Cooperative Extension Service
The University of Georgia College of Agricultural and Environmental Sciences
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Landscape and Turf Irrigation Auditing:

A Mobile Laboratory Approach for Small Communities

D.L. Thomas, Professor and Head, Biological & Agricultural Engineering, Louisiana State University
K.A. Harrison, University of Georgia
M. D. Dukes, University of Florida
R.M. Seymour, University of Georgia
F.N. Reed, Extension Coordinator (ret.), Coffee County, Georgia

Introduction
Procedures
The Douglas, Georgia, Case Study
Summary and Conclusions
References
Appendices

Abstract

A landscape irrigation auditing approach is introduced for small communities where funding is insufficient for a full-time irrigation auditing service component of a water conservation program. The overall objective for the program is to help small communities use their available water resources more efficiently. Landscape irrigation is a major component of water use in many communities, so the implementation of a cost-effective program can be economically viable for communities with limited available funding. The combination of contacts, auditing, and reporting information are designed to achieve the highest potential for success in understanding and implementing water conservation practices in urban landscapes. The approach was tested during a pilot study in Douglas, Georgia. Resulting irrigation system and management alternatives indicated at least a 20 percent reduction in expected irrigation water use if all proposed recommendations are implemented across the community. Recommended incentive approaches are provided to encourage adoption of water conservation alternatives.

Introduction

Landscape irrigation is one of the first water resource uses to be affected by designated drought or water restriction conditions. Odd/even watering (based on the last digit of an address), time periods of allowable water use (such as no outside watering between 10 a.m. and 6 p.m.), and complete outside water use restrictions are logical approaches that communities have used to help manage limited water resources.

In large cities, personnel and funds may be allocated to encourage improved approaches to outside water use. However, many small communities lack the funds to hire personnel to help with their outside water management and must revert to “system-wide bans.” Outside watering bans have a direct and long-term potential impact on some of our most dynamic and thriving industries: landscape plant nurseries, turf/sod operations, and commercial landscape management firms.

In Georgia, statewide outside watering restrictions were implemented in 2000 for the first time in history. Outside watering restrictions have been in place in Florida for several years. These restrictions ban irrigation between 10 a.m. and 4 p.m. and may restrict irrigation to once or twice weekly. The combination of an extended drought, rainfall patterns that do not conform with landscape plant water needs, and sandy soils in many areas that reduce the available water for landscape plants have all contributed to an increasing need for irrigation and better management of water. Georgia and Florida citizens, accustomed to plentiful water and inefficient water use practices, are now aware of the need for improved conservation.

Landscape irrigation is notoriously inefficient because irrigation systems can rarely be designed, installed and maintained at the highest level attainable (unless available funds are not limited and dedicated personnel are responsible for maintaining the irrigation system efficiency). Baum et al. (2002) indicated very low irrigation uniformity (one parameter associated with irrigation system efficiency) values for landscape irrigation systems that were evaluated in Florida.

The overall information provided in this landscape irrigation auditing extension program is not new. In fact, any community interested in improving its landscape irrigation can find good resources to help manage landscape water use if they are willing to take the time and investigate alternatives. A large percentage of homeowners and business owners are unfamiliar with current efficient landscape irrigation technologies. The need to provide a mechanism for direct investigation and information transfer associated with good landscape irrigation practices is vital.

The opportunity to tap the extensive information and technology alternatives for urban landscapes and landscape irrigation, and to package this information in a comprehensive approach that is oriented toward small communities, provides a foundation for a good extension program.

This bulletin presents an approach for improving landscape irrigation efficiency, with alternatives to save water that could be implemented by Cooperative Extension Service personnel or other groups. A pilot study to evaluate the approach was implemented in Douglas, Georgia, a town of about 11,000 residents in the southern part of the state. This bulletin discusses the experience with the pilot study to illustrate the approach and will evaluate how much water savings might result. Computer software for analysis and presentation of audit data was created to facilitate the process. This software is currently available as shareware through the Georgia Cooperative Extension Service. Output from the software is presented in this bulletin.

Procedures

The mobile laboratory approach recommended in this bulletin is designed as a resource to small communities. A mobile laboratory can move into a community for a short period of time, conduct evaluations and make reports, and then move on to another community. Figure 1 illustrates the steps that were ultimately implemented (after some trial and error) to achieve the goals of the auditing program. Since the program is designed to be mobile, a team is expected to spend two to three months working closely with a community (depending on the size of the community).

Figure 1. Illustration of the mobile landscape irrigation audit process.

The ability to have mobile team members be “in a community” indicates the commitment of the sponsoring and funding organizations toward the needs of that community. The mobile laboratory approach (personnel and equipment) should ideally be funded through some type of state appropriation. Specific recommendations that are tailored to a community can improve overall water use and provide incentive programs for the future. In addition, many water purveyors or communities are required to develop and implement a water conservation plan as a part of their permit renewal process.

Developing the Initial Team and Local Liaison

The team and the local liaison are essential to the success of the program. A team needs to include at least two members, with three being ideal. Personnel associated with the auditing team would greatly benefit by being certified through an appropriate irrigation auditor program. Understanding irrigation, ways to trouble-shoot those systems, and appropriate procedures for the actual audit process are included in such programs. The Irrigation Association offers nationwide training for their Certified Landscape Irrigation Auditor (CLIA) program (Irrigation Association, 2002). This program is in conjunction with the Center for Irrigation Technology at California State University (with support from irrigation specialists across the nation). The Irrigation Training and Research Center at California Polytechnic and State University at San Luis Obispo, Cal., provides training programs for auditing landscape irrigation systems as well (ITRC, 2002).

For the southeast region of the United States, a County Extension Agent is a logical choice for the local liaison. This person should have an interest in water conservation. The knowledge of a local county extension agent can include essential contacts and the potential for acceptance of the ideas (local politics). If a local extension agent is not available, someone from the local Soil and Water Conservation District, Natural Resources Conservation Service, or a Resource Conservation and Development Council may be good alternatives. Local water management district water conservation personnel are good contacts in Florida.

Having the mobile audit team in good communication with a local person is essential for “buy-in” (by the local community for the process being used) and potential success of the effort. In addition, the participation of a local agency can create a local contact person who is knowledgeable about landscape irrigation practices and about particular constraints to different approaches. A representative from the water system purveyor may be a good local liaison, but individuals may be reluctant to volunteer without some incentive. If the water system purveyor is the primary choice for a local liaison, participation in the program can be directly tied to positive or negative impacts on a water bill.

Approaching the Water System Purveyor

The organization that is involved in distributing the water to customers is an essential component to the success of a landscape auditing program. Since their direct revenues are usually associated with the amount of water being distributed, the idea of “reducing” that water use is not always met with a positive response and willingness to cooperate. It is important to assure the local water system purveyor that recommendations will include approaches to maintaining their economic viability while reducing overall water use. One long-term incentive is that the water supply infrastructure should last for a longer period of time.

The water system purveyor can provide critical data that is necessary to evaluate the level of outside water use, either by direct results from outside water use meters or by comparing summer-time water use with winter-time values. It is important to remember (when documenting results) that outside water use must be associated with an area of water application to assess the efficiency of those water applications.

The water system purveyor can help determine how many outside water users are present in the community. A sample size of between 5 and 10 percent is considered adequate to evaluate the community water use. This range of sample size has been used extensively as a statistically valid representation of the population (Thomas, 2003).

Enlisting Volunteers for Auditing

Trying to obtain volunteers implies that you must make direct contacts. If the community requires separate meters for outside water use, a letter can be sent to each customer (in combination with the water system purveyor). This letter can contain information about the program, who is doing the activity, what is to be expected of the participants, and what they will receive in return (Appendix A for example). The personal audit information of each water user should be kept confidential. However, they should understand that their information will be used to create a community report. The community report will provide an evaluation of overall outdoor water use issues and solutions that can be applied to the many water users who were not audited.

If a community does not have separate water meters for outside irrigation, the initial contact with potential participants requires a different strategy. A community- or county-based meeting is one recommended approach to initiate the audit program (using standard mass-media contact approaches). This meeting can provide essential information about current water resources, the need for everyone to be involved in conservation (not just the big water users), the audit process, why it will be important to consider water saving alternatives, and who would be involved in the audit program. Partnering with a successful community seminar associated with landscaping is a viable approach to reach volunteers. “Incentives” could be provided by the water system purveyor (or other group) to encourage community meeting attendance.

In this bulletin, “incentives” are positive and negative. We have encouraged positive approaches to participation, but the typical response of some communities may require some negative incentives.

Examples of positive incentives for attending a first meeting could include a small water rebate for a coming month, a coupon to be used with excessive future water bills and rain gauges to help determine water use. The rain gauges could be provided by a local irrigation dealer or landscape contractor in the community. Brochures about landscape water use, landscape planting (Xeriscaping®, etc.), mulching, etc., could also be available at this initial meeting. Potential negative incentives could be an added charge to a water bill if participants with outside irrigation do “not” attend one of the meetings associated with a proposed program.

Questionnaires

Two questionnaires were developed for use with the audit program. The first questionnaire would normally be administered by the local liaison working with the team prior to visiting the individual irrigation system (Appendix B). It determines the working condition of the irrigation system, whether design and layout information could be available at the time of the audit, sets a time/appointment for the actual audit, and records good directions to the site. If the system is not currently in good working order, the audit can be postponed until the system is operational. Interest of water users can be solicited by mail (such as with water bills).

The first questionnaire can be administered by telephone, after a person has indicated that he or she is interested in participating in the audit program. Alternatively, this questionnaire can also be administered in conjunction with the first community contact session. Those who are willing to participate in the audit program can fill out the first questionnaire.

One essential component for administering the first questionnaire is the audit team’s schedule of availability. This schedule is essential to make sure the audit team and the potential participants are both available at the same time. If potential participants do not have scheduling information, the local liaison can follow up with a schedule.

The second questionnaire is used during the actual audit (Appendix B). This questionnaire collects critical information about the system: number of rotating sprinkler heads, nozzles on those heads, zones with mixed irrigation types (typically spray nozzles in combination with rotating sprinklers), zone operating times, any observed maintenance or design problems, and questions to evaluate the “irrigation knowledge” of the water user. By having this questionnaire available during the audit, the person being audited is required to be present. Their presence improves the educational opportunity and enables rapid feedback on obvious problems.

The Audit

After a time is scheduled for the team to meet the water user, the audit team visits the site and evaluates the irrigation system.

The basic steps during that process are illustrated in Figure 2. A logo/shirt is suggested to help identify the audit team. This may be a more logical necessity if the audit team is not continuously escorted by a local liaison. Our initial perception was that many individuals may be reluctant to visit with the audit team until they are confident of the group’s identity (Figure 3). This same logo is potentially available for other universities, states and organizations (replace UGA with another organization name) by contacting the authors.

Figure 2. Basic steps during the on-site irrigation audit.

Figure 3. Shirt logo used for the water auditing team.

During the audit, the system is operated through each zone. One member of the team records the zone information (sprinkler types, number of sprinklers, nozzle sizes, areas covered, full- and part-circle) while another team member observes individual sprinklers for off-site applications, other maintenance problems, and pressure conditions (near and far sprinklers). A pitot-tube pressure gauge can be used to measure pressure conditions if this component appears to be a problem. All information is recorded on data sheets to be sure important information is not neglected. A third team member can question the water user while recording information about the time clock. In many cases, digital pictures can be taken during the actual audit to illustrate problems or good characteristics of the irrigation system. These images can be catalogued by site to help explain particular characteristics to the water user in their individual report.

The person responsible for operating the landscape irrigation system is an essential partner during the audit and should be present (Figure 4). His understanding of the irrigation system operation is necessary to evaluate user information. Many of the expected problems can be observed directly on site during the audit. In most cases, the water user can be provided with information to make initial changes for direct water saving and to improve water use efficiency, prior to receiving a formal report.

Figure 4. Water team member visiting with a homeowner.

Uniformity Analysis

A uniformity analysis can be performed on a selected number of irrigation audit sites (Figure 5). The uniformity of water application is a concern for both rotating sprinklers and spray heads (Baum et al., 2002). A Uniformity Analysis provides a number that indicates the consistency of water application over an area of interest (Smajstrla, 1997). If the water user indicates the presence of “wet” or “dry” spots during irrigation, a uniformity analysis is useful for visual and quantitative analysis of the problems. In most cases, a uniformity analysis may not be necessary (due to the time required). The uniformity analysis includes installing catch cups on a grid interval. More than one irrigation zone may be required to water the particular area, but the purpose is to demonstrate to the water user whether water is being applied evenly across the irrigation area.

Figure 5. Installing catch-cups for a uniformity analysis at one of the audit sites.

The computer program used for the uniformity analysis is available from the University of Georgia (Harrison, 2002). This uniformity analysis program provides the three basic uniformity calculations used most often in analyzing irrigation systems: the Christiansen uniformity coefficient (CU), low quarter DU, and Heerman-Hein equation (Keller and Bleisner, 1990; ASAE, 1994), and is applicable to solid set and center pivot irrigation systems (landscape and agricultural applications). The Heerman-Hein equation is only provided for analysis of uniformity on center pivot irrigation systems and would not be used for landscape system uniformity analysis. The three different uniformity calculations are provided because different groups tend to like or use a particular formula. For our analysis, a low quarter DU of at least 80 percent or a CU of at least 85 percent were considered adequate (Keller and Bliesner, 1990).

The program provides an area for recording com-ments about the irrigation system and a color-coded graphical display of the uniformity results. Those areas where the water application is 20 percent below the average and 20 percent above the average are designated in red and blue, respectively. Areas near the average are displayed in green. The program can be run from the Windows® operating system and is available on a compact disc. An example of the output is provided in Appendix C.

Loss Analysis

The determination of losses for each individual irrigation system component or management alternative can be made on a simple spreadsheet. The spreadsheet approach allows all audit results to be catalogued and summarized from a single site (examples in Appendix D). A spreadsheet can be organized by pages based on individual audit information (identification), rotors, spray heads, and general management conditions. The columns needed are a function of the problems being analyzed. For example, the most common rotor problems may include rotor sizes and nozzles, water pressure, flow rate, the operating schedule (from the time clock), and the area of coverage. These parameters can be recorded in an area associated with current conditions. Standard calculations of application amounts (depth and volume) are adjusted to a per-week basis to allow incorporation of odd/even watering schedules.

The spreadsheet allows different nozzles, times of application and spacings to be evaluated for potential water savings in an area associated with “changes.” Maintaining individual worksheets for each individual component allows determination of community or “total audit” effects of particular water saving alternatives. It is important that “current/actual” conditions be fixed in the spreadsheet to reduce the possibility of making recommended changes that are not reflected in the efficiency or water saving results.

One problem with this spreadsheet approach is for those irrigation systems where sprinklers have been replaced over time with different sprinkler heads. In many cases, systems that have been in for many years will require replacement of sprinkler heads. Invariably, the exact same sprinkler head is not available locally. In most cases, the sprinklers that are present over most of the irrigated area are represented in the data sheet. If a system has a significant number of sprinkler heads of more than one type, separate lines can be added on the spreadsheet.

All loss calculations in our analysis are based on “expected” water applications at the high water use period (usually mid-summer but can be spring -- the period with less rainfall). Peak demand periods tend to stress a water system and available water supplies. Additional recommendations need to be provided for seasonal adjustments to the overall water use, but these generalized recommendations can be included in both the individual and community reports (not in the spreadsheet).

Reports

Prepare an individual report for each audit site. This report contains general information that relates to most irrigation systems as well as specific information on the system being audited. For example, some water saving technologies can be illustrated (such as rainfall cut-off switches). Particular off-site application or maintenance problems can also be identified. Specific recommendations for the irrigation system (nozzle changes, time of application within a zone, etc.) are described for calculating direct water savings. These potential water savings are reported to the water user as a way to encourage changes in the system (see Appendix E for an example of an individual report).

>Recommendations are indicated for changes that should be implemented when a major repair is warranted. Zones with too many sprinklers, mixed spray heads and rotors, and time clock problems would require significant (and potentially costly) modifications. Making these changes when the system already needs repairs is a logical alternative.

A community report is necessary to illustrate the overall water savings that could be expected by instituting water saving alternatives (see Appendix F). Most results can be reported in percentages with direct reference to potential gallons saved during a period of time. The opportunity to save water should include alternatives to maintain income for the water purveyor. Recommendations for nozzles to be available for retrofitting rotating sprinklers, rain gauges to help keep track of current conditions, and other water saving practices can be provided in the community report as potential incentives to achieving actual reductions in water use for the community.

Acknowledging Participation

It is essential to acknowledge the support provided by the community and the sacrifice made by the participants in allowing the team to do an audit. Award certificates for appropriate community leaders (City Manager and Water System Coordinator) and each of the individual operators and homeowners. Maintaining the contact and good will associated with the audit process is essential to the follow-up necessary to help a community implement the recommendations.

The Douglas, Georgia Case Study

Background

A pilot study of the mobile landscape irrigation auditing program was conducted in Douglas, Georgia (Coffee County). Douglas is located at coordinates 31º 31' N and 82º 50' W in south Georgia; it is between Albany and Savannah. Ground water is the primary source for the drinking and landscape water supply. Water is supplied from the Upper Floridan aquifer with pumps located about 35 m below the ground surface. Douglas had about 186 total outside water use meters (in 2002). All households do not have outside water meters. This metering approach may not be typical for many small communities. Total city water use (excluding industry) is about 7,570 m³ per day (2 million gallons per day, mgd), which implies about 0.69 m³ (182 gallons) are used per person per day. This amount may not seem extravagant. However, estimates of average per capita consumption throughout the United States range from 0.38 m³ (100 gallons) per day (Wade, 1998) to 0.58 m³ (153 gallons) per day (Gleick, 1996). Most organizations recommend about 0.38 m³ (100 gallons) per day are “necessary” to maintain a good quality of life.

The city of Douglas uses a block rate structure for their water users (Table 1). The current block rate structure does not specifically encourage water savings since the cost per volume decreases with increased usage. Most water users with operating irrigation systems would be in blocks 3, 4 or 5, depending on the area being irrigated. For example, a 1,350 m² (⅓ acre or 14,500 ft²) irrigation area that is irrigated 38 mm (1.5 inches) per week would be expected to use about 200 m³ (53,500 gallons) in a month during the summer. Water use would include block 5, with a resulting $59.00 water bill for outside water use for that month. The cost to the user, revenue to the water system purveyor, and relative impact of increased costs versus water saved must all be determined for “proposed” water reductions to become “actual” water reductions.

Procedures

Audits were performed on 14 different systems in the community (>7 percent sample). The selection was based entirely on those who requested an audit after receiving a notice in the mail. Half of the audits were on commercial or municipal sites, the rest were residential customers. Most of the irrigation systems evaluated were in the form of standard landscape irrigation devices (rotors, spray heads and drip). Only one audit included a large traveling gun (hose tow) system, which was used for sport turf irrigation.

The Douglas community was operating under an odd/even watering restriction (based on address) when the audit was performed. Water users were allowed to irrigate every other day. A 6-hour time period (4 p.m. to 10 p.m.) was designated across the state of Georgia to eliminate/reduce home water use every day. Many communities in Georgia and surrounding states have instituted additional constraints. Most time clocks were set to allow irrigation during early morning hours (within the water use restrictions), thus reducing expected losses due to evaporation. Unfortunately, early morning hours (12 a.m. to 5 a.m.) tend to encourage other potential losses. Offsite applications, maintenance problems (broken sprinklers), and small leaks (if the evidence of the leak is not substantial) are not easily observed during early morning operation periods.

The water saving opportunities listed below are based on “potential” water savings during peak summer use periods with no supplemental rainfall. Obviously, if rainfall occurs or the period is associated with the fall, winter or spring seasons, the water use required would be less, and the potential water savings would be less for the system and management changes.

Results

Water Saving Opportunities

The largest problem observed within the audits was selection of nozzles in rotating sprinklers. Regardless of whether sprinklers were old or new, nozzles were not sized according to the area of coverage by the rotating sprinklers. For sprinklers that were operating over part circles, the same nozzles were typically used as those in the full circle sprinklers. This is not a problem if all full circle sprinklers are on the same zone, all part circle sprinklers are on a different zone, and the operating times are adjusted accordingly. Results from the Douglas community tests indicate that nearly 24 percent of the water used on rotating sprinklers could be saved by using the proper nozzles (based on those systems tested, with no other changes in operating schedules). This percentage translates into nearly 151 m³ (40,000 gallons) of water per week (during peak summer water use periods) that could be saved on the 14 systems tested, by using proper nozzles. For the individual systems tested, the water savings due to nozzle changes ranged from 0 to 45 percent.

Operating time was another concern illustrated from the irrigation audit results. In most cases, spray heads tend to put out three to five times the water application rate on a given area as compared to drip or rotating sprinklers. If the time is not adjusted for the different spay head rates, those areas will receive a much higher application of water. For those systems with spray head problems (60 percent of those systems with spray heads), about 19 percent of the water used through spray heads could be saved by adjusting the time to conform to a “recommended” amount that was consistent with the rotating sprinkler amounts. Turf needs about 32 mm (1.25 in. via irrigation or rainfall) per week during peak water demand periods (Tyson and Harrison, 1995; Wade et al., 2000) in south Georgia. This water savings percentage translated into more than 18.9 m³ (5,000 gallons) of water saved per week during peak summer use periods for the systems tested.

On one system, the operating time per irrigation was 180 minutes (with rotors). If this system is operated on an odd/even irrigation schedule, the application amount per week is nearly 50 mm (2.0 inches). Reducing the zone time to 120 minutes per irrigation saves about 18 m³ (4,700 gallons) per week on this system alone.

Off-site applications were a real problem in some areas. Spray heads and rotating sprinklers applied water on roads, sidewalks, driveways and parking lots; hitting nearby bushes and trees (significantly affecting the pattern); and even putting water into a swimming pool. Recommendations to save water were based on converting some full circle rotating sprinklers to part circle. Water savings based on off-site applications are “real” based on any application scenario because this water is not being used for any beneficial plant response. Off-site applications represented a relatively small percentage of the overall water use, but they are the primary concern when addressing public perceptions about irrigation system efficiency.

For one system tested, changing a full circle sprinkler to a 270 degree coverage would save about 0.8 m³ (210 gallons) per week. For another system, changing a full circle sprinkler to a half circle sprinkler amounted to about 0.4 m³ (100 gallons) per week in water savings. This analysis was based on the current operating time set to provide 12.7 mm (0.5 inches) of water per week. All of the above savings were based on the current irrigation schedule (time of application in a zone) and the particular nozzles being used.

Changes were also recommended based on the season. In the majority of the audits, no direct effort was made by the water user to reduce water applications during the fall, winter or spring. In some cases timing was modified if areas were too wet. Rarely were the seasonal adjust features (water budgeting) used on time clocks. The potential for educational efforts to help water users more effectively use their time clocks was evident in almost all audit situations.

All reports contained a recommendation for the installation of a rainfall shutoff or soil moisture sensor. Some sensors can turn the system off when it starts raining. Other sensors monitor the soil moisture and will prevent the system from operating if the soil water conditions are adequate. In Florida, rainfall shutoff sensors are required. This is not the case in many other states, including Georgia.

Efficiency Improvements, but More Water Needed

In some cases, water application recommendations were provided to help meet potential plant water needs. Some irrigation systems were not providing sufficient water to meet plant water requirements at peak summer conditions. Recommendations that increase the amount of water applied to a particular area would lead to increased efficiency but also increased water use. Obviously, if the water user is satisfied with the condition of the turf and landscape plants, these recommendations should not be implemented (indicated in their report). Schools are one typical irrigation system location that may not need as much water during the summer (if schools are not in session). Maintenance during the summer should be low and appearance may not be as important (low application amounts may be acceptable). Unfortunately, the climate in the southern United States encourages the encroachment of drought-tolerant weeds if sufficient water is not available to the turf.

Application amounts for rotors seemed to be low for a large percentage of the systems evaluated (50 percent of those tested). These systems were putting out less than 15 mm (0.6 in.) over a week (based on applications “every other day”). Some of these sites may have low water application rates because of anticipation of rainfall. Unfortunately, when it does not rain for extended periods, the water supply is insufficient for most turf types. These application amounts may need to be adjusted based on the stresses observed on turf and landscape plants. The amount applied can easily be corrected by adjusting operating time(s) per zone. However, this would result in increased water use for those particular systems.

Alternative Water Rate Structures

The largest concern by the water purveyor was the potential loss in revenue associated with water use reductions. By modifying the water rate structure, the loss in revenue can be offset to address those persons making the changes. We estimated that most irrigators would be in blocks 3, 4 and 5 based on their schedule and irrigated area.

What if the block water rate structure described in Table 1 were “readjusted” to penalize those who use more water (inclining water rate structure)? For exam-ple, the water rate for blocks 3, 4 and 5 could be increased ($/1,000 gal.) to encourage outside water users to use less water (Table 2). Income to the water purveyor would not be reduced, since those wishing to use more water would pay an increased rate. The example presented previously indicated a cost of $59.00 per month to use about 200 m³ (53,500 gallons). If the water user reduced outside water use by 20 percent (to about 160 m³ or 42,800 gallons), the water bill would be about $58.86 (Table 1). If the user did not choose to reduce water use, the water bill would be about $75.25.

Positive incentives, such as reduced water rate structures by the implementation of water saving alternatives, could also be used to encourage reduced water use. However, the opportunity to maintain a water bill near the previous level by saving water was considered a very good incentive.

Summary and Conclusions

A new mobile landscape irrigation auditing program was developed for small communities in the southeastern United States, and was tested in a pilot study in Douglas, Georgia. Fourteen individual systems were audited (>7 percent of outside water meters). Fifty percent of the audit sites were municipal or commercial sites and 50 percent were residential. For the audited systems, at least 950 m³ (250,000 gallons) per week were estimated to be used if all systems were operating on an “every other day” irrigation schedule during peak water use periods. If all recommendations for water savings were implemented on these systems, about 190 m³ (50,000 gallons) per week (20 percent) would be saved. All potential water savings were based on a combination of system and management alternatives toward applying less water if they were currently exceeding recommended amounts (per week).

Some audited sites were applying less water than is recommended for turf and landscape plants (during the hot part of the summer). Irrigation efficiencies and possibly health of turf and landscape plants could improve by applying more water.

In practically all irrigation audit situations no seasonal adjustments were being made to reduce water applications during the fall, winter, and spring seasons of the year. The need for improved education on irrigation and operating system alternatives was obvious.

The audit program represents a real, potentially viable method of improving water use for small communities. The potential to use water more efficiently and save water under drought conditions is necessary to the future of the landscape and turf industries, and the quality of life and quality landscapes expect.

The proposed procedures provide limited alternatives for potential water savings. Other approaches, such as deficit irrigation (putting out less water than is needed by plants), encouraging the use of low water use landscape plants (such as Xeriscaping®), rebates on water bills after implementing water saving approaches, etc., can encourage even greater water savings and higher levels of participation.

References

ASAE Standard. 1994. ASAE Standard No. S436. Test procedure for determining the uniformity of water distribution of center pivot, corner pivot, and moving lateral irrigation machines equipped with spray or sprinkler nozzles. ASAE, St. Joseph, MI.

Baum, M.C., M.D. Dukes, and G.L. Miller. 2002. Residential irrigation uniformity and efficiency in Florida. ASAE Paper no. 02-2246. ASAE, St. Joseph, MI. 25 pp.

Harrison, K.A. 2002. Irrigation system analysis and computation (ISAAC). University of Georgia. Cooperative Extension Service, Athens, Ga. Public Software.

Irrigation Association. 2002. The Certified Landscape Irrigation Auditor Program. http://www.irrigation. org/certification.htm

ITRC. 2002. Irrigation training and research center. http://www.itrc.org

Gleick, P. 1996. Basic water requirements for human activities: Meeting basic needs. International Water 21(2):83-92.

Keller, J., and R.D. Bliesner. 1990. Sprinkle and Trickle Irrigation. Van Nostrand Reinhold Publishers.

Smajstrla, A.G., F.S. Zazueta, and D.Z. Haman. 1997. Lawn sprinkler selection and layout for uniform water application. University of Florida, Cooperative Extension Service Bulletin no. 320. see: http://edis.ifas.ufl.edu/AE084

Thomas, D.L., K.A. Harrison, R. Reed, R. Bennett, V. Perez. 2002. Landscape and turf irrigation auditing: a mobile laboratory approach for small communities. ASAE Technical Paper No. 02-2247. ASAE, St. Joseph, MI. 30 pp.

Thomas, D.L., Editor. 2003. Development of a monitoring/modeling system for agricultural water used determination. A project report for completion of the Ag. Water Pumping Program. Funded by the Georgia Geologic Survey Branch, Environmental Protection Division, Department of Natural Resources. 43 pp.

Tyson, A.W., and K.A. Harrison. 1995. Irrigation for lawns and gardens. University of Georgia, Cooperative Extension Service Bulletin. http://pubs.caes.uga.edu/caespubs/pubcd/b894-w.html

Wade, G.L. 1998. Be a water wise guy. You can have twice the landscape for half the water. In Drought in Georgia. www.georgiadrought.org. Departmental Publication H-99-046. Cooperative Extension Service, University of Georgia.

Wade, G.L., J.T. Midcap, K.D. Coder, A.W. Tyson, and N. Weatherly, Jr. 2000. Xeriscape™: A guide to developing a water-wise landscape. University of Georgia, Cooperative Extension Service Bulletin. http://pubs.caes.uga.edu/caespubs/pubcd/b1073.htm

APPENDIX A. Example letter to potential participants

Irrigation Water Audits in Landscapes

You are receiving this special notice because you have been identified as an outside water user (since you have a separate water meter for irrigation). Everyone has been impacted by the ongoing drought. The Georgia Department of Natural Resources has imposed statewide watering guidelines to help with the drought conditions. Consequently water use outside the home is becoming a “ critical issue” in water conservation talks and is being blamed for many of the problems associated with shortages and potential wasting of water.

The Biological and Agricultural Engineering Department of the University of Georgia (UGA) would like to implement a pilot program which is aimed toward you, the landscape/outside water user. Basically, we are interested in saving water through more efficient irrigation practices, rather than “cutting off your water supply.” This pilot program will include performing what is called “water audits” on a random sample of landscape irrigation systems in your community. These audits are designed to more adequately explain the water conditions that currently exist in the landscape irrigation area. This data will be used to develop a program on a statewide basis. We have selected the Douglas water system as a pilot community.

What will the audit require of me? The audit is usually a “two step” visit. The first step is to meet with you and determine as much information as possible about the type of irrigation you have and how you manage the irrigation. This will involve mostly answering questions about the irrigation system and will require about 30-45 minutes of your time. Once it has been determined that the irrigation system can be tested, the actual field audit will be conducted. The actual field audit will require that the irrigation system be operated for about 30 minutes and UGA personnel will collect the necessary field data. A report will be developed that includes information like recommended operating schedules, uniformity of application, and maintenance. This report will be discussed with you on an individual basis, and a copy will be provided to you for planning purposes (in case there are suggested changes for your system that you may wish to implement). A complete audit may require up to a half day.

The good news is that there is no charge for this audit! All the information gathered will be held as confidential and will not be associated with an individual name. We do plan to provide a “community report” to Douglas which describes the most consistent practices/ideas for saving water. Since this is a pilot program, the participation will be limited to the first XX-XX systems who sign up. At this time, the pilot program is scheduled to get started around the first week in September. If you would be willing to volunteer your landscape irrigation system for a water audit, please fill out and return the lower portion of this page. You will be contacted by Rick Reed to schedule your audit. If you have questions, please feel free to call: XXXX, Coffee County Extension Service at XXX-XXXX or XXXXXXX, City of Douglas at XXX-XXXX.

APPENDIX B. Questions to ask prior to and during the initial landscape irrigation visit

Questions to ask during the phone conversation when setting up appointments:

Identify who you are, and what you are calling about.

Intro? Something like: Landscape irrigation is one of the first uses that is affected when water supplies are limited, or restrictions are put in place. If we can improve the efficiency of water use in landscape irrigation, we can potentially have more water available for current and future uses.

1.   Make sure of name, address, telephone number:

2.   It would help us greatly in planning your direct audit if we had your past history of water use. Realizing that any recommendations are designed to “improve” water use over what you have done in the past, do you have any problem with team members from the University of Georgia seeing your water bill?

3.   How much area (square feet) are you irrigating? Or do you know the dimensions of your lot? X ft by Y ft _________________________________________________ (circle above, put down units, sq. ft, acres, etc.)

4.   What kind of irrigation system do you have? (Buried/permanent, portable, rotating sprinklers, spray heads, drip/micro) — Circle all that apply — If the system is PORTABLE, ask the next two questions:

      4b. What are the weekly water requirements for your landscape plants and lawn?

            landscape plants _____________(inches/week)         lawn _____________ (inches/week)

      4c. What is your operating schedule?

5.   Is your irrigation system currently in working order?

If answer is “No,” what would it take to make it “operational”? Note: system must be operational before we can schedule a site visit.

 If answer is “Don’t know,” does someone else (such as a landscape contractor) operate/manage/maintain your system for you?

6. Will you participate in the audit program?

7. Is there (or do you have) a schematic/plan for the irrigation system?

If “yes,” can you have it available at the time of the site visit?

8.   Is there a specific time (2 to 3 hours) between Date 1 and Date 2 (preferably during the week) that a team from the University of Georgia could visit with you about your landscape irrigation system?

Date and time of the audit:

9.   During the visit, team members will ask additional questions about your irrigation system and may do a direct measurement of water application uniformity. A confidential report will be provided to you about your system. The information from your system will be used with other audits for a general report to the city of Douglas. The main interest is to help you and the community use water more efficiently and hopefully save water both now and into the future.

If so, what are driving (or special) instructions to get to the house/site? (use noted landmarks)

10. If a landscape company is used (yes to question 5b) and the homeowner is interested in participating in the audit program (yes to question 6), the homeowner is offered the opportunity to invite the landscape contractor to be present during the audit. Will landscape company be invited to be present?

11. Would you be interested in an audit of “in home” water use?

12. If something comes up, and the schedule needs to be changed, please call my office number.

Questions to be asked during the landscape irrigation audit:

Installation and Maintenance:

1.   If there was a plan (question #7 from above), can we get it now?

2.   What made you decide to install the irrigation system?

Wanted my yard to be pretty all year round
Didn’t want to mess with moving sprinklers around
Didn’t have time to irrigate any other way
________________________________________________________________

3.   What outside sources did you use for information to make your decision?

________________________________________________________________

4.   Is there anything (other than price) that you considered when installing the system?

Examples: product reliability, maintenance, management time required, etc.

5.   Did you hire someone to install the irrigation or did you do it yourself?

6.   What maintenance has been performed and why was it done?

Example: Head replacement, added sprinklers, new time clock, etc.

7.   What improvements would you like to see in your system? OR If you had it to do over again what would you change?

8.   How old is the system? __________________ years

9.   Are you aware of any problems with the system (like water in the street)?

Scheduling:

10. What are the weekly water requirements for your landscape plants and lawn?

11. What is your operating schedule? Note: Compare verbal answer with actual time clock settings. Will need to go “zone by zone” with owner if system is manually operated.

12. Based on information from the telephone interview, you “are”/“are not” using a landscape contractor/lawn maintenance company. Check all the following that apply if they “are.”

Field Evaluation by UGA (do not ask homeowner):

13. What types of irrigation are used?

Working knowledge of irrigation system?

14. If you had to prioritize water for different uses, how would you rank the following (personally): Use 1-5, where 1 is the most important to you. (Given to the homeowner on a card?)

APPENDIX C. Example output from the uniformity analysis program.