un-derstanding how water providers deal with current lev-els of climatic variability and in assessing what repeatsof past climatic extremes might mean to water re-sources and systems with both present and projectedpopulations, in order to better anticipate, prepare forand manage climate-related disruptions to water sys-tems.

The Intergovernmental Panel on Climate Change(IPCC) suggested that a focus on natural climate vari-ability and impacts at regional and local scales wouldenable researchers and decision makers to find ways toeffectively address climate-induced disparities betweenwater supply and demand in a context-specific manner(IPCC 1995). The ultimate goal of these efforts is toenable water managers to achieve standard perfor-mance criteria (reliability, safe yield, probable maxi-mum flood level, resilience and robustness) under a va-

riety of climatic conditions. According to the IPCC,sensitivity analysis and vulnerability analysis, combinedwith focused institutional analysis, are useful methodsfor contextualizing the impacts of natural climatic vari-ability and of greenhouse gas-induced climate change(IPCC 1995). The CLIMAS Urban Water Study is in-vestigating these three facets of urban water in theSouthwest.

The IPCC defines sensitivity as the “degree to which asystem will respond to a change in climatic conditions,for example the extent of change in ecosystem compo-sition, resulting from a given change in precipitationor temperature” (1995:5). A previous CLIMAS report(Carter et al. 2000) examined the sensitivity of urbanwater systems in five Arizona locations by investigatingthe past and potential future impacts of the worst 1-,5-, and 10-year droughts in the historical record in thecase study areas that are further examined in this re-port. The current study also includes questions aboutthe sensitivity of water systems that attempt to deter-mine the degree to which specific systems respond toweather and climate. An institutional analysis of Arizonawater laws and policies provided a contextual frameworkfor understanding climate impacts on urban water re-sources and summarized the legal framework withinwhich water managers must work when coping with cli-mate impacts (Carter and Morehouse 2001).

The current vulnerability analysis of urban water sys-tems thus constitutes the third component of study.The Panel defines vulnerability as “the extent to whichclimate change may damage or harm a system” (IPCC1995:5). This theme is reflected throughout thepresent study, with questions targeted toward deter-mining the vulnerability of water systems in order toexamine the extent to which weather and climate mayimpede their capacity to function (O’Connor et al.1999). Vulnerability analyses have contributed sub-stantially to enhanced understanding of the human di-mensions of climate variability and change (see, e.g.,Liverman 1999), and the present study is intended tomake similar contributions. Vulnerability analyses havealso aided in the development of methodologies for ef-fectively combining social science and natural scienceresearch through integrated assessments, including theCLIMAS project (see, e.g., Parson 1995, Easterling1997, Schneider 1997, and Rotmans and Dowlatabadi1998).

Because the extent of vulnerability depends not onlyon the sensitivity of water systems to normal climatic

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fluctuations, but also on their ability to cope with thenew climatic conditions, evaluation of adaptability isessential as well; therefore, many of the questions askedof water providers in this study are intended to assessthis factor. Adaptability is defined as the capacity of asystem to adjust to specified actual or projected condi-tions (IPCC 1995). Questions in the present study de-signed to elicit information about the adaptability ofwater systems focus on how practices, processes, orstructures could be adjusted to respond to past climac-tic fluctuations or a changing future climate.

The present report is to some extent modeled after asimilar study that O’Connor et al. (1999) carried outwith water managers in Pennsylvania’s SusquehannaRiver Basin. The report provided an important sourcefor contextualizing the Arizona findings through com-paring and contrasting survey results with those of aregion of the United States that is much more humidand has a greater abundance of surface water sources.As discussed in greater detail in the Research Methodssection of this report, this study replicates many of thequestions asked in the Susquehanna survey in order tofacilitate comparison across the two regions. Several ofthe same issues are considered by both the presentstudy and the Susquehanna study, and some findingsare similar; for instance, in neither case do smaller wa-ter systems appear to be more vulnerable to climaticfactors than larger ones. However, a comparison of thetwo studies reveals important differences as well. Forone, many of the water providers in the Susquehannastudy were in the process of shifting from surface waterto greater groundwater use in an effort to meet stricterSafe Drinking Water Act requirements; this processwas found to also reduce vulnerability to weather andclimatic fluctuations. In contrast, many water provid-ers in southeastern and central Arizona are taking theopposite approach of shifting from reliance on ground-water to greater use of surface water. In an effort to re-duce vulnerability to weather and climate, this strategyis seen as a mechanism for preserving groundwater re-sources until they are needed to address long-termdrought stresses.

Likewise, a survey of water resource managers in thePacific Northwest’s Columbia River Basin (Miles et al.2000), which was designed to identify perceptions ofclimate change, climate impacts on water resource op-erations, and use of climate information, provided ad-ditional insights useful to the present study. The resultsof that study revealed considerable potential for con-flicts among competing users such as irrigation, hydro-

power, municipal, navigational, recreational, environ-mental, and commercial interests. A relative lack ofreservoir storage capacity was identified as a contribut-ing factor to the various vulnerabilities articulated bythe respondents. The authors found that managementinertia and the lack of a centralized authority to coor-dinate all water resource uses impeded capacity toadapt to drought and to optimize water distribution.The report emphasized the importance of understand-ing the patterns and consequences of natural regionalclimate variability as a foundation for developing suffi-cient response capacity for responding to future cli-matic changes, which is identical to the philosophyunderlying the CLIMAS vulnerability analysis.

This type of analysis is particularly important in therapidly growing arid and semiarid areas of the South-west, where rainfall and temperatures in any given yearare rarely “average,” and climatic extremes are commonoccurrences. A review of the current state of knowledgeabout climate and climate processes in the Southwest(Sheppard et al. 1999) provided important back-ground information about climate variability in thestudy areas. Frederick stressed the need to take largeseasonal and annual variations into account when ana-lyzing climate impacts on water resources in theUnited States, noting, “The highest levels of use andthe lowest prices are often found in the more arid areasof the country” (Frederick 1995:17). Reflecting on re-search on U.S. river basins regarding the ratio of waterstorage to average annual water supply required tomaintain safe yield (roughly defined as a sustainablebalance between inflow/recharge and outflow/with-drawals), Frederick warns, “By this criterion, the pointof negative returns may already have been reached inthree major basins—the Lower Colorado, the UpperColorado, and the Rio Grande…” (Frederick 1995:17).Given some of the study areas’ increasing reliance onColorado River supplies to meet the needs of theirburgeoning populations, and their location in highlyvariable climatic regions, a better understanding of thecurrent and potential impacts of climate on water re-sources in arid areas such as the U.S. Southwest consti-tutes a key research area.

Given the reliance of the Phoenix and Tucson metro-politan areas on Colorado River water, the work of Nashand Gleick (1993), which focuses on the sensitivity ofwater flows and supply in the Colorado River Basin toclimate variability, provided valuable background in-formation. Likewise, Gleick and Chalecki’s (1999) re-port on the impacts of climate change on water re-

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sources in the Colorado and Sacramento-San JoaquinRiver Basins was informative. A report by Hendersonand Lord (1995) details the results of a gaming exercisedesigned to evaluate alternative institutional optionsavailable to water managers to cope with drought con-ditions as severe as those that occurred from approxi-mately 1579 to 1600 throughout the Colorado RiverBasin, providing insights into how water managersmight respond to the stresses of water shortages.Among the findings pertinent the present study, theplayer representing Arizona was successful in reducingthe state’s demand for consumptive use of Central Ari-zona Project (CAP) water delivered from the ColoradoRiver by 20 percent, while at the same time essentiallyeliminating drought-related water shortages. This wasaccomplished through interstate water marketing andbanking and selection of intrastate water managementrules (such as subsidizing CAP water use and enforcingsafe-yield policies).

Imbalance between renewable supplies and demandpose marked challenges to water managers in theSouthwest. Maddock and Hines (1995) observed thatrapid growth occurred in urban water use in theSouthwest between 1965 and 1990. During this time,public supply withdrawals and per capita consumptiongrew at about double the national rate. The authorsnoted that this rate of growth accelerated into the early1990s, although per capita consumption may have be-gun leveling off in some urban areas. Further, they ob-served that even before taking climate variability intoaccount, predictions have indicated that Las Vegas,Nevada would consume its entire Colorado River en-titlement in less than 15 years. Careful conservationand full use of its Colorado River entitlement notwith-standing, Las Vegas may see water supply deficits afterthe year 2025. Denver’s water supply is likewise antici-pated to be insufficient to meet demand by the year2020 (Riebsame 1997).

Specific to the urban water case studies examined inthis report, the Third Management Plans published bythe Arizona Department of Water Resources (ADWR)for the Phoenix, Tucson, and Santa Cruz Active Man-agement Areas (AMAs) were indispensable (ADWR1999a, 1999b, 1999c), as was a hydrographic surveyreport issued by the department for gaining a basic un-derstanding of water resources in the Sierra Vista area(ADWR 1991). The Third Management Plans, inparticular, provided a wealth of information aboutthe nature of water resource management in eacharea, in terms of both supply and demand, and listed

the water companies within the AMA boundaries bysize and location.

The CLIMAS Urban Water Study was further in-formed by an array of sources. A significant addition tothe climate and water resources literature was madethrough research carried out under the U.S. NationalClimate Assessment, which was mandated by Con-gress. Under the “Global Change Research Act of1990” (PL 101-606), the U.S. Global Change Re-search Project analyzed the effects of global change onnatural and human made systems and formulatedtrend projections for the next 25 to 100 years. TheJournal of the American Water Resources Association pub-lished two special issues devoted to research on the in-teractions among climate, hydrology and water re-source management (Vol. 35, No. 6, December 1999and Vol. 36, No. 2, April 2000; see also Gleick 2000).

Work by Lins and Stakiv (1998), which examines is-sues surrounding the management of water resourcesin the context of broad-scale climate change, provideda foundation for thinking about the impacts of naturalclimate variability in local settings. Miller’s analysis(1997) of the impacts of both natural climate variabil-ity and longer-term climate change on water in thewestern United States and Revelle and Waggoner’swork (1983) on anthropogenically induced climatechange on western water supplies provided a more re-gional focus for understanding the interactions be-tween climate, water resources, and society.

It is in this context that climate impacts of urban waterresources in Arizona must be considered. Yet althoughthe United States, including the Southwest, is nowpredominantly urban, relatively few studies of the im-pacts of climatic conditions on water resources havebeen done on urban water systems, particularly withregard to climate impacts on water demand (Boland1997). The CLIMAS Urban Water Study aims to helpfill that gap.

3. Research Methods

This report combined a written survey with a detailedinterview protocol to develop an in-depth assessmentof climate impacts and climate information use amongurban water providers in four areas of Arizona. Using acombination of structured and semi-structured ap-proaches allowed us to acquire important informationabout water providers’ perceptions. Perceptions are im-

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portant because, as this report will demonstrate, watermanagers tend to combine personal, subjective assess-ments of a situation and potential risks with more ob-jective types of evidence. While many of the questionsin the survey asked about verifiable, objective factors(the number and proportion of water sources, etc.),several of the key questions asked water providers torecall their responses to past events and to project whattheir responses might be to possible future conditions.Answers to these types of questions were tempered bythe amount of experience the interviewee had in man-aging the water system, their level and type of educa-tion in water management, the political and economiccontext of their water system, and their individualawareness of and interest in climate-related issues.

In the spring of 1999, we mailed surveys to 54 of the59 large water providers in four areas of southern Ari-zona, as identified by ADWR. (Those not interviewedincluded institutional or military water providers.)We received 28 responses, and follow-up interviews withthe 22 providers who were willing and able to meet wereconducted over the summer of the same year. An ex-ample of the survey is included in Appendix A; a sampleset of interview questions may be found in Appendix B.

Table 1 gives a breakdown of the numbers of waterproviders surveyed and interviewed in each study area.This sample of water providers allowed us to examine awide variety of water systems with differing watersources, population sizes, types of demand, and organi-zational structures.

Based on CLIMAS’s previous research endeavors and asimilar study of the Susquehanna River Basin in theU.S. mid-Atlantic region (O’Connor et al. 1999), ourquestionnaire and personal interview questions weredesigned to address the general hypotheses listed in theIntroduction and to address the fol-lowing specific climate-related impactson water systems: a) drought and hightemperatures would place the mostsignificant strains on normal water de-livery in Southeastern Arizona; b)smaller systems would be more sensi-tive to climatic variation due to a lackof capital to install buffers againstdrought and high temperatures, suchas greater storage space and deeper oradditional wells; c) population growthis an important determinant in theability of water systems to cope with

climatic variability; d) systems with multiple watersources may be expected to have greater redundancyand hence flexibility in coping with climate-relatedstress; and e) systems dependent on surface water wereexpected to be vulnerable to short-term climatic fluc-tuations, but systems that relied solely on groundwaterreserves would be less able to cope with longer-termdroughts.

Our aim was to expand our understanding of the sen-sitivity, adaptability, and vulnerability of urban watersystems in the U.S. Southwest (IPCC 1995). Sensi-tivity-related questions attempt to determine the de-gree to which the specific system responds to weatherand climate; those seeking information about theadaptability of water systems focus on how practices,processes, or structures might be adjusted to respondto past climactic fluctuations or a changing future cli-mate; and vulnerability-related questions examine theextent to which weather and climate may impede awater system’s capacity to function (O’Connor et al.1999).

3.1. QuestionnaireA four-page questionnaire was constructed andmailed to all water providers classified as “large” byADWR, meaning that they serve over 250 acre-feet(about 81 million gallons) of water per year. A sampleof the survey may be found in Appendix A. The sur-vey responses provide basic information regarding thesize of the population served, water resources utilized,infrastructure, and the job title and number of yearsin their current position of the person responding tothe survey. Parts of the survey were modeled after theSusquehanna River Basin study conducted by re-searchers at Pennsylvania State University (O’Connoret al. 1999), particularly those questions that askedrespondents to rate the likelihood that they would be

noitacoL noitacoL noitacoL noitacoL noitacoLsyevruS syevruS syevruS syevruS syevruS

deliaM deliaM deliaM deliaM deliaMsyevruS syevruS syevruS syevruS syevruSdenruteR denruteR denruteR denruteR denruteR

nruteR nruteR nruteR nruteR nruteRetaR etaR etaR etaR etaR

sweivretnI sweivretnI sweivretnI sweivretnI sweivretnI

AMAxineohP 03 31 %34 11

AMAnoscuT 61 01 %36 7

AMAzurCatnaS 4 3 %57 3

atsiVarreiS 4 2 %05 1

LATOT 45 82 %25 22

Table 1. Written Survey Return Rates and Interviews Conducted.

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CLIMAS

affected by various climactic events in the next fiveyears (Question 4) and to report the frequency withwhich they had suffered problems related to weatherand climate in the past decade (Question 5). TheSusquehanna group constructed this and other surveyquestions after extensive individual interviews and fo-cus group sessions with water managers in centralPennsylvania. This gave them ample opportunity totest the effectiveness of such questions and height-ened our confidence in using a similar approach forour research.

The survey results were recorded using the MicrosoftAccess relational database program; this program wasalso used to perform queries and analysis of the data.Where appropriate, Microsoft Excel was used to graphnumerical responses.

3.2. Personal InterviewsInterviews were requested from most respondents whoreturned surveys. Efforts were made to assure represen-tation of the spectrum of water supply sources, systemsizes and organizations, and broad geographical cover-age of service areas within the study sites. A sample ofthe interview questions is located in Appendix B.

The interview was presented as a follow-up to the sur-vey questions, and respondents were asked to meetwith the interviewer for approximately one hour. Theinterviews were a combination of structured and moreopen-ended questions. The same questions were askedof each respondent, using the same wording. Somequestions were added to later interviews to coverthemes that had surfaced repeatedly in earlier inter-views. Although efforts were made to cover all surveytopics at some point in the interview, several of themeetings became more free-flowing discussions of re-lated issues that the providers believed relevant to thediscussion. Thus not all questions were asked in the or-der indicated; instead, responses were sometimes rear-ranged during write-up to more closely conform to theinterview format and to facilitate the analysis. Theseinterview techniques allowed the researcher to obtain asufficiently standardized set of responses to allow forcomparisons among and identify key variables betweensystems, while at the same time allowing respondentsto provide examples and explanations of factors thatwere unique to their water systems.

The interview questions are divided into sections cov-ering internal policies and institutions; knowledge ofclimate and hydrologic variability in the past, present

and future; relevant policies and institutions; and cli-mate information use and needs.

Because the personal interviews were conducted in asemi-structured format, respondents were free to an-swer these questions in any way they saw fit, and therange of answers made quantifying the responses some-what difficult. In some cases, providers volunteered in-formation that they were not specifically asked about.Subsequent analysis of the data revealed instanceswhere several providers had mentioned similar con-cerns or observations, and thus these issues emerged asconcepts meriting analysis. However, since these find-ings were not uncovered by systematically questioningall providers specifically about them, we were unable todraw any firm conclusions as to whether or not thesefactors affect regional water systems generally. Manyproviders brought up issues that they believed to beimportant not only to their system, but to other sys-tems as well, and indicated how widespread they thinkthese issues are. This document occasionally uses termssuch as “a few” or “many” or “several” providers to re-port such information, which does not otherwise fitneatly into our analytical framework.

3.3 ConfidentialityAs would be expected regarding a scarce resource in arapidly growing area, water is a contentious issue incentral and southeastern Arizona. Access to ample andsecure water supplies to a large extent determines de-velopment and investment patterns in this region. Wa-ter providers must negotiate between their present cus-tomers’ needs and the potential for future growth, aswell as navigate through a complex web of local, state,and federal regulations dictating water quality andquantity standards. In order to assure that water pro-viders would be as candid as possible, the cover letterthat accompanied the mailed survey included a state-ment saying that providers would not be individuallyidentified, and that the results of the survey wouldonly be presented in aggregate form. Providers werealso assured before the interviews that their confidenti-ality would be maintained. Although analyzing therelative vulnerability of water systems according totheir location or other distinguishing characteristicsmight have provided interesting results, it would haveviolated the confidentiality agreement, and could haveraised issues that are beyond the scope of the CLIMASstudy. Therefore, while verbatim quotations from thesurveys and interviews have been used, informationthat could reveal the identity of individual providersand water systems has been omitted from this analysis.

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4. The Research Context

4.1. Geographical ContextFigure 1 illustrates the geographical areasconsidered in this report. The four areasinvestigated share a generally warm anddry climate, with a bimodal distributionof winter and summer rains. However, thelocations differ in terms of both naturalfeatures, such as elevation, average tem-peratures and seasonal rainfall amounts,and human-related features such as popu-lation size, growth rates, number of waterresources utilized, and primary economicactivities. Each area also has a unique wa-ter supply and demand profile, along withvarying institutional arrangements, whichhighlight the importance of taking a re-gional approach to understanding the po-tential impacts of climate change. Three ofthe study areas (Tucson, Santa Cruz, andSierra Vista) are located in the southeast-ern part of the state, while the fourth,Phoenix, is more centrally located.

Table 2 summarizes the spectrum of waterproviders in each of the study areas. Largewater providers are those who serve over250 acre-feet (about 81 million gallons peryear). This group included systems thatserve the vast majority of the populationof each area; indeed, small providers served less than 5percent of the residents of any study area. Only largeproviders were included in this study. Specific informa-tion about numbers and types of providers surveyedand interviewed for this study is included in the Re-search Methods section.

The urban centers of Phoenix, Tucson, and Nogales liewithin Active Management Areas (AMAs)—designatedby ADWR in 1980 as locations in need of more strin-gent groundwater use regulation to combat rapid de-clines in their aquifers. As such, these areas must worktoward the goal of “safe yield,” in which groundwaterwithdrawals do not exceed the amount replenished tothe aquifer on an annual basis.

Although some urban water supplies are used for in-dustrial purposes in the urban areas of Arizona, mostsystems are heavily dedicated to serving the area’s rap-idly growing population. As Table 3 illustrates, 26 ofthe 28 respondents indicated that more than half of

the water they supply goes to municipal/residential us-ers and 7 indicated that a full 100 percent of their us-ers are in this category.

The four study areas comprise different mixes of watersupplies and types of demand. The next section willhighlight the salient features and issues in each area.

Phoenix Active Management AreaThe Phoenix and Tucson AMAs were chosen becausethey include the largest water systems in the state, andalso encompass the fastest-growing urban water use ar-eas. Phoenix is the capital of Arizona and its most eco-nomically important area. It is also the largest popula-tion center, with more than twice the population ofthe Tucson AMA.

The Phoenix AMA is made up of communities of vari-ous sizes and divergent interests, along with extensiveagricultural areas and several Indian reservations. Mu-nicipal water needs accounted for 49 percent of total

Figure 1. CLIMAS Urban Water Providers Study Areas.

noitacoLlatoT

sredivorPllamS

sredivorPegraL

sredivorP

AMAxineohP 741 511 23

AMAnoscuT 151 721 91

AMAzurCatnaS 41 01 4

atsiVarreiS 7 3 4

LATOT 913 552 95

Table 2. Summary of Water Providers.

10

CLIMAS

water demand in 1995; this figure is expected to rise to61 percent by 2025 (ADWR 1999a). There are a totalof 147 water providers regulated under the Depart-ment of Water Resources’ municipal conservation pro-gram. Of those, 32 large municipal providers serve 82percent of total demand in the Phoenix AMA, whilelarge untreated providers1 meet 17 percent of demand.Small municipal providers account for 1 percent of to-tal demand. In this AMA, large providers serve 98 per-cent of the population, while small providers serve 1percent, and 1 percent is served by unregulated wells.The large providers consist of 12 municipal providers,which serve 93 percent of the population, and 18 pri-vate providers, serving 6 percent of the municipalpopulation. The municipal providers have an averagegallons per capita per day (gpcd) rate of 230, while therate for private providers is 312 gpcd.

In addition to having the largest population of thestudy areas considered, the Phoenix AMA is endowedwith the widest variety of water resources available foruse. Some Phoenix AMA providers are able to utilizeup to four different water sources: groundwater, sur-face water via the Salt River Project (SRP) system,Colorado River water delivered through the CentralArizona Project (CAP) canal, and substantial amountsof treated effluent.

Water management is a contentious issue in the AMA.Some areas are experiencing rapidly dropping watertables, while other locations are waterlogged due to re-charge efforts or being located down gradient from re-turn flows. Although some areas of the AMA have ac-cess to up to four different water sources, includingSRP and CAP supplies, other areas are logistically un-

likely to ever access these resources, and thusmust rely solely on groundwater and effluentsupplies. Access to SRP and CAP water is de-termined primarily by location within theAMA, and also by a provider’s ability to buildthe treatment plants necessary to utilize thesewater sources. Although long-standing rightsdetermine the basic allotments of these watersources, there is some room for negotiation forgreater or lesser amounts of water based onpopulation growth and the expansion of treat-ment and recharge facilities.

Private and municipal water systems differ intheir access to water resources. Most privateproviders serve only groundwater, with a mere11 percent of this sector’s total water supplies

coming from surface water. Municipal providers, onthe other hand, usually have access to several differentwater sources. Some large municipal water companiesthat make up the urban core of the Phoenix AMA haveaccess to all four water sources. For example, the Cityof Phoenix is the largest municipal water provider,meeting the water demand of 45 percent of the AMA’spopulation, and has access to groundwater, SRP andCAP supplies, and effluent. Renewable supplies (non-groundwater sources such as effluent and river water,i.e. SRP and CAP) account for 93 percent of the Cityof Phoenix’s water supplies (ADWR 1999a).

The value of a more fine-grained study of individualwater providers is highlighted by the fact that 30 per-cent of the water providers in the Phoenix AMA utilizeonly groundwater, and 23 percent employ groundwa-ter and one other water source. These providers mayhave more in common with water providers in theother three study areas, where the vast majority of pro-viders have access only to groundwater, than withother providers in the Phoenix AMA. This was the casewith 8 out of 10 water providers in the Tucson AMA,and all providers in the Santa Cruz AMA and in theSierra Vista area.

Tucson Active Management AreaThe Tucson AMA, which encompasses the secondlargest metropolitan area of the state, presents quite adifferent water supply and demand profile. Municipalwater demand accounted for 66 percent of total de-mand in 1995 and is expected to comprise 80 percentof demand by 2025 (ADWR 1999b). Of the 151 totalwater providers in the AMA, 127 are small municipalproviders; however, these small providers meet only 4

lairtsudnI lairtsudnI lairtsudnI lairtsudnI lairtsudnI/lapicinuM /lapicinuM /lapicinuM /lapicinuM /lapicinuMlaitnediseR laitnediseR laitnediseR laitnediseR laitnediseR

*rehtO *rehtO *rehtO *rehtO *rehtO

sresufotnecrep0 9 0 02

sresufotnecrep01-1 9 0 4



sresufotnecrep001 0 7 0

Table 3. Number and Percentage of Users in Different WaterSectors.

*Other types of users include commercial, lost and unaccounted for,agriculture, urban irrigation, government, and construction.

11


percent of total demand. Of the 19 large providers, 5are municipal providers, 11 are privately owned watercompanies, and 3 are institutional providers (whichwere not included in the present study). Large provid-ers meet the water needs of 96 percent of the AMA’spopulation. Unlike the Phoenix AMA, which has sev-eral large municipal providers, the Tucson AMA isdominated by Tucson Water, the municipal providerfor the City of Tucson, which serves 76 percent of totalwater demand. Municipal providers as a whole serve92 percent of the AMA’s population, while large pri-vate water companies serve 6 percent of the popula-tion. Gallons per capita per day rates in the TucsonAMA tend to be lower than those in the PhoenixAMA, with the average for both municipal and privatewater companies being around 172 gpcd (ADWR1999b).

Tucson was long the largest city in the United States tosubsist solely on groundwater, but this situation haschanged. CAP water, the only surface water available,is scheduled to supply 63 percent of the area by 2025,initially through groundwater recharge2 and eventuallythrough direct use. Full use of these additional watersupplies is necessary to meet the demands of the area’srapidly growing population. The city’s direct use ofCAP water is expected to expand as treatment plantsare built in the coming decades. However, as in thePhoenix AMA, different areas within the AMA facecontrary water management challenges. Water tablesare rising in the northwestern portion of the AMA,and falling in the southern regions, due to the north-west trending topography; thus the northwest benefitsfrom recharge being undertaken in areas to the south.At the same time, the northwestern area has far easieraccess to CAP supplies due to its proximity to theCAP Canal than do other areas such as the south andsoutheast, where rapid population growth is alreadyunderway.

Santa Cruz Active Management AreaThe Santa Cruz AMA, where the cities of Nogales,Tubac, and Rio Rico are located, was chosen in partbecause its location along the U.S.-Mexico border en-compasses important international water issues(Morehouse et al. 2000) and also because its hydro-logical structure and water supply situation differ sig-nificantly from the other study areas. This AMA is de-pendent on effluent that is generated in Mexico but istreated in the United States at the Nogales Interna-tional Wastewater Treatment Plant. The population ofSanta Cruz County was estimated to be 39,590 in

2001 (U.S. Census bureau 2002), making it by far theleast populous of the areas studied. It is also the leastwealthy area studied, with a median household incomefor Santa Cruz County of $29,710, compared with$40,558 for Arizona as a whole and $45,358 forMaricopa County, where Phoenix is located (U.S.Census Bureau 2002). This has implications for itsability to build and maintain infrastructure that couldbe crucial in coping with increased climatic variability.The Santa Cruz AMA has 4 large water providers, 3 ofwhich are private water companies, and 10 small pro-viders. The average rate is 189 gpcd, although the ratevaries considerably among providers.

Sierra Vista SubwatershedThe fourth study site, the city of Sierra Vista, is locatednear an important and endangered riparian area, theSan Pedro River. The human population of the area isexpanding rapidly, but this location is not subject tothe same stringent level of regulation as are the AMAsof Phoenix, Tucson, and Santa Cruz. A group knownas the San Pedro Partnership currently handles watermanagement in the San Pedro watershed, where SierraVista is located. The group’s goal is to establish an al-ternative management structure in order to avoid be-ing declared an Active Management Area. ADWR isvery much involved in this process.

Sierra Vista is adjacent to a major military installation,Fort Huachuca Army Base, which also has substantialwater needs that are unlikely to decrease over the nextseveral decades. In addition to the military base, thereare four main water providers, the largest of which has6,400 customers. The Sierra Vista area also has hun-dreds of private wells operated by widely dispersedhomeowners throughout the area. While the water useof these individual well owners falls below the levelthat would subject them to ADWR regulation, the im-pact of such large numbers of small wells upon theaquifer is not fully understood.

4.2. Water, Population Growth, and Climate in theSouthwestAccording to the survey responses, water availabilityand population growth are the overriding natural andsocial factors in water management in the Southwest.Water managers were given a list of possible factorsthat determine water supply and demand budgets andthat limit the number of customers served. In eachcase, they were asked to select the five most importantand rate them from 1 to 5, with 1 being the most im-portant. The numbers along the x-axis in Figures 2 and

12

CLIMAS

3 indicate the total number of points awarded to eachpossible response. If single factor had garnered 5 pointsfrom each of the 28 survey respondents, the totalwould have been 140 points.

As Figure 2 shows, water availability ranked as themost important factor in determining the number ofcustomers that a water system could serve. Water islimited in the study areas not only by relative aridity,but also by regulations and policies (discussed ingreater detail in a later section of this report). Ground-water pumping is regulated in the Phoenix, Tucson,and Nogales urban areas due to the fact that they arelocated in legislatively defined AMAs. Surface water isavailable in some areas of Phoenix via the CAP canal,which delivers Colorado River water, and through theSRP system, which brings water from the Salt andVerde Rivers. Colorado River water is also delivered toTucson via the CAP canal. (Surface water is not avail-able to Nogales or Sierra Vista.) However, water man-agers are allotted set amounts of surface water via thesedelivery systems and must negotiate to purchase addi-tional amounts if demand exceeds supply.

As indicated in Figure 3, population projections are byfar the most significant determinant of most waterproviders’ supply and demand budgets.3 Most waterproviders interviewed said that they assume that bothwater supply and per capita water use will stay thesame; thus population projections multiplied by usagerates is the primary factor they consider when budget-ing and in planning for infrastructure and capital im-provement projects. As one provider noted, “We don’treally do long-term planning; we just update thingsbased on usage rates.”

Water budgeting is closely interwoven with, and insome cases indistinguishable from, fiscal budgeting. Asone provider said, “We do financial budgets annuallyand estimate demand only for financial reasons, not re-ally anything having to do with supply.” When askedto describe what they would consider the ideal climaticconditions from a water management standpoint,some managers indicated cool, wet weather that wouldkeep demand low and supply high; but several otherssaid that they preferred hot, dry weather because highdemand ensures a robust revenue stream. A preferencefor predictable and fairly moderate weather, with nosudden extremes, was mentioned repeatedly.

Groundwater levels ranked as the third most impor-tant factor in determining water budgets, indicating

Figure 2. Factors Limiting Number of Customers Served.

0 10 20 30 40 50 60 70 80

Other – Permitting

Personal preference

Limited economic returns

Water rights

Limited capital

Limited infrastructure

Water availability

Total number of points per resonse (140 possible)

Figure 3. Factors Determining Water Supply and DemandBudgets.

0 20 40 60 80 100 120

Agricultural acreage

Streamflow data

Transitory population

Climate forecasts

Effluent reuse rate

Current and past climate data

Economic development plans

CAP availability

Urban development plans

Groundwater table

Current population

Population projections

Total number of points per resonse (140 possible)

13


that many water providers are aware of the conditionof their aquifers and reflecting the focus of current sus-tainable water-use initiatives in the state. Urban andeconomic development plans were also relatively im-portant determinants. CAP availability ranked fifthoverall, but was the third most important factor in thePhoenix AMA, probably due to the area’s greater reli-ance on this water resource. It is likely that SRP wateravailability would have proven to be important in thePhoenix AMA if this option had been listed, althoughno providers included them in the category of “other.”Current and past climate data, climate forecasts,streamflow predictions, transitory population, the ef-fluent reuse rate, and changes in agricultural acreagewere ranked as relatively unimportant. The relativeunimportance of climatic data or forecasts was borneout by the interview results: none of the water provid-ers interviewed employed a staff person specifically re-sponsible for climate or forecast analysis.

Another way of examining the results of this questionis to combine the factors that can be clearly linked toclimatic factors, including CAP availability, groundwa-ter level, climate data and forecasts, and streamflowdata, and compare them to the sum of the factors thatare more human-related, such as population projec-tions, current population, urban development plans,economic development plans, effluent reuse rate, tran-sitory population, and changes in agricultural acreage.The aggregate number of points for climatically linkedfactors is 134, while the human-related figure wouldbe 301. After dividing by the total number of possiblepoints in each category, a resultant ratio of .19 for cli-matically linked factors versus .31 for human-relatedvariables can be created. This ratio supports the con-clusion that human-related water supply factors areconsidered more important than natural supply factorsby water providers as a whole.

4.3. Policy and Political ContextUrban water managers in the Southwest operatewithin a complex web of international, federal, state,county, and municipal laws and policies. The policyanalysis of the CLIMAS Urban Water Study (Carterand Morehouse 2001) addresses these issues ingreater detail. Although the present study includedonly a few questions that explicitly focused uponpolicy issues, water managers mentioned them re-peatedly in many different contexts. This illustratesthe importance of considering the policy context inunderstanding the vulnerability of urban water sys-tems to climatic variability.

Interviewees were asked, “What changes in laws, poli-cies and procedures would you consider most useful inenabling your organization to better deal with climatestresses on your system?” Only 13 of the 21 water pro-viders asked this question had any specific answers, butthose who did respond revealed interesting perspectives.

Two responses dealt specifically with the complex webof policy and economic issues that hinder the ability ofwater providers to cope with drought. One providersaid that ADWR’s groundwater management require-ments for dealing with drought need greater flexibility.Another provider noted the lack of more localized in-formation regarding the likely impacts of drought ontheir area: “DWR hasn’t shown us any data about howlong or serious a drought we could endure before therewere problems. DWR doesn’t seem to have accurate oradequate information about our situation here…”Water quality issues related to the EPA’s recent tighten-ing of Safe Drinking Water Act (SDWA) requirementswere also mentioned by four providers as managementissues likely to become more problematic in times ofclimatic stress, and as populations continue to expand.It has long been assumed that if drought conditionsdecreased surface water availability, groundwater re-serves could be called upon to make up for any short-ages. However, regardless of climatic conditions,groundwater contamination due to arsenic, nitrates,fluoride and heavy metals is a problem in some areas.If groundwater quality does not meet new SDWA re-quirements, as is particularly likely during drought pe-riods, severe supply problems could result. One pro-vider suggested that the Arizona Department ofEnvironmental Quality should modify their waterquality requirements during drought periods.

In addition to ADWR regulation of water systemswithin the AMAs, the governing body of the munici-pality where the system is located regulates municipalwater providers in Arizona. Non-municipal water ser-vices, on the other hand, are governed by the ArizonaCorporation Commission (ACC), as provided in theArizona State Constitution (Arizona Revised Statutes40). The ACC has as its first priority regulating therates charged by these providers and limits the abilityof water providers to pass on the costs of water conser-vation to consumers, or to raise rates to encourageconservation. In our interviews, few providers men-tioned the ACC as being problematic, and one evencommented on how much the ACC has improved overthe past few years. However, when asked whether ra-tioning water or raising water rates were potential

14

CLIMAS

means of encouraging water conservation in droughtsituations, private providers frequently noted thatACC regulations would make those actions impossible.One provider noted that, “It would be helpful to havethe legal ability to cut back on the water pressure whenwe need to, and also to be allowed to pass on the costof any additional water we’d have to bring in to copewith drought.” Municipal providers would have moreflexibility in raising prices in times of water scarcity toencourage conservation. Some providers said that thisoption was included in or being considered for theirdrought plan, but none reported having actually en-acted higher rates based on climatic factors.

5. Results

5.1 Most Disruptive Types of Weather and ClimateIt might seem that in a region with limited water sup-plies and a rapidly growing population, drought andsimilar long-term climatic changes could be the mostsevere threat to the effective functioning of urban wa-ter systems. Thus we hypothesized that:

Given that the study areas include some of thedriest and hottest locations in the UnitedStates, drought and high temperatures causethe most significant strains of water systems insouthern Arizona.

To test this hypothesis, we used survey and interviewquestions to examine how vulnerable overall water sys-tems are to weather- and climate-related disruptions,and to identify which types of climate or weather-relatedoccurrences are most disruptive. Our findings, how-ever, did not wholly support this hypothesis.

In general, water managers believe themselves to berelatively impervious to climate-related impacts in thenear term. Providers cited myriad other factors as be-ing more important to the management of the watersystems, including population growth, the actions ofstate agencies, decisions made by town councils, cus-tomers, and stockholders, and regulations. Despite thegeneral lack of concern about climate impacts and therelatively low level of concern about weather-relatedimpacts, however, all providers were able to cite ex-amples of ways such factors did indeed affect the op-erations of their systems, as this section will discuss.

Figure 4 shows the results of a survey question thatasked respondents to rate on a scale of one to five the

likelihood that the daily operations of their water sys-tem would suffer climate-related impacts within thenext five years, with one being “very unlikely” and fivebeing “very likely.”4 The results of this question dis-prove one of our hypotheses, that drought and hightemperatures would be the most significant disruptionsto water systems. Instead, electrical storms were con-sidered more likely to cause disruptions than were hightemperatures; high winds ranked third, above drought.

Table 4 provides more detail about managers’ expecta-tions of future weather and climate-related disruptionsby examining the distribution of high and low re-sponses to the previous survey question. Respondentsclearly expect greater disruptions due to shorter-termweather-related factors, such as electrical storms andhigh winds that can disable pumps, than they do fromswings in natural climate variability, such as drought orextended periods of increased precipitation. All respon-dents indicated that capacity to cope with droughtstress is built into their systems. However, analysis ofour findings suggests the importance of distinguishingbetween the amount of water available for use (i.e.stored in an aquifer) and the portion of that water thatcan actually be delivered. Even systems with amplesupplies of water, but that lack the secure infrastruc-ture to deliver that water on a consistent basis, mayface short-term difficulties that would appear to besimilar to those of systems actually lacking sufficientwater supplies.

Figure 4. Likelihood of Climate-related Impacts Within theNext Five Years (Average of 27 responses).

0 1 2 3 4

Low temperatures

Increased precipitation

Surface water contamination

Flash floods

Drought

High winds

High temperatures

Electrical storms

Veryunlikely

Equallylikely andunlikely

Unlikely Likely

15


Table 5 illustrates the distributionof answers to survey question 6,which asked water providers aboutthe specific problems that theirsystems have encountered in thepast5. Respondents were asked tocircle the number from 1 to 5 thatcorresponded with the number oftimes their system had been af-fected, with 1 indicating “never,”and 5 meaning “10 or more timesper decade.”

The interviews provided greaterspecificity into climate andweather impacts on water systems.For example, respondents saidduring interviews that delayed orscanty summer rains may have amuch more significant impact onwater systems than dry winters,despite the fact that winter rainsand mountain snows are far moreimportant in hydrologic terms forreplenishing aquifers and ensuringadequate stream flows (seeSheppard et al. 2000). Notably,drought was considered a fairlylikely consequence by respondentsin Sierra Vista and the Santa CruzAMA, reflecting the more climate-sensitive nature of the aquifers inthese areas. Impacts from ex-tremely low temperatures werealso viewed as more likely in SantaCruz AMA.

Electrical Storms and High WindsIt is not surprising that electricalstorms and high winds were iden-tified as the most significantsources of weather-related disrup-tions; these conditions may be analmost daily occurrence duringthe early July through late Augustmonsoon period, and may also oc-cur in conjunction with storms atother times of the year. Althoughthe monsoon season may accountfor up to one-half of an area’s totalannual rainfall in just two months,local convectional activity gener-

*Ten of the 28 providers actually use some form of surface water, including CAP,SRP, or other surface water.

Electrical Storms

Extremely high temperatures

High winds

Extremely low temperatures

Drought

Flash floods

Surface water contamination

Increased precipitation

1

4

3

7

12

10*

11

12

8

5

5

1

3

0

0

5

Climatic ConditionNumber of “very

unlikely” (1) responses

Number of “very likely” (5) responses

Table 4. Distribution of High and Low Responses for the Likelihood ofClimate-related Impacts Within the Next Five Years.

Drought lowered water supply

Weather/Climate ConditionNumber of “never” (1)responses

Number of “10 or more times

per decade” (5)responses

Drought necessitated another watersource

Drought increased demand

Floods increased turbidity in surfacewater system

Floods damaged or contaminatedwells

High temperatures overloadedelectrical pumping systems

High temperatures caused higherdemand, strained supply

Electrical storms caused poweroutages, affected pumping

High winds caused power outages,affected pumping

16

22

2

19*

21

8

8

0

4

0

0

1

1*

0

4

4

9

4

Table 5. Vulnerability of Water Systems to Extreme Weather and ClimateEvents in the Past 10 Years.

* Surface water is actually used in 10 of the systems surveyed.

16

CLIMAS

ates a “hit or miss” pattern, producing up to severalinches of rainfall in localized areas over a span of underan hour, while leaving adjacent areas dry (Sheppard etal. 2000). Lightning occurs not only during the mon-soon season, but also notably before the rains actuallybegin. As with rainfall, lightning displays considerabletemporal and spatial variability across the region.

As water providers explained in the interviews, light-ning strikes can lead to power outages that affect waterdelivery and can disable wells through direct hits to thepumps. No water providers reported that they are“never” affected by electrical storms, while nine provid-ers said they were impacted 10 or more times per de-cade. Many providers noted that they are taking stepsto better cope with electrical storms that knock out theelectrical lines crucial to running their pumps, such asinstalling generators and other types of backup powersystems. High winds can also damage power lines andlead to electrical disruptions, which can affect plantsthat treat CAP and SRP water supplies. One provideralso noted that high winds raise water demand by in-creasing the evapotranspiration rate.

Water providers were asked during interviews to dis-cuss some of the most extreme climatic/hydrologicevents that their water service has experienced, whatthe major impact of each event was, and how their wa-ter system coped with it. As one provider noted,“Lightning strikes can take out our booster systems,and so can high winds. That type of weather is prima-rily monsoon related.” A particular type of monsoon-related phenomena, microbursts6, was cited as oneprovider’s “worst nightmare” in terms of disrupting thewater system.

Most providers who cited electrical outages said that ittakes an average of two to six hours to restore power,depending on the nature of the problem and how rap-idly they are able to dispatch repair people. The lengthof time that pumping could be disrupted before cus-tomers would notice varied from immediately, forminimally-buffered systems with no gravity-fed storageand little ability to reroute water between wells or drawon backup power sources, to several days (or never) forproviders who could effectively shunt water betweendifferent parts of their system or quickly switch tobackup generators. Interestingly, preparation for po-tential computer problems caused by the Y2K “Millen-nium Bug” was cited in several cases as spurring waterproviders to install backup generators on their pumps,which can now be used to compensate for lightning

strikes or electrical overloads. As one provider noted,“As our demand goes up, sometimes our reservoirscan’t keep up. It’s better now because we’ve got naturalgas backup generators, which we added in preparationfor Y2K.” Another provider said, “We’ve had ourpumps hit before, but thanks to Y2K preparedness,we’ve now got enough generators to cover that kind ofproblem. So the outages we do have are generallypretty short-term.”

High TemperaturesHigh temperatures ranked as the second most preva-lent response to survey question 4 regarding antici-pated climate-related impacts. The number of respon-dents who believed these conditions either very likelyor very unlikely to occur was relatively evenly distrib-uted, as Table 4 shows. High temperatures can increasedemand enough to strain water supplies and overloadelectrical pumping systems, and thus inhibit providers’ability to meet peak water needs during times of heavydemand. According to the responses to survey question6, high temperatures that increase demand enough tostrain water supplies were reported to “never” occur ineight systems, while four providers said that this oc-curred 10 or more times per decade (see Table 5). Hightemperatures leading to overloaded electrical systemsalready stressed by demand for power to run coolingsystems “never” occurred in eight systems, while fourreported this type of situation 10 or more times perdecade. In the interviews, providers noted that peakdemand times usually occur in May and June, whentemperatures are high and the monsoon rains have notyet begun.

FloodingFlooding can occur in the Southwest as a result ofshort-duration, highly localized and sometimes torren-tial summer monsoon storms; after longer-lasting,more widespread storms that occur due to offshoretropical storm activity in the Gulf of California andPacific; or during the winter, particularly in El Niñoyears. Monsoon-related flash floods ranked as a far lesssignificant concern in survey question 4, indicatingthat systems can normally handle the usually localizedand short-term effects. However, two interview respon-dents noted that flooding during monsoon season islikely to cause water lines to break or water mains tobecome exposed, while another reported that twoheavy monsoon storms had strained their sewersystem’s ability to run at three times normal capacity.Adverse consequences of increased surface water runoff,such as damage to or contamination of wells, or in-

17


creased turbidity, were infrequently noted. Twointerviewees, however, did cite flooding as the cause ofthe most severe climatic events to affect their systems.Long periods of increased precipitation, another typeof flooding-related disruptive weather listed in ques-tion 4, were considered unlikely to cause problems inmost study areas (see Pagano et al. 1999).

DroughtIt is surprising to find that in a region characterized bylow rainfall and rapid population growth, and follow-ing two of the driest winters in history, drought rankedonly as the fourth most likely climate-related impact.The weight given to this response varied significantlybetween and within study areas; those with shallowaquifers and no alternative water sources rated the im-pacts of this condition far higher than did those withdeeper aquifers and/or multiple water sources. For thepurposes of this study, drought was not specifically de-fined for water providers; instead, the responses todrought-related questions reflect providers’ perceptionsof what constitutes drought and how often it occurs.

Although winter rains and mountain snowfall are moreimportant to reservoir and aquifer recharge, droughtconditions and high temperatures that extend beyondthe normally dry April-to-June period are of greaterimmediate concern to water system managers. Muchof the increase in demand as the weather warms is re-lated to landscape watering and similar outdoor wateruses, which decreased markedly after the summer rainsstart. Delayed or scanty monsoon rains can signifi-cantly increase demand; indeed, several providers men-tioned this as being their “worst nightmare.” As illus-trated in Table 5, only two providers reported thatincreased demand due to drought is “never” a problem,while one reported this happening 10 or more timesper decade. As one provider responded when askedabout the most extreme hydrologic/climatic conditionshis system had been forced to cope with, “Hot and drysummer conditions caused a situation…where ourpumps couldn’t keep up with demand. It was a situa-tion where the monsoon started six weeks late, and itwas really hot. Evaporative coolers were what was mak-ing the difference—they really use a lot of water whenyou get enough of them going at once.” Another pro-vider commented on the impacts of delayed monsoonrains: “There have been a couple of times in the pre-monsoon season, when it’s been very hot and dry,when we’ve asked people not to wash their cars, notwashed the city fleet, and had (the city bus service) notwash their buses; but it’s been the kind of thing where

we do that for a week, and then the monsoons come.As soon as the monsoons come, our demand reallydrops.” Although many providers do currently havethe capacity to pump sufficient groundwater to com-pensate for higher demand and less surface water,maintaining this level of redundancy in a system de-spite significant population growth is considered a ma-jor challenge. Providers who depend solely on ground-water and are in areas with more climatically-sensitive,shallower aquifers would feel the impacts of both ashort-term delay in monsoon rains and more pro-tracted drought sooner.

A few water systems serve primarily winter visitors, the“snowbirds” that come to Arizona each winter to es-cape from colder climates. Those systems reported thattheir annual peak demand occurs in the winter andnoted fewer problems with meeting water needs due toless steep increases in demand. However, the managerof one such system said that summer demand does notfall as much as the population decline would suggest,because many winter residents leave their irrigationtimers set at the same rate year-round.

Low Temperatures and Long Periods of IncreasedPrecipitationProviders evidenced little concern with the types ofweather- and climate-related situations that are likelyto occur during the winter months. Low temperaturesand long periods of increased precipitation, as aremore likely to occur during El Niño years, were con-sidered unlikely to cause problems. Flooding in gen-eral, as previously discussed, ranked low in the re-sponses to question 6. Even in years when winterrainfall is scanty, demand is also far lower during thecooler times of the year, so water providers may notperceive winter droughts as problematic. Freezing ofpipes was noted to be a problem by only one waterprovider, who is located in an area that is colder in thewintertime relative to the other study areas.

Interview data from providers whose water supplies arederived from shallow, hydrologically-responsive aqui-fers showed that these groundwater-dependent systemsare quite vulnerable to both short-term and long-termdroughts. Other groundwater-dependent systems, incontrast, reported rising water tables and problemswith water logging due to their physical location downgradient from groundwater flows and due to the effectsof proactive recharge activities. These findings affirmthat it is inappropriate to lump all groundwater systemsinto a single category of either more or less vulnerable

18

CLIMAS

to climate impacts. Rather, it is necessary to view thesesystems in terms of a set of complex, interactive vari-ables—such as characteristics of aquifer deposits, aqui-fer depth, hydrologic connectivity of the groundwatersystem to surface events/conditions, and degree andnature of dependency on this source for different uses(as well as the criticality of those uses; that is, to whatextent is reduction or elimination of this type of wateruse feasible?). Given that much of the analysis of watersupply and demand budgets is produced at the AMAor watershed level, fine-scale variability can be glossedover, masking micro-scale climatic vulnerabilitiesamong water providers and consumers. These vulner-abilities may be exacerbated by lack of infrastructure toallow ready access to alternative water sources in timesof drought stress.

5.2 Size DOESN’T MatterDespite only including water systems classified byADWR as “large” (those that serve over 250 acre-feetof water per year), the study sample encompassed awide range of system sizes, serving from 485 to206,000 customers, with the median number of cus-tomers being 2,800. We hypothesized that:

Smaller water systems serving fewer people aremore sensitive to climatic variations thanlarger systems, due to a lack of capital to in-stall buffers such a storage space and addi-tional/deeper wells.

In order to understand the importance of size indepen-dently from the rate at which a water system mustgrow to accommodate an expanding population, wecompared the size of water systems (defined here asnumber of connections) with the total number ofweather and climate impacts experienced over the mostrecent 10-year period. Table 6 shows the aggregate ofthe number of times providers were affected by theconditions listed in Table 5, along with system size (interms of number of connections).

As the table illustrates, size alone does not appear to bea major factor in determining a system’s sensitivity toclimatic fluctuations. The systems that reported thehighest average number of disruptions are those in the10,001-50,000 range, while that those with 1,000-1,500 connections report the fewest disruptions. Al-though the number of systems surveyed is not largeenough for these results to be statistically conclusive,these findings suggest that larger, more complex sys-tems may actually be more vulnerable to weather- and

climate-related problems than smaller systems. As de-scribed in greater detail later in this report, smaller sys-tems are not more likely to have difficulty getting thefunding required to build and maintain adequate in-frastructure; nor are they less likely to engage in plan-ning for extreme climatic events such as prolongeddrought or floods. It is also worth noting that therewas no obvious correlation between number ofweather- and climate- related impacts and locationwithin the study areas.

5.3 Population GrowthGiven the importance of population growth on waterdemand, we hypothesized that

The rate of population growth is an importantinfluence on system vulnerability to climatevariability and change. However, the exact na-ture of this role is uncertain, since smaller,stable systems may not have the capital to putin buffers against climatic disruptions, but sys-tems in fast-growing areas might not be ableto keep up with growth.

This hypothesis was supported by our findings. Therecan be little doubt that population growth is the domi-nant focus in regional water planning, as Figure 3showed. Although water supplies may be adequate atpresent, the additional pressure that larger populationswill put on those supplies should be a vital consider-ation in coping with future climatic variability. Re-spondents believe that growth in much of the regionwill continue at a rapid pace into the foreseeable fu-ture, with overall expectations of 3 and 10 percentgrowth over the next 20 years. Several providers antici-

Table 6. Number of Weather and Climate ImpactsOver the Past 10 Years Based on Water System Size.

forebmuNsnoitcennoc

forebmuNsmetsys

forebmunlatoTdnarehtaew

stcapmietamilcsraey01tsaprevo

000,1< 4 71

005,1-000,1 4 11

000,3-105,1 5 91

000,01-100,3 5 81

000,05-100,01 3 72

000,05> 5 91

19


pated that their population would double by 2025,particularly in the rapidly growing suburbs of thePhoenix metropolitan area. Most providers intervieweddid not expect their areas to reach their full populationpotential, or build-out, for another 20 years. One pro-vider noted, “We’ve issued about 10,000 building per-mits per year for the past five years. Our secure watersupply is one of the reasons that companies are eagerto locate here.” Another provider said, “Our increasesin demand are all based on growth. To get an idea ofhow fast it’s growing, look at new building permits: in1994, 2,500 were issued; for 1996, it was 3,600; in1998, it was 4,200.” Another provider noted that thepopulation of his city had grown from 12,000 resi-dents in 1980 to 90,000 in 1999.

Negative effects of unrestrained growth, includinginsufficient fees charged to developers to cover addi-tional infrastructure, as well as environmental im-pacts upon endangered species, were mentioned asproblems in some areas, and believed by some to besignificant enough factors to redirect rapid growth toother areas.

Most of the growth in Arizona is in the form of newsubdivisions, which can range from a few dozen to sev-eral hundred homes constructed within a limited timeframe. One provider’s comments reflected the generaltrend: “All of the new growth is in subdivisions. Someof those subdivisions have limits on the amount ofgrass you can have; most homeowners’ associations callfor desert landscaping. They’ve also got parks and openspaces that use some water.” Although xeriscaping7 ispopular in many areas (particularly the Tucson AMA),and is required by some subdivision plans, high wateruse turf lawns are still being installed in some areas.Private golf courses are a significant water-use feature

in some subdivisions (although others are discouragingthem) and swimming pools are increasingly prevalentas well.

In order to evaluate exactly how growth is changingwater sources and systems, survey respondents wereasked about current trends and expected futurechanges in six different water demand and supply cat-egories. The results are shown in Table 7.

All 28 respondents report that they are currently expe-riencing an increase in the number of service connec-tions; only 1 of 27 anticipated a decrease in serviceconnections in the future. Given the ban on increasedirrigated agriculture within the three AMAs includedin the survey, it is not surprising that only 1 of 17 re-spondents indicated an increase in agricultural de-mand. Current conditions and anticipation of the fu-ture of industrial, municipal, and residential demandtrends show no such declines.

One would expect that increasing populations relianton groundwater resources would be drawing down wa-ter table levels, and this is the case in 15 of the 28 wa-ter systems queried. However, 10 systems indicated ris-ing water table levels, most likely due to greater use ofsurface water and increased recharge efforts, often in-corporating greater use of effluent. Seven systems an-ticipated that these actions would lead to increases inthe water table level in their areas the future, while 14anticipated decreases. Fewer respondents answeredquestions about surface water trends, probably due tothe lack of surface water sources within many serviceareas. Only one of seven respondents saw surface waterflows currently increasing, while four saw decreasesand two saw no change. One respondent indicated an-ticipating surface water increases in the future, perhaps

Table 7. Trends in Water Use and Water Availability.

etadotsdnerT segnahCerutuF

esaercnI esaerceD egnahCoN esaercnI esaerceD egnahCoN

snoitcennocecivresforebmuN 82 0 62 1

erutlucirganiesuretaW 1 61 1 61

esuretawlaitnediseR/lapicinuM 72 0 52 1

esuretawlairtsudnI 0 71 91 0

elbatretawdnuorG 01 51 1 7 41 1

wolfmaetS 1 4 2 1 3 1

20

CLIMAS

as further rights are secured; three anticipated de-creases, and one expected no change.

Providers were asked, “Given the current populationprojections for your area, what impact could extremeclimate conditions have on your company 10 or 20years from now? What’s your worst nightmare?” Amore specific question about an area’s growth rate andpattern (subdivisions, in-fill, industry) was added tothe interview protocol after several providers men-tioned this topic as important.

The comments of one provider incorporate the widerrealm of growth-related conflicting interests in manag-ing under drought conditions and illustrate the factthat the rate and type of growth an area is experiencinghave bearing on a water system’s ability to cope withclimatic variability:

Responses to drought between municipalities(as in deciding when a drought is occurringand what should be done about it) are heavilydependent on several factors such as ground-water quality, the particular mix of watersources, etc. This makes regional planning andresponding in a unified way difficult, becausethere are always local pressures not to declare adrought. Every water provider wants to be thelast to admit that they are having problems.There are times when it’s really important topresent a unified response, but it’s difficult todo. The media seize on every statement wemake. It’s all tied to development; the residen-tial development will come regardless, but forcommercial and industrial users, each towntries to woo them, and water supply and man-agement plays a role in their decisions.

Only one of the 15 providers interviewed who re-ported having a CAP allocation was currently using itsfull supply. Nine providers were using a portion oftheir allotments, while five had not yet started to usetheir allotments. Providers who had not yet started us-ing their CAP allotments or were not yet using theirfull portion said that the lack of infrastructure, such ascanals, pipes, and treatment plants, was the major hin-drance. A few of those who are utilizing at least part oftheir allotment had the treatment plants in operationto provide the water to customers through direct deliv-ery, but many more reported recharging their CAP wa-ter to replace mined groundwater, rather than using itdirectly. Providers in this category generally expect to

construct more treatment plants to treat CAP water fordirect delivery, particularly in the Phoenix AMA. Asone provider put it, “We’re not currently using our en-tire allotment because the treatment plant can’t yethandle the whole allotment. With our developmentrate, we will eventually need the whole allotment. Thepopulation of (our service area) was about 8,000 in1985; now it’s 100,000, and we expect to reach250,000 eventually.”

Increased utilization of their portions of Arizona’s CAPsupply is the major way that many water providers in-tend to keep pace with population growth. Most pro-viders with unused CAP allotments intend to meet in-creasing consumer demands through greater use of thisresource, and some mentioned that they could buylarger allotments if and when they need them. How-ever, this projected reliance on Colorado River watercould become problematic if a severe basin-widedrought combined with population pressures were tocause Arizona to have its CAP allocation significantlyreduced or totally suspended, as could occur under ex-isting law if there was insufficient water in the river tofirst meet the needs of Mexico, California, Nevada andnon-CAP senior rights holders in Arizona. Shorter-term disruptions to the CAP system could also occur ifextensive infrastructure repairs were needed. A fewproviders mentioned concerns about the reliability ofthe CAP supply. One noted that disruptions to eitherthe canal itself or to the electrical infrastructure neces-sary for pumping CAP water to Phoenix and Tucsonthat lasted longer than a month would result in a seri-ous water shortage. Another mentioned what hetermed “toxic terrorism,” the potential for deliberatecontamination of water supplies that might be possiblein many areas along the largely open-access canal. Asituation of this sort could have far-reaching conse-quences, particularly if such contamination spreadthroughout the CAP system.

Providers who currently utilize only groundwater ex-press little concern about overexploiting this water re-source. Most of these providers have made arrange-ments to recharge their CAP allocations and hence arerecording rising water tables. The majority of providersare also currently recharging effluent supplies or planto do so in the near future. Providers in areas withoutCAP allocations have the impression that groundwaterreserves are sufficient to handle the expanded popula-tion: “I’m not worried about it at all, because we’ve gotenough water and nothing is going to happen to it. It’sall up to the economy, when and whether those homes

21


get built, but there won’t be any problem no matterwhat.” However, some providers did express significantlevels of concern: “I expect that the situation will be-come more precarious due to declining water qualityin the aquifer. We’ve got very good water quality now,with no contamination problems, but in 20 years, Idon’t know. Even if there’s not much populationgrowth in this area, [a nearby municipality] is growinglike crazy, and it could still affect us.”

In contrast to the lack of concern regarding water sup-plies, some providers did express difficulties in ensur-ing that infrastructure was able to expand as rapidly aspopulation growth: “Based on our planning, no majorproblems are expected under normal conditions. Alack of infrastructure could become a problem, but ourresources look like they’ll be more than adequate tokeep up with growth. It does seem like we’re alwaysplaying catch-up to keep up with our 3 to 4 percentgrowth rate, and that’s expected to continue. We ex-pect build-out by 2010 or 2020.” Another providernoted, “We’re trying not to raise our rates, but it’stough with all the new subdivisions going in. We’vegot an 8 to 10 percent growth rate…”

If these providers are struggling to keep pace with sim-ply meeting the needs of their populations under nor-mal climatic conditions, it is unlikely that additionalstorage and precautions against changing climatic con-ditions are being taken. Although some providers didexpress concern about this, few believed that they werejustified in raising rates or asking municipal govern-ments for additional funds to further extend theirsafety margins.

Other providers were more sanguine about growth is-sues. They acknowledged that although growth is in-deed a major change occurring within their systems,developers are required to ensure that adequate infra-structure is built. As one provider summarized, “De-velopers are required to be 100 percent self-sufficient,and much of the infrastructure needed will be comingin before the actual developments, which should putus way over-capacity for quite some time.” Developersare also mandated to comply with ADWR’s 100-year as-sured supply rules, which at least in theory should limitconstruction to areas considered to have adequate watersupplies. (For a critique of the Assured Water Supplyprogram, see Carter and Morehouse 2001).

Both large and small providers expect greater consoli-dation of water systems over the next 20 to 25 years, as

municipal boundaries expand to encompass what arenow smaller, outlying suburbs. Thus some smaller wa-ter providers expect to be subsumed within larger ones,and some larger systems expect to expand their serviceareas by taking over smaller systems. These trends war-rant monitoring, both to assess the nature of and ex-tent to which vulnerability to climatic events maychange, and to identify how this may alter the natureand extent of climate information needs.

The Groundwater Code dictates that AMAs shouldachieve safe-yield (water withdrawals not greater thanreplenishment) by 2025, and thus the issue of growthis likely to become increasingly salient as the deadlineapproaches. For the non-AMA areas of the state, thisdate can serve as a convenient marker for estimatingand anticipating potential impacts of development onwater supply and demand, particularly as high growthrates are anticipated to continue in many of these ar-eas. Changes in the patterns in types and volumes ofdemand, in interaction with climatic variability, consti-tute potentially important sources of stress on both hu-man and natural systems. Working with providers,other community decision makers, and climate serviceentities over the next several decades to monitor changesin climate information needs—as these needs change inresponse to the nature and intensity of multiple stres-sors—could prove vital in averting adverse impacts onvulnerable natural and human systems.

5.4 Water Sources, Delivery, and DistributionInitial conversations with water management officialsand water providers indicated that having access to avariety of water sources and the ability to easily shiftdelivery between sources is an important buffer againstclimatic variability. Providers with access to more thanone water source spoke of the “level of redundancy” intheir delivery systems as a key means of ensuring that ifconditions such as long-term drought affected one sur-face water supply, they could mitigate adverse effectsby utilizing more groundwater or other surface watersources. These findings support our hypothesis that

Systems relying on only one water source aremore vulnerable to drought due to less redun-dancy in their water supplies and less flexibilityin their systems. Hence, the greater the numberof water sources a system can access, the lessvulnerable to climatic fluctuations it is.

Water providers who have access to multiple watersupplies believe that this is a formidable buffer against

22

CLIMAS

drought-related decreases in water supplies. Some ofthe providers who exhibited the highest degree of con-fidence in their water supplies were those who had ac-cess to surface water from both CAP and SRP sources.As one very large (>100,000 customers) providernoted, “We have the ability to switch between CAPand groundwater, or SRP and groundwater, if we needto…It’s possible that there could be a shortage on ei-ther the Colorado or the Salt/Verde, but the odds ofboth occurring at once are pretty slim.” Other multiple-source providers echoed the belief that while droughtmight affect one river system or the other, the odds ofboth the Colorado River Basin and the Salt/Verde sys-tem experiencing severe drought at the same time arevirtually nonexistent. However, analysis of tree-ringrecords by Meko et al. (1995) contradicts this assump-tion. This study found evidence of a severe droughtfrom 1566–1585 that extended throughout the entirewestern United States, significantly reducing flows onboth river systems for 19 years. Likewise, the currentdrought, while not yet of the magnitude of the 1500sdrought, has extended across both the Upper andLower Colorado River Basins, including the Salt-VerdeRiver system.

While shifting between water sources may be a usefulstrategy in coping with water supply disruptions, it isnot an option available to the majority of providers inthe study areas. As Figure 5 indicates, of the 28 re-spondents, only 11 reported using other water sourcesin addition to groundwater, and thus have other watersources available. Looking to the future, 9 additionalproviders expect to acquire the use of sources beyondnaturally recharged groundwater.

Of the 11 respondents who have access to watersources beyond groundwater, the two primary alterna-tive sources are CAP water (available in parts of thePhoenix and Tucson areas) and Salt River Project wa-ter, available only in certain portions of the PhoenixAMA. Of the systems having access to one or both ofthese water sources, CAP water supplies ranged from10 to 50 percent of total water use in individual serviceareas, while SRP water ranged from 8 to 60 percent oftotal supply. Most providers anticipated eventually us-ing a mix of CAP, SRP, and effluent supplies to fulfill 2to 95 percent of their water demand. In at least twocases, making a substantial shift to CAP water may beinterpreted as a strategy to cope with water shortagesidentified in the Third Management Plan for thePhoenix AMA (ADWR 1999a). Only one provider an-ticipates increasing use of SRP water.

Perhaps the most surprising finding to come out ofthis question is the low rate of anticipated future use ofeffluent. At present, effluent is used by five providers,with proportion of total supply ranging from 1 to 10percent, and neither the percentage of total supply nornumber of systems using effluent are expected to in-crease dramatically in the near future. In part, this maybe because the survey question asked about plans forthe next five years, and construction of separate efflu-ent delivery systems can take a long time. However,given the current high use of water for non-potablepurposes (such as landscaping, artificial lakes, and golfcourses), a more rapid and thorough incorporation ofeffluent into provider water budgets might have beenexpected.

In order to ascertain the vulnerability of water systemswith more or fewer water sources, each system’s num-ber of water sources was compared with the total num-ber of drought-related disruptions reported; then thenumber of drought-related disruptions was divided bythe number of systems in each “number of watersources” category. Table 8 displays the results.

As Table 8 illustrates, although systems with only onewater source did report that drought conditions hadaffected their systems in various ways over the past 10years slightly more often than systems with multiplewater sources, the correlation is not clear. The one sys-tem with five water sources reported only slightly fewerdrought impacts than average, while the five systemswith four water sources reported more drought effectsthan systems with only two water sources.

Some small systems that utilize only groundwater alsoreport that they can easily cope with both frequentcauses of disruptions such as lightning strikes and high

Figure 5. Percentage of Water Supplied by Groundwater.

0 5 10 15 20

<39%

69-40%

99-70%

100%

Number of Systems (out of 28)

Per

cent

age

of T

otal

Wat

er S

uppl

y

23


wind, as well as with less frequent occurrences such assevere drought. As the manager of one of the smallestsystems interviewed noted, “Even if the wind blew allthose power poles down, we have natural gas backupfor our pumps. We’ve also got two wells and could runwith just one if something happened to the other one.We’ve also got storage tanks. In 15 years, there’s neverbeen a situation where customers would have noticedany problems.”

Sustainability and Reliability of Groundwater vs SurfaceWater UseMost water providers intend to ensure long-term sus-tainability of water supplies in the face of rapid urbandevelopment and population growth by increasingtheir ability to shift between water sources, from reli-ance on groundwater to more readily renewablesources such as CAP, SRP, and effluent. Interestingly,the exact opposite strategy was identified in the surveyof providers in the Susquehanna River Basin: providerswere shifting to groundwater to enhance their resil-ience to climatic stresses (O’Connor et al. 1999). Insome respects, the Arizona providers’ shift to renewablesurface water supplies should reduce the area’s vulner-ability to long-term drought by ensuring that adequategroundwater remains in reserve for use if surface waterbecomes unavailable.

In urban water management in the Southwest,groundwater is viewed as fail-safe insurance againstdrought-induced water shortages that more readily af-fect surface water resources. However, groundwater inthe region is not considered to be an entirely renewablewater source. Researchers believe that much of the wa-ter in subterranean aquifers in the Southwest was de-posited during prehistoric periods when conditionswere much wetter than those currently found in the re-

gion. Depending on the geology, local climatic condi-tions and rate of use of groundwater reserves, the por-tion of groundwater that is replenished annually maybe only a fraction of the water withdrawn to meet hu-man needs. Strategies and infrastructure for movingavailable supplies to areas of critical need during a sus-tained drought, or other interruption in supplies, mayfail if these systems have not been adequately main-tained.

In recognition of the ultimately unsustainable natureof reliance on groundwater reserves to meet the de-mands of rapidly expanding populations, the ArizonaDepartment of Water Resources has mandated thatwater systems within its Active Management Areas bal-ance groundwater withdrawals with the best hydrologi-cal estimates of annual recharge amounts. However,these standards are based on assumptions of a stableclimate with precipitation levels and water suppliessimilar to those that have occurred over the past 100 orso years of record keeping, despite the fact that thelonger-term climate record suggests that the 1980sthrough the early 1990s (when most populationgrowth occurred) was actually one of the wettest peri-ods on record (Western Regional Climate Center2002). There is little evidence that providers seriouslybelieve that water supplies may be subject to decreasesfrom long-term dry spells or through contamination(due to either naturally-occurring concentrations ofcontaminants that increase as water tables drop, orthrough runoff from agricultural, industrial and mu-nicipal activities). However, in this arid region, warmer,drier weather generates significant increases in evapo-transpiration as well as in water demand for outdoor ir-rigation, cooling, and water-oriented recreational activi-ties. According to Boland, “If supply facilities and watermanagement policies continue to be based on an as-sumption of stationary climate, [warmer and drier] cli-mate . . .would lead to increased probability and severityof water shortages in the affected urban area” (Boland1997:158).

Water providers were asked what type of actions theywould expect to take in the event of a longer-term de-crease in water supplies, or in response to contamina-tion of water supplies. Respondents were given sevenpossible responses (including “other”) to a long-termoverall decrease in water supplies, as could occur witheither a long-term drought or actual climate change.Providers were asked to rate the likelihood of their em-ploying each of these solutions on a scale of 1 (veryunlikely) to 5 (very likely). The total points for each re-

Table 8. Number of Water Sources, Systems andDrought Impacts.

forebmuNretawsecruos

forebmuNsmetsys

thguordforebmuNtsaprevostcapmi

sraey01

1 61 6.5

2 5 3

3 0 a/n

4 5 8.3

5 1 5

24

CLIMAS

sponse were then added together and divided by 27 tofind the average. The results are presented in Figure 6.

The responses to question 7 can be grouped into thosethat would rely more heavily on the aquifer (drill newwells, deepen existing wells, draw upon another systemto which currently connected, draw upon another sys-tem you expect to be connected to in the future) andthose that would decrease human impacts on water re-sources (implement stricter water management/ration-ing, curtail future customers’ service). According to re-spondents, their most likely response to an overall

long-term decrease in water supplies would be to drillnew wells; the third most likely response would be todeepen existing wells.

Although measures that draw more heavily on ground-water supplies are among the most likely to be taken,their utility in coping with long-term climate change isdubious. Each of these remedies seeks to mitigate theimpacts of falling water tables and reduced surfaceflows by simply exploiting water resources moreheavily than has been done in the past. Drilling newwells, deepening existing wells, and drawing on thewater resources of other areas are limited solutions tosimply not having adequate water resources to sup-port the current consumption levels of expandingpopulations, particularly in times of prolonged cli-mate stress.

Strategies to decrease human impacts on water sources,such as implementing water restrictions and curtailingfuture customers’ service, provide more sustainableways of coping with water scarcity. However, theseremedies may be politically unpopular (particularlyamong growth-minded development interests) andmay also conflict with existing regulations. Under cur-rent Arizona Corporation Commission (ACC) regula-tions, private water providers cannot refuse water ser-vice to anyone requesting it within their serviceboundaries. Thus even if a water provider knows thatadding more customers will increase its overall demandmore than the supply can support, they must continueto provide connections. As one provider put it, “TheACC says that we have to provide water to anyonewithin our service area who wants it. There will comesome sort of breaking point where our demand out-strips what we can provide, and I don’t know what willhappen then.” Similar constraints limit the flexibilityof municipal water providers.

Expected Responses to Contamination of Water SuppliesSimilar responses were given to a question that askedwater providers to identify measures they might em-ploy if faced with contamination of their water sources(with the exception that curtailing future customers’service was not offered as an option). Using a tabulat-ing procedure identical to the one outlined for the pre-vious question, the results for this question are pre-sented in Figure 7.

Responses to this question were quite similar to thosefor the previous one, with the exception that drawingupon another system ranked higher than deepening

Other

Draw upon othersystem expect toconnect in future

Curtail futurecustomers’ service

Draw upon anothersystem to which

currently connected

Deepen existingwells

Implement stricterwater management

/ rationing

Drill new wells

1 2 3 4

Veryunlikely


Unlikely Likely

Figure 6. Likely Responses to Long-term Decrease inWater Supplies (Average of 27 responses).

Figure 7. Likely Responses to Contamination of WaterSources (Average of 27 responses).

0 1 2 3 4

Veryunlikely


Unlikely Likely

Other

Draw upon othersystem expect toconnect in future

Draw upon anothersystem to which

currently connected

Deepen existingwells

Implement stricterwater management

/ rationing

Drill new wells

25


existing wells. As previously men-tioned, in some areas water qualitycould become a greater concern intimes of climate stress. While drill-ing new wells or deepening existingwells might provide some short-termrelief, the utility of these responseswould be limited if contaminationwere widespread. Drawing uponother systems could offer some re-lief, but if the contamination oc-curred during a time of water scar-city, this might not prove a viablesolution.

Ability to Deliver GroundwaterAnother aspect of providers’ abilityto use groundwater reserves in theevent of severe sustained drought isthe capacity of their wells to remaineffective despite falling water tablesand diminishing supplies. Therefore, providers wereasked specific questions about well depth, depth to wa-ter and average well flow, which may all influence howseverely water systems might be affected by fluctuatingprecipitation amounts. Systems with shallow wells, andparticularly those drawing on shallow aquifers, wouldbe more immediately affected than those with deeperwells and aquifers. Respondents were asked to indicatethe minimum and maximum depth of their wells andthe average depth to water. As Figure 8 shows, there isconsiderable range in providers’ access to groundwaterresources.

These results indicate that the vast majority of systemshave maximum well depths deeper than 500 feet,much deeper than the average depth of water. This in-dicates that these systems would be well equipped torespond to water table declines, although they mighthave to deal with issues such as decreasing water qual-ity and increasing pumping costs as aquifers are drawndown, and might eventually reach a point wheregroundwater pumping is no longer feasible.

Reducing well flow has been cited as a way that waterproviders might cope with decreasing water resources.Providers who start with higher flow rates may be bet-ter able to endure reductions than those who have lowflow rates to begin with. The average well flow for therespondents was 816 gallons per minute, with a rangeextending from a low of 175 gallons per minute to ahigh of 2,100 gallons per minute (Figure 9).

Figure 8. Depth to Water, Minimum and Maximum Well Depths.

0

2

4

6

8

10

12

14

feet below surface

Depth to Water

Minimum Well Depth

Maximum Well Depth

50-250 251-500 501-750 751-1,000 1,001-1,500

>1,500

# p

rovi

de

rs (

n=

28

)

Current and Future Service CapacityIn order to assess the current and future service capac-ity of urban water systems in the study areas, providerswere asked about infrastructure such as the number ofwells and pumps, and the amount of reservoir capacityand miles of pipeline. These could be key determinantsin how water systems cope with weather- and climate-related problems, and help determine whether shiftingto groundwater supplies to cope with decreasedamounts of surface water is indeed a feasible strategy.For example, redundant well capacity means that somewells can be shut down if need be without deprivingcustomers of water; and high storage capacity allows

Figure 9. Average Well Flow.

0 2 4 6 8 10

50-250

251-500

501-750

751-1,000

1,001-1,500

>1,500

# Providers (n=27)

Gal

lons

Per

Min

ute

26

CLIMAS

systems to better cope with peak demand times andshortages. Therefore providers were asked about theirsystem’s infrastructure.

The results of these questions revealed a wide range ofresponses, such that it was impossible to ascertain bythis factor alone which systems have adequate capacityto manage their water resources in periods of droughtand unusually hot weather, or whether water managerscould respond to forecasts that indicate that high wateruse and low supply situations may be imminent. How-ever, responses regarding plans to expand infrastructurein the future did reveal that most systems see this as away of increasing their resilience to climatic variabilityand keeping ahead of population growth.

Looking to the future, most respondents indicated thatthey plan to increase the number of wells they operate,with 5 being the highest number of new wells planned.One provider intends to take 15 wells off line. Similartrends were noted in the number of pumps. As mightbe expected, the greatest number of new wells andpumps are, for the most part, planned by the providerslocated within the more rapidly growing residential ar-eas of the Phoenix and Tucson AMAs.

With regard to plans for future reservoirs and reservoircapacity, 22 of 28 respondents indicated expansion,ranging from one to eight new units. Likewise, the an-ticipated future reservoir capacity was expected to rise,ranging from 90,000 gallons to 275 million gallons,computing to an average of 20 million gallons and amedian of 5 million gallons. The variance in this casemay be attributed to the high number of smaller sys-tems included in the survey. Nineteen respondents in-dicated that they expected the number of miles ofpipeline to increase, a revealing indication of the extentto which urban sprawl persists in the region.

Connections with Other Water SystemsTo examine other possible means water providersmight employ to cope with disruptions to their watersystems, providers were asked whether they are a) con-nected to a neighboring community; b) have an agree-ment to purchase water; c) are in the process of con-necting with a neighboring community; d) neither, butare considering an agreement to buy water in emergen-cies; or e) not connected to any other water systems.Ten of the 28 survey respondents indicated that theyare not connected to any other water systems and haveno immediate plans to connect (Figure 10). Six out ofthe 28 indicated that they are connected to a neighbor-

ing community. Four respondents already had anagreement to purchase water. Another four respon-dents indicated that had an agreement to purchase wa-ter and were connected to another system. Only oneprovider indicated being in the process of connectingwith another community, while three said they wereconsidering an agreement to buy water in emergencies.

This question was pursued further during the inter-view process; providers were asked about the nature oftheir connections and how often they used them, orwhy they had not chosen to build interconnectionswith other water systems. Of the providers who hadconnections to neighboring communities, most saidthat the connections were only used in true emergen-cies. About half said that the connection had beenused only once or twice to their knowledge, while theother half said that such connections had never beenused. Some Phoenix AMA water providers are con-nected to other systems because of agreements to sharetreatment plants; several mentioned plans to makemore such connections as the AMA’s shift fromgroundwater to surface water continues.

Opinions about the value of interconnections foremergency purposes varied; as one provider noted,“Anytime I can get an interconnection, I’ll take it, be-cause it adds an extra layer of buffering, and it’s goodinsurance for both water services.” Another providerexpanded upon this: “It’s stipulated that they’re only tobe used in the event of an equipment failure or someother short-term problem, not for when they can’t

Figure 10. Connections to Other Water Systems.

0 2 4 6 8 10

Connected to a neighboring

community (a)

Have agreement topurchase water (b)

Connected and canpurchase water (a+b)

In the process ofconnecting w/ neighboring community (c)

Considering anagreement to buy water

in emergencies (d)

Not interconnected to any other

water systems (e)

Number of respondents (n=28)

27


meet their demand. We feel like if they’re going to bein the water business, they need to be able to take careof their system. It’s also stipulated that others using oursystem can’t adversely affect our customers.” These re-sponses indicate that relying on interconnectionswould not be an effective way of dealing with long-term drought. Other providers brought up concernsabout possible water quality issues associated with us-ing interconnections and potential problems with cor-rosion of pipes when switching between groundwaterand surface water.

Thus the ability to access multiple water resources ap-pears to be an important, but neither infallible nor es-sential, means by which urban water systems in theSouthwest may decrease their vulnerability to climate-related decreases in water supplies.

5.5 Short-term Service vs. Long-term SustainabilityAnother hypothesis relating to the importance of timescales on multiple levels in water planning was alsosupported by our findings:

Water systems dependent exclusively ongroundwater resources are essentially invulner-able to short-term climatic variability, but areat risk from long-term climate shifts towardsdrier weather.

Time is a crucial element in terms of both planningand population growth in the Southwest. We exploredthe groundwater/surface water relationship in the pre-vious section. However, this hypothesis caused us toconsider the importance of multiple time scales in twoadditional ways: 1) planning horizons; and 2) long-term climate-related vs short-term weather-related dis-ruptions to urban water systems.

Planning HorizonsThe means by which water managers plan for the opera-tions of their water systems and infrastructural needs isimportant in coping with potentially increased climaticvariability, water scarcity, and population growth. Un-derstanding the time frames that water providers use inplanning and budgeting for water suppliesand infrastructure has implications for howquickly water providers might adapt to long-term climate shifts; for example a providerwho plans only three years in advance mightmore easily incorporate new assumptionsabout water supplies and demand than onewho plans decades ahead, although longer-

term planning could include more realistic assessmentsof the sustainable use of water resources.

To assess this factor, providers were queried regardingthe perspective from which they engage in planningfor their operations, and the results are shown in Table9. Most providers said they take a middle of the roadapproach to planning based on actual past events ver-sus possible future events, although many lean moretoward planning based on possible future events. Thisindicates that water system managers do not relyheavily on what the recent conditions have been like,and that they plan in a way that would seem to bemore proactive in dealing with the possibility of differ-ent climatic conditions.

Another survey question asked respondents to indicatewhether or not they had ever found it necessary to re-evaluate their water budgets and, if so, why. Of the 23individuals who answered the question, 10 indicatedthat they had found it necessary to reevaluate their wa-ter budget, often due to unexpected climatic condi-tions. Reasons for reevaluation ranged from needing toaddress shortfalls in levels of reservoir storage, changesin water demand forecasts, and lower-than-averagerainfall and recharge.

Providers were also asked to indicate the time horizonassociated with water budgeting for their operations,and the results are presented in Table 10. The 24 indi-viduals who responded to this question indicated plan-ning time horizons ranging from 2 to 100 years, withthe longer time frames being punctuated by interimplanning as well. As Table 11 indicates, when planningcapital improvements, most respondents say they planfrom 1 to 5 years in advance, although a few use muchlonger planning horizons.

The ability to secure funding for capital improvementsnecessary to cope with long-term climate shifts couldbecome an important part of allowing water systems tocope with such changes, as well as in keeping ahead ofrapid population growth. In response to a questionabout efforts to fund capital improvements, repairs, or

Table 9. Estimating Budgetary Needs Based on Past andFuture Events.

*5ot1foelacS 1 2 3 4 5

esnopsersihthtiwsredivorp.oN 1 0 41 8 3

*1 being always planning on actual past events, 5 being planningahead for possible future events.

28

CLIMAS

expansion over the past five years, only 4 of 27 providersreported that they had not sought such funding, andonly 3 of 22 were unsuccessful in their efforts. Thus, in-accessible funding would probably not be a prohibitiveissue in adapting to different climatic conditions.

6. Implications

6.1 Low Concern About Climate-related DisruptionsThe relatively low level of concern among water systemmanagers about increased climatic variability contrastssharply with another study of the CLIMAS project, anassessment of the same four study areas of the sensitiv-ity of urban water sources to droughts of different du-ration (Carter et al. 2000). That study compared 1995and projected 2025 annual water supplies and demandwith the driest historic 1-, 5- and 10-year periods foreach study area and for the subwatershed of the middleSan Pedro River in Arizona. The study found that ifsimilarly dry climatic conditions were to occur withthe 1995 populations for these areas, the results couldbe significant, particularly for the longer-termdroughts. If droughts of this severity were to occurwith the projected 2025 populations, the consequencescould be worse. For example, the Phoenix AMA ex-pects to rely on groundwater overdraft to meet 24 per-cent of its annual water needs in 2025. However, if adecade-long drought of an intensity equal to the onefrom 1946–1955 were to recur, the AMA might needto mine as much as 39 percent of its water supply an-nually, leading to an additional four million acre feetof groundwater overdraft over 10 years (assuming thatno additional water resources become available, andthat no new conservation measures are implemented toreduce per capita water use). Even during a severe one-year drought, the AMA could end up mining 44 per-

cent more groundwater to compensate for shortages insurface water and CAP supplies, and to meet addi-tional water demand (again assuming no new watersupplies or additional conservation measures).

Potential reasons for the underassessment of vulner-ability on the part of water managers are three-fold.First, the depletion of groundwater resources may onlybe seen as problematic when it causes severe problemssuch as subsidence, declines in water quality, and/ormuch higher pumping costs. Long-term aquifer deple-tion is occurring in some of the study sites and was re-ported by some providers; however, as noted earlier,other areas are currently experiencing rising watertables as they shift towards greater use of surface waterfor both direct use and recharge.

A second reason for a lack of concern about climaticfactors may be that the decades of the 1980s and theearly 1990s were some of the wettest on record in ourstudy areas. During the period of 1980 through 1994,rainfall amounts averaged 17.73 inches, 26 percentwetter than the long-term median of 14.11 inches(Western Regional Climate Center 2002). Even thefew water managers who have been at their jobs formore than 20 years, since the late 1970s, may not real-ize that the recent past has been unusually wet, or beaware of the severity of past droughts. Although themost recent five years have averaged 10 percent belowthe median amount, this scarcely compares with thedriest five continuous years on record, from 1952–56,when rainfall amounts averaged 18 percent below themedian and when a single year’s total rainfall was 46percent below the median. The 1950s drought had adevastating effect on dry land agriculture and ranchingin the Southwest, although the impact on urban areaswas minimal. However, given the significant amount

Table 11. Number of Years Providers Plan Ahead for Capital Improvement Projects.

Note: 26 providers answered this question, but some gave their answers in ranges of years, indicating multipleplanning time frames; the endpoints of the ranges of years were counted as separate responses.

sraey5-1 sraey01-5 sraey02-11 sraey05-12 sraey15revO

sredivorP.oN 91 6 1 2 0

sraey5-1 sraey01-5 sraey02-11 sraey05-12 sraey15revO

sredivorP.oN 11 7 3 2 3

Table 10. Number of Years Providers Plan Ahead for Water Budget (Supply and Demand).

Note: 24 providers answered this question, but some gave their answers in ranges of years, indicating multipleplanning time frames; the endpoints of the ranges of years were counted as separate responses.

29


of urban growth that has occurred since the 1950s, if asimilar drought were to occur today, the toll on urbanwater systems could be severe and would likely resultin intensive negotiation between “wet water” and “pa-per water” rights holders.

A third reason for the apparent underassessment ofvulnerability to drought is that many (particularlysmaller) water providers tend to plan only for the moreimmediate future, from 1 to 10 years in advance. In-terview data indicates that the only planning that someproviders regularly undertake is annual fiscal planning.These providers deal with water supply and demand is-sues only as their systems require repairs or new subdi-visions necessitate expansion. The additional stress thatsubstantially higher populations in the region will haveon water resources, or the fact that a long-term shifttowards a drier climate is possible, may thus not be en-tirely appreciated. Even if smaller providers are awareof these potential problems, they may not have the re-sources or the latitude to plan for such events. One ofthe strongest messages generated by the interviews wasthat climate-related problems were secondary to theday-to-day challenges of managing a water service.

Whether the current drought will prompt greater in-terest in incorporating climate information into watermanagement operations remains to be seen. Efforts toincrease awareness among providers and regulatorswith regard to the track records of existing climateforecasts and scientific advances in climate and hydro-logical forecasting are both needed to address these is-sues. Such efforts will require time and persistence,particularly with regard to building ongoing, long-term relationships between scientists, climate servicesentities, and water managers and regulators.

6.2 High Provider Confidence in Their SystemsThe high degree of confidence expressed by providersin the capacity of their systems to withstand sustainedclimatic stress remains untested, since no severedecadal-scale drought has occurred since the 1950s,and the effects of that drought were relatively minimalin urban areas.8 However, very rapid urban growth anddevelopment have occurred since the 1950s, increasingthe likelihood that in the next decadal-scale severedrought at least some urban water systems will be sub-stantially affected. While the impacts of such a droughtwould certainly be unevenly distributed in terms of se-verity, geographical extent, and length of time, we be-lieve that all providers would benefit from a more cau-tious assessment of the resilience of their water systems.

The results of the provider survey further suggest thatthere is a generalized, if unstated, belief among watermanagers in the relative stability of the region’s cli-mate. Climate variability may be recognized, but onlywithin a restricted distribution on either side of thestatistical mean. Yet previous studies have demon-strated that the Southwest is in fact characterized by aquite high degree of variability (see, e.g., Sheppard etal. 2002). Research on the potential impacts of cli-matic change on the Southwest reinforces the need tothink more broadly in assessing the capacity of watersystems to hold up under climatic stress. As Miller(1997:1) observed, “The available evidence suggeststhat global warming may lead to substantial changes inmean annual streamflows, the seasonal distribution offlows, and the probabilities of extreme high or lowflow conditions…Rapid population growth, increasingenvironmental concerns, and resulting changes in thecharacter of water demands have led to increased com-petition for water even under normal flow conditions.These same changes contribute to increased vulnerabil-ity to hydrologic extremes.”

The lack of concern among most providers regardingpotential threats of climate-related problems to theirsystems does not reflect this perspective, nor does it re-flect the CLIMAS findings that urban water systemswould be heavily impacted by long-term drought(Carter et al. 2000). The results of our survey indicatethat providers rely significantly on heuristics in manag-ing their water systems (see Nicholls 1999). A keyquestion is whether their confidence in their systems’insensitivity to climatic variability is warranted. In afew cases, this may be true: all of the providers we in-terviewed had what they considered to be solid contin-gency plans for many other climatic problems theymight encounter. Even in these cases, however, the ac-tual effectiveness of the plans remains untested. Shoulda severe extended drought emerge that creates region-wide water shortages, it would be advisable to under-take economic and institutional analyses of the extentto which these plans worked as expected, of changingperceptions about the potential extent of climate im-pacts, and of changes in recognized climate informa-tion needs.

6.3 High Variability Among Water Systems andLocationsAs was discussed in the introduction to this report,each of the four study areas has a unique water de-mand and supply profile. Each area also appears to beheading in its own direction in terms of future water

30

CLIMAS

use. Further, the Phoenix, Tucson, and Santa CruzAMAs and the Sierra Vista subwatershed each exhibit aunique culture of water, an avenue of inquiry thatshould be pursued in future studies.

Phoenix AMAAn aerial view of the Phoenix AMA reveals not only ahigh percentage of single family homes with swimmingpools and green lawns, but also a considerable numberof water-intensive features such as human-made lakesand golf course developments. Indeed, the City ofTempe now boasts of its Town Lake in its economicdevelopment and tourism promotions. Adding to thesewater demands, the continued spread of urban growthin the greater Phoenix area consumes land every yearthat was formerly devoted to agriculture; yet agricul-ture persists and is not anticipated to disappear in thenear future (ADWR 1999a). Water logging in someportions of the Phoenix AMA appears to contradictthe message of the Department of Water Resourcesabout the need to conserve and to use water wiselyrather than profligately. By contrast, other provider ar-eas within the AMA are already expressing concernabout the sufficiency of water to meet demand. Suchunevenness across the AMA illustrates the complexityassociated with mapping climate vulnerability in thatarea, but does not diminish the need to think morebroadly about the implications of climatic stress forwater resource management. Water managers andregulators need to address more fully and directly thepotential impacts of a range of climatic conditions soas to decrease vulnerabilities and increase resiliencethrough an array of measures focused on adaptationstrategies in anticipation of future events and enhance-ment of coping capacity when climatic stresses actuallyoccur.

Tucson AMAPortions of the Tucson AMA stand in stark contrast tothe profile of the Phoenix AMA depicted above. Al-though there are golf courses and swimming pools,xeriscaping is more readily apparent in this area, par-ticularly in new subdivisions where landscaping rulesapply. Yet even here a spectrum of vulnerability exists,although no system is as heavily buffered by multiplewater sources as some of the Phoenix-area systems. Inpart, this is due to the fact that Tucson is at the end ofthe CAP system and would likely feel the effects of ashortage of CAP water before providers in Phoenixwould. Further, Tucson lacks any alternative sourceanalogous to the SRP in Phoenix. Thus, groundwaterand effluent are the only two fallback sources currently

available. As in Phoenix, some providers are distantfrom the CAP canal and are unlikely to ever be con-nected to that source of supply. Most of these provid-ers currently participate in a CAP-based groundwaterreplenishment program that is designed to offset thenon-renewable water that they pump; however, the re-charge areas are typically not located nearby and no in-frastructure currently exists to move the water from thearea of replenishment to the area of potential need.Such geographical and infrastructural constraints, aswell as the institutional constraints mentioned earlierin this report, increase the potential vulnerability ofthese providers. An explicit dialogue within the AMAregarding potential climatic implications for watermanagement is essential to enhancing the resilience,adaptation, and coping capacity of local providers.

Santa Cruz AMAThe landscape of Nogales, the largest city in the SantaCruz AMA, tends toward smaller yards, minimal useof water-intensive landscaping, and less water use over-all. In contrast, the town of Rio Rico is promoting it-self as a golf resort, with consequent higher water use.Providers in Nogales may be somewhat more cognizantof the potential for climatic conditions to pose chal-lenges to water management. Because much of thecity’s water is currently supplied from shallow aquifersthat are highly responsive to variability in precipita-tion, even short-term weather events are readily re-flected in water supply. Furthermore, the city’s locationon the U.S.-Mexico border, and its adjacency to amuch larger sister city across the border (Nogales,Sonora has a population of more than 200,000) makeswater management an international affair, particularlyduring times of drought or flood (see, e.g., Ingram etal. 1995, Morehouse et al. 2000). Here, convincingwater providers to broaden their perception of possibleclimatic stresses affecting both sides of the border maybe the greatest need. Also important is persuading pro-viders to think beyond the confines of the current cli-mate to consider possible scenarios based on conceptsof climate non-stationarity and longer-term climaticchange in the transboundary region.

Sierra VistaThe Sierra Vista area includes a medium-sized city andseveral nearby small towns. The area is characterized bya widely dispersed settlement pattern. While mostpeople live in single-family subdivisions, and most ofthe homes are now xeriscaped, a significant numberlive on larger plots of land. These “ranchette” develop-ments are extending outward at an ever-increasing dis-

31


tance from the population centers of Sierra Vista,Huachua City, Palominas, and Nicksville. Many ofthese residents have their own wells. While no singlewell draws a large amount of water, the fact that thereare so many of them has been cited as a significant fac-tor associated with generalized decreases in the localwater table (Glennon and Maddock 1994). Cones ofdepression have formed where groundwater pumpinghas been most intensive, and these cones are now con-verging to produce a more widespread drop in the wa-ter table. Projections indicate that the population willcontinue to grow rapidly, aggravating the imbalancebetween renewable supply and demand, even undercurrent “normal” conditions. Effluent management hasbeen identified as the one alternative the area currentlypossesses to address the situation, and projects are un-derway to maximize the capture and reuse of this re-source. However, changes in climatic conditions overperiods of several years, decades, or even longer havethe potential to stress water operations in the area, andto pose serious threat to the nearby and highly valuedSan Pedro National Riparian Conservation Area. En-suring the long-term viability of the river and its habi-tat, while allowing for continued urban growth, re-quires that climate information be taken more fullyinto account in both planning and routine operations.Interest exists in using such information. This oppor-tunity needs to be actively pursued, especially with re-gard to development of information and forecastsscaled to the local level.9

6.4 Current Use of and Interest in ClimateInformationAs this report illustrates, the number and types of cli-mate-related stresses that providers said they had facedvaries considerably. Many providers mentioned theweeks or months leading up to the monsoon season asstressful, while others recalled flooding incidents thatoccurred in the 1980s and 1990s. However, no pro-vider in any of our study areas has yet been forced todeal with a severe, long-term drought. The impacts ofcurrent drought conditions, which intensified after wehad completed our survey, on urban water systems re-main to be assessed. Given that most providers havemanaged to cope with climatic variability withoutgreat difficulty in the past, and have for the most partdone so without benefit of climate forecasts or relatedinformation, it is little wonder that few automaticallyrecognize the value of such information. As previouslydiscussed, providers believe that they have enough“solid” information in the form of population projec-tions and demand, as well as past supply conditions, to

make their water management decisions, without at-tempting to use forecasting tools. Providers regularlysituate their decision making within a complex arenaof sometimes conflicting and contentious policies andinstitutions, and emphasize the fact that they must ne-gotiate between local, state, and federal water manage-ment entities and their customers. These types of chal-lenges greatly overshadow any concerns regardingpotential climate impacts.

Few providers used longer-term climate informationfor planning purposes. Instead, current population andexpected growth are the primary criteria. It is not sur-prising that data of this nature would seem much morereliable than uncertain climate forecasts, due in part,no doubt, to water managers’ lack of knowledge offorecasting products and how to use them. Undoubt-edly, the planning cycles and organizational structure ofthe individual operations play a significant role in theprioritizing of what is important to consider in planningand budgeting activities. However, recent interest in ini-tiating drought planning (see, e.g., Governor’s WaterManagement Commission 2001; Slivka andMcKinnon 2002) may prompt providers to develop amore open mind toward using climate forecasts andother such information.

Interview information reveals that water providers arenot seriously considering the possibility of reduced wa-ter supplies and that few providers are even concernedabout the outcome of ongoing litigation over Indianwater rights. Yet some of these water rights cases, in-cluding the current adjudication of all rights to watersof the Gila watershed, have the potential to reallocateconsiderable portions of the existing water supply. It isnot inconceivable that, under climatic stress, providerswould need to negotiate with specific tribes to pur-chase water to cover unmet demand.

Another factor in the lack of interest in using climateforecasts (or other climate information) is the need tomaintain an adequate revenue stream. Revenues areneeded not only to sustain operations but also to ad-dress infrastructure repairs and expansion. For mostproviders, such considerations override considerationof long-term sustainability goals, such as those re-flected in the safe-yield provisions of the ArizonaGroundwater Management Act. By assuming that wa-ter supply is a constant, and that demand will increasein a linear fashion along with population, water pro-viders simplify their planning process considerably.Regulatory changes that have the effect of encouraging

32

CLIMAS

or requiring greater consideration of climate variabilityin calculating prices charged to customers, revenuestreams, infrastructure requirements, and contingencyplanning needs may be required to change ways of do-ing business in the water management sector.

Indeed, while the effects of a severe long-term droughton water supplies and consequently on water systemscould be dramatic, so too could the impacts of an ex-tended wet, cool period. In an informal discussion out-side the survey process, one provider noted that theanomalously wet summer of 1999 had reduced rev-enues more than the utility would have preferred. Ex-tending such concerns over longer periods suggeststhat the unpopular and difficult step of raising waterrates might be required in the absence of contingencyplans that could buffer against wide oscillations in rev-enue streams. Under such scenarios, providers mightnot have sufficient funds to sustain operations and in-frastructure. For private water companies, raisingenough revenue to sustain themselves as viable busi-nesses could prove challenging, especially given theACC’s historically conservative attitude toward allow-ing rate hikes. As suggested by interviewees, the futureis likely to be one where water companies are increas-ingly consolidated under the ownership of large corpo-rations. Water company stocks will be more extensivelytraded on stock exchanges, and water itself is likely to betraded on commodity markets. Trading in climate de-rivatives, already underway, may be expected to grow inimportance. Under these conditions, it is very likely thatclimate information will become an increasingly impor-tant adjunct to planning and decision-making. Thoseproviders who wish to remain in business and to effec-tively compete would do well to enhance their use of cli-mate information now, in preparation for the future.

6.5 Strategies for Enhancing the Use of ClimateInformationRecognizing that the different study areas have varyingwater supply and demand issues, as well as multipletypes of water resources, climate information ideallyshould be tailored to address the diversity of needs.This will not always be possible, but the differences ininformation needs should be taken into account whenissuing climate information to the different providers.

To make climate forecasting relevant and useful to wa-ter providers, several steps should be taken. Most im-portantly, the forecasts and other information need tobe reasonably easy for providers to interpret, and pro-viders should be trained in how to use the information

most effectively. While several providers expressed aninterest in learning more about climate forecasts andhow to use them in planning and decision making,none said that they had sufficient time or inclinationto undertake such learning on their own. As a corollaryto this recommendation, the information must be eas-ily accessible to providers and issued at the times theproviders most need that particular information.

As emphasized by several of the providers surveyed,forecasts and other such information need to bebacked up with data attesting to their accuracy overtime. Until recently, assessment of forecast accuracy(“skill level”) was sparse to nonexistent. CurrentCLIMAS research activities designed to fill this gap arean important contribution to addressing this need (see,e.g., Hartmann et al. 2002). Findings of the surveydiscussed in this report reveal that, to assure user ac-ceptance, the forecast evaluations need to be supple-mented by a “test period” in which providers test theaccuracy and utility of the forecasts themselves, beforetheir use can become a regular factor in their planningand decision-making activities. This finding echoes theresults of Pagano et al. (1999), in which water andemergency response managers were found to expressconfidence in the 1997–1998 El Niño forecasts whenthe forecasts accorded with their own in-house infor-mation or their past experience. Such reliance on heu-ristics is typical (see Nicholls 1999), but may be one ofthe more difficult hurdles to clear in efforts to effec-tively communicate climate information to stakehold-ers such as water managers.

7. Conclusions

As the population and competition for water resourcesincreases, water providers and decision makers will facenew and more intense challenges. Vulnerability to cli-matic conditions already exists among some water pro-viders and even more are likely to be affected, particu-larly if a severe sustained drought should recur or if thefrequency of severe events, such as electrical storms, in-creases. A few urban water systems are well bufferedagainst climate stresses by having access to multiplewater sources, including both groundwater and surfacewater resources, but many are not. Recognition amongproviders of their own potential vulnerability, however,is low. High confidence in existing buffering capacitycontributes to this mind set. Other contributing fac-tors include insufficient understanding of how climateinteracts, or could potentially interact, with existing

33


structural and institutional arrangements to produce orexacerbate systemic vulnerability. The lack of recogni-tion may also be related to excessive reliance on per-sonal experience, outdated professional knowledge, orsimple lack of imagination about possible futures.Overcoming these perceptual barriers is no easy task.However, strategies do exist for enhancing capacity tounderstand vulnerabilities and develop greater resil-ience to climatic impacts.

On the research side, continuation of research in re-gionally relevant climatology and hydrology is essen-tial, as is integrated climate impacts assessment workdesigned to improve knowledge about climate pro-cesses and impacts of particular salience to the South-west. Advances in capability to downscale climate fore-casts would be especially useful. Likewise, outreachactivities, which facilitate the two-way flow of infor-mation between researchers and the public, are crucialto ensuring the relevance of research results to stake-holder needs and to formulating research agendas.Continued work on improving the theoretical andmethodological foundations for generating and diffus-ing new knowledge is essential for broadening the ar-ray of questions that can productively be answered byscience.

Effective communication of climate information isequally important. To be useful to water providers, theinformation must be provided at the appropriate tem-poral and spatial scale(s) for the specific area in ques-tion and must be provided at the time that particularinformation is needed. The scales and timing of infor-mation will vary, depending on factors such as whetherthe information is to be used for long-term planning,operational decision making, or other reasons. Know-ing what information is needed, at what scales, and atwhat time—and in what format—requires ongoing in-teractions with stakeholders. Likewise, ensuring that theinformation is effectively used requires well-designededucational efforts that fill gaps in providers’ under-standing of climate processes, the basics of forecasting,and interpretation of information. Simplifying accessto information and ensuring that providers know, atany given time, where such information may befound is equally important, because today there aremyriad climate information sources from which tochoose. Being certain that providers know which in-formation to use for specific purposes is essential tobuilding their confidence in the quality, reliability,and utility of that information. Indeed, enhancingstakeholder confidence in climate information and

forecast products may be one of the more serious chal-lenges to maximizing resilience and coping capacity inthe face of serious climatic stresses we are likely toeventually face.

Endnotes

1 Untreated water providers deliver water not treated todrinking water standards to industrial users such asgolf courses, parks, etc.

2 Groundwater recharge in this context involves fillingretention basins with CAP water and allowing it to in-filtrate the aquifer, where it is naturally filtered andmixed with fossil groundwater. The water is thenpumped back out for delivery to customers.

3 All responses to each factor were added togetherbased on a score ranging from 5 for most important to1 for least important, regardless of whether the respon-dent had strictly complied with the instructions to thequestion by choosing only the five most important fac-tors; some respondents ranked less than five choices,and some more than five. No provider rated any onefactor higher than five.

4 This question was taken verbatim (with permission ofthe authors) from the Susquehanna River Basin Inte-grated Assessment discussed in the Background sec-tion. To produce Figure 4, the numerical responsesfrom the 27 respondents who answered the questionwere added together. The average score was derived bydividing this number by 135, the total that would havebeen achieved if all respondents had chosen 5 (verylikely). Two respondents chose answer 6, meaning“don’t know,” for two of the questions; these responseswere changed to a 3, so as not to skew the totals. Thus,the fact that electrical storms have the highest numeri-cal score indicates that providers view this as the mostimportant factor, awarding it more 5-point responsesand fewer 1-point responses.

5 This question was also modeled after a similar ques-tion asked and tested by the Susquehanna assessment,although minor alterations were made to make thequestion more appropriate to conditions in theCLIMAS study areas.

6 Sudden, intense, and highly localized weather activitythat can generate torrential rains, numerous lightningstrikes, and winds of up to 70 mph.

34

CLIMAS

7 Xeriscaping is the use of low-water use vegetation andinorganic groundcover such as gravel for landscaping.

8 The most severe drought in recent history is the1950s drought, lasting from 1947–1956. During thistime frame, approximately 74 percent of the mean av-erage rainfall of 14.33 inches fell each year. The effectsof this drought were widespread and severe, with heavylosses in both ranching and crops. Despite having lesstechnologically advanced water management systems,urban areas generally coped fairly well. If such adrought were to occur today, however, the effects couldbe quite severe in urban areas. Such a drought scenariowas tested against population projections for 2025 ineach of the study areas in the CLIMAS SensitivityAnalysis (Carter et al. 2000). The results were a 10 to15 percent increase in groundwater overdraft. If such adrought were widespread and long-term enough to af-fect CAP allotments, and in the absence of effectivewater conservation and demand management, thePhoenix AMA would be forced to rely on nonrenew-able groundwater supplies to meet 59 percent of its to-tal water needs (in contrast to the normal expectedoverdraft of 24 percent). In the Tucson AMA, 75 per-cent of its water needs would have to be met using non-renewable groundwater resources (up from the projectednormal overdraft of 15 percent of total supplies).

9 We recognize that scientific capacity to downscaleforecasts to the local level is quite limited; however,continued dialogue with water managers may produceproducts that contribute substantially to decision mak-ing under conditions of climatic variability andchange.

References

ADWR. 1999a. Third Management Plan, Phoenix Ac-tive Management Area. Arizona Department of WaterResources, Phoenix.

——. 1999b. Third Management Plan, Tucson ActiveManagement Area. Arizona Department of Water Re-sources, Phoenix.

——. 1999c. Third Management Plan, Santa Cruz Ac-tive Management Area. Arizona Department of WaterResources, Phoenix.

——. 1991. Hydrographic Survey Report for the SanPedro River Watershed, Volume I: General Assessment.

Arizona Department of Water Resources, Phoenix.Boland, J. J. 1997. Assessing urban water use and therole of water conservation measures under climate un-certainty. Climatic Change, 37:157–176.

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Appendix A: Survey

Name of Water Provider Person completing surveyLocation PositionApproximate # of customers Years in Position

1) From which water using sectors are your customers? Please indicate the percentage of each:• Industrial (including turf ) %• Municipal/Residential %• Other sector % Specify sector:

2) What are your primary sources of water at present? Do you expect any changes in water source duringthe next five years? Please indicate the percentage of each water source, both now and in the next five years:

current sources: future sources:• Groundwater % %• Surface water % %• CAP % %• SRP % %• Effluent % %• Other % %

3) If you use groundwater, how deep are your wells? From to feetWhat is the average depth to water? feetWhat is the average flow of your wells? gallons per minute

4) How likely is it that the daily operations of your water system will suffer climate-related impacts within thenext five years? (Circle the number that reflects your best estimate.)

5) Is your system regionalized or otherwise interconnected with any other water systems?

A Yes, we are connected to a neighboring community

B Yes, we have an agreement to purchase water

C No, but we are in the process of connecting with a neighboring community

D No, but we are considering an agreement to buy water in emergencies

E No, we are not interconnected to any other water systems

yreV yreV yreV yreV yreVylekilnu ylekilnu ylekilnu ylekilnu ylekilnu

ylekilnU ylekilnU ylekilnU ylekilnU ylekilnUyllauqE yllauqE yllauqE yllauqE yllauqEdnaylekil dnaylekil dnaylekil dnaylekil dnaylekil

ylekilnu ylekilnu ylekilnu ylekilnu ylekilnuylekiL ylekiL ylekiL ylekiL ylekiL ylekilyreV ylekilyreV ylekilyreV ylekilyreV ylekilyreV

t'noD t'noD t'noD t'noD t'noDwonk wonk wonk wonk wonk

A thguorD 1 2 3 4 5 6

B doolfhsalF 1 2 3 4 5 6

CdesaercnifosdoirepgnoL

noitatipicerp1 2 3 4 5 6

DretawecafrusdesaercnI

gnitanimatnocffonurretawecafrus/dnuorg

1 2 3 4 5 6

E serutarepmethgihylemertxE 1 2 3 4 5 6

F serutarepmetwolylemertxE 1 2 3 4 5 6

G smrotslacirtcelE 1 2 3 4 5 6

H sdniwhgiH 1 2 3 4 5 6

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CLIMAS

6) On average, in what ways has your current system been vulnerable to extreme weather and climate eventsin the past ten years? For each of the items below, indicate how many times in a typical decade that yoursystem has suffered some form of difficulty due to the types of events listed below.

7) If your water source became unstable due to long-term overall decrease in water supplies, which of thefollowing solutions would you employ?

reveNsemit2-1

repedaced

semit5-3rep

edaced

semit9-6rep

edaced

eromro01repsemit

edacedA ehtderewolsnoitidnocthguorD

metsysehtniretawfoylppusslevellanosaeslamrondnoyeb

1 2 3 4 5

B otsudecrofsnoitidnocthguorDecruosretawrehtonakees

1 2 3 4 5

C tnacifingisotdelsnoitidnocthguorDmetsysruonodnameddesaercni

1 2 3 4 5

D ruoniytidibrutdesaercnisdoolFmetsysretawecafrus

1 2 3 4 5

E rodegamadotdelsdoolFsllewdetanimatnoc

1 2 3 4 5

F serutarepmethgihylemertxEdnastiucriclacirtcelededaolrevo

smetsysgnipmuptuodekconk1 2 3 4 5

G evahserutarepmethgihylemertxEniartsothguonednameddesaercni

ylppusretawruo1 2 3 4 5

H rewopotdelevahsmrotslacirtcelEotytilibaruotceffatahtsegatuo

sremotsucruootretawpmup1 2 3 4 5

I rewopotdelevahsdniwyvaeHotytilibaruotceffatahtsegatuo

sremotsucruootretawpmup1 2 3 4 5

J _____________________rehtO_________________________

1 2 3 4 5

yreVylekilnu

yreVylekil

A hcihwotmetsysrehtonanopuwarDdetcennocyltnerrucerauoy

1 2 3 4 5

B uoytahtmetsysrehtonanopuwarDerutufehtniotdetcennocebottcepxe

1 2 3 4 5

C tnemeganamretawretcirtsatnemelpmI)gninoitar(nalp

1 2 3 4 5

D ecivres’sremotsucerutufliatruC 1 2 3 4 5

E sllewgnitsixenepeeD 1 2 3 4 5

F sllewwenllirD 1 2 3 4 5

G _____________________rehtO_________________________

1 2 3 4 5

39


8) If your water source became unstable due to contamination, which of the following solutions would yoube likely to employ?

9) What sort of infrastructure does your water company possess?Do you intend to expand or decrease this infrastructure within the next five years?

current expected future• Number of wells:• Number of pumps:• Number of reservoirs:

Storage capacity:• Miles of pipes:• Miles of canals:

10) Which factors are most important in limiting the number of customers that you can serve? Please identifythe five most important and rate them from 1 to 5, with 1 being the most important:

_____ Water rights _____ Limited access to capital for expansion_____ Water availability _____ Limited economic returns_____ Competition with other water providers _____ Limited infrastructure_____ Personal preference _____ Market saturation

(small company atmosphere, etc.) _____ Other (please specify) ___________________

11) Which factors are most important when developing your water budget (supply & demand)?Please identify the five most important and rate them from 1 to 5, with 1 being the most important:

____ Current population ____ Groundwater table ____ Agricultural acreage____ Population projections ____ CAP availability ____ Urban development plans____ Transitory population ____ Effluent reuse rate ____ Economic development (tourists, snowbirds, etc.) ____ Current and past climate data plans____ Streamflow data ____ Climate forecasts ____ Other: __________________

12) How far in the future do you plan your water budget (supply & demand)? years

yreVylekilnu

yreVylekil

A hcihwotmetsysrehtonanopuwarDdetcennocyltnerrucerauoy

1 2 3 4 5

B uoytahtmetsysrehtonanopuwarDerutufehtniotdetcennocebottcepxe

1 2 3 4 5

C tnemeganamretawretcirtsatnemelpmI)gninoitar(nalp

1 2 3 4 5

D sllewgnitsixenepeeD 1 2 3 4 5

E sllewwenllirD 1 2 3 4 5

F _____________________rehtO_________________________

1 2 3 4 5

40

CLIMAS

13) Have you ever had to reevaluate your water budget? yes noIf yes, why?

14) To date, have you identified any trends in water use and water availability within your service area?Do you foresee any additional changes for the future? Please indicate an increase (I) or decrease (D):

Trends to date Future changes

• Number of service connections I D I D• Water use in agriculture I D I D• Municipal/residential water use I D I D• Industrial water use I D I D• Groundwater table I D I D• Streamflow I D I D• Other (please specify) I D I D

15) When preparing capital improvement projects, how many years in the future do you typically plan ahead?_______________________ years

16) To estimate budgetary needs, some individuals prefer to look ahead and consider all possible difficulties ofwhat could happen to their system, while others look back at the events that actually affected their system. Onthe scale below, please estimate how your system estimates its future improvement needs.

Always plan based on Always plan ahead foractual past events possible future events

1 2 3 4 5

17) Have you acquired or attempted to acquire funds to pay for major capital improvements, repairs, or expansionin the last five years?

Yes No

If yes, was your attempt successful?

18) In the course of your duties, how often do you consult:

• Weather forecasts (current to two weeks into the future)

• Climate forecasts (more than two weeks into the future)

• Hydrologic forecasts

Thank you for your information!

41


Appendix B: Interview Questions

Interview withName of Water Service

A. Internal Policies and Institutions

I’d like to start out by asking you a few basic questions about your operation here:

A1. How many employees does your water company have?

Are any of those people involved with climatology or hydrology?

A2. How is your service structured?

Under normal conditions, who makes decisions for your company?

A3. What type of pricing structure do you use now?

A4. What might cause your company to change its pricing structure? (for example, in case of an extendeddrought…)

What’s the development rate and pattern around here?

A5. Have you ever had to ration water to customers?

A6. What is your gpcd rate? Are you being asked to reduce it?

A7. When will CAP use get underway on a widespread basis?

A8. What are your current recharge plans? Future plans?

B. Climate and Hydrologic Variability - Past, Present & Future

B1. You had noted on the survey that drought, high temperatures, and electrical storms have caused problems toyour system in the past. What were some of the most extreme climatic/hydrologic events that your companyhas had to deal with? Examples?

B2. What was the major impact of each? How did you cope?

How long could an outage go on before customers would notice?

B3. What information was available to warn you that this event was going to occur, and about how severe itmight be? Where did you obtain this information?

B4. Were you able to prepare for those conditions? How?

B5. Given the current population projections for your area, what impact could extreme climate conditions haveon your company in 10, 20 years from now?

What’s your worst nightmare?

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CLIMAS

B6. What types of climatic and hydrologic conditions are most advantageous to your water company? Howfrequently do these conditions occur?

C. External Policies & Institutions

C1. I see that you have interconnects to provide water to smaller systems during emergencies…have you had touse these often?

Do you negotiate with any other water users or water managers regarding the acquisition, allocation, anddistribution of water resources? Who and how? Under what conditions? Please explain.

C2. Who else do you interact with? (for example, oversight committees, agencies, public interest groups, politicalentities, etc.)

Does this change during times of climate stress? How?

C3. Will any of the pending Indian water claims affect you?

C4. Do you or does anyone from your operation serve on any committee or board as a water provider?

C5. What changes in laws, policies, and procedures would you consider most useful in enabling your organizationto better deal with climate stresses on your system?

D. Forecasting Information and Needs

D1. When do you do your annual planning?

D2. How often do you do longer-term planning?

D3. Do you use any climate/hydrological information and forecasts in planning (for example, history oftemperatures and precipitation for this area)? What types of information and forecasts? On what time scaleand over what geographical extent?

D4. Are you satisfied with the information you use? Advantages? Disadvantages?

D5. What are the biggest gaps in your current information? What information do you need most that you don’thave?

D6. If there was a “one-stop shopping center” for climate/hydrologic information, would you use it? How wouldyou prefer to access it (internet, fax, radio, personal visit, etc)?

D7. Would improved information about climate and hydrology influence public understanding about wateravailability in your community? How might it help?

D8. Would using improved climate/hydrologic information change the development process in your community?How?

D9. Where do you see your water company in the year 2025?

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