SW3170801_HISTORICAL FILE_20171207

STORMWATER DIVISION CODING SHEET
POST -CONSTRUCTION PERMITS
PERMIT NO.
SW-
DOC TYPE
❑ CURRENT PERMIT
❑ APPROVED PLANS
HISTORICAL FILE
❑ COMPLIANCE EVALUATION INSPECTION
DOC DATE
YYYYMMDD

Transmittal Letter
Date: September 8, 2017
To: Mr. Rick Riddle
NC Dept of Environmental Quality
DEMLR Stormwater Program
512 N. Salisbury St.
Raleigh, NC 27699-1612
919-807-6369
Project: DaVita — Spencer
Rowan County, NC
We Transmit:
(X) herewith
() under separate cover
to
Project #: 17-025/D
AeW/o bon
c�1/4e
M
svp 1 it , 2017
For Your:
Q approval
Q review and comment
(X) signatures
Copies_
Date
Description
O&M EZ form
1
EZ Form
Comments:
Please find attached a signed permit application along with two sets of construction plans for
review and approval. Please contact me if you have any questions. Thank you.
Copies: File
Submitted by: Matthew W. Johnson, P.E.
Civil Engineer
4807 - C Koger Boulevard, Greensboro, NC 27407 1 T - 336-218-8282 F - 336-218-8010 1 www.triad-designgroup.com

rol

� r
I
Erosion Control and
Stormwater Report
RECEIVED
AUG 01 2017
DENR-LAND QUALITY
STORMWATER PERMITTING
RECEIVE®
DEC 7 2017 DaVita Spencer
OENR
-0EMLR
Mo Land Quality Section esville Regional Once
Project Location: Spencer, North Carolina Project #: 17-025
Designer:
Triad Design Group, P.C.
4807-C Koger Blvd
Greensboro, NC 27407
July 27, 2017
triaddesigngroup
ARCHITECTURES ENGINEERING I INTERIOR DESIGN
4807 - C Koger Boulevard, Greensboro, NC 27407 1 T - 336-218-8282 F - 336-218-8010 I www.triad-designgroup.com

k,l �

Stomwater Report
DaVita Spencer
Rowan County North Carolina
17-025
Narrative:
The purpose of this project is to construct a 9,121 sf building with associated drive and parking aisles on
the 4.951 acre site located at the physical address of 1287 Salisbury Avenue. The existing site currently
has approximately 0.13 acres of BUA. An additional 0.94 acres of BUA are being proposed due to the
proposed construction, with an area for a 0.07 acres building addition bringing the total BUA to 1.14
acres or 23.02% BUA. A wet detention pond will be constructed to treat hand detain the increased flow
created by the additional BUA created due to the project. The 1, 2, and 10 year storm events have been
modeled and the runoff from wet detention pond has been reduced to pre -development rates. A
summary of the flows are listed below.
Drainage Area 1-
Pre-Development
DA-1
Post -Development
DA-1
Drainage Area
1.67 AC
2.23 AC
CN
64
82
BUA
0.13 Acres
1.14 Acres
Tc
10 min
5 min
Flows —
Flows
Pre -Development
Condition DA-1
Post -Development
Condition DA-1
Routed Condition
DA-1
1-yr 24-hr
0.587 cfs
4.453 cfs
0.016cfs
2 yr 24-hr
1.229 cfs
6.115 cfs
0.146 cfs
10 yr 24-hr
3.380 cfs
10.81 cfs
3.005 cfs
100 yr 24-hr
7.435 cfs
18.30 cfs
8.961 cfs
11Page

rOND CHECK Future- RISER2.gpw
07/28/17
PERMANENT
WET DETENTION POND DESIGN - RISER/BARREL
Revised 8-24-99
GUILFORD COUNTY
PLANNING & DEVELOPMENT DEPARTMENT
DaVita bpencer INDEX NO: INDEX
CHECKED BY: MWJ
LOCATION:
Spencer INC DATE: April 06, 2017
REVISED:
SITE DATA
TOTAL SITE AREA = 4.99 WATERSHED = RANDLEMAN DAM
Existing
_
BUILT UPON AREA = 0.13 CLASSIFICATION: WS - IV
Proposed
BUILT UPON AREA = 1.01 (GWAIWCA) _ GWA
TOTAL ON -SITE
_
BUILT UPON AREA = 1.14
PERCENT BUILT -UPON = 22.85%
ON -SITE DRAINAGE AREA TO POND = 2.23
ON -SITE BUA TO POND = 1.14
NSITE % BUA FOR POND SUB -BASIN = 51.12%
OFF -SITE DRAINAGE AREA TO POND = 0.36 MAX. OFF -SITE B.U.% = 70%
TOTAL WATERSHED AREA TO POND = 2.59
DISTURBED AREA = 2.50
TEMP. SED. STOR. USED /N
DESIGN DATA
TEMPORARY SEDIMENT STORAGE 0.5 acre -inch per disturbed acre
PERMANENT SEDIMENT STORAGE 0.125 _acre -in per total drainage area
PERMANENT WATER QUALITY
COMPOSITE B.U. % _ _ 53.75 _ percent
DEPTH (minimum 3 feet) 3.4 feet
SA/DA .(Figure 5.6-2) _ 3.26 percent
TEMPORARY WATER QUALITY 1.0 rainfall to be controlled
PRINCIPAL SPILLWAY
TYPE X _corrugated aluminum
reinforced concrete
DESIGN STORM 10 year
RAINFALL INTENSITY 6.89 inches per hour
RUNOFF COEFFICIENT 0.63
EMERGENCY SPILLWAY
TYPE X grass lined
rip -rap lined
DESIGN STORM 100 year
RAINFALL INTENSITY _ 8 inches per hour
RUNOFF COEFFICIENT 0.8
POND DATA
ELEV. @ BOT. OF POND = 730.5 SURFACE AREA = 829
ELEV.@ BOT. OF PSS = 730.5 SURFACE AREA = 829
ELEV. @ BOT. OF PWQ = 732 SURFACE AREA = 1364
ELEV.
@ NORMAL POOL = 736.5 SURFACE AREA = 5660
ELEV.
@ TOP. OF RISER = 737.75 SURFACE AREA = 7978
ELEV.
@ EMER. SPILLWAY = 738.5
ELEV_ @ TOP OF DAM = 740
INVERT OF BARREL = 728
POND DESIGN
TEMPORARY SEDIMENT STORAGE VOLUME REQUIRED 4538
Page 1

POND CHECK Future- RISER2.gpw
07/28/17
VOLUME PROVIDED
LEV. @ BOT. OF POND= 730.50
LEV. @ NORMAL POOL = 736.50
SURFACE AREA = _829
SURFACE AREA = 5660
ALLOW 75% OF BASIN VOLUME TO WQ ORIFICE =
14600
OK
PERMANENT SEDIMENT STORAGE VOLUME REQUIRED
VOLUME PROVIDED
ELEV. @ BOT. OF PSS = 730.50 SURFACE AREA = 829
ELEV. @ BOT. OF PWQ = _732.00 SURFACE AREA = _ 1364
VOLUME PROVIDED =
1175
1645
OK
PERMANENT WATER QUALITY SURFACE AREA REWD
3678
NORMAL POOL ELEVATION =
SURFACE AREA PROVIDED =
736.50
5660
OK
TEMPORARY WATER QUALITY STORAGE REQUIRED
Rv=
0.534
VOLUME REQUIRED =
5018
VOLUME PROVIDED
ELEV. @ BOT. OF TWO = _736.50
ELEV. @ TOP OF TWO = 737.75
SURFACE AREA = 5660
SURFACE AREA = _7978
VOLUME PROVIDED = _
8524
OK
Page 2

A
64
DaVita Spencer
Average Pond Depth NC DEQ Stormwater
Manual Figure 10-2b
Depth
1
lent pool voulme divided by permanent pool surface area
Volume Pv = 167322
n Pool Surface Aree PSA = 49924.08
Depth davg = 3.351529
E
bottom shelf
Abs =
4148
perm pool
App =
5660
bottom pond
Abp =
1366
:pth
D =
4.5
davg = 3.424175
Hydro Flow
Pond Check Sheet
4807-C Koger Blvd
Greensboro, NC 27407
336-218-8282 ` 336-218-8010 Fax

`,
Water Quality Draw Down Time
Size of Hole 1 0.75 1 0.003068
Storage Volume 6919
Surface Area of Pond ftA2 (As) 28067
Head of Water above Hole, ft (h) 2
Coefficient of Contraction of an orrifice (0.6) 0.6
Time to Dewater Days 3.83328
Q= 0.02089 cfs
Qmin 0.01602 5 days
Qmax 0.04004 2 days

,Watershed Model Schematic Hydraflow Hydrographs Extension for AutoCADO Civil 3DO2016 by Autodesk, Inc. v11
1
2
Legend
Hrd- Origin Description
1 SCS Runoff Pre Development
2 SCS Runoff Post Development
3 Reservoir Proposed Pond
Project: Pond Routing.gpw
Wednesday, 06 / 7 / 2017

2
, Hydrograph Return Period RegM
y ow Hydrogrophs Extension for AutoCADrRJ Civil 3D® 2016 by Autodesk, Inc. v11
Hyd.
Hydrograph
Inflow
Peak Outflow (cfs)
Hydrograph
No.
type
hyd(s)
Description
(origin)
1-yr
2-yr
3-yr
5-yr
10-yr
25-yr
50-yr
100-yr
1
SCS Runoff
0.587
1.229
3.380
7.435
Pro Development
2
SCS Runoff
4.453
6.115
10A1
18.30
Post Development
3
Reservoir
2
0.015
0.096
1.681
8.035
Proposed Pond
Proj. file: Pond Routing.gpw
Wednesday, 06 / 7 / 2017

3
,Hydrograph Summary Report Hydmflow Hydrographs Extension for AutoCAD® Civil MEN) 2016 by Autodesk, Inc. vl1
Hyd.
No.
Hydrograph
type
(origin)
Peak
flow
(cfs)
Time
interval
(min)
Time to
Peak
(min)
Hyd.
volume
(curt)
Inflow
hyd(s)
Maximum
elevation
(fl)
Total
strge used
(cufl)
Hydrograph
Description
1
SCS Runoff
0.587
2
724
2,251
Pre Development
2
SCS Runoff
4.453
2
718
8,937
Post Development
3
Reservoir
0.015
2
1444
3,914
2
737.53
21,375
Proposed Pond
Pond Routing.gpw
Return Period: 1 Year
Wednesday, 06 / 7 / 2017

Hydrograph Report 4
Hydmflow Hydmgmphs Extension for AutoCAD® Civil 3D® 2016 by Autodesk, Inc. v11
Hyd. No. 1
Pre Development
Hydrograph type
= SCS Runoff
Storm frequency
= 1 yrs
Time interval
= 2 min
Drainage area
= 1.670 ac
Basin Slope
= 0.0 %
Tc method
= User
Total precip.
= 2.74 in
Storm duration
= 24 hrs
Wednesday, 061712017
Peak discharge
= 0.587 cfs
Time to peak
= 12.07 hrs
Hyd. volume
= 2,251 cuft
Curve number
= 64*
Hydraulic length
= 0 ft
Time of conc. (Tc)
= 10.00 min
Distribution
= Type II
Shape factor
= 484
' Composite (Ama/CN) = [(0.130 x 98) + (1.540 x 61)] 11.670
Pre Development
Q (cfs) Q (cfs)
Hyd. No.1 —1 Year
1.00
0.so
0.80- .
0.70
0.60
0.50
0.40
0.30
0.20
0.10
0.00
0 2 4
Hyd No. 1
MIN , ,
IMENIZEEMEME
t__ itttttt��t_tt_tt_tt_tt_tt_
,,1
t r

Hydrograph Report
5
Hydraflow Hydrographs Extension for Aul oCAD® Civil 3D® 2016 by Autodesk, Inc. v11
Hyd. No. 2
Post Development
Hydrograph type
= SCS Runoff
Storm frequency
= 1 yrs
Time interval
= 2 min
Drainage area
= 2.230 ac
Basin Slope
= 0.0 %
Tc method
= User
Total precip.
= 2.74 in
Storm duration
= 24 hrs
Wednesday, 06 / 7 / 2017
Peak discharge
= 4.453 cfs
Time to peak
= 11.97 hrs
Hyd. volume
= 8,937 cuft
Curve number
= 82*
Hydraulic length
= 0 ft
Time of conc. (Tc)
= 5.00 min
Distribution
= Type II
Shape factor
= 484
Composite (Area/CN) _ [(0.800 x 61) + (1.070 x 98) + (0.360 x 78)) / 2.230
Post Development
Q (cfs) Hyd. No. 2 — 1 Year Q (Cfs)
5.00 5.00
4.00 4.00
3.00 3.00
2.00 2.00
1.00 1.00
0.00 0.00
0 2 4 6 8 10 12 14 16 18 20 22 24 26
Hyd No. 2 Time (hrs)

Hydrograph Report 6
Hydraflow Hydrographs Extension for AutoCAD® Civil 3D® 2016 by Autodesk, Inc. v1 t
Hyd. No. 3
Proposed Pond
Hydrograph type = Reservoir
Storm frequency = 1 yrs
Time interval = 2 min
Inflow hyd. No. = 2 -Post Development
Reservoir name = Proposed Pond
Storage Indication method used. Wet pond routing start elevation = 736.25 ft.
Wednesday, 06 / 7 / 2017
Peak discharge
= 0.015 cfs
Time to peak
= 24.07 hrs
Hyd. volume
= 3,914 cuft
Max. Elevation
= 737.53 ft
Max. Storage
= 21,376 cuft
Proposed Pond
Q (cfs)
Hyd. No. 3 -- 1 Year
5.00
4.00
3.00
M
1.00
I
Q (ofs)
5.00
2.00
1.00
0 10 20 30 40 50 60 70 80 90 100
Time (hrs)
— Hyd No. 3 —Hyd No. 2 1 Total storage used = 21,376 tuft

.Hydrograph Summary Report Hydraflow Hydrogrophs Extension for AutoCAD® Civil 3D®2016 by Autodesk, Inc. v11
Hyd.
No.
Hydrograph
type
(origin)
Peak
flow
(cfs)
Time
interval
(min)
Time to
Peak
(min)
Hyd.
volume
(cuff)
Inflow
hyd(s)
Maximum
elevation
(fl)
Total
strge used
(cufl)
Hydrograph
Description
1
SCS Runoff
1.229
2
722
3,821
Pro Development
2
SCS Runoff
6.115
2
716
12,347
Post Development
3
Reservoir
0.096
2
1098
5,946
2
737.76
23,270
Proposed Pond
Pond Routing.gpw
Return Period: 2 Year
Wednesday, 06 / 7 / 2017

Hydrograph Report
8
Hydrafimv Hydrogmphs Extension for AutoCAD® Civil 31382016 by Autodesk, Inc. v11
Hyd. No. 1
Pre Development
Hydrograph type
= SCS Runoff
Storm frequency
= 2 yrs
Time interval
= 2 min
Drainage area
= 1.670 ac
Basin Slope
= 0.0 %
Tc method
= User
Total precip.
= 3.31 in
Storm duration
= 24 hrs
Composite (AreaICN) = [(0.130 x 98) + (1.540 x 61)] 11.670
Q (cfs)
2.00
1.00
CTTa�
Wednesday, D6 I712017
Peak discharge
= 1.229 cfs
Time to peak
= 12.03 hrs
Hyd. volume
= 3,821 cuft
Curve number
= 64*
Hydraulic length
= 0 ft
Time of conc. (Tc)
= 10.00 min
Distribution
= Type II
Shape factor
= 484
Pre Development
Hyd. No.1 — 2 Year
Q (cfs)
2.00
MVw
0 2 4 6 8 10 12 14 16 18 20 22 24 26
— Hyd No. 1 Time (hrs)

9
Hydrograph
Report
Hydraflow Hydregraphs Extension for AutoCAD® Civil 3DOD2016 by Autodesk, Inc. v11
Wednesday, 06 / 7l 2017
Hyd. No. 2
Post Development
Hydrograph type
= SCS Runoff
Peak discharge
= 6.115 cfs
Storm frequency
= 2 yrs
Time to peak
= 11.93 hrs
Time interval
= 2 min
Hyd. volume
= 12,347 cuft
Drainage area
= 2.230 ac
Curve number
= 82"
Basin Slope
= 0.0 %
Hydraulic length
= 0 ft
Tc method
= User
Time of conc. (Tc)
= 5.00 min
Total precip.
= 3.31 in
Distribution
= Type II
Storm duration
= 24 hrs
Shape factor
= 484
Composite (Area/CN) = ](0.800 x 61) + (1.070 x 98) + (0.360 x 78)] / 2.230
'r 1 •r
11 -----_OEM IN1'1
0 2 4 6 8 10 12 14 16 18 20 22 24 26
Hyd No 2 Time (hrs)

10
Hydrograph
Report
Hydra6ow Hydrographs Extension for AutoCAD® Civil 3D® 2016 by Autodesk, Inc. v11
Wednesday, 06I 7I 2017
Hyd. No. 3
Proposed Pond
Hydrograph type
= Reservoir
Peak discharge
= 0.096 cfs
Storm frequency
= 2 yrs
Time to peak
= 18.30 hrs
Time interval
= 2 min
Hyd. volume
= 5,946 cuft
Inflow hyd. No.
= 2 -Post Development
Max. Elevation
= 737.76 ft
Reservoir name
= Proposed Pond
Max. Storage
= 23,270 cuft
Storage Indication method used. Wet pond routing start elevation = 736.25 ft.
Proposed Pond
Q (cfs) Hyd. No. 3 -- 2 Year Q (Cfs)
7.00 7.00
6.00 6.00
5.00 5.00
4.00 4.00
3.00 3.00
2.00 2.00
1.00 1.00
0 00 000
0 10 20 30 40 50 60 70 80 90 100
Time (hrs)
— Hyd No. 3 —Hyd No. 2 — i Total storage used = 23,270 cult

11
Hydrograph Summary Report Hydraflow Hydrographs Extension for AutoCAD® Civil 3DO2016 by Autodesk, Inc. v11
Hyd.
No.
Hydrograph
type
(origin)
Peak
flow
(cry)
Time
interval
(min)
Time to
Peak
(min)
Hyd.
volume
(cult)
Inflow
hyd(s)
Maximum
elevation
(ft)
Total
strge used
(cuft)
Hydrograph
Description
1
SCS Runoff
3.380
2
722
9,118
Pm Development
2
SCS Runoff
10.81
2
716
22,082
Post Development
3
Reservoir
1.681
2
726
15.673
2
737.91
24.429
Pmposed Pond
Pond Routing.gpw
Return Period: 10 Year
Wednesday, 06 / 7 / 2017

12
Hydrograph Report
Hydmflow Hydrographs Extension for AuWAD® Civil 3138 2016 by Aulodesk, Inc. v11
Wednesday, 06 / 712017
Hyd. No. 1
Pre Development
Hydrograph type
= SCS Runoff
Peak discharge
= 3.380 cfs
Storm frequency
= 10 yrs
Time to peak
= 12.03 hrs
Time interval
= 2 min
Hyd. volume
= 9,118 cult
Drainage area
= 1.670 ac
Curve number
= 64'
Basin Slope
= 0.0 %
Hydraulic length
= Oft
Tc method
= User
Time of conc. (Tc)
= 10.00 min
Total precip.
= 4.81 in
Distribution
= Type II
Storm duration
= 24 hrs
Shape factor
= 484
Composite (Area/CN)=1(0.130 x 98) + (1.540 x 61)] 11.670
Q (cfs)
4.00
KM
1.00
0.00 '
0 2 4
Hyd No. 1
6 8
Pre Development
Hyd. No. 1 —10 Year
Q (cfs)
4.00
3.00
r't
1.00
' 'r ' ' ' ' I ' 0.00
10 12 14 16 18 20 22 24 26
Time (hrs)

Hydrograph Report
13
Hydraflm Hydrographs Fxdension for AutoCAD® Civil 3DOD2016 by Autodesk, Inc. v11
Wednesday, 06 / 7 / 2017
Hyd. No. 2
Post Development
Hydrograph type
= SCS Runoff
Peak discharge
= 10.81 cfs
Storm frequency
= 10 yrs
Time to peak
= 11.93 hrs
Time interval
= 2 min
Hyd. volume
= 22,082 cuft
Drainage area
= 2.230 ac
Curve number
= 82*
Basin Slope
= 0.0 %
Hydraulic length
= 0 ft
Tc method
= User
Time of conc. (Tc)
= 5.00 min
Total precip.
= 4.81 in
Distribution
= Type II
Storm duration
= 24 hrs
Shape factor
= 484
Composite (Area/CN) = [(0.800 x 61) + (1.070 x 98) + (0.360 x 78)) / 2.230
Q (cfs)
12.00
t tt
c rt
4.00
2.00
0.00
0.0 2.0
Hyd No. 2
Post Development
Hyd. No. 2 — 10 Year
4.0 6.0 8.0 10.0 12.0
Q (cfs)
12.00
10.00
Mr
MIN
4.00
2.00
' 0.00
14.0 16.0 18.0 20.0 22.0
Time (hrs)

Hydrograph Report
14
Hydra6ow Hydrographs Extension for AutoCAD® Civil 3D® 2016 by Autodesk, Inc. v11
Hyd. No. 3
Proposed Pond
Hydrograph type = Reservoir
Storm frequency = 10 yrs
Time interval = 2 min
Inflow hyd. No. = 2 -Post Development
Reservoir name = Proposed Pond
Storage Indication method used. Wet pond routing start elevation = 736.25 ft
Peak discharge
Time to peak
Hyd. volume
Max. Elevation
Max. Storage
Wednesday. 06/7/2017
= 1.681 cfs
= 12.10 hrs
= 15,673 cuft
= 737.91 ft
= 24,429 cult
Proposed Pond
Q (cfs) Hyd. No. 3 -- 10 Year Q (s)
12.00 12.00
10.00 10.00
8.00 8.00
6.00 6.00
4.00 4.00
2.00 2.00
0.00 0.00
0 2 4 6 8 10 12 14 16 18 20 22 24 26
Time (hrs)
— Hyd No. 3 —Hyd No. 2 _J Total storage used = 24,429 tuft

15
Hydrograph Summary Report Hydraflow Hydrographs Extension for AutoCAD® Civil 31382016 by Autodesk. Inc. vtt
Hyd.
No.
Hydrograph
type
(origin)
Peak
flow
(cfs)
Time
interval
(min)
Time to
Peak
(min)
Hyd.
volume
(cuft)
Inflow
hyd(s)
Maximum
elevation
(ft)
Total
strge used
(cuft)
Hydrograph
Description
1
SCS Runoff
7.435
2
720
19,431
Pre Development
2
SCS Runoff
18.30
2
716
38,305
Post Development
3
Reservoir
8.035
2
722
31,889
2
738.51
29,571
Proposed Pond
Pond Routing.gpw
Return Period: 100 Year
Wednesday, 06 / 7 / 2017

16
Hydrograph
Report
Hydraflow Hydrographs Extension for AutoCAD® Civil 3D®2016 by Autodesk, Inc. v11
Wednesday, 06 / 7l 2017
Hyd. No. 1
Pre Development
Hydrograph type
= SCS Runoff
Peak discharge
= 7.435 cfs
Storm frequency
= 100 yrs
Time to peak
= 12.00 hrs
Time interval
= 2 min
Hyd. volume
= 19,431 cult
Drainage area
= 1.670 ac
Curve number
= 64*
Basin Slope
= 0.0 %
Hydraulic length
= Oft
Tc method
= User
Time of conc. (Tc)
= 10.00 min
Total precip.
= 7.14 in
Distribution
= Type II
Storm duration
= 24 hrs
Shape factor
= 484
Composite (Area/CN) = ((0.130 x 98) + (1.540 x 61)) / 1.670
Q (cfs)
8.00
6.00
m
41111
0.00
0 2 4
Hyd No. 1
Pre Development
Hyd. No. 1 —100 Year
Q (cfs)
B.00
4.00
2.00
' T'*1 0.00
6 8 10 12 14 16 18 20 22 24 26
Time (hrs)

,Hydrograph Report
17
Hydraflow Hydrographs Extension for AutoCAD® Civil 3D® 2016 by Aulodesk. Inc. v11
Hyd. No. 2
Post Development
Hydrograph type
= SCS Runoff
Storm frequency
= 100 yrs
Time interval
= 2 min
Drainage area
= 2.230 ac
Basin Slope
= 0.0 %
Tc method
= User
Total precip.
= 7.14 in
Storm duration
= 24 hrs
Composite (Area/CN) = [(0.800 x 61) + (1.070 x 98) + (0.360 x 78)] 12.230
Q (cfs)
21.00
18.00
Peak discharge
Time to peak
Hyd. volume
Curve number
Hydraulic length
Time of conc. (Tc)
Distribution
Shape factor
Post Development
Hyd. No. 2 —100 Year
Wednesday, 06 / 7 / 2017
= 18.30 cfs
= 11.93 hrs
= 38,305 cult
= 82*
= 0 ft
= 5.00 min
= Type II
= 484
Q (cfs)
21.00
18.00
Ii rT1
12.00
"IN,
. tt
3.00
0.00
18.0 20.0 22.0
Time (hrs)

18
Frydrograph Report
Hydraflow Hydrographs Extension for AutoCAD® Civil 3D® 2016 by Autodesk, Inc. v11
Hyd. No. 3
Proposed Pond
Hydrograph type
= Reservoir
Storm frequency
= 100 yrs
Time interval
= 2 min
Inflow hyd. No.
= 2 -Post Development
Reservoir name
= Proposed Pond
Storage Indication method used. Wet pond routing start elevation = 736.25It
Wednesday, 061712017
Peak discharge
= 8.035 cfs
Time to peak
= 12.03 hrs
Hyd. volume
= 31,889 cuft
Max. Elevation
= 738.51 ft
Max. Storage
= 29,571 cuft
Proposed Pond
Q (Cfs) Hyd. No. 3 -- 100 Year Q (cfs)
21.00 21.00
18.00 18.00
15.00 15.00
12.00 12.00
9.00 9.00
6.00 6.00
3.00 3.00
0000 00
0 2 4 6 8 10 12 14 16 18 20 22 24 26
Time (hrs)
— Hyd No. 3 —Hyd No. 2 — ___ 1 Total storage used = 29,571 cult

19
Hydraflow Rainfall Report
Hydmnow Hydmgmphs Extension for AutoCAD® Civil 3D®2016 by Autodesk, Inc. v11 Wednesday, 06 / 7 / 2017
Return
Period
Intensity-0uration-Frequency Equation Coefficients (FHA)
(Yrs)
B
0
E
(NIA)
1
62.3444
12.9000
0.8970
-
2
69.3303
12.8000
0.8761
3
0.0000
0.0000
0.0000
-
5
70.1736
12.6000
0.8315
-
10
72.6290
12.7000
0.8116
-
25
60.3885
11.1000
0.7422
-
50
47.4392
9.2000
0.6687
-
100
47.9028
9.2000
0.6571
-
File name: Rainfall Curve -Alamance Foods 15-083.IDF
Intensity = B I (Tc + D)AE
Ratum
Period
Intensity Values (in/hr)
(Yrs)
5 min
10
15
20
25
30
35
40
45
50
55
60
1
4.69
3.76
3.15
2.72
2.39
2.14
1.94
1.77
1.64
1.52
1.42
1.33
2
5.56
4.48
3.77
3.26
2.88
2.58
2.34
2.15
1.98
1.84
1.72
1.62
3
OM
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
5
6.46
5.25
4.45
3.87
3.44
3.10
2.83
2.60
2.41
2.25
2.11
1.99
10
7.05
5.76
4.90
4.28
3.82
3.45
3.15
2.91
2.70
2.53
2.37
2.24
25
T68
6.28
5.36
4.71
4.22
3.83
3.52
3.26
3.04
2.85
2.69
2.55
50
8.05
6.58
5.63
4.97
4.47
4.08
3.77
3.50
3.29
3.10
2.93
2.79
100
8.38
6.87
5.90
5.22
4.70
4.30
3.97
3.70
3.48
3.28
3.11
2.96
Tc = time in minutes. Values may exceed 60.
Preci . file name: Sample.pc
storm
Rainfall Precipitation Table (in)
Distribution
1-yr
2-yr
3-yr
5-yr
10-yr
25-yr
50-yr
100-yr
SCS 24-hour
2.74
3.31
0.00
3.30
4.81
5.81
6.80
7.14
SCS 6-Hr
0.00
1.80
0.00
0.00
2.60
0.00
0.00
4.00
Huff -1st
0.00
1.55
0.00
2.75
4.00
5.38
6.50
8.00
Huff-2nd
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
Huff-3rd
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
Huff-4lh
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
Huff-Indy
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
Custom
0.00
1.75
0.00
2.80
3.90
5.25
6.00
7.10

,ydraflow Table of Contents
N
Pond Routing.gpw
Hydraflow Hydrographs Extension for AutoCAD® Civil 3D® 2016 by Autodesk, Inc. v11 Wednesday, 06 / 7 / 2017
Watershed Model Schematic..................................................................................... 1
Hydrograph Return Period Recap............................................................................. 2
1 - Year
SummaryReport......................................................................................................................... 3
HydrographReports................................................................................................................... 4
Hydrograph No. 1, SCS Runoff, Pre Development.................................................................. 4
Hydrograph No. 2, SCS Runoff, Post Development................................................................. 5
Hydrograph No. 3, Reservoir, Proposed Pond... ...................................................................... 6
2 - Year
SummaryReport ......................................................................................................................... 7
HydrographReports................................................................................................................... 8
Hydrograph No. 1, SCS Runoff, Pre Development.................................................................. 8
Hydrograph No. 2, SCS Runoff, Post Development................................................................. 9
Hydrograph No. 3, Reservoir, Proposed Pond....................................................................... 10
10 - Year
SummaryReport ....................................................................................................................... 11
HydrographReports................................................................................................................. 12
Hydrograph No. 1, SCS Runoff, Pre Development................................................................ 12
Hydrograph No. 2, SCS Runoff, Post Development............................................................... 13
Hydrograph No. 3, Reservoir, Proposed Pond....................................................................... 14
100 - Year
SummaryReport ....................................................................................................................... 15
HydrographReports................................................................................................................. 16
Hydrograph No. 1, SCS Runoff, Pre Development................................................................ 16
Hydrograph No. 2, SCS Runoff, Post Development............................................................... 17
Hydrograph No. 3, Reservoir, Proposed Pond....................................................................... 18
IDFReport .................................................................................................................. 19