SW6240504_Design Calculations_20240607

Stormwater Narrative & Calculations
For
Tri-County Subdivision
Rufus Johnson Road Gray's Creek, NC
Owner/Developer:
JFJ III Investments, LLC.
Prepared by:
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1110
May 1, 2024
Prepared By:
Kenneth W. Smith Jr., PE PLS
ASmithSite
ACONSULTANTS , PLLC
NC Firm ID # P-2144
121 Bulittle Drive Linden, NC 28356
[e-mail]

Table of Contents
1. Stormwater Narrative
2. Typical Sheet Flow time of Concentration for each drainage area, Calculations of Individual Drainage
Areas, Outlet Swales &Culverts (Rational Method)
3. Outlet Swale& Side Ditch Swale Simulations
4. Culvert Crossing Simulations
5. NOAA Precipitation Information for Tri-County Subdivision Site
6. Rip Rap Apron Outlet Protection Sizing Calculations
7. NCRS Soils Report for site
8. Surface Water Delineation Map by Pilot Environmental

Narrative:
The proposed subdivision development will include 15 single-family,residential lots utilizing a low-density
stormwater design. This subdivision development's total area is 9.60 acres total and is surrounded mostly by
heavily wooded land to the north with Chickenfoot Road to the south&west sides and existing single-family lots
to the south&east which lie along Rufus Johnson Road. Lots will be served by individual, on-site
wastewater/septic systems as well as public water.No grading or excavation will occur outside of the noted limits
of construction, as the developer does not wish to harm the in-situ soils that are suitable for septic systems.
Stormwater for this site will be permitted via NCDEQ's Low Density Stormwater permitting option with a total of
24%impervious area between the streets',lots and miscellaneous areas coverage.Furthermore, each lot will
receive an allotment of 4,506 S.F of impervious,built upon area. Grassed outlet swales with curled wood turf
reinforcement matting and grassed side ditches for the streets' will convey the majority of the runoff from this
proposed development's streets and portion of the lots,while the remainder of the runoff generated shall be
dispersed via sheet flow that is diffused over large grass-vegetated or wooded areas. Individual drainage areas
have been delineated on the plan sheet C-03A labeled"Grading&Drainage Plan with Drainage Areas&
Impervious Information."Here, all individual portions of the site's hydrology are shown in detail and analyzed, in
order to determine the cumulative flow that is tributary to each portion of a side ditch swales along the streets' or
to the outlet swales that will treat&convey the stormwater runoff. All side ditches and outlet swale conveyance
measures have been analyzed for the 10-year storm event while culverts have been analyzed for the l0yr and 25yr
storm events per NCDOT&NCDEQ standards. All rip rap apron outlet protection measures have been size for
the l0yr storm event. A conservative, lower average time of concentration with a short travel length was used for
each swale's drainage area to calculate rational method intensity; however in reality most drainage areas will have
a higher time of concentration due to increased sheet flow runoff travel lengths over sandy, grassed lawns.
Per NCDEQ's guidance on Low Density Stormwater Developments, all side ditch swales and the outlet swales
are vegetated/grassed conveyances that are designed not to erode during 10-year storm events. Velocities have
been verified as well to be acceptable per NCDEQ's Erosion Control Design Manual's table 8.05A—Maximum
Permissible Design Velocities for Vegetated Channels. The vegetated/grassed outlet swales feature 3:1 side slopes
and are at a minimum 100' in length;however almost all of these swales are usually much longer due to the site's
size, layout and the distance to acceptable outlet points and physical topography. The streets' side ditch swales
have 4:1 slopes running from the edge of the road shoulder down to the side ditch's bottom and then with a 3:1
slope that ties back into existing topography. The outlet swale#15 has a 2' wide bottom with 3:1 side slopes as
well as straw wattles to slow down any flow velocity. Again, all proposed side ditch swales &outlet swales are
grassed&turf matted.
Street centerline grades and outlet swale slopes have been analyzed and designed so to minimize discharge
velocities by keeping the grades flatter,which helps to minimize the overall depth of the excavation for these
swales and the disturbance required for the site. Due to the site's extremely flat nature,this is the only option as
well. The intent here is to keep these streets and outlet swales from being unnecessarily deep or wide, so as to not
adversely impact the septic potential of each lot. The erosion control, grading&drainage plans call out for
velocity dissipating devices such as turf reinforcement matting, straw wattle check dams within the outlet swale
and rip rap outlet aprons at the swales' ends as well as the downstream ends of the pipe culverts. Per NCDEQ's
requirements,the site has been evaluated by a wetlands consultant,Pilot Environmental.A small surface water,
and older farm ditch,has been identified by them as a Non-Wetland Water on the portion of the property that is to
remain as undeveloped area within the portion of the parent tract. However,the 30' vegetated buffer is identified
on for that surface water,as reflected on sheets C-01 &C-02, and that feature will not be impacted by this
development as it is several hundred feet to the northeast of this proposed subdivision site and it's swales.

TR55 Tc Worksheet
Hydraflow Express by Intelisolve
Tri-County Subdivision - Typical Shortest Route for Sheet Flow Time of Concentration (Tc) for a
Flatter, Grassed Lawn with sandy soils to a Streets'Side Ditches (worst case scenario)
Description A Sheet flow
Sheet flow is flow over plane surfaces.It usually
Sheet Flow occurs in the headwater of streams.With sheet flow,
Manning's n-value = 0.240 (Dense Grass*) the friction value(Manning's n)is an effective rough-
ness coefficient that includes the effect of raindrop
Flow length (ft) = 75.0 (shortest length noted) impact;drag over the plane surface;obstacles such as
litter,crop ridges,and rocks;and erosion and trans-
Two-year 24-hr precip. ((in)) = 3.69 (per NOAA) portation of sediment.These n values are for very
e (%) = 1.00% (most of the site is flatter) shallow flow depths of about 0.1 foot or so.Table 3-1
Land slope gives Manning's n values for sheet flow for various
surface conditions.
Sheet Flow Tc (min) = 13.93
Table 3-1 Roughness coefficients(Manning's n)for
sheet flow
Surface description n
Smooth surfaces(concrete,asphalt,
gravel,or bare soil) 0.011
Fallow(no residue) 0.05
Cultivated soils:
Residue cover 20% 0.06
Thus, using the value above, the typical swale Residue cover>20% 0.17
Grass:
will likely receive a NOAA derived, Rational Short grass prairie 0.15
Method Intensity (in/hr) following: ss of the Densegraes2/
Bermudagrass 0.41
Range(natural) 0.13
Woods:i'
Light underbrush 0.40
• Intensity for 10 yr storm = 5.6 inches/hour Dense underbrush 0.80
• Intensity for 25 yr storm = 6.3 inches/hour
*Dense grass was chosen to be more
conservative. While Bermudagrass is
typically what grows most prevalently here
in the sandhills area and best for sandier
Furthermore, in reviewing NCDOT's Guidelines for soils like this site, it generally gives an
Drainage Studies & Hydraulic Design as well as unrealistic time of concentration. Thus, this
is why the "Dense Grass" Manning's Value
NCDEQ's Stormwater Design Manual - Sect. B - for sheet flow was used instead.
Stormwater Calculations, the following Rational
Method "C" Runoff Coefficient values were used
for ground coverage types:
• C = 0.9 for impervious surfaces (roads,
concrete, rooftops, etc.)
• C = 0.2 for grassed lawns and flat slopes
(sandy soils - HSG A)

Outlet Drainage Swales - Drainage Areas Summary Table
Cummulative Drainage Areas Built Upon Areas Pervious c c C Runoff
DA# Area Area Street Lots Total Total Area Area Impervious Pervious Composite Q10
(sf) (ac) (sf) (sf) (sf) (ac) (sf) (ac) (cfs)
SWALE 5 5,695 0.13 1,359 1,127 2,486 0.06 3,210 0.07 0.9 0.2 0.51 0.37
SWALE 6 4,217 0.10 1,392 0 1,392 0.03 2,825 0.06 0.9 0.2 0.43 0.23
SWALE 15 233,084 5.35 29,845 32,669 62,514 1.44 170,571 3.92 0.9 0.2 0.39 11.63
Streets'Cuvlerts-Drainage Areas&Runoff Summary Table
Culverts'Cummulative Drainage Areas Runoff
Culvert Size&Location Area(sf) Area(ac) Q10(cfs) Q25i„,,
Single 18"RCP-Future Street Sta 0+22 8,886 0.20 0.61 0.69
Single 18"RCP-Sand Leaf Sta 0+22 76,591 1.76 3.98 4.47
Single 24"RCP-Sand Field Sta 6+67 to 7+32 L 154,973 3.56 7.95 8.95
Dual(2)24"RCP-Sand Field Sta 7+51&7+56 184,995 4.25 9.05 10.18

Cumulative Runoff
Conveyed Through
Individual Drainage Area's Information Built Upon Areas for Individual Drainage Areas Pervious c c c Individual Drainage Area's Runoff the Swale
Individual Drainage Area# Area Area Street Misc. Lots Total Total Area Area Impervious Pervious Composite Intensity Q10 Q10
(sf) (ac) I (sf) (sf) EA (sf) (ac) I (sf) (ac) I in/hr (cfs) (cfs)
Swale 1-SAND FIELD STA.4+45 L 29029 0.67 3558 1 8,064 0.19 20,965 0.48 0.9 0.2 0.39 5.6 1.47 1.47
Swale 2-SAND FIELD STA.3+10 R 6066 0.14 2205 2,205 0.05 3,861 0.09 0.9 0.2 0.45 5.6 0.35 0.35
Swale 3-FUTURE STREET STA.0+22 L 2820 0.06 930 0.25 2,057 0.05 764 0.02 0.9 0.2 0.71 5.6 0.26 0.26
Swale 4-FUTURE STREET STA.0+22 R 3779 0.09 955 955 0.02 2,824 0.06 0.9 0.2 0.38 5.6 0.18 0.18
Swale 5-FUTURE STREET STA.2+24 L 5695 0.13 1359 0.25 2,486 0.06 3,210 0.07 0.9 0.2 0.51 5.6 0.37 0.37
Swale 6-FUTURE STREET STA.2+24 R 4217 0.10 1392 1,392 0.03 2,825 0.06 0.9 0.2 0.43 5.6 0.23 0.23
Swale 7-SAND FIELD STA.4+82 R 13279 0.30 1444 0.5 3,697 0.08 9,582 0.22 0.9 0.2 0.39 5.6 0.67 1.47
Swale 8-SAND LEAF STA.0+22 R 47562 1.09 5219 2 14,231 0.33 33,331 0.77 0.9 0.2 0.41 5.6 2.50 2.50
Swale 9-SAND LEAF STA.0+22 L 15480 0.36 5225 5,225 0.12 10,255 0.24 0.9 0.2 0.44 5.6 0.87 0.87
Swale 10-SAND FIELD STA.6+68L 62902 1.44 1947 3.25 16,592 0.38 46,311 1.06 0.9 0.2 0.38 5.6 3.11 7.95
Swale 11-SAND FIELD STA.7+54 R 11982 0.28 2764 0.25 3,891 0.09 8,092 0.19 0.9 0.2 0.43 5.6 0.66 2.13
Swale 12-SAND FIELD STA.7+54L 20588 0.47 1217 139 1,356 0.03 19,232 0.44 0.9 0.2 0.25 5.6 0.65 8.61
Swale l3-SAND FIELD STA.7+57L 9434 0.22 2190 2,190 0.05 7,244 0.17 0.9 0.2 0.36 5.6 0.44 0.44
Swale l4-SAND FIELD STA.7+57R 5101 0.12 2191 2,191 0.05 2,910 0.07 0.9 0.2 0.50 5.6 0.33 0.33
SWALE 15-OUTLET SWALE 5062 0.12 0 0.00 5,062 0.12 0.9 0.2 0.20 5.6 0.13 11.63

Channel Report
Hydraflow Express Extension for Autodesk®Civil 3D®by Autodesk, Inc. Tuesday,Apr 30 2024
Swale 1 - Sand Field Sta. 4+45L (grassed & turf matted)
Triangular Highlighted
Side Slopes (z:1) = 3.00, 4.00 Depth (ft) = 0.73
Total Depth (ft) = 2.00 Q (cfs) = 1.470
Area (sqft) = 1.87
Invert Elev (ft) = 150.00 Velocity (ft/s) = 0.79
Slope (%) = 0.30 Wetted Perim (ft) = 5.32
N-Value = 0.050 Crit Depth, Yc (ft) = 0.41
Top Width (ft) = 5.11
Calculations EGL (ft) = 0.74
Compute by: Known Q
Known Q (cfs) = 1.47
Elev (ft) Section Depth (ft)
153.00 3.00
152.50 2.50
152.00 - 2.00
151.50 1.50
151.00 1.00
150.50 0.50
150.00 0.00
149.50 -0.50
0 2 4 6 8 10 12 14 16 18
Reach (ft)

Channel Report
Hydraflow Express Extension for Autodesk®Civil 3D®by Autodesk, Inc. Tuesday,Apr 30 2024
Swale 2 - Sand Field Sta. 3+10R (grassed & turf matted)
Triangular Highlighted
Side Slopes (z:1) = 4.00, 3.00 Depth (ft) = 0.43
Total Depth (ft) = 2.00 Q (cfs) = 0.350
Area (sqft) = 0.65
Invert Elev (ft) = 150.00 Velocity (ft/s) = 0.54
Slope (%) = 0.30 Wetted Perim (ft) = 3.13
N-Value = 0.050 Crit Depth, Yc (ft) = 0.23
Top Width (ft) = 3.01
Calculations EGL (ft) = 0.43
Compute by: Known Q
Known Q (cfs) = 0.35
Elev (ft) Section Depth (ft)
153.00 3.00
152.50 2.50
152.00 - 2.00
151.50 1.50
151.00 1.00
150.50 P 0.50
150.00 0.00
149.50 -0.50
0 2 4 6 8 10 12 14 16 18
Reach (ft)

Channel Report
Hydraflow Express Extension for Autodesk®Civil 3D®by Autodesk, Inc. Tuesday,Apr 30 2024
Swale 3 - Future Street Sta. 0+22L (grassed & turf matted)
Triangular Highlighted
Side Slopes (z:1) = 3.00, 4.00 Depth (ft) = 0.38
Total Depth (ft) = 2.00 Q (cfs) = 0.260
Area (sqft) = 0.51
Invert Elev (ft) = 150.00 Velocity (ft/s) = 0.51
Slope (%) = 0.30 Wetted Perim (ft) = 2.77
N-Value = 0.050 Crit Depth, Yc (ft) = 0.21
Top Width (ft) = 2.66
Calculations EGL (ft) = 0.38
Compute by: Known Q
Known Q (cfs) = 0.26
Elev (ft) Section Depth (ft)
153.00 3.00
152.50 2.50
152.00 - 2.00
151.50 1.50
151.00 1.00
150.50 0.50
150.00 0.00
149.50 -0.50
0 2 4 6 8 10 12 14 16 18
Reach (ft)

Channel Report
Hydraflow Express Extension for Autodesk®Civil 3D®by Autodesk, Inc. Tuesday,Apr 30 2024
Swale 4 - Future Street Sta. 0+22R (grassed & turf matted)
Triangular Highlighted
Side Slopes (z:1) = 4.00, 3.00 Depth (ft) = 0.33
Total Depth (ft) = 2.00 Q (cfs) = 0.180
Area (sqft) = 0.38
Invert Elev (ft) = 150.00 Velocity (ft/s) = 0.47
Slope (%) = 0.30 Wetted Perim (ft) = 2.40
N-Value = 0.050 Crit Depth, Yc (ft) = 0.18
Top Width (ft) = 2.31
Calculations EGL (ft) = 0.33
Compute by: Known Q
Known Q (cfs) = 0.18
Elev (ft) Section Depth (ft)
153.00 3.00
152.50 2.50
152.00 - 2.00
151.50 1.50
151.00 1.00
150.50 0.50
150.00 0.00
149.50 -0.50
0 2 4 6 8 10 12 14 16 18
Reach (ft)

Channel Report
Hydraflow Express Extension for Autodesk®Civil 3D®by Autodesk, Inc. Tuesday,Apr 30 2024
Swale 5 - Future Street Sta. 2+24L (grassed & turf matted)
Triangular Highlighted
Side Slopes (z:1) = 3.00, 4.00 Depth (ft) = 0.33
Total Depth (ft) = 2.00 Q (cfs) = 0.370
Area (sqft) = 0.38
Invert Elev (ft) = 150.00 Velocity (ft/s) = 0.97
Slope (%) = 1.25 Wetted Perim (ft) = 2.40
N-Value = 0.050 Crit Depth, Yc (ft) = 0.24
Top Width (ft) = 2.31
Calculations EGL (ft) = 0.34
Compute by: Known Q
Known Q (cfs) = 0.37
Elev (ft) Section Depth (ft)
153.00 3.00
152.50 2.50
152.00 - 2.00
151.50 1.50
151.00 1.00
150.50 0.50
150.00 0.00
149.50 -0.50
0 2 4 6 8 10 12 14 16 18
Reach (ft)

Channel Report
Hydraflow Express Extension for Autodesk®Civil 3D®by Autodesk, Inc. Tuesday,Apr 30 2024
Swale 6 - Future Street Sta. 2+24R (grassed & turf matted)
Triangular Highlighted
Side Slopes (z:1) = 4.00, 3.00 Depth (ft) = 0.28
Total Depth (ft) = 2.00 Q (cfs) = 0.230
Area (sqft) = 0.27
Invert Elev (ft) = 150.00 Velocity (ft/s) = 0.84
Slope (%) = 1.25 Wetted Perim (ft) = 2.04
N-Value = 0.050 Crit Depth, Yc (ft) = 0.20
Top Width (ft) = 1.96
Calculations EGL (ft) = 0.29
Compute by: Known Q
Known Q (cfs) = 0.23
Elev (ft) Section Depth (ft)
153.00 3.00
152.50 2.50
152.00 - 2.00
151.50 1.50
151.00 1.00
150.50 0.50
150.00 0.00
149.50 -0.50
0 2 4 6 8 10 12 14 16 18
Reach (ft)

Channel Report
Hydraflow Express Extension for Autodesk®Civil 3D®by Autodesk, Inc. Tuesday,Apr 30 2024
Swale 7 - Sand Field Sta. 4+82R (grassed & turf matted)
Triangular Highlighted
Side Slopes (z:1) = 4.00, 3.00 Depth (ft) = 0.73
Total Depth (ft) = 2.00 Q (cfs) = 1.470
Area (sqft) = 1.87
Invert Elev (ft) = 150.00 Velocity (ft/s) = 0.79
Slope (%) = 0.30 Wetted Perim (ft) = 5.32
N-Value = 0.050 Crit Depth, Yc (ft) = 0.41
Top Width (ft) = 5.11
Calculations EGL (ft) = 0.74
Compute by: Known Q
Known Q (cfs) = 1.47
Elev (ft) Section Depth (ft)
153.00 3.00
152.50 2.50
152.00 - 2.00
151.50 1.50
151.00 1.00
150.50 0.50
150.00 0.00
149.50 -0.50
0 2 4 6 8 10 12 14 16 18
Reach (ft)

Channel Report
Hydraflow Express Extension for Autodesk®Civil 3D®by Autodesk, Inc. Wednesday, May 1 2024
Swale 8 - Sand Leaf Sta. 0+22 R (grassed & turf matted)
Triangular Highlighted
Side Slopes (z:1) = 4.00, 3.00 Depth (ft) = 0.89
Total Depth (ft) = 2.00 Q (cfs) = 2.500
Area (sqft) = 2.77
Invert Elev (ft) = 150.00 Velocity (ft/s) = 0.90
Slope (%) = 0.30 Wetted Perim (ft) = 6.48
N-Value = 0.050 Crit Depth, Yc (ft) = 0.51
Top Width (ft) = 6.23
Calculations EGL (ft) = 0.90
Compute by: Known Q
Known Q (cfs) = 2.50
Elev (ft) Section Depth (ft)
153.00 3.00
152.50 2.50
152.00 - 2.00
151.50 1.50
151.00 0 1.00
150.50 q,7 0.50
150.00 0.00
149.50 -0.50
0 2 4 6 8 10 12 14 16 18
Reach (ft)

Channel Report
Hydraflow Express Extension for Autodesk®Civil 3D®by Autodesk, Inc. Wednesday, May 1 2024
Swale 9 - Sand Leaf Sta. 0+22 L (grassed & turf matted)
Triangular Highlighted
Side Slopes (z:1) = 3.00, 4.00 Depth (ft) = 0.60
Total Depth (ft) = 2.00 Q (cfs) = 0.870
Area (sqft) = 1.26
Invert Elev (ft) = 150.00 Velocity (ft/s) = 0.69
Slope (%) = 0.30 Wetted Perim (ft) = 4.37
N-Value = 0.050 Crit Depth, Yc (ft) = 0.33
Top Width (ft) = 4.20
Calculations EGL (ft) = 0.61
Compute by: Known Q
Known Q (cfs) = 0.87
Elev (ft) Section Depth (ft)
153.00 3.00
152.50 2.50
152.00 - 2.00
151.50 1.50
151.00 1.00
150.50 - 0.50
150.00 0.00
149.50 -0.50
0 2 4 6 8 10 12 14 16 18
Reach (ft)

Channel Report
Hydraflow Express Extension for Autodesk®Civil 3D®by Autodesk, Inc. Wednesday, May 1 2024
Swale 10 - Sand Field Sta. 6+68 L (grassed & turf matted)
Triangular Highlighted
Side Slopes (z:1) = 3.00, 4.00 Depth (ft) = 1.37
Total Depth (ft) = 2.00 Q (cfs) = 7.950
Area (sqft) = 6.57
Invert Elev (ft) = 150.00 Velocity (ft/s) = 1.21
Slope (%) = 0.30 Wetted Perim (ft) = 9.98
N-Value = 0.050 Crit Depth, Yc (ft) = 0.80
Top Width (ft) = 9.59
Calculations EGL (ft) = 1.39
Compute by: Known Q
Known Q (cfs) = 7.95
Elev (ft) Section Depth (ft)
153.00 3.00
152.50 2.50
152.00 - 2.00
151.50 0 1.50
151.00 1.00
150.50 0.50
150.00 0.00
149.50 -0.50
0 2 4 6 8 10 12 14 16 18
Reach (ft)

Channel Report
Hydraflow Express Extension for Autodesk®Civil 3D®by Autodesk, Inc. Wednesday, May 1 2024
Swale 11 - Sand Field Sta. 7+54 R (grassed & turf matted)
Triangular Highlighted
Side Slopes (z:1) = 4.00, 3.00 Depth (ft) = 0.84
Total Depth (ft) = 2.00 Q (cfs) = 2.130
Area (sqft) = 2.47
Invert Elev (ft) = 150.00 Velocity (ft/s) = 0.86
Slope (%) = 0.30 Wetted Perim (ft) = 6.12
N-Value = 0.050 Crit Depth, Yc (ft) = 0.48
Top Width (ft) = 5.88
Calculations EGL (ft) = 0.85
Compute by: Known Q
Known Q (cfs) = 2.13
Elev (ft) Section Depth (ft)
153.00 3.00
152.50 2.50
152.00 - 2.00
151.50 1.50
151.00 _ 1.00
150.50 0.50
150.00 0.00
149.50 -0.50
0 2 4 6 8 10 12 14 16 18
Reach (ft)

Channel Report
Hydraflow Express Extension for Autodesk®Civil 3D®by Autodesk, Inc. Wednesday, May 1 2024
Swale 12 - Sand Field Sta. 7+54 L (grassed & turf matted)
Triangular Highlighted
Side Slopes (z:1) = 3.00, 4.00 Depth (ft) = 1.41
Total Depth (ft) = 2.00 Q (cfs) = 8.610
Area (sqft) = 6.96
Invert Elev (ft) = 150.00 Velocity (ft/s) = 1.24
Slope (%) = 0.30 Wetted Perim (ft) = 10.27
N-Value = 0.050 Crit Depth, Yc (ft) = 0.83
Top Width (ft) = 9.87
Calculations EGL (ft) = 1.43
Compute by: Known Q
Known Q (cfs) = 8.61
Elev (ft) Section Depth (ft)
153.00 3.00
152.50 2.50
152.00 - 2.00
151.50 1.50
151.00 1.00
150.50 0.50
150.00 0.00
149.50 -0.50
0 2 4 6 8 10 12 14 16 18
Reach (ft)

Channel Report
Hydraflow Express Extension for Autodesk®Civil 3D®by Autodesk, Inc. Wednesday, May 1 2024
Swale 13 - Sand Field Sta. 7+57 L (grassed & turf matted)
Triangular Highlighted
Side Slopes (z:1) = 3.00, 4.00 Depth (ft) = 0.42
Total Depth (ft) = 2.00 Q (cfs) = 0.440
Area (sqft) = 0.62
Invert Elev (ft) = 150.00 Velocity (ft/s) = 0.71
Slope (%) = 0.50 Wetted Perim (ft) = 3.06
N-Value = 0.050 Crit Depth, Yc (ft) = 0.26
Top Width (ft) = 2.94
Calculations EGL (ft) = 0.43
Compute by: Known Q
Known Q (cfs) = 0.44
Elev (ft) Section Depth (ft)
153.00 3.00
152.50 2.50
152.00 - 2.00
151.50 1.50
151.00 1.00
150.50 0 0.50
150.00 0.00
149.50 -0.50
0 2 4 6 8 10 12 14 16 18
Reach (ft)

Channel Report
Hydraflow Express Extension for Autodesk®Civil 3D®by Autodesk, Inc. Wednesday, May 1 2024
Swale 14 - Sand Field Sta. 7+57 R (grassed & turf matted)
Triangular Highlighted
Side Slopes (z:1) = 4.00, 3.00 Depth (ft) = 0.38
Total Depth (ft) = 2.00 Q (cfs) = 0.330
Area (sqft) = 0.51
Invert Elev (ft) = 150.00 Velocity (ft/s) = 0.65
Slope (%) = 0.50 Wetted Perim (ft) = 2.77
N-Value = 0.050 Crit Depth, Yc (ft) = 0.23
Top Width (ft) = 2.66
Calculations EGL (ft) = 0.39
Compute by: Known Q
Known Q (cfs) = 0.33
Elev (ft) Section Depth (ft)
153.00 3.00
152.50 2.50
152.00 - 2.00
151.50 1.50
151.00 1.00
150.50 0.50
150.00 0.00
149.50 -0.50
0 2 4 6 8 10 12 14 16 18
Reach (ft)

Channel Report
Hydraflow Express Extension for Autodesk®Civil 3D®by Autodesk, Inc. Wednesday, May 1 2024
Swale 15 - OUTLET SWALE (grassed & turf matted)
Trapezoidal Highlighted
Bottom Width (ft) = 2.00 Depth (ft) = 1.43
Side Slopes (z:1) = 3.00, 3.00 Q (cfs) = 11.63
Total Depth (ft) = 2.50 Area (sqft) = 8.99
Invert Elev (ft) = 150.00 Velocity (ft/s) = 1.29
Slope (%) = 0.25 Wetted Perim (ft) = 11.04
N-Value = 0.050 Crit Depth, Yc (ft) = 0.72
Top Width (ft) = 10.58
Calculations EGL (ft) = 1.46
Compute by: Known Q
Known Q (cfs) = 11.63
Elev (ft) Section Depth (ft)
153.00 3.00
152.50 2.50
152.00 2.00
151.50 0 1.50
151.00 1.00
150.50 0.50
150.00 0.00
149.50 -0.50
0 2 4 6 8 10 12 14 16 18 20 22
Reach (ft)

Culvert Report
Hydraflow Express Extension for Autodesk®Civil 3D®by Autodesk, Inc. Monday,Apr 29 2024
Single 18inch Culvert Sta 0+22 Future Street (Q10)
Invert Elev Dn (ft) = 153.46 Calculations
Pipe Length (ft) = 64.00 Qmin (cfs) = 0.61
Slope (%) = 0.30 Qmax (cfs) = 0.61
Invert Elev Up (ft) = 153.65 Tailwater Elev (ft) = (dc+D)/2
Rise (in) = 18.0
Shape = Circular Highlighted
Span (in) = 18.0 Qtotal (cfs) = 0.61
No. Barrels = 1 Qpipe (cfs) = 0.61
n-Value = 0.013 Qovertop (cfs) = 0.00
Culvert Type = Circular Concrete Veloc Dn (ft/s) = 0.55
Culvert Entrance = Groove end projecting (C) Veloc Up (ft/s) = 2.55
Coeff. K,M,c,Y,k = 0.0045, 2, 0.0317, 0.69, 0.2 HGL Dn (ft) = 154.35
HGL Up (ft) = 153.94
Embankment Hw Elev (ft) = 154.04
Top Elevation (ft) = 155.24 Hw/D (ft) = 0.26
Top Width (ft) = 56.00 Flow Regime = Inlet Control
Crest Width (ft) = 12.00
Ele',1ft. Single 18inch Culvert Sta 0+22 Future Street(010) Fi,v Depth It
155 235
155.50 - - 1 85
155.00 1.35
154.50 - 0.85
154.00 i,iercD"frpi u.35
153.50 -0.15
153.00 -0.65
152.50 -1.15
0 5 10 15 20 25 30 35 40 45 50 55 60 65 70 80 85
CircularCulvert HGL Embank
Reach(ft)

Culvert Report
Hydraflow Express Extension for Autodesk®Civil 3D®by Autodesk, Inc. Monday,Apr 29 2024
Single 18inch Culvert Sta 0+22 Future Street (Q25)
Invert Elev Dn (ft) = 153.46 Calculations
Pipe Length (ft) = 64.00 Qmin (cfs) = 0.69
Slope (%) = 0.30 Qmax (cfs) = 0.69
Invert Elev Up (ft) = 153.65 Tailwater Elev (ft) = (dc+D)/2
Rise (in) = 18.0
Shape = Circular Highlighted
Span (in) = 18.0 Qtotal (cfs) = 0.69
No. Barrels = 1 Qpipe (cfs) = 0.69
n-Value = 0.013 Qovertop (cfs) = 0.00
Culvert Type = Circular Concrete Veloc Dn (ft/s) = 0.62
Culvert Entrance = Groove end projecting (C) Veloc Up (ft/s) = 2.64
Coeff. K,M,c,Y,k = 0.0045, 2, 0.0317, 0.69, 0.2 HGL Dn (ft) = 154.36
HGL Up (ft) = 153.96
Embankment Hw Elev (ft) = 154.06
Top Elevation (ft) = 155.24 Hw/D (ft) = 0.28
Top Width (ft) = 56.00 Flow Regime = Inlet Control
Crest Width (ft) = 12.00
Elev(ftt Single 18inch Culvert Ste 0.22 Future Street(Q25) H6 Depth,ft:
156.00 2.35
155.50 1.85
155.00 1.35
154.50 - 0.85
.
154.00 ____- -li et contErd 0.35
153.50 - ( - -0.15
153.00 -0.65
152.50 -1.15
0 5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80 85
CircularCulvert HGL Embank Reach(ft)

Culvert Report
Hydraflow Express Extension for Autodesk®Civil 3D®by Autodesk, Inc. Monday,Apr 29 2024
Single 18inch Culvert Sta 0+22 Sand Leaf Dr (Q10)
Invert Elev Dn (ft) = 153.08 Calculations
Pipe Length (ft) = 64.00 Qmin (cfs) = 3.98
Slope (%) = 0.30 Qmax (cfs) = 3.98
Invert Elev Up (ft) = 153.27 Tailwater Elev (ft) = (dc+D)/2
Rise (in) = 18.0
Shape = Circular Highlighted
Span (in) = 18.0 Qtotal (cfs) = 3.98
No. Barrels = 1 Qpipe (cfs) = 3.98
n-Value = 0.013 Qovertop (cfs) = 0.00
Culvert Type = Circular Concrete Veloc Dn (ft/s) = 2.78
Culvert Entrance = Groove end projecting (C) Veloc Up (ft/s) = 4.41
Coeff. K,M,c,Y,k = 0.0045, 2, 0.0317, 0.69, 0.2 HGL Dn (ft) = 154.21
HGL Up (ft) = 154.03
Embankment Hw Elev (ft) = 154.36
Top Elevation (ft) = 154.83 Hw/D (ft) = 0.72
Top Width (ft) = 56.00 Flow Regime = Inlet Control
Crest Width (ft) = 12.00
Elev(ft) Single 18inch Culvert Ste 0+22 Sand Leaf Dr(010) Fi,v Depth It
155.00 1.73
~ r
154.50 1.23
3l filet control
154.00 D 73
153.50 0.23
153.00 -0.27
152.50 -0.77
0 5 10 15 20 25 30 35 40 45 50 55 60 65 70 80 85
CircularCulvert HGL Embank
Reach(ft)

Culvert Report
Hydraflow Express Extension for Autodesk®Civil 3D®by Autodesk, Inc. Monday,Apr 29 2024
Single 18inch Culvert Sta 0+22 Sand Leaf Dr (Q25)
Invert Elev Dn (ft) = 153.08 Calculations
Pipe Length (ft) = 64.00 Qmin (cfs) = 4.47
Slope (%) = 0.30 Qmax (cfs) = 4.47
Invert Elev Up (ft) = 153.27 Tailwater Elev (ft) = (dc+D)/2
Rise (in) = 18.0
Shape = Circular Highlighted
Span (in) = 18.0 Qtotal (cfs) = 4.47
No. Barrels = 1 Qpipe (cfs) = 4.47
n-Value = 0.013 Qovertop (cfs) = 0.00
Culvert Type = Circular Concrete Veloc Dn (ft/s) = 3.06
Culvert Entrance = Groove end projecting (C) Veloc Up (ft/s) = 4.59
Coeff. K,M,c,Y,k = 0.0045, 2, 0.0317, 0.69, 0.2 HGL Dn (ft) = 154.24
HGL Up (ft) = 154.08
Embankment Hw Elev (ft) = 154.43
Top Elevation (ft) = 154.83 Hw/D (ft) = 0.78
Top Width (ft) = 56.00 Flow Regime = Inlet Control
Crest Width (ft) = 12.00
Elev(ft) Single 18inch Culvert Ste 0+22 Sand Leaf Dr(025) H,.,Depth It
155.00 1.73
r
154.50 ��letrontrot 1.23
154.00 0.73
153.50 0.23
153.00 -0.27
152.50 -0.77
0 5 10 15 20 25 30 35 40 45 50 55 60 65 70 80 85
CircularCulvert HGL Embank
Reach(ft)

Culvert Report
Hydraflow Express Extension for Autodesk®Civil 3D®by Autodesk, Inc. Monday,Apr 29 2024
Single 24inch Culvert Sta 6+67 Sand Field Dr (Q10)
Invert Elev Dn (ft) = 152.43 Calculations
Pipe Length (ft) = 64.00 Qmin (cfs) = 7.95
Slope (%) = 0.30 Qmax (cfs) = 7.95
Invert Elev Up (ft) = 152.62 Tailwater Elev (ft) = (dc+D)/2
Rise (in) = 24.0
Shape = Circular Highlighted
Span (in) = 24.0 Qtotal (cfs) = 7.95
No. Barrels = 1 Qpipe (cfs) = 7.95
n-Value = 0.013 Qovertop (cfs) = 0.00
Culvert Type = Circular Concrete Veloc Dn (ft/s) = 3.14
Culvert Entrance = Groove end projecting (C) Veloc Up (ft/s) = 5.04
Coeff. K,M,c,Y,k = 0.0045, 2, 0.0317, 0.69, 0.2 HGL Dn (ft) = 153.93
HGL Up (ft) = 153.62
Embankment Hw Elev (ft) = 154.04
Top Elevation (ft) = 154.70 Hw/D (ft) = 0.71
Top Width (ft) = 56.00 Flow Regime = Inlet Control
Crest Width (ft) = 12.00
Eie,1ft Single 24inch Culvert Ste 6+67 Sand Field Dr(010) H,.,Depth It
15s.02 _[ 2.38
154.50 1.88
154.00 - / lilttrnntrnl 1.30
153.50 288
153.00 2 38
152.50 -0.12
152.00 -0.62
151.50 1 -1.12
0 5 10 15 20 25 30 35 42 45 50 55 60 65 70 80 85
CircularCulvert HGL Embank
Reach(ft)

Culvert Report
Hydraflow Express Extension for Autodesk®Civil 3D®by Autodesk, Inc. Monday,Apr 29 2024
Single 24inch Culvert Sta 6+67 Sand Field Dr (Q25)
Invert Elev Dn (ft) = 152.43 Calculations
Pipe Length (ft) = 64.00 Qmin (cfs) = 8.95
Slope (%) = 0.30 Qmax (cfs) = 8.95
Invert Elev Up (ft) = 152.62 Tailwater Elev (ft) = (dc+D)/2
Rise (in) = 24.0
Shape = Circular Highlighted
Span (in) = 24.0 Qtotal (cfs) = 8.95
No. Barrels = 1 Qpipe (cfs) = 8.95
n-Value = 0.013 Qovertop (cfs) = 0.00
Culvert Type = Circular Concrete Veloc Dn (ft/s) = 3.46
Culvert Entrance = Groove end projecting (C) Veloc Up (ft/s) = 5.25
Coeff. K,M,c,Y,k = 0.0045, 2, 0.0317, 0.69, 0.2 HGL Dn (ft) = 153.96
HGL Up (ft) = 153.69
Embankment Hw Elev (ft) = 154.15
Top Elevation (ft) = 154.70 Hw/D (ft) = 0.76
Top Width (ft) = 56.00 Flow Regime = Inlet Control
Crest Width (ft) = 12.00
Eie,itt Single 24inch Culvert Ste 6+67 Sand Field Dr(025) H,v Depth It
155.02 2.38
154.50 - 7 1.88
Islet control
154.00 - 1 36
153.50- eo
-,
153.00 2 38
152.50 -0.12
-:'
152.00 -0.62
151.50 -1.12
0 5 10 15 20 25 30 35 43 45 50 55 60 65 70 80 85
CircularCulvert HGL Embank
Reach(ft)

Culvert Report
Hydraflow Express Extension for Autodesk®Civil 3D®by Autodesk, Inc. Monday,Apr 29 2024
Dual 24inch Culverts Sta 7+56.5 & 7+51.5 Sand Field Dr (Q10)
Invert Elev Dn (ft) = 151.45 Calculations
Pipe Length (ft) = 40.00 Qmin (cfs) = 9.05
Slope (%) = 0.10 Qmax (cfs) = 9.05
Invert Elev Up (ft) = 151.49 Tailwater Elev (ft) = (dc+D)/2
Rise (in) = 24.0
Shape = Circular Highlighted
Span (in) = 24.0 Qtotal (cfs) = 9.05
No. Barrels = 2 Qpipe (cfs) = 9.05
n-Value = 0.013 Qovertop (cfs) = 0.00
Culvert Type = Circular Concrete Veloc Dn (ft/s) = 1.97
Culvert Entrance = Groove end projecting (C) Veloc Up (ft/s) = 4.22
Coeff. K,M,c,Y,k = 0.0045, 2, 0.0317, 0.69, 0.2 HGL Dn (ft) = 152.82
HGL Up (ft) = 152.24
Embankment Hw Elev (ft) = 152.52
Top Elevation (ft) = 153.89 Hw/D (ft) = 0.52
Top Width (ft) = 32.00 Flow Regime = Inlet Control
Crest Width (ft) = 10.00
Elev(ftj Dual 24inch Culverts Ste 7+56.5&7+51.5 Sand Field Dr(010) H„Depth ift:
154.00 z I I I I I I I ,E1
153.50 '_21
153.00 - 1 E l
152.50 ' _._ 1.21
152.00 .E 1
151.50 2.2 1
151.00 -0.4E,
150.50
0 5 10 15 20 25 30 35 40 45 50 55 60
CircularCulvert HGL Embank
Reach ift.

Culvert Report
Hydraflow Express Extension for Autodesk®Civil 3D®by Autodesk, Inc. Monday,Apr 29 2024
Dual 24inch Culverts Sta 7+56.5 & 7+51.5 Sand Field Dr (Q25)
Invert Elev Dn (ft) = 151.45 Calculations
Pipe Length (ft) = 40.00 Qmin (cfs) = 10.18
Slope (%) = 0.10 Qmax (cfs) = 10.18
Invert Elev Up (ft) = 151.49 Tailwater Elev (ft) = (dc+D)/2
Rise (in) = 24.0
Shape = Circular Highlighted
Span (in) = 24.0 Qtotal (cfs) = 10.18
No. Barrels = 2 Qpipe (cfs) = 10.18
n-Value = 0.013 Qovertop (cfs) = 0.00
Culvert Type = Circular Concrete Veloc Dn (ft/s) = 2.17
Culvert Entrance = Groove end projecting (C) Veloc Up (ft/s) = 4.38
Coeff. K,M,c,Y,k = 0.0045, 2, 0.0317, 0.69, 0.2 HGL Dn (ft) = 152.85
HGL Up (ft) = 152.28
Embankment Hw Elev (ft) = 152.59
Top Elevation (ft) = 153.89 Hw/D (ft) = 0.55
Top Width (ft) = 32.00 Flow Regime = Inlet Control
Crest Width (ft) = 10.00
Elev(ftj Dual 24inch Culverts Sta 7.56.5 8 7.51.5 Sand Field Dr(Q25) H6 Depth,ft:
154.00 2.51
ANN•ThIMO
153.50 2.01
153.00 1.51
152.50 Inlet control 1.01
152.00 0.51
151.50 0.01
151.00 -0.49
150.50 -0.99
0 5 10 15 20 25 30 35 40 45 50 55 60
CircularCulvert HGL Embank Reach(It)

4/17/24,3:06 PM Precipitation Frequency Data Server
NOAA Atlas 14,Volume 2,Version 3
":',7wR,� Location name:Saint Pauls, North Carolina,USA* '"'�'*"*
Latitude:34.8412°,Longitude: -78.893° E nonn
Elevation: 153 ft** I
°AN.°g " *source:ESRI Maps "w„* ,')
`8 " **source:USGS `'
POINT PRECIPITATION FREQUENCY ESTIMATES
G.M.Bonnin,D.Martin,B.Lin,T.Parzybok,M.Yekta,and D.Riley
NOAA,National Weather Service,Silver Spring,Maryland
PF tabular I PF graphical I Maps & aerials
PF tabular
PDS-based point precipitation frequency estimates with 90% confidence intervals (in inches/hour)1
Average recurrence interval(years)
Duration
1 2 5 10 25 50 100 200 500 1000
5-min 5.24 6.20 7.25 8.04 9.02 9.74 10.5 11.1 12.0 12.6
(4.80-5.77) (5.66-6.82) (6.61-7.97) (7.32-8.83) (8.18-9.88) (8.81-10.6) (9.40-11.4) (9.95-12.1) (10.6-13.1) (11.1-13.8)
10-min 4.19 4.96 5.81 6.43 7.19 7.76 8.30 8.81 9.48 9.96
(3.83-4.61) (4.53-5.45) (5.30-6.38) (5.86-7.06) (6.52-7.87) (7.02-8.48) (7.46-9.06) (7.88-9.61) (8.40-10.3) (8.77-10.9)
15-min 3.49 4.16 4.90 5.42 6.08 6.55 7.00 7.42 7.95 8.34
(3.19-3.84) (3.80-4.57) (4.47-5.38) (4.94-5.95) (5.51-6.65) (5.92-7.16) (6.29-7.64) (6.63-8.09) (7.05-8.67) (7.34-9.10)
30-min 2.39 2.87 3.48 3.93 4.50 4.93 5.36 5.77 6.33 6.75
(2.19-2.64) (2.62-3.16) (3.17-3.83) (3.58-4.31) (4.08-4.93) (4.46-5.39) (4.82-5.85) (5.16-6.29) (5.61-6.90) (5.94-7.37)
60-min 1.49 1.80 2.23 2.56 3.00 3.34 3.69 4.05 4.54 4.93
(1.36-1.64) (1.64-1.98) (2.03-2.45) (2.33-2.81) (2.72-3.28) (3.02-3.65) (3.32-4.03) (3.62-4.41) (4.02-4.95) (4.34-5.38)
2-hr 0.870 1.06 1.34 1.55 1.86 2.10 2.36 2.62 2.99 3.30
(0.785-0.979) (0.953-1.18) (1.20-1.50) (1.40-1.74) (1.66-2.08) (1.87-2.35) (2.08-2.63) (2.31-2.92) (2.61-3.34)_ (2.85-3.68)
3-hr 0.616 0.746 0.947 1.11 1.34 1.54 1.74 1.96 2.28 2.54
(0.556-0.695) (0.673-0.842) (0.853-1.07) (0.998-1.25) (1.20-1.51) (1.36-1.72)_ (1.53-1.95) (1.71-2.20) (1.97-2.55) (2.17-2.85)
6-hr 0.368 0.447 0.567 0.667 0.810 0.928 1.06 1.19 1.39 1.56
(0.333-0.413) (0.404-0.500) (0.512-0.634) (0.600-0.745) (0.722-0.901) (0.823-1.03) (0.929-1.17) (1.04-1.32) (1.20-1.54) (1.33-1.73)
12-hr 0.215 0.261 0.334 0.394 0.482 0.556 0.636 0.724 0.853 0.962
(0.194-0.242) (0.235-0.293) (0.299-0.375) (0.352-0.442) (0.427-0.538) (0.489-0.619) (0.555-0.707) (0.625-0.804) (0.725-0.947) (0.807-1.06)
24-hr 0.126 0.154 0.197 0.233 0.284 0.326 0.371 0.419 0.488 0.545
(0.117-0.138) (0.142-0.168) (0.182-0.215) (0.214-0.254) (0.259-0.310) (0.296-0.355) (0.335-0.405) (0.376-0.458) (0.434-0.534) (0.480-0.597)
2-day 0.073 0.089 0.113 0.133 r 0.161 0.184 0.209 ' 0.235 r 0.272 0.303
(0.068-0.080) (0.082-0.096) (0.104-0.123) (0.122-0.144) (0.147-0.175) (0.168-0.200) (0.189-0.227) (0.211-0.256) (0.242-0.297) (0.267-0.332)
3-day 0.052 0.063 0.079 0.093 0.112 0.128 0.144 0.162 0.187 0.207
(0.048-0.056) (0.058-0.068) (0.073-0.086) (0.086-0.101) (0.103-0.121) (0.117-0.138) (0.131-0.157)1(0.146-0.176) (0.167-0.204) (0.184-0.226)
4-day 0.041 0.050 0.063 0.073 0.088 0.100 0.112 0.126 0.144 0.159
(0.038-0.044) (0.046-0.054) (0.058-0.068) (0.068-0.079) (0.081-0.095) (0.091-0.108) (0.102-0.121) (0.114-0.136) (0.129-0.157) (0.142-0.174)
7-day 0.027 0.033 0.041 0.047 0.056 0.064 0.071 0.079 0.090 0.099
(0.025-0.029) (0.030-0.035) (0.038-0.044) (0.044-0.051) (0.052-0.061) (0.058-0.069) (0.065-0.077) (0.072-0.086) (0.081-0.098) (0.088-0.108)
10-day 0.022 0.026 0.032 0.037 0.043 0.048 0.053 0.059 0.066 0.072
(0.020-0.023) (0.024-0.028) (0.030-0.034) (0.034-0.039) (0.040-0.046) (0.044-0.052) (0.049-0.057) (0.054-0.063) (0.060-0.071) (0.065-0.078)
20-day 0.014 0.017 0.021 0.024 0.028 0.031 0.034 I 0.037 0.041 0.045
(0.013-0.015) (0.016-0.018) (0.020-0.022) (0.022-0.025) (0.026-0.030) (0.028-0.033) (0.031-0.036) (0.034-0.040) (0.038-0.045) (0.041-0.048)1
30-day 0.012 0.014 0.017 0.019 0.022 0.024 0.026 1 0.028 0.031 0.033
(0.011-0.013) (0.013-0.015) (0.016-0.018) (0.018-0.020) (0.020-0.023) (0.022-0.025) (0.024-0.028)f(0.026-0.030) (0.029-0.033) (0.031-0.036)
45-day 0.010 0.012 0.014 0.015 0.017 0.019 0.021 0.022 0.024 0.026
(0.009-0.011) (0.011-0.013) (0.013-0.015) (0.014-0.016) (0.016-0.019) (0.018-0.020) (0.019-0.022) (0.021-0.024) (0.022-0.026) (0.024-0.028)
60-day 0.009 0.011 0.012 0.014 0.015 0.016 0.018 0.019 0.021 0.022
(0.008-0.009) (0.010-0.011) (0.012-0.013) (0.013-0.014) (0.014-0.016) (0.016-0.017) (0.017-0.019) (0.018-0.020) (0.019-0.022) (0.020-0.023)
1 Precipitation frequency(PF)estimates in this table are based on frequency analysis of partial duration series(PDS).
Numbers in parenthesis are PF estimates at lower and upper bounds of the 90%confidence interval.The probability that precipitation frequency estimates(for
a given duration and average recurrence interval)will be greater than the upper bound(or less than the lower bound)is 5%.Estimates at upper bounds are not
checked against probable maximum precipitation(PMP)estimates and may be higher than currently valid PMP values.
Please refer to NOAA Atlas 14 document for more information.
Back to Top
PF graphical
https://hdsc.nws.noaa.gov/pfds/pfds_printpage.html?lat=34.8412&Ion=-78.8930&data=intensity&units=english&series=pds 1/4

4/17/24,3:06 PM Precipitation Frequency Data Server
PDS-based intensity-duration-frequency (IDF) curves
Latitude: 34.8412°, Longitude: -78.8930°
Average recurrence
10- ---- interval
(years)
10° - - �.� 2
(71 \ — 5
N — 10
c
— 25
o � — 50
m 10-1 - — 100
a \ — 200
,_a. \�`\`_ — 500
— 1000
10-2 -
r t t t I I t t I t t t I t I I I I
c c c c c t- t- t- I- " >. >.>1 >1 >+ >1 >1 >1>.
•E •E •E •E •� L L L L r0 r0 rr7 r0 N r0 r0 r0 r0
''' 4 m S Duration N N fr'1 4 r 2 N M v 8
101 - -- - — --
c
Duration
4' 10°
c - 5-min — 2-day
a
— 10-nin — 3-day
c 15-min — 4-day
0
— 30-min — 7-day
;° 10-1 — 60-rnin — 10-day
ii
— 2fir — 20-day
a` — 3-hr — 30-day
— 6-hr — 45-day
10-2 — 12-hr — 60-day
I t I t I t - 24-hr
1 2 5 10 25 50 100 200 500 1000
Average recurrence interval (years)
NOAA Atlas 14,Volume 2,Version 3 Created(GMT):Wed Apr 17 19:05:43 2024
Back to Top
Maps & aerials
Small scale terrain
https://hdsc.nws.noaa.gov/pfds/pfds_printpage.html?lat=34.8412&Ion=-78.8930&data=intensity&units=english&series=pds 2/4

4/17/24,3:06 PM Precipitation Frequency Data Server
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100km
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Large scale map
rvmsronoaem Greensboro Durham
Rocky Mount
Raleigh
North Greenville
Carolina
0 arlotte
• F etteville
.�
• Jacksonville
0
Wilmington +
o
• mbia _
,out 100km
:a I
60mi
Itzr
Large scale aerial
https://hdsc.nws.noaa.gov/pfds/pfds_printpage.html?lat=34.8412&Ion=-78.8930&data=intensity&units=english&series=pds 3/4

4/17/24,3:06 PM Precipitation Frequency Data Server
Greensboro Durham . Rocky Mount
Raleigh
• Greenville
North •
Carolina
Charlotte
• Fayetteville
• Jacksonville
Wilmington
•
Cdumbia
so 100km
Carc
60mi
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US Department of Commerce
National Oceanic and Atmospheric Administration
National Weather Service
National Water Center
1325 East West Highway
Silver Spring,MD 20910
Questions?:HDSC.Questions(c�noaa.gov
Disclaimer
https://hdsc.nws.noaa.gov/pfds/pfds_printpage.html?lat=34.8412&Ion=-78.8930&data=intensity&units=english&series=pds 4/4

Appendices
3 . , . I Ii I Ill:
Outlet W = Do + La 90 ' 'on II 1 ' in i1
i, mum "I
pipe
., I liii iilll�l 1 ' i.
I
HH1u1 1
diameter (Do) uuun�l=� I . I;�`i
La —'i mum • I M
80 { f_ IIIIIIIIII ., 11;!1' I'
T ilwater < 0.5Do _,. -._ _. � .. �uuH1 , N1'I'll'll' P
I_ — _ _-- i_ 111111 IA%%Al'.
��1, 7C III ,, 1/140f111' I
a _ lir dllailil' I
O(� — 41Ij11 toi, .a Il�I
p.P� 60 It• - II ' --*Jr/Ally/Aliy ''I OHIO
O 1 0 4/II!ili/11 .1 • II■I
O�ir MEMO. :Ti el. '/I P iI'il •• , , 1111111
ii:lPn s uu1■:1.
Ve �1 !! -_-_ y /'1 II rlli, 111111I1 1
v(� 5 1 I ■■ r •A/ II • 111111111II11111■I
�� 2_;-- -- _ • Fir* vllauuunum
0\n - I= o a%p or ►niiiii imunlnm■
h IHHdum nut uuuu
PP: RI_ -I_l • r I11111111■111111:1111111•.,
40 III_ -ai• r%r►,��I�IIIIIII■p IIP.,,Illrll
II-_ - ��� I�IIIIIIII dldllll�
H .-- -- __ .. �/ I�IIIIIIIII A111S 1111-
III 4 _ k iI �1�11ru11111111 1111111'A'I11 '
��nn III - • 'i/illl�d 1 11m11111111111111111AKII
N. 1111 _ 1. /' , ��i MI11111111 IIIIP'e11'IIIID1
I III H-- '/�`� i/ �—� 1 4•iIJIII;IP.'d
I IIIm� F-- _ " 1�1 ...% 1�� 111 IlI ,IIIISIIP'•iiP/:
I IIIA■� 1d .,.�/ di PM ...r111H'IDI
20 ��■� 1 H�� , 15 .i:/. L�LAI II= 1=1 rlliiIIIMP!;nP lull. 3
m_■I_iM iIf.1. ? Iil 'iIllit -- — - u II Ill 1 il!1l;n'*,��a`'
10 =!.':_Ir�mIN mil 'I'4�r Ifc7,d;
lli
Il111 / i r715!:;A11111:11:111i 1 --
0 ���11111111111.111
I �! ► III;IIIII,111i1!ll! •' 2
=� '1 —,� law IiI[iII uluaSIR111� tI■ .-
LFIIP'111/P1•„�Illi
—I �� r. I! ,bIn1II': A:11:11!:]IIIII•I 0-
MI'NEI I�� ',Ara di iii iii
,i �_siI■��':llnsnilmnnn�lnul as
8_
Minnv='' /•�,i� �.c�' 1�ialr.,nummnnn1111■
.— 11 - - ,` III_ [l!n,' 0�i 1' -. Y Ir .I�Ilunnulmmmuull m
- • �M1 IUUIIIIIIIIIIIIIIIIIIIIIIIIwI
_ �� •'I �1 1 IHHHmn1 mmum■
% ' 1 a— - - -- ''-- - ' ',5 - . �/..4 / II ii1IllHUIM '
�I v=
5 fps I ; II !
II Ii l:l' ;
' I I • � I -I I I I I I .I' II ,I Ill 0
3 5 10 20 50 100 200 500 1000
Discharge(ft3/sec)
Curves may not be extrapolated.
Figure 8.06a Design of outlet protection protection from a round pipe flowing full,minimum tailwater condition(Tw<0.5 diameter).
18" CULVERT RIP RAP APRONS
L=9' W= 14' THICKNESS = 18" d50=8" Class B
Rev.12/93 8.06.3

Appendices
3 0 . , . I ll 1 1,!:
Tip
Y. ,I l II.iI'.
Outlet W = Do + La 90 'iin iin 1 ' III
j. IIII IIIII 1
pipe ;nll�u■111 �,
diameter (Do) 1 iiiiiiri�i=�� I
80 1111111111111 �i&Af";'1
La —'i i -f- - ,. _ uWum * fl;!ililLll
1 _ IIIIIIIIIII �f,!d.1Al'I
T ilwa___ < 0.5Do - -,..- - --- --._ _. -_ '-- Iuuu1 N iIr!P 1''r
I-- — — 6 111111 '�:I�illlilil �'
��1 7C in * All'Al!111' I
,,,,,co - - -- --- - -_' - _ - 1 _ , ,'/,d;lil►,I,m Suu
P 60 I _ �AC11 P 5115 'I •'iIII
O _ /.111!ill//1 .1 • 1111
�`� it I _ E1 ph. 7 1i;i .• . , 111111
egg — ; - r__ y r aril, 5 uuul
-- - - 1i roi, nnml
J 5 6 'Ji roil/111111111111
\(� 2_;-- -- _ I ,, ' / IIII/111111111111111
`h A - 1-..� 7r# aidiiiir 111I1lIm iIIII p
IIIIIIIIIIII 1111 IIIIIIII,
/�' 11111111um. midi 4
40 iisr_rS�luuullu ,DA.,,IIII►I/1111111 iIP1111'llA i Iuuuu ni, nu:n ,
-_ =Ilk
- "s 1:MIN I J I
' /1111111 1111111S1111 .41 1
��nn ' %"I / I � IIIII IIIIIIIIIIISIV!;IIIII
_9. I . ., ,Tor .•ri 1111111 UIIP:i iriiii11.•
I -+--- 4 csI / _ �—�� 4.'i1JI11;IP!'il 1
��� ■ ill IJIpi11111.
1L
I !I_ ■ 11111 :iuiiuSI20 ! 1I- 1.6 ../:il l 1 ■ rdiiliu i ii u1elrl i
��--JIB Z — , /�'OR -- ■ ,I111111III•lIl & rI 3
_� /.mot � l u_ I%I�11 IIiJ ,li, �.
m .0!:;41111;1Pillvi a)
�� — • / / rlllll!i111/11:Ilill�i N
0 �1•� IiU111uIi I' III;IIIII,IIIiI�!ll! 2il —
_,� piaI�� �F;11111.11:11;11�� d
�� � rt — �,, .ram i11!;11 1!111111111111111
�' - — 4= ' i/.iI /aIIISiI11I111111I111111i1111111111111111111 —
- Ff li l!n, ' —ry Ar �Ilunnulnuumuuullcc
M� --- i. • a! ii Ilunuuuuunuuuul o
' ,�1,�� liiiiiiiiiiiii��iiiiiiiiiiii
_ �N�"'.. /��. �= flIIi1UfflJ!
1
v_,0 .d I11.'
li
•v s 1. —�" 11111 .l,11 0
3 5 10 20 50 100 200 500 1000
Discharge(ft3/sec)
Curves may not be extrapolated.
Figure 8.06a Design of outlet protection protection from a round pipe flowing full,minimum tailwater condition(Tw<0.5 diameter).
24" CULVERT RIP RAP APRONS
L= 13' W= 18' THICKNESS = 18" d50=8" Class B
Rev.12/93 8.06.3

Appendices
3 0 . , . I lI l 1,':
,Y. I r in IIl r II.1I'.
Outlet W = Do + La 90. ' 'mum I '' in
'1, mum pipe ;IIIIIIIIII�1 �,
diameter (Do) 1 nimbi.. I '
80 IIIII1111m .ii,;i 1i'1
La —'i f- - +. _ uulum * fl;!i1 ri
1 _ IIIIIIIIIII *Agri!
T ilwa__ < 0.5Do - -,..- - --- --._ _. -_ '-- Iuuu1 i.11r! lrlcr
I-- — — 6 IIIIII '�:It'llllili' �'1
��1 7C III * All'AP111' • I
P 60ric° I _ �./A IIIl;15o5 'I •11I
/.III!,11//4 .1 • 11111
�`� it 1 _ E1 ph. r IS1ri1 .• . , 111111
eYg ; y r aril, s u11111
-- - . �i ri, nnml
J 5 6 'Ji roil 1111111111111
\(� 4_;-- -- _ I ,, / Ir11411111111111111 B
0\� - I .. _I _O a I' Id p11111111111I11111111
h A - I-..fi r 11A111111111111111111111
i 1lunuun Iiiiiiimmiuu 1111II1�lip;iiii
40 111111L--I'
iisr_rS�luuullu ,DA.,,IIII►I
tr /1111111 iIPd111I'll
..--/ IIIIIIIII iI11' IIICII
' IIIII III IIIIIIPAIIIIJ:i(I
N. '�%"I / r II111111111r1111i1M AIII
Y. I - 1 �■i 1111111 1111P:;AI'II III.•
IL
M it ' �I //%� _ F—L� 4.'i1JI11;iP!'il 1
� , ■ ill IJIpilllll.
20 ��■! I � 1.6 ../:il l IA I ■ Idiilivai ii 111MIN 1
�--JIB 2.'.-
_ , /�' -- ■ _ — ,IIIllll:ii•lIl & , rI 3
�_L /.mot � 1 —- _ u_ I! 11' RiJ ,Dli, v
10 �■w:�r.i _
m�� —- • / / • rllll!i111/11:Ilill�i N
0 ��� IiU111uIi I' III1-41,1111Pi11! 2 -
_,� aI�� --...F 11.11.Ire�nl cn
��MO min 111_Iorro.A / ' ,�ilil1A11:11!:]IIIIIIi
�' _ _ V= �l '/ •alll,111111111111111111111 -
as
.40 Eli-1!:ilitiihiiiiIIIIIIIIIIii -
Mil
}l li_.l'n, �iy Ar. nunnlllllluumuuull oC
�� --- i- .• t IIIIIIIIIIIIIIIIIIIIIIIIIII o
v' r1,�� liiiiiiiiii��iiiiiiiii
i . ���'.'.._. /��� �M flIIi1UfflJ!
1
li
vs —1" • • .l,11 0
3 5 10 20 50 100 200 500 1000
Discharge(ft3/sec)
Curves may not be extrapolated.
Figure 8.06a Design of outlet protection protection from a round pipe flowing full,minimum tailwater condition(Tw<0.5 diameter).
2' TRAPEZOIDAL OUTLET SWALE RIP RAP APRON
L= 13' W= 18' THICKNESS = 18" d50=8" Class B
Rev.12/93 8.06.3

Soil Map—Cumberland County,North Carolina
9 (Rufus Johnson Rd) M
M
692350 692400 692450 692500 692550 692600
34°50'28"N 34°50'28"N
0
,§
k
N
1
G
0
AuA
/*%:\„. •
^1
0
N;':\ ' • '
\10 , •'%,
0 0�
0 :, pi'
§ a000 Gawp yu-ii oR bQ umi 70 tcGfuo Aa0b°
R • .s►!,,,, :4 • §
34°50'15"N ♦ _�- - 0 34°50'15"N
692350 692400 692450 692500 692550 69.2600 692650
3 3
1
M Map Scale:1:1,980 if printed on A portrait(8.5"x 11")sheet.
Meters
A
N 0 25 50 100 150
Feet
0 50 100 200 300
Map projection:Web Mercator Corner coordinates:WGS84 Edge tics:UTM Zone 17N WGS84
USDA Natural Resources Web Soil Survey 4/23/2024
aria Conservation Service National Cooperative Soil Survey Page 1 of 3

Soil Map—Cumberland County,North Carolina
(Rufus Johnson Rd)
MAP LEGEND MAP INFORMATION
Area of Interest(AOI) Spoil Area The soil surveys that comprise your AOI were mapped at
Area of Interest(AOI) 1:24,000.
Q Stony Spot
Soils Very Stony Spot Warning:Soil Map may not be valid at this scale.
0 Soil Map Unit Polygons
Wet Spot Enlargement of maps beyond the scale of mapping can cause
.�� Soil Map Unit Lines misunderstanding of the detail of mapping and accuracy of soil
Other line placement.The maps do not show the small areas of
p Soil Map Unit Points contrasting soils that could have been shown at a more detailed
Special Line Features
Special Point Features scale.
(9 Blowout Water Features
Streams and Canals Please rely on the bar scale on each map sheet for map
cs Borrow Pit measurements.
Transportation
X Clay Spot Rails Source of Map: Natural Resources Conservation Service
0 Closed Depression Web Soil Survey URL:
ti Interstate Highways Coordinate System: Web Mercator(EPSG:3857)
X Gravel Pit US Routes
Maps from the Web Soil Survey are based on the Web Mercator
,. Gravelly Spot Major Roads projection,which preserves direction and shape but distorts
distance and area.A projection that preserves area,such as the
0 Landfill Local Roads Albers equal-area conic projection,should be used if more
Lava Flow accurate calculations of distance or area are required.
Background
46 Marsh or swamp Aerial Photography This product is generated from the USDA-NRCS certified data as
of the version date(s)listed below.
iRk Mine or Quarry
Soil Survey Area: Cumberland County,North Carolina
O Miscellaneous Water Survey Area Data: Version 25,Sep 13,2023
Q Perennial Water Soil map units are labeled(as space allows)for map scales
v Rock Outcrop 1:50,000 or larger.
▪ Saline Spot Date(s)aerial images were photographed: Apr 11,2022—May
15,2022
Sandy Spot
The orthophoto or other base map on which the soil lines were
Severely Eroded Spot compiled and digitized probably differs from the background
imagery displayed on these maps.As a result,some minor
• Sinkhole shifting of map unit boundaries may be evident.
3) Slide or Slip
oa Sodic Spot
i\ Natural Resources Web Soil Survey 4/23/2024
Conservation Service National Cooperative Soil Survey Page 2 of 3

Soil Map—Cumberland County, North Carolina Rufus Johnson Rd
Map Unit Legend
Map Unit Symbol Map Unit Name Acres in AOI Percent of AOI
AuA Autryville loamy sand,0 to 2 10.6 99.7%
percent slopes
Ra Rains sandy loam,0 to 2 0.0 0.3%
percent slopes
Totals for Area of Interest 10.6 100.0%
USDA Natural Resources Web Soil Survey 4/23/2024
Conservation Service National Cooperative Soil Survey Page 3 of 3

4
, ,
N
4.
%I.
r • •
4.
JDA NA.
500 LF
l
j ::
DER OF
CELS PA
`,
DP-10 NonJDFarm PonAc.
. V-
A. .0%,li
;IP , . / ti)0
•
At, ) . '' '
1
!
. t . 4 i . - 0,-, .7i1L:. .: ' .. ... I: ''.• '4.- N'A(Pl'. ' '4:
4' • PREVIOUSLY PLATTED
t SUBDIVISION ALONG
r'T" RUFUS JOHNSON RD
1, .`_
I r i , .- TRI-COUNTY
• ^� ' t SUBDIVSION'S EXTENTS
• - LEGEND
7 •
Site Boundary
V1
•
"vim - _ ---- Potential Jurisdictional Non-Wetland Water
, -r J 7.i. .' Itleito ;'"
J" C 7 Non-Jurisdictional Upland Excavated Farm Pond
THE LOCATIONS OF FEATURES SHOWN ON THIS MAP ARE PRELIMINARY. SA 1-5 Feature ID/Flag Number
THEY HAVE NOT BEEN VERIFIED BY THE USACE. THIS MAP INCLUDES GPS
LOCATIONS OF DELINEATED FEATURES. DELINEATED BY PILOT ON 2.28.24. DP-1 0 Data Point
s
Drawing 5 Wetland Map
Aerial Imagery from ESRI , - �� -� Approximate 30-Acre Tract
and Pilot GPS Data __ _ .� y' Chicken Foot Road
Scale: 1" = 300' PILC,'. St Pauls, Cumberland County, NC
Date: 3.5.2024 PILOT ENVIRD , M!NTAL,INC Pilot Project10707