efficient water use for texas - texas a&m university

Policies, Tools, and Management Strategies

Prepared for Environmental DefensebyTexas Agricultural Experiment StationTexas A&M UniversityCollege Station, Texas September 2002

Efficient Water Use for Texas:

Jan GerstonTexas Water Resources Institute,

Texas A&M University, College Station, Texas

Mark MacLeodEnvironmental Defense, Austin, Texas

C. Allan JonesDirector, Texas Water Resources Institute

AcknowledgmentsThe authors would like to express their appreciation to the following internal

and external reviewers: Carole Baker, The Harris–Galveston Coastal SubsidenceDistrict; Janie Harris, Texas Cooperative Extension; Hari Krishna and JohnSutton, Texas Water Development Board; Dana Porter, The Texas A&MUniversity System Agriculture Program; and Elaine Smith, EnvironmentalDefense, Austin.

This document printed on paper with 25% recycledand post-consumer-waste content.

http://www.environmentaldefense.orghttp://twri.tamu.edu

A Survey of EfficientWater Use Strategiesfor Texas

Texas faces a formidable challenge in meetingthe water needs of its citizens as its populationdoubles over the next fifty years. To meet thischallenge and to provide necessary flows of waterfor the environment, Texas will need to rely uponwater conservation and alternative watermanagement strategies.

But first, policy makers and interested citizensneed to be made aware of the available options tomeet these challenges. This paper will presentsome alternative conservation and watermanagement strategy options, the challenges ofimplementing them, and their overall costs andbenefits.

The State’s current dependable water supplywill meet only about 70 percent of projecteddemand by the year 2050. New water supplyprojects such as reservoirs are expensive, maytake decades to build, and can have detrimentalimpacts on the environment. Waterconservation—making more efficient use ofexisting water resources—can be a less expensiveand less disruptive way of meeting water needs.

Already baseline water conservationassumptions for Texas are projected to result in a22-gallon per capita per day (gpcd) savings in2050 over current rates of municipal water use.This projection translates into an avoided supplyrequirement of 976,000 acre-feet/year by 2050,according to the Water for Texas 2002 State WaterPlan.1 This equates to about 12.4 percent of Texas’water needs. An additional 6.0 percent of needswill be met through water reuse.

But most of the projected water savings calledfor in the State Water Plan result from theimplementation of existing regulations that callfor more efficient plumbing fixtures. This reportwill discuss a wide range of additional waterconservation and efficiency measures that areavailable. If implemented aggressively, thesemeasures can make a significant impact onmeeting Texas’ future water needs.

Water-Use Sectors

When discussing water-use efficiency, it iscustomary to divide water users into threesectors—domestic; industrial, commercial andinstitutional; and agricultural—each with its ownpossibilities for improved water-use efficiency.Although agriculture now accounts for more than60 percent of water use in Texas, this percentage isprojected to decline to about 43 percent in the 50-year planning window.1

With the Texas population shifting from ruralto urban areas, and with the migration of peoplefrom other states to Texas cities, urban demandswill increasingly compete with agriculturalinterests for the same water (figure 1). Forinstance, in the Lower Rio Grande Valley,irrigation districts deliver water to both farmersand cities, but in the event of a shortage, themunicipal users have precedence. Competition forshared water may become contentious, as thepopulation of the Lower Rio Grande Valley isprojected to increase 70 percent within the next 50years.

Tools to Promote Water-Use Efficiency

Within each sector there are many individualpractices to increase the efficiency of water use.For all sectors, three tools can help encourage therespective populations to use water efficiently.First and foremost is an effective outreach andeducation effort. In fact, the first step towards thesuccess of any demand management or waterconservation program is achieving support of theaffected consumers.

An effective outreach campaign can involveutility bill stuffers, media outlets, public events,and speaking engagements. In addition tocreating knowledge of water efficiency practicesamong citizens, an outreach campaign canfacilitate public acceptance of the two other tools:financial incentives and regulatory programs.

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Figure 1. Texas projected water use by sector.

Financial incentives can reward efficient waterusers with rebates or send a warning in the form ofa price signal to water-wasters. The most commondisincentive implemented by water utilities is anincreasing block structure, in which high-volumewater users pay a higher per-unit price for wateruse above set threshold levels.

Finally, regulatory tools, including plumbingfixture rules and landscaping ordinances, may bean appropriate way of producing water savings.

Water Efficiency and Drought Management

At this point, it is worth drawing the distinctionbetween water-use efficiency and droughtmanagement. Water-use efficiency refers to apermanent behavioral change or application oftechnology that changes the baseline level of wateruse. Drought management practices are enacted inresponse to an emergency in either water supply or

water capacity. Water supply is the volume of rawwater available to a population. Capacity refers to awater utility’s treatment and distribution capability.Focusing on drought after it arrives forces watermanagers to react to immediate needs with costlyremedies to balance competing interests in acharged atmosphere.

It has been the experience of many Texas citiesthat water use increases as soon as droughtmanagement restrictions are lifted, causing what isknown as the “hydro-illogical” cycle. The hydro-illogical cycle refers to the phenomenon in whichdrought management measures may induce afeeling of denial among citizens, who return withrelief to wasteful water consumption oncerestrictions are lifted.

On the other hand, wise water use practices area win-win situation: reducing demand on a naturalresource, reducing water bills, and avoiding thecapital costs of building more water utility capacity.

0.0

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1990 2000 2010 2020 2030 2040 2050

Agricultural Municipal Industrial

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Domestic and municipalwater-use efficiency

Figure 2. Mean per capita residential indoor wateruse, 69.3 gpcd . Adapted from Residential EndUses of Water, AWWARF, 19992.

Municipal water use will increase from 25percent of the state total in 2000 to 35 percent by2050.1

Indoor and outdoor domestic water use followssomewhat predictable cycles throughout the year,with a sharp peak in the summer monthsattributable to landscape irrigation.

Outdoor landscape irrigation is responsible forthe peak demand which often strains a utility’scapacity and infrastructure. It follows thatirrigating in the most efficient, science-basedmanner would benefit both homeowners and theutilities serving them.

Indoor domestic water use

Average indoor water use in a single-familyresidence in the United States is 69.3 gallons percapita per day, as broken down in figure 2.2

Although most indoor domestic use isnondiscretionary—cooking, cleaning—there existbehavioral and technological methods to reduceindoor water use. Hardware measures, once installed,easily achieve long-term water savings since theyenable passive savings: they reduce the amount ofwater use to accomplish the same function with noongoing effort. Behavioral changes, such as thoselisted in the box on page 7, cost consumers nothingbut can also result in substantial water savings.Common low-volume appliances include the 1.6-gallon-per-flush toilets, 2.2-gallon-per-minute faucetaerators, 2.5-gallon-per-minute showerheads, andhorizontal-axis washing machines.

In 1991, Texas adopted the Water SavingPerformance Standards for Plumbing Fixtures Act,which established low-flow performance standardsfor plumbing fixtures sold in Texas—toilets, urinals,showerheads, and faucet aerators. The EnergyPolicy Act of 1992 mandated plumbing efficiencystandards nationally, including the 1.6 gallon-per-flush ultra low flush toilet.

This legislation has produced dramatic watersavings. For example, replacing a conventional 3.5-

gallon-per-flush (gpf) toilet saves 1.9 gpf or 54percent. Some older toilets use as much as 5 to 7gallons per flush.

Studies by the Metropolitan Water District ofSouthern California revealed water savings of 29gallons per day for replacement of one toilet in asingle-family residence and a second retrofit savedan additional 17 gallons per day.3

A study by the Texas Water Development Boardestimated an amortized cost of $400 (includingprogram and staff costs) per acre-foot of watersaved by a utility-sponsored program of single-family home toilet retrofits.4

If these savings held true in Texas, installingultra-low flush toilets in new construction andreplacing conventional fixtures in existing homeswould save 840,000 acre-feet per year, enough toserve the needs of 8,300 persons.

Toilets (26.7%)

Clothes washers (21.7%)

Faucets (15.7%)

Leaks (13.7%)

Dishwashers (1.4%)

Shower/bath (16.8%)

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• public information programs,• school educational programs,• residential water surveys,• landscape rebates and educational programs,• rainwater harvesting incentives,• submetering,• graywater reuse.

Education and Outreach

The success of every demand managementeffort, even incentives and regulatory measures, isdependent upon a conscientious public relationseffort via the media, bill stuffers, public events andfairs, speeches to civic organizations, and publicinformational meetings to ensure citizen support(figure 3).

In response to droughts in four of the past fiveyears, almost every water utility in the stateengaged in some type of public informationcampaign. San Antonio Water System (SAWS), forinstance, has achieved a relatively low per capitausage through a multipronged media approach thatinvolved television and radio advertisements; billstuffers; booths at public gatherings; such as theStock Show and Rodeo; a speaker’s bureau; and aturfgrass evapotranspiration project.

Bill stuffers are a cost-effective means to reachevery ratepayer. The cost of public events varies;for instance the Texas Trail Tent at the San AntonioStock Show and Rodeo cost a total of $40,000, orabout $0.30 per contact for the more than 130,000spectators.5

The City of Houston’s conservation plan expectspublic education to provide 47 percent of watersavings over the next 50 years, exclusive ofunaccounted-for water. Elements of the city’spublic information campaign includeadvertisements in the mass media, educationprograms such as Major Rivers and Learning to beWater Wise & Energy Efficient, home water auditkits, presentations to civic and environmentalassociations, and a T-shirt design contest. In thecost-benefit analysis, cost categories are labor,expenses, incentives, and one-time setup costs.Benefits from conservation include current savingsin operations and maintenance and savings fromdeferral or cancellation of capital projects.6

A 1999 Water Conservation Program NationalBenchmarking Survey conducted by the City ofAustin Planning Environmental and ConservationServices Department, found that public educationprograms were almost universal across the 34 largeutilities in the United States and Canada: 94 percentof respondents reported community education

Outdoor Domestic Water Use

Outdoor landscape irrigation accounts for asmuch as 60 to 70 percent of a typical residentialcustomer’s water use in the summer, and isresponsible for peak summer demand. Waterutilities and their customers can save money byreducing the peak, which allows the utility to deferor avoid building excess capacity to meet demandthat occurs only a few days or weeks within theyear. The capacity built at great expense to meetpeak demand often sits idle most of the year.

With careful attention to plant need-basedirrigation practices and irrigation systemmaintenance, landscape irrigation can be cutdramatically while maintaining a healthylandscape.

Water Use-Efficiency Practices

Texas’ water suppliers rely upon a creative arrayof conservation-promoting practices to achievedemand reduction among their residential customerbase, including—

• high-volume price disincentives,• system water audits; leak detection and repair,• ultra-low flush toilets, showerhead, and faucet

aerator retrofit programs,• horizontal-axis high-efficiency clothes washer

rebates,• landscape irrigation audits,• water waste ordinances and enforcement,

Efficient Water Use for Texas: Policies, Tools, and Management Strategies

Figure 3. Public education campaigns can use billstuffers, the print and broadcast media, billboards,booths at public events, and even unconventional —yetpractical—media, such as this bench in Corpus Christi.

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Indoors

• Fix leaks; a slow, steady drip can waste350 gallons per month.

• Install low-flow faucet aerators andshowerheads.

• Insulate hot water pipes to avoid longdelays waiting for the water to “run hot.”

Bathroom—

• Install low-flow showerheads.• Install low-flush toilets, or displace

water in tank with toilet dam.

• Install early-closure flapper.

• Take shorter showers.

• Turn off water while brushing teeth orwhile soaping up in the shower.

• Capture“warm-up” water forhouseplants.

Kitchen—

• Wash only full loads in the dishwasher.

• Rinse vegetables in a pan rather thanunder a stream of running water.

• Keep a pitcher of water in therefrigerator.

Laundry—

• Wash only full loads.

• Consider replacing clothes washer with afront-loading machine.

Outdoors

• Irrigate lawn deeply and infrequently.

• Mulch gardens.

• When cleaning walkways anddriveways, don’t use water from a hosein place of a broom.

• Install rainbarrels or a rainwaterharvesting system for outdoor irrigation

• Replace turf with water-efficientlandscapes.

Domestic and municipal water-use efficiency

efforts to raise public awareness of waterconserving techniques.

Water conservation professionals have learnedthat it is important to present a unified message tothe public. Conflicting and confusing wateringschedules, for instance, have the effect ofoverwhelming ratepayers. Also, droughtmanagement stages between overlappingjurisdictions (such as the Edwards AquiferAuthority and San Antonio Water System) andadjacent jurisdictions (such as the smallercommunities surrounding a major metropolitanarea) should be coordinated.

Outreach and education (nonprice) programsappear to be more effective if the water utilityachieves a “critical mass” of programs. In a studypublished by the American Water Works ResearchFoundation, an increase in the number of nonpriceconservation programs from five to ten options isestimated to reduce demand by 13 percent.Nonprice programs also achieve the desiredobjectives without the political consequences of arate increase.8

Demand management

Many water utilities are making a fundamentalshift from conventional supply enhancement todemand management. In other words, instead ofcasting the net farther for new water supplies,water suppliers are trying to induce customers touse existing supplies more wisely. As noted earlier,lowering the summertime peak demand defers oravoids the expensive prospect of building newcapacity to meet the high demands of relatively fewdays per year.

According to water conservation consultantAmy Vickers, “An important assumption associatedwith incentive strategies is that increased waterefficiency is an equal substitute for water supplycapacity and has equivalent value in themarketplace.”9

At the disposal of water suppliers is an array offinancial incentive and disincentive tools to effectdemand management. These tools can be roughlydivided into price disincentives and rebate or creditprograms.

When it comes to encouraging customers toinstall water-saving appliances, there is no lack ofcreativity in the state as Texas water suppliers offera virtual smorgasbord of rebates, discounts, andgiveaways.

Plumbing fixtures. After the Energy Policy Actof 1992 mandated that only water-conserving

Water: It’s WorthUsing Wisely

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Figure 5. Front-loading horizontal-

axis clotheswashers conserve

water by tumblinglaundry through a

small volume ofwater rather than

by filling a tub.Many Texas cities

offer rebates onpurchases of these

appliances.

exchange project by paying nonprofit groups toperform the actual replacement.

eClothes washers. Horizontal-axis clotheswashers (figure 5), use about 40 percent less waterper load than conventional vertical-axis appliances.Although standards adopted in 2000 by the USDepartment of Energy address energy use ratherthan water use, more water-efficient machinesachieve some of their energy savings by using lesshot water. The retail purchase price of theseappliances, however, is generally higher than thatof conventional clothes washers. To partially offsetthis difference and to boost the market for suchmachines, a few Texas urban utilities—the City ofAustin, SAWS, Bexar Metropolitan Water System,and El Paso Water Utilities—offer rebates on thepurchase price. Under an initiative funded by theUS Department of Energy, the City of Austin wasable to not only arrange to sell these appliances at adiscount through participating retailers, but also tooffer two rebates: one from the water utility and anenergy rebate through the electric or gas utility.SAWS implemented a similar dual-rebate program:SAWS offered $100 per washer and the city’selectric utility offered $100 for each machinepurchased. SAWS estimates the washer rebateprogram saved 271 acre-feet of water, at a cost ofabout $600 per acre-foot.10

Rebates for rainwater harvesting. The City ofAustin offers rebates up to $500 for a rainwaterharvesting installation to encourage the use ofcollected rainwater for landscape irrigation. InHays County, zoning density rules are loosened forhomes with rainwater harvesting equipment.

Rebates for waterwise landscaping andirrigation audits. El Paso Water Utilities, SAWS,and the City of Austin offer rebates for replacingturf with water-efficient landscapes thatincorporate low-water-use plants and common-sense horticultural practices to save water (figure6).

The SAWS Watersaver Landscape programoffered rebates of $0.10 per square foot forinstallation of an approved waterwise landscape. In2001, the program saved an estimated 314 acre-feetat a cost of $253 per acre-foot.10

Utilities in larger municipalities offer freeirrigation audits to residential and/or businesscustomers to determine efficient water schedules,(figure 7). The City of Austin offers credits to high-volume users who submit to an irrigation audit.Austin also provides discounted rainbarrels.

Graywater reuse. Wastewater from a householdis divided into graywater and blackwater

toilets, faucet aerators, and showerheads could besold in the United States, larger Texas watersuppliers took up the charge to encourage theretrofit of existing appliances.

The City of Austin Water and Wastewater, SanAntonio Water System, and El Paso Water Utilitiescreated programs involving free ultra-low flushtoilets to low-income households and rebates forpurchase of the fixtures to other customers (figure4). El Paso Water Utilities conducts large city-widelow-flow showerhead distributions. The City ofHouston replaced leaking older toilets with ULFTsin a 60-unit low-income housing development,netting a 72- percent decrease in total water use.

In a unique symbiotic partnership in California,a private corporation administers the toilet


Figure 4. Many cities and utilities offer financialassistance or rebates for customers “trading up”from a conventional toilet to a 1.6-gallon-per-flushtoilet. The porcelain is often crushed for road-bedmaterial.

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components. In general, graywater is wastewaterdrained from washing machines, showers,bathtubs, and bathroom sinks. Black water isusually wastewater from the toilet and the kitchensink, due to higher pathogen, nutrient, and solidscontent.

The Texas Water Development Board estimatedthat Texans generate between 30 and 50 gallons ofgraywater per person per day. By 2050, graywatervolume in the state will amount to 1.3 billiongallons. Graywater recycling involves filtering,treating, storing and using nonpotable watergenerated by a household or business for localreuse. Within a residence, graywater is often usedfor outdoor irrigation. Dyed graywater issometimes used for toilet flushing in smallbusinesses, such as those in a strip shopping center.

For outdoor irrigation, the Texas Commission onEnvironmental Quality rules allow discharge oflaundry graywater directly on to the groundproviding that the graywater does not pond, thedisposal area has vegetative cover and limitedaccess, use of detergents with phosphorus areavoided, and a lint trap is installed at the end of thedischarge line. Laundry graywater that has been incontact with human or animal waste must berouted to a sewer or treated by an approved on-siteseptic system.

The Texas State Board of Plumbing Examinersand the Texas Commission on EnvironmentalQuality are continuing to evaluate options for reuseof separated graywater streams, as well astreatment of the entire wastewater stream to aquality suitable for outdoor irrigation. Installationof a domestic graywater reuse system that storesand routes shower and lavatory wastewater fortoilet flushing costs between $1,500 and $2,000. Inmany cases, more graywater is collected than canbe used for toilet flushing, requiring rerouting toother wastewater disposal.

Submetering. Apartment complex owners canrecoup the cost of water used by tenants in threeways: by submetering each unit; by allocation—using an approved formula (usually square footageof the apartment)—to proportionately dividemaster meter bill; or by embedding an amount forwater in the base rent.

In the allocated and nonallocated schemes, thetenants have no financial incentive to conserve, andno quantitative feedback if they try to conserve.The apartment owner simply passes on the bill tothe tenants.

Many water conservation professionals feel thatsubmetering offers a more equitable means ofcharging tenants for water, as well as a more direct

way to effect conservation. With submetering, eachtenant is charged for the water used by that tenant.

A study by a San Antonio Water Systemconservation specialist revealed that when low-flow plumbing fixtures are in place, per capitaconsumption appears to decline with theintroduction of some type of system for chargingtenants for water consumption. The study alsorevealed that the presence of low-flow toilets andfixtures is more important in reducing consumptionthan the method of billing.11

Other. The Plumbers to People program ofSAWS provides plumbing services free of charge tofix leaking plumbing in the homes of low-income,elderly, disabled or handicapped customers.

El Paso Water Utilities has conducted severalmass distributions of free low-flow showerheadsthroughout the city.

Figure 6. Water-wise gardening, following sevencommon-sense principles, yields an attractive, low-maintenance landscape. The landscape shown hereis at the Texas A&M Research and ExtensionCenter in El Paso.


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The Learning to be Water Wise & Energy Efficientprogram combines distribution of low-flowshowerheads and faucet aerators with a gradeschool curriculum focused on water. Already thekits distributed in Texas from the Panhandle to theLower Rio Grande Valley have saved enough waterto fill the Astrodome several times over.

Other appliances. Tankless hot water heaterseliminate the “warm-up” water that is normallywasted waiting for hot water to travel the distancefrom the tank to the end use. Energy Stardishwashers use less hot water in the wash cycle.As with horizontal-axis clothes washers, theseappliances are more expensive than conventionalappliances.

Regulatory Oversight and Implementation

Drought contingency plans. The droughts of1990s convinced Texans that drought contingencyplanning is critical for the sustainability of thestate’s water resources. All water suppliers wererequired by Senate Bill 1 to submit droughtcontingency plans to the Texas Commission onEnvironmental Quality. Almost all municipal planscall for some type of outdoor watering restrictions.

Drought contingency plans typically specifyincreasingly stringent measures in response topredetermined trigger conditions such asgroundwater levels or daily pumping rates. Forinstance, Stage 1 conditions may limit outdoor

irrigation to early morning and evening hours,Stage 2 might restrict irrigation to certain days ofthe week, and Stage 3 may prohibit outdoorirrigation altogether.

Although outdoor watering schedules areusually enacted as part of a drought managementplan, as opposed to a water efficiency effort, severalpoints are worth noting here.

Cities within a geographic area should makeevery effort to coordinate irrigation schedules,thereby sending a unified message to customers.For instance, starting during the drought of 1996, acoalition of 20 Travis and Williamson countymayors agreed to a coordinated regional wateringschedule. In previous years, conflicting schedulesin neighboring cities confused citizens.

Care must be taken in mandating wateringschedules as evidenced by the experience with theodd-even strategy, in which citizens water on aprescribed day determined by the last number ofthe address. Although no scientific studies havebeen performed to determine the effectiveness ofthe odd-even regime, empirical evidence fromseveral Texas cities, including Houston, indicatesthat odd-even actually has the effect of increasingwater use. Some citizens even misconstrued themessage, thinking that they were required to wateron their day. In other persons, the mandatory daysinduces a “siege mentality” in which citizensoverwater their landscapes on their prescribed day.

Water waste ordinances. During the droughtsof 1996 through 2000, Texas municipalities firstrelied on public appeals to encourage adherence todrought stage restrictions, but ultimately resorted

photo courtesy David Smith, Texas Water Audits

Figure 7. Water audits accurately determine sprinklersystem precipitation and efficiency. By analyzingsprinkler performance, soil type, plant type, andevapotranspiration, the auditor can provide thecustomer with an irrigation schedule geared to theneeds of the plant.


Figure 8. Concrete and ashphalt will never grow.Overshooting turf areas is wasteful. Several cities havebanned sprinkler irrigation on narrow turf strips.

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Another requirement for efficient municipalwater use is the establishment of an administrationto manage utility programs. The SAWSconservation program is funded with fees on high-volume water use customers. SAWS activelymeasures the value of the saved water and the costof the program, including staff costs. For instance,the cost per acre-foot of saved water has rangedfrom $13 for public education efforts of the CriticalPeriod [drought] management effort of 2000 to $133for a landscape irrigation system analysis programto $199 for the Plumbers to People program.9

Similarly, the City of Houston’s waterconservation plan considered two financial benefitsfrom conservation: savings in operations andmaintenance expenses and savings from delayingor canceling of capital projects. The conservationplan considered 200 conservation measures beforesettling on 20 with benefit-cost ratios greater than 1.The total cost of water saved was $1.41 per 1000gallons.6

Groundwater districts. Under Texas law,groundwater pumpage is governed by the rule ofcapture; that is, a landowner can pump as muchwater as can be put to beneficial use. Groundwaterconservation districts, however, are state-charteredentities that may regulate well spacing, monitorwell construction standards, set guidelines onwater withdrawal, and issue permits. About 80percent of the groundwater pumped in the state islocated in areas served by 63 water districts.

Special groundwater districts. Senate Bill 1477created the Edwards Aquifer Authority in 1993, inresponse to a suit filed by environmental groupsand the Guadalupe-Blanco River Authoritycharging that the US Fish and Wildlife Service wasnot effectively protecting endangered species thatrelied on stream flows arising from the EdwardsAquifer. The EAA water conservation requirementsinclude reduction in overall pumpage of EdwardsAquifer water from 450,000 to 400,000 per year by2008. This translates to a reduction ofapproximately 28,000 acre-feet per year bymunicipal and industrial users.

The Harris-Galveston Subsidence District,created by legislative decree in 1975, provides forthe regulation of groundwater withdrawals to stemland subsidence. Land subsidence caused bygroundwater pumping flooded and forced theabandonment of entire neighborhoods insoutheastern Harris county. For similar reasons, theFort Bend Subsidence District was created in 1989.

to issuing Class 3 misdemeanor summons whenvoluntary conservation did not achieve adequatesavings. El Paso, with only 8 inches of rainfallannually, prohibits washing a vehicle without apositive shut-off nozzle, allowing irrigation runoffto run into the street, and outdoor watering onother than the assigned days. Watering on thewrong day nets the violator a $137 fine plus courtcosts. Citizens caught watering at the wrong timeor allowing water to run into the right-of-way(figure 8) are fined $112 fine plus court costs.Failure to repair leaks is a $245 fine.

Landscaping ordinances. In light of theexpected population increases and population shiftfrom rural to urban areas, some Texas cities havebegun to consider regulating the types of plants inmunicipal landscapes. The water requirements ofturfgrass species vary widely, from water-thriftyBuffalograss to St. Augustine, which is water-thirsty in the sun and lacks drought tolerance. TheCity of Schertz, located northeast of San Antonio,adopted an ordinance in 1996 requiring that all newlandscape turf be both low-water-use and drought-tolerant.

In the next 50 years, most Texas municipalitiesand other water providers will consider year-roundwater use-efficiency ordinances focused primarilyon outdoor landscape irrigation. Selected water-conserving practices are compared in Table 1 onpage 12. Public perception and the political processform the dual municipal hurdles to passage of anysuch ordinance. As with any other waterconservation measure, success depends on thepublic information effort. For instance, in responseto the drought of 1996, SAWS recruited aCommunity Conservation Committee to extend therange of programs deeper into the community andacross a broader cross-section of water users. Thecommittee, composed of representatives of businessand neighborhood associations, school districts,civic groups, and environmental groups provides aclearinghouse for conservation ideas, evaluates andrecommends programs to the SAWS board, andhelps insure that conservation measures areimplemented in all areas of the community.

A water provider’s first job is to convince thepublic of the importance of using water moreefficiently. Since water has largely been a relativelyinexpensive resource the public perception is thatwater resources are inexhaustible. In addition,citizens feel that unlimited use of water to maintaintheir landscaping is a right they have so long asthey are willing to pay for it.

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Table 1. Potential Water savings from selected municipal practices

1 Savings based on Water for Texas 2002, municipal demand of 4.23 million acre-feet per

year in 2000.2 Based upon domestic per capita demand of 101 gallon per capita per day (gpcd),

Vickers, Amy, Handbook of Water Use and Conservation, 2001.3 Adapted from Beecher Janice A. and John E. Flowers, “Water Accounting for Manage-

ment and Conservation,” Opflow, American Water Works Association, May 1999, andpersonal communication, Pat Truesdale, Water Conservation Direct, City of HoustonPublic Works and Engineering, April 2002.

4 Texas Section, American Water Works Association.5 Adapted from Ash, Tom, “Developing the Irvine Ranch Water District Water Budget and Incentive Rate

Structure,” presented at the 1999 Texas Water Conservation in Landscape Irrigation Conference.6 Assumes outdoor landscape demand of 40% of total domestic demand.

The supply side: unaccounted-for waterMost water-conservation strategies focus on

demand management—reducing customer wateruse. Supply-side conservation, however, can beparticularly effective, since the water distributionsystem is under a utility’s direct control. Also,water savings can be achieved without affectingrevenues—water saved translates directly to costsavings. Utilities can effect water supplyconservation with programs to rein inunaccounted-for water, which includes leaks andwater theft.

Utilities typically use the term “unaccounted-for water” or “unmetered water” to describewater that is not billed. While some unmeteredwater may go toward an authorized use, such asflushing of lines and fire suppression, leaks andwater theft can have a serious effect on a utility’swater supply.

The American Water Works Association, thetrade organization of the drinking water industry,recommends a goal of 10 percent for unaccounted-for water.1

The City of Houston Public Works andEngineering, for instance, battled the burden ofunaccounted-for water as high as 30 percent inApril 2001. By April 2002, however, the city hadsucceeded in reducing the loss to 12.3 percent.2

Leak detection is usually undertaken inresponse to a problem. A water system survey isa preventive measure taken to measurecomponents of unaccounted-for water, authorizedor not. Leak detection is achieved by severaltechniques: cameras in water pipes, noise loggers,water-sound sensors, and transducers.1 Personal Communication, Staff members, City of

Houston Public Works and Engineering, WaterConservation Department.

2 Beecher, Janice A. and John E. Flowers, “WaterAccounting for Management and Conservation,”Opflow, American Water Works Association, May1999.

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13

The San Antonio Water System has one of themost extensive and varied water conservationprograms in the state, with a residential conser-vation effort that combines indoor and outdoordomestic programs.

Passage of SB 1477 in 1993 creating theEdwards Aquifer Authority had a profound ef-fect on water resources planning by the San An-tonio region. The Authority was obliged to reducedraws on the Edwards Aquifer from 450,000 to400,000 acre-feet by 2008. As a result, the SanAntonio Water System created a diverse, far-reaching water conservation effort, encompass-ing retrofits, price incentives, appliance volumepurchases and rebates, and public informationprograms under its residential water conserva-tion umbrella.

Indoor domestic programsTwo of the most successful programs involve

toilet retrofits—replacement of leaky, high-water-volume commodes with 1.6-gallon per flushunits—and the repair of residential plumbingleaks.

Plumbers to People, offered to San Antoniohomeowners who meet low-income eligibility re-quirements, provides for the utility to hire aplumber to fix leaking faucets and broken pipesin the homes of eligible persons. Conventionaltoilets are replaced with new ULFT models. In2001, 885 households were visited by a SAWS-contracted plumber, resulting in an estimated wa-ter savings of between 600 and 800 acre-feet an-nually, at a cost of $328 per acre-foot.

Kick the Can offers SAWS customers a $75rebate for swapping toilets which use 3.5 to 7 gal-lons per flush with ULFTs. SAWS conservationspecialists estimate a savings of more than 7,800acre-feet over the next 10 years, at an estimatedcost of about $300 per acre-foot.

A complementary program, the ResidentialToilet Distribution, buys toilets in bulk and givesthem away to SAWS residential customerhomeowners. The estimated water savings fromthis program is about 85 acre-feet at a cost of $421per acre-foot.

To boost the market for high-efficiency hori-zontal-axis clothes washers, SAWS made volumepurchases of these appliances, which were thensold by retail dealers, under the aegis of the Wash

Right program. After purchase, SAWS custom-ers would be eligible for two rebates: $100 fromthe SAWS and $100 from the electrical utility.The appliances save between 8,000 and 10,000gallons per year per family.

Outdoor domestic programsSan Antonio Water System formed a part-

nership with Bexar Master Gardeners and TexasCooperative Extension to determine the feasi-bility of a Potential Evapotranspiration (PET)-Based Watering Program for Turfgrass.

Potential evapotranspiration is an approxi-mation of the water used by a plant throughevaporation from soil and transpiration from theleaf surface, taking into consideration plant spe-cies, temperature, humidity, wind, and rain.Results of the study revealed that some turf spe-cies performed well at less than 100 percent ETreplacement, and considerably less than the 1inch per week then recommended by Texas Co-operative Extension.

The advantage of a PET-based irrigation sys-tem is better water-use efficiency. Turf—and or-namentals—can be watered according to theiractual water needs, avoiding water waste andrunoff.

The popular Watersaver Landscape pro-gram offers a rebate of $.10 per square foot for aminimum 1,000- and maximum 5,000-squarefoot conversion of conventional landscapes to amore water-thrifty landscape with appropriateturf areas, proper soil preparation and mulch-ing, and hardscapes that allow infiltration ofrainwater. In 2001, Watersaver Landscapessaved 192 acre-feet of water at a cost of $253 peracre-foot.

SAWS also offers a Landscape IrrigationSystem Analysis to flag leaking, broken or mis-aligned sprinkler heads and making run-timeadjustments. The program saved 508 acre-feetof water at a cost of $85 per acre-foot.

Taken together, these programs and aggres-sive leak detection and repair lowered SanAntonio’s per capita water use from 212 gallonsper capital per day in 1984 to 147 gallons percapita per day in 2000.1

1 Strassman, Neil, Fort Worth Star-Telegram, July15, 2001.

SAWS water conservation: the sum of many parts


14

Financial incentives can reward efficient waterusers with rebates or send a warning in the formof a price signal to water-wasters. For instance,the most common disincentive implemented bywater utilities is an increasing block structure, inwhich high-volume water users pay a higher per-unit price for water at set threshold levels. At thedisposal of water suppliers is an array of financialincentive and disincentive tools to promotedemand management. These tools can be roughlydivided into price incentives and rebate or creditprograms.

First, though, a word about municipal waterrates in general. Municipal water rates areexpected to be efficient, revenue neutral, andequitable.1

• Efficiency. Efficient in the economic sensemeans that utility supplies water only so long ascustomers are willing to pay more per unit thanproduction costs. Similarly, customers use orconserve water depending upon whether the costof that water exceeds or falls short of those units’value to other customers, according to economicsprofessor Robert A. Collinge at the University ofTexas at San Antonio. Too often water prices sendan incorrect signal about the true cost of newwater supplies because water utilities average thehigh cost of new water supplies with the lowercost of existing resources. This preventscustomers from realizing the the true economicvalue of conservation.

• Revenue neutrality. Ideally, utilitiesadjust rates such that excessive revenues areavoided. In other words, total water revenuesshould more or less equal total water supplyexpenses.

• Equity. No consumer group should bear aheavier burden than another.

Inclining (or inverted) block rate structure.The most direct signal a utility can use to modifycustomer behavior, of course, is a price signal inthe water bill. Twenty years ago, most waterutilities billed water at a flat rate, or even adecreasing block rate structure, which rewardedhigh-volume users with discounted rates. Nowthe increasing block structure, sometimes with alarge jump between tiers, is implemented to send

a price signal to large-volume water consumers.Many utilities, such as San Antonio Water

System (SAWS), earmark revenues generatedfrom the highest tier of water rates to support thewater conservation education programs.

Consumers, though, are not always readilyresponsive to higher water rates. One studyperformed for the American Water WorksResearch Foundation found that consumers aremore cognizant of their average water price thanthe price of the last gallon used, which probablyaccounts for the short-term inelasticity of waterdemand.2 Since consumers are unaware of thecost of the gallon of water being used, large priceincreases that only affect the last block of waterconsumption effect only small demandreductions. In contrast to gasoline, which is soldat a single, well-advertised retail price for a singlepurpose, water is a commodity with a myriad ofend uses which is billed in sometimes difficult-to-understanc¯units.3

Water Budgets andIncentive Rate Structure

One controversial but progressive approachto water pricing is to allocate water to residenceson the basis of a calculated water budget. Thebudget is the sum of per capita indoor waterdemand plus outdoor water demand. Outdoorwater demand is calculated by a formula usingthe variables of landscape area,evapotranspiration, plant coefficient,precipitation, and irrigation system efficiency.According to Tom Ash, conservation coordinatorfor Irvine Ranch Water District in California, inaddition to efficiency, revenue neutrality, andequity, the hallmarks of an incentive rate structureshould achieve—

• Revenue Stability: The rate structure mustbe set to avoid the decrease in revenue thattraditionally accompanies conservation actions.

• Credibility: The rate structure must havea logical and simple basis.

• Building of a conservation ethic: Flexibilityto deal with drought should be inherent in thesystem.

Financial Incentives


15


• Flexibility. The structure should beadaptable and should address the needs of avariety of customers.

To ensure revenue stability, the Irvine RanchWater District separates the fixed costs ofdelivering water from the commodity costs. Astable revenue stream is ensured by recoveringfixed costs through water and sewer charges.Charges for the commodity of the water itself aredirectly related to consumption.

Low-volume water users actually pay afraction of the base rate, while customers usingexcessive amounts over their calculated waterbudget are charged a higher rate. All customersgroups have similar structures.

A further benefit is that charges for high-volume users also provide a funding mechanismfor conservation plans.

FeebatesA variation on this incentive rate design

proposed by economist Collinge are “feebates,”a tool that would provide rebates to frugal userswith the higher rates charged to wastefulcustomers. In this scenario, the utility determinesan allocation, or water budget. It then sets arevenue-neutral flat rate. Feebates apply whencustomers’ use varies from their allocation, withfrugal customers rewarded with a rebate, paidfor by the higher rate charged to high-volumeusers. Revenue neutrality is achieved because thefees pay for the rebates. Water goes to those whoplace the highest value on it, and low-volumeusers are rewarded for conservation.

Both the Irvine Ranch Water District modeland the feebate model provide a mechanism forrewarding conservation by the most efficientusers, a feature lacking in the standard incliningblock rate structure.

The most contentious part of an allocation/incentive rate structure is determination of thewater budget. Water budgeting would representa “rationing” of water that of necessity wouldrepresent a generalization of optimal water use.

Two major barriers to implementation exist:political and technical.

The political challenges largely involve publicperception. The challenge of convincingcustomers that the water budget is an equitablesolution has deterred at least one Texas utilityfrom adopting water budgets after a year-longstudy. Communities in other states haveabandoned the plan when elected officials shiedaway from supporting establishment of waterbudgets.

The technical challenges involve scientificallycalculating the landscape water-use equation anddetermining lot size.

A water provider setting allocations mustdetermine the equation from which the budget isderived using weather, landscaped area, apredetermined evapotranspiration rate, rainfall,and an estimated irrigation system efficiencyfactor. Landscaped area is probably the mostdifficult variable to determine. Remotely-senseddata or county property records offer twomethods of obtaining such data, but incorporatingdata from a nonhomogeneous service area wouldprove difficult in some cases.

A utility must determine the most equitablemanner of treating different classes of customers;for instance, setting multifamily dwellingallotments in contrast to those of single-familyresidences.

Also, in the Irvine Ranch model, even labelingeach higher consumer use necessitated a delicatepublic information campaign. For instance, thehighest tier of water use was initially labeled“abusive,” which was changed to “wasteful” inresponse to negative customer reaction.

Once in place, administration of the waterbudget or feebate system entails no significantchange in the utility’s day-to-day operations.

1 Collinge, Robert A., “Conservation Feebates,” Journalof the American Water Works Association, 88:1:70(January 1996).

2 Michelsen, Ari M., Effectiveness of Residential WaterConservation Price and Nonprice Programs, AWWAResearch Foundation, 1998.

3 Whitcomb, John, Water Price Inelasticities for Single-

Family Homes in Texas, Stratus Consulting, 1999.

In a water budget or feebate structure, the ”silent hand”of the marketplaceefficiently conserves water without the need for regulation.

16

Economists look at water supply in terms ofrisks and benefits. Instead of building supplyinfrastructure to meet every need in times ofhighest demand, economists consider allowingconsumer preferences to determine the best useof water in the face of water scarcity.

Water utilities have traditionally focused onwater development, management, conservation,and water transfer, usually with the goal ofassuring a risk-free municipal water supply. Tokeep lawns green, bathtubs full, and car washesrunning, water utilities typically size the watersupply system for a worst-case scenario: severedroughts of low probability.

Because water consumers are risk-averse, andalso because water utilities are able to pass on thecost of development to those consumers, thetendency to size the water supply system for thesevere drought contingency remains the industrystandard.

A survey of 72 Texas cities by the Texas WaterDevelopment Board revealed that peak demandin some affluent communities is four times thenormal demand.1

A study by the Department of AgriculturalEconomics at Texas A&M University analyzedoptimal water supply levels by modeling risk inseven Texas communities. The study broached theidea of an alternate approach to the building ofsupply infrastructure to meet any and all waterrequests. The rationale is that in the current

climate of high water development costs, it maynot be sensible to maintain idealistic watersupplies necessary to meet peak demands duringtimes of drought.

Such a strategy would require an assessmentof consumer preferences on the reliability of watersupply. In one simple example, consumers wouldmake decisions between the aesthetics of year-round green lawns and the considerable costs ofnew supply development. In some cases, supplydevelopment is not an option, so meeting allreasonable needs must be accomplished withdemand management.

Aside from the obvious costs of “playing itsafe,” there is the environmental impact. Whenmunicipal water users decrease the risk of watersupply shortfalls, they usually shift risk tononmunicipal users. Obviously, some water usersmust bear the shortfall during droughtconditions. Traditionally, that risk is shifted tonatural, aquatic and habitat systems. Thesesystems are residual claimants, using only waterleft over after humans have diverted water fortheir purposes. Recent public policy, however, hasplaced emphasis on streamflow protection. Oneresult of this policy may be redistribution of riskback to municipal users.

1 Mjelde, James W. and Griffin, Ronald C., Valuing andManaging Water Supply Reliability, research reportfor the Texas Water Development Board, December1997.

Managing municipal water supply risk

17

Industrial, Commercial, andInstitutional Water Conservation

Industrial, commercial, and institutional (ICI)use of fresh water accounts for more than half ofnonagricultural water use in Texas and is expectedto increase 47 percent in the next 50 years.1

In Texas, five industrial sectors (chemicalmanufacturing, steam electric power, petroleumrefining, pulp and paper, and primary metals)account for 81 percent of the 2.67 million acre-feetof industrial fresh water used in Texas.1 (Forpurposes of this paper, steam electric power andmining are included in the ICI total.)

Texas is a national leader in chemical andpetroleum processing. The Houston–Beaumont areaboasts 50 percent of the nation’s petrochemicalproduction and 30 percent of its petroleumindustry. The Coastal Bend area is home to thecountry’s third largest refinery and petrochemicalcomplex. But significant differences betweenregions exist. The newer refineries in the CoastalBend and in West Texas use only half as muchwater per barrel of refined oil as those on the UpperGulf Coast between Houston and Beaumont. Withthe water they do use, these refineries are water-efficient: it is not uncommon for petroleumrefineries to reuse water up to 50 times beforedischarging.

Many factors drive water-use efficiency,including rising water and sewer costs,pretreatment regimens, compliance with dischargepermits, and limited water supplies. Sinceindustries pay for wastewater treatment anddischarge by volume, using less water is nearlyalways economical because it reduces overallwastewater treatment costs. Almost universally, thecost of pretreatment of wastewater and disposalexceeds the cost of potable water. In addition, manywater purveyors offer financial incentives toindustrial customers who make strides in waterconservation.12, 13, 14

As in-plant water treatment technologiesbecome more sophisticated, discharge permits morestringent, and water more costly, older industrialplants may find it increasingly cost-effective to find

ways and means to recycle water in-plant. Withinall categories of manufacturing are opportunitiesfor sequential use of water, with water routed inseries to processes that can tolerate a lower qualityof water.

Water recycling systems can show advantageousreturns on investment. Four semiconductorfabrication plants, for instance, show a payback ofas short as 5 months to 4 years on their waterrecycling strategies.5,13

But the cost of water is only one consideration.Increasingly stringent laws regulatingenvironmental impacts of industrial discharge havealso motivated industries to minimize the amountof effluent leaving the plant. In some cases,wastewater recycling is introduced as industriesstrive to comply with permits, or even to achievezero discharge. In zero discharge situations, allwastewater, after treatment, is converted to a solidwaste by concentration and evaporation, or isreused on site.

A comparison of selected ICI water-conservingpractices is shown in Table 2 on page 21.

Achieving Water Savings in Industry

Case studies and water-efficiency audits showtypical potential demand reductions of 15 to 50percent and payback periods of between one tofours years with hardware changes, according towater conservation consultant Amy Vickers9. Thesehardware changes include—

• use of “captured” water for cooling towerevaporative makeup,

• use of reclaimed water for landscape irrigation,• use of reclaimed water for industrial process

water, where appropriate,• enhancing cooling tower efficiency and

increasing cycles of concentration,• use of recycled water and captured water for

industrial process water,• replacement of once-through cooling apparatus

with either air-cooled equipment orrecirculating water-cooled equipment,

18

• audit of automated sprinklers in landscapedarea,

• use of captured rainwater for landscapeirrigation.,

• retrofit of older toilets in high-traffic areas,• replacement of conventional landscapes with

water-thrifty landscapes.


One of the most practical ways for amanufacturing plant to save water is to usewastewater for other plant applications tolerant oflower-quality water, such as the use of capturedrinsewater for evaporative makeup water forcooling towers.

Capture and use of effluent within a plant orcampus serves to reduce the cost of purchasedwater. The most obvious financial incentive forindustrial, commercial and institutional entities toconserve water is an improved bottom line.Industrial customers pay an average of $6 perthousand gallons for potable water from a watersupplier. Industrial reuse programs can havepayback periods of less than one year, sometimes asshort as six months.

The wide variety of processes and clienteleserved make it difficult to generalize conservationstrategies costs and benefits across the ICIspectrum, even within similar industries orinstitutions. For instance, one refining plant mayuse once-through saline cooling water, another mayrecirculate effluent captured from process water.

Water Audits

For the past five years, staff members of theWater Conservation Division of the Texas WaterDevelopment Board (TWDB) have conducted ICIworkshops targeted variously at the hospitalityindustry, manufacturing plants, hospitals, andschools.

In preparation for the workshops, TWDB staffmembers choose an institution or plant, obtainprevious usage statistics, then perform a site surveyand water audit. Workshop participants learnsimple and complex methods for using water moreefficiently. For example, an audit at a hotel inCorpus Christi indicated a 9-month payback periodfor a conservation program that included automaticshutoffs in sinks, replacement of water-cooled icemachines with air-cooled units, serving water onlyupon customer request, and retrofit of toilets inhigh traffic restrooms. Irrigation audits ofcommercial business landscapes have saved as

much as six inches per year of excess irrigation.

Semiconductor manufacturing:conservation of many streams

Semiconductor fabrication plants are in an idealposition to enact sequential water reuse within theplant. The manufacture of semiconductor wafersrequires prodigious amounts of ultrapure water forrinsing—the production of a single semiconductorwafer requires between 1,600 and 2,400 gallons ofpotable water. Refining potable water into ultrapurewater by reverse osmosis produces a waste streamof reject brine amounting to about 25 percent of theinput stream volume. Most Texas semiconductorfabrication plants have devised methods to clean upa portion of the brine for reintroduction into thereverse osmosis input feedwater.

A sampling of Texas semiconductor plants inAustin, San Antonio, and Dallas, showed a returnon capital investment of between 5 and 7 monthsfor water recycling systems, as described below.

Also, ultrapure water used for rinsing siliconwafers is practical for use in other plantapplications, such as in flume scrubbers, acid wastedrains, and of course, cooling tower evaporativemakeup. In continuing efforts to reduce both waterand sewer costs and to comply with dischargepermits, semiconductor manufacturers vigilantlycapture this process water for use in other plantapplications tolerant of a lower-quality water.

• At SEMATECH, a semiconductor industryconsortium plant in Austin, a water reclamationretrofit showed a 7-month payback for a systemthat recycles reverse osmosis reject (the brinesolution remaining after membrane treatment) tocooling towers, vacuum pumps (for cooling seals)and acid scrubbers for removing vented fumes.

• Motorola’s Austin wafer fabrication plantreclaims 50 percent of reverse osmosis reject—about200 gallons per minute—formerly discharged to thesewer. Motorola modified its existing reverseosmosis system by forcing the reverse osmosisreject through a “looser” nanofiltration system andreturning this product water to a storage tank to berecycled as reverse osmosis feedwater.

• Philips Semiconductor saves 462,000 gallonsper day at its San Antonio site by judiciouslyrouting rinsewater from the wafer manufacturingprocess for repurification and reintroduction asreverse osmosis feedwater, as well as for aciddilution in acid waste drains and in fume scrubbers.As an incentive, the San Antonio Water Systemrewarded Philips with a $1.1 million rebate on pastwater bills.


19

cooling towers increased from three to four cyclesof concentration, they could save about 239 acre-feet of water annually.5

In both programs, the water utility increasecycles of concentration by recommending moreappropriate chemical treatment and automatingblowdown disposal with a conductivity meter.Leaks and malfunctioning equipment are identifiedand corrected. Some smaller systems may becandidates for replacement with air-cooled systems.

Opportunities for conservation atcommercial properties

Commercial operations can apply a myriad ofpractices to conserve water. For instance SanAntonio-based La Quinta Inns implemented anaggressive water conservation program, startingwith a retrofit of faucets and showerheads in its35,000 existing rooms, with new properties fittedwith pressure-assisted low-flow toilets. Toilet tanksare routinely tested for leaks with dye tablets. Inaddition, La Quinta uses a proprietary energy andwater management information system to flagdeviations from normal use patterns. La Quinta hasalso developed an irrigation auditing program forits landscaped areas.

Many hotels and motels give guests stayingmore than one night the option of foregoing freshtowels and bed linens, saving as much as 30 gallonsper room per day. The Renaissance Austin Hotelinstalled an ozone laundry system which reducedwater and energy use by 35 percent. The kitchenremoved the water-wasting garbage disposal andinstead tosses scraps in the trash can.

Many kitchens have replaced ice machines withwater-cooled condensers with air-cooled units. Ittakes about 150 gallons of condenser cooling waterto produce 100 pounds of ice. Conserving orreusing cooling water delivers a rapid return oninvestment. Air-cooled ice machines can save $50 to$100 per month in water costs.

The Texas Water Development Board calculatedestimated payback for several other conservationpractices. For instance, at a conference hotel in SanAntonio, replacing all toilets in public areas withultra-low flush toilets at a cost of $3,250 wouldshow a payback in 2.1 years. At another hotel,installing a $200 solenoid valve in an ice machinewould render an immediate payback and an annualwater savings of 1.9 million gallons per year.

• Several semiconductor fabrication plantsrepurify reverse osmosis brine for reintroduction tothe purification process.

Enhanced cooling tower efficiency

Cooling tower makeup (water added to coolingtower reservoirs to replace and equal volume lost toevaporation or discharged to the sanitary sewer tocontrol concentration of contaminants) forms thebulk of industrial water consumption. Coolingtowers remove heat from air conditioning systemsof large buildings, refrigeration systems of foodprocessing plants, and process heat frommanufacturing plants by absorbing heat from arefrigerant in a closed system. Water used forcooling accounts for about 95 percent of water usedby a steam electric power plant and 55 percent ofwater used by petroleum refining overall.15

Water from cooling towers is lost in two ways:evaporation and blowdown. Evaporation is themeans by which water gives up its heat. Blowdownis the water that is discharged to the sanitary sewerto maintain a concentration of dissolved salts andother materials that will minimize scaling or otherfouling of the tower. By carefully adjusting thechemical treatment in cooling tower water, acooling tower operator can increase the cycles ofconcentration.

By increasing the number of times water isrecirculated through the tower before discharge tothe sanitary sewer, water savings are achieved. Forinstance, a 1,000-ton cooling tower will save 140gallons per minute going from 1.2 cycles ofconcentration to 4 cycles.

By targeting industrial customers with theheaviest consumptive (evaporative) demand forcity-sponsored cooling tower audits, both the Cityof Houston and San Antonio Water System hope tolessen demand for potable water.

The City of Houston is looking to cooling toweraudits to reduce water consumption by 375 milliongallons per year, or about 5 percent of the totalwater savings generated by its comprehensivewater conservation program. For every $1 spent onthe program, the City expects to realize $18.60 inreduced water and wastewater costs.6

Reverse osmosis reject brine, capturedcondensate from refrigeration systems, siliconwafer rinse water, groundwater seeping into below-grade basements, and event captured stormwaterare types of captured effluent that have beensuccessfully used for cooling tower makeup waterin Texas industries and institutions. The City of SanAntonio projects that if all 129 customers operating

Industrial, Commercial, and Institutional Water Conservation

20


Use of reclaimed water

The San Antonio Water System has found thatsome customers are willing to pay the same pricefor reclaimed water as for potable water, becausereclaimed water is not affected by mandatorycurtailment measures.

• Since 1965, Central Public Service, SanAntonio’s gas and electric utility, has primarilyutilized recycled wastewater to cool power plants.Now that San Antonio is making 35,000 acre-feetper year of recycled water available, more andmore cooling towers have come on line, including alarge installation at Brooks Army Medical Centerand a smaller one at Trinity University.

• The University of Texas at Austin has achievednothing short of a paradigm shift with its waterreclamation system. By capturing once-throughcooling water from centrifuges, scanning electronmicroscopes, and even drinking water fountains tobe used for evaporative makeup in cooling towers,the water capture system saves 70 million gallonsper year. Recovered water accounts for 8 percent ofthe university’s consumption, a savings of about $3million annually. Older buildings had to bereplumbed, but specifications for all new buildingsrequired the dual-pipe plumbing infrastructurenecessary for reuse. A network of french drains andsump pumps also collects groundwater from ashallow aquifer for evaporative makeup. TheUniversity of Texas is also studying the use ofcaptured air conditioning condensate, which lacksdissolved solids and salts, for boiler feedwater.

• Southwestern Public Service Company inAmarillo annually conserves about 6 billion gallonsof fresh water by substituting wastewater for freshwater in its cooling towers. Blowdown is sent toirrigate adjacent forage land, figure 9.

• Other steam electric power plants in Denton,El Paso, Lubbock, and Cleburne have been usingtreated effluent for cooling water for years.

• San Antonio’s Trinity University, having builtan irrigation distribution network for reclaimedwater, extended the infrastructure to includecooling towers as an end use.

Reclaimed water and capturedwater in industrial process water

• The Sherwin Alumina plant of Gregory in theCoastal Bend area requires about 9 million gallonsof water per day for refining bauxite into alumina,but does not require high-quality water. The SanPatricio Municipal Water District devised a

resource-sharing arrangement, sending 4 milliongallons per day of blowdown from power plantcooling towers directly to the Sherwin Plant (seestory, page 25). Sherwin also captures stormwater inretention ponds for use as process water to such anextent that its water purchases from the nearby SanPatricio Municipal Water district are driven not byproduction but by rainfall.

• In another public-private partnership, acommercial venture was attracted to a water-scarcearea with the promise of dependable supply ofspecially treated wastewater. In 1988, Fruit of theLoom sought to locate a bleach-and-dye facility inthe Lower Rio Grande Valley, but the large volumeof process water required would have strained boththe limited water resources and the capacity of anytreatment plant in the area. In order to attract thenew industry, Harlingen Water Works System, theHarlingen Chamber of Commerce, and the City ofHarlingen proposed treatment of municipalwastewater by reverse osmosis to serve theprocessing needs of the plant. Since initialinstallation, wastewater treatment capacity hasbeen doubled from 2 million to 4 million gallons perday, and now the factory even returns process waterto Harlingen for reprocessing, figure 10.

Figure 9. Southwestern Public Service in Amarillo usestreated wastewater in cooling towers at its Panhandlepower plants. It sells wastewater from cooling toweroperations to a farmer for forage irrigation.

21

Landscape Irrigation Audits

An irrigation audit measures sprinklerperformance; and identifies sources of irrigationinefficiency, such as broken or leaking systemcomponents, and misaligned spray patterns. Theirrigation auditor tailors an irrigation schedule foreach customer considering types of plants, soil, andclimatic conditions. In addition to a reduced water

bill, the customer benefits from a healthierlandscape and improved nutrient retention.

The City of Houston expects its free irrigationaudit for customers with large landscaped areas tosave 860,000 gallons of water annually.

Tax incentives

• In 1997 Senate Bill 1 extended the sales taxexemption for pollution-control equipment toinclude water-reuse equipment.

• In 1997, Texas voters approved anamendment to the Constitution authorizing taxingentities to grant exemptions from ad valorem taxeson water conservation equipment (30 TAC 17). Thepurpose of the amendment is to ensure thatcompliance with environmental mandates does notincrease a facility’s property taxes.

Regulatory Oversight

Title 30 Texas Administrative Code, Chapter210, Subchapter E. Special Requirements for theUse of Industrial Reclaimed Water provides for thebeneficial reuse of air conditioning condensate,cooling tower blowdown, noncontact coolingwater, wash water from fruits and vegetables,nonprocess stormwater, once-through cooling

1 Adapted from Industrial Water Conservation and Reuse in Texas: The Big Picture, H. William Hoffman, TexasWater Development Board, undated.

2 Assumes retail water cost of $4/1,000 gallons.

3 Adapted from Cost Containment Engineering presentations; increasing cycles of concentration from 3 to 4.4 Assumes landscape irrigation of 20% of ICI total of 1.81 million acre-feet/year.

5 Texas Economic Development Business and Industry Data Center.6 Recommendations from International Technology Roadmap for Semiconductors.

Table 2. Water savings from selected ICI conservation practices


Figure 10. Purplepumps and pipesdesignate recycledwastewater atHarlingen WaterWorks wastewatertreatment plant.After a stringenttreatmentregiment,wastewater ispumped to anadjacent bleach-and-dye plant.

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22

water, and steam condensate. The code exemptsproducers or users of reclaimed industrialwastewater within the boundaries of facility orcompound from the requirement to—

• hold a permit for treatment and disposal• notify the Texas Commission on Environmental

Quality to obtain approval for the use ofreclaimed water

• obtain a permit to use reclaimed water• color-code in purple piping carrying reclaimed

water• post signage warning of reclaimed water at

valves• build reclaim infrastructure to special design

criteriaConveyance within a facility does not constitute a

discharge and does not require authorization. Use ofreclaimed water is permissible after the wastewaterhas been treated in accordance with the producer’spermit and the producer provides for an alternativemeans of disposal when there is no demand for thewastewater.

Chapter 210 also authorizes the use of industrialreclaimed water outside the plant for the followingpurposes: landscape irrigation, athletic field and golfcourse irrigation, fire protection, dust suppression,soil compaction, maintenance of impoundments, andirrigation of nonfood crops.

Clean Water Act of 1972. The primary objective ofthe Clean Water Act of 1972 was to restore andmaintain the integrity of the waters of the UnitedStates. This objective translates into two fundamentalgoals:

• Eliminate the discharge of pollutants into thenation’s waters.

• Achieve water quality levels that are fishable andswimmable.

The Clean Water Act focuses on improving thequality of the nation’s waters. It provides acomprehensive framework of standards, technicaltools and financial assistance to address the manycauses of pollution and poor water quality, includingmunicipal and industrial wastewater discharges.

For example, the Clean Water Act requires majorindustries to meet performance standards to ensurepollution control; charges states and tribes withsetting specific water quality criteria appropriate fortheir waters and developing pollution controlprograms to meet them. The Clean Water Act hasbeen the impetus for ICI water users to reducechemical requirements and waste loads by betterpretreatment systems and more precise use ofchemical treatments, such as in cooling towers.

Under the Texas Pollutant Discharge EliminationSystem (TPDES), the USEPA delegated responsibility

to the Texas Commision on EnvironmentalQuality (TCEQ) for the quality of waterdischarged from those industrial facilities notfalling under the jurisdiction of the Texas RailroadCommission. (After September 1, 2002, the TexasNatural Resource Conservation Commissionchanged their agency name to Texas Commissionon Environmental Quality.) The Texas RailroadCommission regulates water produced as a by-product from oil and gas production.

Barriers to Implementation

A unique workshop organized by TWDB inpartnership with the Texas Chemical Council; theEnvironmental Solutions Program of the Centerfor Energy Studies, University of Texas; and theTCEQ, brought together state, industry, andacademic counterparts to begin a dialog onremoving barriers, and searching for innovativeinstitutional and financial incentives to promoteindustrial water reuse.

The public, utility personnel, and electedofficials need to be made aware of thepossibilities, benefits, science, and risks associatedwith water reuse so that logical decisions can bemade.

• Use of full-cost accounting. Industrial waterreuse costs are more complex than comparing thecost of installing a reuse system versus the cost ofpotable water. Full-cost accounting embodiesother factors—location, infrastructure, communityissues—that may vary between regions and thetype of industry. Although initial retrofits forreuse may be costly, reclaimed water is likely tobe cheaper than future supply alternatives.

• Information sharing by industry. There is aneed to develop “how to” information andeffective ways to trade success stories andmethodologies.

• Organizational issues. If extensive waterreuse is to be implemented, local utilities or waterdistricts will need to be established, and “across-the-fence” issues resolved. That is, will onecompany be able to reuse directly anothercompany’s effluent without its first being treatedto discharge standards.

Regulation, Incentives, and Policies

• Hazardous waste rules sometimesdiscourage water reuse within a facility.According to US Environmental ProtectionAgency regulations, if hazardous waste comesinto contact with water, that water by definitionbecomes hazardous waste and cannot be reused,


23

even if the hazardous waste is undetectable.• Water rights. Water rights holders are

concerned that the water they conserved or reusewill be subtracted from their permit. Texas lawcurrently protects against such loss, but industryrepresentatives still feel this concern needs to beaddressed.

• Establishing financial incentives to encouragewater reuse. The State currently lacks sufficientpolicies supporting training and technicalassistance. Two state-level tax incentives


specifically targeting industrial water reuse are ineffect; however, federal tax incentives remainundeveloped.

• The effect of conservation and reuse ondischarge permits. Concentrations of organic,chemical, plastic, and synthetic fiber in effluentincrease while the volume of water decreases.Possible solutions to this dilemma includeincreased flexibility in the application of rules thataddress in-stream water quality protection and thecalculation of mass limit based on nonconservationflow.

A symbiotic relationship between a heavyindustrial plant, a municipal water district, and apower plant is saving millions of gallons per dayon the north shore of Corpus Christi Bay.

The refining process at the Sherwin AluminaCompany in Gregory needs great volumes of waterto process alumina (aluminum oxide) from bauxiteearth material. The process, which involves achemical slurry pumped in a continuous loop, cantolerate lesser-quality water, including capturedstormwater, treated effluent, and tailings leachate.

When it became apparent more than 10 yearsago that urban competition for raw water from theNueces River might leave the Sherwin plant shorton water, the plant operator, Reynolds Metals atthe time, got creative in finding sources of water.

First, Reynolds built large earthenimpoundments to capture and store rainwater tobe used as process water, which serves as both atransport and extraction medium. The capturedrainwater proved so effective that during aparticularly wet spring, the alumina plant operatedfor 93 days without purchasing water from SanPatricio Municipal Water District. Captured watertrickling through old tailings beds became another“found” source of water. The Sherwin plant pipedin treated effluent from the Aransas Passwastewater treatment plant for dust control on thetailings beds. In what turned out to be a win-winsituation, the effluent has rehabilitated the tailingsbeds to enable them to support plant and bird life,and the percolating water is redirected to the plantfor recovery of dissolved materials.

More recently, a 400-megawatt cogenerationpower plant was built adjacent to the Sherwinrefinery, presenting opportunities for moresymbiotic relationships. Cogeneration refers toputting to productive use the waste heat generated

in steam electric power plants. After pressurizedteam drives turbines in the power plant, the residualsteam is sent to the refining plant, satisfying 100percent of its steam requirements. Sherwin returnsthe spent steam as hot water to the power plant,where it is treated and again used for steam andcooling tower makeup water. In addition, Thepower plant also provides half the electricity neededby the refining operations.

From the plant’s large cooling towers and watertreatment plant, 2 million gallons per day is routedto the Sherwin Plant for use as process water in thecontinuous loop refining process. Ultimately, theentire system results in zero discharge, as Reynoldsdoes not discharge process water or evenstormwater from events up to 9 inches in 24 hours.

At the Sherwin Alumina Company plant inGregory on the north side of Corpus ChristiBay, stormwater is captured in large earthenimpoundments for later use in processingalumina. Tom Ballou, environmental qualitysuperintendent at the Sherwin Alumina Plantis shown.

Coastal Bend refinery: symbiotic relationships

24

Cooling towers, those sometimes obvious,sometimes well-camouflaged industrial hulks,can be huge water wasters. Cooling towers servelarge cooling and refrigeration applications, suchas in food processing and electronics componentmanufacturing plants as well as providing forthe air conditioning of large buildings. Coolingtower water absorbs heat from the refrigerantfluid in a closed system, changing the refrigerantfrom a gas to a liquid. The water then returns tocascade through the cooling tower to lose itsheat. Much water is lost to evaporation in theprocess.

The two largest cities in Texas—Houston and SanAntonio—are seizing the opportunity to helpcustomers more efficiently operate their coolingtowers with utility-sponsored audits. The City ofHouston’s Water Conservation Program initiateda cooling tower audit program with the goal ofsaving 375 million gallons annually, or 5 percentof the city’s total water conservation program.According to the Water Conservation Plan, theprogram is projected to yield a high cost-benefitratio—for every $1 spent on the program, the Cityexpects to realize $18.60 in reduced water andwastewater costs.

Houston Flags Big UsersIn Houston, utility personnel identify cooling

tower customers by scrutinizing the wastewatercredit on their water bills, and have found thatabout half of the City of Houston cooling towercustomers would be good audit candidates.(Cooling tower customers are eligible for awastewater credit, as much of the water is lost toevaporation in the cooling process rather thansent to the sanitary sewer.)

In Houston, the average cooling tower accountuses 500,000 gallons per month, and the auditcontractor projects a realistic goal of improving theefficiency of 250 towers by 25 percent. On the highend, the George R. Brown Convention Center uses4.5 million gallons per month of cooling towermakeup.

In addition to evaporative loss, however, muchwater is discharged as blowdown, an amount ofwater intentionally wasted to control salt and othercontaminants which would cause corrosion,fouling, and scaling of the cooling tower structures.Water in a cooling tower is continually recycled

Cooling tower audits: Going for behemothsfrom a sump. Contaminants become moreconcentrated with each cycle, so a portion of wateris discharged and replaced with fresh water tomaintain an acceptable water quality.

First, the Houston cooling tower audit engineerswill seek to increase cycles of concentration byrecommending more appropriate chemicaltreatment and automating blowdown disposal witha conductivity meter. Increasing cycles ofconcentration has the effect of decreasing theamount of water that must be blown down.

Second, leaks and malfunctioning equipmentwill be identified. Some smaller systems may besuitable for replacement with air-cooled systems.

Although large cooling towers are generallymore efficient and usually more actively managedthan small towers, the consulting engineers mayintroduce operators to the possibility of usingrainwater or air conditioning condensate asmakeup water.

The City of Houston’s Water ConservationProgram’s budget for this project is $208,000 overthe first three years, saving 289 acre-feet annually.

SAWS offers audits SAWS recently issued a request for proposal for

cooling tower audits in San Antonio. SAWS is firsttargeting 129 general class customers eligible forsewer credits due to evaporative loss, as the Cityof Houston has done. These 129 customers accountfor a combined monthly average consumption ofmore than 54 million gallons or about 1,992 acre-feet annually.

For purposes of estimating water savings. EdWilcut, SAWS conservation planner responsible forindustrial programs, figures that if all 129businesses increased from three to four cycles ofconcentration, SAWS could realize an annualsavings of 239 acre-feet, or 12% savings. Coolingtowers in San Antonio run between 2.5 and 4 cyclesof concentration.

Wilcut estimated that there are as many as 500cooling towers in the SAWS service area.

The cooling tower audit will provide thecustomer with a detailed engineer’s report specificto that tower, including recommendations for moreefficient operation for achieving water and energysavings, capture of blowdown water for reuse inother applications, and leak identification.


25

Agricultural WaterConservation

Two trends will create major implications for thefuture of rural Texas: decreased irrigation due todepletion of groundwater resources and increaseddemand for water resources by urban areas.

Irrigated agriculture has historically been thelargest water user in Texas, accounting for almost70 percent of water use during the past fourdecades. Irrigation water demand, however, isexpected to decline by 12 percent in the next 50years, and by 2040 municipal use of water isexpected to surpass agriculture uses.1

Because of population growth and marketforces, water will be drawn to higher-valuedmunicipal uses. Well known are the efforts of waterentrepreneurs who have been actively speculatingin groundwater as a commodity in the High Plainsand in south central Texas.

Agricultural water conservation can assist thestate in meeting the water needs of its growingpopulation while maintaining the productivity ofthe agricultural sector. A comparison of selectedagricultural water-conserving practices is shown inTable 3 on page 30.

Recognizing the importance of the agriculturalsector and the opportunities for increasedconservation, stakeholder groups convened todiscuss the draft 2002 State Water Planrecommended that the state develop policies toensure the sustainability, viability, andcompetitiveness of agriculture.

In the final 2002 Texas State Water Plan, theTWDB proposed the legislature consider thefollowing recommendations—

• Protection of rural community access to waterresources to ensure continued economic viability ofrural Texas.

• New financing mechanisms to supportagricultural water conservation, especially tosupport the conversion of water saved to otheruses.

• Determination of standards for evaluatingimpacts of water rights amendments andgroundwater exports on third parties in rural Texas.

Methods of AchievingIrrigation Efficiency

Water conservation in irrigated agriculture canbe achieved by irrigation scheduling, improvedirrigation system efficiency, enhanced conveyanceefficiency, conservation tillage practices, andeconomic incentives for irrigation suspension.

Irrigation Scheduling. An idea that originatedin the High Plains, irrigation scheduling, has takenhold across much of the state. In the High Plains,farmers have found that, in highly efficientirrigation systems, high-frequency, shorter cycle

Agricultural water conservation canassist the state in meeting the water

needs of its growing population whilemaintaining the productivity of the

agricultural sector.

Rural areas and the agricultural community,with 15 percent of the state’s population but 80percent of the state’s land area, are integral parts ofthe Texas economy as well as its culture. Totaleconomic activity from agriculture brings $75billion to the Texas economy, and 20 percent of thelabor force is employed in agriculture-relatedbusiness. In 1998, farmers used about 10.6 millionacre-feet of water to grow crops on 6.3 million acresof irrigated land. It is worth noting that thefinancial impact of irrigated agriculture is morethan twice that of nonirrigated agriculture. The pastthree drought years since 1998, however, have costagriculture and its associated businesses $4.5 billionin direct losses.16

26


deficit irrigation at 70 percent deficit irrigation(irrigating only 70 percent of replacement waterdetermined by plant needs and potentialevaporation) produces similar cotton yields to 100percent potential evapotranspiration at shorter-period revolutions.17,18

By scheduling irrigation to closely match acrop’s needs by using potential evapotranspirationdata referenced to the crop, farmers can producemaximum yield per unit of water. Irrigationscheduling relies on networks of weather stationsfor evapotranspiration data, often referred to as“ET networks.” To assist farmers with developingaccurate irrigation schedules for their fields, fourweather networks targeted to agriculture have beendeveloped.

Of benefit to all farmers, evapotranspiration(ET) networks also enhance water management byurban landscapers, golf course superintendents,and even home gardeners.

Weather data from the 21 stations of the widest-ranging Texas ET19 network (http://texaset.tamu.edu) can be accessed on the web sitefor weather information, evapotranspiration, andcrop watering recommendations of the AgricultureProgram of the Texas A&M University System.

Two other networks on the High Plains, onebased in Lubbock and the other in Amarillo, havejoined forces to operate more than 20 ET weatherstations in the Panhandle. Each night, the networksautomatically fax PET and other crop data tosubscribers and post the data on the web site. Bothnetworks use the same nationally standardized ETequation and crop coefficients.19 Other networksrely on international generalized crop coefficients.Crop coefficients for specific crops are multipliedby reference ET to calculate crop waterrequirement.

The South Plains ET network can be accessed athttp://lubbock.tamu.edu/irrigate/et/etMain.html.The North Plains ET Network can be accessed athttp://amarillo2.tamu.edu/nppet/petnet1.htm.

A fourth network of 22 stations is based at theCorpus Christi Agricultural Research andExtension Center.

Irrigation System Efficiency. There is greatpotential to reduce the need for irrigation water byimproving the systems used to deliver water to theplants. Two major variables affect irrigation systemefficiency: application efficiency, a function ofevaporation and runoff; and distributionuniformity, a function of the mechanics of theirrigation system.

Compelled by the incentive of lower operationalcosts and a favorable return on investment onequipment, Texas farmers continue to embrace newtechnology and best management practices tooptimize the use of irrigation water. Farmers areable to adopt water-efficient practices using theconstantly expanding universe of irrigationtechnologies.

In the High Plains, farmers are clearly aware ofthe need and the advantage of conserving—nearlyevery one of more than 16,000 center pivots usehighly efficient technology with the sprinklernozzles installed on drops closer to the ground.About 80 percent of new center pivots use thistechnology, which yields a 95- to 98-percentefficiency (figures 11 and 12). The primary hurdle ofupgrading from a less-efficient irrigation system toan efficient one, of course, is the cost. The cost ofinstalling a quarter-mile low-energy precisionapplication center pivot sprinkler is about $35,000to $40,000, with the return on investment a functionof energy costs.

The crop itself sometimes determines irrigationtechniques. For instance, in the Lower Rio GrandeValley, where high-valued crops such as melons areproduced, farmers find that using relatively costlydrip irrigation and plastic mulch gets their productto market earlier and with better quality, thereforefetching a higher price.

Irrigation Conveyance Efficiency. Urbanpopulation in the Lower Rio Grande Valley isincreasing at a higher rate than almost anywhere inthe state, and is expected to grow by almost 230percent in the next 50 years. Agriculture now

Figure 11. Low-energy precision application (LEPA)center pivot systems can achieve efficiencies as high as95 to 98 percent.

27

accounts for nearly 90 percent of total water use inthe region, but municipal and industrial use isexpected to increase by 220 percent, or from almost15 percent to 40 percent of total water use,according to Texas Water Development Boardprojections. Since water supply in the region isfinite, some degree of transfer of water rights willbe required.20

In the Lower Rio Grande Valley, virtually allwater used is surface water. The 28 active irrigationdistricts deliver water to both farmers and tomunicipal water districts via a network of 1,460miles of irrigation canals. In times of scarcity,however, the municipal interests have precedence.

A study by Texas Cooperative Extensiondetermined that rehabilitation of Lower Rio Grandeirrigation canals and laterals could save almost160,000 acre-feet in a drought year and almost211,000 acre-feet in a normal-rainfall year (figure13).

Reducing conveyance losses could involve acombination of canal lining to reduce seepage,installation of nonleak gates, replacement of opencanals with pipelines, and spill loss reduction. Theaverage conveyance efficiency in the 28 districts is71 percent.

Construction costs and water conserved under asimilar program undertaken by the ImperialIrrigation District in California showed a range of$37 to $132 per acre-foot of water saved in 1988dollars.

Conservation Tillage. Conservation tillage is afarming practice that leaves the stubble from theprevious crop on the surface of the field. Plowingduring the growing season is kept to a minimum(figure 14).

For generations, farmers tilled the soil at least 4inches deep 9 to 11 times per growing season withplows powered by mules, oxen, or tractors.Conventional wisdom determined that plowingbroke up the soil in preparation for the next crop.Using conservation tillage practices, the number oftillages would be halved, or less. The stubble acts asa mulch to retain moisture to keep the soil cooler, toinhibit weed growth, and to lessen the erosiveeffects of rainfall and wind erosion. More organicmatter gives better soil permeability and waterholding capacity.

Conservation tillage has been shown to save oneirrigation per growing season.

One test of conservation tillage near CorpusChristi by Texas Agricultural Experiment Stationresearchers showed a 37-percent increase in cottonyield over a conventionally tilled field.

Plant Breeding

Researchers worldwide are studying plant–water relations at several scales to develop cropvarieties that stand up to water deficit. It has longbeen known that crop cultivars vary in their abilityto produce under limited water supply. Texas hasthe technology and scientific personnel to increasedrought-tolerance and water-use efficiency in itsmajor crops: cotton, corn, sorghum, and wheat.Drought tolerance is the ability of the plant to

Agricultural Water Conservation

Figure 12. Furrow dikes retain water to allow more timefor infiltration. Furrow dikes are an integral part of thelow-energy precision application system.

Figure 13.Improvements tocanals such as thisone in the LowerRio Grande Valleywill mean a netincrease inavailable water dueto lessenedconveyance losses.

28

recover from a period of low irrigation. Water-useefficiency refers to the crop’s ability to produceunder a regime of deficit irrigation. Plant breederscreate hardier cultivars by finding existing plantswith drought-tolerant or efficient water usemechanisms, then introducing these traits into cropvarieties.

A coordinated effort to identify and breedcultivars better adapted to low water supply couldhave enormous economic benefit for relativelyminor additional investment in support personnel,equipment, and operating expenses.


Due to the fact that agriculture is a business, thebottom line is the most compelling reason forfarmers to reduce water use. In the case of

groundwater, if less water is pumped, less fuel andoperational and maintenance costs are incurred.Because agricultural water conservation can makewater available to people and the environment,State support for conservation practices isappropriate.

Loans for water-conserving farm equipment.The Texas Agricultural Finance Authority wascreated in 1987 as a unit of the Texas Department ofAgriculture to provide financial assistance throughlending institutions to producers and providers ofgoods and services in rural areas. The LinkedDeposit Program provides commercial loans atbelow-market rates of up to $250,000 for water-conserving equipment or projects.

The Texas Water Development Board grantswater districts up to 75 percent of cost toward thepurchase of equipment to evaluate or demonstrateefficient agricultural water uses on privateproperty. The Board also loans funds to districts forpurchase and installation of water-conservingequipment on private property.

Market-Based IncentivesDry year option. Irrigation suspension

programs offer an economic mechanism fortemporarily shifting water from agricultural use tohigher-valued uses. In this set-aside program,farmers are offered compensation for abstainingfrom irrigating crops in dry years. Depending uponthe stage of the growing season when the dry-yearoption is offered, farmers can pursue severalalternative courses of farming practices. Early inthe season, crop mixes can be changed to moredrought-tolerant crops. Later, crops can beabandoned or managed using deficit irrigation ordryland farming techniques. Because watershortages are an intermittent event, utilizing dryyear options as part of standard droughtcontingency plans can be a much more cost-effective way of meeting water needs than buildingnew reservoirs.

Irrigation suspension programs. The optimalapplication of water marketing would provide ameans for cities to provide financial assistance foragricultural water conservation. The farm wouldremain in production, and the cities would acquirethe saved water. Some portion of the saved watercould be left in the stream to provideenvironmental flows. In some Western states, thewater rights are transferred in perpetuity. Thereexists, however, a need for short-term transfers,such as irrigation suspension programs, due to thefluctuation of water supply and theunpredictability of drought year

Figure 14. Conservation tillage beats plowshares.Conservation tillage, which residual from aprevious crop serves as mulch, has proved morewater-efficient than traditional tillage on cotton,corn, and grain sorghum. Shown here is JoeBradford of the Agricultural Research Service inWeslaco.


29

Agricultural Water Conservation

planted at ultranarrow row spacing produce thesame yield with 45 percent less water in thisparticular study (figure 15).

Many variables—soil type, climate, irrigationtechniques, cultivation practices—affect watersavings, so it is worth noting that results of studiesare site-specific.

Local cotton growers are invited to tour thedemonstration plots at the Fort StocktonAgricultural and Extension Center’s annual fallcrops tour.

Texas farmers embrace proven technologies andmethods to effect water conservation. Ongoingresearch will continue to boost productivity usingless water. On the horizon are advances in precisionagriculture: interpreting satellite imagery to makeirrigation decisions; drought-tolerant plantgermplasms; and radio- or telephone-controlledautomated irrigation systems.

While Texas has made important strides inresearching agricultural conservationopportunities, providing outreach and educationservices, and instituting agricultural loan programs,the full potential for water savings has yet to berealized.

The Edwards Aquifer Authority implemented apilot irrigation suspension program in 1997 onnearly 10,000 acres in Medina and Uvalde countieswith the objective of increasing springflow atComal Springs and providing relief tomunicipalities during drought. Although 1997turned out to be a wet year, based uponcalculations with historic pumping rates, hadconditions been dry in 1997, suspending irrigationon acreage would have reduced pumping by 23,206acre-feet at a cost of about $99 per acre-foot. Thisrelatively high price might be due to severalfactors, including lack of experience with anirrigation suspension program, late start-up,tendency to bid high enough to compensate for aworst-case scenario.21,22,23

Education and Outreach

The Texas A&M University System (TAMUS)Agriculture Program transfers knowledge to theproducer. Dedicated to a 125-year land-grantresponsibility, the TAMUS Program has beenserving the agricultural community by distillingresearch results for efficient water use technologiesinto practical real-world applications, delivered bya wide-ranging network of county extensionagents.

County agricultural extension agents andextension specialists transfer new knowledge andtechnology on more efficient cropping to producerswith annual field days, on-farm and pilotdemonstrations, seminars, conferences, televisionand radio broadcasts, and newspaper columns.Research and extension activities take place at 14research and extension centers, in 250 countyoffices, and in 12 district centers. Each year, TexasCooperative Extension makes more than 17 millioneducational contacts.

For instance, Texas produces more cotton thanany other state, but this abundance is due to a vastland resource. Limited seasonal rainfall andgroundwater reduce yields to among the lowest inthe country. TAMUS Agriculture Programresearchers are investigating ways to increasecotton yield, such as more efficient irrigationscheduling technology, subsurface drip irrigationand low-energy precision application center pivots,drought-tolerant crop germplasms, and improvedcropping techniques.

County agents in Pecos County installed ademonstration plot showing an improved croppingtechnique at a privately-owned farm. Yields at thedemonstration plot indicated that highly efficientsubsurface drip irrigation system and cotton

Figure 15. Cotton farmers in Pecos County tour ademonstration field planted with various rowwidths and planting patterns. Ultranarrow rowshowed better yield than wider-spaced rows in thisstudy at a demonstration plot.

Conversions1 acre-foot 325,851 gallons1 million gallons 3.07 acre-feet1 acres 43,560 square feet100 cubic ft 748 gallons1 million gal./day 1,121,000 acre-feet/yr1,000 square feet of collection area yields 625gallons/inch rainfall

30


Table 3. Water savings from selected agricultural conservation practices, Texas cotton1

As project manager for the City of RomaEconomically Distressed Area Program(EDAP), a Texas engineering firm, TurnerCollie & Braden, found an innovative solutionto the city’s water needs. The engineering firmproposed that the $2.8 million available to theCity of Roma through EDAP to purchase waterrights be instead used to fund improvementsin irrigation canal conveyance efficiency withinCameron County Irrigation District No. 2. Theirrigation district could then transferapproximately 4,100 acre-feet of “saved”agricultural water rights to the City of Roma.

The City of Roma needed majorimprovements to its water and wastewaterfacility to bring its system into compliance withstate standards, to provide service to theresidents of existing colonias, and to meetfuture needs. Overall, the plannedimprovements would serve approximately20,000 people. TWDB financing for the planned

improvements was contingent upon the City ofRoma acquiring additional water rightssufficient to meet project demands. (Coloniasare economically distressed subdivisionslacking state-approved water supply andwastewater collection systems.)

Since irrigated agriculture is a majorcomponent of the economy of the Lower RioGrande Valley, it was important to maintainsupplies needed for agriculture while makingadditional water rights available for conversionto municipal and industrial uses.

This exchange of “conserved” watersatisfied the city’s need for more water withoutimpacting agricultural irrigation water. In fact,rehabilitating irrigation canals would saveabout 4,900 acre-feet annually, leaving thedistrict with a net gain of approximately 800acre-feet per year. Through conservation,agricultural land was not taken out ofproduction to sell water rights.

Irrigation district swaps water rights for rehab

1 From National Agricultural Statistical Service, in 2001, 2,238,000 irrigation acres of Upland cotton in Texas.2 From Amosson, et al, Economics of Irrigation Systems, Texas Cooperative Extension, December 2001.3 Effective efficiency is defined as the volume of irrigation water beneficially used/volume of irrigation

water applied x 100.4 Water savings calculated using microirrigation as the standard.

Note: Water savings quantities are for illustrative purposes only. It is difficult to derive accurate agriculturalwater savings as no single data base exists with the necessary information, no statewide records are kept onthe irrigation types used on farms, and there are no statewide figures on actual water consumption on an on-farm basis. Also, the water savings from the table are not additive; if a farmer were to implementmicroirrigation, he would not also implement LEPA.

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31

• Senate Bill 1, the omnibus water planning billpassed in 1997, requires that reuse be consideredin all future water resources planning and thataddresses certain water rights issues relating toreuse. This legislation mandated that alternativewater strategies, such as desalination and weathermodification, be considered as part of the state’swater management policy.

• Senate Bill 1 also expanded the sales taxexemption for pollution control equipment toinclude water-conserving equipment formanufacturers.

• Senate Bill 1 allows the Texas WaterDevelopment Board to use principal from theAgriculture Trust Fund to provide financialincentives and/or low-cost loans for the installationof water-conserving devices.

• Senate Bill 2 establishes a framework forsupporting alternative water strategies, such asdesalination, brush management, weathermodification, and water conservation and droughtmanagement projects.

• Senate Bill 2 offers a sales tax break onequipment whose primary function is waterconservation, including rainwater harvestingequipment, equipment for water reuse,conservation, and desalination.

• Senate Bill 2 also expands the list of water rightsthat cannot be canceled for nonuse due to waterconservation. If an entity reduces water use due toconservation, that portion of reduced use cannotbe cancelled under the use-it-or lose-it cause underwater rights.

• The revision of Texas Commission onEnvironmental Quality water reuse rules underChapter 30 Texas Administrative Code (TAC) 210to allow utilities and industries to provide waterfor reuse without having to amend wastewaterdischarge permits.

• Development of rules in 30 TAC 285 governingon-site wastewater treatment systems that allow forreuse.

• HB 2401 adds water conservation to the typesof projects local governments can enter into; forexample, the Education Code is amended to allocateincentive funding for achievement of waterconservation goals by institutions.

• HB 3286 makes water conservation projectseligible for performance contracting as a separateitem by extending existing legislation pertaining

only to energy conservation. In a performancecontract, a company enters into an agreement withan entity to provide up-front capital to pay forimprovements resulting in water or energysavings. The company is paid back out of therevenue stream based on conservation savings.

• HB 2403 again piggybacks water conservationon energy-related legislation, requiring clotheswasher manufacturers to report to TexasCommission on Environmental Quality each yearbeginning in 2003. Water savings are achieved viaenergy savings, in that heating less water willresult in decreased energy use.

• Chapter 210 TAC regulates the quality, enduse, restrictions, design, and operationalrequirements for the beneficial use of reclaimedwater, which may be substituted for potable or rawwater..

Financial Incentives• HB 2404 specifies that all new construction of

multifamily after January 1, 2003 be submeteredby unit. Properties applying for a TCEQ permit toallocate water (by apartment size or number oftenants) or to submeter after that date would haveto be audited for leaks, to install low-flowshowerheads and faucet aerators, and mustreplace the highest-volume toilets.

• In 1997, Texas voters approved an amendmentto the Constitution authorizing taxing entities togrant exemptions from ad valorem taxes on waterconservation equipment (30 TAC 17). Thisamendment gives political subdivisions the optionto decide whether the benefits from the waterconserved by the equipment would be morebeneficial than the forgiven tax revenue.

• Equipment for water reuse is eligible forexemption from property taxes under aconstitutional amendment effective January 1,1994, now in the rules as Chapter 30 TexasAdministrative Code. The intent of theamendment was to ensure that compliance withenvironmental mandate did not increase afacility’s property taxes.

• Water conservation equipment. Equipment forwater reuse is eligible for exemption under Title30 TAC 277.

Legislative remedies

32

1 Water for Texas 2002: State Water Plan, Texas WaterDevelopment Board, , May 2001, (http://www.twdb.state.tx.us/publications/reports/State_Water_Plan/ 2002/FinalWaterPlan2002.htm).

2 Mayer, Peter, et al, Residential End Uses of Water,American Water Works Association ResearchFoundation and AWWA, Denver, Colo., 1999.

3 Chestnutt, Thomas W., Anil Bamezai, and CaseyMcSpadden, The Conserving Effect of Ultra LowFlush Toilet Rebate Programs, Los Angeles, Calif.,Metropolitan Water District of SouthernCalifornia.

4 Texas Water Development Board and GDSAssociates, Quantifying the Effectiveness ofVarious Water Conservation Techniques in Texas,May 2002.

5 Conservation and Reuse Award entries, WaterConservation and Reuse Division, TexasSection, American Water Works Association,1997–2001.

6 Montgomery Watson, City of Houston WaterConservation Plan, May 1997.

7 City of Austin Planning, Environmental, andConservation Services Department, 1999National Benchmarking Survey, April 1999.

8 Michelsen, Ari M., et al, Effectiveness of ResidentialWater Conservation Price and Nonprice Programs,AWWA Research Foundation, Denver, Colo.,1998.

9 Vickers, Amy, Handbook of Water Use andConservation, Waterplow Press, 2001.

10 Personal communication with staff members, SanAntonio Water Systems Water ConservationDepartment.

11 Wilcut, Eddie, “A Comparison of WaterConsumption Patterns Between Bill-Allocatedand Nonallocated Multifamily ResidentialEstablishments in San Antonio, Texas, WaterSources Conference, American Water WorksAssociation, 2002.

12 Texas Water Development Board, Institutional,Commercial, & Industrial Water ConservationPrograms: A Guide for Utilities, 1995.

13 Bowman, Jean, “Saving Water in TexasIndustries,” Texas Water Resources, Spring 1995.

14 Hoffman, H. William, Industrial WaterConservation and Reuse in Texas: The Big Picture,Texas Water Development Board, undated.

15 Adapted from David Frashier, Cost ContainmentEngineering presentations on City of HoustonCooling Tower Audits.

16 Compiled from Texas Cooperative Extension,Department of Agricultural Communications,Agnews Service.

17 Daniel, Tamara, “TAES research focuses on centerpivot irrigation management decisions,” TheCross Section, High Plains Underground WaterConservation District No. 1, June 1995.

18 Moseley, Lynn, "District tests use of PET data toimprove irrigation scheduling," The CrossSection, High Plains Underground WaterConservation District No. 1, January 1997 .

19 Texas ET Network, http://www.texaset.tamu.ed20 Fipps, Guy, Potential Water Savings in Irrigated

Agriculture in the Lower Rio Grande Basin ofTexas, Texas Water Resources Institute TR-183,2001.

21 McCarl, Bruce, “Groundwater Marketing:Economic Explorations Involving the EdwardsAquifer,” Proceedings of the 26th Water for TexasConference, 1998.

22 McCarl, Bruce, et al, Evaluation of ‘Dry YearOption’: Water Transfers from Agricultural toUrban Use, Texas Water Resources Institute TR-175, 1997.

23 Keplinger, Keith, et al., 1998 Irrigation SuspensionProgram for the Edwards Aquifer: Evaluation andAlternatives, Texas Water Resources InstituteTR-178, 1998.

References

Prepared by Texas Water Resources Institute,Texas Agriculture Program with funding

from a grant from Environmental Defense.September 2002

efficient water use for texas - texas a&m university

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