1. CWAG 2010 WATER LAW CONFERENCE The Broadmoor Colorado Springs, Colorado April 29 – 30, 2010

2. Colorado River Reservoir Operations Terry Fulp Bureau of Reclamation, Lower Colorado Region CWAG Water Law Conference April 30, 2010

3. Colorado River Basin Operation governed by the Law of the River including: –Colorado River Compact (1922) –Boulder Canyon Project Act (1928) –U.S. Mexican Water Treaty (1944) –Colorado River Storage Project (1956) –Supreme Court Consolidated Decree (1964 and following) –Colorado River Basin Project Act (1968) Variable hydrology 60 million acre-feet of storage capacity System operated on a tight margin

4. Natural Flow Colorado River at Lees Ferry Gaging Station, Arizona Water Year 1906 to 2009

5. Annual Natural Flow at Lees Ferry Tree-ring Reconstruction (Meko et al., 2007) 25-Year Running Mean

6. Water Budget at Lake Mead Given basic apportionments in the Lower Basin, the allotment to Mexico, and an 8.23 maf release from Lake Powell, Lake Mead storage declines Inflow = 9.0 maf (release from Powell + side inflows) Outflow = - 9.6 maf (AZ, CA, NV, and Mexico delivery + downstream regulation and gains/losses) Mead evaporation loss = - 0.6 maf Balance= - 1.2 maf Data based on long-term averages

7. Colorado River Basin Storage (as of April 25, 2010) Current Storage Percent Full MAF Elevation (Feet) Lake Powell57%13.743,620 Lake Mead44%11.371,099 Total System Storage* 55%32.78NA *Total system storage was 31.88 maf or 54% this time last year

8. 2010 Upper Colorado Projected Apr–Jul Inflow as of April 15, 2010 Flaming Gorge – 45% Blue Mesa – 74% Navajo – 81% Lake Powell – 66%

9. State of the System (1999-2010) WY Unregulated inflow into Powell % of Average Powell and Mead Storage maf Powell and Mead % Capacity 199910947.5995 20006243.3886 20015939.0178 20022531.5663 20035227.7355 20044923.1146 200510427.1654 20067125.8051 20077024.4349 200810226.5253 20098826.4053 2010*6824.7849 * Inflow based on latest CBRFC forecast; storage and percent capacity based on April 2010 24-Month Study

10. Interim Guidelines for Operation of Lake Powell and Lake Mead In place for an interim period (through 2026) Key provisions: –Operation for Lake Powell and Lake Mead is specified throughout the full range of operation –Strategy for shortages in the Lower Basin is specified, including a provision for additional shortages if warranted –Mechanism (Intentionally Created Surplus or ICS) is established to encourage efficient and flexible water use in the Lower Basin

11. Lake Powell & Lake Mead Operational Diagrams and Current Conditions 4/18/10 1,09911.42 4/18/10 3,61913.63 4/18/10

12. Min Power Pool 3,490 ft 3,642 ft 13.74 maf (57% of Live Capacity) 3,370 ft Dead Pool Lake Powell Capacity 3,700 ft 24.3 maf Dead Pool (1.9 maf) Inactive Pool (4.0 maf) Not to scale 80 ft 130 ft As of Apr 25, 2010 3,575 ft Lower Elevation Balancing Tier Mid-Elevation Release Tier 3,525 ft Equalization Tier Upper Elevation Balancing Tier Equalization Elevation (WY 2010) 3,620 ft

13. Lower SNWA Intake 1,000 ft 1,099 ft 11.37 maf (44% of Live Capacity) 895 ft Dead Pool Elevation Lake Mead Capacity 1,219.6 ft 25.9 maf Dead Pool (2.0 maf) Not to scale 121 ft As of Apr 25, 2010 1,145 ft 24ft 1,075 ft 1 st Level Shortage Conditions 1,050 ft Surplus Conditions Normal or ICS Surplus Conditions Min Power Pool 15.9 maf 2 nd Level Shortage Conditions 3 rd Level Shortage Conditions 1,025 ft

14. Probability of Lower Basin Shortage

15. ICS may be created through extraordinary conservation measures including: –land fallowing, canal lining, desalination, importation, system efficiency There is a 5% system assessment when ICS is created (except for system efficiency projects) Delivery of ICS may occur in years after creation Intentionally Created Surplus (ICS) Construction of the Drop 2 Storage Reservoir

16. Colorado River Water Supply & Demand

17. Colorado River Basin Water Supply and Demand Study Two-year, $2 million study cost shared by Reclamation and the Basin States Objectives: Define current and future imbalances in water supply and demand Assess the risks to Basin resources Develop and evaluate adaptation and mitigation strategies A transparent, collaborative study with input from all stakeholders

18. Colorado River Reservoir Operations Additional Information: http://www.usbr.gov/lc/riverops.html http://www.usbr.gov/lc/region/programs/ crbstudy.html

19. CWAG 2010 WATER LAW CONFERENCE The Broadmoor Colorado Springs, Colorado April 29 – 30, 2010