Colorado River Basin Water Supply and Demand Study NIDIS update February 24, 2011 Boulder, CO.

Colorado River BasinWater Supply and Demand Study

NIDIS updateFebruary 24, 2011Boulder, CO

Colorado River Basin Water Supply and Demand Study

• Two-year, $2 million study cost shared by Reclamation and the Basin States• Assess future water supply and demand imbalance• Assess risks to all basin resources• Investigate options and strategies to mitigate impacts

• A transparent, collaborative study with input from all stakeholders

• Email:[email protected]• Website:http://www.usbr.gov/lc/region/programs/ crbstudy.html

•Study Area– Colorado River Basin and those

adjacent areas of the Basin States that receive Colorado River water

•Cost-Share Partners– Arizona Department of Water Resources– (California) Six Agency Committee– Colorado Water Conservation Boar– New Mexico Interstate Stream

Commission– Southern Nevada Water Authority– Utah Division of Water Resources– Wyoming State Engineer’s Office– Reclamation (LC and UC Regions)

Colorado River Basin Water Supply and Demand Study

Annual Colorado River Water Supply & Use

Study Outreach

Colorado River Basin Water Supply &

Demand Study

HydropowerWestern, CREDA. others Ecosystem Demands

NGO collaborative.others

Endangered SpeciesFWS, others

OtherGeneral public, other

interested stakeholder groups

Native American Tribes and Communities

Lower Basin, Upper Basin

Water DeliveriesWater Purveyors (agriculture,

M&I use)

RecreationNPS, Concessionaires,

others

Study Phases and Tasks

Phase 1:Water Supply

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

Draft Water Supply Storyline Themes

• Observed (O)– Theme: Historic instrumental period for streamflow represents suitable

trends and variability for characterizing the future• Direct Paleo (DP)

– Theme: Paleoclimate period offers a more expansive understanding of streamflow variability that may be more representative of future variability

• Paleo Conditioned (PC)– Theme: Inter-annual variability of paleo reconstructions is believed to be

more representative of future variability, but streamflow magnitudes are believed to best represented by the instrumental period

• Climate Projection (CP)– Theme: Future climate and streamflow variability is represented through

global climate models and simulated hydrologic conditions driven by the results of these models

Global ClimateModels

Methodology for Incorporating Climate Projections in Future Supply

Emission Scenarios

(3 scenarios: A2, A1b, B1)

Bias Correction & Spatial Downscaling

(112 downscaled projections)

Hydrologic Modeling

(112 downscaled projections)

Systems Modeling

(112 traces)

16 GCMs

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

14,000

16,000

18,000

20,000

8,000

10,000

12,000

14,000

16,000

18,000

20,000

8,000

10,000

12,000

14,000

16,000

18,000

20,000

8,000

10,000

12,000

14,000

16,000

18,000

20,000

Current “Best” Estimate Natural Flow Conditions 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

DRAFT – SUBJECT TO CHANGE

1988 – 2007 period mean

Draft Demand Storyline Themes

• “A”: Current Trends– Theme: Growth, development patterns, and institutions continue along

recent trends

• “B”: Economic Slowdown – Theme: Low growth with emphasis on economic efficiency

• “C”: Expansive Growth – Theme: Economic resurgence driven by population growth and energy

needs• C1 branch to slower technology adoption• C2 branch to rapid technology adoption and slight increase in social values

• “D”: Enhanced Environment and Healthy Economy – Theme: Expanded environmental awareness and stewardship with

growing economy• D1 branch to current growth trends• D2 branch to higher growth and technology

Integration of Supply and Demand Scenarios

Recent Trends

Supply Scenarios(multiple realizations for each scenario)

Demand Scenarios

Current Trends

PR

C

A

B

D

O

PC

CP

Climate indexing for demands

Colorado River Simulation System (CRSS)

• Comprehensive model of the Colorado River Basin

• Developed by Reclamation (early 1970s) and implemented in RiverWareTM (1996)

• Primary tool for analyzing future river and reservoir conditions in planning context (NEPA EIS)

• A projection model, not a predictive model• Excellent for comparative analysis• Gives a range of potential future system

conditions (e.g., reservoir elevations, releases, energy generation)

• Simulates on a monthly timestep over decades

• Operating policy is represented by “rules” that drive the simulation and mimic how the system operates

• 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

System Reliability Metrics

Metrics Resource Categories

Depletions Electrical Power

Resources Water Quality Flood Control Recreational

Resources Ecological

Resources

Study Phases and Tasks

Phase 1:Water Supply

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

Colorado River BasinWater Supply and Demand Study

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

NIDIS updateFebruary 24, 2011Boulder, CO

Extra Slides

Demographics & Land Use

Economics & Technology

Soci

al &

Insti

tutio

nal

D2

A

D1

C1B

C2

Graphical Depiction of Driving Forces Categories and Scenarios

Today

Categorization and Selected Driving Forces for Storyline Development

General Driving Force Category

Key CRBS Driving Forces Identified in Survey

Natural Systems (Hydroclimate)

Changes in streamflow variability and trends [1] Changes in climate variability and trends (e.g. temperature,

precipitation, etc.) [2]Demographics & Land Use

Changes in population and distribution [4] Changes in agricultural land use (e.g. irrigated agricultural areas,

crop mixes, etc.) [5]Technology & Economics Changes in agricultural water use efficiency [8]

Changes in municipal and industrial water use efficiency [9] Changes in water needs for energy generation (e.g. solar, oil shale,

thermal, nuclear, etc.) [12]Social & Governance Changes in institutional and regulatory conditions (e.g. laws,

regulations, etc.) [10] Changes in flow-dependent ecosystem needs for ESA-listed

species [13] Changes in other flow-dependent ecosystem needs [14] Changes in social values affecting water use [15] Changes in water availability due to tribal water use and

settlement of tribal water rights claims [17]