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© 2009 Plant Management Network. Golf Course Environmental Profile Measures Water Use, Source, Cost, Quality, and Management and Conservation Strategies Clark S. Throssell, Greg T. Lyman, Mark E. Johnson, and Greg A. Stacey, Golf Course Superintendents Association of America, 1421 Research Park Drive, Lawrence, KS 66049; and Clark D. Brown, National Golf Foundation, 1150 S. US Highway 1, Suite 401, Jupiter, FL 33477 Corresponding author: Clark Throssell. cthrossell@gcsaa.org Throssell, C. S., Lyman, G. T., Johnson, M. E., Stacey, G. A., and Brown, C. D. 2009. Golf course environmental profile measures water use, source, cost, quality, and management and conservation strategies. Online. Applied Turfgrass Science doi:10.1094/ATS-2009-0129-01-RS. Abstract The golf industry does not have comprehensive national data on property features, management practices, and inputs associated with golf courses. As part of the effort to develop a national golf course environmental profile, The Environmental Institute for Golf sent a survey to superintendents at 16,797 golf facilities in the United States to determine their number of irrigated turfgrass acres, water use, water cost, water sources, recycled water use, water quality, irrigation system characteristics, and water management and conservation strategies. Of these surveys, 15% were returned. Golf course data were stratified by agronomic region, course type, and number of holes. The analysis indicated proportional representation of all types of golf facilities in the results. Golf courses comprise an estimated 1,198,381 acres of irrigated turfgrass in the United States, and their total annual water use averaged over 2003, 2004, and 2005 is estimated at 2,312,701 acre-feet. Water cost and water source vary by agronomic region. Recycled water is one of the water sources for 12% of golf facilities. Nearly all 18-hole golf facilities use one or more techniques for irrigation scheduling, and they use multiple management practices such as hand-watering to conserve water. These data provide an accurate portrayal of golf course water use that establishes a baseline for comparison with data from future surveys to monitor industry change, and the data can serve as a guide for industry agronomic and environmental initiatives. Introduction Golf course superintendents, golf industry leaders, golf association leaders, environmental advocates, university turfgrass scientists, and state and local environmental regulators participated in meetings held in 2003 and hosted by The Environmental Institute for Golf (Lawrence, KS) to identify and prioritize research, education, and outreach needs to help The Institute fulfill its mission of strengthening the compatibility of the game of golf with the natural environment. As an outcome of these meetings, it was learned that the golf industry did not have comprehensive data on the property features, management practices and inputs associated with golf courses and golf course maintenance. Another outcome was that, although many individual golf courses had made changes to make golf courses more compatible with the environment, there was no systematic process in place to document changes that the golf industry has made to protect and enhance the environment. In recent years, state surveys of golf course maintenance practices have provided useful information for the states involved. Unfortunately, the questions asked on each state survey were not uniform and the responses covered different time periods so that combining data from the different state surveys would not produce a valid national profile of golf courses and their maintenance practices. The Golf Course Superintendents Association of America (GCSAA)(Lawrence, KS) initiated a project in 2006 to collect data nationwide on the property features, management practices, and inputs associated with golf courses and golf course maintenance. A series of surveys conducted over a period of several years will be used to collect the needed information. Once the first phase of data collection is complete, the surveys will be repeated. This will provide data to determine change in golf courses and golf course maintenance practices over time. The first survey was conducted in 2006 and determined total acreage of a golf course, land-use characteristics, acres and grass species of each component of the golf course, acreage dedicated to natural resources, and environmental stewardship practices. The results indicated that an average 18-hole golf course is 150 acres, of which 100 acres (67%) is maintained turf. Cool-season grasses are grown on 66% and warm-season grasses are grown on 34% of all maintained turf acreage on golf courses. The remaining acreage is comprised of non-turfgrass landscapes (16%), water bodies (7%), buildings (4%), bunkers (3%), and parking lots (3%). Approximately 44% of golf courses have increased the non-turfgrass landscape areas by nearly 10 acres over the last 10 years. Over the last 10 years, an average of five environmental improvements have been made on 18-hole golf courses, while golf courses that have participated in voluntary environmental stewardship programs have made an average of seven improvements (9). The objectives of this survey were to determine: number of irrigated turf acres, water use, water cost, water sources, recycled water use, water quality, irrigation system characteristics, and water management and conservation strategies. Question Development Input on critical information needed to develop an accurate environmental profile of golf courses was collected from golf course superintendents, golf industry leaders, golf association leaders, environmental advocates, university turfgrass scientists, and state and national environmental regulators. GCSAA staff used this information to draft survey questions, which were reviewed by a group that was made up primarily of golf course superintendents but also included golf association leaders and environmental advocates who had not previously seen the survey. Feedback from this group was used to revise the survey questions. The revised survey was sent to the National Golf Foundation (NGF) (Jupiter, FL) for refinement and formatting for on-line and paper versions. Ten superintendents who had not previously seen the survey completed a test survey, and their suggestions for improvements were incorporated into the final version. The NGF adheres to The Code of Marketing Research Standards developed by the Marketing Research Association (10). Survey Procedures GCSAA and NGF databases on golf facilities, including name of facility, mailing address, phone number, fax number, and superintendent’s name and contact information, are updated on a continual basis. An attempt was made to contact and recruit superintendents at 16,797 golf facilities in the United States to complete the water use and conservation survey. An e-mail invitation to participate in the survey was sent to approximately 7,014 superintendents with a known e-mail address. Superintendents without an e-mail address were sent an invitation postcard by mail. The invitation explained that individual responses would be kept confidential and that data would be analyzed in aggregate by agronomic region. Surveys were sent in October 2006 by e-mail, fax, or mail. In addition, reminders to complete and submit the survey were sent by e-mail and mail. Surveys were accepted until late November 2006. The survey instrument is in Appendix A. Golf courses were stratified by agronomic region, course type (daily fee, municipal, or private), and number of holes (9, 18, or 27+) to ensure that all types of golf courses in all regions of the country were adequately represented in the final data set. A total of 2,548 completed surveys were returned from 16,797 golf facilities, yielding a 15% return rate. The data collected were not independently validated due to time and resource limitations. All completed surveys were screened to determine whether the response to any single question was reasonable in the context of the rest of the responses on that survey. Any response to a question that was judged to be an outlier was omitted from the analysis. A conservative approach to identifying outliers was used for this analysis. Values from respondents that were more than three times the standard deviation from the mean were omitted when they were considered human error. An example is an 18-hole golf facility that reported total annual water use well outside a comparable range of 14 to 150 million gallons. The name of the golf course on the returned survey was compared to the database of all golf courses in the United States to make sure the survey came from an existing golf course and that no duplicates for a single course were received. Analysis of the completed surveys indicated a representative sample of the golf facilities in the United States was received (Table 1). The number of golf facilities under region, type, and number of holes does not add up to the same total because information for some golf facilities was incomplete. Agronomic regions and the location of golf facilities responding to the survey are shown in Figure 1. Agronomic regions were delineated by grouping geographic areas with similar agronomic and climatic characteristics using previously published regions as a guide (2,12). Boundaries were drawn using county borders. Table 1. Number of golf facilities, percent of total number of golf facilities, completed surveys received, percent of the total completed surveys received, response rate within the category, and margin of error for agronomic region, course type, and number of holes.
w The total number of completed surveys was 2,548. x The total number of golf facilities was 16,797. y Response rate is the percentage of the total number of completed surveys received for each region, course type and course classification (9, 18, or 27+ holes). z At 90% confidence interval.
Data were analyzed using Quantum crosstabs and SPSS analytics software (SPSS 15.0 for Windows, SPSS Inc., Chicago, IL) to run descriptive statistics and t-tests were performed to explore relationships between categorical variables such as agronomic region, course type, and number of holes. Confidence intervals of 90% were used for mean separation. Where 18-hole equivalent data are presented, data within a region were averaged over facility type and budget. The number of 18-hole equivalents in the USA is 14,969 and was determined by taking the total number of golf holes and dividing by 18 (11). All budgets and expenditures are reported in 2005 US dollars. Irrigated Turf Acres There are an estimated 1,198,381 acres of irrigated turfgrass, which is approximately 80% of the 1,504,210 acres of maintained turfgrass, on United States golf courses (9). Nearly 100% of greens, tees, and fairways are irrigated, with the non-irrigated turfgrass acres located in the rough and the driving range/practice areas. Approximately 36% of the rough (276,749 of a total of 777,051 acres) and approximately 26% of driving range/practice areas (29,638 of 112,766 acres) are not irrigated (8). Most of the non-irrigated rough and driving range/practice areas are in the Northeast (65% and 55%, respectively), North Central (61% and 45%, respectively), and Transition agronomic regions (43% and 28%, respectively) (9). As expected, the number of acres of irrigated turfgrass at a golf course increases as the number of holes increases (Table 2). The average number of acres of irrigated turfgrass per golf hole is 2.9 for a 9-hole course, 4.5 for an 18-hole course, and 4.7 for a 27-hole golf course. Private golf courses have significantly more irrigated turfgrass acres than public golf courses, and the number of irrigated turfgrass acres increases as the maintenance budget increases (Table 2). An average 18-hole golf course has 80.7 acres of irrigated turfgrass, of which approximately 80% are dedicated to fairways (30.7 acres) and rough (33.8 acres) (Table 3). In the Southwest agronomic region, an average 18-hole golf course has 115 acres of irrigated turfgrass (significantly more than any other agronomic region), and in the Northeast region, an average 18-hole course has 54 acres of irrigated turfgrass (significantly less than any other agronomic region) (Table 4). While the data on number of irrigated acres on an average 18-hole golf course might seem counterintuitive, turfgrass will not survive without irrigation in the Southwest agronomic region. Therefore, all the turfgrass must be irrigated. In contrast, in the Northeast agronomic region, non-irrigated turfgrass will survive without irrigation, and during much of the growing season it will flourish because of adequate rainfall. Table 2. Irrigated turfgrass acres, irrigation water expenditure, water expenditure per irrigated turfgrass acre, and percentage of golf facilities using recycled water in the USA by golf facility characteristic.
x Within a column and golf facility characteristic, values followed by the same letter are not significantly different from one another. Letters denote significance at the 90% confidence level. Table 3. Number of irrigated acres and percentage of total irrigated
Table 4. Irrigated turfgrass acres, water use, and water use per irrigated turfgrass acre on an average 18-hole golf facility by agronomic region.
x Agronomic regions: NE = Northeast; NC = North Central; Trans = Transition; SE = Southeast; SW = Southwest; UW/Mtn = Upper West/Mountain; Pac = Pacific. y Within a row, values followed by the same letter are not significantly different from one another. Letters denote significance at the 90% confidence level. For 18-hole golf courses over the past five years, 66% have maintained the same amount of irrigated turfgrass, 25% have increased irrigated turfgrass by an average of 13.0 acres, and 9% have decreased irrigated turfgrass acres by an average of 12.3 acres (Table 5). It is believed one of the reasons 25% of 18-hole golf courses have increased the number of irrigated turfgrass acres is to meet golfers’ demand for improved playing conditions. The average decrease in irrigated turfgrass on the average 18-hole golf course ranged from a high of 17.9 acres in the Southwest to a low of 8.2 acres in the Upper West/Mountain agronomic region (Table 5). Table 5. Changes in irrigated turfgrass acres on United States golf facilities since 2001.
x Agronomic regions: NE = Northeast; NC = North Central; Trans = Transition; SE = Southeast; SW = Southwest; UW/Mtn = Upper West/Mountain; Pac = Pacific. y Within a row, values followed by the same letter are not significantly different from one another. Letters denote significance at the 90% confidence level. Water Use The agronomic regions used in this survey cover large geographic areas. On a macro-scale, agronomic conditions within each region are similar. On a micro-scale, agronomic and market conditions can vary substantially from golf course to golf course within these regions. Climatic conditions, including amount of precipitation and evapotranspiration rate, soil type, grass species, length of growing season, management practices, and customer (golfer) expectations will significantly influence water use on golf courses within an agronomic region. Total annual water use for all golf facilities nationwide averaged over 2003, 2004, and 2005 is estimated at 2,312,701 acre-feet (Table 6). Annual water use averaged over 2003, 2004, and 2005 for all golf facilities is greatest in the Southeast agronomic region at 801,105 acre-feet followed by the Southwest agronomic region at 553,442 acre-feet. Golf facilities in the Southwest agronomic region use more water per irrigated turf acre, but the Southeast agronomic region has nearly three times more golf facilities (3,518) than the Southwest agronomic region (1,272). At 94,115 acre-feet, annual water use was lowest in the Pacific agronomic region, partly because that region has only 682 golf facilities. Average annual water use on 18-hole golf facilities was significantly higher in the Southwest than in other agronomic regions at 459.0 acre-feet, followed by the Upper West/Mountain agronomic region at 300.4 acre-feet. The lowest average annual water use on golf courses was significantly lower in the Northeast than in all other agronomic regions at 42.4 acre-feet (Table 6). A year-round growing season, high rates of evapotranspiration, and a greater number of irrigated turf acres all contribute to higher annual average water use in the Southwest region. Water use per irrigated turf acre is lowest in the Northeast and highest in the Southwest regions (Table 4). The period of greatest water use at the average US 18-hole golf facility corresponds to the period of greatest evaporative demand and turfgrass water use and occurs during July and August when 41% of the yearly total water is applied. In May-June, the next-highest water use (26%) occurs. September-October follows with 18% (Table 7). Table 7. Water use by two-month periods for an average 18-hole golf facility in the USA and within each agronomic region.
x Agronomic regions: NE = Northeast; NC = North Central; Trans = Transition; SE = Southeast; SW = Southwest; UW/Mtn = Upper West/Mountain; Pac = Pacific. y Within a row, values followed by the same letter are not significantly different from one another. Letters denote significance at the 90% confidence level. Monthly water-use patterns varied by agronomic region, with water use concentrated in May to October in the Northeast, North Central, Transition, Upper West/Mountain, and Pacific agronomic regions. In the Southeast and Southwest regions, water use is spread more evenly throughout the year because of year-round evaporative demand, turf growth, and golf course use (Table 7). Water Cost Total expenditure for water increases as the number of holes at the golf facility increases because of the associated increase in number of irrigated turf acres (Table 2). Private golf courses spend significantly more for water than public golf courses. Golf courses with an annual maintenance budget of $1,000,000 or greater spend significantly more for water than golf courses with an annual maintenance budget of $500,000 to $999,999, which spend significantly more for water than golf courses with an annual maintenance budget of $499,999 or less (Table 2). There are a disproportionately higher number of golf courses in the Southwest agronomic region with an annual maintenance budget of $1,000,000 or greater compared to other regions. The combination of a year round growing and golfing season, higher water use, higher expenditure for water, and the demand for premium playing conditions may lead to higher maintenance budgets on golf courses in the Southwest agronomic region. Calculated average water expenditure per irrigated turf acre is $204 for 9-hole golf courses, and $243 and $242 for 18- and 27-hole golf courses, respectively. Private golf courses spend more for water per irrigated turf acre than public golf courses, and golf courses with higher maintenance budgets spend more for water per irrigated turf acre than golf courses with lower maintenance budgets (Table 2). Average annual expenditures for irrigation water are highest in the Southwest agronomic region at $107,800 and lowest in the North Central ($4,700), Northeast ($6,300), and Transition agronomic regions ($6,900) (Table 8). The water expenditure per irrigated turf acre is highest in the Southwest agronomic region ($937) and lowest in the North Central agronomic region ($71) (Table 8). Table 8. Irrigation water expenditure and water expenditure per irrigated turfgrass acre for an average golf facility (including facilities that do not pay for water) and the percentage of 18-hole golf facilities that do not pay for water by agronomic region.
x Agronomic regions: NE = Northeast; NC = North Central; Trans = Transition; SE = Southeast; SW = Southwest; UW/Mtn = Upper West/Mountain; Pac = Pacific. y Within a row, values followed by the same letter are not significantly different from one another. Letters denote significance at the 90% confidence level. The percentage of golf facilities that do not pay for water ranges from a high of 64% in the Transition agronomic region to a low of 18% in the Southwest agronomic region. The large range in annual average irrigation water expenditure, water cost per irrigated turf acre, and the percent of golf facilities that do not pay for water can be attributed to the amount of precipitation and the relative abundance of surface and/or groundwater in each region. In agronomic regions where precipitation and surface and/or groundwater are abundant, water costs are low, and where precipitation and surface and/or ground water are scarce, water costs are high. Since 2001, on golf facilities that pay for water, the amount spent for water has increased for 53% of golf facilities, stayed the same for 43%, and decreased for 4% (Table 9). Irrigation water cost was most likely to have increased for golf courses in the Southwest and Pacific regions and stayed the same in the Northeast, Transition, and Southeast (Table 9). The average percent increase in water cost was highest in the North Central agronomic region at 45% and lowest in the Transition region at 15%. The percent of golf facilities that experienced a decrease in irrigation water cost ranged from 6% in the Transition, Southwest, and Upper West/Mountain to 2% in the Pacific agronomic region. The average percent decrease in water cost was greatest in the Pacific agronomic region at 76% and lowest in the Northeast agronomic region at 23% (Table 9). Table 9. Changes in water cost on United States golf facilities since 2001.
x Agronomic regions: NE = Northeast; NC = North Central; Trans = Transition; SE = Southeast; SW = Southwest; UW/Mtn = Upper West/Mountain; Pac = Pacific. y Within a row, values followed by the same letter are not significantly different from one another. Letters denote significance at the 90% confidence level. Water Source Golf facilities use many different irrigation water sources, with some facilities using multiple irrigation water sources. On a national average, open water of lakes or ponds (52%) and wells (46%) are the two most common sources of irrigation water (Table 10). The sources of irrigation water for golf facilities vary by agronomic region. Open water is the most common irrigation water source for 74% of golf facilities in the Transition agronomic region but is used by only 8% of golf facilities in the Southwest agronomic region. Table 10. Percentage of golf courses that use various types of irrigation water sources in the USA and within each agronomic region.
x Agronomic regions: NE = Northeast; NC = North Central; Trans = Transition; SE = Southeast; SW = Southwest; UW/Mtn = Upper West/Mountain; Pac = Pacific. y Within a row, values followed by the same letter are not significantly different from one another. Letters denote significance at the 90% confidence level. Wells are a fairly common irrigation water source in all agronomic regions, but their use is highest in the North Central region, where 62% of golf facilities use wells as one of their water sources. Rivers/streams/creeks are used as an irrigation source on 28% of golf facilities in the Upper West/Mountain agronomic region and on 22% of golf facilities in the Northeast agronomic region, significantly more than in other agronomic regions. A municipal water supply is used as an irrigation water source on 31% of golf facilities in the Southwest agronomic region and 25% of golf facilities in the Pacific agronomic region, more than in the other agronomic regions (Table 10). Recycled water was a significantly more important water source for golf facilities in the Southwest (37%) than in any other agronomic region. The Southeast agronomic region ranked second in its use of recycled water, with 24% of golf facilities using it for irrigation. Use of recycled water for irrigation was significantly lower at golf facilities in the Northeast (3%), North Central (3%), and Transition (4%) agronomic regions. In the Southwest, canals served as an irrigation water source for 18% of golf facilities, significantly more than in all other agronomic regions. In 2005, brackish water, on-site desalinization plants, and other water sources were minor sources of irrigation water for golf facilities (Table 10). Average 18-hole golf facilities annually paid an average of $52,400 for municipal water, $44,400 for recycled water, $6,900 for well water, $4,600 for water from a river/stream/creek, and $3,900 for water from open water. The similar cost for municipal water and recycled water underscores the value of all water sources in many regions of the country. Too few responses were received to determine an average cost of water from canals, brackish water, on-site desalinization plants, and other water sources. Recycled Water Use In the United States, recycled water is used as a source of irrigation water by 12% of golf facilities. Private and public golf facilities showed no difference in recycled water use, but golf facilities with a greater number of holes and higher maintenance budgets used a higher percentage of recycled water for irrigation (Table 2). The most common reason cited for not using recycled water for irrigation was the lack of a source by 53% of respondents. Other reasons for not using recycled water as an irrigation water source were: not necessary given other water resources (29%); no infrastructure to deliver available recycled water (13%); recycled water was too expensive (1%); recycled water was of poor quality, making it too difficult to grow turf (1%); and other (3%). A survey of golf courses in Texas by Dixon and Ray (3) yielded 40 responses from golf courses using recycled water, and their results indicated initial cost or cost to retrofit the irrigation system to accommodate recycled water and availability of recycled water were the major limitations for recycled water use. Water-Quality Characteristics The number of holes at a golf facility significantly affected the likelihood of water testing, with 52% of 27-hole golf facilities, 46% of 18-hole golf facilities and 18% of 9-hole golf facilities having analyzed their irrigation water in 2003. Comparing private and public golf facilities showed a significantly higher percentage of private facilities (52%) than public facilities (33%) have had their irrigation water analyzed since 2003. When golf facilities were categorized by the size of their maintenance budget, irrigation water had been analyzed by 74% of facilities with a maintenance budget of over $1,000,000, 51% with a budget of $500,000 to $1,000,000, and 24% of facilities with a budget of less than $500,000. Since 2003, irrigation water has been analyzed by significantly more 18-hole golf facilities in the Southwest agronomic region (68%) than in any other agronomic regions. Significantly more irrigation water analyses have been conducted by golf facilities in the Southeast agronomic region (58%) and golf facilities in the Upper West/Mountain region (56%) than in all the other agronomic regions. Significantly more golf facilities in the Pacific (45%) and North Central (40%) agronomic regions have conducted an irrigation water analysis than in the Transition (37%) and Northeast (32%) regions. Irrigation water quality, as determined by total dissolved solids (TDS), sodium absorption ratio (SAR), pH, and residual sodium carbonate (RSC) (5), was poorest in the Southwest agronomic region, and TDS and SAR were significantly higher in the Southwest than in all other agronomic regions. In the Southwest and Upper West/Mountain regions, pH was significantly higher than in all the other agronomic regions. Residual sodium carbonate was significantly higher in the Pacific, Southwest, Transition, and Northeast regions than in the other agronomic regions. Water quality was best in the Northeast and Transition regions (Table 11). A survey of irrigation water quality of 35 golf courses in southeastern Pennsylvania by Fidanza et al. (4) showed a mean TDS of 226 ppm, a mean SAR of 0.7, a mean pH of 6.9, and a mean RSC of 0.02, which were similar to the values from this survey for the Northeast agronomic region. Table 11. Water characteristics for golf facilities in the USA and within each agronomic region.
x Agronomic regions: NE = Northeast; NC = North Central; Trans = Transition; SE = Southeast; SW = Southwest; UW/Mtn = Upper West/Mountain; Pac = Pacific. y Within a row, values followed by the same letter are not significantly different from one another. Letters denote significance at the 90% confidence level. Forty-six percent of all golf facilities either treat their irrigation water or deliver one or more products through their irrigation system. Golf facilities in the Southwest agronomic region are most likely (72%) and golf facilities in the Transition are the least likely (30%) to treat their irrigation water or deliver products through their irrigation systems (Table 12). Wetting agents (34%) and fertilizer (23%) are the products most commonly delivered via an irrigation system. Acid-injection systems and sulfur burners are the most common water treatments used on golf facilities (Table 12). Table 12. Water treatments or products delivered through irrigation systems at golf facilities in the USA and within each agronomic region.
x Agronomic regions: NE = Northeast; NC = North Central; Trans = Transition; SE = Southeast; SW = Southwest; UW/Mtn = Upper West/Mountain; Pac = Pacific. y Within a row, values followed by the same letter are not significantly different from one another. Letters denote significance at the 90% confidence level. Irrigation System Characteristics Nine-hole public golf facilities with a maintenance budget of less than $500,000 are significantly more likely to have a manual irrigation system than other types of golf facilities. Conversely, 18- and 27-hole private golf facilities with a maintenance budget greater than $1,000,000 are significantly more likely to have fully automated irrigation systems (Table 13), including a master (central) controller and field (satellite) controllers with controls that can be operated remotely. A semiautomatic system has only field controls, and a manual system has no automation in the control system. Table 13. Percentage of United States golf facilities that have fully or semi-automated, manual, or other types of irrigation systems by golf facility characteristic.
x Within a column and golf facility characteristic, values followed by the same letter are not significantly different from one another. Letters denote significance at the 90% confidence level. Averaged over all types of golf facilities, main irrigation lines are 15.6 years old, lateral lines 14.3 years old, irrigation heads and pump stations 10.3 years old, pumps 9.3 years old, field controllers 8.5 years old, and master controllers 6.5 years old. The younger age of field and master controllers reflects the importance of precision management and conservation of water and advances in electronics and computers to improve control systems. The older age of main and lateral lines reflects the longer life span of pipes and the difficulty and expense of installing new lines. The American Society of Golf Course Architects estimated life span of an irrigation control system is 10 to 15 years and 10 to 30 years for PVC pipe under pressure (1). Irrigation system audits provide a means to improve the performance and efficiency of an irrigation system. For 18-hole golf facilities, 8% have had an irrigation system audit conducted by a qualified professional since 2001, and significantly more private (11%) than public facilities (6%) have conducted an audit. When 18-hole golf facilities are categorized by maintenance budget, 16% of those with a budget greater than $1,000,000, 8% with a budget of $500,000 to $999,999, and 5% with a budget less than $500,000 have conducted an irrigation system audit, with the percentage of facilities in each category significantly different from the percentage in the other budget categories. The percentage of 18-hole golf facilities that have conducted an irrigation system audit is significantly higher in the Southwest (15%) than in the Southeast (11%). The percentages for both these regions are significantly higher than the 5% to 7% of 18-hole facilities that have conducted irrigation system audits in the other agronomic regions. For 18-hole golf facilities that have conducted an irrigation system audit, the course average distribution uniformity is 72%. The distribution uniformity was 77% on greens, 76% on fairways, and 73% on tees. Kah and Willig (8) reported in 1993 that distribution uniformity values on golf courses range from 50% to 90% and average 70% to 85%. Since 2001, the most common improvement made to irrigation systems on 18-hole golf facilities has been the installation of new irrigation heads at 70% of the facilities. New nozzles (59%) and the addition of sprinkler heads (54%) were the other two most common improvements to the irrigation system. The least common improvements to irrigation systems at 18-hole golf facilities were new main lines (8%), new lateral lines (19%), and new pump stations (24%) (Fig. 2). The most common improvements enhance the performance of the irrigation system and are less disruptive to the golf course and less expensive than the least common improvements.
Water Management and Conservation Nearly all 18-hole golf facilities use one or more techniques to aid in scheduling irrigation. The most commonly used irrigation scheduling techniques, followed by the percentage of 18-hole golf facilities that use that technique, are: observations of turf (97%), soil moisture observations (82%), short-term weather forecasts (49%), evapotranspiration rate from a weather service (18%), evapotranspiration rate from an on-site weather station (17%), long-term weather records (6%), soil sensors (3%), other (6%), and none (1%). Youngner et al. (14) reported water savings of 41% to 55% when using soil sensors (tensiometers) and 24% when using an evaporation pan to schedule irrigation compared to irrigation scheduled by a turf manager on warm-season grass research plots without a loss of turfgrass quality. Currently, only 48% of respondents use evapotranspiration or soil sensors to help schedule irrigation. These data indicate an opportunity for the golf industry to reduce water use by using irrigation scheduling techniques that are less subjective than observations of turfgrass and/or soil. An average 18-hole facility is likely to use more than one irrigation scheduling technique. Written drought management plans are most common at private, 27-hole facilities with a maintenance budget greater than $1,000,000 (Table 14). Significantly more 18-hole golf facilities in the Northeast agronomic region (28%) and significantly fewer 18-hole golf facilities in the North Central region have written drought management plans (Table 15). Table 14. The percentage of golf facilities that have a written drought management plan, and are subject to a recurring annual water allocation by golf facility characteristic.
x Within a row, values followed by the same letter are not significantly different from one another. Letters denote significance at the 90% confidence level. Table 15. The percentage of 18-hole golf facilities that have a written drought management plan, are subject to recurring annual water allocation, and are subject to temporary additional mandatory water restrictions more stringent than normal water allocation.
x Agronomic regions: NE = Northeast; NC = North Central; Trans = Transition; SE = Southeast; SW = Southwest; UW/Mtn = Upper West/Mountain; Pac = Pacific. y Within a row, values followed by the same letter are not significantly different from one another. Letters denote significance at the 90% confidence level. Private 27-hole golf facilities with a maintenance budget greater than $1,000,000 are most likely to be subject to a recurring water allocation (Table 14). A recurring annual water allocation was significantly more likely to be required for 18-hole golf facilities in the Southwest (40%), Upper West/Mountain (39%), and Southeast (36%) agronomic regions (Table 15). Mandatory water restrictions that are more stringent than normal recurring annual water allocations have been imposed on 16% of 18-hole golf facilities at least once since 2001. These additional mandatory restrictions on 18-hole golf facilities were significantly more common in the Northeast (33%) and Upper West/Mountain (31%) agronomic regions (Table 15). Since 1996, superintendents at 18-hole golf facilities have used a wide array of techniques to conserve water. The most common water-conservation practices and the percentage of 18-hole golf facilities following those practices are: application of wetting agents (92%), hand-watering (78%), and keeping turfgrass drier than in the past (69%) (Fig. 3). Superintendents commonly used more than one technique to conserve water. Of the water-conservation techniques used at 18-hole golf facilities, reduction of irrigated acres and the use of automatic rain shut-off switches for irrigation systems were the only two required by state or local regulation.
Conclusions Water is a precious resource that must be used judiciously by everyone, including the golf industry. Comparing data from this survey with data from surveys of other water uses shows that golf courses are responsible users of water. Total annual water use for all golf facilities nationwide in 2005 is estimated at 2,312,701 acre-feet (Table 6). The United States Geologic Survey (USGS) estimated total water withdrawals in the USA in 2000 at 457,000,000 acre-feet and agricultural water withdrawals including golf courses at 153,000,000 acre-feet (6). Comparing the data collected in this survey to data from the USGS survey shows annual water use on United States golf courses is 0.5% of the estimated annual total withdrawals for the country and is 1.5% of the estimated annual total agricultural water withdrawals. A survey of Colorado golf courses in 2002 revealed that approximately 15.6 billion gallons of water per year or 47,875 acre-feet were used to irrigate 19,800 acres of turfgrass (11). The amount of water used to irrigate golf courses in Colorado was less than 0.33% of the state’s annual water consumption, which is similar to the 0.5% of estimated US annual total water use that we calculated with data from this survey and a USGS survey. An irrigation system audit is an effective tool to determine whether water is being applied uniformly. Our survey reported an average distribution uniformity of 72%. This is slightly higher than the 67% distribution uniformity measured on six golf courses in the Salt Lake City, UT, area (6). Jackson et al. conducted an irrigation audit of 311 large properties, including six golf courses, in the Salt Lake City area and found that golf courses had the highest irrigation system distribution uniformity at 67%. Other large properties and their average irrigation system uniformity were churches 60%, businesses 57%, public facilities 57%, homeowner associations 56%, schools 56%, apartment complexes 55%, and parks 52% (7). These distribution uniformity data compare to an average distribution uniformity of 70% to 85% measured on golf courses (8). All water users, including golf courses, must use water efficiently. Although many golf courses use water efficiently, these survey results point out two areas, in particular, that need improvement: the use of evapotranspiration estimates and soil sensors to schedule irrigation, and use of irrigation audits to improve irrigation distribution uniformity. These data provide an accurate portrayal of golf course water use to guide industry agronomic and environmental initiatives and establish a baseline that can be compared to data from future surveys to monitor industry change. Acknowledgments The authors thank The Toro Foundation (Minneapolis, MN) for providing a grant to help fund this research. Literature Cited 2. Christians, N. E. 1998. Fundamentals of Turfgrass Management. Ann Arbor Press, Chelsea, MI. 5. Harivandi, M. A. 1999. Interpreting turfgrass irrigation water test results. Calif. Turf. Cult. 49:1-6. 7. Jackson, E. K., Lopez, R. M., Leigh, J. R., and Hinton, A. C. 2005. Audit data summary of large water users, 2004. Ext. Publ. AG/Irrigation/2005-01. Utah State Univ., Logan, UT. 8. Kah, G., and Willig, W. C. 1993. Irrigation management by the numbers, part I: Put your system to the test. Golf Course Irrig. Fall:8-13. 11. NGF. 2007. Golf facilities in the U.S., 2007 Edn. Nat'l. Golf Foundation (NGF), Jupiter, FL. 12. Shurtleff, M. C., Fermanian, T. W., and Randell, R. 1987. Controlling Turfgrass Pests. Prentice-Hall, Englewood Cliffs, NJ. 14. Youngner, V. B., Marsh, A. W., Strohman, R. A., Gibeault, V. A., and Spaulding, S. 1981. Water use and turf quality of warm-season and cool-season grasses. Pages 251-257 in: Proc. of the Int'l. Turfgrass Res. Conf. No. 4. Univ. of Guelph, Canada. Appendix A: The Survey Golf Course Environmental Profile - Water Use and Conservation Survey (PDF). |
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