© 2014 HDR, Inc., all rights reserved. Catawba-Wateree Water Supply Master Plan

 2006 Water Supply Study found maximum capacity of Catawba River Basin for water supply could be reached mid-century  Catawba-Wateree Water Management Group incorporated - December 2007  Water Supply Master Plan commissioned in 2010  Purpose of Master Plan is to find ways to extend the time before the capacity of the Basin is reached Background

 4,750 square miles  Supports nearly two million people with water for drinking, power generation, industrial processes, crop and livestock production, recreation, irrigation, and more The Catawba-Wateree River Basin

Project was funded by:  Duke Energy Foundation  North Carolina Department of Environment and Natural Resources  South Carolina Department of Natural Resources  Catawba-Wateree Water Management Group Acknowledgements/Thanks

 Supplemental funding  Stakeholder input  Water use projections  Refinement of hydrologic model  Climate change impacts  Develop & evaluate options  Action plan and schedule  Publish report  Implementation, on-going public input  Periodic future updates Elements of the Master Plan

 Advisory level input by key organizations with an interest in future planning efforts for the Basin  Intended to ensure a broad level of input from a diverse group of interested stakeholders Stakeholder Advisory Team (SAT)

 Million gallons per day (mgd) consumed and percent of total mgd How Water will be Used (2065) Steam/Electric Power 178.3, 43% Industrial 7.7, 2% Public Water Supply 198.5, 47% Agriculture/Irrigation 34.9, 8%

Water Use Projections

 Safe Yield Study o How to define and determine safe yield o Can safe yield be increased?  Sedimentation Monitoring Study  Water Use Efficiency Study  Low Inflow Protocol Response Evaluation Study  Full reports can be found at Pre-Master Plan Project Research

Sensitivity Analysis  Evaluated variation in population growth  Evaluated climate change impacts o No impacts o Baseline (moderate) impacts – focused on temperature rise o High impact – temperature rise and reduced precipitation/inflow  CWWMG – First in the region to incorporate climate change into water use planning Population and Climate Change

Playing the “What If?” Game with a Robust Water Model  Baseline  Population growth  Climate change  Public water supplier water use changes (water use efficiency, reroute wastewater)  Power consumptive water use changes (e.g. relocation of demand)  New off-stream storage reservoirs  Critical intake modifications  Effluent flow recycling  Modified reservoir operations  Low Inflow Protocol (drought management plan) modifications Individual and Integrated Future Planning Scenarios

 Improve safe yield of the Basin by over 200 mgd  Extend water yield by 40 years Results and Recommendations

 Increase water use efficiency  Lower critical water intakes/elevations o Power plant o Public water supply  Raise target lake levels during summer months  Enhance drought responsiveness through Low Inflow Protocol Key Recommendations

 Example: average per capita use in the Charlotte-Mecklenburg system o Current ~100 gallons/day/person (residential) o Recommended 2065~80 gallons/day/person (residential) Water Use Efficiency Recommendations

Where’s the Water Going? CW Reservoir System Water Balance Wateree Hydro Station outflows 3,359 mgd (1,085 mgd) Natural surface evaporation 204 mgd (all eleven lakes combined) (204 mgd) Surface and groundwater inflow 3,752 mgd (1,491 mgd) Public Water Supply 92 mgd (98 mgd) Industrial 3 mgd (6 mgd) Thermal Power 74 mgd (78 mgd) Irrigation 20 mgd (20 mgd) Water withdrawals are average net amounts for 2006–2013 and total 189 mgd (202 mgd) Natural inflow, natural evaporation, and hydro outflow are annual average amounts from hydrology data set used in CHEOPS™ model * mgd = million gallons per day. To convert to cubic feet per second (cfs), multiply all numbers by Values in italics represent corresponding inflow, withdrawals, and outflow for the worst 12 months during the drought (7/01/2007 to 6/30/2008)

So What is Duke Energy’s Role? Manage the Water Resource  Manage the region’s raw water supply (big, ongoing investment)  Implement Comprehensive Relicensing Agreement (CRA) and new license  Continue making electric customers more energy-efficient. In , Duke Energy’s energy conservation programs across the Carolinas o Reduced capacity needs by total of ≈ 1,200 MW (about a nuclear unit) o Reduced energy needs by total of ≈ 2,442,000 MWh (about a billion gallons of water equivalent)

So What is Duke Energy’s Role? Be a Good Partner  Remain a dues-paying, active member of the Catawba-Wateree Water Management Group  Help provide leadership and coordination Implement the Water Supply Master Plan  Pursue the identified initiatives o Water use for thermal plant replacements/additions o Quicker response in Low Inflow Protocol o Increase summer target elevations for selected reservoirs

 Implementation of the Catawba-Wateree Water Supply Master Plan extends the River’s capacity to sustain growth through 2100 Projected Results

Complete Water Supply Master Plan Report is available at Questions?

 Additional slides for further discussion Reference

Once-Through Cooling  Used at Marshall, McGuire and Allen Steam Stations  Pros (compared to cooling towers) o Much more water use efficient o Higher plant efficiency o Thermal refuge for fish in cold months  Cons (compared to cooling towers) o Heats up the lake (regulated by permit) o Higher risk to fish (impingement and entrainment) Thermal Power Cooling Technologies Used on the CW

Cooling Towers (aka Closed Loop Cooling)  Used at Catawba Nuclear Station  Pros (compared to once-through cooling) o Much lower gross water withdrawal rate o Negligible thermal impact to the lake o Reduced risk of impacting fish  Cons (compared to once-through cooling) o Consumes 30-40% more water per unit of electricity produced o Lower plant efficiency Thermal Power Cooling Technologies Used on the CW

Growth  Future electrical demand projected to double in next 50 years  Energy efficiency success  Thermal power will be a key source  CW lakes will support some portion of growth Power Plant Retirements, Replacements and Additions  Natural gas - most replacement and new plants in WSMP are more water use efficient (gas-fired combined cycle) than existing plants  Moving downriver - located water withdrawals for some new plants further down the river system Research and Development  Water Research Center, Cartersville, GA  Technologies must be proven regionally viable, reliable and cost-effective at plant scale  Cooling system modification at SCE&G’s Wateree Steam Station does not reduce water consumption Factors Driving Future Thermal Power Cooling Water Use