SW6220505_Design Calculations_20221220 (2)

Project Name Riprap Dissipator #1 Date
Shahbain Reserve - Phase 1 Sep, 2021
DD Project No.
Location Double D Engineering, PLLC DD2018
Hoke County, North Carolina 150 S. Page Street Calculated By
Southern Pines, NC 28387 J LH
[phone] Checked By
JLH
STORM DESIGN: 10 Year
BACKGROUND: Use the E&S Control Planning
REFERENCE: (NCOEHNR, 1993)
Step 1, Minimum Tailwater Condition
Step 2. D-o =
36 in.
D-o =
3.00 ft.
Q-25 =
43.29 cfs
d-50 =
0.7 ft.
L-a =
20 ft.
Step 3. 3`D-o =
9.00 ft.
W =
23.00 ft.
Step 4. d-max 1.05 ft.
d-max 13 in.
Step 5. Thickness = 1.58 ft.
Thickness = 19 in.
DESIGN DIMENSIONS:
Manual, Section 8.06.
Pipe diameter in inches
Pipe diameter in feet
Pipe outlet (from drainage calculations)
from Figure 8.06 a
from Figure 8.06 a
3 times the outlet pipe diameter
Pipe diameter + Apron length
Maximum Stone Diameter (1.5*d-50) in inches
Maximum Stone Diameter (1.5*d-50) in feet
Min. Apron Thickness With Filter Fabric (1.5*d-max) in feet
Min. Apron Thickness With Filter Fabric (1.5*d-max) in inches
Apron Dimensions
Riprap
Class
_Len..c
t Width
3-D-o
Thick
20
23
9
36in.
2
RMINOLOGY: Q10 = I 0-Yei ir Design Storm, Peak Discharge, (cfs)
D-o = Pipe Diameter, (in. & ft.)
d-50 = Mean t Dne Diameter of Rip -Rap, (ft.)
L-a = Lengt Rip -Rap Apron, (ft.)
3*D-o = Width f Rip -Rap Apron @ Pipe Outlet, (ft.)
W = Width f Rip -Rap Apron @ End of Apron, (ft.)
d-max = Maxim jr n Stone Diameter of Rip -Rap, (ft. & in.)
Thickness = Thickn s of Rip -Rap Apron With Filter Fabric, (ft. &in.)

Project Name Riprap Dissipator #2 Date
Shahbain Reserve - Phase 1 Apr, 2022
DD Project No.
Location Double D Engineering, PLLC DD2115
Hoke County, North Carolina 150 S. Page Street Calculated By
Southern Pines, NC 28387 JLH
[phone] Checked By
JL11
STORM DESIGN: 10 Year
BACKGROUND: Use the E&S Control Planning & Design Manual, Section 8.06.
REFERENCE: (NCDEHNR, 1993)
Step 1. Minimum Tailwater Condition
Step 2.
D-o =
30 in.
D-o =
2.50 ft.
Q-25 =
21.17 cfs
d-50 =
0.5 ft.
L-a =
16 ft.
Step 3.
3*D-o =
7.50 ft.
W =
18.50 ft.
Step 4.
d-max
0.75 ft.
d-max
9 in.
Step 5.
Thickness =
1.13 ft.
Thickness =
14 in.
DESIGN DIMENSIONS:
Pipe diameter in inches
Pipe diameter in feet
Pipe outlet (from drainage calculations)
from Figure 8.06 a
from Figure 8.06 a
3 times the outlet pipe diameter
Pipe diameter + Apron length
Maximum Stone Diameter (1.5*d-50) in inches
Maximum Stone Diameter (1.5*d-50) in feet
Min. Apron Thickness With Filter Fabric (1.5*d-max) in feet
Min. Apron Thickness With Filter Fabric (1.5*d-max) in inches
Apron Dimensions
Riprap
Lent
It
Width
3-D-o
Thick I
Class
16
19
8
24in.
1
TERMINOLOGY: Q10 = 10-Ye
r Design Storm, Peak Discharge, (cfs)
D-o = Pipe Ciarneter,
(in. & ft.)
d-50 = Mean
t ne Diameter of Rip -Rap, (ft.)
L-a = Lengt
f Rip -Rap Apron, (ft.)
3*D-o = Width
Rip -Rap Apron @ Pipe Outlet, (ft.)
W = Width
Rip -Rap Apron @ End of Apron, (ft.)
d-max = Maxim
ir ri Stone Diameter of Rip -Rap, (ft. & in.)
Thickness = Thick
s of Rip -Rap Apron With Filter Fabric, (ft. &in.)

Project Name Riprap Dissipator #3 Date
Shahbain Reserve - Phase 1 Apr, 2022
DID Project No.
Location Double D Engineering, PLLC 11D2115
Hoke County, North Carolina 150 S. Page Street Calculated By
Southern Pines, NC 28387 JLH
[phone] Checked By
JLH
STORM DESIGN: 10 Year
BACKGROUND: Use the E&S Control Planning & Design Manual, Section 8.06.
REFERENCE: (NCOEHNR, 1993)
Step 1. Minimum Tailwater Condition
Step 2.
D-o =
30 in.
D-o =
2.50 ft.
Q-10 =
28.17 cfs
d-50 =
0.5 ft.
L-a =
16 ft.
Step 3.
3*D-o =
7.50 ft_
W =
18.50 ft.
Step 4.
d-max
0.75 ft.
d-max
9 in.
Step 5.
Thickness =
1,13 ft_
Thickness =
14 in.
DESIGN DIMENSIONS:
Pipe diameter in inches
Pipe diameter in feet
Pipe outlet (from drainage calculations)
from Figure 8.06 a
from Figure 8.06 a
3 times the outlet pipe diameter
Pipe diameter + Apron length
Maximum Stone Diameter (1.5*d-50) in inches
Maximum Stone Diameter (1.5*d-50) in feet
Min. Apron Thickness With Filter Fabric (1.5'd-max) in feet
Min. Apron Thickness With Filter Fabric (1.5*d-max) in inches
Apron Dimensions
Riprap
Len
t
Width
3-D-o
Thick
Class
1
19
8
24in.
1
TERMINOLOGY: Q10 = 10-Ye ar Design Storm, Peak Discharge, (cfs)
D-o = Pipe I ie meter, (in. & ft.)
d-50 = Mean Slone Diameter of Rip -Rap, (ft.)
L-a = Lengtl i of Rip -Rap Apron, (ft.)
3*D-o = Width 0 Rip -Rap Apron @ Pipe Outlet, (ft.)
W = Width o Rip -Rap Apron @ End of Apron, (ft.)
d-max = Maxirr u Stone Diameter of Rip -Rap, (ft. & in.)
Thickness = Thickre s of Rip -Rap Apron With Filter Fabric, (ft. &in.)

Project Name Riprap Dissipator #4 Date
Shahhain Reserve - Phase 1 Apr, 2022
DD Project No.
Location Double D Engineering, PLLC DD2115
Hoke County, North Carolina 150 S. Page Street Calculated By
Southern Pines, NC 28387 JLH
[phone] Checked By
JLH
DESIGN: 10 Year
tOUND: Use the E&S Control Pla
ERENCE: (NCDEHNR, 1993)
Step 1. Minimum Tailwater Condition
Step 2.
D-o =
24 in.
D-o =
2.00 ft.
Q-10 =
12.73 cis
d-50 =
0.4 ft.
L-a =
13 ft.
Step 3.
3*D-o =
6.00 ft.
W =
15.00 ft.
Step 4.
d-max
0.60 ft.
d-max
7 in.
Step 5. Thickness = 0.90 ft.
Thickness = 1 t in.
DESIGN DIMENSIONS:
Design Manual, Section B.06.
Pipe diameter in inches
Pipe diameter in feet
Pipe outlet (from drainage calculations)
from Figure 8.06 a
from Figure 8.06 a
3 times the outlet pipe diameter
Pipe diameter + Apron length
Maximum Stone Diameter (1.5*d-50) in inches
Maximum Stone Diameter (1.5*d-50) in feet
Min. Apron Thickness With Filter Fabric (1.5*d-max) in feet
Min. Apron Thickness With Filter Fabric (1.5*d-max) in inches
Apron Dimensions
Rlprap
Lent
Width
3-D-o
Thick
Class
1
15
6
24in.
1
INOLOGY: Q10 = 1 0-Ye ar Design Storm, Peak Discharge, (cfs)
D-o = Pipe I liameter, (in. & ft.)
d-50 = Mean Stone Diameter of Rip -Rap, (ft.)
L-a = Lengt1i of Rip -Rap Apron, (ft.)
3*D-o = Width o Rip -Rap Apron @ Pipe Outlet, (ft.)
W = Width o Rip -Rap Apron @ End of Apron, (ft.)
d-max = Maxin un Stone Diameter of Rip -Rap, (ft. & in.)
Thickness = Thickr e s of Rip -Rap Apron With Filter Fabric, (ft. &in.)

Project Name Riprap Dissipator #5 Date
Shahbain Reserve - Phase 1 Apr, 2022
DID Project No.
Location Double D Engineering, PLLC DD211-5
Hoke County, North Carolina 150 S. Page Street Calculated By
Southern Pines, NC 28387 JLH
[phone] Checked By
JLH
STORM DESIGN: 10 Year
BACKGROUND: Use the E&S Control Planning & Design Manual, Section 8.06.
REFERENCE: (NCDEHNR, 1993)
Step 1. Minimum Tailwater Condition
Step 2.
D-o =
24 in.
D-o =
2.00 ft.
0-10 =
38.78 cfs
d-50 =
0.7 ft.
L-a =
22 ft.
Step 3.
3*D-o =
6.0D ft.
W =
24.00 ft.
Step 4.
d-max
1.05 ft.
d-max
13 in.
Step 5.
Thickness =
1.58 ft.
Thickness =
19 in.
DESIGN DIMENSIONS:
Pipe diameter in inches
Pipe diameter in feet
Pipe outlet (from drainage calculations)
from Figure 8.06 a
from Figure 8.06 a
3 times the outlet pipe diameter
Pipe diameter + Apron length
Maximum Stone Diameter (1.5*d-50) in inches
Maximum Stone Diameter (1.5*d-50) in feet
Min. Apron Thickness With Filter Fabric (1.5*d-max) in feet
Min. Apron Thickness With Filter Fabric (1.5*d-max) in inches
Apron Dimensions
Riprap
Len
t
Width
3-D-o
Thick
Class
2
24
6
36in.
2
TERMINOLOGY: Q10 = 10-Ye
ir Design Storm, Peak Discharge, (cfs)
D-o = Pipe I
i meter, (in. & ft.)
d-50 = Mean
3tDne Diameter of Rip -Rap, (ft.)
L-a = LengtIr
of Rip -Rap Apron, (ft.)
3*D-o = Width
Rip -Rap Apron r@ Pipe Outlet, (ft.)
W = Width
3f Rip -Rap Apron @ End of Apron, (ft.)
d-max = Maxim
jin Slone Diameter of Rip -Rap, (ft. & in.)
Thickness = Thickness
of Rip -Rap Apron With Filter Fabric, (ft. &in.)

Project Name Riprap Dissipator # 6 Date
Shahbain Reserve - Phase 1 Apr, 2022
DID Project No.
Location Double D Engineering, PLLC DD2115
Hoke County, North Carolina 150 S. Page Street Calculated By
Southern Pines, NC 28387 JLH
[phone] Checked By
JLH
STORM DESIGN: 10 Year
BACKGROUND: Use the E&S Control Plan
REFERENCE: (NCDEHVR, 1993)
Step 1. Minimum Tallwater Condition
Step 2. D-o = 24 in.
D-o = 2.00 ft.
Q-10 = 27.02 cfs
d-50 = 0.5 ft
L-a = 13 ft.
Step 3. 3*D-o =
6.00 ft.
W =
15.00 ft
Step 4. d-max
0.75 ft.
d-max
9 in.
Step 5. Thickness = 1.13 ft,
Thickness = 14 in.
DESIGN DIMENSIONS:
Design Manual, Section 8.06.
Pipe diameter in inches
Pipe diameter in feet
Pipe outlet (from drainage calculations)
from Figure 8.06 a
from Figure 8.06 a
3 times the outlet pipe diameter
Pipe diameter + Apron length
Maximum Stone Diameter (1.5*d-50) in inches
Maximum Stone Diameter (1.5*d-50) in feet
Min, Apron Thickness With Filter Fabric (1.5*d-max) in feet
Min. Apron Thickness With Filter Fabric (1.5*d-max) in inches
Apron Dimensions
Riprap
Len
itl I
Width
3*D-o Thick
Class
1
15
6 241n,
1
NOLOGY: Q10 = 10-Yew Design Storm, Peak Discharge, (cfs)
❑-o = Pipe i meter, (in. & ft.)
d-50 = Mean S one Diameter of Rip -Rap, (ft.)
L-a = Lengt i of Rip -Flap Apron, (ft.)
3*D-o = Width o Rip -Rap Apron @ Pipe Outlet, (ft.)
W = Width o Rip -Rap Apron @ End of Apron, (ft.)
d-max = Maxi u Stone Diameter of Rip -Rap, (ft. & in.)
Thickness = Thicki e s of Rip -Rap Apron With Filter Fabric, (ft. &in.)

Project Name Riprap Dissipater #7 Date
Shahbain Reserve - Phase 1 Apr, 2022
DD Project No,
Location Double D Engineering, PLLC DD2115
Hoke County, North Carolina 150 S. Page Street Calculated By
Southern Pines, NC 28387 JLH
[phone] Checked By
JLH
RM DESIGN: 10 Year
KGROUND: Use the E&S Control Pla
ERENCE: (NCDEHNR, 1993)
Step 1. Minimum Tailwater Condition
Step 2.
D-o =
24 in.
D-o =
2.00 ft.
Q-10 =
37.00 cfs
d-50 =
0.7 ft.
L-a =
22 ft.
Step 3.
3*D-o =
6.00 ft.
W =
24,00 ft.
Step 4.
d-max
1.05 ft.
d-max
13 in.
Step 5. Thickness = 1.58 ft.
Thickness = 19 in.
DESIGN DIMENSIONS:
Design Manual, Section 8.06.
Pipe diameter in inches
Pipe diameter in feet
Pipe outlet (from drainage calculations)
from Figure 8.06 a
from Figure 8.06 a
3 times the outlet pipe diameter
Pipe diameter + Apron length
Maximum Stone Diameter (1 .5*d-50) in inches
Maximum Stone Diameter (1.5*d-50) in feet
Min. Apron Thickness With Filter Fabric (1.5*d-max) in feet
Min. Apron Thickness With Filter Fabric (1.5*d-max) in inches
Dimensions
Riprap
4Apron
Lan
t
Width
3-D-o
Thick
Class
2
24
6
3Bin.
2
TERMINOLOGY: 010 = 10-Ye3r Design Storm, Peak Discharge, (cfs)
D-o = Pipe I i meter, (in. & ft.)
d-50 = Mean Slone Diameter of Rip -Rap, (ft.)
L-a = Lengtl i of Rip -Rap Apron, (ft.)
3*D-o = Width o Rip -Rap Apron @ Pipe Outlet, (ft.)
W = Width o Rip -Rap Apron @ End of Apron, (ft.)
d-max = Maxi u Stone Diameter of Rip -Rap, (ft. & in.)
Thickness = Thick e ss of Rip -Rap Apron With Filter Fabric, (ft. &in.)