Agricultural Water Use, Misuse, and Abuse: Facts and Fantasy

1. Agricultural Water Use, Misuse, and Abuse: Facts and Fantasy Noel Gollehon Natural Resources Conservation Service, USDA Presentation for the Horinko Group December 1, 2011 Washington, DC

2. Disclaimer Thoughts and opinions presented today are those of the author and do not represent those of USDA or the Natural Resources Conservation Service.

3. Distribution of Earth’s water, by source

4. Goals of presentation • Provide a National perspective water demands from irrigated agriculture • Acres • Water use • Crops • Focus on one driver of water use – Biofuel feedstock production • The scale challenge • Conclusions

5. U.S. irrigated acres & water applications Water Applied Irrigated Acres Source: NRCS, based Census of Agriculture Data and Farm and Ranch Irrigation Survey Data

6. Irrigation overview: Acres location, 2007 Source: USDA, 2007 Census of Agriculture

7. U.S. Irrigated acres, leading states Source: USDA, NRCS, based Census of Agriculture Data

8. Total and agricultural water withdrawals (1960-2005) and consumptive use estimates (1960-1995) 37% 84% 60 70 80 90 00 60 70 80 90 Consumptive Use* Withdrawals Source: USDA, NRCS, based on Kenny, et al, 2009 * Data limitations do not allow estimation of consumptive use in 2000.

9. U.S. Irrigation water withdrawals, 2005 Acre-feet (1,000) Nation: 60% Surface 40% Ground Source: NRCS analysis of USGS Water Use data

10. What is all that irrigation water used for?

11. U.S. irrigated acreage, 2007 Cropland irrigated (%) Acres (1,000) Irrigated acres Percent cropland irrigated Source: NRCS analysis of Census of Agriculture Data

12. U.S. irrigated crops, 1969 - 2007 Percent of 2007 irrigated area 23% 7% 9% 14% 21% 13% 13% Source: NRCS analysis of Census of Agriculture Data

13. Corn & Wheat Yields, Irrigated & Non-irrigated

14. Corn Cotton Soybeans Other Grains Hay Orchards & vegetables Other crops Regional irrigated cropping patterns, 2007 Source: NRCS analysis of Census of Agriculture Data

15. How much water is applied for irrigation?

16. How much water for an “average” corn field? • 130 acre center-pivot field • 12 inch application in 2008(reduction from 14 in 2003) • 42,357,120 gallons applied per year per field (27,152 * 12 * 130) • States with >100,000 acres range from 21 to 85 million gallons per field • 1,800 gallons /bu (based on average irrigated corn yield in 2008 of 181 bu/acre) Source: USDA, NASS, Farm and Ranch Irrigation Survey

17. 500-1,000 1,001-2,000 2,001-3,000 3,001-4,000 4,001-6,000 No data Gallons of irrigation water per bushel of irrigated corn, 2008 Source: NRCS based on Farm and Ranch Irrigation Survey Data

18. Average irrigation water applications levels for selected crops, U.S., 2008 Source: ERS based on 2003 Farm and Ranch Irrigation Survey data.

19. Summary of irrigation overview Irrigated agriculture is the 800 pound gorilla in the water use world Withdrawals: Major (but slowly declining) Consumptive use: Dominant sector Irrigation is a national production practice Surface water in the West is very important from a quantity view Per acre application levels are highly variable by crop and location Per field quantities are shocking large in the volume of water applied

20. A driver – Biofuel Feedstock Production

21. The Ethanol “Experiment” from 2002 to 2007 Corn acres 26% Irrigated corn acres 36% Corn production 48% Corn exports 53% Corn ethanol use 275% Corn price 81% 2002-2007 Source: NRCS, based on Census of Agriculture and ERS data

22. Irrigated corn share and current ethanol plant locations

23. Gallons of irrigation water per gallon of corn-based ethanol, 2008 185-370 371-740 741-1,110 1,111-1,480 1,481-2,222 No data Assuming all feedstock irrigated converting at 2.7 gallons per bushel. Source: NRCS based on Farm and Ranch Irrigation Survey Data

24. Regional crop shifts from 2002 to 2007, selected irrigated crops Pacific Mountain Southern Plains Northern Plains East Central Eastern Source: NRCS, based on Census of Agriculture data

25. Crop irrigation water applications by region Source: NRCS analysis of RFS, FRIS, and USGS water use data

26. High Plains Aquifer remaining and current & planned ethanol plant locations Source: NRCS based on 1999 USGS Digital map data and 2010 Renewable Fuels Association data.

27. The Ethanol “Experiment” Continues Corn acres 26% 20% Irrigated corn acres 36% ?? Corn production 48% 45% Corn exports 53% 25%* Corn ethanol use 275% 400%** Corn price 81% 130%# 2002-2007 2002-2010 * 2009 data ** Projected # Percentage based on corn at $5.40 per bushel, current price is $7.54 per bushel Source: NRCS, based on Census of Agriculture and ERS data

28. Summary of Biofuel Feedstock In the short run, increased agricultural production for biofuels will not alter the national view of water use Growing crops for next generation of biofuel production could have a more significant regional and local impact In some cases an increase in water use In other cases a decrease, depending on the crops being grown now and the biofuel crops produced In some cases an impact on groundwater by driving demand for irrigation water

29. The scale challenge and irrigation: Farm View

30. U.S. irrigated acres & water applications Water Applied Irrigated Acres Source: NRCS, based Census of Agriculture Data and Farm and Ranch Irrigation Survey Data

31. How was reduction in applied water accomplished? • Location, Location, Location • Reduced acres in higher application areas (Southwest) • Increased acres in lower application areas (Southeast & Northern Plains) • Improved, more efficient management and technology • Environmental Externalities • Irrigation Externalities

32. Change in U.S. Irrigated Acres location, 69-07 Source: NRCS based on 1969 and 2007 Census of Agriculture data

33. Changing Irrigation Application Technology 2008 1979 All Gravity Systems High-pressure Center Pivot Sprinklers Low-pressure Center Pivot Sprinklers Other Sprinklers Drip,Trickle, Micro Irrigation Source: USDA based on Farm and Ranch Irrigation Survey Data

34. Impact of Improved Efficiency

35. Impact of Improved Efficiency

36. Impact of Improved Efficiency

37. Impact of Improved Efficiency

38. Irrigation Efficiency (IE)

39. Improved Efficiency: Farm View • Improved accomplishment of target irrigation • The infiltration depth for a low-pressure, under-canopy, center pivot (or subsurface drip) approaches the target irrigation level • Decline in the area of field with over & under irrigation • Increase in yield • Increase in water consumed by crop ET because improved uniformity decreases over/under irrigation and water stress • Reduction in deep percolation with impact on return flows and groundwater recharge • Increased water use and reduced deep percolation have created environmental & irrigation externalities because • Institutions operate on water withdrawals (also termed diversions or water duty or allocation) • Hydrologic system operates on consumptive use

40. Improved Efficiency: Farm View • Why improve on-farm efficiency? • Save energy! • Improve farm profitability. • Potentially improve water quality. • Potentially increase commodity production. • Indirect land effect by decreasing pressure on marginal lands • Necessary for improved water management • Requires management improvement too • Save water when: • Return flow goes to sink or are non-recoverable • Withdrawals are from fossil water such that aquifer life is extended (not really saved water but extended aquifer life).

41. Acres impacted with improved water management and application technology practices from USDA’s Environmental Quality Incentives Program (EQIP) Over the last decade 2007 total irrigated acres 23% Cumulative Annual Source: USDA, NRCS, based EQIP data

42. The scale challenge and irrigation: Basin View

43. Base system IE = 50% Flow Amount 10 Diversion 8 On-Farm Beneficial Use 4 2 Return Flow 4 6 Flow Direction Basin Hydrologic View of Improved Irrigation Efficiency Escape 0

44. Basin Hydrologic View of Improved Irrigation Efficiency – Three systems involved Base system IE = 50% Institutional Response Flow Amount 10 Diversion 8 Hydrologic Response On-Farm Beneficial Use 4 2 Irrigator Response Return Flow 4 6 Flow Direction

45. Base system IE = 50% Flow Amount 10 Diversion 8 On-Farm Beneficial Use 4 2 Return Flow 4 6 Flow Direction Basin Hydrologic View of Improved Irrigation Efficiency: A Possible Outcome Improved system IE = 60% Flow Amount 10 Diversion 8 On-Farm Beneficial Use 4.8 2 Return Flow 3.2 5.2 Flow Direction

46. Base system IE = 50% Flow Amount 10 Diversion 8 On-Farm Beneficial Use 4 2 Return Flow 4 6 Flow Direction Basin Hydrologic View of Improved Irrigation Efficiency: A Possible Outcome Improved system IE = 60% Flow Amount 10 Diversion 8 On-Farm Beneficial Use 4.8 2 Return Flow 3.2 5.2 Flow Direction

47. Improved efficiency: Basin View • Improved efficiency does not assure an increase in downstream flow • Carefully define the goal • Motivation to reduce withdrawals depends on the water source and institutional circumstance • Reducing hydrologic water use (ET) usually reduces production • NRCS programs move toward “conservation goals” of increased stream flow and reduced aquifer use but must balance producer returns and the institutional framework (water law & contract requirements).

48. Examples of “improved” irrigation activities

49. Furrow Irrigation – Poorly managed advance

50. Furrow Irrigation – Poorly managed tailwater