A New Era for Irrigation (1996)

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Irrigation Today Less than 1 percent of the nation's farmland was irrigated in 1900, but by 1982 irrigation accounted for 1 of every 8 acres under cultivation and nearly $4 of every $10 of the value of crop production (U.S. Department of Agriculture, 1986~. This transition was driven by economic change: in the late nineteenth century, western promoters turned to irrigation when mining, open range cattle, and dry farming economies proved unable to sustain western settlement (Webb, 1931~. During this period, foundations were laid to support irrigation water rights laws, advances in engineering, mutual water district organization and fi- nancing and these supported early irrigation in areas such as California, Colo- rado, and Utah. However, irrigation did not begin to expand rapidly until after Congress passed the Reclamation Act of 1902, which established the Reclama- tion Service (now the Bureau of Reclamation) to assist in developing the West through irrigation. The federal role in water development expanded further in the 1930s as water development was also used to create new jobs. By the end of World War II, four federal agencies the U.S. Army Corps of Engineers, the Bureau of Recla- mation, the Tennessee Valley Authority, and the Soil Conservation Service (now the Natural Resource Conservation Service of the Department of Agriculture) NOTE: There are many sources of data that describe the status of irrigation in the United States. However, the methods used to gather and interpret statistics vary significantly, resulting in disparities among the different sources. Because many references and sources were used in developing this chapter, there are occasions where values may not be fully compatible. 46

IRRIGATION TODAY 47 had expanded their roles in the use and development of water resources (National Research Council, 1992a). After World War II, irrigated agriculture expanded rapidly in the far West and the central Great Plains. More recently, supplemental irrigation has become important in the East, Southeast, and Midwest. Irrigated agriculture remained an engine of western development until the 1970s. How- ever, increasing development costs, reduced government financing, increasing demand for municipal and industrial water supplies, diminishing sources of water supply, and a growing concern for the environment have forced water managers and planners to begin rethinking traditional approaches to water management (National Research Council, 1992b). This chapter provides background information about the current status of irrigation the amount of land irrigated, types of crops, water withdrawals, and consumptive use. It gives an overview of the technologies used and the econom- ics of irrigated systems, including water pricing and marketing. It highlights key issues in the relationship of irrigation to the environment and introduces an increasingly important force in the water arena: the turfgrass sector. It also highlights another element certain to be key in the future irrigation on Indian lands. Together, these discussions are designed to provide a quick review of irrigation today and thus set the stage for the committee's foray into irrigation's future. Readers already well-versed in the status and trends of irrigation today are encouraged to proceed to Chapter 4, where the committee explores the deeper cause and effect relationships that underlie the statistics. IRRIGATED AGRICULTURE Irrigated Land in Farms Irrigated agriculture occurs on just 14.8 percent of the harvested cropland and yet produces 37.8 percent of the value of crops (Figure 3.1~. The relatively Irrigation accounts for 4.8% of the land in farms (total farm acreage = 964 million acres) Irrigation accounts for 14.8% of the total harvested cropland (282 million acres) Irrigation accounts for 37.8% of the total crop value ($68.8 billion) FIGURE 3.1 Irrigation and farm production (1987 Census of Agriculture). Source: Bajwa et al., 1992.

48 A NEW ERA FOR IRRIGATION arge economic contribution of irrigated agriculture can be explained by the sigher yields obtained for irrigated crops, the tendency to irrigate high-valued Indoor specialty crops, and the improved product quality and consistency. In 1959, 9 percent of all farms reported some irrigated land. By 1987, that Hare had risen to 14 percent. During the 1980s, the total number of irrigated acres and irrigated acres per farm fluctuated considerably because of the tempo- ~ary idling of land associated with annual commodity program acreage restric- ions. Most (90 percent) of the nation's irrigated land is harvested cropland, but many of the mountain states irrigate pasture and land from which wild hay is cut ;o sustain livestock through the winter. In the United States, irrigation is used mainly in the 17 western states, plus Arkansas, Florida, and Louisiana (see Box 3.1~. These 20 states account for 91 Percent of all U.S. irrigated acreage and 82 percent of all irrigated farms. The 17 western states alone contain over 81 percent of the total irrigated land; 85 to 90 Percent of total water withdrawn in the West is used for irrigation. Although rrigated cropland provided a substantial portion of national farm income in 1987, here were only about 292,000 individual irrigators, 14 percent of all farmers. Our-fifths of the irrigators were located in the 17 western states. The drought years of the 1950s and the development of centrifugal pumps and more economical power sources stimulated irrigation development in the southern Great Plains, where ground water is pumped from the Ogallala aquifer. With the advent of the center pivot sprinkler irrigation systems, and with ground hater readily available, irrigation expanded rapidly in the central Great Plains luring the 1960s and 1970s. Irrigation also expanded in humid southeastern states as a way to provide dependable and timely water. In California and the Pacific Northwest, irrigated areas also expanded during the 1950s and 1960s as many irrigation projects constructed by the Bureau of Reclamation and local ntities were completed and put into service. The total irrigated area essentially stabilized in the 1980s due to a combination of low farm commodity prices, ncreased energy costs, and declining water resources. The percent of harvested ,ropland irrigated by state is given in Figure 3.2 (Bajwa et al., 1992~. Figure 3.3 shows trends for irrigated land in farms and water applied per acre From share of total acreage irrigated are rice (100 percent), orchards (81 percent),

IRRIGATION TODAY \ -. f . . ....................... i...... 1 . ~, I.................................... /............................................ /.............................................. ............................. .............. C ~, .................... 2.2.2.2.2.2.2.2.2.2.2.""".2.2.2.2.2.""""". ~ ,,,,,,,,,,,, i'.'.'. .2.2.2.2.2.2.2. .2.2.2.2.2 \ ................................................................. ............ '.'.'.'.'.'."""""""""""""""""\~8 .2.2.2.2.2.2.2.2.2.2.2.2.2.2.2.2.2.2.2.2.'.'.'.'.'.'.'.'.'.'.'.'. ' ~\~) .:.:.:.:.:.:.:.:.:.:.:.:.:.:.:.:.:.:.:.:.:.:.:.:.:.:.:.:.:.:.:.:.: ~I: ~ mu:, t"""""""""""""""""""""""r 1 \ ~1""""""""""""""""""2"' '554~\ `` J - \ ~N ` _ ~ ) ~1 "'1 1 ' ~ it_ I I Less than 1 1 l 25-49 1-4 49 50-79 I _. I 1 5-24 ~80-100 FIGURE 3.2 Percentage of harvested cropland irrigated by state, 1987. Source: Bajwa et al., 1992. vegetables (64 percent), and cotton (38 percent). Crops with the largest total irrigated acreages are hay, corn for grain, wheat, and cotton (U.S. Department of Agriculture, 1986~. While much smaller percentages of grain acreages are irri- gated (e.g., 14 percent of harvested core, 13 percent of sorghum, and 7 percent of wheat), the combination of improved yields on irrigated farms and the increase in the relative acreage devoted to irrigation accounted for 28 percent of the national increase in corn production, 20 percent for sorghum, and 12 percent for wheat from 1950 to 1977 (Frederick and Hanson, 1982~.  WATER USE FOR IRRIGATION Irrigation water typically is measured in terms of withdrawals or consump- tive use. Withdrawals represent the amount of water diverted from a surface source or removed from the ground. Consumptive use is a measure of water lost to the immediate water environment through evaporation, plant transpiration, incorporation in products or crops, or consumption by humans and livestock. Consumptive use in agriculture is primarily crop evapotranspiration, which is influenced heavily by climate and the types of crops irrigated. Reasonably accu

so Million acres 50 48 ~6 ~8 A NEW ERA FOR IRRIGATION Inches r ~- ~ - - r ~ IL-e ~ _ ~ u ~-- e of b ·, ~ l ! ~ ~ r v ~ ~ v a~_r lob #~ ~ ~-~ d~ 51~ IN- L ~ I~ ~- ~ ~ 1 · I Irrigated land in farms 1/ r (left scale) / ~ ~ ~ a- - ~ Water applied 2/ (right scale) 36 .; B~-L l --L,-~.l., J- I - -I ,.~ ,~ ~ ~llIs ~i ~ B ~1d~4- ~l ~ . ~It~ --1~ - ~r--l--l L8 - ~8 1972 1976 1980 19~ 1988 i992 1996 I/Based on Census and annual USDA data. 21Based on FRIS and changes in state/crop area 24 FIGURE 3.3 Trends in irrigated acres between 1969 and 1993. Source: U.S. Department of Agriculture, 1993. rate estimates of water withdrawn for irrigation can be made if the acreage irrigated, water application rates, and conveyance losses are known. However, reliable estimates for consumptive use and conveyance loss are not currently available. Thus the available estimates are rough approximations of actual condi- tions. These estimates reflect the importance of the four influential factors: irriga- tion technology, crop prices, annual commodity program acreage restrictions, and weather. Relaxed acreage restrictions, improved irrigation technology, and high crop prices in the 1970s accelerated irrigation development, increasing total irrigated area from 38 million acres in 1972 to 52 million acres in 1981. Irrigated

51 TABLE 3.1 Irrigated Area in the United States Region1987 (thousand acres)1992 (thousand acres)Change (%) Alabama8482-2 Arizona9149565 Arkansas2,4062,70212 California7,5967,5710 Colorado3,0163,1705 Connecticut76-19 Delaware61622 Florida1,6231,78310 Idaho3,2193,2601 Illinois20832858 Indiana17024142 Iowa9211625 Kansas2,4632,6809 Kentucky3828-27 Maine61069 Maryland515712 Massachusetts2020-1 Michigan31536817 Minnesota3543705 Mississippi63788339 Missouri53570933 Montana1,9971,976-1 Nebraska5,6826,31211 Nevada779556-29 New Hampshire32-41 New Jersey9180-12 New York5147-8 North Carolina138113-18 North Dakota16818711 Ohio3229-9 Oregon1,6481,622-2 Pennsylvania3023-22 Rhode Island33-15 South Dakota3623713 Tennessee3837-2 Texas4,2714,91215 Utah1,1611,143-2 Vermont2216 Virginia7962-22 Washington1,5191,6418 West Virginia33-12 Wisconsin28533116 Wyoming1,5181,465-4 Total (43 states)43,67146,3196.1 Source: U.S. Department of Commerce, 1994.

52 A NEW ERA FOR IRRIGATION acres then dipped from 1983 to 1987, primarily as a result of acreage restrictions in commodity programs. Water applied per acre has declined from about 25 inches to less than 22 inches. According to the 1992 Census of Agriculture (U.S. Department of Com- merce, 1994) the total 1992 irrigated area was 46.3 million acres, up 2.6 million acres from 1987 (Table 3.1~. During this period, there was no increase in irri- gated acres in the West from surface water. The increase in irrigation from 1987 to 1992 occurred mostly in the Great Plains region, which relies primarily on ground water. On the other hand, much of the East was dry in 1987, and the return to more normal moisture levels in 1992 diminished a trend toward in- creased irrigation in the East. Irrigated Crops Most major crops are irrigated to some degree, but the number of acres and percentage of acres irrigated vary widely from crop to crop. Crops that have the greatest estimates for consumptive use and conveyance loss are not currently available. Thus the available estimates are rough approximations of actual con- ditions. Water Withdrawals Irrigation is by far the largest consumptive water user in the United States, particularly in the West. The quantity of water withdrawn for irrigation during 1990 was an estimated 137,000 million gallons per day, or 153 million acre-feet, which represents 40 percent of total U.S. freshwater use for all offstream catego- ries. Irrigation withdrawals as well as acres irrigated during 1990 were about the same as during 1985. Water withdrawal and consumptive use information is summarized by water resource region and by state in Tables 3.2 and 3.3, respec- tively. The nine western water resources regions, led by the Pacific Northwest region, accounted for 90 percent of the total water withdrawn for irrigation during 1990 (Table 3.2~. In the eastern regions, most of the water withdrawn for irriga- tion was in the Lower Mississippi and South Atlantic-Gulf regions, which to- gether had about 2,400 million gallons per day more water withdrawn during 1990 than during 1985. Most states rely on a combination of surface and ground water supplies for irrigation purposes (see Table 3.3~. Surface water accounted for 63 percent of total irrigation withdrawals in 1990. States with the highest share of surface water withdrawals include California, Montana, Wyoming, Oregon, Washington, and Utah. Ground water is the primary supply source for irrigation in about half of the states (Table 3.3~. Total ground water withdrawals were largest in California,

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56 A NEW ERA FOR IRRIGATION Texas, and Idaho. Ground water as a share of irrigation withdrawals was highest in Kansas, Mississippi, Arkansas, Oklahoma, and Nebraska. Irrigated agriculture has contributed to declining aquifers in many areas. In 1985, agriculture accounted for 42 percent of all freshwater withdrawals in the United States, or a total of 141 billion gallons per day, of which 97 percent was for irrigation and 3 percent was for livestock production. Freshwater with- drawals for agriculture are used mainly for crop production, with 98.4 percent of surface water and 93.8 percent of ground water used in irrigating cropland (Solley et al., 1988). The trend in water used for all purposes for 5-year intervals from 1950 to 1990 is shown in Table 3.4. Included are withdrawals, source of water, reclaimed wastewater, consumptive use, and instream use (hydroelectric power). Table 3.4 also estimates the percentage increase or decrease in withdrawals between 1985 and 1990. After continual increases in the nation's water use from 1950 to 1980, offstream and instream uses were less during 1985 than during 1980. Total withdrawals were about 10 percent less during 1985 than during 1980, and the 2 percent increase from 1985 to 1990 is the result of increases in surface and ground water withdrawals of 1 and 9 percent, respectively. The fact that the 1990 withdrawal estimates are only slightly higher than the 1985 estimates tends to confirm the overall decline in water use from the peak of 1980. The increase in estimated ground water withdrawals from 1985 to 1990 was partly the result of decreased availability of surface water. Surface water with- drawals for irrigation increased progressively for the years reported from 1960 to 1985 and decreased 6 percent from 1985 to 1990. It is expected that surface water withdrawals in the Pacific Coast and Pacific Northwest will remain at current levels or will decline as reallocations take place from agricultural use to streamflow maintenance to restore anadromous fish populations. Water application varies from about 30 inches per year for crops such as rice and alfalfa to less than 10 inches per year for soybeans (Table 3.5~. The amounts vary from region to region and from year to year depending on climatic condi- tions (especially temperature), precipitation, and irrigation practices. There is no direct annual measure of irrigation water applications, but 5 years of census and postcensus survey data suggest some trends (U.S. Department of Commerce, 1994~. The east-west contrast in application rates has narrowed, with Atlantic states using almost twice as much water per acre in 1988 as in 1969. Despite increasing application rates in the East, national average application rates, as well as application rates for several major crops, have declined. Consumptive Use Consumptive use of fresh water in the United States totaled about 105 mil- lion acre-feet in 1990. Irrigation, the dominant consumptive water use, accounted for 85 million acre-feet, or 81 percent of the U.S. total. Consumptive use as a

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IRRIGATION TODAY 120 100 80 60 40 20 Surface water .................... Ground water 1 1 1 1 1 1:.:.:.:.:.:.: ~ ; 1 . 1 1 1 1 1 1 1 1:.:.:.:.:.:.: t::::::: t:.:.:.:.:.:.: t::::::: t:.:.:.:.:.:.: t::::::: t:.:.:.:.:.:.: t::::::: t:.:.:.:.:.:.: t::::::: t:.:.:.:.:.:.: t::::::: t:.:.:.:.:.:.: t::::::: t:.:.:.:.:.:.: t::::::: l t:.:.:.:.:.:.: l t::::::: l  t:.:.:.:.:.:.: l t::::::: l t:.:.:.:.:.:.: l t::::::: l t:.:.:.:.:.:.: l ...... ,....... ,....... ,....... ,....... ,....... ,....... ,....... ,....... ,....... ,....... ,....... ,....... ,....... ,....... ,....... E:.:.:.:.:.:.:. ,:,:,:,:,:,:,: ............. ....... .............. ....... .............. ....... .............. ....... .,:,:,:,:,:,:,: :,:,:,:,:,:,:, _ . ~.,.,.,. ............... .............. ....... ....... ........ ....... ....... ....... ........ ....... ....... ....... ........ ....... ....... ....... ........ ....... ....... ....... ........ ....... ....... ....... ........ ....... ....... ~- 1950 1955 1960 1965 1970 1975 1980 1985 FIGURE 3.4 Trends in irrigation water use from surface and ground water. Source: Bajwa et al., 1992. 61 percentage of withdrawals was 56 percent for the irrigated sector, compared with 17 percent for public and rural supplies, 16 percent for industries other than thermoelectric, and just 3 percent for thermoelectric. Total consumptive water use for irrigation increased by about 60 percent between 1960 and 1980, reflect- ing the rapid expansion of irrigation in the West (Gollehon et al., 1994~. Irrigation consumptive use in the 20 major irrigation states accounted for 96 percent of the national total. California had the greatest irrigation consumptive use, followed by Texas, Idaho, and Colorado. Combined, these four states ac- counted for nearly half of the total irrigation consumptive use in the United States. Five of the top 20 major irrigation states Arkansas, Florida, Mississippi, Louisiana, and Georgia are in humid areas. Figure 3.4 highlights trends in use of surface and ground water for irrigation. Total water use in irrigated agriculture increased during the period from 1950 to 1980, but declined by 7 percent in 1985 despite continued growth in irrigated acreage nationwide. Reduced water use per irrigated acre reflects lower water applications in humid irrigated areas, a shift to less-water-intensive crops, and a reduction in irrigated cropland in some of the highest-water-using areas. Although surface water use increased slightly in 1985, declines in ground water use were greater than the increases in surface water use (Bajwa et al., 1992~.

62 A NEW ERA FOR IRRIGATION Irrigation Technology Traditional irrigation technologies, such as furrow and border irrigation, rely on gravity to deliver water to crops and require substantial volumes of water over a short period of time. Irrigation using these traditional technologies is typically infrequent (once every 2 to 3 weeks, or even less). Modern irrigation technolo- gies such as sprinkler, center pivot sprinkler, and microirrigation rely on energy and closed systems to deliver water to plants. These technologies allow more frequent and smaller irrigation input, improve irrigation distribution uniformity, and reduce water losses in deep percolation and runoff. In essence, the output produced with a given amount of water diverted is increased with these modern technologies. Surface irrigation is still the most common form of irrigation in most states, particularly in the West, but sprinkler irrigation has been increasing rapidly since the 1950s and is used for field crops, fruits, and vegetables. The acreage of sprinkler irrigation increased by 9 percent from 1984 to 1988. Surface irrigation acreage remained almost level during the same period, which allowed sprinkler systems to increase from 37 percent of all systems in 1984 to 39 percent in 1988. The availability of aluminum and plastics was a significant factor in making sprinkler irrigation systems practical and economical. Sprinkler technology has had a great impact on agricultural production in the West and the Midwest. In contrast, lands on the Mississippi Delta continue to be irrigated with traditional gravity-powered technology. For example, in Missis- sippi, where water is inexpensive, furrow irrigation is the principal system. Drip irrigation, which is spreading very quickly in Florida and California, was introduced in the United States in the early 1970s and is currently in use on 1.5 million acres (Boggess et al., 1993~. The technology tends to be adopted with high-value fruit and vegetable crops in locations with sandy soils, uneven terrain, and high water costs. Table 3.6 presents regional distributions of irrigated acre- age by technology for five periods from 1960 to 1985. There is a significant shift occurring in irrigation technology for crops and turf. The transition is to sprinkler and microirrigation. Surface irrigation is being modernized by laser leveling and the adoption of surface automation. Electronic controllers and sensors improve the control and management of irrigation sys- tems. The key forces for adopting new technology are labor availability and cost, energy, limited water availability, and environmental concerns. The constraints to adoption are availability of capital, low-cost existing irrigation systems, user- unfriendly technology, limited management skills, and institutions that fail to provide incentives to conserve water. Irrigation scheduling is an important technology for the effective use of limited resources. The monitoring of soil water with tensionmeter, gypsum blocks, neutron probles, and other sensors have been developed but slow to be adopted. Consultants are often providing scheduling services which include the

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64 A NEW ERA FOR IRRIGATION use of soil probes for the real-time measurement of soil water. A constraint for adopting computer irrigation scheduling programs is the time required to input data. There is a need for user-friendly programs and cost-effective methods to automatically collect data and minimize the hand entering of data. The development of new technology for improved irrigation systems had been accomplished by many entrepreneurial and relatively small specialized com- panies. Often, new systems and management technology is developed by part- nerships between the irrigator, industry, consultants, entrepreneurs, and/or state and federal researchers. The federal government is encouraging cooperative research and development agreements for enhancing the technology transfer of new concepts and systems. Demonstration projects and cost-sharing programs for target problem areas provide for improvement of water use in critical areas. ECONOMICS OF IRRIGATED AGRICULTURE Irrigated yields exceed those for dryland farming by an average of 54 percent for corn grown for grain, 97 percent for wheat, 33 percent for soybeans, and 67 percent for cotton (U.S. Department of Agriculture, 1986) (Table 3.7~. Irrigated farms tend to be more highly capitalized than nonirrigated farms. They produce significantly more crop and livestock value per farm and have higher expendi- tures for agricultural chemicals, energy, and labor. The average irrigated farm has over twice as much invested in land and buildings and twice the value of machinery and equipment as nonirrigated farms. Thus irrigated agriculture is more directly affected by a changing economic and financial environment. As water costs rise, it becomes necessary to economize on water use and to select those agricultural enterprises that can be profitable with higher cost water (McNeely and Lacewell, 1978~. The value of water to agriculture is dependent on the crops produced, crop response to water, crop prices, energy costs, soil productivity, and other production costs. Irrigation Water Prices and Costs The prices of most agricultural inputs are established in markets, where prices indicate relative scarcity through supply and demand. In contrast, irriga- tion water prices are typically not set in a market. Water prices usually reflect only the cost of supplying water and generally do not convey market signals. Irrigation water costs vary widely, reflecting different combinations of water sources, suppliers, distribution systems, and other factors (Gollehon et al., 1994~. The costs of providing on-farm surface water are relatively low. On-farm surface water pumps generally lift water less than 20 feet, resulting in low energy costs of $2 to $ 15 per acre-foot. Initial expenditures for surface water pumps can vary greatly depending on farm-specific conditions, but most systems cost $3,000 to $10,000 (Gollehon et al., 1994~.

IRRIGATION TODAY TABLE 3.7 Yields on Irrigated Lands as a Percentage of Nonirrigated Yields, 1984 65 U.S. Average 20 Principal Irrigated Statesa Corn for grain 154 201 Corn for silage 162 150 Sorghum 127 182 Wheat 197 197 Barley 203 208 Soybeans 133 138 Other beans 133 131 Rice - - Alfalfa 163 176 Other hay 119 127 Cotton 167 187 Sugar beets 121 Tobacco 120 Potatoes 150 195 a Includes the 17 western states plus Arkansas, Florida, and Louisiana. Source: Calculated from data in U.S. Department of Agriculture, 1986, p. 21. TABLE 3.8 Labor Requirements and Capital Costs for the Various Irrigation Methodsa Labor requirement Capital Costsb System (in/acre-irrigation) ($/acre) Surface Border 0.2-1.0 120-400 Furrow 0.4-1.2 160-500 Corrugation 0.4-1.2 100-200 Level basin 0.1-0.5 200-500 Sprinkler Fixed Solid set portable 0.2-0.5 400-120t Permanent 0.05-0.1 400-120t Periodic move Hand move 0.5-1 .5 100-300 End tow 0.2-0.5 180-350 Side roll 0.2-0.7 180-350 Moving Traveler 0.2-0.7 200-400 Center pivot 0.05-0.15 200-400 Linear move 0.05-0.15 300-500 Micro Drip 0.15 250-1000 Subsurface 0.15 250-1000 Bubbler 0.15 250-1000 Spray 0.15 250-1000 a Modified from Turner and Anderson (1980) and Lord et al. (1981). b Excluding cost of water supply, pump, or power unit. Source: Council for Agricultural Science and Technology, 1988.

66 A NEW ERA FOR IRRIGATION Production costs associated with ground water pumping are generally higher and reflect both the variable cost of extraction and the fixed cost of access. Total energy expenses for irrigation pumping reached $1.05 billion in 1988, up 5 percent from 1984. Average expenditures per acre were slightly lower in 1988 than in 1984, reflecting shifts to more efficient application systems and changes in the mix of irrigated crops. Of the five types of energy used for pumping irrigation water electricity, natural gas, liquefied petroleum (LP) gas, diesel, and gasoline electricity (56 percent), diesel (21 percent), and natural gas (17 percent) dominated in 1988. Electricity and natural gas declined in importance, while the use of diesel grew by 4 percent between 1984 and 1988. Average energy expenditures by state range from $11 to $105 per acre (Gollehon et al., 1994~. The major considerations in selecting an irrigation system involve capital and operating costs, crops) to be irrigated, and expected crop yield and quality. Ranges of installed capital costs for the various types of irrigation systems are given in Table 3.8. The increase in crop returns over the useful life of a system must be great enough to repay the capital and annual operating costs. Labor and energy are the two major components of operating costs. Labor requirements for irrigation systems vary greatly. Automated systems, such as automated microirrigation and center pivot systems, have relatively low labor requirements. Labor requirements for the main irrigation methods tabu- lated by Turner and Anderson (1980) and Lord et al. (1981) are given in Table 3.8. Annualized costs are not shown because of the wide range in the expected life of the various systems or system components. The data do show the large differences in capital costs encountered because of differences in water sources, field shapes and topography, soils, and large differences in labor requirements because of automation. More than 60 percent of the West's irrigated lands use gravity to distribute water. Sprinkler irrigation systems, used on about 36 percent of the West's irrigated lands, tend to be considerably more expensive than gravity systems. Center pivot systems, for instance, cost more than $300 per acre installed (three times more than gravity systems) and about $15 for energy for each acre-foot applied. On the other hand, center pivots require very little labor to operate. Mobile trickle systems that attach trail lines with emitters to center pivots or other mobile sprinkler systems have been introduced into the High Plains to reduce evaporation losses and energy use (Frederick and Hanson, 1982, pp.158-165~. In the High Plains, a large number of LEPA (low-energy precision application) systems were also installed in place of higher-pressure sprinkler systems (Bryant and Lacewell, 1988~. Economic factors, especially crop and energy price levels, will be important to the future growth of irrigated agriculture. Because their yields and production costs are generally higher, irrigators' profits are more sensitive than those of other farmers to agricultural prices. High crop price levels encourage yield

IRRIGATION TODAY 67 increasing investments, of which irrigation is an important option. On the other hand, high energy prices are likely to affect irrigators more adversely than other farmers. Rising real crop price levels can offset higher water costs and encourage additional ground water pumping. But the lure of additional profits from irriga- tion would not alter the trend for more of the region's water to flow to municipali- ties and industries where water values are much higher than in irrigation. Nor would it do much to increase the flow of public funds for irrigation projects that are criticized for their adverse impacts on the environment and instream water uses as well as for their questionable economics. Higher crop prices, however, would make irrigators more inclined and better able to respond to rising water costs with investments designed to increase the return to water (Frederick, 1988a). Value of Irrigation Water and Water Marketing The value of water in agriculture (principally for irrigation) is often esti- mated by calculating the value of the last unit applied. The value of irrigation water provides a base of comparison to the value of water in other uses. The Office of Technology Assessment (1983) indicated that the value of an acre-foot of water used in irrigation ranges from $9 to $103 (Boggess et al., 1993~. Typi- cally, horticultural crops and other high-value crops are associated with the high- est value of water, while pasture and alfalfa are associated with the lowest values. The value of water in agriculture is generally less than in industrial and municipal uses, and the price elasticity of demand for industrial and municipal water is more inelastic than that for agriculture. This means that when the need for additional supply arises for municipal and industrial users, they can offer higher prices for water than can agriculture (Boggess et al., 1993~. The differ- ence between the value of water in agricultural, industrial, and municipal uses is largely due to the limited use of markets for allocation of water among users. For example, water from reservoirs and transport facilities built by the Bureau of Reclamation is allocated according to water rights based on past use rather than willingness to pay, and trading has been constrained. Because it is so expensive to develop additional water supplies, only the higher-value water uses are likely to be justified economically. The implied average cost of adding an acre-foot to annual water supplies through recom- mended conservation measures is between $1,000 and $2,500. While this cost is not out of line with prices paid for water rights in some areas of the West, it is well above the value of water for most agricultural uses. About 90 percent of the consumptive use of western irrigation water is applied to crops for which the marginal value of water is less than $100 an acre-foot; nearly one-half is for crops with marginal water values of $30 an acre-foot or less (Gibbons, 1986~. Thus the present value of a permanent increase in net water supplies is much less than $1,000 per acre-foot for all but the higher-value crops. The trend in the future

68 A NEW ERA FOR IRRIGATION thus will be toward higher-valued crops for instance, orchard crops and veg- etables rather than hay. Institutional constraints also limit the flow of water to higher and more economically valuable uses. A market-oriented allocation system would allow those with higher-valued uses to bid water away from many lower-valued uses. Such an approach, however, often requires modification in water laws and insti- tutions. For example, in some states such as California and Texas, farmers attracted by offers of high prices are selling water to municipal and industrial users. The higher water values often characteristic of nonagricultural uses have led to predictions that such transfers would lead to the demise of irrigation in large areas. However, such forecasts may not be accurate. Because of the current dominance of irrigation in western water use, large percentage increases in non- agricultural water uses can be met with relatively small percentage reductions in irrigation use. For instance, nearly 90 percent of the consumptive use of western water is for irrigation. Thus a 10 percent reduction in irrigation use would be sufficient to almost double the water available for municipal and industrial uses (Frederick, 1988b). IRRIGATION AND THE ENVIRONMENT The principal environmental issues relevant to irrigation are those concerned with the protection and management of water supplies and water quality. In the last 25 years, the public has become increasingly conscious of and concerned about environmental quality, endangered species, and public health and safety, and of the impacts of agricultural irrigation on these resources. Urban and subur- ban expansion into rural, agricultural regions has also given rise to conflicts over land use, waste disposal, recreational access, chemical use, and other issues. Environmental issues related to water consumption and water quality in land- scape irrigation have become more prominent with the expansion of golf courses and the turfgrass sector generally. The relative significance of environmental issues associated with irrigation varies between regions of the country, but the types of environmental issues confronting irrigation generally are the same coast to coast. Irrigation has been insulated in some ways from direct environmental regula- tion over the past 25 years. Most of the environmental laws and policies adopted in the period from the late 1960s to the early 1980s had little to do specifically with irrigation; rather they evolved in response to concerns over endangered species, wilderness preservation, point sources of contamination, and threats to ambient air and water quality. Some irrigation impacts were exempted explicitly from regulation, such as the exemption of irrigation return flow as an unregulated nonpoint source of pollution under the Clean Water Act. At the same time, laws and institutions pertaining specifically to irrigation had little to say about envi- ronmental issues. Instead, they were designed to advance other social goals such

IRRIGATION TODAY 69 as the settlement of the West, reliability and affordability of irrigation water supplies, stabilization of the agricultural economy through crop payments, assis- tance to individual farmers affected by natural disasters such as drought or pests, and soil conservation. However, the environmental impacts of activities associated with irrigated agriculture have been profound. Irrigation has contributed directly to losses of aquatic habitats and the decline of species that depend on them (Wilcove and Bean, 1994~.2 Runoff from irrigation is a significant source of water pollution in rivers, lakes, and estuaries (National Research Council, 1989~. The potential for conflict between irrigation and environmental goals is in- herent in the fact that water is the limiting resource in irrigation and in aquatic ecosystems. Although irrigation has been largely exempt from the "command and control" environmental regulations applied to other industries, the trend in environmental policy is one of greater focus on, and control of, irrigation activi- ties that have the potential to affect endangered species and their habitat, sensi- tive ecosystems such as wetlands, water quality, and public health. Irrigation's influence on the environment also is receiving public and political scrutiny with the growing concern over the costs of environmental protection and subsidies to natural-resource-based industries. Under the Bureau of Reclamation, repayment requirements for irrigators have been generous, with federal irrigation subsidies averaging in excess of 86 percent of construction costs (Wahl, 1989~. In some cases, federal (or state) subsidized water is used to irrigate lands that in turn grow crops subsidized under federal commodity price support programs. In an era of increased competition for water supplies, and with state and the federal govern- ments struggling with budget constraints, the costs of these programs is being called into question. The "externality" costs of pollution from agriculture are increasingly controversial, particularly where irrigators receive subsidized water. One measure of growing public concern over the environmental impacts of irrigation is the number of laws and regulations that pertain to irrigation. Federal and state responses to environmental concerns about agriculture, especially irri- gation, include efforts to control salinization and agricultural nonpoint sources of water pollution, water policies designed to protect instream flows and wetlands, and restrictions on the types and application of agricultural pesticides. Table 3.9 lists the federal programs related to water quality and agriculture. Most of these programs are obviously relevant to irrigated agriculture as well as to agriculture generally. The table does not include federal programs for species and habitat protection or other environmental issues relevant to agriculture. The committee cannot predict how the legislative pendulum will shift given the current, more conservative bent of Congress and emphasis on cost cutting, but its feeling is that while there will be some changes, the American people will not support a whole- sale retreat from environmental protection. Key environmental issues with direct association to irrigated agriculture are instream flows and wetlands, salinity and drainage, water quality, and anthropogenically induced climate change.

70 TABLE 3.9 Major Federal Programs Related to Water Quality and Agriculture A NEW ERA FOR IRRIGATION U.S. Department of Agriculture 1985 Food Security Act Provisions Conservation Reserve Program (CRP) provides annual rental payments to land owners and operators who voluntarily retire highly credible and other environmentally critical lands from production for 10 years. It also provides technical assistance and cost-sharing payments of up to 50 percent of the cost of establishing a soil-conserving cover on retired land. Over 30 million acres of cropland have been enrolled. Sodbuster provisions require that farmers who convert highly credible land to agricultural commodity production do so under an approved conservation system, or forfeit eligibility for USDA program benefits. Swampbuster provisions bar farmers who convert wetlands to agricultural commodity production from eligibility for USDA program benefits, unless USDA determines that conversion would have only a minimal effect on wetland hydrology and biology. Continuing Assistance Programs Agricultural Conservation Program (ACP) provides financial assistance through the Agricultural Stabilization and Conservation Service (ASCS) to farmers for implementing approved soil and water conservation and pollution abatement practices. Except for Water Quality Special Projects, conservation priorities are set by states and counties based on local soil and water quality problems. The program was initiated in 1936. ASCS also administers the Integrated Crop Management (ICM) program, a pilot ACP project to improve agrichemical management through cost-share assistance from crop advisory and soil testing services. The program was initiated in 1990. Conservation Technical Assistance (CTA) provides technical assistance by the Soil Conservation Service (SCS) through Conservation Districts to farmers for planning and implementing soil and water conservation and water quality improvement practices. The program was initiated in 1936. Small Watershed Program provides federal technical and financial help to local organizations for flood prevention, watershed protection, and water management. The program was initiated in 1954. Resource Conservation and Development Program assists multicounty areas to enhance conservation, water quality, wildlife habitat, recreation, and rural development. The program was initiated in 1962. Rural Clean Water Program is an experimental program implemented in 21 selected projects. It provides cost sharing and technical assistance to farmers voluntarily implementing best management practices to improve water quality. The program was initiated in 1980; it ends in 1995. Water Bank Program provides annual payments for preserving wetlands in important migratory waterfowl nesting, breeding, or feeding areas. The program was initiated in 1970. Environmental Protection Agency FIFRA Pesticide Programs The Federal Insecticide, Fungicide, and Rodenticide Act (FIFRA) gives EPA responsibilities for registering new pesticides and for reviewing and re-registering existing pesticides to ensure that, when used according to label directions, they will not present unreasonable risks to human health or the environment. Under FIFRA provisions, EPA may restrict or cancel use of any pesticide determined to be a potential hazard to human health or the environment. National Survey of Pesticides in Drinking Water Wells The National Survey tested for the presence and concentration of 127 commonly used agricultural chemicals in 1,350 statistically selected wells in all states. Water samples were analyzed and questionnaires filled out by well owners, operators, and local area experts on well construction locale and cropping and pesticide use patterns. Safe Drinking Water Act Programs The Safe Drinking Water Act (SDWA) requires EPA to publish maximum contaminant levels (MCLs) for any contaminants, including pesticides, that may have adverse health effects in public water systems

IRRIGATION TODAY 7 (those serving over 25 persons or with 15 connections). Standards established by EPA under the SDWA are also being used as guidelines to assess contamination of ground water in private wells. The EPA also sets nonregulatory health advisory levels on contaminants for which MCLs have not been established. Clean Water Act 1987 Water Quality Nonpoint Programs. Section 319 of the Clean Water Act requires states and territories to file assessment reports with EPA identifying navigable waters where water quality standards cannot be attained or maintained without reducing nonpoint-source pollution. States must also file management programs with EPA identifying steps that must be taken to reduce nonpoint pollution in those waters identified in the state assessment reports. The act authorizes up to $400 million total in federal funding for implementing the programs. To date, 43 states and territories have submitted nonpoint-source pollution assessments to EPA, and 36 have submitted final management programs. Clean Lakes Programs. Section 314 of the act requires states to submit assessment reports on the status and trends of lake water quality, including the nature and extent of pollution loading from point and nonpoint sources. Also, methods to control pollution and to protect/restore the quality of lakes impaired or threatened by pollution must be described. National Estuary Program. Section 320 of the act provides for identification of nationally significant estuaries threatened by pollution, preparation of conservation and management plans, and federal grants to prepare the plans. Twelve major estuaries have planning underway. Near Coastal Waters Strategy Through its Near Coastal Waters Strategy, EPA is integrating its water quality programs to target priority programs and prevent pollution in near coastal waters. This includes the implementation of nonpoint-source management programs in coastal counties and will, in several cases, encompass accelerated implementation of agricultural conservation programs. Regional Water Quality Programs The EPA and other federal agencies are cooperating on several regional programs to reduce nonpoint- source pollution, including the Chesapeake Bay Program, the Colorado River Salinity Control Program, the Great Lakes Program, the Gulf of Mexico Program, and the Land and Water 201 Program in the Tennessee Valley Region. U.S. Geological Survey National Water Quality Assessment Program Since 1986 the NAWQA program has conducted assessments of national and regional status of ground water resources and monitors trends in factors that can affect ground water quality. Agrichemical nonpoint-source contamination problems are under study in seven pilot projects. Regional Aquifer Systems Analysis Program The RASA program was established in 1978 to gather data on the quantity of water resources available in the nation's aquifers. RASA's objectives for each aquifer system study are to determine the availability and chemical quality of stored water and discharge-recharge characteristics, and to develop computer simulation models that may assist in understanding the ground water flow regime and changes brought about by human activities. Twenty-eight aquifer systems have been identified for study, fourteen of which have been completed. Federal-State Cooperative Program USGS supports local efforts to collect data on ground and surface waters through cost-sharing arrangements with state and local governments. For example, USGS has provided support for mapping state aquifers and for monitoring pesticide contamination problems and has assisted in developing wellhead protection programs. Source: Carlson et al., 1993.

72 A NEW ERA FOR IRRIGATION Instream Flows and Wetlands Problems related to instream flows and wetland ecosystems occur in every region of the country where significant quantities of surface and ground water are withdrawn for irrigation. Dams and diversions for surface supplies reduce instream flows, altering the natural hydrograph and affecting water temperature and flow regimes, trapping sediments, and changing water quality. In addition to obstruct- ing the passage of migratory fish, these changes degrade spawning and rearing habitats in the stream and riparian areas. The draining and filling of wetlands for irrigation have significant impacts on waterfowl and other aquatic species that use these habitats for nesting and breeding and also increase the potential for sedimentation and water pollution. In California, for example, construction of the Friant Unit of the Central Valley Project resulted in the dewatering of the San Joaquin River for a 50-mile reach below Friant Dam. As a result of dams and diversions for irrigation, water supplies available for fish and wildlife habitat have been greatly reduced. Ninety- two percent of the historic wetland acreage in the San Joaquin Valley has been converted to irrigated agriculture. (San Joaquin Valley Drainage Program, 1990~. In Idaho, ground water pumping by irrigators along the Big Lost River over the last 15 years has caused the dewatering of the lower reach of the river and lowered ground water levels precipitously (High Country News, 1995~. Large- scale irrigation projects constructed by the Bureau of Reclamation have drasti- cally altered habitat conditions in major river basins across the West, including the Platte River, the Colorado River, the Columbia River, and the Snake River.3 Many fish and other aquatic species that depend on habitat values in these rivers are listed as threatened or endangered under federal and/or state endangered species laws, although it must be noted that irrigation withdrawals are only one factor among many (e.g., hydroelectric power generation) that contribute to instream flow problems. Salinity and Drainage Salinity and drainage problems arise from natural hydrological and geochemi- cal factors the earth's rocks and soils contain mineral salts, which are released via normal chemical weathering processes. Irrigation in areas rich in such salts can concentrate the salts in water and soils (surface evaporation and transpiration by plants both act to move water into the atmosphere, leaving concentrated salts behind). The major dissolved mineral salts at issue are sodium, calcium, magne- sium, potassium, chorine, SO4, HCO3, CO3, and NO3. Over time, salts concen- trated in soils can hinder plant germination, seeding, and growth and undermine the yield and quality of plants. Saline drainage water can have adverse effects on water quality and, in turn, harm wildlife populations and make the water less desirable for other users.

IRRIGATION TODAY 73 About 30 percent of the land in the conterminous United States, much of it concentrated in the West, has a moderate to severe potential for salinity problems (Tanji, 1990~. The upper Colorado River basin, the northern Great Plains, and California's San Joaquin Valley are examples of areas that suffer salinity and drainage problems. The accumulation of salts in soils depends on the salinity of the applied waters, the salinity of the native soil, and the rate at which salts are leached out of the root zone. A related problem is waterlogging of the soil: waterlogging in the root zone depends on the drainage characteristics of the soil, whether there is a restricting layer in the soil, and the soil's capacity for deep percolation. In poor conditions, waterlogging can occur relatively rapidly. In good conditions, irrigation may be practiced for decades, and even centuries, before surface drainage problems arise. Irrigation-induced salinization can be avoided by providing adequate drainage, but drainage is expensive and exacts an environmental price as well it degrades water quality along its disposal route and in closed basins can render the terminus biologically uninhabitable (van Schilfgaarde, 1990~. Water Quality Surface return flows and drainage from irrigation are a leading source of water pollution in rivers, lakes, streams, and estuaries nationwide. According to recent estimates, irrigated cropland in the West accounts for 89 percent of qual- ity-impaired river mileage. Irrigated agriculture accounts for more than 40 per- cent of the pollution in lakes with impaired water quality (U.S. Environmental Protection Agency, 1992~. In the arid West, low river flows can exacerbate pollution problems from irrigation because surface runoff and drainage often provide a significant portion of these flows. Pollutants mobilized and transported by irrigation return flows and drainage include naturally occurring trace elements (e.g. selenium, boron, molybdenum), nitrogen, and salts, as well as pesticides, herbicides, and other chemicals (U.S. Fish and Wildlife Service, 1992~. Signifi- cantly, irrigation return flows are the most common source of pollution in na- tional wildlife refuges (U.S. Environmental Protection Agency, 1992~. While fewer data are available on the effects of agricultural drainage on species other than waterfowl, agricultural runoff is believed to affect adversely fish popula- tions in many river reaches in the country (U.S. Fish and Wildlife Service, 1992~. The trend toward a greater public policy focus on irrigation's impact on the environment is borne out by changes in various policies and institutions serving both irrigation and environmental goals. The mission of the Soil Conservation Service, now called the Natural Resources Conservation Service, has been modi- fied and expanded over the past 50 years. It has gone from helping farmers prevent soil erosion to conducting activities and providing technical and financial support to farmers to conserve highly credible and environmentally sensitive lands and protect water quality.4 In 1987 the Bureau of Reclamation, historically

74 A NEW ERA FOR IRRIGATION the supplier of one-fifth of all irrigation (agricultural) water in the United States and manager of 45 percent of the West's water, announced the end of its mission of helping to settle the West through the construction and operation of major dams and diversions, and the beginning of a mission focused on resource man- agement (Bureau of Reclamation, 1987~. In 1992, the Central Valley Project Improvement Act (P.L.102-575, Title XXXIV, 106 Stat.4706) set aside 800,000 acre-feet of water previously delivered by the federal Central Valley Project to agricultural users for fish and wildlife habitat.5 In addition, water users were required to pay surcharges on irrigation water to be used to finance environmen- tal restoration. In 1987, amendments to the Clean Water Act required states to assess the extent of nonpoint-source water quality impairment and to develop programs to manage nonpoint-source pollution. Section 319 of the act authorized $400 mil- lion in grants to states to assist in this effort (33 U.S.C. Section 1329~. In addition, nonpoint-sources must be factored into the calculations that allocated pollution reduction responsibilities among dischargers for each water body that does not meet water quality standards (section 303; U.S.C. Section 1313~. In 1990, amendments to the Coastal Zone Management Act, administered by the National Oceanic and Atmospheric Administration and the Environmental Pro- tection Agency, required states with coastal zone management programs to de- velop programs for the control of nonpoint sources, including agriculture (Coastal Zone Act Reauthorization Amendments, 1990~. Several states have adopted programs or passed legislation to protect aquatic habitats and the species that depend on them. Minimum instream flow require- ments, appropriations for instream rights, water transfer options, conservation easements, and other mechanisms are being employed to address problems con- cerning the quantity and quality of water available to fish and wildlife resources. In the turfgrass sector, soil erosion and runoff during construction and the potential for leaching and runoff of nutrients and pesticides from established sites can lead to impacts on fish and wildlife habitats and aquatic systems. These impacts likely will continue to fall under the urban stormwater provisions of the Clean Water Act and sometimes state legislation. Climate Change The Second Scientific Assessment of Climate Change by the Intergovern- mental Panel on Climate Change (IPCC) (1996) concludes for the first time that a global warming attributable to human activities is now evident in the historic record. Under a mid-range emission scenario, global mean surface temperature relative to 1990 is expected to increase by about 2°C by 2100, when the effects of greenhouse gas emissions and sulfate are considered. Although beyond the time horizon that is the focus of this study, if it occurs, greenhouse warming is certain to have a major impact on water supplies. A

IRRIGATION TODAY 75 warmer climate would accelerate the hydrologic cycle, increasing both the rates of precipitation and evapotranspiration. The regional impacts, however, are highly uncertain. Regional precipitation patterns, evapotranspiration rates, the timing and magnitude of runoff, and the frequency and intensity of storms would be affected. But the magnitude and sometimes even the direction of the changes for particular river basins and watersheds are uncertain. The range of likely changes in average annual precipitation associated with an equivalent doubling of atmospheric carbon dioxide for any given region might be on the order of plus or minus 50 percent (Schneider et al., 1990~. The hydrologic uncertainties are compounded because relatively small changes in precipitation and temperature can have sizable effects on the volume and timing of runoff, especially in arid and semiarid areas. For example, Nash and Gleick (1993) have speculated on the estimated impacts of alternative temperature and precipitation changes on annual runoff in several semiarid areas. In their sce- nario, with no change in precipitation, estimated runoff in these study areas declines by 3 to 12 percent with a 2°C increase in temperature and by 7 to 21 percent with a 4°C increase in temperature. A 10 percent increase in precipitation does not fully offset the negative impacts on runoff attributable to a 4°C increase in temperature in three of the five basins for which this climate scenario was studied. The CO2 fertilization effect will affect plant growth and possibly water sup- plies. Research results suggest that the increasing levels of atmospheric carbon dioxide (CO2) levels will increase the growth and yield of C3 plants (small grains, legumes, root crops, and most trees) by 34~+/-6) percent and C4 plants (e.g., maize and sorghum) by 14 (+/-11) percent (Rosenberg et al., 1990~. The impacts of the CO2 fertilization effect on water supplies is less certain because of two counteracting effects. On the one hand, an increase in leaf and root areas has the potential to increase transpiration and, thereby, reduce runoff. A simulation analysis suggests that a 15 percent increase in the leaf area index (other things being constant) would increase summertime evapotranspiration from a wheat field in Nebraska by 5 percent. On the other hand, a rise in atmospheric CO2 levels would increase stomata! resistance, the primary plant factor controlling evapotranspiration. Transpiration from a given leaf area declines as the stomata! resistance rises. In another simulation of the impacts of climate variables on the Nebraska wheat field, a 40 percent increase in stomata! resistance (other things being equal) reduces summertime evapotranspiration by 12 percent (Rosenberg et al., 1990~. In summary, the prospect of a global greenhouse warming introduces major new uncertainties and challenges for irrigators as well as for other farmers and water users. The allocation of water supplies among competing uses in response to any climate-induced shifts in hydrology and the response of irrigators to these changes is likely to be an important determinant of the future of irrigation.

76 A NEW ERA FOR IRRIGATION THE TURFGRASS SECTOR When precipitation is insufficient, turfgrass must be irrigated to provide the desired turf appearance and recuperative ability. Problems arise when there is an extended period of lack of precipitation or lack of availability of either ground water or surface water to allow for turf irrigation. The importance of turfgrass irrigation was most clearly realized during the drought period of 1976 to 1978 in the western United States, when extensive damage occurred. Although turf was commercially recognized before World War II, the rapid growth and development of the turf industry occurred after the war. In 1965 turfgrass was a $4.3 billion industry (Turfgrass Times, 1965~. By 1992 it had grown to a nearly $30 billion industry. The fixed asset value of turf is, of course, many times that annual expenditure. California, Florida, Michigan, New York, North Carolina, Pennsylvania, and South Carolina all have billion-dollar turf industries, and Illinois and Texas are very near this level. A survey of 2,309 golf courses in late 1984 by the Golf Course Superintendents Association of America (GCSAA) and the National Golf Foundation (NGF) provided statistical data on the acreage and cost of maintaining America's golf courses. Projecting the financial data obtained from the sample, it is estimated that $1.7 billion is spent each year for golf course maintenance and that the nation's courses had a mainte- nance equipment inventory valued at more than $1.8 billion (Prusa and Beditz, 1985~. Even though the technology of turfgrass management has undergone tremendous development, it is still labor intensive. It is estimated that 380,000 people make their living directly from the care and maintenance of turf in the United States. There are over 50 million home lawns and more than 14,000 golf courses in this country (Schroeder and Sprague, 1994~. Water use rates for turfgrass vary widely, from 0.1 inch per day for foggy coastal climates to 0.45 inch per day for dry desert areas (Beard, 1982~. A golf course may require a water source capable of supplying as much as 1.5 to 3.5 million gallons of water per week during the golf season (Jones and Rando, 1974~. Surface waters of all types are common direct sources of water for golf courses and other larger turfgrass areas. Frequently, small streams and major drainage channels may be dammed, excavated, or both, and the impounded water used to irrigate the golf course. Small reservoirs (less than 50 acre-feet in size) provide only 2 percent of the nation' s total storage capacity. However, they are a significant source of water for golf courses and park areas. Water harvesting and storage in small ponds and reservoirs are increasingly becoming a major element in golf course design. Treated effluent water, although not technically "surface water," is an alter- native source of supplemental irrigation water. Because of its nutrient content, it is a particularly valuable source of irrigation water for sod farms and golf courses. The quality of the effluent depends on the source; therefore, it varies widely.

IRRIGATION TODAY 77 Advantages and disadvantages are associated with use of effluent (Watson, 1978~. Effluent water or wastewater is used to irrigate several golf courses, including the Eisenhower Course at the Air Force Academy; Innisbrook at Tarpon Springs, Florida; Randolph Park at Tucson, Arizona; and some military courses. Develop- ment of multiple-plumbing systems to accommodate regular and effluent water for turf facilities is inevitable. Many golf courses already use such systems, and use of effluent water for golf course irrigation is mandatory in California where it is available (Thomas, 1994~. The availability of sufficient water of adequate quality and price in the future will pose a challenge to the turfgrass industry. In humid and subhumid areas, watering of home lawns often is restricted because municipal distributive sys- tems have not kept up with the rapid expansion of suburban areas. For the same reasons, watering of turfgrass areas may be restricted in semiarid and arid re- gions. Alternative water sources that may be useful to the turfgrass industries include wastewaters, including treated sewage effluents; capture and impound- ment of runoff waters; and dual water systems for turf facilities, including home lawns, to accommodate potable and nonpotable waters (Watson, 1985~. THE SPECIAL CASE OF INDIAN IRRIGATION The legal, historical, and political framework for Indian irrigation and natu- ral resource use is rooted firmly in the history and development of the United States. American Indians have a unique relationship with the United States which stems from the Constitution, Treaties, Executive Orders, Court decisions, and legislation enacted since the late eighteenth century through the present. The body of law created by these mechanisms establishes a framework for the imple- mentation of the U.S. trust responsibility for the protection of Indian natural resources. As the twenty-first century approaches, the increased implementation of these treaty rights through the development of water for agricultural or nonag- ricultural enterprises is central to Indian economic development activity. While much of the treaty making was completed more than a century ago, it is only now that many of the provisions of the treaties are coming to fruition. The securing of water supplies and other natural resources has implications for irri- gated agriculture in the United States, particularly in the Northwest, Southwest and Missouri River basin. Today, American Indians own 2.7 million acres of cropland, of which 64 percent is irrigated. The total estimated income from Indian irrigation, both in private systems and BIA-administered programs ex- ceeds $1 billion annually.6 The development of irrigated agriculture on Indian reservations and the forced transformation of Indian culture in the mid to late nineteenth century formed the core development vision of U.S. policy regarding American Indians. Reservations were set aside as homelands, whose purpose was envisioned as agricultural. Most tribal irrigation projects were authorized congressionally. Un

78 A NEW ERA FOR IRRIGATION der the general appropriations for irrigation authorized by Congress, the irriga- tion systems that were built for tribes were refinements of earlier irrigation sys- tems constructed by the tribes themselves prior to any assistance from the federal government (Bureau of Indian Affairs, 1975~. In several instances, existing non- Indian projects were extended to meet the needs of the Indians. While all of this work was designed to "fulfill treaty stipulations with various Tribes," many irrigation systems on Indian reservations were constructed, improved, or ex- tended by the federal government without consideration as to economic feasibil- ity and repayment capability, a fact that is common to all irrigation projects constructed with federal funds during this century. In many cases, such projects were constructed without the consent of the Indians involved. Table 3.10 presents a partial listing of the 71 statutorially authorized Indian irrigation projects. The Pick-Sloan program of the 1944 Flood Control Act also authorized the construction of Indian irrigation projects. To date, few Indian irrigation projects have been constructed under the Pick-Sloan program. It is significant to note that initial appropriations authorized were in most cases not sufficient to finish the project, nor to design the project for effective water deliv- ery. In addition, funding did not cover routine operation, maintenance, and replacement activities. Nearly all of these projects have serious replacement, operations, and maintenance costs and other problems that have inhibited full agricultural development and effective water delivery. There are also statutorily authorized power projects in conjunction with irrigation projects, which were established by Congress to provide power for pumping of water to supplement gravity-flow systems on reservation. These include Colorado River, Flathead, San Carlos, and the Wapato irrigation projects. In addition to these formally designated projects, approximately half of the irrigated cropland in Indian Country is irrigated by tribal individuals or tribal government operators. Many of these systems are private ditch systems which retain the essential character and disposition of the original design. Because of the lack of formal funding for the operation, maintenance, and repair of these systems, some private systems are in disrepair. Nevertheless, several Tribal operations, such as Gila River, Navajo, Yankton, Winnebago, Standing Rock, and Lower Brute have fully operating and sophisticated irrigation systems. During the course of development of irrigation in Indian Country, there has been considerable controversy over the construction, payment, and repayment of construction costs associated with Indian irrigation projects. The controversy has greatly affected the condition of Indian irrigation projects today. Beginning in 1914, 20 years after the Dawes Allotment Act,7 irrigation construction costs were deemed reimbursable to the federal government either by the Indians or non-Indian successors in interest. In 1921, these debts became a lien on the property. Because of the inability of Indians or their non-Indian successors to repay the government, many irrigation systems fell into disrepair and lands fell out of Indian ownership. Acts of Congress in 1928, 1933, and 1936 either

IRRIGATION TODAY TABLE 3.10 Partial list of Indian Irrigation Projects Authorized by Statue 79 Year Statute State Blackfeet Project 1907 34 Stat. 1035 Montana Coachella Valley 1950 64 Stat. 470 California Colorado River Reservation 1935 49 Stat. 240 Arizona/California Crow Indian Irrigation 1891 26 Stat. 1040 Montana Flathead Project 1904 33 Stat. 365 Montana Fort Hall Project 1894 28 Stat. 305 Indiana Fort Peck Project 1908 35 Stat. 558 Montana Middle Rio Grande Pueblos 1928 45 Stat. 383 New Mexico Navajo Project 1962 70 Stat. 96 New Mexico San Carlos Project 1924 43 Stat. 457 Arizona Soboba Project 1970 84 Stat. 1465 California Uintah Project 1906 34 Stat. 375 Utah Valve Vo Project 1965 79 Stat. 1071 Arizona Wapato Project 1904 33 Stat. 595 Washington Wind River 1905 33 Stat. 1016 Wyoming deferred payment of debts or canceled inappropriate debts or liens against Indian and non-Indian property. The inconsistency in funding has contributed to the current deteriorated condition of many Indian irrigation projects. The Bureau of Indian Affairs (BIA) currently has the primary management responsibility for Indian irrigation projects, although some tribes have contracted this authority from the BIA using provisions of the 1973 Indian Self Determina- tion and Education Assistance Act. BIA management of irrigation projects has been severely constrained by institutional problems, lack of funding, and the interplay between land laws, repayment requirements, and land ownership pat terns. A 1975 report to the Senate Committee on Interior and Insular Affairs on the status of construction of Indian irrigation projects documented the need for more than $200 million just to complete and rehabilitate the 71 Congressionally autho- rized Indian irrigation projects currently administered by the BIA (Report to the U.S. Senate Committee on Interior and Insular Affairs on the Construction of Indian Irrigation Porjects, 1975~. Estimates of the costs for OM&R on private systems are not readily available. OM&R needs on formal projects could repre- sent a substantial liability to the United States as trustee for Indian Tribes. As a result, policy decisions related to Indian irrigation projects and water resources may significantly affect water resources available to irrigated agriculture. NOTES 1. This section draws extensively on the following sources: U.S. Department of Commerce (1987), Bajwa et al. (1992), Solley, et al. (1993), Boggus et al. (1993), and Gollehon et al. (1994). 2. It should be noted that irrigation runoff is some cases is responsible for creating and maintain- ing wetland habitats, and curtailment of irrigation may on occasion actually harm or eliminate such wetlands. 3. Numerous studies by federal agencies document these impacts. See, for example, Bowman, David. 1994. Instream Flow Recommendations for Central Platte River, Nebraska. U.S. Fish and Wildlife Service, Denver, Colorado. May 23, 1994; U.S. Fish and Wildlife Service. Final Recovery Implementation Program for Endangered Fish Species in the Upper Colorado River Basin. Denver,

80 A NEW ERA FOR IRRIGATION Colorado., September 29, 1987; Department of Interior, Bureau of Reclamation. 1993. Operation of Glen Canyon Dam, Draft Environmental Impact Study. Washington, D.C. May; Northwest Power Planning Council. 1994. Columbia River Fish and Wildlife Program. Portland, Oregon, December; National Marine Fisheries Service, 1995. Proposed Recovery Program for Snake River Salmon, Washington, D.C., March. 4. In 1994 the USDA expenditures on conservation and related programs affecting agriculture were estimated as follows: Conservation Reserve Program, $3.5 billion; wetlands programs, $56 million; water quality programs, $212 million; and other conservation, $1.5 billion (USDA, Agricul- tural Resources and Environmental Indicators, 1994). 5. The Central Valley Project Improvement Act also includes requirements that water districts and individuals who use federally supplied water assume responsibility for control and management of drainage discharges in order to comply with federal and state water quality standards (Section 3405(c)). 6. Unpublished BIA preliminary estimates for 1994. 7. 25 USC 348. REFERENCES Bajwa, R. S., W. M. Crosswhite, J. E. Hostetler, and O. W. Wright. 1992. Agricultural Irrigation and Water Use, ERS/USDA (Agriculture Information Bulletin No. 638). Beard, J. B. 1982. Turf Management for Golf Courses. Minneapolis, Minn.: Burgess Publishing Co. Bird, J. W. 1987. Transferability of Indian water rights. J. Wat. Res. Plann. Mgt. 113. Boggess, W., R. D. Lacewell, and D. Zilberman. 1993. Economics of water use in agriculture. In Agricultural and Environmental Resource Economics. G. Carlson, J. Miranowsiki, and D. Zilber- man, eds. New York: Oxford University Press. Bryant, K., and R. D. Lacewell. 1988. Adoption of Sprinkler Irrigation on the Texas High Plains: 1958 to 1984. Texas Agricultural Experiment Station, Department of Agricultural Economics DIR 88-1, 5P-1. College Station, Tex. Bureau of Indian Affairs. 1975. Report to the United States Senate Committee on Interior and Insular Affairs on the Status of Construction of Indian Irrigation Projects. Bureau of Reclamation. 1987. Assessment '87: A New Direction for the Bureau of Reclamation. Washington, D.C.: Bureau of Reclamation. Carlson, G., D. Zilberman, and J. A. Miranowski. 1993. Agricultural and Environmental Resource Economics. New York: Oxford University Press. Casterline, G., A. Diner, and D. Zilberman. 1989. The adoptions of modern irrigation technologies in the United States. In Free Trade and Agricultural Diversification. A. Schmidt, ed. London: Westview Press. Coastal Zone Act Reauthorization Amendments. 1990. P.L. 101-508, Section 6201 et seq., 16 U.S.C. Section 1455b et seq. (1993 Supp.). Colby, B. G. 1994. The economics of Indian water conflicts: Competing property rights, shifting distributions of risk and the role of the market in policy implementation. In Water Quantity and Quality Disputes and their Resolution. A. Dinar and E. Loehman, eds. Praeger Publishers, Greenwood Publishing Inc. Council for Agricultural Science and Technology (CAST). 1988. Effective Use of Water in Irri- gated Agriculture. Report No. 113. Deason, J. P. 1982. The Federal Role and the Objectives of Indian Water Resources Development. Paper presented at the 1982 ASCE Specialty Conference, Water Resources Planning and Man- agement Division, Lincoln, Neb. Folk-Williams, J. 1985. What Indian Water Means to the West. Western Network, Santa Fe, N. Mex.

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