defining and enhancing the safe yield of multi-use, multi

catawbawatereeWMG.org catawbawatereeWMG.org

Defining and Enhancing the Safe Yield of Multi-use, Multi-Reservoir

Systems

April 28, 2014

Catawba-Wateree Water Management Group (CWWMG) Barry Gullet, CMUD & CWWWMG

HDR Engineering McKim & Creed Engineers

catawbawatereeWMG.org

Presentation Agenda

• Basin Overview

• Master Plan Key Elements

• Initial Results

• Integrated Future Water Scenarios

• Discussion

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Acknowledgements • Master Plan Funding Sponsors

– Duke Energy Foundation

– NC Department of Environment and Natural Resources

– SC Department of Natural Resources

• Safe Yield Research Project

– Water Research Foundation

• Consultant Team

– HDR Engineering

– McKim and Creed Engineers

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catawbawatereeWMG.org 4

The Catawba-Wateree River is one of America’s hardest working rivers

Water supply for: 1.5 million people in 17

counties 45% of Duke Energy’s

generating capacity in the Carolinas

Recreational interests Industrial production Agricultural/irrigation


Multi-Use, Multi-Reservoir System

- 13 Hydroelectric Stations

- 11 Interconnected Reservoirs

- 831 MW Hydropower

- 8,167 MW Nuclear and Fossil

- Drinking water for 1.5 million people

- FERC Licensed Hydro Project


Catawba-Wateree Water Management Group (CWWMG)

• Identify, fund and manage projects

• Extend and enhance the capacity of the Catawba and Wateree Rivers

• Meet human needs while maintaining the ecological health of the waterway

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Member Organizations

• Town of Granite Falls

• City of Hickory

• City of Lenoir

• Lincoln County

• Town of Long View

• City of Morganton

• Town of Mooresville

• City of Mount Holly

• City of Statesville

• Town of Valdese

• Duke Energy Carolinas

• City of Camden

• Catawba River Water Supply Project

• Chester Metropolitan District

• Lugoff-Elgin Water Authority

• City of Rock Hill

• City of Belmont

• City of Charlotte

• City of Gastonia

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Basin-Wide Water Supply Master Plan

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Goal – Develop plan to extend safe yield of the Catawba-Wateree River

(complete)


Stakeholders

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Master Plan Key Elements

• Future water demand projections

• Water modeling

• Future modeling scenarios

• Low inflow protocol modification recommendations

• Climate change impacts integration

• Water supply regionalization

• Safe yield enhancement strategies

• Stakeholder advisory team

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Low Inflow Protocol (LIP)

• Component of Duke Energy’s future FERC License

• Purpose is to reduce water usage during drought

• Developed by Duke and Relicensing Stakeholders

• Implemented voluntarily during 2007 drought

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LIP Required Actions

• Actions required by Duke and water utilities

• Progressive reduction of flows released from dams

• Progressive restrictions on water use

• Progressive reductions to minimum lake levels

• Progressively increase communication with customers

• Increase communications between water utilities and Duke Energy

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catawbawatereeWMG.org 14

Pre-Master Plan Project Research

• How to define and determine Safe Yield

• Can Safe Yield be increased?

• Full report can be found at http://catawbawatereewmg.com/


Safe Yield Factors


Climate Change Analysis

• Used Global Climate Change Impacts in the United States report (Karl, Melillo and Peterson 2009)

• Low Emissions and High Emissions Scenarios

• For Catawba-Wateree Basin

– Temperatures predicted to rise 5 – 8 degrees by 2100

– Precipitation change uncertain – assume no change

– Evaporation rates increase by 17% - 26%

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Climate Change Impact • Assume climate changes do not trigger change

in water demand

• Low Inflow Protocol is major factor

• Low Emissions Scenario

– No change to Safe Yield (Base line is 638 – 692 mgd for upper 7 reservoirs)

• High Emissions Scenario

– Reduces Safe Yield by 74 mgd

– Shifts time to reach Safe Yield by about 10 years

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C-W Basin - Net Withdrawal Total Basin

Comparison of Revised Projections to Previous Projections

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0.0

50.0

100.0

150.0

200.0

250.0

300.0

350.0

400.0

450.0

500.0

2000 2005 2010 2015 2020 2025 2030 2035 2040 2045 2050 2055 2060 2065 2070

Ne

t W

ith

dra

wal

(M

GD

)

Comparison of Catawba-Wateree Basin Studies Net Withdrawal for All Subbasins and All Categories

2006 Historical 2006 Projected 2012 Historical 2012 Projected


CHEOPS Modeling Input to New Baseline

Duke Energy’s CRA

2002 DOR

2006 WSS Projections

Duke Energy’s CRA

2007 DOR

C-W WSMP Projections

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No Climate Change Impact

Climate Change Impact on Supply


LIP w/ Mods

•Duke Response •PWS Reductions

Additional Updates to Conform to NC SL 2010-143, Secure EMC Approval, and per NC/SC Settlement Agreement

Negative

Positive

Positive

Negative

Impact to Water Supply


Population Projections

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Individual Future Scenarios • Baseline

• Population growth

• Public water supplier water use changes

• Power consumptive water use changes

• Climate change

• Critical intake modifications

• Effluent flow recycling

• Modified reservoir operations

• Low inflow protocol modifications

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Integrated Future Scenarios

• 27 individual scenarios were combined into 5 integrated future scenarios

• Looked at combination of changes on safe yields

– What if climate change impacts and more rapid growth occur?

– What if critical lake intakes are lowered and demand strategies are employed?

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Integrated Future Scenarios

• Planning Level

– Lower critical intakes and raise some summer lake levels

– Pushes safe yield date to 2095

• Best Case Scenario

– Lower critical intakes and raise some summer lake levels

– Pushes safe yield date into next century

• Worst Case Scenario

– Lower critical intakes and raise summer lake levels

– Pushes safe yield date to 2065

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Future Planning Scenarios

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MP-01 Planning Case

MP-02 Best Case

MP-03 Worst Case

Baseline Population Growth / Demand (PG-01)

Slow Population Growth (PG-02)

Rapid Population Growth (PG-03)

Baseline Climate Change (CC-01)

No Climate Change Multi-Model Ensemble Climate Change (CC-03)

Lower Lake James Critical Elevation (Bridgewater Powerhouse) (CI-02)



Modified ‘Failure’ of Intake as to Below Critical Intake Level by 0.1’ or more


Future Planning Scenarios

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Action Basin Failure Decade

2015 2025 2035 2045 2055 2065 2075 2085 2095

MP-01 Planning Case

Norman Mtn Island

Wylie

MP-01M Mitigated Planning Case

Mtn Island

MP-02 Best Case

Wylie

MP-02 M Mitigated Best Case

MP-03 Worst Case

Wylie

MP-03Ma Mitigated Worst Case A

Wylie

MP-03Mb Mitigated Worst Case B

Mtn Island Wylie


Mitigated Planning Case

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Action Schedule

2015 2025 2035 2045 2055 2065

High End Water Use Efficiency (Resid. & Wholesale) (WC-01D)

Establish WUEP

Continue Monitor

Continue Monitor

Continue Monitor

Reduction Goal Year 2056

Lower Upper Catawba Intakes (CI-01)

Feasibility/ Predesign

Financing/ Permitting

Design and Construction

Complete by 2045

Lower Lake Norman Critical Intake (CI-03) Operations

Change

Lower Lake Wylie Critical Intakes (CI-04) Feasibility/ Predesign

Financing/ Permitting

Design and Construction

Complete by 2045

Raise summer target operating levels by 6” (RO-02B)

Evaluate Impacts of

Change

Modify CRA (if needed)

Semi-Monthly LIP Stage Lookup (LP-03) Operations

Change


Master Plan Status

• Final report to be released May 9, 2014

• 25 Results and Recommendations

• Recommends actions to extend safe yield into next century

• Next phases

– Increase awareness and support

– Expand to water quality issues

– Future updates and plan adjustments

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Questions?

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