Urban Water Institute August 27, 2015 Managing the Colorado River during Drought

Scale of the Drought We remain in the worst drought in over 100 years of written record keeping The period from 2000 through 2015 has been the driest 16-year period ever recorded in the Lower Colorado River Basin Paleo studies indicate the current drought is one of the worst in the Basin in the past 1200 years The risk of a shortage condition in the Lower Basin is approximately 47% in 2017 Basin Study projects a 3.2 million acre-foot (MAF) gap between supply and demand by 2060 Photo: Lake Mead, February 23, 2015: Elevation 1,089 ft. Current elevation as of August 17, 2015 : 1,078 ft. 2

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5 Powell-Mead Percent Capacity 1999 – 2015 Year % Year % Scale of the Drought continued Powell and Mead, the two largest reservoirs on the Colorado River comprise 83% of total River system storage End of year 2015 percent capacity is projected based on the August Month Study

Further System Conservation Drought Response Action Plan Use of Interim Guidelines Coordination with Mexico Drought Response 6

2007 Interim Guidelines Record of Decision issued in December 2007 officially adopting the Guidelines Culmination of a multi-year process that began in 2005 to develop consensus plan to mitigate the drought Key components:  Lower Basin Shortage Criteria: Shortage volumes associated with Lake Mead elevations to conserve storage and provide greater certainty to know when and by how much water deliveries will be reduced in low reservoir conditions  Coordinated Operations: For Lake Powell and Lake Mead through a full range of reservoir levels that minimize shortages in the Lower Basin and avoid the risk of curtailments in the Upper Basin  Intentionally Created Surplus (ICS): Mechanism to encourage and account for augmentations and conservation of water supplies  In place for an interim period through 2026 Guidelines still sound and effective; the breadth and deep of the drought however have necessitated additional actions 7

Interim Guidelines continued Shortage Sharing Arizona and Nevada share Lower Basin shortages under the 2007 Interim Guidelines Mexico voluntarily agreed in Minute 319 to the 1944 Water Treaty to accept reductions in its deliveries at the same elevations Lake Mead Elevation Arizona Reduction (acre-feet) Nevada Reduction (acre-feet) Mexico Reduction (acre-feet) 1075’320,00013,00050, ’400,00017,00070, ’480,00020,000125,000 Lake Mead’s elevation is 1,078 feet as of August 17,

Drought Response Action Plan Prolonged drought necessitated additional action – Reclamation’s Drought Response Action Plan Action Plan created in accordance with Memorandum of Understanding (MOU) signed December 10, 2014 between:  Reclamation, Lower Basin States (AZ, CA, NV), Major municipal utilities representing those states (Central Arizona Project, Metropolitan Water District of Southern California, Southern Nevada Water Authority) MOU calls for actions to develop 1.5 to 3.0 MAF of system water (“Protection Volumes”) for Lake Mead by the end of 2019 MOU provides first steps towards implementing pilot programs to achieve a portion of this volume by the end of 2017:  740,000 acre-feet (AF) by all parties  Including 50,000 AF by Reclamation Furthermore, “Reclamation will work to plan and implement actions to replace, recover, and reduce system losses from the Colorado River System” 9

Drought Response Action Plan continued 10 50,000 acre-feet annually by Reclamation by 2017 – early progress: YearAF , , , , , YTD*12,088 One measure of progress Excess Flows to Mexico Reservoir Uptime WOND System Efficiency Lower Salinity Water * Provisional data

Drought Response Action Plan continued 11 Beyond our commitment to 50,000 AF of water by 2017, the MOU states: “Reclamation will work to plan and implement actions to replace, recover, and reduce system losses from the Colorado River System” Accordingly, Reclamation and the Arizona Department of Water Resources partnered earlier this year to create the “Bypass Flows Workgroup” Bypass flows are agricultural return flows (about 125,000 AF annually) that can not be returned to the Colorado River  Flows are too saline  If returned to the Colorado River, the U.S. would exceed salinity limit set forth in the 1944 Water Treaty Workgroup is developing options for potentially resolving the majority of the bypass flows

Further System Conservation 12 $11 million Pilot System Conservation Program $8.25M Lower Basin > 50 entitlement holders invited to propose 20 pre-proposals received 6 agreements moving forward for ,000 acre-feet Memorandum of Understanding July ,000 acre-feet = 1 foot in Lake Mead at its current elevation

Coordination with Mexico Mid to late 2016 is the target for completion of a new Minute 13