water in the west: current use and future challenges christopher goemans, ph.d. agricultural and...
TRANSCRIPT
Water in the West: Current Use and Future Challenges
Christopher Goemans, Ph.D.
Agricultural and Resource Economics
13th Annual Farmers Cooperatives ConferenceCooperatives, Agriculture & Water Resource Policies
Broomfield, CO
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Overview
• How is water currently “used”?• How is water currently allocated?• Future challenges• Options for dealing with future challenges
A story of change…
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Total Withdrawals
Figure 2, “Estimated Use of Water in the United States in 2005”, Circular 1344, USGS
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Total Irrigation Withdrawals
Figure 2, “Estimated Use of Water in the United States in 2005”, Circular 1344, USGS
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Colorado: Percent of Total Diversions by Activity
Public Supply; 6%
Irrigation; 90%
SS Industrial; 1%Other; 3%
Calculated based on 2005 USGS Water Use Estimates, water.usgs.gov/watuse/data/2005/
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Water Allocation Law in the U.S.
• Three “layers” of laws…
– Laws governing the allocation/use of water within states
– Laws governing the allocation/use of water across states
– Federal laws
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Within State Water Allocation
Two primary systems:
1. Riparian Law
2. Doctrine of Prior Appropriation
– Primarily in the Western U.S.
– Priority system of water rights based on: “first in time, first in right”
– Water Rights transferable as long as other water rights holders not “injured”
• Designed to protect existing uses/users
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Projected M&I and Self-supplied Industrial Gross Demand, 2000 - 2030
0
200,000
400,000
600,000
800,000
1,000,000
1,200,000
1,400,000
1,600,000
1,800,000
2,000,000
2000 2010 2020 2030
M&
I De
ma
nd
AF
/Yr
Year
West Slope
East Slope
Approximate Projected Increase in Demand:
•West Slope: >100,000 AF/Yr
•East Slope: >650,000 AF/Yr
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South Platte River Basin: Projected Population Growth by Region
7000000
6000000
5000000
4000000
3000000
2000000
1000000
0
1980 1990 2000 2010 2020 2030 2040 2050
Population Growth by Region
Northern Region
Central Region
Southern Region
%U %U
%U
%U
%U
%U
%U
%U
%U%U#
Denver
#
Boulder
The Basic Problem…
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tSupply tDemand
•In simple terms: Water managers goal is to make sure that there is enough supply to meet demand
•Questions: How much supply and where? How much demand will there be? Can we increase supply? Can we decrease demand?...
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Options for achieving this goal…
• Development of additional storage?• Reuse?• Conservation?• Reallocating water???
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A “Slice” of the Hydrologic Cycle
Consumptive Use: that part of water withdrawn that is evaporated, transpired by plants, incorporated into products or crops, consumed by humans or livestock, or otherwise removed from the immediate environment. (USGS)
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The Importance of Return Flows
The South Platte River Basin
• Annual total “native” flows: 1,400,000 acre feet
• Annual “trans-basin” inflows: 400,000 acre feet
• Annual surface water diversions: 4,000,000 acre feet
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Alternatives for Reallocating Water
Institutional Alternatives for Reallocating Water:• Water Rights Markets
Alternatives for freeing up the water:
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Why Water Transfers?
“It is commonly argued that reallocating just 10 percent of agricultural water to municipal uses
could boost municipal supplies by 50 percent West-wide.”
Water and Growth in Colorado- Nichols et al. (2001)
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Why Water Transfers?• “It is thus of increasing importance that existing water
supplies be allocated more efficiently than in the past. It is ludicrous that Southern California should incur a cost in excess of $450 per acre-foot for additional water while irrigators in the Central Valley continue to irrigate thousands of acres of crops which are in surplus nationally.” (Howe et al. 1986)
• “…the economic value of water is often several times that of agricultural use. For example, native irrigation water is worth $500 to $1,000 per acre-foot in the Northern District, while the asking price for municipal water from Windy Gap is 10 to 24 times more…” (Nichols et al. 2001)
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Alternatives for Reallocating Water
Institutional Alternatives for Reallocating Water:• Water Rights Markets
– “Buy and Dry”
Alternatives for freeing up the water:
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39,000 acres
2,600 acresor
2,400 acres
1,300 acresor
23,000 to 72,000 acres
7,900 to 16,000 acres
2,500 to 10,000 acres
No change
60,000 to 100,000 acres
133,000 to 226,000 acres
Potential Changes in Irrigated Acres
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Alternatives for Reallocating Water
Institutional Alternatives for Reallocating Water:• Water Rights Markets
– “Buy and Dry”
• Water Markets– Water Banks– Multi-year Leasing Agreements– Interruptible Water Supply Agreements
Alternatives for freeing up the water:• Rotational Fallowing• Limited Irrigation
Questions? Comments?
Christopher Goemans
Department of Agricultural and Resource Economics
Using Experimental Markets to Evaluate and Design Institutions
Example: Experiment Overview