SW6191004_PN_95396_Multipurpose_Training_Facility_SWM_and_ES_Calcs_Narrative_11/7/2019

CIVIL CALCULATIONS
SOTF Multipurpose Training Facility
PN 95396
The civil calculations attached are for the storm water management and erosion
and sediment control analysis.
100% Submittal: 12 July 2019
Prepared by:
5 Stantec
Stantec Consulting Services Inc.
801 Jones Franklin Road, Suite 300
Raleigh, North Carolina, 27606
[phone] //Fax [phone]
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TABLE OF CONTENTS
Sediment Erosion Control and Stormwater Management Project
Narrative....................................................................................................................01
NRCS Report..............................................................................................................03
EISA Section 438 Calculations.................................................................................07
Rip -Rap Outlet Protection Sizing............................................................................16
Water Quality Volume Calcs...................................................................................18
Channel Sizing and Velocity Calcs..........................................................................23
DrainageArea Maps................................................................................................28

Ft. Bragg, SOTF Multi -Purpose Training Facility Project
Sediment Erosion Control and Stormwater Management
Narrative
The proposed project known as Fort Bragg SOTF Multi -Purpose Training Facility
project consists of a new concrete training facility along with access/maintenance
roads, and storm drainage. The new training structure is similar to a walk -out
basement in terms of grading and access app asphalt parking lot, concrete pavement,
and stormwater management infiltration basin #1 - #2. This report presents the
sediment and erosion control and stormwater management calculations for the project.
The property is located on Fort Bragg in Cumberland County, North Carolina with
access to the site from Lamont Road. The project is located in the north/northwest
portion of the compound. The scope of work for the project includes civil site work
and minor electrical site utilities design along with clearing and grubbing of existing
trees.
The project is located in a wooded area on the north side of a crowned highpoint which
drains primarily to the north and east with a smaller share of drainage to the southeast.
The site consists primarily of hydrologic Group A soils (see NRCS report) which has
been corroborated with favorable infiltration rates (3.3 in/hr and 2.02 in/hr—see
geotechnical report submitted under separate cover).
SEDIMENT AND EROSION CONTROL
The site sits on a crowned high point with gradual slopes typically less than 6% within
the limits of disturbance (LOD). The primary disturbance activity for the construction of
the facility will be excavation; therefore, the primary means of sediment leaving the site
will be within storm drain systems and in the initial stage of clearing and utility
trenching. The perimeter is protected with a combination of sediment fence, J-hooks,
and sediment fence outlets. The storm drain system will use inlet protection and rip -rap
outlet protection to prevent sediment laden water from leaving site. There is only one
point of entry/exit to the site where a temporary construction entrance/exit is located
(the western most edge of the LOD). A concrete washout station is also provided near
the entrance/exit. All stormwater facilities will be constructed last, once all drainage
areas have been stabilized.
STORMWATER MANAGEMENT
The site has been broken down into two main drainage areas (one for each infiltration
trench) for the purposes of determining the required stormwater management volume
requirements for each infiltration basin. The site has been graded to capture all the
impervious areas either in storm drain systems or surface flow via swales and sheet
flow. The impervious areas consist mainly of the concrete roof/pad of the training
facility and the maintenance/crane access road which is comprised of 12 inches of
NCDOT #4 washed stone laid on geotextile fabric. The northwestern portion of the site
Page 1 of 29

is captured primarily through a storm drain network with false sumps at manholes with
grated inlet tops. This network outfalls to an infiltration trench: SWM#2. The
northeastern portion of the site enters SWM #2 via sheet flow. The southeastern
portion of the site primarily enters SWM#2 via a small swale with a small portion
entering via an inlet which drains via 15" RCP (Gov. mandated minimum pipe size) to
an outfall. The southwestern portion of the site drains to a SWM#1, an infiltration
trench, which is a graded as a false sump. A rock weir overflow was designed for this
facility to channel the water through a specific part of the berm such that the overflow
would not enter the channel leading to SWM #2.
Due to the nature of the site (heavily wooded and training activities), the
facilities have been oversized to ensure longevity and prevent stormwater
issues at the site.
Page 2 of 29

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Page 4 of 29

Hydrologic Soil Group —Cumberland County, North Carolina
Soil Map -
Hydrologic Soil Group
Map unit symbol
Map unit name
Rating
Acres in AOI
Percent of AOI
BaB
Blaney loamy sand, 2 to
8 percent slopes
C
1.0
11.3%
BaD
Blaney loamy sand, 8 to
15 percent slopes
C
0.2
1.9%
TR
Torhunta and Lynn
Haven soils
A/D
0.7
8.1 %
WaB
Wagram loamy sand, 0
to 6 percent slopes
A
6.9
78.6%
Totals for Area of Interest
8.8
100.0%
Description
Hydrologic soil groups are based on estimates of runoff potential. Soils are
assigned to one of four groups according to the rate of water infiltration when the
soils are not protected by vegetation, are thoroughly wet, and receive
precipitation from long -duration storms.
The soils in the United States are assigned to four groups (A, B, C, and D) and
three dual classes (A/D, B/D, and C/D). The groups are defined as follows:
Group A. Soils having a high infiltration rate (low runoff potential) when
thoroughly wet. These consist mainly of deep, well drained to excessively
drained sands or gravelly sands. These soils have a high rate of water
transmission.
Group B. Soils having a moderate infiltration rate when thoroughly wet. These
consist chiefly of moderately deep or deep, moderately well drained or well
drained soils that have moderately fine texture to moderately coarse texture.
These soils have a moderate rate of water transmission.
Group C. Soils having a slow infiltration rate when thoroughly wet. These consist
chiefly of soils having a layer that impedes the downward movement of water or
soils of moderately fine texture or fine texture. These soils have a slow rate of
water transmission.
Group D. Soils having a very slow infiltration rate (high runoff potential) when
thoroughly wet. These consist chiefly of clays that have a high shrink -swell
potential, soils that have a high water table, soils that have a claypan or clay
layer at or near the surface, and soils that are shallow over nearly impervious
material. These soils have a very slow rate of water transmission.
If a soil is assigned to a dual hydrologic group (A/D, B/D, or C/D), the first letter is
for drained areas and the second is for undrained areas. Only the soils that in
their natural condition are in group D are assigned to dual classes.
USDA Natural Resources
Conservation Service
Web Soil Survey
National Cooperative Soil Survey
2/12/2019
Page 3 of 4
Page 5 of 29

Hydrologic Soil Group —Cumberland County, North Carolina
Soil Map
Rating Options
Aggregation Method: Dominant Condition
Component Percent Cutoff.- None Specified
Tie -break Rule: Higher
USDA Natural Resources
Conservation Service
Web Soil Survey
National Cooperative Soil Survey
2/12/2019
Page 4 of 4
Page 6 of 29

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Page 7 of 29

LAND USE
To calculate the EISA runoff requirement enter the pre- and post -project land use in acres
The runoff volume difference between pre- and past -project is the Z A volume required to be retained on site -
Note: If the runoff di f'erence is a negative number, the post -project rolume is reduced horn the pre -project condition and no additional retention volume is reTlkm
Land Use
Wooded (poor):
Wooded (fair):
36
Pre -project Pexcentag-e
iu acres of site
0 4
0 0
Post -project Percentage
area in acres of site
4
0
Runoff volume calculations
-pre--project Post -project Dffere
mite CN: 30 61
Wooded (good):
30
65 100
3aO
0 0
Acre-feet: 0-000 0-012 0-01 t
Meadow:
39
0
0 0
Gallons: 0 3895 3895
Brush and weeds (poor):
48
0
0 0
Cubic feet: 0 521 321
Brush and weeds (fair):
35
0
0 0
US: 0-00 0-01 0.01
Brush and weeds (good):
0
0 4
51 cubic feet is the EIA runoff
Lavin:
49
0
2-771 75-9
volume required to be retained
Roads and drives (wlo C and G):
83
0 0
0 0
on site.
Roads and drives (wf C and G):
98
0 0
0-563 13-4
Parting, driveways and sidewalks:
98
0 0
0 o
Building roof:
gg
0 0
0.316 8.66
Bare soil:
0 0
0 0
Trees - grassy (poor):
0 0
0 0
Trees - grassy (fair):
43
0 0
0 0
Trees - grassy (good):
32
0 0
0 0
Open space (lawns, parks, cem-) <50%
68
0 0
0 0
Open space (lams, parks, cem-) <75%gr
49
0 0
0 0
Open space (lawns, parks, aem-) >75%9grass:
39
0 0
0 0
Gravel road:
Dirt road: MA
TOTAL LIMIT OF DISTURBANCE = 3.65
Page 8 of 29

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Page 9 of 29

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Page 10 of 29

1-bite Info 2--Runoff FBioretention wale Permeable Pavement Rainwater Harvesting Green Roof Infiltration Practice Water Quality
LAND USE
To calculate the EISA runoff requirement enter the pre and post -project land use in acres
The runoff volume difference between pre- and post -project is the E15A volume required to be retained on site -
Note: IF the runoff difference is a negative number, the post -project r-olume is reduced from the pre -project condition and no additional retention r-olume is required -
Land Use pro Percentage P°st-pF°1 Runoff volume calculations
of siteres��� area in acres
V4�oaded ( oar)- �
Avirm
Prepr4tect host protect Diere�
r
Wooded (fair):
Wooded (good):
Meadow:
Brush and weeds (poor):
Brush and weeds (fair):
Brush and weeds (good):
Lavin:
Roads and drives (wlo C. and G):
Roads and drives (wl C. and G):
Parking. driveways and sidewalks:
Building roof -
Bare soil:
Trees - grassy (poor):
Trees - grassy (fair):
Trees - grassy (good):
Open space (lawns, parks, cem-) <50%
Open space (lawns, parks, cem-) <75%
Open space (lawns, parks, cem-) >75%
Gravel road:
Dirt road:
IEel I/_141ILTA IIIto] a0lF-Ilhlilk] 1-00to] ; Me]11-Y)
Page 11 of 29

Page 12 of 29

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Page 13 of 29

Multi -Purpose Trainer
W7/10/2019
UP N 95396
1+IT1�I View C' t Pie�v Repork Add PYojec# I Delete Project � Retention volume pro,, i
+ 0
1-bite Info 2-Runoff Bi retentian I Swale Permeable Pavement Rainwater Harvesting Green Roof Infiltration Practice Water Quality
L.AN D USE
To calculate the ESA runoff requirement enter the pre- and post -project land use in acres
The runoff volume difference between pre- and post -project is the EISA volume required to be retained on site_
Note: IF the runoff difference is a negative number, the post-projEct volume is reduced from the pre -project condition and no additional retention vol
_AL_ _AL_
Land We Pre -project Percentage Past -project. Peroenta Runoff volume calculations 'Eq
in acres Of site area in acres Of sitePW dn � Pr,—pnaJeet Post pra}ect Dierence
Wooded (poor): 45 0 0 0
Wooded (fair): 36 0 0 0 Site C: 30 63 41
Wooded (good): 30 2.25 0 0 Acre-feet: 0.000 0.011 0.011
4leadow: 39 0 0 0 0 Gallons: 0 3677 3677
Brush and reeds (poor): 48 0 0 0 0 Cubic feet: 0 492 492
Brush and reeds (fair): 35 0 0 0 0 CFS: 0.00 0.01
Brush and weeds (good): 30 0 0 0 0 IP
492 cubic feet is the EI SA runoff'
Lavin: 49 0 1.63 72.4
volume recjuired to be retained
Roads and drives (w/o C and G): 83 0 0 0 on site.
Roads and driyes (w/ C and G): 98 0 0 0
Parking, driveways and sidewalks: 9130 0 0 0.3 5 S 1 S_ 9
Building roof- 99 0 0 0.262 11.6
Bare soil: 0 0 0 0
Trees - grassy (poor): 57 0 0
Trees - grassy (fair): 43 0 0 0
Trees - grassy (good): 32 0 0 0 0
Open space (lawns, parks, cem_) <50%grass: 68 0 0 0 0
Open space (lawns, parks, cem-) <75%grass: 49 0 0 0
Open space (lawns, parks, cem-) >75% a
39 0 0 0
Gravel road: 0 0
Dirt road: 0 0
TOTAL LIMIT OF DISTURBANCE = 2.25
Page 14 of 29

Page 15 of 29

—
DATE
20190703
DESIGN PHASE
PRELIM
CONSTR
REVISION
RECORD
OTHER
(SPECIFY)
/ X /
PROJECT NAME
Multipurpose Training Facility
P70-77M 0
178451232
Fort Bragg, NC
MTB
UHLUKLU BY
UL5
Storm Outlet Structure - A7
FES No.=
A7
Pipe Dia=
15
in
Q 10 =
2.76
cfs
Qfull =
4.52
cfs
Vfu l l =
3.7
fps
From Fig. 8.06.b.1:
From Fig. 8.06.b.2:
Zone
D50
DmAx
Riprap Class
Apron Thickness
Apron Length
Apron Width = 3xDia
Storm Outlet Structure - B2
FES No.=
B2
Pipe Dia=
15
in
Q 10 =
2.64
cfs
Qfull =
4.80
cfs
Vfu l l =
3.90
fps
From Fig. 8.06.b.1:
From Fig. 8.06.b.2:
s
3
Length
Zone
Dso
DmAx
Riprap Class
Apron Thickness
Apron Length
Apron Width = 3xDia
Q10/Qfull = 0.61
V/Vfu I = 1.05
V = 3.8 fps
= 1
= 4 in
= 6 in
= A
= 12 in
= 5 ft
= 4 ft
Q10/Qfull = 0.55
V/Vfu I = 1.02
V = 4.0 fps
= 1
= 4 in
= 6 in
= A
= 12 in
= 5 ft
= 4 ft
Page 16 of 29

' ' • •
DATE
20190703
DESIGN PHASE
PRELIM
CONSTR / X /
REVISION
RECORD
OTHER
(SPECIFY)
PROJECT NAME
Multipurpose Training Facility
PROJECT NO
178451232
LOCATION
Fort Bragg, NC
BY
MTB
CHECKED BY
DLS
Storm Outlet Structure C-1 and C-2
FES No.= *N/A
Pipe Dia= 12
in
Q 10 = 2.84
cfs
Qfull = 3.56
cfs
Vfu l l = 4.53
fps
From Fig. 8.06.b.1:
Zone
From Fig. 8.06.b.2:
D50
DMAX
Riprap Class
Apron Thickness
Apron Length
Apron Width = 3xDia
*Culvert Projecting from Fill
Q10/Qfull = 0.80
V/Vfu I = 1.11
V = 5.0 fps
= 1
= 4 in
= 6 in
= A
= 12 in
= 4 ft
= 3 ft
Page 17 of 29

10/3/2019
NCDEQ BMP Manual
INFILTRATION BASIN #1 & #2
1.0" Water Quality Volume (WQv)
(ACTUAL DRAINAGE AREA TO SWM DEVICE)
Rv = runoff coefficient (Runoff/Rainfall)
Rv = 0.05 + 0.009(I) Where "I" = % Impervious
("Simple Method" - Schueler, 1987)
WQv = 1.0"RvA
12
Infiltration Basin #1
Fill in Values:
tO.259 DA Impervious Area (Ex. & Prop.)
"I"= 4 Percent Impervious of DA
"A" = *DA (Acres)
*Offiste area = 4,261 SF
Answer:
WQv = 0.022 Ac. Ft.
976 Cubic Feet Required
2,244 Cubic Feet Provided
Infiltration Basin #2
Fill in Values:
0.606 DA Impervious Area (Ex. & Prop.)
"I" = T7.3409J Percent Impervious of DA
"A" = 2.215 *DA (Acres)
*Offiste area = 6,045 SF
Answer:
WQv = N
Ac. Ft.
Cubic Feet Required
Cubic Feet Provided
= 11 282 SF impervious area
A = Actual Drainage Area to SWM Device
Rv= 0.374732
WQv= 0.37 inches
CN(WQv)= 91.4 Use to comp. Qj--
= 26 380 SF impervious area
A = Actual Drainage Area to SWM Device
Rv= 0.296068
WQv= 0.30 inches
CN(WQv)= 89.3 Use to comp. Qj--

Infiltration Basin #1
SA = DV
(K/12/FS*T)
DV= 2,244.40 cu ft
K= 3.30 in/hr
FS= 2
T= 72 hrs
Min. Surface Area (SA) = 227
Surface Area Provided = 1 724
Infiltration Basin #2
SA = DV
0.718 *DA (Acres (K/12/FS*T)
DV= 2,684.63 cu ft
K= 2.02 in/hr
FS= 2
T= 72 hrs
Min. Surface Area (SA) = 443
Surface Area Provided = 1,391

NC DEQ Draw Down Time:
Infiltration Basin #1
Total Volume (Exluding Surface Storage):
2,244 cu.ft.
Infiltration Bottom Area:
724 sq ft.
Maximum Release Time:
72 hrs
Overflow Berm Elev:
244.50
Bottom of Basin:
1 243.00
Infiltration Rate:
1 3.30 in/hr (Boring 1-02)
Factor of Safety (FS):
1 2.00
Bottom of Infiltration Basin Elev:
243.00
Draw Down Time for only Infiltration with FS: 23 hrs OK
Infiltration Basin #2
Total Volume (Exluding Surface Storage):
2,685 cu.ft.
Infiltration Bottom Area:
1,391 sq ft.
Maximum Release Time:
72 hrs
Overflow Elev:
224.10
Bottom of Basin:
1 223.77
Infiltration Rate:
1 2.02 in/hr (Boring 1-01)
Factor of Safety (FS):
1 2.00
Bottom of Infiltration Basin Elev:
223.77
Draw Down Time for only Infiltration with FS: F 23 hrs OK

DRAINAGE AREA & IMPERVIOUS AREA
Pre -Development Impervious Area (Within Drainage Areas) Infilt #1 0 SF
Infilt #2 0 SF
Post Development Impervious Area (Prop. & Ex.) (Within Drainage Area)
Infilt #1
11,282 SF
Infilt #2
26,380 SF
Post Development Impervious Area (Prop. & Ex.) (Excudes Gravel)
Infilt #1
2,352 SF
Infilt #2
10,785 SF
Project Limit of Disturbance (Using as Project Area)
LOD
158,994 SF
Pre -Development Impervious Area (Within LOD)
LOD
0 SF
Post Development Impervious Area (Prop. & Ex.) (Within LOD)
LOD
37,662 SF
Post Development Impervious Area (Prop. & Ex.) (Excludes Gravel)
LOD
13,137 SF
1.0" Volume For Project Area (LOD) Using Simple Method
Per Runoff Volume Simple Method NCDEQ Stormwater BMP Manual
PRE -DEVELOPMENT
RVPRE = 0.05 + 0.9 * IA
_ Existing Site Impervious Area
IA Total Area (Project Area)
_ 0
IA 158,994
1A = 0.00
RVPRE = 0.05
POST DEVELOPMENT
RvPosT = 0.05 + 0.9 * 1A
_ Developed Site Impervious Area (Prop. & Ex.)
IA Total Area (Project Area)
37,662
IA_ 158,994
1A = 0.24
RVPosT = 0.26 RvPosT = 0.12
(NO Gravel)
Newly created Impervious area for the Project =
37,662 SF

1.0" VOLUME REQUIRED For Project Area (LOD) Using Simple Method
Simple Method
V = 3630 * P * (RVPOST - RVPRE) * DA
P (1.0") = 1 IN
DA = 158,994 SF
DA = 3.65 AC
V = 3,487 CF = VOLUME REQUIRED FOR PROJECT AREA USING SIMPLE METHOD (DOES NOT FACTOR IN PRE -CONDITIONS IMP. AREA, REMOVES Rvpre FROM EQUATION)
V = 1,648 CF = VOLUME REQUIRED FOR PROJECT AREA USING SIMPLE METHOD (EXCLUDES GRAVEL)
STORMWATER VOLUME SUMMARY CALCULATIONS
VOLUME
@
TOP OF
TOP OF
INFILTRATION
SURFACE AREA @
DEPTH OF
PONDING
*VOL.
**INFILTRATIO
TOTAL
TOP OF
***BOTTOM
OVERFL
EMBANK
IMPERVIOUS
BASIN #
BOTTOM
PONDING
(TOP OF
VOIDS
N RATE
VOLUME
BASIN
OF BASIN
SHWT
OW
MENT
AREA
TREATING
OVERFLO
INLET
PONDING
W INLET)
(SF)
(FT)
(CF)
(CF)
(IN/HR)
(CF)
(FT)
(FT)
(FT)
(FT)
(FT)
(SF)
1
724
1.50
1,086
1,158
3.30
2,244
243.00
238.33
>236.33
244.50
244.50
11,282
2
1,391
0.33
459
2,226
2.02
2,685
223.77
219.10
>217.00
224.10
224.10
26,380
*Assumes a Void Ratio of 0.4 for the 1.5-2.5 inch speficied stone. Accounts for only the 4 feet of stone does not include pea gravel and sand.
** Based on observation from the geotechnical engineer
SHWT = Seasonal High Water Table
***The bottom of sand filter layer where in -situ infiltration rate occurs
Impervious Area Treating 37,662 sf
Newly created Impervious Area 37,662 sf
1.0" WQV Required, Project Area (LOD) (Simple Method, Pre -Development Conditions NOT Considered) 3,487 cf
1.0" WQV Required, Drainage Areas Only (Simple Method, Pre -Development Conditions NOT Considered) 3,357 cf
1.0" WQV Required, Drainage Areas Only (Simple Method, Pre -Development Conditions NOT Considered, NO Gravel) 1,648 cf
1.0" WQV Provided 4,929 cf

Ten Cwmcaner
uvuid used: Municipal water depth f water iaW: r m' water Temp ( l Pic ray °F
iest4OCirtiDn: 1-01 Qepth of Observed wirtar 26.4 inches
tkmnlmmtr
tEIpEIctty
Ljquzinqrr.
np
cm
Signs ruby
1L
sge 7 u .
k2n
Flow ratq ur."
Ios
Halm DianurW..
2A
iruheq
Stare SeLuratiornc
143D
Water Head:
7
inches
Hale Radirn' 1.MD Halt ID"mh_ 93 iryhm
Tate CUNA
�_
__

TUSt-CRrn}1Vnff
Uquid WkLu. t_4u1iG ft31 Water
Test Lean: 1-13d
Deptb & Wmer TaUe. �-96"
ovru t'¢rrts:
CapacHy
Liquid o Wei
MEWR
I r.Tkq FM r.n
SI�N[TI�Et
IL
1 31,
t�r+ge u t3 e
L
now ratewed:
Water Term i °Fk 65 9F
Depth of 06serred Water 44 inches
105 Hale [ ornetrr: 7-A inchim
5121PI Satliiatrifl: 15.0t} W64-W Head: 5 l hei
Hole RddFus- 1.20D Hale Depth: 5+6 inches
Est Varer
I
I
Om
m
m
Ml
®®®®
M
I
I
M
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ww"W"
IY--■■-■-_-
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mI==■■_■MM�
mI==■■_■MM�
mUJ==■■_■MM�
Stabilized

Channel Report
Hydraflow Express Extension for Autodesk0 AutoCADO Civil 3D0 by Autodesk, Inc.
Stormwater Infiltration #1 Overflow-Q10
Trapezoidal
Bottom Width (ft)
= 10.00
Side Slopes (z:1)
= 3.00, 3.00
Total Depth (ft)
= 0.50
Invert Elev (ft)
= 244.50
Slope (%)
= 1.85
N-Value
= 0.033
Calculations
Compute by:
Known Q
Known Q (cfs)
= 2.84
Elev (ft)
246.00
245.50
245.00
244.50
244.00
Section
D 2 4 6 8 10
Reach (ft)
Highlighted
Depth (ft)
Q (cfs)
Area (sqft)
Velocity (ft/s)
Wetted Perim (ft)
Crit Depth, Yc (ft)
Top Width (ft)
EGL (ft)
12 14
Wednesday, Jul 3 2019
= 0.16
= 2.840
= 1.68
= 1.69
= 11.01
= 0.14
= 10.96
= 0.20
Depth (ft)
1.50
1.00
0.50
ffixere,
-0.50
16 18
Page 23 of 29

Hydrograph Report
Hydraflow Hydrographs Extension for Autodesk® Civil 3D® 2019 by Autodesk, Inc. v2019.2
Friday, 06 / 28 / 2019
Hyd. No. 1
Channel 1
Hydrograph type
= Rational
Peak discharge
= 2.864 cfs
Storm frequency
= 10 yrs
Time to peak
= 5 min
Time interval
= 1 min
Hyd. volume
= 859 cuft
Drainage area
= 1.250 ac
Runoff coeff.
= 0.29*
Intensity
= 7.902 in/hr
Tc by User
= 5.00 min
OF Curve
= Pope_AAF_IDF_Hydrographs.J�e/Rec
limb fact
= 1/1
Composite (Area/C) = [(0.950 x 0.38) + (0.300 x 0.03)] / 1.250
Q (cfs)
3.00
rM
1.00
0.00
0 1
— Hyd No. 1
Channel 1
Hyd. No. 1 -- 10 Year
2 3 4 5 6 7 8 9
Q (cfs)
3.00
2.00
1.00
1 0.00
10
Time (min)
Page 24 of 29

Hydrograph Report
2
Hydraflow Hydrographs Extension for Autodesk® Civil 3D® 2019 by Autodesk, Inc. v2019.2
Hyd. No. 2
Channel 2
Hydrograph type
= Rational
Peak discharge
Storm frequency
= 10 yrs
Time to peak
Time interval
= 1 min
Hyd. volume
Drainage area
= 0.420 ac
Runoff coeff.
Intensity
= 7.902 in/hr
Tc by User
OF Curve
= Pope_AAF_IDF_Hydrographs.J�e/Rec
limb fact
Composite (Area/C) = [(0.137 x 0.95) + (0.283 x 0.30)] / 0.420
Q (cfs)
2.00
1.00
0.00
0 1
— Hyd No. 2
Channel 2
Hyd. No. 2 -- 10 Year
Friday, 06 / 28 / 2019
= 1.693 cfs
= 5 min
= 508 cuft
= 0.51 *
= 5.00 min
= 1/1
2 3 4 5 6 7 8 9
Q (cfs)
2.00
1.00
N 0.00
10
Time (min)
Page 25 of 29

Channel Report
Hydraflow Express Extension for Autodesk0 AutoCADO Civil 3D0 by Autodesk, Inc.
Channel 1 10 Yr Storm Rational Method
Triangular
Side Slopes (z:1)
= 12.00, 12.00
Total Depth (ft)
= 0.60
Invert Elev (ft)
= 244.50
Slope (%)
= 0.46
N-Value
= 0.040
Calculations
Compute by:
Known Q
Known Q (cfs)
= 2.86
Elev (ft) Section
246.00
245.50
245.00
244.50
244.00
Highlighted
Depth (ft)
Q (cfs)
Area (sqft)
Velocity (ft/s)
Wetted Perim (ft)
Crit Depth, Yc (ft)
Top Width (ft)
EGL (ft)
Wednesday, Jul 3 2019
= 0.50
= 2.860
= 3.00
= 0.95
= 12.04
= 0.33
= 12.00
= 0.51
2 4 6 8 10 12 14 16 18 20
Reach (ft) Page 26 of 29
Depth (ft)
1.50
1.00
0.50
ffixere,
_n tin

Channel Report
Hydraflow Express Extension for Autodesk0 AutoCADO Civil 3D0 by Autodesk, Inc.
Channel 2 10-Yr Storm Rational Method
Triangular
Side Slopes (z:1)
= 4.00, 4.00
Total Depth (ft)
= 0.50
Invert Elev (ft)
= 225.50
Slope (%)
= 4.84
N-Value
= 0.040
Calculations
Compute by:
Known Q
Known Q (cfs)
= 1.69
Elev (ft)
227.00
226.50
226.00
225.50
225.00
Section
Highlighted
Depth (ft)
Q (cfs)
Area (sqft)
Velocity (ft/s)
Wetted Perim (ft)
Crit Depth, Yc (ft)
Top Width (ft)
EGL (ft)
Friday, Jun 28 2019
= 0.40
= 1.690
= 0.64
= 2.64
= 3.30
= 0.41
= 3.20
= 0.51
.5 1 1.5 2 2.5 3 3.5 4 4.5
Reach (ft) Page 27 of 29
Depth (ft)
1.50
1.00
0.50
-0.50

LOD
LLOD
0 i� 41:9 — 242
243 .�
243 •� ,242'I_ �-� �,' \��� ( \ \\ \� �� �� �� I ��✓
141�7 1� �� V 13 V -A \ \ r
4 7 ��Vlo 15\�� �� �� +217.8'
••-244'_ \ "'141 V L- 10\
14
15"RCP -� 15 1
o CLASS IVS233.95 243.9 00� r� 1 1a\ �� 15 1
1s� �
10 1� ���o - —.• � s �� �� 1 \ A \ \
43y o �a �� is v A �1D� A \ \ \ \
\ \
233 -233 DIP 1z > 7 2q� �� 2
- 232.5 233.55 • 4 .2 '2 - � 1 0 1
12 1 235 243 _0�2� LL A
'247.0'�� 13
3 240 A•• �QD �� _ / i ��� _ ��LOD
�1• 45E�M �56 Y '� L(�D \D 2.
<p19
28'
246 246.5 ��� SOI ROD L�D
SWM#2 �2 7. 4 946.1 44.8 SD 1 Cp v-_ Z� v �� t—� D LOD
OFFSITE 6 _ • �.. � � ••
8" DIP 2l1$" \�
- P
• A� � D SD o SDI 15"RCSD SD 15"RC - CL SAS IV�-
• ) 244 243 24 241 2 0 w
�� �•�•• S I#1 y<244.75 246 245.5y� 245 L 8„DI �-�
•• Q +2 3 F6, �� 2455
OFF I����4 - _ �� 1 t
- E E LOD .
LOD 15
•!i�e246. 2455� 245.5 FFt = 233.00' 45. QS
E LOD DD SWp "# 245.5 SEE GRADING i oa 7
12 LOD 2 4.5 243.5 �� SHEET CG0102 8" DIPLOD * NOTE i 233
LOD 244.5 X
245 64 5 �244.5�
LOD A_ co i
® E E L 12 RC D'� 24
Ml�
C SS IV246.7
245.36 cE E 4 tia 2 A ZA • 245.7 i X244.25
243.�5 23J
tiN �3/ E 232.6� SD 15" RCP - CLSS IV a
Lai ®X243� 235 D 5D SD� SD Sp—�
244.8 240 E + 2 ® �• • �� f
44. 243 X43.5 �DD��
��� • X q3 E SOD J 7�a��
LOD • e _2 �> > > > • I ( �, f E\ — A
LOD • • / l E 1
LDOD LOD/ LOD f ��E
> J LOD �_ LOD LOD �� L06
3
LEGEND �STORMWATER MANAGEMENT DRAINAGE AREAS MANAGEMENT DRAINAGE AREAS
WM10 SCALE: V=30'
•• SWM DRAINAGE AREA-OFFSITE
o as sa
•• — SWM DRAINAGE AREA
SCALE IN FEET
NOT FOR CONSTRUCTION
I I
US Army Corps
of Engineers'
z
a
SHEET ID
SWM101

LOD ��LOD ti V \ j \
241 -7 LOD 101)
LOO 1. ti - 2427
\ ✓ �� 242, - - 243 00 FIF
1
ow
243' - - �- � � + � 1 � � \ � � � �� � � � l � �1 � � � � � � � � �\ \ IF,
-
�--2A� 1413
7 V \ 1D 15��
43' 7
N ��
•--•o �24 - _i� c�
4 10
C S_, 15„R � 114 1 15 1 s
Al DCLA SRIVS233.95 2A21 Cc) 14 � 10 15 1 1L!
-45-� 14 �� 1 10� ���
5 246�� 33 ��� DIP
4��lb \ 5 12 � 2 L �10 1
AO) 232.5 233.E1
_02� �
1 235
+247.0'\ 13 240
3 n
LOD
22.8'
245 a • A31 ��� L� Q <0, ,w19 -
246 zi ; 2� 5 244.8 \ "�� SOI RO D D L�D �\ - L D
F, 2 7. V 246. \ y Sa 75 RCptOn� LTB-
\5
C0� �� „ DI 43�85 15,R P5D SD 15 R SD 1�„RC� - CLAS IV� 1�
• x A A4 2 4 2 3 AS 2 1 2 0 sD o� V A7, A 1
/'+ 246 �.� �245
�245.50 8 „DI
�CHA #1 +2g3.3' v� 24.5
�• 1g�246.
E LOD 1,� �O 2 S 245.5 245.5 M': = 233\00' s L
E �� LOD LOD 15 lj �� 245.5 SEEO"GRADING_ i
LOD 0��• - '• - - - - - =1I- T 1V E=IN 2 3
ti f 244.5
LOD2�3.5
SHEC11 I2L2 6.
�244.5\
L x�.511 14E 2%l
�LO-
LOD
® E 12" RC
CLASS IV 67 I
BLDG5 245.36
E 2a
E •
01916 l0 • 24 . y . 245.7� X244.25
L� �• / C2,� 43. I 23 � J
232.G�B11 �SD i �D �15' R�P - CUSS �IV �D B2% a
n f 247.9 a 243 2 35 Sp
1-1
.6
o } 244.8 �240 �2? / +
�o 2
® ��� • ��
o -� S W M# 1 \ 44.50 243 9 • • �p0
o - J%
F,
STORM DRAIN AND CHANNEL DRAINAGE AREAS � �% �� i �l E yP0 l 7
WM10 SCALE: V" 30' V '0 QO •��� E �
o sa ea LOD �� LOD �� ��• • i • > p0/11 L �
SCALE IN FELT �� D �� D OD LOD LOD
_ LOD LOD L10 J
LEGEND
•• CHANNEL DRAINAGE AREA
- - - - - - STORM DRAIN DRAINAGE AREA
n=
0.013
STORM DRAINAGE SCHEDULE
CONTINUED -
STORM DRAINAGE SCHEDULE -CONTINUED
g=
208
h=
21
1=
7.92
INLET
INLET
INLET
Cc
INLET
TOTAL
INLET
PIPE
TIC
TIME
I
Cc
RUNOFF
Q
Q
SIDE-
CAPACITY
SEGMENT
UPPER
LOWER
UPSTREAM
TOP
PIPE
FROM
TO
AREA
AREA
IMPERVIOUS
RUNOFF
DISCHARGE
AREAS
TIME
TIME
OF CONC.
INTENSITY
COEFF.
DISCHARGE
STREAM
SLOPE
DIA.
(FULL)
V FULL
LENGTH
TIME
INV.
INV.
ELEV.
COVER
(SF)
(AC)
(%)
COEFF.
(CFS)
(AC)
(MIN)
(MIN)
(MIN)
(INlHR)
(CFS)
(CFS)
(IN)
(CFS)
(FPS)
(FT)
(MIN)
(FT)
(FT)
(FT)
(FT)
AO
Al
7,324
0.17
25
0.46
0.61
0.17
5.00
0.00
5.00
7,92
0.46
0.61
0.00
0.0054
15
4.8
3.9
48
0.21
227.56
227.60
232.05
2.63
Al
A2
19.054
0.44
27
0.47
1.64
0.44
5.00
0.00
5.00
7.92
0.47
1.64
0.00
0.0054
15
4.7
3.8
112
0.49
227.50
226.90
231.80
2.94
A2
A3
2,296
0.05
45
0.59
0.25
0,49
5.00
0.49
5.49
778
0,49
1.85
0.00
0.0037
15
3.9
3.2
68
0.36
226.80
226.55
243.90
15.74
A3
A4
2,374
0.05
39
0.66
0.24
0.54
5.00
0.84
5.84
767
0.49
2.06
0.00
0.0041
15
4.1
3.4
86
0.43
226.46
226.10
244.80
16.99
A4
A5
2,650
0.07
21
OA3
0.22
0.61
5.00
127
6.27
7.55
0.49
2.24
0.00
0.0052
15
4.7
3.8
77
0.34
226A0
225.70
243.80
16.34
AS
A6
0
0.00
0.30
0.00
0.61
5.00
1.61
6.61
7.46
0.49
2.22
0.00
0.0044
15
4.3
3.5
91
0.44
225.60
225.20
241.70
14.74
A6
A7
0
0.00
0.30
0.00
0.61
5.00
2.04
7.04
7.35
0.49
2.18
0.00
0.0049
15
4.5
3.7
102
0,46
225.10
224.60
236.00
9.54
B1
B2
13,963
0.32
10
0.37
0.93
0.32
5.00
0.00
5.00
7.92
0.37
0.93
0.00
0.0056
15
4.8
3.9
270
1.15
227.50
226.00
232.65
3.79
C1
C2
27,655
0.63
41
0.57
2.84
0.63
5.00
0.00
5.00
7.92
0.57
2.84
0.00
0.0100
12
3.6
4.5
50
0.18
243.50
243.00
246.50
1.91
NOT FOR CONSTRUCTION
I I
US Army Corps
of Engineers'
z
a
SHEET ID
SWM 102