SW6230801_Design Calculations_20230810

STORMWATER CALCULATIONS FOR
GRETCHEN PINES PHASE 5
MOORE COUNTY
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PREPARED BY:
Ken Bright Associates, PLLC
P.O. Box 553
Sanford, NC 27331
[phone]
[e-mail]
AUGUST 1, 2023

SWALES

SWALE DESIGN
PROJ: GRETCHEN PINES PHASE 5
DATE: 07/15/23
FILE: SWALE-1-GP5.xlsx
INPUT: SWALE# 1 RD 2 STA 6+15 TO CUL DE SAC NORTH SIDE
C Area(Ac; C X A Area= 1.3 Ac PRECIPITATION
Asphalt 0.95 0.13 0.12 C= 0.23 Weighted C from above 25-Yr
Commercial 0.7 0 0.00 Tc= 5 minutes; 5-min: 8.75
Bare 0.3 0.00 125 8.75 IN/HR FROM NOOA 10-min: 6.97
Bldg 0.95 0 0.00 type channel: TRI 15-min: 5.89
Lawn 0.15 1.17 0.18 Bottom width = 0 if triangular must be zero 30-min: 4.36
Gravel 0.4 0 0.00 Channel slope= 2.1 % 60-min: 2.9
Total 1.3 0.30 Side slope= 4 ft per ft
Weighted C= 0.23
Impervious Ac= 0.13 Q25= 2.62 cfs
Pervious Ac= 1.17
if velocity greater than 2 fps on bare earth then use temporary liner
condition 'depth ft. Q25 cfs In (comments velocity area hydraulic Wetted Top width
2.62 ft/sec SF radius Perimete ft.
bare earth 03 1.08 0.020'check 2.99 0.36 0.15 2.47 2.4
1NA Green S75 0.5; 2.62 0.032 okay 2.62 1.00 0.24 4.12_ 4
Shear stress= 0.66 lb per sq.ft.,formula T=yds, page 8.05.12
comments: Use NA Green S75
LINING T(Ib/sf) NA Green' T(Ib/sf)
Excelsior Mat 1.55 NA Green S75= 1.55
Straw with net 1.45 NA Green S150= 1.75
Class B Rip-Rap 3 NA Green SC150= 2.1
Class 1 Riprap 5 NA Green C125 T= 2.25
Class 2 Riprap 7.5 NA Green C125 BN= 2.54
NA Green P300= 8
Grass checl PERMANENT use figure 8.05c Mannings'n'for grass-make sure HR times velocity yields same n
grass type: use fescue which has a velocity capacity of 4.5 fps for velocity 4.5 fps
VR-
hydraulice
radius
grass Bottom width depth ft. Q25 cfs n from tab n from times comments velocity area of R-hydraulic Wetted Top width
condition 2.62 curve Vel calculate _ fps channel radius Perimeter ft.
_ computed sq.ft. ft.
0.00 0.9 2.68 0.150 0.36 HR okay Depth OK 0.83 3.24 0.44 7.42 7.2
L.
0.00 0.73 1 2.88 0.080 0.48 HR okay Depth OK 1.35 2.13 0.35 6.02 5.84
use depth= ft.
7/17/2023, 3:31 PM

SWALE DESIGN
PROJ: GRETCHEN PINES PHASE 5
DATE: 07/15/23
FILE: SWALE-2-GP5.xlsx
INPUT: SWALE# 2 RD 2 STA 6+15 TO CUL DE SAC WEST SIDE
C 'Area(Ac; C X A Area= 0.32 Ac PRECIPITATION
Asphalt 0.95 0.18 0.17 C= 0.60 Weighted C from above 25-Yr
Commercial 0.7 0 0.00 Tc= 5 minutes; 5-min: 8.75
Bare 0.3 0.00 125 8.75 IN/HR FROM NOOA 10-min: 6.97
Bldg 0.95 0 0.00 type channel: TRI 15-min: 5.89
Lawn 0.15 0.14 0.02 Bottom width = 0 if triangular must be zero 30-min: 4.36
Gravel 0.4 0 0.00 Channel slope= 2.1 % 60-min: 2.9
Total 0.32 0.19 Side slope= 4 ft per ft
Weighted C= 0.60
Impervious Ac= 0.18 ( Q25= t._ cfs
Pervious Ac= 0.14
if velocity greaterthan 2 fps on bare earth then use temporary liner
condition 'depth ft. Q25 cfs (n 'comments velocity area hydraulic Wetted Top width
1.68 I ft/sec SF radius Perimete ft.
bare earth 03 1.08 0.020 check 2.99 0.36 0.15 2.47 2.4
NA Green S75 0.45 1.98 0.032 okay 2.45 0.81 0.22 3.71 3.6 ,
Shear stress= 0.59 lb per sq.ft.,formula T=yds, page 8.05.12
comments: Use NA Green S75
LINING T(Ib/sf) NA Green T(lb/sf)
Excelsior Mat 1.55 NA Green S75= 1.55
Straw with net 1.45 NA Green S150= 1.75
Class B Rip-Rap 3 NA Green SC150= 2.1
Class 1 Riprap 5 NA Green C125 T= 2.25
Class 2 Riprap 7.5 NA Green C125 BN= 2.54
NA Green P300= 8
Grass checl PERMANENT use figure 8.05c Mannings'n'for grass-make sure HR times velocity yields same n
grass type: use fescue which has a velocity capacity of 4.5 fps for velocity 4.5 fps
VR-
hydraulice
radius
grass Bottom width depth ft. Q25 cfs n from tab n from times comments velocity area of R-hydraulic Wetted Top width
condition 1.68 curve Vel calculate fps channel radius Perimeter ft.
computed sq.ft. ft.
E
0.00 0.9 2.01 0.200 0.27 HR okay Depth OK 0.62 3.24 0.44 7.42 7.2
0.00 0.65 1.82 0.093 0.34 HR okay Depth OK 1.08 1.69 0.32 5.36 5.2
use depth = ft.
7/17/2023, 3:30 PM

SWALE DESIGN
PROJ: GRETCHEN PINES PHASE 5
DATE: 07/15/23
FILE: SWALE-3-GP5.xlsx
INPUT: SWALE# 3 PEWTER TO 0+00 PIPE
C Area(Ac; C X A Area= 8.28 Ac PRECIPITATION
Asphalt 0.95 0.43 0.41 C = 023 Weighted C from above 25-Yr
Commercial 0.7 0 0.00 Tc= 5 minutes; 5-min: 8.75
Bare 0.3 0.00 125 8.75 IN/HR FROM NOOA 10-min: 6.97
Bldg 0.95 0.38 0.36 type channel: TRAP 15-min: 5.89
Lawn 0.15 7.47 1.12 Bottom width = 2 if triangular must be zero 30-min: 4.36
Gravel 0.4 0 0.00 Channel slope= 8 % 60-min: 2.9
Total 8.28 1.89 Side slope= 4 ft per ft
Weighted C= 0.23
Impervious Ac= 0.81 Q25= 16.54 cfs
Pervious Ac= 7.47
if velocity greater than 2 fps on bare earth then use temporary liner
condition 'depth ft. Q25 cfs In 'comments velocity area hydraulic Wetted Top width
16.54 ft/sec SF radius Perimete ft.
bare earth 0.3 7.25 0.020 check 7.55 0.96 0.21 4.47 4.4
NA Green C125 BN 0.48 14.71 - 0.025 check 7.82 1.88 0.32 5.96 5.84
Shear stress= 2.40 lb per sq.ft.,formula T=yds, page 8.05.12
comments: Use NA Green C125 BN
LINING T(Ib/sf) NA Green T(Ib/sf)
Excelsior Mat 1.55 NA Green S75= 1.55
Straw with net 1.45 NA Green S150= 1.75
Class B Rip-Rap 3 NA Green SC150= 2.1
Class 1 Riprap 5 NA Green C125 T= 2.25
Class 2 Riprap 7.5 NA Green C125 BN= 2.54
NA Green C350= 3.2
Grass checi PERMANENT use figure 8.05c Mannings'n'for grass-make sure HR times velocity yields same n
grass type: use bermuda which has a velocity capacity of 5 fps fo velocity 4.5 fps
VR-
hydraulice
radius
grass Bottom width depth ft. Q25 cfs n from tab n from times comments velocity area of R-hydraulic Wetted Top width
condition 16.54 curve Vel calculate fps channel radius Perimeter ft.
computed sq.ft. ft.
2.00 0.86 16.88 0.075 1.86 HR okay Depth OK 3.61 4.68 0.51 9.09 8.88
L.
2.00 0.71 16.69 0.050 2.13 HR okay Depth OK 4.86 3.44 0.44 7.85 7.68
use depth= ft.
7/26/2023, 5:33 PM

SWALE DESIGN
PROJ: GRETCHEN PINES PHASE 5
DATE: 07/15f23
FILE: SWALE-4.xlsx
INPUT: SWALE# 4 Road 2 sta 2+00 to St 6+15 west
C 'Area(Ac; C X A Area= 0.29 Ac PRECIPITATION
Asphalt 0.95 0.07 0.07 C= 0 34 Weighted C from above 25-Yr
Commercial 0.7 0 0.00 Tc= 5 minutes; 5-min: 8.75
Bare 0.3 0.00 - 125 8.75 IN/HR FROM NOOA 10-min: 6.97
Bldg 0.95 0.00 type channel: TRI 15-min: 5.89
Lawn 0.15 0.22 0.03 Bottom width = 0 if triangular must be zero 30-min: 4.36
Gravel 0.4 0 0.00 Channel slope= 7 % 60-min: 2.9
Total 0.29 0.10 Side slope= 4 ft per ft
Weighted C= 0.34
Impervious Ac= 0.07 ( Q25= 0.87 cfs
Pervious Ac= 0.22
if velocity greater than 2 fps on bare earth then use temporary liner
condition 'depth ft. IQ25 cfs In comments velocity area hydraulic Wetted Top width
0.87 ft/sec SF radius Perimete ft.
bare earth 0.2 0.67 -0.020 check 4.16 0.16 0.10 1.65 1.6
NA Green S75 0.27 0.93 0.032 okay 3.18 0.29 0.13 2.23 2.16
Shear stress= 1.18 lb per sq.ft.,formula T=yds, page 8.05.12
comments: Use NA Green S75
LINING T(Ibis') NA Green' T(Ib/sf)
Excelsior Mat 1.55 NA Green S75= 1.55
Straw with net 1.45 NA Green S150= 1.75
Class B Rip-Rap 3 NA Green SC150= 2.1
Class 1 Riprap 5 NA Green C125 T= 2.25
Class 2 Riprap 7.5 NA Green C125 BN= 2.54
NA Green C350= 3.2
Grass checl PERMANENT use figure 8.05c Mannings'n'for grass-make sure HR times velocity yields same n
grass type: use fescue which has a velocity capacity of 4.5 fps for velocity 4.5 fps
VR-
hydraulice
radius
grass Bottom width depth ft. Q25 cfs n from tab n from times comments velocity area of R-hydraulic Wetted Top width
condition 0.87 curve Vel calculate fps channel radius Perimeter ft.
computed sq.ft. ft.
0.00 0.6 1.13 0.220 0.23 HR okay Depth OK 0.79 1.44 0.29 4.95 4.8
IL 0.00 0.41 0.90 0.100 0.27 HR okay Depth OK 1.34 0.67 0.20 3.38 3.28
use depth= ft.
7/17/2023, 3:43 PM

SWALE DESIGN
PROJ: GRETCHEN PINES PHASE 5
DATE: 07/15123
FILE: SWALE-5A.xlsx
INPUT: SWALE# 5A Pewter Pipe to Sta 7+27
C 'Area(AcJ C X A Area= 1.33 Ac PRECIPITATION
Asphalt 0.95 0.23 0.22 C= 0.35 Weighted C from above 25-Yr
Commercial 0.7 0 0.00 Tc= 5 minutes; 5-min: 8.75
Bare 0.3 0.00 125 8.75 IN/HR FROM NOOA 10-min: 6.97
Bldg 0.95 0.1 0.10 type channel: TRI 15-min: 5.89
Lawn 0.15 1 0.15 Bottom width = 0 if triangular must be zero 30-min: 4.36
Gravel 0.4 0 0.00 Channel slope= 9.5 % 60-min: 2.9
Total 1.33 0.46 Side slope= 4 ft per ft
Weighted C= 0.35
Impervious Ac= 0.33 I Q25= 4.06 cfs
Pervious Ac= 1.00
if velocity greater than 2 fps on bare earth then use temporary liner
condition !depth ft. IQ25 cfs In (comments velocity area hydraulic Wetted 'Top width
4.06 ft/sec SF radius Perimete ft.
bare earth 0.2 0.78 0.020 check 4.85 0.16 0.10 1.65 1.6
NA Green C125BN 0.44 4.10 0.031 okay 5.29 0.77 0.21 3.63 3.52
Shear stress= 2.61 lb per sq.ft.,formula T=yds, page 8.05.12
comments: Use NA Green C125BN
LINING T(Ib/sf) NA Green T(Ib/sf)
Excelsior Mat 1.55 NA Green S75= 1.55
Straw with net 1.45 NA Green S150= 1.75
Class B Rip-Rap 3 NA Green SC150= 2.1
Class 1 Riprap 5 NA Green C125 T= 2.25
Class 2 Riprap 7.5 NA Green C125 BN= 2.8
NA Green C350= 3.2
Grass checi PERMANENT use figure 8.05c Mannings'n'for grass-make sure HR times velocity yields same n
grass type: use fescue which has a velocity capacity of 4.5 fps for velocity 4.5 fps
VR-
hydraulice
radius
grass Bottom width depth ft. Q25 cfs n from tab n from times comments velocity area of R-hydraulic Wetted Top width
condition 4.06 curve Vel calculate fps channel radius Perimeter ft.
computed ,sq.ft. ft.
0.00 0.76 4.20 0.130 0.67 HR okay Depth OK 1.82 2.31 0.37 6.27 6.08
IL
0.00 0.57 4.22 0.060 0.90 HR okay Depth OK 3.25 1.30 0.28 4.70 4.56
use depth= ft.
7/20/2023, 10:14 AM

SWALE DESIGN
PROJ: GRETCHEN PINES PHASE 5
DATE: 07/15123
FILE: SWALE-6a.xlsx
INPUT: SWALE# 6a Pewter Sta 5+00 to Sta 7+20
C Area(Ac; C X A Area= 3.06 Ac PRECIPITATION
Asphalt 0.95 0.27 0.26 C= 0.30 Weighted C from above 25-Yr
Commercial 0.7 0 0.00 Tc= 5 minutes; 5-min: 8.75
Bare 0.3 0.00 125 8.75 IN/HR FROM NOOA 10-min: 6.97
Bldg 0.95 0.32 0.30 type channel: TRI 15-min: 5.89
Lawn 0.15 2.47 0.37 Bottom width = 2 if triangular must be zero 30-min: 4.36
Gravel 0.4 0 0.00 Channel slope= 9.5 % 60-min: 2.9
Total 3.06 0.93 Side slope= 4 ft per ft
Weighted C= 0.30
Impervious Ac= 0.59 ( Q25= 8.15 cfs
Pervious Ac= 2.47
if velocity greater than 2 fps on bare earth then use temporary liner
condition 'depth ft. Q25 cfs In
comments velocity area hydraulic Wetted Top width
8.15 ft/sec SF radius Perimete ft.
bare earth 0.2 3.69 0.020 check 6.58 0.56 0.15 3.65 3.6
NA Green C125BN 0.35 8.20 0.026 okay 6.89 1.19 0.24 4.89 4.8
Shear stress= 2.07 lb per sq.ft.,formula T=yds, page 8.05.12
'comments: Use NA Green C125BN
LINING T(Ib/sf) NA Green T(Ib/sf)
Excelsior Mat 1.55 NA Green S75= 1.55
Straw with net 1.45 NA Green S150= 1.75
Class B Rip-Rap 3 NA Green SC150= 2.1
Class 1 Riprap 5 NA Green C125 T= 2.25
Class 2 Riprap 7.5 NA Green C125 BN= 2.8
NA Green C350= 3.2
Grass checl PERMANENT use figure 8.05c Mannings'n'for grass-make sure HR times velocity yields same n
grass type: use fescue which has a velocity capacity of 4.5 fps for velocity 4.5 fps
VR-
hydraulice
radius
grass Bottom width depth ft. Q25 cfs n from tab n from times comments velocity area of R-hydraulic Wetted Top width
condition 8.15 curve Vel calculate fps channel radius Perimeter ft.
computed sq.ft. ft.
C 2.00 0.7 6.79 0.130 0.87 HR okay Check Dept 2.02 3.36 0.43 7.77 7.6
D 2.00 0.55 8.42 0.063 1.29 HR okay Depth OK 3.64 2.31 0.35 6.54 6.4
use depth = ft.
7/20/2023, 9:40 AM

SWALE DESIGN
PROJ: GRETCHEN PINES PHASE 5
DATE: 07/15/23
FILE: SWALE-6b.xlsx
INPUT: SWALE# 6b Pewter Sta 7+20 to Cul De Sac
C WArea(Acr; C X A Area= 2.82 Ac PRECIPITATION
Asphalt 0.95 0.2 0.19 C = -" Weighted C from above 25-Yr
Commercial 0.7 0 0.00 Tc= 5 minutes; 5-min: 8.75
Bare 0.3 0.00 125 8.75 IN/HR FROM NOOA 10-min: 6.97
Bldg 0.95 0.32 0.30 type channel: TRI 15-min: 5.89
Lawn 0.15 2.3 0.35 Bottom width = 2 if triangular must be zero 30-min: 4.36
Gravel 0.4 0 0.00 Channel slope= 4 % 60-min: 2.9
Total 2.82 0.84 Side slope= 4 ft per ft
Weighted C= 0.30
Impervious Ac= 0.52 ( Q25= cfs I
Pervious Ac= 2.30
if velocity greater than 2 fps on bare earth then use temporary liner
condition !depth ft. IQ25 cfs In 'comments velocity area hydraulic Wetted Top width
7.34 ft/sec SF radius Perimete ft.
bare earth 0.2 2.39 0.020 4.27 0.56 0.15 3.65 3.6
NA Green S75 0.45 7.36 0.031 4.30 1.71 0.30 5.71 5.6
Shear stress= 1.12 lb per sq.ft.,formula T=yds, page 8.05.12
comments: NA Green S75
LINING T(Ib/sf) NA Green T(Ib/sf)
Excelsior Mat 1.55 NA Green S75= 1.55
Straw with net 1.45 NA Green S150= 1.75
Class B Rip-Rap 3 NA Green SC150= 2.1
Class 1 Riprap 5 NA Green C125 T= 2.25
Class 2 Riprap 7.5 NA Green C125 BN= 2.8
NA Green C350= 3.2
Grass checl PERMANENT use figure 8.05c Mannings'n'for grass-make sure HR times velocity yields same n
grass type: use fescue which has a velocity capacity of 4.5 fps for velocity 4.5 fps
VR-
hydraulice
radius
grass Bottom width depth ft. Q25 cfs n from tab n from times comments velocity area of R-hydraulic Wetted Top width
condition 7.34 curve Vel calculate fps channel radius Perimeter ft.
���--- computed sq.ft. ft.
2.00 0.75 7.38 0.090 0.90 HR okay Depth OK 1.97 3.75 0.46 8.18 8
D 2.00 0.65 1 8.15 0.060 1.11 HR okay Depth OK 2.72 2.99 0.41 7.36 7.2
use depth= ft.
7/26/2023, 4:25 PM

SWALE DESIGN
PROJ: GRETCHEN PINES PHASE 5
DATE: 07/15/23
FILE: SWALE-7.xlsx
INPUT: SWALE# 7 Pewter INTERSECTION TO PIPE
C 'Area(Ac; C X A Area= 1.39 Ac PRECIPITATION
Asphalt 0.95 0.27 0.26 C= 0.37 Weighted C from above 25-Yr
Commercial 0.7 0 0.00 Tc= 5 minutes; 5-min: 8.75
Bare 0.3 0.00 125 8.75 IN/HR FROM NOOA 10-min: 6.97
Bldg 0.95 0.12 0.11 type channel: TRI 15-min: 5.89
Lawn 0.15 1 0.15 Bottom width= 2 if triangular must be zero 30-min: 4.36
Gravel 0.4 0 0.00 Channel slope= 8 % 60-min: 2.9
Total 1.39 0.52 Side slope= 4 ft per ft
Weighted C= 0.37
Impervious Ac= 0.39 I Q25= - cfs I
Pervious Ac= 1 00
if velocity greater than 2 fps on bare earth then use temporary liner
condition 'depth ft. 1Q25 cfs In 'comments velocity area hydraulic Wetted Top width
4.55 _ft/sec SF radius Perimete,ft.
bare earth 0.2 3.38 0.020 check 6.04 0.56 0.15 3.65 3.6
NA Green C125BN 0.3 4.83 0.030 okay 5.03 0.96 0.21 4.47 4.4
Shear stress= 1.50 lb per sq.ft.,formula T=yds, page 8.05.12
comments: Use NA Green C125BN
LINING T(Ib/sf) NA Green T(Ib/sf)
Excelsior Mat 1.55 NA Green S75= 1.55
Straw with net 1.45 NA Green S150= 1.75
Class B Rip-Rap 3 NA Green SC150= 2.1
Class 1 Riprap 5 NA Green C125 T= 2.25
Class 2 Riprap 7.5 NA Green C125 BN= 2.8
NA Green C350= 3.2
Grass checl PERMANENT use figure 8.05c Mannings'n'for grass-make sure HR times velocity yields same n
grass type: use fescue which has a velocity capacity of 4.5 fps for velocity 4.5 fps
VR-
hydraulice
radius
grass Bottom width depth ft. Q25 cfs n from tab n from times comments velocity area of R-hydraulic Wetted Top width
condition 4.55 curve Vel calculates fps channel radius Perimeter ft.
computed sq.ft. ft.
C 2.00 0.55 4.87 0.100 0.74 HR okay Depth OK 2.11 2.31 0.35 6.54 6.4
D 2.00 0.45 5.38 0.060 0.94 HR okay Depth OK 3.14 1.71 0.30 5.71 5.6
use depth= ft.
7/26/2023, 4:27 PM

SWALE DESIGN
PROJ: GRETCHEN PINES PHASE 5
DATE: 07/15/23
FILE: SWALE-8.xlsx
INPUT: SWALE# 8 RD 2 STA 1+50 TO CUL DE SAC SOUTH
C 'Area(Ac, C X A Area= 0.86 Ac PRECIPITATION
Asphalt 0.95 0.2 0.19 C = 0.44 Weighted C from above 25-Yr
Commercial 0.7 0 0.00 Tc= 5 minutes; 5-min: 8.75
Bare 0.3 0.00 125 8.75 IN/HR FROM NOOA 10-min: 6.97
Bldg 0.95 0.11 0.10 type channel: TRI 15-min: 5.89
Lawn 0.15 0.55 0.08 Bottom width= 0 if triangular must be zero 30-min: 4.36
Gravel 0.4 0 0.00 Channel slope= 4.45 %) 60-min: 2.9
Total 0.86 0.38 Side slope= 4 ft per ft
Weighted C = 0.44
Impervious Ac= 0.31 I Q25= cfs l
Pervious Ac= 0 55
if velocity greater than 2 fps on bare earth then use temporary liner
1 condition depth ft. IQ25 cfs In (comments velocity area hydraulic Wetted Top width
3.30 ft/sec SF radius Perimete ft.
bare earth 0.2 0.53 0.020 - 3.32 0.16 0.10 1.65 1.6
NA Green S75 0.47 3.34 0.031 3.78 0.88 0.23 3.88 3.76
Shear stress= 1.31 lb per sq.ft.,formula T=yds, page 8.05.12
comments: NA Green S75
LINING T(Ib/sf) NA Green T(Ib/sf)
Excelsior Mat 1.55 NA Green S75= 1.55
Straw with net 1.45 NA Green S150= 1.75
Class B Rip-Rap 3 NA Green SC150= 2.1
Class 1 Riprap 5 NA Green C125 T= 2.25
Class 2 Riprap 7.5 NA Green C125 BN= 2.8
NA Green C350= 3.2
Grass checl PERMANENT use figure 8.05c Mannings'n'for grass-make sure HR times velocity yields same n
grass type: use fescue which has a velocity capacity of 4.5 fps for velocity 4.5 fps
VR-
hydraulice
radius
grass Bottom width depth ft. Q25 cfs n from tab n from times comments velocity area of R-hydraulic Wetted Top width
condition 3.30 curve Vel calculate fps channel radius Perimeter ft.
_ _computed sq.ft. ft.
C 0.00 0.75 3.60 0.100 0.58 HR okay Depth OK 1.60 2.25 0.36 6.18 6
D 0.00 0.61 1 3.46 0.060 0.69 HR okay Depth OK 2.33 1.49 0.30 5.03 4.88
use depth= ft.
7/20/2023, 11:02 AM

SWALE DESIGN
PROJ: GRETCHEN PINES PHASE 5
DATE: 07/15/23
FILE: SWALE-9.xlsx
INPUT: SWALE# 9 RD 2 STA 1+50 TO CUL DE SAC NORTH
C Area(Ac; C X A Area= 6.23 Ac PRECIPITATION
Asphalt 0.95 0.2 0.19 C = Weighted C from above 25-Yr
Commercial 0.7 0 0.00 Tc= 5 minutes; 5-min: 8.75
Bare 0.3 0.00 125 8.75 IN/HR FROM NOOA 10-min: 6.97
Bldg 0.95 0.73 0.69 type channel: TRI 15-min: 5.89
Lawn 0.15 5.3 0.80 Bottom width= 0 if triangular must be zero 30-min: 4.36
Gravel 0.4 0 0.00 Channel slope= 4.45 % 60-min: 2.9
Total 6.23 1.68 Side slope= 4 ft per ft
Weighted C= 0.27
Impervious Ac= 0.93 I Q25= . cfs I
Pervious Ac= 5.30
if velocity greater than 2 fps on bare earth then use temporary liner
condition (depth ft. Q25 cfs In (comments velocity area hydraulic Wetted 'Top width
14.69 ft/sec SF radius Perimete ft.
bare earth 0.2 0.531 0.020 3.32 0.16 0.10 1.65 1.6
NA Green C125BN 0.82 14.75 I 0.031 5.48 2.69 0.40 6.76 6.56
Shear stress= 2.28 lb per sq.ft.,formula T=yds, page 8.05.12
comments: Use NA Green C125BN
LINING T(Ib/sf) NA Green T(lb/sf)
Excelsior Mat 1.55 NA Green S75= 1.55
Straw with net 1.45 NA Green S150= 1.75
Class B Rip-Rap 3 NA Green SC150= 2.1
Class 1 Riprap 5 NA Green C125 T= 2.25
Class 2 Riprap 7.5 NA Green C125 BN= 2.8
NA Green C350= 3.2
Grass checl PERMANENT use figure 8.05c Mannings'n'for grass-make sure HR times velocity yields same n
grass type: use fescue which has a veloc capacity of 4.5 fps for velocity 4.5 fps
VR-
hydraulice
radius
grass Bottom width depth ft. Q25 cfs n from tab n from times comments velocity area of R-hydraulic Wetted Top width
condition 14.69 curve Vel calculate fps channel radius Perimeter ft.
computed sq.ft. ft.
C 0.00 1.1 ' 14.72 0.068 1.62 HR okay Depth OK 3.04 4.84 0.53 9.07 8.8
D 0.00 1 15.52 0.050 1.88 HR okayDepth OK 3.88 4.00 0.49 8.2 p 5 8
use depth= ft.
7/20/2023, 11:07 AM

SWALE DESIGN
PROJ: GRETCHEN PINES PHASE 5
DATE: 07/15/23
FILE: SWALE-10.xlsx
INPUT: SWALE# 10 RD 2 STA 3+00 TO Sta 6+00
C Area(AcJJ C X A Area= 1.59 Ac PRECIPITATION
Asphalt 0.95 0.11 0.10 C = 0.21 Weighted C from above 25-Yr
Commercial 0.7 0 0.00 Tc= 5 minutes; 5-min: 8.75
Bare 0.3 0.00 125 8.75 IN/HR FROM NOOA 10-min: 6.97
Bldg 0.95 0 0.00 type channel: TRI 15-min: 5.89
Lawn 0.15 1.48 0.22 Bottom width = 0 if triangular must be zero 30-min: 4.36
Gravel 0.4 0 0.00 Channel slope= 7 % 60-min: 2.9
Total 1.59 0.33 Side slope= 4 ft per ft
Weighted C= 0.21
Impervious Ac= 0.11 I Q25= cfs j
Pervious Ac= 1.48
if velocity greater than 2 fps on bare earth then use temporary liner
condition ldepth ft. Q25 cfs In 'comments velocity area hydraulic Wetted Top width
2.86 ft/sec SF radius Perimete ft.
bare earth 0.2 0.67 0.020 4.16 0.16 0.10 1.65 1.6
NA Green SC150 0.435 2.94 0.036 3.88 0.76 0.21 3.59 3.48
Shear stress= 1.90 lb per sq. ft.,formula T=yds, page 8.05.12
comments: NA Green SC150
LINING T(Ib/sf) NA Green( T(lb/sf)
Excelsior Mat 1.55 NA Green S75= 1.55
Straw with net 1.45 NA Green S150= 1.75
Class B Rip-Rap 3 NA Green SC150= 2.1
Class 1 Riprap 5 NA Green C125 T= 2.25
Class 2 Riprap 7.5 NA Green C125 BN= 2.8
NA Green C350= 3.2
Grass checi PERMANENT use figure 8.05c Mannings'n'for grass-make sure HR times velocity yields same n
grass type: use fescue which has a velocity capacity of 4.5 fps for velocity 4.5 fps
VR-
hydraulice
radius
grass Bottom width depth ft. Q25 cfs n from tab n from times comments velocity area of R-hydraulic Wetted Top width
condition 2.86 curve Vel calculates fps channel radius Perimeter ft.
_ computed sq.ft. ft.
C 0.00 0.75 1 3.23 0.140_ 0.52 HR okay Depth OK 1.43 2.25 0.36 6.18 6
D 0.00 0.56 I 2.96 0.070 0.64 HR okay Depth OK 2.36 1.25 0.27 4.62 4.48
use depth= ft.
7/25/2023,6:34 PM

SWALE DESIGN
PROJ: GRETCHEN PINES PHASE 5
DATE: 07/15/23
FILE: SWALE-11.xlsx
INPUT: SWALE# 11 RD 2 STA 0+15-Sta 3+00
C 'Area(Ac; C X A Area= 3.65 Ac PRECIPITATION
Asphalt 0.95 0.11 0.10 C = 0.18 Weighted C from above 25-Yr
Commercial 0.7 0 0.00 Tc= 5 minutes; 5-min: 8.75
Bare 0.3 0.00 125 8.75 IN/HR FROM NOOA 10-min: 6.97
Bldg 0.95 0.03 0.03 type channel: TRI 15-min: 5.89
Lawn 0.15 3.51 0.53 Bottom width= 0 if triangular must be zero 30-min: 4.36
Gravel 0.4 0 0.00 Channel slope= 5 '70 60-min: 2.9
Total 3.65 0.66 Side slope= 4 ft per ft
Weighted C= 0.18
Impervious Ac= 0.14 I Q25= - cfs I
Pervious Ac= 3.51
if velocity greater than 2 fps on bare earth then use temporary liner
condition !depth ft. 1025 cfs In 'comments velocity area hydraulic Wetted Top width
I 5.77 I ft/sec SF radius Perimete ft.
bare earth 0.21 0.56 0.020 check 3.52 0.16 0.10 1.65 1.6
NA Green SC150 0.6 5.85 0.036 okay 4.06 1.44 0.29 4.95 4.8
Shear stress= 1.87 lb per sq.ft.,formula T=yds, page 8.05.12
comments: NA Green SC150
LINING T(Ib/sf) NA Green T(Ib/sf)
Excelsior Mat 1.55 NA Green S75= 1.55
Straw with net 1.45 NA Green S150= 1.75
Class B Rip-Rap 3 NA Green SC150= 2.1
Class 1 Riprap 5 NA Green C125 T= 2.25
Class 2 Riprap 7.5 NA Green C125 BN= 2.8
NA Green C350= 3.2
Grass checi PERMANENT use figure 8.05c Mannings'n'for grass-make sure HR times velocity yields same n
grass type: use fescue which has a veloc capacity of 4.5 fps for velocity 4.5 fps
VR-
hydraulice
radius
grass Bottom width depth ft. Q25 cfs n from tab n from times comments velocity area of R-hydraulic Wetted Top width
condition 5.77 curve Vel calculate fps channel radius Perimeter ft.
_ computed sq.ft. ft.
C 0.00 0.75 2.73 0.140r 0.44 HR okay Check Dept 1.21 2.25 0.36 6.18 6
D 0.00 0.56 I 2.50 0.070 0.54 HR okay Check Dept 2.00 1.25 0.27 4.62 4.48
use depth= ft.
7/25/2023,6:39 PM

SWALE DESIGN
PROJ: GRETCHEN PINES PHASE 5
DATE: 07/15/23
FILE: SWALE-12.xlsx
INPUT: SWALE# 12 RD 2 STA 0+15-Sta 3+00
C !.Area(Ac; C X A Area= 0 46 Ac PRECIPITATION
Asphalt 0.95 0.11 0.10 C = ". Weighted C from above 25-Yr
Commercial 0.7 0 0.00 Tc= 5 minutes; 5-min: 8.75
Bare 0.3 0.00 125 8.75 IN/HR FROM NOOA 10-min: 6.97
Bldg 0.95 0 0.00 type channel: TRI 15-min: 5.89
Lawn 0.15 0.35 0.05 Bottom width = 0 if triangular must be zero 30-min: 4.36
Gravel 0.4 0 0.00 Channel slope= 5 °%0 60-min: 2.9
Total 0.46 0.16 Side slope= 4 ft per ft
Weighted C= 0.34
Impervious Ac= 0.1 1 I Q25= cfs I
Pervious Ac= 0.35
if velocity greater than 2 fps on bare earth then use temporary liner
condition (depth ft. IQ25 cfs In 'comments velocity area hydraulic Wetted Top width
1.37 I ft/sec SF radius Perimete ft.
bare earth 0.2 0.56 0.020 heck 3.52 0.16 0.10 1.65 1.6
NA Green S75 0.35 1.39 0.036 :say 2.84 0.49 0.17 2.89 2.8
Shear stress= 1.09 lb per sq. ft.,formula T=yds, page 8.05.12
comments: NA Green S75
LINING T(Ib/sf) NA Green T(Ib/sf)
Excelsior Mat 1.55 NA Green S75= 1.55
Straw with net 1.45 NA Green S150= 1.75 4
Class B Rip-Rap 3 NA Green SC150= 2.1
Class 1 Riprap 5 NA Green C125 T= 2.25
Class 2 Riprap 7.5 NA Green C125 BN= 2.8
NA Green C350= 3.2
Grass checl PERMANENT use figure 8.05c Mannings'n'for grass-make sure HR times velocity yields same n
grass type: use fescue which has a velocity capacity of 4.5 fps for velocity 4.5 fps
VR-
hydraulice
radius
grass Bottom width depth ft. Q25 cfs n from tab n from times comments velocity area of R-hydraulic Wetted Top width
condition 1.37 curve VeI calculate fps channel radius Perimeter ft.
computed sq.ft. ft.
C 0.00 0.67 1.41 0.200[ 0.26 HR okay Depth OK 0.79 1.80 0.32 5.52 5.36
D 0.00 0.5 1.44 _ 0.090 0.35 HR okay Depth OK 1.44 1.00 0.24 4.12 4
use depth= ft.
8/2/2023, 4:39 PM

PIPES

PIPE DESIGN
PROJECT: GRETCHEN PINES PHA DATE: 05/03/21
Z:1A-PROJECTSIPROJECTS 20231GRETCHEN PHASE 5 2023.021EROSION CONTROLIPIPESI[PIPE WETLANDS GP-
PHASE5.xlsx]Design
FILE:
FROM TO
PIPE# 1 AT STATION 26+00 APPROX TOWARDS WETLANDS
AREA C ` Area x C
Woods 76.00 0.15 11.4
Road 0.70 0.95 0.665
land use: RESIDENTIAL Sidewalk 0.95 0
composite area= 78.40 Lawn-Sandy soil 0.00 0.13 0
C= 0.17449 Bldg 1.70 0.95 1.615
Residential 0.17 0
Additional Flow= 0 cfs Commercial 0.6 0
Enter storm event Total 13.68
Enter Q10 or Q25 Q10 soil type: (Total Area J 78.4 C-aver= 0.17
Tc= 30 minutes;caculate from Fig.8.03a,use 5 minutes minimum
pipe: type pipe: RCP (type RCP or PVC) TIME OF CONCENTRATION-RATIONAL METHOC
pipe n= Table 8.05b or bureau of rds or malcolm C-COEFF 0.18
pipe slope to talc trial size C31 = 2.5 % Length= ft. L= 2581
channel: type channel SLOPE 4.9
width= 0 ft. must be zero for triangular
slope= 4.4 %for receiving ditch tc= 49.7954462 MIN
side slope= 3 ft per ft USE Tc= 30 min
Kb adjust= 1 fmm Fig8.05d(tria use 1)
WEST END
Storm I(in/hr) Q-cfs DIAM-IN Use Diam Area-Full HW-depth-FT HW/D Velocity(ft/sec) PIPE INV
10-yr 3.88 53.1 27.8 36.0 7.07 3.9 1.3 7.5 514 517.9321
25-yr 4.36 59.6 29.0 36.0 7.07 4.6 1.5 8.4 514 518.5711
100--yr 5.02 68.7 30.6 30.0 4.91 9.7 3.9 14.0 514 523.6921
USE PIPE SIZE INCHES 36 RCP 2.5i% Cd= 0.60 (0,6 TYP)
apron: if Q<3 cfs use 2'x3'apror maintain 2.5 fps min
L
PIPE OUTLET STATBIIZATION STRUCTURE
flow conditior free outlet
length apron 20 enter from Fig.8.06a inlet control
width apron downstrear 23
apron width at pipe 9 ft. comments: USE 9'x20'Lx23'apron
flow conditior submerged
length apron ' 20 enter from Fig.8.06b outlet control
width apron downstrear 11.00
apron width at pipe 9.00 ft.or if flared end used same width as outlet 8/2/2023

PIPE DESIGN
PROJECT: GRETCHEN PINES PHA DATE: 05/03/21
Z:1A-PROJECTSIPROJECTS 20231GRETCHEN PHASE 5 2023.021EROSION CONTROUPIPESI[PIPE rd 2-
south.xlsx]Design
FILE:
FROM TO
PIPE# . , intersection of pewter and rod 2 south
AREA C Area x C
Woods 0.15 0
Road 0.26 0.95 0.247
land use: RESIDENTIAL Sidewalk 0.95 0
composite area= 6.32 Lawn-Sandy soil 5.68 0.15 0.852
C= 0.231013 Bldg 0.38 0.95 0.361
Residential 0.17 0
Additional Flow= C cfs Commercial 0.6 0
Enter storm event Total 1.46
Enter Q10 or Q25 Q10 soil type: (Total Area 1 6.3 C-aver= 0.23
Tc= 30 minutes;caculate from Fig. 8.03a,use 5 minutes minimum
pipe: type pipe: RCP (type RCP or PVC) TIME OF CONCENTRATION-RATION/
pipe n= 0 01.33 Table 8.05b or bureau of rds or malcolm C-COEFF 0.18
pipe slope to talc trial size C31 = 4.9 % Length= ft. L= 2581
channel: type channel SLOPE 4.9
width= 0 ft. must be zero for triangular
slope= 4.9 %for receiving ditch tc= 49.7954462 MIN
side slope= 3 ft per ft USE Tc= 30 min
Kb adjust= 1 frm Fig8.05d(tria use 1)
WEST END
Storm I(in/hr) Q-cfs DIAM-IN Use Diam Area-Full HW-depth-FT HW/D Velocity(ft/sec)
10-yr 7.94 11.6 13.9 18.0 1.77 2.6 1.7 6.6
25-yr 8.75 12.8 14.4 18.0 1.77 3.0 2.0 7.2
100--yr 9.79 14.3 15.0 18.0 1.77 3.6 2.4 8.1
USE PIPE SIZE INCHES 18 RCP % Cd= 0.60 (0,6 TYP)
apron. if Q<3 cfs use 2'x3'apror maintain 2.5 fps min
11
PIPE OUTLET STATBIIZATION STRUCTURE
flow conditior free outlet
length apron 10 enter from Fig.8.06a inlet control
width apron downstrear 11.5
apron width at pipe 4.5 ft. comments: USE 4.5'x11'Lx11.5'apron
flow conditior submerged
length apron 20 enter from Fig.8.06b outlet control
width apron downstrear 9.50
apron width at pipe 4.50 ft.or if flared end used same width as outlet 8/2/2023