Overview of the Colorado River Basin

Water Supply and Demand Study

GNEB Board Meeting

Teleconference / Webinar

March 22, 2012
Colorado River Basin Water Supply and

Demand Study

• Study Objective

- Assess future water supply and

demand imbalances over the next 50

years

- Develop and evaluate opportunities

for resolving imbalances

• Study being conducted by

Reclamation and the Basin

States, in collaboration with

stakeholders throughout the Basin

• A 2.5 year-Study beginning in

January 2010

• A planning study - will not result

in any decisions, but will provide

the technical foundation for future

activities
Historical Colorado River Water Supply & Use

(Annual)
50 Years of Colorado River Changes

1960 2010

Demographics / Land Use

• Population served 12 million 30 million

• Acres irrigated < 3 million 3 million

Physical System

• Storage capacity 30 maf 67 maf

• Hydropower generation capacity 6,700 GW 12,400 GW

Natural System

• Annual mean natural flow at L.F.

• Lowest 10-yr average flow at L.F.

15.1 maf (14.9)

12.5 maf

(1931-1940)

15.0 maf

12.0 maf

(2001-2010)

Institutions, Governance

• Legislation, Policies, Agreements • Colorado River Compact

• Boulder Canyon Project Act

• US-Mexico Water Treaty

• UC River Basin Compact

• CR Storage Project

• Decree in AZ v. CA

• NEPA

• ESA

• QSA

• 2007 Interim Guidelines
Study Phases and Tasks

Phase 1:

Water Supply

Assessment

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

Formulate

Approach to

Include

Uncertainty

Develop

Future

Supply and

Demand

Scenarios

Phase 2:

Water Demand

Assessment

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

Phase 3:

System Reliability

Analysis

3.1 - Identify

Reliability Metrics

3.2 - Estimate

Baseline System

Reliability

3.3 - Project Future

System Reliability

3.3.5-3.3.8 - Project

Future Reliability with

Opportunities

Phase 4:

Development &

Evaluation of

Opportunities

4.1 - Develop

Opportunities

4.2 -

Evaluate and Refine

Opportunities

4.3 -

Finalize Opportunities

Complete, described in Interim Report No. 1 and subsequent technical updates

Ongoing work since Interim Report No. 1

Kickoff in November 2011
Phase 1: Water Supply Assessment

Scenarios *:

• Observed Resampled

• Paleo Resampled

• Paleo Conditioned

• Downscaled GCM Projected

18

17 Meko et al.

16

15

14

13

12

11

10

775 975 1175 1375 1575 1775 1975

Year

* Multiple realizations for each scenario
Phase 2: Water Demand Assessment

Scenarios*:

• Current Projected: growth, development patterns, and institutions

continue along recent trends

• Slow Growth: low growth with emphasis on economic efficiency

• Rapid Growth: economic resurgence (population and energy) and

current preferences toward human and environmental values **

• Enhanced Environment: expanded environmental awareness and

stewardship with growing economy **

* Preliminary - Scenario names subject to change

** Additional “branches” possible depending upon assumed trajectory of specific socio-economic factors
Phase 3: System

Reliability Analysis

• Simulate the state of the

system on a monthly time

step over the next 50

years for each scenario,

with and without options

and strategies

• Metrics will be used to quantify

impacts to Basin resources

• Resource Categories

 Water Deliveries

 Electrical Power Resources

 Water Quality

 Flood Control

 Recreational Resources

 Ecological Resources
Phase 4: Development and Evaluation of

Opportunities to Balance Supply & Demand

• Consider a wide range of options and strategies

• Will not result in selection or funding of a proposed project

Projected Future Colorado River Basin Supply & Demand • Preliminary Assessment

based on:

- “Current Projected”

demand scenario

- supply scenario that

considers a changing

climate

• A broad range of

imbalances will be

considered when all

supply and demand

scenarios are combined
Summary of Options Submitted

• Over 140 options were submitted to the Study

• Multiple sub-categories exist, e.g. desalination, watershed management,

reuse, etc.

• Option will be posted on the Study website in late March

Increase

Supply

Reduce

Demand

Modify

Operations

Governance &

Implementation
Process for Developing & Evaluating

Options & Strategies
Milestones & Updated Study Timeline

February - January 2012 Quantify Demand Scenarios

December - March 2012 Perform “Baseline” System Reliability

Analysis

November - March 2012 Develop Options & Strategies

February - March 2012 Publish Technical Updates

March - April 2012 Perform System Reliability Analysis

with Options & Strategies

April - June 2012 Finalize & Evaluate Options &

Strategies

June 2012 Publish Draft Final Study Report

July 2012 Publish Final Study Report
Colorado River Basin Water Supply

and Demand Study

Study Contact Information

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

• Email: ColoradoRiverBasinStudy@usbr.gov

• Telephone: 702-293-8500; Fax: 702-293-8418