Colorado River Basin Water Supply Outlook
Lake Powell
Lake Mead State of the System (1999-2010)
Unregulated Inflow into Lake Powell Powell-Mead Storage and Percent Capacity 50 100%
45 90%
40 80%
35 70% Percent Percent Capacity 30 60%
25 50%
20 40% Volume in in MAF Volume 15 30%
109% 10 104% 102% 20% 88% 71% 70% 73% 5 62% 59% 10% 52% 49% 25%
0 0%
2004 2005 2006 2007 1999 2000 2001 2002 2003 2008 2009 2010
End of Water Year
Powell and Mead Storage (MAF) Unregulated Inflow into Powell 1 (MAF) Powell and Mead Percent Capacity 1 The percent values at the top of the light blue bars represent the percent of average unregulated inflow into Lake Powell for a given water year based on the 30-year average from 1971 to 2000. La Nina Year ? ! ? Good ? Bad ?
Upper Colorado River Basin
Lake Mead Lake Powell
Lower Colorado River Basin Upper Colorado River Basin
Lake Powell Lake Mead
Lower Colorado River Basin
Colorado River Basin Water Supply Outlook
April to June 2011 Inflow Into Lake Powell – 11.5 MAF (145% of Normal).
Water Year 2011 Inflow Into Lake Powell - 13.1 MAF (110% of Normal).
Water Year 2011 Release from Lake Powell – 11.6 MAF Release to the Lower Basin (“Equalization” Release – based on 2007 Interim Operating Guidelines).
Lake Powell and Lake Mead Storage will generally rise for the next several years.
Lake Mead End of Month Elevation Projections from April 2011 24-Month Study Inflow Scenarios 1,155
1,145
1,135
1,125
1,115
1,105
1,095
Elevation (ft) Elevation 1,085 First Shortage Elevation 1,075
1,065 April 2011 Probable Minimum (11.35 maf release from Lake Powell in WY 2011) April 2011 Most Probable (11.56 maf release from Lake Powell in WY 2011) 1,055 April 2011 Probable Maximum (12.36 maf release from Lake Powell in WY 2011) Historical Elevations
1,045
11 11
11
11
11 11 11
11
10 11 11 11
11
10 10
10
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-
-
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Jul
Oct
Oct Jan Apr
Mar
Jun Feb
Sep Dec
Nov Sep
Dec
Nov May Aug The projected elevations in this graph are based on reservoir modeling under three possible inflow scenarios: 1) The minimum probable inflow scenario reflects a dry hydrologic condition which statistically would be exceeded 90% of the time; 2) the most probable inflow scenario reflects a median inflow condition which statistically would be exceeeded 50% of the time; and 3) the maximum probable inflow scenario reflects a wet hydrologic condition which statistically would be exceeded only 10% of the time. There is approximately an 80% probability that the future elevation will fall inside the shaded region. There are possible inflow scenarios that would result in reservoir elevations falling outside the range indicated in this graph. Colorado River Basin Water Supply Outlook
Total Reservoir System Contents: 31.6 MAF or 53%
Total Reservoir System Contents Last Year:
Lake Powell 32.9 MAF or 55%
Lake Mead LAKE POWELL Capacity – 24.5 MAF 05/02/2011 - 53% full Contents 12.9 MAF Elevation – 3,612’
Glen Canyon Dam
Page LAKE MEAD Capacity - 26 MAF 05/02/2011 - 43% full Contents – 11.1 MAF Elevation - 1,096’
Las Vegas
Hoover Dam Lower Colorado River Basin Chance of a Shortage 100%
90%
80%
70%
60%
50%
40%
30%
20%
10%
0% 2011 2012 2013 2014 2015 2016 2017 2018 2019 2020 2021 2022 2023 2024 2025 2026
Source: Bureau of Reclamation Lake Mead Key Operational Elevations – Interim Period
1220’ (95% full) FLOOD CONTROL OR QUANTIFIED SURPLUS (“70R”) 1200’ (84% full)
DOMESTIC SURPLUS 1145’ (56% full)
NORMAL OPERATIONS 1075’ (34% full) 400 KAF SHORTAGE (333 KAF to U.S.) (320 KAF to Arizona) Minimum Power Pool and Bottom of First SNWA Intake 1050’ (27% full) 500 KAF SHORTAGE (417 KAF to U.S.) (400 KAF to Arizona) 1025’ (21% full) 600 KAF SHORTAGE (500 KAF to U.S.) (480 KAF to Arizona) Bottom of Second SNWA Intake 1000’ (16% full) Minimum Mead Intake RECONSULTATION Elevation 915’ (2% full) (For Additional Shortages) Top of Dead Storage 895’ (0% full) What About Next Year? La Nina Year ? ! ? El Nino Year ? ! ?
El Nino
La Nina
El Nino
La Nina