Lake Mead

Lake Powell

85%

35%

96%

61%

73%

52%, 12.74 MAF

40%, 10.47 MAF

1,220’

3,700’

3,610

Colorado River Water Supply ReportSystem Contents: 28.36 MAF4/23/18

2018 Equalization Level 3,654’

Tier 1 Shortage 1,075’

1,085’

Reservoir Current Change MaximumLake Mead 10.47 - 0.23 25.90Lake Powell 12.74 - 0.28 24.30Flaming Gorge Reservoir 3.18 - 0.01 3.75Navajo Reservoir 1.23 - 0.01 1.70Blue Mesa Reservoir 0.50 - 0.04 0.83Fontenelle Reservoir 0.12 0.00 0.34Morrow Point Reservoir 0.11 + 0.01 0.12

Reservoir Capacities (MAF)

As of 4/24/2018, the current SWE is at 80% (9.8 in) ofthe long-term median (1981-2010) of the water yearto date (12.3 in). When compared to the seasonallong-term average (14.2 in) the current SWE is at 69%of the entire season for the current water year (2018).

Snowpack Conditions

Lake Powell ElevationsLake Powell is currently operating under theUpper Elevation Balancing Tier for Water Year2018. The 2018 April 24-month studydetermined releases from Lake Powell for thewater year will be adjusted up to 9 MAF. Allprojections from the April 24-month studyindicate that Lake Powell releases for WaterYear 2019 will follow an Upper ElevationBalancing Tier pattern.For Water Year 2020, the most and maximumprobable projections suggest that Lake PowellReleases will again follow an Upper ElevationBalancing Tier pattern. However, theminimum probable projection for Water Year2020 suggests Lake Powell will operate undera Mid-elevation Release Tier pattern.

Per the 2007 Guidelines, Lake Mead will be operated under the Normal - Intentionally Created Surplus (ICS) Surplus Condition criterion. Based on the 2018 April 24-Month Study minimum, maximum, and most probable projections, Lake Mead will be above the Tier 1 Shortage trigger elevation of 1,075 ft. at the end of calendar year 2018. This would indicate that Mead would not be in Shortage operations for 2019.

Lake Mead Elevations

At the end of calendar year 2019, the maximum probable case shows Lake Mead’s elevation above 1,075 ft. The minimum probable case shows the possibility of Lake Mead’s elevation being below 1,075 ft., meaning that 2019 could be operated under Tier 1 Shortage criterion.

The most probable case Lake Mead elevation is just below 1,075 ft.; however this does not consider conservation activities in 2018 or 2019. Assuming Arizona conservation of 200 kAF in both 2018 and 2019 under the most probable case, Lake Mead’s elevation is projected to end 2019 above 1,075 ft. to prevent Shortage operations in 2020.

August 2018: Determination of 2019 Mead Operations

October 2018: CAP Compiles 2019 Water Orders

November 2018 –March 2019: Snow Accumulation Season & Runoff Forecasts (significant signals as early as mid-February)

April 2019: Inflow Forecast Update (significant signal for risks for 2020 shortage)

May 2019: Potential for water rate update based on shortage risk

August 2019 Determination of 2020 Mead Operations

October 2019: CAP compiles 2020 Water Orders

January 2020Mead

Operations

CAWCD Shortage Preparedness: Potential Timeline

CAWCD Shortage Preparedness Steps:May 2018 – January 2020

• Track hydrologic signals and runoff/inflow forecasts• Communicate risks with customers and stakeholders• Work with customers/stakeholders to share

information on possible impacts to water orders and deliveries

• Work with customers/stakeholders to communicate and discuss possible financial impacts from a shortage and available tools to mitigate those impacts

• Outline policy discussions on questions that may stem from shortage operations.