West Salt River Valley Basin Study

Advisory Group Meeting #2

August 20, 2015

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Today’s AgendaWelcome & Opening Comments

Meeting Objectives

Basin Study Overview

Groundwater Model

Recharge Screening Analysis Study

Supply and Demand Studies

Participant Discussion

Next Steps & Action Items

Closing Comments & Adjourn

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What is WESTCAPS?• West Valley CAP Subcontractors

• Collaboration of municipal and private water providers, and interested water agencies, working together to develop regional solutions to plan for the future of water in the West Valley. 

• Our Mission is to develop a cost effective, quality water supply; engage in water resource planning and management; and develop regional partnerships for water in the West Valley.

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WESTCAPS MembersInterested Parties:

Bureau of Reclamation (BOR)

AZ Department of Water Resources (ADWR)

Central Arizona Project (CAP)

• Central Arizona Water Conservation District (CAWCD)

• Central Arizona Groundwater Replenishment District (CAGRD)

Salt River Project (SRP)

AZ State Land Department (ASLD)

Members:

Arizona Water Co

City of Avondale

City of Buckeye

City of El Mirage

EPCOR Water

City of Glendale

City of Goodyear

City of Peoria

City of Phoenix

City of Surprise

City of Tolleson

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Previous Work• Groundwater Supply Study

• Population & Water Demand Projections

• Maricopa Water District (MWD) Beardsley Canal Hydraulic Capacity Study

• Cross Drainage on the Beardsley Canal

• Infrastructure Strategic Plans

• East/West Pipeline alignment

• Regional Brackish Groundwater Study

• Recharge/Reuse Inventory

• Regional Pipeline Transmission (North/South alignment)

• Groundwater Model Integration

Funding = Studies

Available at www.WESTCAPS.org

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Key Accomplishments

Hassayampa River Recharge FacilityWhite Tanks Water Treatment Plant

• Study the amount of sustainable groundwater pumping in Buckeye Waterlogged Area

• Start integration of West Salt River Valley (SRV) and Hassayampa Groundwater Models

• Study brackish groundwater treatment plant opportunities in the Southwest Valley

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Meeting Objectives•Explain Basin Study Objectives

•Provide an Update on Progress

•Encourage Input & Discussion

•Explain Next Steps

West Salt River Valley

Basin Study

Advisory Group Update Mitchell Haws Study Manager Phoenix Area Office mhaws@usbr.gov 623-773-6274

Study Partners City of Avondale

Arizona Water Company City of Buckeye City of El Mirage EPCOR City of Glendale Global Water City of Goodyear City of Peoria City of Phoenix City of Surprise City of Tolleson

Study Advisors

Arizona Department of Water ResourcesAudubon SocietyCentral Arizona Groundwater Replenishment DistrictCentral Arizona ProjectGila River Indian CommunityRoosevelt Irrigation DistrictSRPThe Nature Conservancy

Audubon

Study Requirements

Each Basin Study will include four elements:

1. Projections of water supply and demand, including an assessment of risks to the water supply relating to climate change.

2. Analysis of how existing water and power infrastructure and operations will perform in the face of changing water realities, such as population growth and climate change.

3. Development of options to improve operations and infrastructure to supply adequate water in the future.

4. A trade-off analysis of the options identified, findings and recommendations as appropriate.

Questions for WESTCAPS Basin Study

• What is the potential for imported water supply to decrease?– Trigger thresholds in Lake Mead, Colorado River Basin Study– Will Salt River Project Reductions increase pumping?

• What is the potential for increased groundwater pumping,– due to reduced imported water supply?– due to increased demand from population growth or increased

ag demand?

• What are the probabilities of exceeding the thresholds from GW Management Act (Assured Water Supply) across the WSRV Basin?

West Salt River Valley Basin Study Will Include:

• Updated Water Demand and Supply Studies

• Updated and Combine Ground Water Model– Recharge Screening Analysis– Various Planning Scenarios– Include Climate Change Analysis

• Updated Economics Modeling

• Trade-off Analysis and Recommendations

Study Task Teams

• Supply Task Team – Christine Nunez• Demand Task Team – Jake Lenderking• Groundwater Modeling Task Team – John

Rasmussen• Climate Change Task Team – Subhrendu

Gangopadhyay• Recharge Screening Analysis Task Team – Adam

Ricks• Economics Analysis Task Team – Steve Piper

Supply Analysis

• Christine Nunez

Water Supply

• Data Compilation• Analysis Methodology

– Percent Recovery for Effluent– Types of Supplies– Future Supplies

• Demand Coorelation

Draft Report

• Supply Description• Approach to Analysis• Present, Future, & Climate Change Impacted

Availability• Data, Model, & Methods Used

Basin Study

Supply and Demand Update

August 20, 2015

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West Valley CitiesBuild-Out Water Demands, Current Water Resources, Unmet Water Demands

Unmet Water Demands

553,252 AF

Current Water Resources Portfolio

267,129 AF

Build-Out Population - 4,099,290Total Build-Out Demand – 820,381 AF

WATER PROVIDERS

AvondaleBuckeyeEl MirageGlendaleGoodyearPeoriaSurpriseEPCOR

Historic

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Water Demand and Supply

• Differences

– Previous snap shot had• Select cities• Build out population

– New Demand and Supply Study has• All population in study area• Stops at 2060

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Water Demand

• Population Projections

– MAG data• TAZ data

– Captures entire study area– Captures all population

» Ignores municipal water service areas

– Adjusted down by water provider input

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Water Demand

Population Projections * **Year 2010 2020 2030 2040 2050 2060

MAG Population 2,380,733 2,829,415 3,444,023 4,126,640 5,035,478 6,144,476

Adjusted Population 2,380,733 2,807,974 3,339,171 3,978,891 4,774,387 5,729,525

*Through 2040, extrapolated thereafter. The contents of this report reflect the views of the Licensee who is responsible for the facts and accuracy of the data presented herein. The contents do not necessarily reflect the official views or policies of MAG and have not been approved or endorsed by MAG.

** This population projection reflects the WSRV, Hassayampa, Lake Pleasant, and Rainbow Valley subbasins. It includes all of the City of Phoenix and excludes Tempe and Paradise Valley.

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Water Demand

• Projections

– Use of a weighted GPCD – 187.82• 5 year average• For existing demand

– Use of 132 GPCD for new population• 99 new residential• 21 new commercial• 12 lost water (10%)

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Water Demand

Municipal Water Demand in Acre Feet Per Year2010 2020 2030 2040 2050 2060

High Population Growth 500,859 567,200 658,076 759,007 893,387 1,057,362

Adjusted (Normal) Population Growth 500,859 564,030 642,572 737,161 854,782 996,008

Normal Population Growth with Conservation 500,859 512,365 542,287 590,398 662,659 758,645

Groundwater Modeling

• Mitch Haws

Implications for Overlap Areas• Northern Overlap

– LHSB Recharge and higher water levels

– WSRV Pumping• Southern Overlap

– Underflow from LHSB

– Waterlogged area

Climate Change Modeling

• Mitch Haws/Subhrendu Gangopadhyay

Climate Change Analysis Decisions• Historical period ,1950-1999• Future planning time horizon(s) – 1 (30-yr period centered around 2050, [2035-

2064] -> index sequential to 100-years for GW model runs)• Number of climate change scenarios - 3 (later slide), HD (hot-dry), CT (central-

tendency), WW (warm-wet)• CMIP-5 Climate Projections per scenario – 10 (used in other Studies)• Variables

– Precipitation– Temperature– Recharge – Streamflow

• Temporal resolution – monthly to annual• Spatial domain and resolution (BCSD climate projection resolution, 1/8th-degree ~

12 km)• Historical water supply and water demand - to be conducted by Study Partners

Climate Change Scenarios

Note that the values adjacent to each climate change scenario, filled red circles, represent the respective percentiles of precipitation and temperature changes calculated from the projection ensemble.

Recharge Screening Analysis

• Adam Ricks

West Salt River Valley Basin StudyRecharge Screening Analysis

• What are the impacts of reduced managed water supplies?– Triggered by thresholds established for Colorado River Basin

• What are the affects due to increased groundwater pumping?– Resulting from decreased water supplies?– Resulting from increased demand due to population growth?

• What are the probabilities of exceeding the thresholds from GW Management Act (Assured Water Supply) across the Basin?

• - Cannot pump below 1,000 foot level?

Questions for Recharge Screening Analysis

• Is recharge feasible in a future with reduced supplies?-recharge effluent and treat on recovery

• Where can recovery of stored groundwater be withdrawn?– How much water needs to be “banked” to meet changes of

increased demand with decreased supplies?– Informed by Water Supply/Demand Analysis

• Will this volume of water be achievable?-Informed by the Groundwater Modeling

Questions for Recharge Screening Analysis

• Is recharge feasible in a future with reduced supplies?-recharge effluent and treat on recovery

• Direct delivery will require ability to handle treated volume

Recharge and recovery will be heavily influenced by costs to move water to where it is needed. Screening analysis needs to optimize existing infrastructure (canals, and pipelines, treatment)

Questions for Recharge Screening Analysis

• Water Supply and Demand Analysis will help inform Groundwater Modeling

• Groundwater Modeling will be informed by climate change analysis

• All of the above will help to inform the screening for more suitable areas for recharge

• Where to site facility that optimizes existing infrastructure• Where to site facility that can meet supply and demand constraints• Where to site facility that is screened for water quality impacts• Where to site facility that is screened for available lands

• Where to recharge that optimizes existing infrastructure

• Where to recharge that can meet supply and demand constraints

• Where to recharge that is screened for water quality impacts

• Where to recharge that is screened for available lands

Next Steps for Recharge Screening Analysis

• Once WestCAPS understands the results from the Groundwater Modeling, Supply and Demand and Climate Change analyses will be able to provide the technical support to integrate the newly derived info into the recharge siting analysis.

Economic Analysis

• Mitch Haws– Contacted Reclamation’s Denver office economist– Provided Scope of Work– Denver has provided comments to the Scope of

Work with an estimate to accomplish the task– Have draft of the Advanced Funding Agreement

(AFA)– Because of the end of the Federal Fiscal Year the

AFA will be signed after October 1

Economic Analysis

• Economics of a regional treatment and transmission lines

• Impacts of water supply on residential and commercial development and housing affordability

• Population projections and impacts of unmet water demands

• OM&R for new regional infrastructure

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• Stakeholder Advisory Group

– ID Stakeholders

– ID Technical Committees

• Technical Committees

• Public Input

• WESTCAPS Meetings

• E-updates via Email

• Website: www.WESTCAPS.org

Technical Committees

& Public Input

Basin Study Advisory Group

WESTCAPSManagementCommittee

Communication Plan

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Next Steps•Draft/Finalize Supply Study

•Draft/Finalize Demand Study

•Develop Ground Water Model

•Develop and Run Climate Models

•Complete Recharge Site Suitability

Study

• Initiate Economic Analysis

Questions

Mitch Haws

Study Manager

Bureau of Reclamation

623-773-6274

mhaws@usbr.gov