Colorado River Basin Water Supply and Demand Study Urban Water Institute 18 th Annual Water Policy Conference August 26, 2011.

Colorado River Basin Water Supply and Demand Study

Urban Water Institute18th Annual Water Policy ConferenceAugust 26, 2011

• Overview and Status of the Study

• Historical and Future Water Supply and Demand

• Next Steps

Colorado River Basin Water Supply and Demand Study

Historic Colorado River Water Supply & Use(Annual)

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•Study Objective– Assess future water supply and demand

imbalances and develop/evaluate opportunities for resolving imbalances

• Studied being conducted by Reclamation and the Basin States, in collaboration with stakeholders throughout the Basin

• Study began in January 2010 and will be completed by July 2012

• Email: [email protected]

• Website: http://www.usbr.gov/lc/region/

programs/crbstudy.html• A planning study – will not result in

any decisions

Colorado River Basin Water Supply and Demand Study

Study Outreach

Colorado River Basin Water Supply &

Demand Study

HydropowerWestern, CREDA. others Ecosystem

NGO collaborative.others

Endangered SpeciesFWS, others

OtherGeneral public, other

interested stakeholder groups

Native American Tribes and Communities

Lower Basin, Upper Basin

Water DeliveriesWater Districts (agriculture,

M&I use)

RecreationNPS, Concessionaires,

others

Options for Participation in the Study(not mutually exclusive)

• Monitor project website, webinars, emails• Review and comment on products• Receive periodic updates (formal and/or informal)• Establish points-of-contact with the “Study Team”

(Reclamation and the Basin States representatives)

• Participate in Study working groups (“Sub-Teams”)

• Other

Study Phases and Tasks

Phase 1:Water SupplyAssessment

Phase 2:Water Demand

Assessment

Phase 3:System Reliability

Analysis

Phase 4:Development & Evaluation of Opportunities

1.1 – Select Methods to

Estimate Current Supply

1.2 – Select Methods to Project

Future Supply

1.3 – Conduct Assessment of Current Supply

1.4 – Conduct Assessment of Future Supply

2.1 – Select Methods to Estimate Current

Demand

2.2 – Select Methods to Project Future

Demand

2.3 – Conduct Assessment of

Current Demand

2.4 – Conduct Assessment of Future Demand

3.1 – Identify Reliability Metrics

3.2 – Estimate Baseline System

Reliability

3.3 – Project Future System Reliability

4.1 – Develop Opportunities

4.2 – Evaluate and Refine

Opportunities

4.3 – Finalize Opportunities

3.3.5-3.3.8 – Project Future Reliability with

Opportunities

Formulate Approach to Include

Uncertainty

Develop Future

Supply and Demand

Scenarios

Green denotes essentially complete

• Metrics are measures that indicate the ability of the system to meet the needs of Basin resources

• Metrics will be used to quantify the impacts to Basin resources from future supply and demand imbalances

• Interim Report No. 1 includes metrics defined as of January 31, 2011

• Additional metrics are being considered– Flow-based indicator for ecosystem

health– Indicator to show unused but

allocated water, particularly for tribal water

System Reliability Metrics (Metrics)

Metrics Resource Categories

Depletions Electrical Power

Resources Water Quality Flood Control Recreational

Resources Ecological

Resources

Interim Report No. 1

• Interim reports provide a comprehensive “snapshot” of the Study’s progress to date

• Approach facilitates the integration of continuous technical developments and the ongoing input of stakeholders

• Interim Report No. 1 is a “snapshot” as of January 31, 2011 and is available at:

http://www.usbr.gov/lc/region/programs/crbstudy.html

• Submit comments by July 8, 2011• Further instructions available on website

Milestones & Updated Study TimelineFebruary – August 2011 Quantify Demand Scenarios

August – November 2011 Perform “Baseline” System Reliability Analysis

September – December 2011 Develop Options & Strategies

October 2011 Publish Interim Report No. 2

November 2011 – February 2012 Perform System Reliability Analysis with Options & Strategies

March 2012 Publish Interim Report No. 3

April – May 2012 Finalize & Evaluate Options & Strategies

June 2012 Publish Draft Final Study Report

July 2012 Publish Final Study Report

Historical and Future Water Supply and Demand

Historic Colorado River Water Supply & Use(10-year Running Average)

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Natural FlowColorado River at Lees Ferry Gaging Station, ArizonaWater Year 1906 to 2011

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1905 1910 1915 1920 1925 1930 1935 1940 1945 1950 1955 1960 1965 1970 1975 1980 1985 1990 1995 2000 2005 2010

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Water Year

Colorado River at Lees Ferry, AZ - Natural Flow

Average 10-yr Average

Provisional data, subject to change Estimated values for 2009-2011

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Estimated Natural Streamflow Volumes at Lees Ferry GageRunning 10-Year Averages from 771 - 2009

Meko et al (2007) Woodhouse et al (2006)Reclamation, Natural Flow (2009) Current 10-Year Average99 Percent Exceedance Volume

State of the System (Water Years 1999-20111)

109%

62% 59%

25%

52% 49%

104%

71% 70%

102%88%

73%

142%

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90%

100%

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End of Water Year

Unregulated Inflow into Lake PowellPowell-Mead Storage and Percent Capacity

Powell and Mead Storage (MAF) Unregulated Inflow into Powell (MAF) Powell and Mead Percent Capacity

1 Values for water year 2011 are projected. Unregulated inflow is based on the latest CBRFC forecast. Storage and percent capacity are based on the August 2011 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 based on the 30-year average from 1971 to 2000.

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Water Year Snowpack and Precipitationas of August 22, 2011

Colorado River Basin above Lake Powell

Water Year Precipitation

(year-to-date)

124%

Source: CBRFC

2011 Upper ColoradoObservedApr–Jul InflowPreliminary valuesas of August 16

Flaming Gorge – 162%

Blue Mesa – 124%

Navajo – 74%

Lake Powell – 163%

Colorado River Basin Storage (as of August 21, 2011)

Current Storage Percent Full MAF Elevation

(Feet)

Lake Powell 75% 18.17 3,658

Lake Mead 48% 12.55 1,112

Total System Storage* 66% 39.14 NA

*Total system storage was 33.97 maf or 57% this time last year

Lake Powell & Lake MeadOperational Diagrams and Current Conditions

8/21/11

1,112 12.55

8/21/11

8/21/11

3,658 18.17

8/21/11

Historical Consumptive Use and Loss1971-2008

Addressing an Uncertain Future

• The path of major influences on the Colorado River system is uncertain and can not be represented by a single view

• An infinite number of plausible futures exist

• A manageable and informative number of scenarios are being developed to explore the broad range of futures

(adapted from Timpe and Scheepers, 2003)

Water Supply Scenarios *

• Observed Resampled: hydroclimatic trends and variability are similar to the past 100 years

• Paleo Resampled: future hydroclimatic trends and variability are represented by reconstructions of streamflow for a much longer period in the past (nearly 1250 years) that show expanded variability

• Paleo-Conditioned: future hydrologic trends and variability are represented by a blend of the wet-dry states of the longer paleo-reconstructed period (nearly 1250 years), but magnitudes are more similar to the observed period (about 100 years)

• Downscaled GCM Projected: future climate will continue to warm with regional precipitation and temperature trends represented through an ensemble of future downscaled GCM projections

* Preliminary – Subject to change

102 Traces 1244 Traces 1000 Traces 112 TracesObserved Mean = 15002 Direct Paleo Mean = 14675 Paleo Conditioned Mean= 14937 Climate Projections Mean = 13588

8,000

10,000

12,000

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20,000

8,000

10,000

12,000

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18,000

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Projections of Natural Flow at Lees Ferry

2011 – 2060 Period Mean Annual Flows

Box represents 25th – 75th percentile, whiskers represent min and max, and triangle represents mean of all traces

Preliminary

1988 – 2007 period mean

Water Demand Scenarios *

• Current Trends: growth, development patterns, and institutions continue along recent trends

• Economic Slowdown: low growth with emphasis on economic efficiency

• Expansive Growth: economic resurgence (population and energy) and current preferences toward human and environmental values **

• Enhanced Environment and Healthy Economy: expanded environmental awareness and stewardship with growing economy **

* Preliminary – Subject to change** Additional “branches” possible depending upon assumed trajectory of specific socio-economic factors

Study Phases and Tasks

Phase 1:Water SupplyAssessment

Phase 2:Water Demand

Assessment

Phase 3:System Reliability

Analysis

Phase 4:Development & Evaluation of Opportunities

1.1 – Select Methods to

Estimate Current Supply

1.2 – Select Methods to Project

Future Supply

1.3 – Conduct Assessment of Current Supply

1.4 – Conduct Assessment of Future Supply

2.1 – Select Methods to Estimate Current

Demand

2.2 – Select Methods to Project Future

Demand

2.3 – Conduct Assessment of

Current Demand

2.4 – Conduct Assessment of Future Demand

3.1 – Identify Reliability Metrics

3.2 – Estimate Baseline System

Reliability

3.3 – Project Future System Reliability

4.1 – Develop Opportunities

4.2 – Evaluate and Refine

Opportunities

4.3 – Finalize Opportunities

3.3.5-3.3.8 – Project Future Reliability with

Opportunities

Formulate Approach to Include

Uncertainty

Develop Future

Supply and Demand

Scenarios

Yellow denotes current and future steps

Milestones & Updated Study TimelineFebruary – August 2011 Quantify Demand Scenarios

August – November 2011 Perform “Baseline” System Reliability Analysis

September – December 2011 Develop Options & Strategies

October 2011 Publish Interim Report No. 2

November 2011 – February 2012 Perform System Reliability Analysis with Options & Strategies

March 2012 Publish Interim Report No. 3

April – May 2012 Finalize & Evaluate Options & Strategies

June 2012 Publish Draft Final Study Report

July 2012 Publish Final Study Report

Study Contact Information• Website: http://www.usbr.gov/lc/region/programs/crbstudy.html• Email: [email protected]• Telephone: 702-293-8500; Fax: 702-293-8148

Colorado River Basin Water Supply and Demand Study