Future Water Supply Evaluation

1. CITY OF SIOUX FALLS, SOUTH DAKOTA Future Water Supply Evaluation Presented to Sioux Falls City Council February 7, 2005

2. Overview of the Challenges Basis of Evaluation Summary of Alternatives Comparison of Alternatives Conclusions and Recommendations Outline Future Water Supply Evaluation

3. Overview of the Challenges Population Growth Increased Water Demands =

4. Overview of the Challenges Susceptibility of Water Supplies to Dry Climate Conditions

5. Overview of the Challenges Projected Water Supply Shortfalls 2012

6. Basis of Evaluation Planning Horizons 2062 2037 2012

7. Basis of Evaluation Past Population Growth Trends 2004 Pop.137,500 2.5% Average Growth 1900 Pop.10,266 Actual Census Population YEAR

8. Basis of Evaluation Population Projections 2062443,303 pop. 2037281,024 pop. 2012166,398 pop. 2.06% to 1.71% 2025 2062

9. Basis of Evaluation Water Demand Projections 2002 Peak Day = 52.1 mgd (387 gpcd) 387 387 387 387 341 304 Water Demand (gpcd*) 195 155 Conditions *gpcd = gallons per capita per day

10. Basis of Evaluation Water Demand Projections ProjectedPopulation Per CapitaDemand ProjectedDemand = X # of people gallons per capita per day(gpcd) gallons per day = X

11. Basis of Evaluation Water Demand Projections Basis of Water Treatment Planning Basis of Water Supply Planning

12. Basis of Evaluation Projected Water Demand Shortfalls 2062 Water Demand2037 Water Demand Available Supply Treatment Planning Supply Planning 151 135 72 86 60 96 69 Water Demand (mgd) 22 85 55 29 44 72 63 26 13 Drought AverageDry Conditions

13. Basis of Evaluation Steps of Evaluation Process • Identification of Infrastructure Capacity Requirements • 2037 Planning Horizon • 2062 Planning Horizon • Water System Concept Development • Supply (surface water vs. groundwater) • Transmission Pipelines Pumping/Storage Facilities • Water Treatment Facilities • Delivery to the Sioux Falls WPP • Preparation of Opinions of Total Probable Project Costs • Estimation of Incremental O & M Costs

14. Summary of Alternatives Considered Alternatives Lewis & Clark RuralWater System (LCRWS) Missouri River Pipeline LCRWSw/ Limited Federal Funding Missouri River Pipelinew/ Consecutive Users LCRWSw/ Limited Expansion Capacity

15. Summary of Alternatives Overview of LCRWS Project Initial Capacity10 MGD System Expansion Program Funding Commitment

16. Summary of Alternatives Missouri River Pipeline Concept FutureUsePermit Water SupplyAlternatives1977 Gavin’s Point Dam

17. Comparison of Alternatives Capital Cost Comparison(2004 Dollars)

18. Comparison of Alternatives Comparison of Alternatives

19. Conclusions and Recommendations • A water supply shortage is projected by year 2012 and will become more pronounced with anticipated community growth • Securing near-, mid-, and long-term supplemental water supplies is recommended • The LCRWS Alternative is least costly on a present worth analysis basis • Continued participation in the LCRWS Project is recommended • Interim financing may be necessary to receive initial water service from LCRWS

20. Conclusions and Recommendations • The initial capacity received from LCRWS is projected to meet water supply demands through year 2016 • Additional capacity may be available through expansion of the LCRWS and is more cost-effective than independent supplemental water supply strategies • A commitment from LCRWS regarding the magnitude and timeline of additional capacity should be obtained as soon as possible • Eventually, an independent supply from the Missouri River will be required • Due to uncertainties of expanding the LCRWS, planning efforts to obtain supplemental capacity from the Missouri River should be initiated

21. Questions?