Colorado River Reservoir Storage: Reliability, Resilience and Response

Transcription

1 Colorado River Reservoir Storage: Reliability, Resilience and Response April 23, 2016 Desalination Conference Green Desalination for a Water-Secure Nevada College of Southern Nevada, Las Vegas, Nevada 1

2 Important Disclaimer All views and opinions expressed today in this presentation are mine. Nothing stated or presented can or shall be interpreted or construed to reflect, in any manner whatsoever, any view, position or official policy of the Bureau of Reclamation of the Department of the Interior or any agency of the U.S. Government. Opinions expressed are solely my own and do not express the views or opinions of my employer. 2

3 Colorado River Basin Water Overview/Synopsis 60 million acre-feet (MAF) of reservoir storage capacity 16.5 MAF allocated annually in the U.S & Mexico 13 to 14.5 MAF of annual consumptive use 14.8 MAF of average annual natural inflow into Lake Powell over past 110 years Annual inflows highly variable from year-to-year (5 to 24 MAF)

4 4 Natural Flow Colorado River at Lees Ferry Gaging Station, Arizona Water Year 1906 to 2016

5 State of the System (Water Years ) 1, Unregulated Inflow into Lake Powell Powell-Mead Storage and Percent Capacity 100% 90% 80% 70% Volume in MAF % 60% 50% 40% 30% Percent Capacity % 118% 20% % 65% 24% 57% 55% 80% 81% 112% 94% 78% 45% 47% 96% 94% 78% 10% 0% End of Water Year Powell and Mead Storage (MAF) Unregulated Inflow into Powell (MAF) Powell and Mead Percent Capacity 1 Values for Water Year 2016 are projected. Unregulated inflow is based on the latest CBRFC forecast dated April 18, Storage and percent capacity are based on the April 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

6 Colorado River Drought has been the driest 16-year period in over 100 years of historical records ( are estimated) Tree-ring reconstructions show more severe droughts have occurred over the past 1200 years (e.g., drought in the mid-1100s) The 2016 April through July runoff forecast of 5.3 MAF is 74% of average 1 as of April 18, 2016 Not unusual to have a few years of above average inflow during longer-term droughts (e.g., the 1950s) 1 Percent of average is based on the period of record from

7 Lake Mead End of Month Elevation 1,225 Spillway Crest 1221 ft 1,200 1,175 1,150 September % of Capacity Elevation (ft) 1,125 1,100 1,075 1,050 Prior to 1999, Lake Mead was last at elevation 1, feet in June 1937 March % of capacity 1,025 In June 2015, Lake Mead was at its lowest elevation of 1, feet since it was first filled in the 1930s. 1, During the 1950s drought, Mead reached a low of 1, feet in April January March 2016

8 Current Basin Reservoir Storage Reservoir Percent Full Storage (MAF) Elevation (Feet) Flaming Gorge 85% ,026 Lake Powell 45% ,591 Lake Mead 38% ,078 Total System Storage* 48% NA 8

9 1,219.6 Key Lake Mead Elevations 26.1 maf 1,145 ft 1,106 ft 1,075 ft 1,050 ft Surplus Conditions Normal or ICS Surplus Conditions 1,078 ft Shortage Conditions 28 ft ft 16.2 maf of vacant reservoir space 9.86 maf (38% of Live Capacity) 1,000 ft SNWA Intake 1000 Min Power ft Dead Pool 895 Dead Pool (2.5 maf) SNWA Intake As of Apr 23, 2016 Not to scale

10 Between Lake Mead and Lake Powell, over 50 MAF are in storage when they re full. This photograph shows Lake Mead (at elevation 1,225.6 ) with 13,240 cubic feet per second flowing over each spillway on July 27,

11 11

12 Projected Reservoir Conditions

13 13

14 Observation: The water supply for the Colorado River Basin, and more specifically for the Lower Colorado River Basin, has been reliable. The project purposes of the Boulder Canyon Project Act (1928), the Colorado River Storage Project (1956) and the Colorado River Basin Project Act (1968) continue to be effectively discharged. Water remains in storage even though the Basin has suffered through the past 16 years of the most severe drought of record. 14

15 Addressing/Improving the Resilience of Water Supplies Systems Measures of Water Distribution System Resilience Office of Research & Development, National Homeland Security Research Center 15 EPA 600/R-14/383 January

16 16 Committee on the Scientific Bases of Colorado River Basin Water Management; Water Science and Technology Board; Division on Earth & Life Studies; National Research Council

17 Entsminger: The biggest challenge is clearly the drought on the Colorado River. It s 90 percent of our community s water supply and that s driving almost everything we do, in particular, $1.5 billion in new infrastructure out of Lake Mead. Over the last 15 years, while our population increased by 25 percent, our aggregate water usage went down by 30 percent and our per capita usage went down by 43 percent, which is fantastic and why we re in such a strong position. Conservation is an upside-down business model. We re paying people not to use our product. A lot of our costs are fixed and I think that is the single biggest public relations challenge we face. It s that conservation conundrum. Quotation above by John Entsminger, General Manager, Southern Nevada Water Authority from Industry Focus: Utilities article included in Nevada Business, the Decision Maker s Magazine, February 2016 Online at: nevadabusiness.com 17

18 The Southern Nevada Water Authority is actively addressing challenges associated with improving the resilience of Southern Clark County s water supply. 18

19 Improving the Resilience of Water Supplies Real-time monitoring of use and projected demand Use-to-date & forecasted calendar year use updated each day at: Develop capacity for water systems to accept future shocks or perturbations Example: Metropolitan Water District of Southern California s Diamond Valley Reservoir providing in-basin storage if temporary disruption of the Colorado River Aqueduct Increasing portfolio diversity of water supply sources Example: Arizona Water Banking Authority Priced-based incentives to reduce water use both increasing unit water prices and rebates to adopt waterconserving technologies Partnerships to address regional watershed issues Sub-basin or basin-wide (going on, big-time) 19

20 Response Working together to preserve the existing water supply system in the face of drought, climate change and a growing population. Upper Basin contingency plan was formulated with the following goals: 20 Reduce or eliminate probability of Lake Powell reaching minimum power pool elevation through 2026 Ensure continued operation of 2007 Interim Guidelines through 2026 Respect the existing framework for administering use of Colorado River water in both the Upper Colorado River Basin and each Upper Division State. Combined with expected actions in Lower Basin, increase the synergistic benefits for the Colorado River Basin as a whole.

21 21

22 There is only one thing worse than fighting with allies and that is fighting without them. Winston Churchill Used with appreciation from: Increasing Water Supply Reliability and Watershed Resilience through Portfolios, Prices, and Partnerships by Kurt A. Schwabe, School of Public Policy, University of California Riverside 22

23 23