20070295 Ver 6_3.01 Pre Hydrology Inputs_20191220

Holding Village - North Lake
RAP-19000
HYDROLOGY INPUT SUMMARY -
PRE -DEVELOPMENT HYDROLOGY
Summary of Results
Maria Torres, E.I.
Daniel Gunter
12.16.2019
Sub -basin ID
Drainage Area [acres]
SCS CN
Tc [min]
Impervious
Open
Wooded
Pond
1/8 ac lots
1/4 ac lots
Commercial
Industrial
Total
1 to Lake
11.56
24.48
11.76
12.89
35.91
9.09
1.44
11.12
118.25
81
19.72
1 Bypass
1.63
7.30
2.00
0.00
0.00
0.00
0.00
0.00
10.92
82
9.78
4
0.68
0.41
13.79
0.00
0.00
0.00
0.00
0.00
14.88
59
17.61
5
0.20
9.77
12.73
0.00
0.00
0.00
0.00
0.00
22.70
60
20.54
6
0.00
0.00
2.84
0.00
0.00
0.00
0.00
0.00
2.84
57
15.27
7
0.00
2.04
6.34
0.87
0.00
0.00
0.00
0.00
9.26
62
18.99
Totals =
14.07 44.00 49.47 13.76 35.91 9.09 1.44 11.12
178.86

Holding Village- North Lake PRE -DEVELOPMENT HYDROLOGY Maria Torres, E.I.
RAP-19000 Sub1 to Lake Daniel Gunter
12.16.2019
Soils from WebSoilSurvey are only inclusive of indirectly connected areas
Assume:
HSG
Impervious
Open
Wooded
A
98
39
30
B
98
61
55
C
98
74
70
D
98
80
77
HSG 'A' = 10.6%
HSG'B'= 66.8%
HSG'C'= 0.0%
22.8%
Cover Condition SCS CN Comments
Impervious 98
Open 63 Assume good condition
Wooded 57 Assume good condition
II. PRE -DEVELOPMENT'
A. Onsite Impervious Breakdown
Contributing Area
Area [sfJ
Area ac
Roadwa Area
0
0.00
Driveway/ Parking Lot
0
0.00
Roof
0
0.00
Sidewalk / Patio
0
0.00
Other
0
0.00
Totals
0
0.00
B. Watershed Land Use Breakdown
Contributing Area
SCS CN
Area [sfl
Area acres
Comments
Impervious
98
503,694
11.56
Open
63
1,066,284
24.48
Assume good condition
Wooded
57
512,053
11.76
Assume good condition
Pond
100
561,526
12.89
Residential 1/8 ac
86
1,564,273
35.91
Residential 1/4 ac
76
395,974
9.09
Assume good condition
Commercial
93
62,580
1.44
Assume good condition
Industrial
89
484,466
11.12
TotaIIC area =
118.25 acres
5,150,850 sf
Composite SCS CN =
81
% Impervious =
40.1%

Holding Village- North Lake PRE -DEVELOPMENT HYDROLOGY Maria Torres, E.I.
RAP-19000 Sub1 to Lake Daniel Gunter
12.16.2019
III. TIME OF CONCENTRATION INFORMATI
Time of concentration is calculated using the SCS Segmental Approach (TR-55).
Segment 1: Overland Flow
Length =
Height =
Slope =
Manning's n =
P (2-year/24-hour) =
Segment Time =
Segment 3: Channel Flow
Length =
Height =
Slope =
Manning's n =
Flow Area =
Wetted Perimeter=
Channel Velocity =
Segment Time =
100
ft
3
ft
0.0300
ft/ft
0.24
dense grasses
3.45
inches (Wake Forest, NC)
11.69
minutes
1485
ft
54
ft
0.0364
ft/ft
0.045
natural channel
4.00
sf (assume 2'w x 2'h channel)
6.00
If (assume 2' x 2' channel)
4.82
ft/sec
5.14
minutes
Segment2: Concentrated Flow
Length =
680
ft
Height =
40
ft
Slope =
0.0588
ft/ft
Paved ? =
No
Velocity=
3.91
ft/sec
Segment Time =
2.90
minutes
Time of Concentration = 19.72 minutes
SCS Lag Time = 11.83 minutes (SCS Lag = 0.6* Tc)
Time Increment = 3.43 minutes (= 0.29*SCS Lag)
* CALCULATIONS TAKEN FROM PREVIOUSLY APPROVED DESIGN

Holding Village- North Lake PRE -DEVELOPMENT HYDROLOGY Maria Torres, E.I.
RAP-19000 Sub1 Bypass Daniel Gunter
12.16.2019
Soils from WebSoilSurvey are only inclusive of indirectly connected areas
Assume:
HSG
Impervious
Open
Wooded
A
98
39
30
B
98
61
55
C
98
74
70
D
98
80
77
HSG'A'= 0.0%
HSG'B'= 0.0%
HSG'C'= 0.0%
100.0%
Cover Condition SCS CN
moervious 98
Open 80
Wooded 77
II. PRE-DEVELOPMEM�
A. Onsite Impervious Breakdown
Comments
Assume good condition
Assume Rood condition
Contributing Area
Area [sfJ
Area ac
Roadwa Area
0
0.00
Driveway/ Parking Lot
0
0.00
Roof
0
0.00
Sidewalk / Patio
0
0.00
Other
0
0.00
Totals
0
0.00
B. Watershed Land Use Breakdown
Contributing Area
SCS CN
Area [sfl
Area acres
Comments
Impervious
98
70,794
1.63
Open
80
317,773
7.30
Assume good condition
Wooded
77
87,295
2.00
Assume good condition
Pond
100
0
0.00
Residential 1/8 ac
86
0
0.00
Residential 1/4 ac)
76
0
0.00
Assume good condition
Commercial
93
0
0.00
Assume good condition
Industrial
89
0
0.00
TotaIIC area = 10.92 acres
475,862 sf
Composite SCS CN = 82
% Impervious = 14.9%

Holding Village- North Lake PRE -DEVELOPMENT HYDROLOGY Maria Torres, E.I.
RAP-19000 Sub1 Byposs Daniel Gunter
12.16.2019
III. TIME OF CONCENTRATION INFORMATION
Time of concentration is calculated using the SCS Segmental Approach (TR-55).
.Segment 1: Overland Flow
Length =
100
ft
Height =
7
ft
Slope =
0.0700
ft/ft
Manning's n =
0.24
dense grasses
P (2-year/24-hour) =
3.45
inches (Wake Forest, NC)
Segment Time =
8.33
minutes
Segment 3: Channel Flow
Length =
320
ft
Height =
18
ft
Slope =
0.0563
ft/ft
Manning's n =
0.045
natural channel
Flow Area =
4.00
sf (assume 2'w x 2'h channel)
Wetted Perimeter =
6.00
If (assume 2' x 2' channel)
Channel Velocity =
5.99
ft/sec
Segment Time =
0.89
minutes
.Segment 2: Concentrated Flow
Length =
182
ft
Height =
20
ft
Slope =
0.1099
ft/ft
Paved ? =
No
Velocity=
5.35
ft/sec
Segment Time =
0.57
minutes
Time of Concentration = 9.78 minutes
SCS Lag Time = 5.87 minutes (SCS Lag = 0.6* Tc)
Time Increment = 1.70 minutes (= 0.29*SCS Lag)
* CALCULATIONS TAKEN FROM PREVIOUSLY APPROVED DESIGN

Holding Village- North Lake PRE -DEVELOPMENT HYDROLOGY Maria Torres, E.I.
RAP-19000 Sub4 Daniel Gunter
12.16.2019
Soils from WebSoilSurvey are only inclusive of indirectly connected areas
Assume:
HSG
Impervious
Open
Wooded
A
98
39
30
B
98
61
55
C
98
74
70
D
98
80
77
HSG 'A' = 38.6%
HSG'B'= 0.0%
HSG'C'= 28.6%
32.8%
Cover Condition SCS CN
moervious 98
Open 62
Wooded 57
II. PRE -DEVELOPMENT
A. Onsite Impervious Breakdown
Comments
Assume good condition
Assume Rood condition
Contributing Area
Area [sfJ
Area ac
Roadwa Area
0
0.00
Driveway/ Parking Lot
0
0.00
Roof
0
0.00
Sidewalk / Patio
0
0.00
Other
0
0.00
Totals
0
0.00
B. Watershed Land Use Breakdown
Contributing Area
SCS CN
Area [sfl
Area acres
Comments
Onsite impervious
98
29,550
0.68
Onsite open
62
17,887
0.41
Assume good condition
Onsite wooded
57
600,748
13.79
Assume good condition
Onsite pond
100
0
0.00
Offsite impervious
98
0
0.00
Offsite open
62
0
0.00
Assume good condition
Offsite wooded
57
0
0.00
Assume good condition
Offsite pond
100
0
0.00
TotaIIC area = 14.88 acres
648,185 sf
Composite SCS CN = 59
% Impervious = 4.6%

Holding Village- North Lake PRE -DEVELOPMENT HYDROLOGY Maria Torres, E.I.
RAP-19000 Sub4 Daniel Gunter
12.16.2019
III. TIME OF CONCENTRATION INFORMATI
Time of concentration is calculated using the SCS Segmental Approach (TR-55).
Segment 1: Overland Flow
Length =
100
ft
Top Elev =
333.00
ft
BotElev =
328.00
ft
Height =
5
ft
Slope =
0.0500
ft/ft
Manning's n =
0.40
wooded
P (2-year/24-hour) =
3.45
inches (Wake Forest, NC)
Segment Time =
14.34
minutes
Segment 3: Channel Flow
Length =
367
ft
Top Elev =
258.00
BotElev =
241.00
Height =
17
ft
Slope =
0.0463
ft/ft
Manning's n =
0.045
natural channel
Flow Area =
4.00
sf (assume 2'w x 2'h channel)
Wetted Perimeter =
6.00
If (assume 2' x 2' channel)
Channel Velocity =
5.44
ft/sec
Segment Time =
1.12
minutes
Segment2: Concentrated Flow
Length =
672
ft
Top Elev =
328.00
ft
BotElev =
258.00
ft
Height =
70
ft
Slope =
0.1042
ft/ft
Paved ? =
No
Velocity=
5.21
ft/sec
Segment Time =
2.15
minutes
Time of Concentration = 17.61 minutes
SCS Lag Time = 10.57 minutes (SCS Lag = 0.6* Tc)
Time Increment = 3.06 minutes (= 0.29*SCS Lag)

Holding Village- North Lake PRE -DEVELOPMENT HYDROLOGY Maria Torres, E.I.
RAP-19000 Sub5 Daniel Gunter
12.16.2019
I. SCS CURVE NUMBERS
Soils from WebSoilSurvey are only inclusive of indirectly connected areas
Assume:
HSG
Impervious
Open
Wooded
A
98
39
30
B
98
61
55
C
98
74
70
D
98
80
77
HSG'A'= 38.6%
HSG'B'= 0.0%
HSG'C'= 28.6%
32.8%
Cover Condition I SCS CN
Open 62
Wooded 57
II. PRE -DEVELOPMENT -
A. Onsite Impervious Breakdown
Comments
Assume good condition
Assume Rood condition
Contributing Area
Area [sfJ
Area ac
Roadwa Area
0
0.00
Driveway/ Parking Lot
0
0.00
Roof
0
0.00
Sidewalk / Patio
0
0.00
Other
0
0.00
Totals
0
0.00
B. Watershed Land Use Breakdown
Contributing Area
SCS CN
Area [sfl
Area acres
Comments
Onsite impervious
98
8,739
0.20
Onsite open
62
425,652
9.77
Assume good condition
Onsite wooded
57
554,597
12.73
Assume good condition
Onsite pond
100
0
0.00
Offsite impervious
98
0
0.00
Offsite open
62
0
0.00
Assume good condition
Offsite wooded
57
0
0.00
Assume good condition
Offsite pond
100
0
0.00
TotaIIC area = 22.70 acres
988,988 sf
Composite SCS CN = 60
% Impervious = 0.9%

Holding Village- North Lake PRE -DEVELOPMENT HYDROLOGY Maria Torres, E.I.
RAP-19000 Sub5 Daniel Gunter
12.16.2019
III. TIME OF CONCENTRATION INFORMATION
Time of concentration is calculated using the SCS Segmental Approach (TR-55).
Segment 1: Overland Flow
Length =
100
ft
Top Elev =
345.00
ft
BotElev =
343.00
ft
Height =
2
ft
Slope =
0.0200
ft/ft
Manning's n =
0.24
dense grasses
P (2-year/24-hour) =
3.45
inches (Wake Forest, NC)
Segment Time =
13.73
minutes
Segment 3: Channel Flow
Length =
588
ft
Top Elev =
254.00
BotElev =
245.00
Height =
9
ft
Slope =
0.0153
ft/ft
Manning's n =
0.045
natural channel
Flow Area =
8.00
sf (assume 4'w x 2'h channel)
Wetted Perimeter =
8.00
If (assume 4' x 2' channel)
Channel Velocity =
4.10
ft/sec
Segment Time =
2.39
minutes
Segment 2: Concentrated Flow
Length =
1177
ft
Top Elev =
343.00
ft
BotElev =
254.00
ft
Height =
89
ft
Slope =
0.0756
ft/ft
Paved ? =
No
Velocity=
4.44
ft/sec
Segment Time =
4.42
minutes
Time of Concentration = 20.54 minutes
SCS Lag Time = 12.32 minutes (SCS Lag = 0.6* Tc)
Time Increment = 3.57 minutes (= 0.29*SCS Lag)

Holding Village- North Lake PRE -DEVELOPMENT HYDROLOGY Maria Torres, E.I.
RAP-19000 SubG Daniel Gunter
12.16.2019
Soils from WebSoilSurvey are only inclusive of indirectly connected areas
Assume:
HSG
Impervious
Open
Wooded
A
98
39
30
B
98
61
55
C
98
74
70
D
98
80
77
HSG'A'= 38.6%
HSG'B'= 0.0%
HSG'C'= 28.6%
32.8%
98
62
57
II. PRE -DEVELOPMENT'
A. Onsite Impervious Breakdown
Assume good condition
Assume good condition
Contributing Area
Area [sfJ
Area ac
Roadwa Area
0
0.00
Driveway/ Parking Lot
0
0.00
Roof
0
0.00
Sidewalk / Patio
0
0.00
Other
0
0.00
Totals
0
0.00
B. Watershed Land Use Breakdown
Contributing Area
SCS CN
Area [sfl
Area acres
Comments
Onsite impervious
98
0
0.00
Onsite open
62
0
0.00
Assume good condition
Onsite wooded
57
123,889
2.84
Assume good condition
Onsite pond
100
0
0.00
Offsite impervious
98
0
0.00
Offsite open
62
0
0.00
Assume good condition
Offsite wooded
57
0
0.00
Assume good condition
Offsite pond
100
0
0.00
TotaIIC area = 2.84 acres
123,889 sf
Composite SCS CN = 57
% Impervious = 0.0%

Holding Village- North Lake PRE -DEVELOPMENT HYDROLOGY Maria Torres, E.I.
RAP-19000 SubG Daniel Gunter
12.16.2019
III. TIME OF CONCENTRATION INFORMATI
Time of concentration is calculated using the SCS Segmental Approach (TR-55).
Segment 1: Overland Flow
Length =
100
ft
Top Elev =
331.00
ft
BotElev =
323.00
ft
Height =
8
ft
Slope =
0.0800
ft/ft
Manning's n =
0.40
wooded
P (2-year/24-hour) =
3.45
inches (Wake Forest, NC)
Segment Time =
11.88
minutes
Segmenta3: Channel Flow
Length =
952
ft
Top Elev =
298.00
BotElev=
266.00
Height =
32
ft
Slope =
0.0336
ft/ft
Manning's n =
0.045
natural channel
Flow Area =
6.00
sf (assume 3'w x 2'h channel)
Wetted Perimeter =
7.00
If (assume Tx 2' channel)
Channel Velocity =
5.48
ft/sec
Segment Time =
2.90
minutes
.Segment 2: Concentrated Flow
Length =
180
ft
Top Elev =
323.00
ft
BotElev =
298.00
ft
Height =
25
ft
Slope =
0.1389
ft/ft
Paved ? =
No
Velocity=
6.01
ft/sec
Segment Time =
0.50
minutes
Time of Concentration = 15.27 minutes
SCS Lag Time = 9.16 minutes (SCS Lag = 0.6* Tc)
Time Increment = 2.66 minutes (= 0.29*SCS Lag)

Holding Village - North Lake PRE -DEVELOPMENT HYDROLOGY
RAP-19000 Sub?
Soils from WebSoilSurvey are only inclusive of indirectly connected areas
Assume:
HSG
Impervious
Open
Wooded
A
98
39
30
B
98
61
55
C
98
74
70
D
98
80
77
s
HSG'A'= 38.6%
HSG'B'= 0.0%
HSG'C'= 28.6%
32.8%
II. PRE -DEVELOPMENT'
A. Onsite Impervious Breakdown
98
62
57
Assume good condition
Assume good condition
Contributing Area
Area [sfJ
Area ac
Roadwa Area
0
0.00
Driveway/ Parking Lot
0
0.00
Roof
0
0.00
Sidewalk / Patio
0
0.00
Other
0
0.00
Totals
0
0.00
B. Watershed Land Use Breakdown
Maria Torres, E.I.
Daniel Gunter
12.16.2019
Contributing Area
SCS CN
Area [sfl
Area acres
Comments
Onsite impervious
98
0
0.00
Onsite open
62
88,949
2.04
Assume good condition
Onsite wooded
57
276,184
6.34
Assume good condition
Onsite pond
100
38,035
0.87
Offsite impervious
98
0
0.00
Offsite open
62
0
0.00
Assume good condition
Offsite wooded
57
0
0.00
Assume good condition
Offsite pond
100
0
0.00
TotaIIC area = 9.26 acres
403,168 sf
Composite SCS CN = 62
% Impervious = 0.0%

Holding Village- North Lake PRE -DEVELOPMENT HYDROLOGY Maria Torres, E.I.
RAP-19000 Sub? Daniel Gunter
12.16.2019
III. TIME OF CONCENTRATION INFORMATI
Time of concentration is calculated using the SCS Segmental Approach (TR-55).
Segment 1: Overland Flow
Length =
100
ft
Top Elev =
358.00
ft
BotElev =
352.00
ft
Height =
6
ft
Slope =
0.0600
ft/ft
Manning's n =
0.40
wooded
P (2-year/24-hour) =
3.45
inches (Wake Forest, NC)
Segment Time =
13.33
minutes
Segment 3: Channel Flow
Length =
831
ft
Top Elev =
312.00
BotElev=
297.00
Height =
15
ft
Slope =
0.0181
ft/ft
Manning's n =
0.045
natural channel
Flow Area =
6.00
sf (assume 3'w x 2'h channel)
Wetted Perimeter =
7.00
If (assume Tx 2' channel)
Channel Velocity =
4.01
ft/sec
Segment Time =
3.45
minutes
.Segment 2: Concentrated Flow
Length =
568
ft
Top Elev =
352.00
ft
BotElev =
312.00
ft
Height =
40
ft
Slope =
0.0704
ft/ft
Paved ? =
No
Velocity=
4.28
ft/sec
Segment Time =
2.21
minutes
Time of Concentration = 18.99 minutes
SCS Lag Time = 11.39 minutes (SCS Lag = 0.6* Tc)
Time Increment = 3.30 minutes (= 0.29*SCS Lag)

Holding Village - North Lake PRE -DEVELOPMENT HYDROLOGY Maria Torres, E.I.
RAP-19000 Reach Daniel Gunter
12.16.2019
Reach 1: Channel Flow
Length =
Top Elev =
Bot Elev =
Height =
Slope =
Manning's n =
Flow Area =
Wetted Perimeter =
Channel Velocity =
Segment Time =
Reach 2: Channel Flow
Length =
Top Elev =
Bot Elev =
Height =
Slope =
Manning's n =
Flow Area =
Wetted Perimeter =
Channel Velocity =
Segment Time =
Reach 3: Channel Flow
Length =
Top Elev =
Bot Elev =
Height =
Slope =
Manning's n =
Flow Area =
Wetted Perimeter =
Channel Velocity =
Segment Time =
587
ft
245.00
241.00
4
ft
0.0068
ft/ft
0.045
natural channel
12.00
sf (assume 4'w x Th channel)
12.00
If (assume 4' x T channel)
2.73
ft/sec
3.58
minutes
1002
ft
266.00
245.00
21
ft
0.0210
ft/ft
0.045
natural channel
8.00
sf (assume 4'w x Th channel)
8.00
If (assume 4' x T channel)
4.79
ft/sec
3.48
minutes
985
ft
297.00
266.00
31
ft
0.0315
ft/ft
0.045
natural channel
6.00
sf (assume Tw x Th channel)
7.00
If (assume Tx T channel)
5.30
ft/sec
3.10
minutes