1. West Salt River Valley Basin Study Advisory Group Meeting #2 August 20, 2015

2. 2 Today’s Agenda Welcome & 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

3. 3 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.

4. 4 WESTCAPS Members Interested 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

5. 5 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.orgwww.WESTCAPS.org

6. 6 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

7. 7 Meeting Objectives Explain Basin Study Objectives Provide an Update on Progress Encourage Input & Discussion Explain Next Steps

8. West Salt River Valley Basin Study Advisory Group Update Mitchell Haws Study Manager Phoenix Area Office mhaws@usbr.gov 623-773-6274

9. 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

10. Study Advisors Arizona Department of Water Resources Audubon Society Central Arizona Groundwater Replenishment District Central Arizona Project Gila River Indian Community Roosevelt Irrigation District SRP The Nature Conservancy Audubon

11. 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.

12. 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?

13. 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

15. 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

16. Supply Analysis Christine Nunez

17. Water Supply Data Compilation Analysis Methodology – Percent Recovery for Effluent – Types of Supplies – Future Supplies Demand Coorelation

18. Draft Report Supply Description Approach to Analysis Present, Future, & Climate Change Impacted Availability Data, Model, & Methods Used

20. Basin Study Supply and Demand Update August 20, 2015

21. 21 West Valley Cities Build-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 - 4,099,290 Total Build-Out Demand – 820,381 AF WATER PROVIDERS Avondale Buckeye El Mirage Glendale Goodyear Peoria Surprise EPCOR

22. 22 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

23. 23 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

24. 24

25. 25 Water Demand Population Projections * ** Year201020202030204020502060 MAG Population2,380,7332,829,4153,444,0234,126,6405,035,4786,144,476 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.

26. 26 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%)

27. 27 Water Demand Municipal Water Demand in Acre Feet Per Year 201020202030204020502060 High Population Growth500,859567,200658,076759,007893,3871,057,362 Adjusted (Normal) Population Growth500,859564,030642,572737,161854,782996,008 Normal Population Growth with Conservation500,859512,365542,287590,398662,659758,645

28. Groundwater Modeling Mitch Haws

29. Implications for Overlap Areas Northern Overlap – LHSB Recharge and higher water levels – WSRV Pumping Southern Overlap – Underflow from LHSB – Waterlogged area

32. Climate Change Modeling Mitch Haws/Subhrendu Gangopadhyay

34. 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, 1/8 th -degree ~ 12 km) Historical water supply and water demand - to be conducted by Study Partners

35. 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.

36. Recharge Screening Analysis Adam Ricks

37. West Salt River Valley Basin Study Recharge 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?

38. 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

39. 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)

40. 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

41. Where to recharge that optimizes existing infrastructure

42. Where to recharge that can meet supply and demand constraints

43. Where to recharge that is screened for water quality impacts

44. Where to recharge that is screened for available lands

45. 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.

46. 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

47. 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

48. 48 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 WESTCAPS Management Committee Communication Plan

49. 49 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

50. Questions

51. Mitch Haws Study Manager Bureau of Reclamation 623-773-6274 mhaws@usbr.gov