Martin Rule Curve Study

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Martin Rule Curve Study

• Ashley McVicar, APC
• Maurice James, Water Resources Consulting LLC

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Martin Rule Curve Study

• Design Flood Study Approach
• Determine flood to model for the 100 year design
  flood
• Replicate operations for the actual flood event
  in an operation spreadsheet
• Model looked at both change in inflow and
  elevation to determine number of gates to open
  limited by 2 an hour
• Compare Results

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Martin Rule Curve Study

• APC Flood Frequency Analysis
• Model developed by US Army Corps of Engineers
  Hydrologic Engineering Center in Davis, CA
• Utilizes the Corps 1939-2001 unimpaired flow
  database created as part of the ACT Comprehensive
  Study
• Submitted to the COE by APC in November 2005

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Martin Rule Curve Study

• Martin flow
• 100 yr flow unregulated 130,000 cfs-days
• March 1990 flow unregulated 125,019 cfs-days
  (96 of 100 year flood)
• March 1990 inflow regulated used in Martin Rule
  Curve evaluation (with Harris and Martin in
  place) 92,307 cfs-days (71 of 100 year
  unregulated flood)

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Current Martin Flood Control Guidelines
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Martin Rule Curve Study

• General Assumptions
• Martin Turbine Capacity 16500 (based on
  observed data from recent past events)
• Yates Turbine Capacity 12400
• Thurlow Turbine Capacity 13200
• 20 lift gates
• 6 alternate (based on opening schedule)
• 11 adjacent
• Assumed we would not use last 3 gates as they
  flood out the powerhouse
• Ability to open 2 spillway gates an hour to be
  conservative

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Martin Rule Curve Study

• Design Flood Evaluation
• Operational criteria set forth in model
  accurately replicated historical conditions

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Martin Rule Curve Study

• Evaluation of Winter Pool of 480 vs. 483
• Used current operational criteria set forth by
  March 1990 flood historical operations and began
  pool at both 480 and 483
• No operational criteria was changed

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JAN FEB MAR
APR MAY JUN
JUL AUG SEP
OCT NOV DEC
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Martin Rule Curve Study

• Elevation 480 vs 483 Results
• Martin pool kept below top of easement elevation
  490 for both
• Beginning winter pool elevation of 483 results
  in earlier releases as well as approximately
  25-30k higher discharge during the peak
• Results routed with HEC-RAS model downstream to
  determine effects

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Martin Rule Curve Study

• Results
• Elevations downstream result in a 1 3 higher
  elevation downstream to Alabama River.
• Corps of Engineers uses FEMAs requirement of no
  increase of peak elevation downstream
• FERC defers to the Corps for flood analysis
• FERC would require a full analysis of impacts of
  proposed vs. current operation including
• Environmental
• Erosion
• etc

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Martin Rule Curve Study

• Further Study during Relicensing Required
• Look at different operational plans
• Pass of inflow in zones
• Open gates based on a lower starting elevation
• Look at different winter pool elevation and/or
  shape of Rule Curve
• 484
• Change in summer pool duration
• Further evaluate downstream flood environmental
  impacts and present these effects and any
  mitigation to FERC
• FERC will then evaluate and balance the proposal