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Martin Rule Curve Study
Ashley McVicar, APC
Maurice James, Water Resources Consulting LLC
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
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
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)
Wadley Annual Peaks
0%
5%
10%
15%
20%
25%
30%
1 2 3 4 5 6 7 8 9 10 11 12
Month
Per
cen
t
81 Years of Record
EL 480 ft.
EL 490 ft.
72%
Current Martin Flood Control Guidelines
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
Martin Reservoir Model Calibration
-
20,000
40,000
60,000
80,000
100,000
120,000
140,000
3/15 3/16 3/17 3/18 3/19 3/20 3/21 3/22 3/23 3/24
Date
Dis
char
ge
cfs
483.0
484.0
485.0
486.0
487.0
488.0
489.0
490.0
Ele
vati
on
ft.
(M
arti
n D
atu
m)
Model Discharge
Actual Discharge
Inflow
Model Elevation
Actual Elevation
Martin Rule Curve Study
• Design Flood Evaluation– Operational criteria set forth in model
accurately replicated historical conditions
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
Martin Reservoir
475
477
479
481
483
485
487
489
491
493
495
Elev
atio
n (M
artin
Dat
um)
JAN FEB MAR APR MAY JUN JUL AUG SEP OCT NOV DEC
Martin Reservoir 480 vs. 483 Model Simulation
-
20,000
40,000
60,000
80,000
100,000
120,000
140,000
15 16 17 18 19 20 21 22 23 24
Date
Dis
char
ge
cfs
478
480
482
484
486
488
490
492
Ele
vati
on
ft.
(M
arti
n D
atu
m)
480 Discharge
483 Discharge
Inflow
480 Elevation
483 Elevation
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
Tallapoosa Profile
150
155
160
165
170
175
180
185
190
195
200
205
210
215
220
0 5 10 15 20 25 30 35 40 45 50 55
Tallapoosa River Mile
Max
imu
m E
leva
tio
n f
t. m
sl Initial Pool-480
Initial Pool-483Montgomery Water
Works gage
Milestead gage
Tallassee gage
Alabama River Thurlow Dam
Martin Rule Curve Study
• Results– Elevations downstream result in a 1’ – 3’ higher
elevation downstream to Alabama River.– Corps of Engineers uses FEMA’s 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
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