Conserving water resources: how the Farm Bill can improve

irrigation efficiency and get more water conservation for

the taxpayer buckFrank A. Ward

Professor of Water PolicyNM State University

Washington DCDirksen room 406

June 7, 2013

2

• Continued population and urban demand growth

• Shrinking key ecological assets• Irrigated ag consumes 85-90% of water in NM• Ongoing search for ways to conserve water in

irrigated agriculture• Climate Change: more floods/droughts, greater

conflict potential in dry places like NM– technology (drip, sprinkler, water saving crops)– policy (subsidies, regulations, pricing,

… )– Projects (infrastructure, leveling, … )

Background

3

Aim: Identify recent lessons learned about policies that can promote real water savings in

irrigated agriculture

Recent study: Analyzed irrigation waterconservation subsidies for their effect on water used in irrigation and on conserved water available for other uses.

4

Reducing irrigation water use

• Reduce land in production– Cities buy or rent water or water rights from ag– Farm prices deteriorate

• Alter crop mix, e.g.:– More acres in cotton– Fewer acres in alfalfa, pecan orchards– Develop more drought tolerant crop varieties

• Reduce water application rates (deficit irrigate)

• Shift to water conserving irrigation technology– To sprinklers– To drip irrigation

ReminderEvaporation v Transpiration

Irrigation / AcWeighted Ave over Crops (EBID)

5

Technology

Apply ET E? T? I. Eff

Surface 4.27 2.74 0.64

Drip 3.45 3.16 0.90

Separating E from TZ. Samani, NMSU, April 3, 2013

• No simple methods for separating E and T. His satellite ET map of EBID does not split E-T.

6

7

Gaps• Little work in NM (or elsewhere) explaining

what affects irrigation water savings that integrates– Farm economics: profitability

– Farm hydrology: water application

– Agronomy: yields by crop

– Basin hydrology: net water depletions

– Basin institutions: protect senior water rights

8

Aims• Data: Assemble data on crop water

applications, crop water use, yields, land in production, crop mix, cost, and prices that characterize economics of irrigated ag in NM’s RG Project Area

• Economic analysis: Analyze profitability, production, land and water use in the Area.

• Policy Analysis: Forecast the same for:– Several drip irrigation subsidies 2– Selected water supply scenarios 6

9

Study Region: Elephant Butte Irrigation District, NM

• http://www.ebid-nm.org/

10

Approach

• Analyze water conservation subsidies that reduces capital cost to convert from surface to drip. – Farm Income effect– Hydrologic effect on water app/depletion

• Integrates farm economics and basin hydrology

11

Farm Economics

• NM State U Farm costs and returns

• Published by NM county, year, crop, and irrigation technology

• Web -- http://aces.nmsu.edu/cropcosts/

Pecans, drip irrigated

12

Pecans, surface irrigated

13

Pecans: Drip or Surface Irrigated

14

15

Farm Water Economics 101

• Compare drip and surface irrigation– Drip: better applies quantity and timing of

water that the plant needs for max yields– Drip: higher yields higher ET, lower aquifer

recharge– Drip: reduces water applied– Drip: conversion costs are high

16

Cost of Converting:Surface to Drip Irrigation

• Conversion Capital Costs: – About $2500 / ac for 10 year life– About $365 / ac per year at 7% interest

• Conversion is a major investment, so for the conversion to increase income:– Yield gain must be high – or– $ Value of saved water must be high

• Maximizes Farm Income by choosing land in production, by – crop – irrigation technology

• Subject to Constraints– Hydrologic (gw, sw)– Agronomic: yields, including salinity– Economic: Pecan acreage– Institutional17

Quantitative Analysis of NM Ag Water Conservation

18

Crop Water Data Used, EBID, NM (Samani)

Crop Tech

A ET RYield

ton/acTech

A ET RYield

ton/acac-ft/ac/yr ac-ft/ac/yr

Alfalfa S 5.0 3.3 1.7 8.00 D 4.1 3.7 0.4 9.00

Cotton S 3.0 2.3 0.7 0.42 D 2.8 2.5 0.3 0.46

Lettuce S 2.5 1.5 1.0 11.88 D 1.9 1.7 0.2 13.83

Onions S 4.0 2.3 0.7 16.88 D 3.0 2.7 0.3 20.08

Green Chile S 3.0 2.0 1.0 11.00 D 2.7 2.4 0.3 13.25

Red Chile S 3.0 2.0 1.0 1.75 D 2.5 2.2 0.3 1.95

Pecans S 5.0 3.0 2.0 0.58 D 4.1 3.7 0.4 0.72

19

Under the Hood

20

Max Irrigation Income

[ * ]uckt ct uckt uckt ucktInc P Yield Cost L

(1 )

( . )

ucktt

u c k t u

IncNPV Income

r

u location

c crop

k irrig tech surface v drip

t year

• EBID land: about 90 K acres • EBID area water price and supply

– SW = 4 – 6” 2013– GW = $90 per af pumped 2013

• Salinity impacts on yields• Institutional

– Endangered Species Act– Rio Grande Compact– US Mexico Treaty of 1906– Rio Grande Project operation agreement

(NM/TX)

• Water Rights Protection– No increase in water depletions: NM OSE21

Constraints

22

Lessons Learned: water- conserving technology

• Irrigators invest in water-saving technologies when faced with lower costs for converting from surface to drip.

• Drip irrigation subsidies farm income, crop yields, value of food production, and crop water applications.

• By raising crop yields and raising crop water ET, drip irrigation subsidies put upward pressure on water depletions.

• Where water rights exist, authorities need to guard against depletions with growing subsidies that reduce water applications.

What promotes real water conservation in irrigation?

• Better water measurement– Gauges– Tracking use by crop (application, ET)

• Better water accounting– Current use patterns– Potential use patterns

• Adjudications– Who has the senior/junior rights in the face of

future supply variability. Important as drought/climate intensifies.

– Can promote trading water for $23

24

Draft Language in Farm Bill by Senator Udall

• Ensure that producers who get help to buy irrigation equipment do not use any of resulting water savings to bring more land under irrigation;

• Provide assistance to producers to make a transition to less water intensive crops or to dryland farming; and

• Authorize EQIP payments for practices that enhance and protect the flow of water in streams and rivers affected by irrigation.

• Ensure that producers who get help for irrigation equipment do not deplete more water from the river system than they did at some base period (FAW addition).

Thank you

http://agecon.nmsu.edu/fward/water