Drought on the Colorado River
System: Impacts and Response
Bill Steele
Area Manager, Southern California Area Office
Urban Water Institute Annual Water Conference in San Diego, CA
August 25, 2016
Topics
• Colorado River Basin
Overview
• Lower Colorado River Water
Master Role
• Drought and Drought
Impacts
• Drought Response Activities
• Summary
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Overview of the
Colorado River Basin
• 16.5 million acre-feet (maf)
allocated annually
• 13 to 14.5 maf of
consumptive use annually
• 60 maf of storage
• 14.8 maf average annual
“natural” inflow into Lake
Powell over past 110 years
• Inflows are highly variable
year-to-year
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Natural Flow
Colorado River at Lees Ferry Gaging Station, Arizona
Water Year 1906 to 2016
Colorado River at Lees Ferry, AZ - Natural Flow
30
30
Annual Flow (MAF)
Average
25
25
20
20
15
15
10
10
5
5
0
0
Provisional data, subject to change
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10-yr Average
Water Year
Estimated values for 2013-2016
Lower Colorado River Water Master Role
• Boulder Canyon Project Act of 1928
established the Secretary of the
Interior as Water Master of the Lower
Colorado River
• Develop Annual Operating Plan for
Colorado River Reservoirs
• Administer water contracts
• Approve U.S. water orders
• Schedule water releases from Hoover,
Davis, and Parker Dams
• Account for all water use
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Lower Colorado River
Management Objectives
• Provide flood control and river
regulation
• Meet water orders
• Generate hydropower
• Implement LCR Multi-Species
Conservation Program
• Support recreational
opportunities
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State of the System (Water Years 1999-2016)1,2
50
100%
45
90%
40
80%
35
70%
30
60%
25
50%
20
40%
15
30%
147%
118%
118%
112%
80% 81%
5
64% 65%
94%
96% 94% 90%
78%
45% 47%
24%
2016
2015
2014
2013
2012
2011
2010
2009
2008
2007
2006
2005
2004
0%
2003
2001
2000
1999
0
20%
10%
57% 55%
2002
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Percent Capacity
Volume in MAF
Unregulated Inflow into Lake Powell
Powell-Mead Storage and Percent Capacity
End of Water Year
Powell and Mead Storage (MAF)
Unregulated Inflow into Powell (MAF)
Powell and Mead Percent Capacity
1Values
for Water Year 2016 are projected. Unregulated inflow is based on the latest CBRFC forecast dated August 1, 2016. Storage and percent capacity
are based on the July 2016 24-Month Study.
2 Percentages
at the top of the light blue bars represent percent of average unregulated inflow into Lake Powell for a given water year. The percent of
average is based on the period of record from 1981-2010.
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Lake Mead End of Month Elevation
1,225
Spillway Crest 1221 ft
1,200
1,175
September 1999
95% of Capacity
Elevation (ft)
1,150
1,125
1,100
1,075
July 2016 36% of
capacity
1,050
Prior to 1999, Lake Mead was last at elevation 1,072.75 feet in May 1937
In July 2016, Lake Mead was at its lowest elevation of 1,071.61 feet since it was first filled in the 1930s.
1,025
During the 1950s drought, Mead reached a low of 1,083.23 feet in April 1956.
January 1937 - July 2016
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2015
2012
2009
2006
2003
2000
1997
1994
1991
1988
1985
1982
1979
1976
1973
1970
1967
1964
1961
1958
1955
1952
1949
1946
1943
1940
1937
1,000
Drought Response
Activities
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Lake Mead – Key Elevations1,2
27.6 maf
1,229 ft
Flood Control or Surplus Conditions
)
1,145 ft
17.1 maf
Normal or ICS Surplus Conditions
1,074 ft*
1,075 ft
9.6 maf
Level 1 Shortage Conditions
1,050 ft
1,025 ft
1,000 ft
Not to scale
1 U.S.
10
895 ft
U.S. Lower Basin Shortage = 333 kaf
Mexico Reduction = 50 kaf
Level 2 Shortage Conditions
U.S. Lower Basin Shortage = 417 kaf
Mexico Reduction = 70 kaf
Level 3 Shortage Conditions
U.S. Lower Basin Shortage = 500 kaf
Mexico Reduction = 125 kaf
Dead Pool Storage 2.5 maf
Lower Basin shortage volumes based on the 2007 Interim
Guidelines (in place 2007-2026).
2 Mexico reductions based on Minute 319 (in place 2013-2017).
9.5 maf*
36% of Live
Capacity
7.7 maf
6.0 maf
4.5 maf
0.0 maf Dead Pool
*As of August 10, 2016
Lower Basin Surplus & Shortage through 2026
Percent of Traces with Lower Basin Surplus or Shortage
Projections from the April 2016 CRSS/MTOM Run1,2
100%
90%
80%
70%
60%
50%
40%
30%
20%
10%
0%
2017
2018
2019
2020
2021
Shortage of Any Amount
1
2023
2024
2025
2026
Surplus of Any Amount
The projections for 2017 are based on 30 simulations of December 31, 2016 conditions from the Mid-term Probabilistic Operations Model (MTOM).
For the period from 2018-2026, each of the 30 projected initial conditions from MTOM were coupled with 107 hydrologic inflow sequences,
based on resampling of the observed natural flow record from 1906-2012,
for a total of 3,210 traces analyzed in the Colorado River Simulation System
(CRSS).
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11
2022
Drought Response Activities
Basin-wide Pilot System Conservation Program
• Funders:
Reclamation, CAWCD, SNWA, MWD, and Denver Water
• Initial phase provided $11 million for voluntary pilot projects
that create system water
• System conservation agreements were implemented in both
basins
• Approximately 65 kaf of water will be conserved under the
initial phase of the program
• The program has been extended in 2016
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Drought Response Activities
Lower Basin MOU for Pilot Drought Response Actions
• Participants:
CAWCD, MWD, SNWA, Lower Basin States, and Reclamation
• 2014-2017 Goal:
Generate 740,000 acre-feet of water to benefit Lake Mead
elevation
• 2014-2019 Goal:
Generate 1.5 to 3.0 maf of water to benefit Lake Mead
elevation
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Projected Future Colorado River Basin
Water Supply and Demand
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Summary
• The Colorado River Basin is
experiencing an unprecedented
drought
• The chance of reaching critical
reservoir elevations at Lake
Mead continues to increase
• Safeguarding our shared water
supply is critical to all of us
• Cooperation and collaboration
will be the key to finding
sustainable solutions and
addressing current and future
challenges
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For further information:
www.usbr.gov/lc/riverops.html
[email protected]
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