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

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

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

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

5. Projected Water Supply Shortfalls
Overview of the Challenges
Projected Water Supply Shortfalls
2012

6. Basis of Evaluation
Planning Horizons
2062
2037
2012

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

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

9. *gpcd = gallons per capita per day
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. gallons per capita per day (gpcd)
Basis of Evaluation
Water Demand Projections
Projected Population
Per Capita Demand
Projected Demand X =
# of people X
gallons per capita per day (gpcd) =
gallons per day

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

12. Projected Water Demand Shortfalls
Basis of Evaluation
Projected Water Demand Shortfalls
2062 Water Demand 2037 Water Demand Available Supply
Treatment Planning
Supply Planning
151
135 72 86 60 96 69
Water Demand (mgd) 22 85 55 72 29 44 63 26 13
Average Dry
Drought
Conditions

13. Steps of Evaluation Process
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 Rural Water System (LCRWS)
Missouri River Pipeline
LCRWS w/ Limited Federal Funding
Missouri River Pipeline w/ Consecutive Users
LCRWS w/ Limited Expansion Capacity

15. Summary of Alternatives
Overview of LCRWS Project
Initial Capacity 10 MGD
System Expansion
Program Funding
Commitment

16. Summary of Alternatives
Missouri River Pipeline Concept
Future Use Permit
Water Supply Alternatives 1977
Gavin’s Point Dam

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

18. Comparison of Alternatives
PRESENT WORTH
Annual Debt Payment
Annual Incremental O&M Costs
Total Annual Debt & O&M Costs
( )
LCRWS
$548,550,000
$64,720,000
$202,590,000
$751,140,000
LCRWS w/ Limited Federal Funding
$558,300,000
$760,890,000
LCRWS w/ Limited Expansion Capacity
$570,760,000
$89,710,000
$244,600,000
$815,360,000
Missouri River Pipeline
$703,240,000
$44,560,000
$149,780,000
$853,020,000

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?