HomeMy WebLinkAboutWater_Supply_Proposal_ComparisonsHow to Compare Alternatives from a Water
Supply Viewpoint
July 16, 2013
Ecological Flow Science Advisory Board
Tom Fransen
Division of Water Resources
NC Department of Environment and Natural Resources
Procedure to compare alternatives from
a water users viewpoint.
How is DWR going to use an EFSAB
recommendation.
Presentation Outline
The water users prospective is not part
of the EFSAB’s charge.
The water users prospective is part of
DWR’s implementation.
What is a reasonable approach to compare
alternatives from a water users viewpoint?
We looked at 3 alternative approaches.
If requested by the EFSAB we will add
other alternatives.
How much water needs to remain in the river
to protect ecological integrity and still have
adequate water available for reasonable use?
1.Maximum withdrawal – SEPA
minimum criteria, 20% 7Q10.
2.Flow-By – DWR’s 80% Flow-By
3.Minimum Flow – Modified South
Carolina minimum flows.
3 Alternative Approaches
For the different alternatives determine:
1.Worse Case average daily demand (ADD)
•Analysis assumed a run-of-river intake based
on the lowest flow for the period-of-record
(POR). Assumed a 1.35 peaking factor and
32.5% mandatory drought conservation.
2.Maximum Pumping
•Maximum pumping volume with a maximum
pumping limit of 75% of the mean annual
flow.
Analysis Approach
Example Hydrograph
Slide - 6
ADD Summary
SEPA Minimum
Criteria
20% 7Q10
80% Flow-By Approach
Maximum withdrawal set at
20% POR Minimum
80% Flow-By Approach
Maximum withdrawal set at
10th Percentile
Gage Name Physiographic Region ADD
mgd
ADD
mgd
ADD
mgd
Roaring River near Roaring River Mountain Streams 5.14 1.84 9.93
Linville River at Nebo Mountain Streams 2.40 1.13 5.39
South Fork New River at Jefferson Mountain Streams 14.54 9.22 23.69
Mills River at Mills River Mountain Streams 4.04 2.55 7.66
French Broad River at Marshall Mountain Streams 66.55 27.66 122.99
East Fork Pigeon River near Canton Mountain Streams 2.46 1.56 4.96
Little Tennessee River at Needmore Mountain Streams 10.16 5.25 17.73
Dan River near Wentworth Piedmont Streams 24.24 8.94 55.46
Tar River at US401 at Louisburg Piedmont Streams 0.95 0.30 4.68
Deep River at Ramseur Piedmont Streams 1.81 0.10 5.25
Cape Fear River at Lillington - POR Piedmont Streams 14.66 1.56 57.03
Cape Fear River at Lillington - Pre-Impoundment Piedmont Streams 10.67 1.56 44.83
Cape Fear River at Lillington - Post-Impoundment Piedmont Streams 48.67 21.99 80.29
Mitchell River near State Road Piedmont Streams 4.04 1.99 7.52
Fisher River at Copeland Piedmont Streams 4.07 1.56 9.22
Ararat River at Ararat Piedmont Streams 7.03 1.84 17.02
Yadkin River at Yadkin College Piedmont Streams 82.69 33.48 163.13
Rocky River near Norwood Piedmont Streams 6.63 2.70 14.89
First Broad River near Casar Piedmont Streams 2.07 0.55 3.97
Tar River at Tarboro Upper Coastal Plain Streams 12.14 3.97 36.19
Neuse River at Goldsboro Upper Coastal Plain Streams 20.43 11.06 53.34
Contentnea Creek at Hookerton Upper Coastal Plain Streams 4.05 1.99 12.06
Black River near Tomahawk Upper Coastal Plain Streams 3.26 0.99 14.19
Northeast Cape Fear River near Chinquapin Upper Coastal Plain Streams 1.62 0.61 7.94
Lumber River at Boardman Upper Coastal Plain Streams 15.70 5.96 39.58
Average 14.80 6.01 32.76
Percent Difference
Based on 20% 7Q10 -59.36% 121.32%
Minimum 0.95 0.10 3.97
Maximum 82.69 33.48 163.13
Modified SC Summary
Based on Annual Mean
Approach
Modified SC Minimums
Based on Monthly Means
Approach
Modified SC Minimums
Gage Name Physiographic Region
Days Below
Minimum,
Percent
Number of
Periods,
Periods/Year
Days Below
Minimum,
Percent
Number of
Periods,
Periods/Year
Roaring River near Roaring River Mountain Streams 3.5% 1.61 3.9% 1.95
Linville River at Nebo Mountain Streams 11.4% 5.40 10.6% 5.36
South Fork New River at Jefferson Mountain Streams 2.7% 1.71 2.4% 1.84
Mills River at Mills River Mountain Streams 6.8% 2.79 5.6% 2.92
French Broad River at Marshall Mountain Streams 4.2% 1.77 3.5% 1.57
East Fork Pigeon River near Canton Mountain Streams 10.6% 4.91 9.3% 4.10
Little Tennessee River at Needmore Mountain Streams 4.7% 2.27 3.4% 1.78
Dan River near Wentworth Piedmont Streams 2.6% 1.59 3.4% 2.55
Tar River at US401 at Louisburg Piedmont Streams 37.3% 11.31 32.4% 13.11
Deep River at Ramseur Piedmont Streams 31.3% 21.99 26.9% 22.24
Cape Fear River at Lillington - POR Piedmont Streams 31.6% 15.35 24.2% 14.23
Cape Fear River at Lillington - Pre-Impoundment Piedmont Streams 31.3% 16.48 27.5% 18.19
Cape Fear River at Lillington - Post-Impoundment Piedmont Streams 27.7% 14.36 18.7% 9.55
Mitchell River near State Road Piedmont Streams 1.1% 0.75 1.7% 1.12
Fisher River at Copeland Piedmont Streams 2.2% 1.33 2.6% 1.82
Ararat River at Ararat Piedmont Streams 1.7% 1.44 2.3% 1.85
Yadkin River at Yadkin College Piedmont Streams 1.3% 0.80 1.9% 1.28
Rocky River near Norwood Piedmont Streams 47.1% 16.85 41.4% 18.09
First Broad River near Casar Piedmont Streams 4.3% 1.97 5.2% 2.61
Tar River at Tarboro Upper Coastal Plain Streams 38.0% 8.50 34.0% 10.00
Neuse River at Goldsboro Upper Coastal Plain Streams 35.3% 9.23 30.5% 10.35
Contentnea Creek at Hookerton Upper Coastal Plain Streams 37.6% 8.20 34.6% 9.22
Black River near Tomahawk Upper Coastal Plain Streams 31.4% 8.50 28.9% 9.28
Northeast Cape Fear River near Chinquapin Upper Coastal Plain Streams 39.5% 8.25 38.9% 9.51
Lumber River at Boardman Upper Coastal Plain Streams 22.6% 4.29 17.9% 4.03
Average 18.7% 6.87 16.5% 7.14
Percent Difference Based on 20% 7Q10
Minimum 1.1% 0.75 1.7% 1.12
Maximum 47.1% 21.99 41.4% 22.24
Maximum Pumping
Slide - 9
Maximum Pumping Analysis
Pumping maximum limited to 75.0% mean annual flow
Gage Name Physiographic Region
SEPA Minimum Criteria 20% 7Q10
ADD, mgd
80% Flow-By
Approach
ADD, mgd
Minimum Flows Based on Annual Mean
ADD, mgd
Minimum Flows Based on Monthly Means
ADD, mgd
Roaring River near Roaring River Mountain Streams 5.14 22.14 53.05 52.55
Linville River at Nebo Mountain Streams 2.40 17.22 36.25 35.52
South Fork New River at Jefferson Mountain Streams 14.54 53.06 131.01 129.66
Mills River at Mills River Mountain Streams 4.04 21.03 49.21 48.70
French Broad River at Marshall Mountain Streams 66.55 306.04 725.32 717.98
East Fork Pigeon River near Canton Mountain Streams 2.46 16.92 36.14 35.51
Little Tennessee River at Needmore Mountain Streams 10.16 47.76 112.55 112.12
Dan River near Wentworth Piedmont Streams 24.24 138.18 329.46 322.04
Tar River at US401 at Louisburg Piedmont Streams 0.95 43.27 65.61 62.14
Deep River at Ramseur Piedmont Streams Min Flow > 20% 7Q10 34.26 55.44 52.48
Cape Fear River at Lillington - POR Piedmont Streams Min Flow > 20% 7Q10 361.03 556.07 539.15
Cape Fear River at Lillington - Pre-
Impoundment Piedmont Streams Min Flow > 20% 7Q10 351.53 558.79 539.84
Cape Fear River at Lillington - Post-
Impoundment Piedmont Streams 48.67 359.05 533.70 521.04
Mitchell River near State Road Piedmont Streams 4.04 15.29 40.44 39.91
Fisher River at Copeland Piedmont Streams 4.07 21.29 53.56 52.56
Ararat River at Ararat Piedmont Streams 7.03 37.58 95.89 94.37
Yadkin River at Yadkin College Piedmont Streams 82.69 361.80 906.57 890.19
Rocky River near Norwood Piedmont Streams 6.63 121.16 148.63 137.18
First Broad River near Casar Piedmont Streams 2.07 10.13 24.37 23.90
Tar River at Tarboro Upper Coastal Plain Streams 12.14 259.47 332.06 329.37
Neuse River at Goldsboro Upper Coastal Plain Streams 20.43 299.56 407.28 406.03
Contentnea Creek at Hookerton Upper Coastal Plain Streams 4.05 93.20 125.11 124.89
Black River near Tomahawk Upper Coastal Plain Streams 3.26 93.91 142.68 143.34
Northeast Cape Fear River near Chinquapin Upper Coastal Plain Streams 1.62 82.88 105.67 105.31
Lumber River at Boardman Upper Coastal Plain Streams 15.70 161.33 281.41 282.05
Average 15.59 133.16 236.25 231.91
Percent Difference
Based on 20% 7Q10 5.30% 799.71% 1496.20% 1466.90%
Minimum 0.95 10.13 24.37 23.90
Maximum 82.69 361.80 906.57 890.19
Slide - 10
Slide - 11
Planning tool
Will not override existing permits, such as FERC
license.
Will not replace site specific studies.
Will not change the SEPA minimum criteria – 20%
7Q10
During the planning process if ecologic
integrity is determined or projected to be
adversely impacted, we will flag the river
reach for additional studies.
How will DWR implement an
EFSAB recommendation?
Using the EMC approved river basin model
compare the current conditions scenario
(SIMBASE) with a future conditions
alternative.
Use permitted flow requirements.
For nodes with no permit requirements.
Create an 80% BASELINE using SIMBASE
and compare future conditions scenarios to
the baseline. When a scenario flow is below
the BASELINE that represents a potential
adverse ecological impact.
Example Using the 80% Flow-By
For illustration purposes only.
Summarize the analysis for both the full
model period-of-record and the IndexB
approach of using the data between 10th and
90th percentiles.
Results interpretation
No Impact (Green) – POR no days with flows <
80%.
Watch (Yellow) – POR of has 1 or more days < 80%
and IndexB has no days < 80%.
Additional Study (Red) - Both the POR and IndexB
have 1 or more days < 80%.
Example Using the 80% Flow-By
For illustration purposes only.
Broad Model Example
Broad River Basin - 2060 Scenario
Baseline - Simbase (Current Conditions)
80% of Flow-By
Full Record
80% of Flow-By
IndexB Approach (10% - 90%)
Arc Node Description of the Node Number of days with potential
adverse impacts
Number of days with potential adverse
impacts
010.020 Lake Summit Release 0 0
020.040 Green River to Lake Adger 0 0
040.050 Lake Adger Release 168 0
050.060 Green River to Ken Miller 168 0
060.100 Green River to Broad Confluence 168 0
070.080 Lake Lure Release 0 0
080.090 Upper Broad 30 0
090.100 Upper Broad to Broad Confluence 24 0
100.170 Broad River to Foresty City Intake 4 0
150.190 2nd Broad 18 0
190.200 2nd Broad Cliffside 0 0
170.180 Forest City Intake (2nd Broad) 4 0
180.200 Upper Cliffside 4 0
200.220 2nd Broad Confluence 0 0
220.250 Cliffside Dam Release 25 0
250.260 Boiling Spring Gage 4 0
410.415
Cleveland Intake Cleveland Intake 159 0
415.420 Lawndale Gage 116 0
420.440 Shelby Intake (1st Broad) 131 0
440.450 Stice Shoals Dam Release 0 0
450.500 First Broad Confluence 0 0
500.550 Lower Broad 4 0
550.700 Gaston Shoals Dam Release 104 2
600.610
Kings Mnt Res Kings Mountain Reservoir Release 290 282
610.650 Kings Mountain WTP Discharge 163 154
650.700 Buffallo Creek Confluence 50 43
700.999 Gaffney Gage 26 0
Number of no impacts nodes 7
Number of watch nodes 16
Number of additional study nodes 4
Questions
Slide - 16
Comparison of
Natural vs. Current Conditions (Simbase)
PHABSIM & 80% Flow-By
June 18, 2013
Ecological Flow Science Advisory Board
Fred Tarver & Tom Fransen
Division of Water Resources
NC Department of Environment and Natural Resources
Broad River Basin Model
Slide - 18
Kings Mnt
80% Flow-By
& PHABSIM
PHABSIM (Shallow)
Arc 600.100 Kings Mnt Reservoir
Slide - 19
0
10
20
30
40
50
60
Flow Scenario
Pe
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% of 11 Shallow or Bug (E-P-T) Guilds/Orders with Less Than 80% of
Index B Values
SIM/UNREG SIM60/UNREG SIM60/SIM
Seasonal not shown all values are 0.
PHABSIM (Deep)
Arc 600.100 Kings Mnt Reservoir
Slide - 20
0
10
20
30
40
50
60
Flow Scenario
Pe
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% of 8 Deep & Golden Redhorse Guilds
with Less Than 80% of Index B Values
SIM/UNREG SIM60/UNREG SIM60/SIM
0
10
20
30
40
50
60
Pe
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% of 8 Deep & Golden Redhorse Guilds with Less Than 80% of Index B Values By Season
Majority of reductions in habitat are associated with “Deep
Fast” guilds where half or nearly half of months fall below 80%
threshold.
“Deep Slow” guilds have 1 or 2 month breaches of 80%
threshold.
Another Deep species (Golden Redhorse Juvenile), with nearly
half of months below threshold, had habitat values <500 by
month.
The Simbase and 2060 projection include WWTP return flows,
which tend to offset dam alterations.
Seasonal calculations (Summer) tended to exclude breaches
for marginal months when using Index B (mean of habitat
events between 10 and 90% exceedence).
PHABSIM – Model Scenario Details
Most of the impacts occurred between
Natural and Current Conditions.
Little to no addition impacts between
Current Conditions and projected 2060
scenario conditions.
PHABSIM - Comments
80% Flow-By Comparison
Broad River Basin - Simbase (Current
Conditions) Scenario
Baseline - Natural Flows
Broad River Basin - 2060 Scenario
Baseline - Natural Flows
Broad River Basin - 2060 Scenario
Baseline - Simbase (Current Conditions)
80% of Flow-By
IndexB Approach (10% - 90%)
80% of Flow-By
IndexB Approach (10% - 90%)
80% of Flow-By
IndexB Approach (10% - 90%)
Arc Node
Number of days with
potential adverse
impacts
Percent of
days
Number of days with
potential adverse
impacts
Percent of days Number of days with
potential adverse impacts Percent of days
010.020 0 0.000% 0 0.000% 0 0.000%
020.040 0 0.000% 0 0.000% 0 0.000%
040.050 0 0.000% 0 0.000% 0 0.000%
050.060 0 0.000% 0 0.000% 0 0.000%
060.100 0 0.000% 0 0.000% 0 0.000%
070.080 0 0.000% 0 0.000% 0 0.000%
080.090 0 0.000% 0 0.000% 0 0.000%
090.100 0 0.000% 0 0.000% 0 0.000%
100.170 0 0.000% 0 0.000% 0 0.000%
150.190 0 0.000% 0 0.000% 0 0.000%
190.200 0 0.000% 0 0.000% 0 0.000%
170.180 0 0.000% 0 0.000% 0 0.000%
180.200 0 0.000% 0 0.000% 0 0.000%
200.220 0 0.000% 0 0.000% 0 0.000%
220.250 0 0.000% 0 0.000% 0 0.000%
250.260 0 0.000% 0 0.000% 0 0.000%
410.415
Cleveland Intake 0 0.000% 0 0.000% 0 0.000%
415.420 0 0.000% 0 0.000% 0 0.000%
420.440 0 0.000% 0 0.000% 0 0.000%
440.450 0 0.000% 0 0.000% 0 0.000%
450.500 0 0.000% 0 0.000% 0 0.000%
500.550 0 0.000% 0 0.000% 0 0.000%
550.700 35 0.148% 55 0.233% 2 0.008%
600.610
Kings Mnt Res 8,044 34.118% 9,763 41.409% 282 1.241%
610.650 4,807 20.389% 4,845 20.550% 154 0.656%
650.700 178 0.755% 192 0.814% 43 0.182%
700.999 22 0.093% 32 0.136% 0 0.000%
Nodes Potential Impact
Slide - 24
Broad River Basin - Simbase (Current Conditions) Scenario
Baseline - Natural Flows
Kings Mountain Reservoir (600.610)
Full Hydrograph
Natural Flows 80% Natural Flows Simbase
0.500% 1.97 1.58 12.00
1.000% 4.45 3.56 12.00
2.000% 8.15 6.52 12.00
5.000% 14.67 11.74 12.00
10.000% 21.36 17.09 12.00
15.000% 26.15 20.92 14.79
20.000% 30.16 24.13 20.25
25.000% 34.07 27.26 25.03
30.000% 37.96 30.37 29.26
35.000% 41.30 33.04 33.70
40.000% 45.49 36.40 38.26
45.000% 49.67 39.74 42.85
50.000% 54.57 43.66 48.26
55.000% 59.47 47.58 53.81
60.000% 64.62 51.70 60.19
65.000% 71.17 56.94 67.07
70.000% 77.99 62.39 74.76
75.000% 86.16 68.92 83.96
80.000% 96.69 77.36 96.45
85.000% 113.17 90.54 115.94
90.000% 141.36 113.09 148.30
95.000% 217.60 174.08 234.08
98.000% 419.13 335.30 461.28
99.000% 657.43 525.94 710.88
99.500% 966.98 773.59 1,035.70
99.997% 4,242.06 3,393.65 4,448.70
Month/Period
Number of Days
Flows < 80%
% of Days
Flows < 80%
Average
Deficit, cfs
Average
Deficit, % Diff
1 96 4.647% 0.26 0.804%
2 109 5.867% 0.24 0.754%
3 106 5.389% 0.34 0.813%
4 506 23.947% 0.77 1.836%
5 1,015 45.011% 1.58 4.646%
6 1,176 58.247% 2.49 7.148%
7 1,189 61.992% 3.31 9.986%
8 1,184 66.071% 3.48 10.699%
9 1,121 67.612% 2.73 9.119%
10 948 52.872% 1.69 5.905%
11 472 23.529% 0.87 2.638%
12 122 5.722% 0.37 1.013%
Spring (4-6) 2,697 42.226% 1.60 4.507%
Summer (7-9) 3,494 65.089% 3.19 9.956%
Fall (10-11) 1,420 37.378% 1.26 4.180%
Winter (12-3) 433 5.397% 0.33 0.902%
P-O-R 8,044 34.118% 1.46 4.450%
Broad River Basin - Simbase (Current Conditions) Scenario
Baseline - Natural Flows
Kings Mountain Reservoir (600.610)
IndexB Approach (10% - 90%)
Most of the impacts occurred between
Natural and Current Conditions.
Measures small addition impacts
between Current Conditions and
projected 2060 scenario conditions.
IndexB approach 85% (22 out of 27) no
potential impact.
80% Flow-By - Comments
Questions
Slide - 28
80% Flow-By
vs.
20% 7Q10
5-13-2013
Ecological Flow Science Advisory Board
Tom Fransen
Division of Water Resources
NC Department of Environment and Natural Resources
DWR is not assuming that the “80%
Flow-By” approach will be the SAB’s
final recommendation.
Goal of analysis is to test a potential
ecologic integrity planning criteria.
The purpose of this presentation is to
provide an example of “one” approach
that could be used to implement a
Flow-By approach.
Disclaimer
20% 7Q10 is a SEPA minimum criteria
for additional study.
If the maximum instantaneous with is less
than 20% 7Q10 then no additional analysis
is needed.
20% 7Q10 has frequency been
misapplied as the safe yield.
How is 20% 7Q10 used?
Best application is a single isolated run-of-
river withdrawal.
Does not work for withdrawals from
reservoirs.
How to apply to multiple near by
withdrawals?
Does not provide a metric to assess the
accumulative upstream impacts.
Only applies to run-of-river nodes with a
withdrawal.
Implementation Problem With
20% 7Q10
Need an approach that will work for
single, multiple near-by, and reservoir
withdrawals.
Needs to be able to assess the
accumulative upstream impacts at all
flow nodes, work at nodes with or
without withdrawals.
Trial Implementation of 80%
Flow-By
Starting Point
SL 2010-143 Definitions
"Ecological integrity" means the ability of an aquatic system to support and
maintain a balanced, integrated, adaptive community of organisms having a
species composition, diversity, and functional organization comparable to
prevailing ecological conditions and, when subject to disruption, to recover
and continue to provide the natural goods and services that normally accrue from
the system.
"Prevailing ecological conditions" means the ecological conditions
determined by reference to the applicable period of record of the United States
Geological Survey stream gauge data, including data reflecting the ecological
conditions that exist after the construction and operation of existing flow
modification devices, such as dams, but excluding data collected when
stream flow is temporarily affected by in-stream construction activity.
Analysis Assumption
Assume the SIMBASE modeling scenario represents “Prevailing ecological
conditions”. SIMBASE is the model scenario that represents current conditions,
withdrawals, discharges, reservoir operations, drought plans, etc.
Slide - 34
Create an 80% BASELINE using SIMBASE and
compare scenarios to the baseline. When a scenario
flow is below the BASELINE, that represents a
potential adverse ecological impact.
Analysis steps:
1.For each day (29,493 days)
BASELINE = 80% * SIMBASE (outflow from the arc)
2.Compare each day (29,493 days)
IF scenario < BASELINE then that days is a
potential adverse ecological impact day.
3.Looking for guidance on how to assess if a node is
adversely impacted based on number of days, time
of year, etc.
80% Flow-By Analysis Approach
80% Flow-By Example
0
10
20
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50
60
70
80
90
100
8/1/2002 8/8/2002 8/15/2002 8/22/2002 8/29/2002 9/5/2002 9/12/2002
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Cleveland County Intake
2060 Scenario
SIMBASE
80%SIMBASE
Potential Adverse Impact
No Impact
No impact if the green line
is above the red line.
Potential adverse impact
when the green line is below
the red line.
Broad River Basin
Only certified model
One of the smaller and simpler basins.
Has a mix of withdrawals both run-of-river
and reservoir.
Analyzed 27 river nodes, this include the
reservoir release nodes with a modeling
record of 1/1/1930 to 12/31/2009.
Trial Balloon
Broad River Basin Model
Slide - 38
Gaffney Gage
Kings Mnt
Cleveland
Slide - 39
1
10
100
1,000
10,000
100,000
1/1/1930 1/1/1940 1/1/1950 1/1/1960 1/1/1970 1/1/1980 1/1/1990 1/1/2000
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Cleveland County Intake
2060 Scenario
SIMBASE
80% SIMBASE
2060
No impact if the green line
is above the red line.
Potential adverse impact
when the green line is below
the red line.
Slide - 40
1
10
100
1,000
10,000
1/1/1930 1/1/1940 1/1/1950 1/1/1960 1/1/1970 1/1/1980 1/1/1990 1/1/2000
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Kings Mnt Reservoir Release
2060 Scenario
SIMBASE
80% SIMBASE
2060
No impact if the green line
is above the red line.
Potential adverse impact
when the green line is below
the red line.
Slide - 41
1
10
100
1,000
10,000
100,000
1/1/1930 1/1/1940 1/1/1950 1/1/1960 1/1/1970 1/1/1980 1/1/1990 1/1/2000
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Gaffney Gage
2060 Scenario
SIMBASE
80% SIMBASE
2060
No impact if the green line
is above the red line.
Potential adverse impact
when the green line is below
the red line.
80% of Flow-By
Arc Node Description of the Node Number of days with potential
adverse impacts Percent of days
010.020 Lake Summit Release 0 0.00%
020.040 Green River to Lake Adger 0 0.00%
040.050 Lake Adger Release 168 0.57%
050.060 Green River to Ken Miller 168 0.57%
060.100 Green River to Broad Confluence 168 0.57%
070.080 Lake Lure Release 0 0.00%
080.090 Upper Broad 30 0.10%
090.100 Upper Broad to Broad Confluence 24 0.08%
100.170 Broad River to Forest City Intake 4 0.01%
150.190 2nd Broad 18 0.06%
190.200 2nd Broad Cliffside 0 0.00%
170.180 Forest City Intake (2nd Broad) 4 0.01%
180.200 Upper Cliffside 4 0.01%
200.220 2nd Broad Confluence 0 0.00%
220.250 Cliffside Dam Release 25 0.08%
250.260 Boiling Spring Gage 4 0.01%
410.415 Cleveland Intake 159 0.54%
415.420 Lawndale Gage 116 0.39%
420.440 Shelby Intake (1st Broad) 131 0.44%
440.450 Gaston Shoals Dam Release 0 0.00%
450.500 First Broad Confluence 0 0.00%
500.550 Lower Broad 4 0.01%
550.700 Gaston Shoals Dam Release 104 0.35%
600.610 Kings Mountain Reservoir Release 290 0.98%
610.650 Kings Mountain WTP Discharge 163 0.55%
650.700 Buffalo Creek Confluence 50 0.17%
700.999 Gaffney Gage 26 0.09%
Broad River Basin - 2060 Scenario Node Summary
74% of the nodes (20 out 27) with 1 or more days with potential impacts.
Potential impacts occur less than 1% of the time.
Broad River Basin - 2060 Scenario
80% of Flow-By Summary
Days Potential Impact Difference (2060-80%SIMBASE), cfs
Arc
Node Description of the Node Number of days Percent of
days Minimum Average Median Maximum
410.415 Cleveland Intake 159 0.54% 0.00 0.01 0.00 4.64
600.610 Kings Mountain Reservoir
Release 290 0.98% 0 0.11 0 242.83
700.999 Gaffney Gage 26 0.09% 0.00 0.01 0.00 32.61
Average of the 27 Nodes 61 0.21%
Difference (2060-80%SIMBASE), cfs
Minimum Average Median Maximum
410.415 Cleveland Intake 0.00% 0.08% 0.00% 80.00%
600.610 Kings Mountain Reservoir
Release 0.00% 0.20% 0.00% 72.59%
700.999 Gaffney Gage 0.00% 0.01% 0.00% 16.46%
Slide - 44
-80%
-70%
-60%
-50%
-40%
-30%
-20%
-10%
0%
10%
20%
30%
40%
50%
60%
70%
80%-5.00
-4.00
-3.00
-2.00
-1.00
0.00
1.00
2.00
3.00
4.00
5.00
1/1930 1/1940 1/1950 1/1960 1/1970 1/1980 1/1990 1/2000
De
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-20
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,
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Time, days
Cleveland County Intake- 2060
80% Flow-By Deficit, cfs
Slide - 45
-75%
-65%
-55%
-45%
-35%
-25%
-15%
-5%
5%
15%
25%
35%
45%
55%
65%
75%-250
-200
-150
-100
-50
0
50
100
150
200
250
1/1930 1/1940 1/1950 1/1960 1/1970 1/1980 1/1990 1/2000
De
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,
c
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Time, days
Kings Mnt Reservoir Release - 2060
80% Flow-By Deficit, cfs
80% Flow-By Deficit, %
Difference
Slide - 46
-20%
-10%
0%
10%
20%-35.00
-30.00
-25.00
-20.00
-15.00
-10.00
-5.00
0.00
5.00
10.00
15.00
20.00
25.00
30.00
35.00
1/1930 1/1940 1/1950 1/1960 1/1970 1/1980 1/1990 1/2000
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Time, days
Gaffney Gage - 2060
80% Flow-By Deficit, cfs
Non-Exceedence Cleveland Intake
cfs
Kings Mountain Reservoir Release
cfs
Gaffney Gage
cfs
Percent 80%SIMBASE 2060 80%SIMBASE 2060 80%SIMBASE 2060
0.003% 2.81 0.00 9.60 12.00 50.05 39.76
0.500% 23.80 23.44 9.60 12.00 278.08 323.90
1.000% 30.46 32.06 9.60 12.00 364.80 442.81
2.000% 38.46 42.13 9.60 12.00 396.62 485.32
5.000% 50.28 56.89 9.60 12.00 561.44 682.26
10.000% 66.46 77.13 9.60 12.00 720.60 876.10
15.000% 78.07 91.89 11.84 12.14 831.03 1,015.71
20.000% 87.00 102.98 16.20 18.27 933.17 1,144.17
25.000% 94.86 112.89 20.02 23.12 1,025.51 1,259.31
30.000% 103.01 123.14 23.41 27.49 1,115.89 1,373.37
35.000% 112.13 134.44 26.96 32.15 1,207.28 1,487.16
40.000% 121.40 146.09 30.60 36.56 1,292.03 1,593.01
45.000% 130.48 157.30 34.28 41.23 1,385.76 1,709.70
50.000% 140.08 169.34 38.61 46.72 1,487.14 1,837.53
55.000% 150.48 182.30 43.05 52.22 1,598.96 1,977.31
60.000% 162.19 197.09 48.16 58.59 1,719.80 2,128.53
65.000% 174.99 213.09 53.65 65.52 1,843.28 2,283.46
70.000% 190.48 232.28 59.81 73.28 1,996.54 2,474.56
75.000% 209.73 256.98 67.17 82.35 2,183.80 2,707.04
80.000% 235.79 289.23 77.16 94.89 2,432.98 3,019.67
85.000% 272.83 335.27 92.75 114.22 2,790.52 3,466.91
90.000% 334.48 412.28 118.64 146.41 3,393.62 4,220.36
95.000% 497.03 615.52 187.26 231.59 4,886.97 6,088.46
98.000% 868.27 1,080.09 369.03 458.72 7,920.52 9,881.02
99.000% 1,339.84 1,669.31 568.70 709.43 11,190.51 13,968.40
99.500% 1,938.71 2,417.33 828.56 1,034.32 14,958.05 18,676.93
99.997% 14,402.30 17,996.62 3,558.96 4,446.98 43,746.91 54,661.96
Broad River Basin - 2060 Scenario - 80% of Flow-By
Frequency Analysis
Red cells are 2060 flows a potential adverse impact.
How do we implement your
recommendation?
If a flow-by approach is used, is the
analysis on the right path?
Is SIMBASE the correct starting point?
Do all flows need to be ≥ 80% of
SIMBASE?
Are certain times of the year or specific
flow ranges of more importance?
?
We Need Help With -
Questions
80% flow-by is a trial balloon DWR is open willing
to consider all recommendations from the SAB,
including variations on the 80% theme.
Contact Information
Tom Fransen, Deputy Director
Tom.Fransen@ncdenr.gov
919-707-9015
Slide - 49