Poplin Meadows - Poplin Meadows -Stormwater Report - 180605

BOHLER ENGINEERING 1927 S TRYON ST. ♦ SUITE 310 ♦ CHARLOTTE, NC 28203 ♦ 980.272.3400

STORMWATER MANAGEMENT REPORT
PREPARED FOR:

THE MOSER GROUP
BONTERRA VILLAGE WAY
INDIAN TRAIL, NC
UNION COUNTY
BEPC #NCC172107

June 5, 2018

PREPARED BY:
BOHLER ENGINEERING, NC, PLLC
1927 S. TYRON ST. SUITE 310
CHARLOTTE, NC 28203
[phone]

__ ________________________________
NORTH CAROLINA LICENSE #043610
MICHAEL THEBERGE, P.E.

PROFESSIONAL CERTIFICATION: I HEREBY CERTIFY THAT THESE DOCUMENTS WERE PREPARED OR APPROVED BY ME, AND
THAT I AM A DULY LICENSED REGISTERED ENGINEER UNDER THE LAWS OF THE STATE OF NORTH CAROLINA

CIVIL & CONSULTING ENGINEERS▪SURVEYORS▪TRAFFIC CONSULTANTS
www.bohlereng.com

2

Table of Contents

General Project Description ................................................................................................................. 3

Stormwater Management Analysis and BMP Calculations .................................................................. 4

Appendix ............................................................................................................................................... 6
HydroCAD Output ..........................................................................................................................
Stormsewer Output .......................................................................................................................

3

General Project Description/Stormwater Management

GENERAL PROJECT OVERVIEW AND EXISTING CONDITIONS

The subject site is located along Bonterra Village Way, in Union County. The project site is
currently vacant and consists of approximately 11.48 acres and will include approximately 99
single family lots. There is an existing intermittent stream following the southwest side of the
property line

The site is majority pasture with some wooded areas, with average existing slopes of 3% to
5%. There is currently no stormwater measure provided on the site. Located on the southend
of the property is an existing ditch that takes water from the property and directs it thru the
existing stream offsite. There is no off-site area examined in this analysis.

STORMWATER REQUIREMENTS AND DESIGN OVERVIEW

This project is located in the Eastern Catawba district and is adjacent to North Fork Crooked
Creek. This project is classified as a high-density project because each drainage area has
greater than 12% built upon area.

Stormwater quality treatment systems shall treat the runoff generated from the first inch of
rainfall.

All structural stormwater treatment systems used to meet these requirements shall be designed
to have a minimum of 85% average annual removal for total suspended solids and 70%
average annual removal for total phosphorus.

General engineering design criteria shall be accordance with 15 A NCAC 2H. 1008(c) in the
design manual.

The peak discharge is attenuated for both the 2-year, 24-hr storm and the 25-year, 24-hr storm
events. The 100-year, 24-hr storm event has been analyzed to provide 1’ of freeboard to the
top of berm.

Areas not controlled by systems due to topographic challenges are sheet flowing through the
vegetated buffer, but all proposed impervious areas are treated within the proposed stormwater
control measures.

Please note that all runoff from the roofs of the homes is to be routed to underground storm
drains that discharge into the wet detention pond. Some homes will have direct tie-ins of their
roof drains to nearby structures and some will flow overland and in channels to nearby inlets.

STORMSEWER DESIGN

Stormwater run-off from the site will be directed to the existing outfall locations via a system of
storm sewer pipes. The storm sewer was modeled in Hydraflow Storm Sewers Extension for

4

Autodesk AutoCAD Civil 3D. The storm sewer pipes were modeled to ensure their adequate
capacity with a minimum slope of 0.5% to promote flushing of the pipes.

Stormwater Management and BMP Calculations

PRE VS. POST ANALYSIS PEAK ATTENUATION

See table below for final flow calculations for the pre and post conditions. It should be noted
that time of concentration is accounted for in the summation of the combined peak discharge
values.

DRAINAGE AREA
2-YR 24
HR(cfs)
25-YR 24
HR(cfs)
POI 1 COMBINED:
PRE DA 1 20.16 46.62
POST DA 1 15.51 46.39
POI 2:
PRE DA 2 4.40 10.73
POST DA 2 1.98 4.85

All associated calculations have been provided within the Appendix section of this report.

WATER QUALITY

Water quality treatment of the 1” water quality volume, is also provided within the proposed
above-ground wet detention pond, and is to be detained between 2-5days (See appendix for
calculations).

5

Appendix
DESIGN:
GIVEN:
7.63 Ac.
65%
4.1 FEET
65%
SA/DA = 1.60 % = 0.0160 Updated MDC
SA REQUIRED = 7.63 Ac. X 0.0160
= 0.12 Ac.
= 5,316 SF
THE VOLUME FOR THE 1" STORM EVENT CAN BE CALCULATED AS:
Design Rainfall = 1 Inch
Drainage Area = 7.63 Acres
Rv = 0.05 + 0.9(I)
I = Percent Impervious = 65%
Rv = 0.64 in./in.
V1 =0.404 acre-feet = 17,607
ft3
Pond Height above Orifice = 625.41 feet
Orifice Invert Elevation = 623.50 feet
Orifice Diameter (D) = 2.00 inches = 0.17 feet
Orifice Area (a) = 0.0218 square feet
Gravitational Constant (g) = 32.2 ft/sec2
Head (H) = 1.83 feet
Driving Head (HO) =0.609 feet
Discharge Coefficient (CD) =0.6
Drawdown rate (Q) = 0.082 cfs
Time (t) = 214,806 seconds = 2.49 days
Note:
The above calculation is based on the orifice equation where:
3) Pond Drawdown Time
ALLOCATED AS A PERMANENT POOL
V1 = (Design Rainfall)(Rv)(Drainage Area)
WET POND #1 Poplin (Union county)
WATER QUALITY TO MEET 85% TSS REMOVAL
Self-Storage FacilityLAND USE =
ESTIMATED PERCENT IMPERVIOUS =
DRAINAGE AREA TO FACILITY =
AVERAGE POOL DEPTH =
1) SA/DA RATIO:
PROVIDE VOLUME TO DETAIN THE 1" STORM EVENT ABOVE THE ELEVATION
PERCENT IMPERVIOUS =
2) TEMPORARY WATER QUALITY POOL REQUIREMENTS
6/5/2018 3:55 PM Page 1 of 1
Elev Area (sf)Inc Storage (cf)Total Storage (cf)
623.50 8,755 0 0
624.50 10,050 9,403 9,403
625.50 11,405 10,728 20,130
626.50 12,815 12,110 32,240
627.50 14,275 13,545 45,785
628.50 15,800 15,038 60,823
629.50 17,380 16,590 77,413
Elev Area (sf) Inc Storage (cf) Total Storage (cf)
618.50 2,555 0 0
619.50 3,041 0 0
620.50 3,556 3,299 3,299
621.50 4,129 3,843 7,141
622.50 4,730 4,430 11,571
623.50 8,754 17,906 32,166
Elev Area (sf) Inc Storage (cf) Total Storage (cf)
618.50 359 0 0
619.50 539 0 0
620.50 757 648 648
621.50 1,011 884 1,532
622.50 1,303 1,157 2,689
Wet Pond 1 Design
Wet Pond 1 Treatment Volume
Wet Pond 1 Permanent Pool - Forebay
Wet Pond 1 Permanent Pool Volume - Main Pool
6/5/2018 3:56 PM Page 1 of 1
1S
Pre DA 1
2S
Pre DA 2
4S
Post DA 1 Controlled
7S
Post DA 1 Sheet Flow
8S
Post DA 2
5P
Pond 1
6L
POI 1 Combined
Routing Diagram for NCC172107 - Poplin Road - 180604 - ATZ
Prepared by Bohler Engineering, Printed 6/5/2018
HydroCAD® 10.00-20 s/n 03478 © 2017 HydroCAD Software Solutions LLC
Subcat Reach Pond Link
NCC172107 - Poplin Road - 180604 - ATZ
Printed 6/5/2018Prepared by Bohler Engineering
Page 2HydroCAD® 10.00-20 s/n 03478 © 2017 HydroCAD Software Solutions LLC
Area Listing (all nodes)
Area
(acres)
CN Description
(subcatchment-numbers)
3.060 61 >75% Grass cover, Good, HSG B (4S)
1.500 80 >75% Grass cover, Good, HSG D (7S)
7.150 80 Pasture/grassland/range, Good, HSG D (1S, 2S)
4.560 98 Paved roads w/curbs & sewers, HSG B (4S)
3.200 93 Paved roads w/open ditches, 50% imp, HSG D (1S, 7S)
6.850 77 Woods, Good, HSG D (1S, 2S, 7S, 8S)
26.320 82 TOTAL AREA
NCC172107 - Poplin Road - 180604 - ATZ
Printed 6/5/2018Prepared by Bohler Engineering
Page 3HydroCAD® 10.00-20 s/n 03478 © 2017 HydroCAD Software Solutions LLC
Soil Listing (all nodes)
Area
(acres)
Soil
Group
Subcatchment
Numbers
0.000 HSG A
7.620 HSG B 4S
0.000 HSG C
18.700 HSG D 1S, 2S, 7S, 8S
0.000 Other
26.320 TOTAL AREA
NCC172107 - Poplin Road - 180604 - ATZ
Printed 6/5/2018Prepared by Bohler Engineering
Page 4HydroCAD® 10.00-20 s/n 03478 © 2017 HydroCAD Software Solutions LLC
Ground Covers (all nodes)
HSG-A
(acres)
HSG-B
(acres)
HSG-C
(acres)
HSG-D
(acres)
Other
(acres)
Total
(acres)
Ground
Cover
Subcatchment
Numbers
0.000 3.060 0.000 1.500 0.000 4.560 >75% Grass cover, Good
0.000 0.000 0.000 7.150 0.000 7.150 Pasture/grassland/range, Good
0.000 4.560 0.000 0.000 0.000 4.560 Paved roads w/curbs & sewers
0.000 0.000 0.000 3.200 0.000 3.200 Paved roads w/open ditches, 50%
imp
0.000 0.000 0.000 6.850 0.000 6.850 Woods, Good
0.000 7.620 0.000 18.700 0.000 26.320 TOTAL AREA
NCC172107 - Poplin Road - 180604 - ATZ
Printed 6/5/2018Prepared by Bohler Engineering
Page 5HydroCAD® 10.00-20 s/n 03478 © 2017 HydroCAD Software Solutions LLC
Pipe Listing (all nodes)
Line# Node
Number
In-Invert
(feet)
Out-Invert
(feet)
Length
(feet)
Slope
(ft/ft)
n Diam/Width
(inches)
Height
(inches)
Inside-Fill
(inches)
1 5P 623.50 623.00 75.0 0.0067 0.011 18.0 0.0 0.0
Type II 24-hr 25-Year Rainfall=6.18"NCC172107 - Poplin Road - 180604 - ATZ
Printed 6/5/2018Prepared by Bohler Engineering
Page 6HydroCAD® 10.00-20 s/n 03478 © 2017 HydroCAD Software Solutions LLC
Time span=0.00-60.00 hrs, dt=0.05 hrs, 1201 points
Runoff by SCS TR-20 method, UH=SCS, Weighted-CN
Reach routing by Dyn-Stor-Ind method - Pond routing by Dyn-Stor-Ind method
Runoff Area=11.150 ac 7.17% Impervious Runoff Depth=4.05"Subcatchment 1S: Pre DA 1
Flow Length=1,778' Tc=22.4 min CN=81 Runoff=46.62 cfs 3.761 af
Runoff Area=2.200 ac 0.00% Impervious Runoff Depth=3.74"Subcatchment 2S: Pre DA 2
Flow Length=1,220' Tc=14.4 min CN=78 Runoff=10.73 cfs 0.685 af
Runoff Area=7.620 ac 59.84% Impervious Runoff Depth=4.26"Subcatchment 4S: Post DA 1 Controlled
Tc=5.0 min CN=83 Runoff=56.28 cfs 2.704 af
Runoff Area=4.600 ac 17.39% Impervious Runoff Depth=4.37"Subcatchment 7S: Post DA 1 Sheet Flow
Tc=10.0 min CN=84 Runoff=29.52 cfs 1.673 af
Runoff Area=0.750 ac 0.00% Impervious Runoff Depth=3.64"Subcatchment 8S: Post DA 2
Flow Length=260' Slope=0.0300 '/' Tc=5.0 min CN=77 Runoff=4.85 cfs 0.227 af
Peak Elev=627.77' Storage=50,459 cf Inflow=56.28 cfs 2.704 afPond 5P: Pond 1
Primary=17.36 cfs 2.616 af Secondary=0.00 cfs 0.000 af Outflow=17.36 cfs 2.616 af
Inflow=46.39 cfs 4.289 afLink 6L: POI 1 Combined
Primary=46.39 cfs 4.289 af
Total Runoff Area = 26.320 ac Runoff Volume = 9.052 af Average Runoff Depth = 4.13"
76.60% Pervious = 20.160 ac 23.40% Impervious = 6.160 ac
Type II 24-hr 25-Year Rainfall=6.18"NCC172107 - Poplin Road - 180604 - ATZ
Printed 6/5/2018Prepared by Bohler Engineering
Page 7HydroCAD® 10.00-20 s/n 03478 © 2017 HydroCAD Software Solutions LLC
Summary for Subcatchment 1S: Pre DA 1
Runoff = 46.62 cfs @ 12.15 hrs, Volume= 3.761 af, Depth= 4.05"
Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-60.00 hrs, dt= 0.05 hrs
Type II 24-hr 25-Year Rainfall=6.18"
Area (ac) CN Description
6.450 80 Pasture/grassland/range, Good, HSG D
3.100 77 Woods, Good, HSG D
1.600 93 Paved roads w/open ditches, 50% imp, HSG D
11.150 81 Weighted Average
10.350 92.83% Pervious Area
0.800 7.17% Impervious Area
Tc Length Slope Velocity Capacity Description
(min) (feet) (ft/ft) (ft/sec) (cfs)
11.5 150 0.0200 0.22 Sheet Flow,
Range n= 0.130 P2= 3.55"
3.4 200 0.0200 0.99 Shallow Concentrated Flow,
Short Grass Pasture Kv= 7.0 fps
7.5 1,428 0.0110 3.17 9.50 Channel Flow,
Area= 3.0 sf Perim= 5.0' r= 0.60'
n= 0.035 Earth, dense weeds
22.4 1,778 Total
Subcatchment 1S: Pre DA 1
Runoff
Hydrograph
Time (hours)
605856545250484644424038363432302826242220181614121086420Flow (cfs)52
50
48
46
44
42
40
38
36
34
32
30
28
26
24
22
20
18
16
14
12
10
8
6
4
2
0
Type II 24-hr
25-Year Rainfall=6.18"
Runoff Area=11.150 ac
Runoff Volume=3.761 af
Runoff Depth=4.05"
Flow Length=1,778'
Tc=22.4 min
CN=81
46.62 cfs
Type II 24-hr 25-Year Rainfall=6.18"NCC172107 - Poplin Road - 180604 - ATZ
Printed 6/5/2018Prepared by Bohler Engineering
Page 8HydroCAD® 10.00-20 s/n 03478 © 2017 HydroCAD Software Solutions LLC
Hydrograph for Subcatchment 1S: Pre DA 1
Time
(hours)
Precip.
(inches)
Excess
(inches)
Runoff
(cfs)
0.00 0.00 0.00 0.00
1.00 0.06 0.00 0.00
2.00 0.14 0.00 0.00
3.00 0.21 0.00 0.00
4.00 0.30 0.00 0.00
5.00 0.39 0.00 0.00
6.00 0.49 0.00 0.00
7.00 0.61 0.01 0.11
8.00 0.74 0.03 0.25
9.00 0.91 0.07 0.51
10.00 1.12 0.14 0.86
11.00 1.45 0.29 1.88
12.00 4.10 2.20 29.83
13.00 4.77 2.78 5.21
14.00 5.07 3.05 2.71
15.00 5.27 3.23 2.01
16.00 5.44 3.38 1.58
17.00 5.57 3.50 1.34
18.00 5.69 3.60 1.18
19.00 5.80 3.70 1.03
20.00 5.88 3.78 0.87
21.00 5.96 3.85 0.80
22.00 6.04 3.92 0.77
23.00 6.11 3.98 0.74
24.00 6.18 4.05 0.71
25.00 6.18 4.05 0.00
26.00 6.18 4.05 0.00
27.00 6.18 4.05 0.00
28.00 6.18 4.05 0.00
29.00 6.18 4.05 0.00
30.00 6.18 4.05 0.00
31.00 6.18 4.05 0.00
32.00 6.18 4.05 0.00
33.00 6.18 4.05 0.00
34.00 6.18 4.05 0.00
35.00 6.18 4.05 0.00
36.00 6.18 4.05 0.00
37.00 6.18 4.05 0.00
38.00 6.18 4.05 0.00
39.00 6.18 4.05 0.00
40.00 6.18 4.05 0.00
41.00 6.18 4.05 0.00
42.00 6.18 4.05 0.00
43.00 6.18 4.05 0.00
44.00 6.18 4.05 0.00
45.00 6.18 4.05 0.00
46.00 6.18 4.05 0.00
47.00 6.18 4.05 0.00
48.00 6.18 4.05 0.00
49.00 6.18 4.05 0.00
50.00 6.18 4.05 0.00
51.00 6.18 4.05 0.00
Time
(hours)
Precip.
(inches)
Excess
(inches)
Runoff
(cfs)
52.00 6.18 4.05 0.00
53.00 6.18 4.05 0.00
54.00 6.18 4.05 0.00
55.00 6.18 4.05 0.00
56.00 6.18 4.05 0.00
57.00 6.18 4.05 0.00
58.00 6.18 4.05 0.00
59.00 6.18 4.05 0.00
60.00 6.18 4.05 0.00
Type II 24-hr 25-Year Rainfall=6.18"NCC172107 - Poplin Road - 180604 - ATZ
Printed 6/5/2018Prepared by Bohler Engineering
Page 9HydroCAD® 10.00-20 s/n 03478 © 2017 HydroCAD Software Solutions LLC
Summary for Subcatchment 2S: Pre DA 2
Runoff = 10.73 cfs @ 12.06 hrs, Volume= 0.685 af, Depth= 3.74"
Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-60.00 hrs, dt= 0.05 hrs
Type II 24-hr 25-Year Rainfall=6.18"
Area (ac) CN Description
1.500 77 Woods, Good, HSG D
0.700 80 Pasture/grassland/range, Good, HSG D
2.200 78 Weighted Average
2.200 100.00% Pervious Area
Tc Length Slope Velocity Capacity Description
(min) (feet) (ft/ft) (ft/sec) (cfs)
6.4 100 0.0500 0.26 Sheet Flow,
Grass: Short n= 0.150 P2= 3.55"
3.0 860 0.0200 4.73 23.67 Channel Flow,
Area= 5.0 sf Perim= 9.0' r= 0.56'
n= 0.030 Earth, grassed & winding
5.0 260 0.0300 0.87 Shallow Concentrated Flow,
Woodland Kv= 5.0 fps
14.4 1,220 Total
Subcatchment 2S: Pre DA 2
Runoff
Hydrograph
Time (hours)
605856545250484644424038363432302826242220181614121086420Flow (cfs)12
11
10
9
8
7
6
5
4
3
2
1
0
Type II 24-hr
25-Year Rainfall=6.18"
Runoff Area=2.200 ac
Runoff Volume=0.685 af
Runoff Depth=3.74"
Flow Length=1,220'
Tc=14.4 min
CN=78
10.73 cfs
Type II 24-hr 25-Year Rainfall=6.18"NCC172107 - Poplin Road - 180604 - ATZ
Printed 6/5/2018Prepared by Bohler Engineering
Page 10HydroCAD® 10.00-20 s/n 03478 © 2017 HydroCAD Software Solutions LLC
Hydrograph for Subcatchment 2S: Pre DA 2
Time
(hours)
Precip.
(inches)
Excess
(inches)
Runoff
(cfs)
0.00 0.00 0.00 0.00
1.00 0.06 0.00 0.00
2.00 0.14 0.00 0.00
3.00 0.21 0.00 0.00
4.00 0.30 0.00 0.00
5.00 0.39 0.00 0.00
6.00 0.49 0.00 0.00
7.00 0.61 0.00 0.00
8.00 0.74 0.01 0.03
9.00 0.91 0.04 0.08
10.00 1.12 0.09 0.14
11.00 1.45 0.21 0.34
12.00 4.10 1.96 9.30
13.00 4.77 2.52 0.83
14.00 5.07 2.77 0.48
15.00 5.27 2.95 0.37
16.00 5.44 3.09 0.29
17.00 5.57 3.20 0.25
18.00 5.69 3.31 0.22
19.00 5.80 3.40 0.19
20.00 5.88 3.48 0.16
21.00 5.96 3.55 0.15
22.00 6.04 3.61 0.15
23.00 6.11 3.68 0.14
24.00 6.18 3.74 0.14
25.00 6.18 3.74 0.00
26.00 6.18 3.74 0.00
27.00 6.18 3.74 0.00
28.00 6.18 3.74 0.00
29.00 6.18 3.74 0.00
30.00 6.18 3.74 0.00
31.00 6.18 3.74 0.00
32.00 6.18 3.74 0.00
33.00 6.18 3.74 0.00
34.00 6.18 3.74 0.00
35.00 6.18 3.74 0.00
36.00 6.18 3.74 0.00
37.00 6.18 3.74 0.00
38.00 6.18 3.74 0.00
39.00 6.18 3.74 0.00
40.00 6.18 3.74 0.00
41.00 6.18 3.74 0.00
42.00 6.18 3.74 0.00
43.00 6.18 3.74 0.00
44.00 6.18 3.74 0.00
45.00 6.18 3.74 0.00
46.00 6.18 3.74 0.00
47.00 6.18 3.74 0.00
48.00 6.18 3.74 0.00
49.00 6.18 3.74 0.00
50.00 6.18 3.74 0.00
51.00 6.18 3.74 0.00
Time
(hours)
Precip.
(inches)
Excess
(inches)
Runoff
(cfs)
52.00 6.18 3.74 0.00
53.00 6.18 3.74 0.00
54.00 6.18 3.74 0.00
55.00 6.18 3.74 0.00
56.00 6.18 3.74 0.00
57.00 6.18 3.74 0.00
58.00 6.18 3.74 0.00
59.00 6.18 3.74 0.00
60.00 6.18 3.74 0.00
Type II 24-hr 25-Year Rainfall=6.18"NCC172107 - Poplin Road - 180604 - ATZ
Printed 6/5/2018Prepared by Bohler Engineering
Page 11HydroCAD® 10.00-20 s/n 03478 © 2017 HydroCAD Software Solutions LLC
Summary for Subcatchment 4S: Post DA 1 Controlled
[49] Hint: Tc<2dt may require smaller dt
Runoff = 56.28 cfs @ 11.95 hrs, Volume= 2.704 af, Depth= 4.26"
Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-60.00 hrs, dt= 0.05 hrs
Type II 24-hr 25-Year Rainfall=6.18"
Area (ac) CN Description
4.560 98 Paved roads w/curbs & sewers, HSG B
3.060 61 >75% Grass cover, Good, HSG B
7.620 83 Weighted Average
3.060 40.16% Pervious Area
4.560 59.84% Impervious Area
Tc Length Slope Velocity Capacity Description
(min) (feet) (ft/ft) (ft/sec) (cfs)
5.0 Direct Entry,
Subcatchment 4S: Post DA 1 Controlled
Runoff
Hydrograph
Time (hours)
605856545250484644424038363432302826242220181614121086420Flow (cfs)60
55
50
45
40
35
30
25
20
15
10
5
0
Type II 24-hr
25-Year Rainfall=6.18"
Runoff Area=7.620 ac
Runoff Volume=2.704 af
Runoff Depth=4.26"
Tc=5.0 min
CN=83
56.28 cfs
Type II 24-hr 25-Year Rainfall=6.18"NCC172107 - Poplin Road - 180604 - ATZ
Printed 6/5/2018Prepared by Bohler Engineering
Page 12HydroCAD® 10.00-20 s/n 03478 © 2017 HydroCAD Software Solutions LLC
Hydrograph for Subcatchment 4S: Post DA 1 Controlled
Time
(hours)
Precip.
(inches)
Excess
(inches)
Runoff
(cfs)
0.00 0.00 0.00 0.00
1.00 0.06 0.00 0.00
2.00 0.14 0.00 0.00
3.00 0.21 0.00 0.00
4.00 0.30 0.00 0.00
5.00 0.39 0.00 0.00
6.00 0.49 0.00 0.06
7.00 0.61 0.02 0.16
8.00 0.74 0.05 0.26
9.00 0.91 0.10 0.51
10.00 1.12 0.18 0.81
11.00 1.45 0.35 1.80
12.00 4.10 2.37 48.01
13.00 4.77 2.97 2.77
14.00 5.07 3.24 1.66
15.00 5.27 3.42 1.32
16.00 5.44 3.57 1.02
17.00 5.57 3.70 0.90
18.00 5.69 3.81 0.80
19.00 5.80 3.90 0.69
20.00 5.88 3.98 0.58
21.00 5.96 4.06 0.55
22.00 6.04 4.13 0.53
23.00 6.11 4.19 0.51
24.00 6.18 4.26 0.49
25.00 6.18 4.26 0.00
26.00 6.18 4.26 0.00
27.00 6.18 4.26 0.00
28.00 6.18 4.26 0.00
29.00 6.18 4.26 0.00
30.00 6.18 4.26 0.00
31.00 6.18 4.26 0.00
32.00 6.18 4.26 0.00
33.00 6.18 4.26 0.00
34.00 6.18 4.26 0.00
35.00 6.18 4.26 0.00
36.00 6.18 4.26 0.00
37.00 6.18 4.26 0.00
38.00 6.18 4.26 0.00
39.00 6.18 4.26 0.00
40.00 6.18 4.26 0.00
41.00 6.18 4.26 0.00
42.00 6.18 4.26 0.00
43.00 6.18 4.26 0.00
44.00 6.18 4.26 0.00
45.00 6.18 4.26 0.00
46.00 6.18 4.26 0.00
47.00 6.18 4.26 0.00
48.00 6.18 4.26 0.00
49.00 6.18 4.26 0.00
50.00 6.18 4.26 0.00
51.00 6.18 4.26 0.00
Time
(hours)
Precip.
(inches)
Excess
(inches)
Runoff
(cfs)
52.00 6.18 4.26 0.00
53.00 6.18 4.26 0.00
54.00 6.18 4.26 0.00
55.00 6.18 4.26 0.00
56.00 6.18 4.26 0.00
57.00 6.18 4.26 0.00
58.00 6.18 4.26 0.00
59.00 6.18 4.26 0.00
60.00 6.18 4.26 0.00
Type II 24-hr 25-Year Rainfall=6.18"NCC172107 - Poplin Road - 180604 - ATZ
Printed 6/5/2018Prepared by Bohler Engineering
Page 13HydroCAD® 10.00-20 s/n 03478 © 2017 HydroCAD Software Solutions LLC
Summary for Subcatchment 7S: Post DA 1 Sheet Flow
Runoff = 29.52 cfs @ 12.01 hrs, Volume= 1.673 af, Depth= 4.37"
Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-60.00 hrs, dt= 0.05 hrs
Type II 24-hr 25-Year Rainfall=6.18"
Area (ac) CN Description
1.500 77 Woods, Good, HSG D
1.500 80 >75% Grass cover, Good, HSG D
1.600 93 Paved roads w/open ditches, 50% imp, HSG D
4.600 84 Weighted Average
3.800 82.61% Pervious Area
0.800 17.39% Impervious Area
Tc Length Slope Velocity Capacity Description
(min) (feet) (ft/ft) (ft/sec) (cfs)
10.0 Direct Entry,
Subcatchment 7S: Post DA 1 Sheet Flow
Runoff
Hydrograph
Time (hours)
605856545250484644424038363432302826242220181614121086420Flow (cfs)32
30
28
26
24
22
20
18
16
14
12
10
8
6
4
2
0
Type II 24-hr
25-Year Rainfall=6.18"
Runoff Area=4.600 ac
Runoff Volume=1.673 af
Runoff Depth=4.37"
Tc=10.0 min
CN=84
29.52 cfs
Type II 24-hr 25-Year Rainfall=6.18"NCC172107 - Poplin Road - 180604 - ATZ
Printed 6/5/2018Prepared by Bohler Engineering
Page 14HydroCAD® 10.00-20 s/n 03478 © 2017 HydroCAD Software Solutions LLC
Hydrograph for Subcatchment 7S: Post DA 1 Sheet Flow
Time
(hours)
Precip.
(inches)
Excess
(inches)
Runoff
(cfs)
0.00 0.00 0.00 0.00
1.00 0.06 0.00 0.00
2.00 0.14 0.00 0.00
3.00 0.21 0.00 0.00
4.00 0.30 0.00 0.00
5.00 0.39 0.00 0.00
6.00 0.49 0.01 0.05
7.00 0.61 0.02 0.11
8.00 0.74 0.06 0.17
9.00 0.91 0.11 0.32
10.00 1.12 0.21 0.50
11.00 1.45 0.39 1.08
12.00 4.10 2.46 29.37
13.00 4.77 3.06 1.79
14.00 5.07 3.33 1.05
15.00 5.27 3.52 0.82
16.00 5.44 3.67 0.64
17.00 5.57 3.80 0.56
18.00 5.69 3.91 0.49
19.00 5.80 4.01 0.42
20.00 5.88 4.09 0.36
21.00 5.96 4.16 0.34
22.00 6.04 4.23 0.32
23.00 6.11 4.30 0.31
24.00 6.18 4.37 0.30
25.00 6.18 4.37 0.00
26.00 6.18 4.37 0.00
27.00 6.18 4.37 0.00
28.00 6.18 4.37 0.00
29.00 6.18 4.37 0.00
30.00 6.18 4.37 0.00
31.00 6.18 4.37 0.00
32.00 6.18 4.37 0.00
33.00 6.18 4.37 0.00
34.00 6.18 4.37 0.00
35.00 6.18 4.37 0.00
36.00 6.18 4.37 0.00
37.00 6.18 4.37 0.00
38.00 6.18 4.37 0.00
39.00 6.18 4.37 0.00
40.00 6.18 4.37 0.00
41.00 6.18 4.37 0.00
42.00 6.18 4.37 0.00
43.00 6.18 4.37 0.00
44.00 6.18 4.37 0.00
45.00 6.18 4.37 0.00
46.00 6.18 4.37 0.00
47.00 6.18 4.37 0.00
48.00 6.18 4.37 0.00
49.00 6.18 4.37 0.00
50.00 6.18 4.37 0.00
51.00 6.18 4.37 0.00
Time
(hours)
Precip.
(inches)
Excess
(inches)
Runoff
(cfs)
52.00 6.18 4.37 0.00
53.00 6.18 4.37 0.00
54.00 6.18 4.37 0.00
55.00 6.18 4.37 0.00
56.00 6.18 4.37 0.00
57.00 6.18 4.37 0.00
58.00 6.18 4.37 0.00
59.00 6.18 4.37 0.00
60.00 6.18 4.37 0.00
Type II 24-hr 25-Year Rainfall=6.18"NCC172107 - Poplin Road - 180604 - ATZ
Printed 6/5/2018Prepared by Bohler Engineering
Page 15HydroCAD® 10.00-20 s/n 03478 © 2017 HydroCAD Software Solutions LLC
Summary for Subcatchment 8S: Post DA 2
[49] Hint: Tc<2dt may require smaller dt
Runoff = 4.85 cfs @ 11.96 hrs, Volume= 0.227 af, Depth= 3.64"
Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-60.00 hrs, dt= 0.05 hrs
Type II 24-hr 25-Year Rainfall=6.18"
Area (ac) CN Description
0.750 77 Woods, Good, HSG D
0.750 100.00% Pervious Area
Tc Length Slope Velocity Capacity Description
(min) (feet) (ft/ft) (ft/sec) (cfs)
5.0 260 0.0300 0.87 Shallow Concentrated Flow,
Woodland Kv= 5.0 fps
Subcatchment 8S: Post DA 2
Runoff
Hydrograph
Time (hours)
605856545250484644424038363432302826242220181614121086420Flow (cfs)5
4
3
2
1
0
Type II 24-hr
25-Year Rainfall=6.18"
Runoff Area=0.750 ac
Runoff Volume=0.227 af
Runoff Depth=3.64"
Flow Length=260'
Slope=0.0300 '/'
Tc=5.0 min
CN=77
4.85 cfs
Type II 24-hr 25-Year Rainfall=6.18"NCC172107 - Poplin Road - 180604 - ATZ
Printed 6/5/2018Prepared by Bohler Engineering
Page 16HydroCAD® 10.00-20 s/n 03478 © 2017 HydroCAD Software Solutions LLC
Hydrograph for Subcatchment 8S: Post DA 2
Time
(hours)
Precip.
(inches)
Excess
(inches)
Runoff
(cfs)
0.00 0.00 0.00 0.00
1.00 0.06 0.00 0.00
2.00 0.14 0.00 0.00
3.00 0.21 0.00 0.00
4.00 0.30 0.00 0.00
5.00 0.39 0.00 0.00
6.00 0.49 0.00 0.00
7.00 0.61 0.00 0.00
8.00 0.74 0.01 0.01
9.00 0.91 0.03 0.03
10.00 1.12 0.08 0.05
11.00 1.45 0.19 0.12
12.00 4.10 1.89 4.19
13.00 4.77 2.43 0.25
14.00 5.07 2.68 0.15
15.00 5.27 2.85 0.12
16.00 5.44 2.99 0.09
17.00 5.57 3.11 0.08
18.00 5.69 3.21 0.07
19.00 5.80 3.30 0.06
20.00 5.88 3.38 0.05
21.00 5.96 3.45 0.05
22.00 6.04 3.51 0.05
23.00 6.11 3.58 0.05
24.00 6.18 3.64 0.05
25.00 6.18 3.64 0.00
26.00 6.18 3.64 0.00
27.00 6.18 3.64 0.00
28.00 6.18 3.64 0.00
29.00 6.18 3.64 0.00
30.00 6.18 3.64 0.00
31.00 6.18 3.64 0.00
32.00 6.18 3.64 0.00
33.00 6.18 3.64 0.00
34.00 6.18 3.64 0.00
35.00 6.18 3.64 0.00
36.00 6.18 3.64 0.00
37.00 6.18 3.64 0.00
38.00 6.18 3.64 0.00
39.00 6.18 3.64 0.00
40.00 6.18 3.64 0.00
41.00 6.18 3.64 0.00
42.00 6.18 3.64 0.00
43.00 6.18 3.64 0.00
44.00 6.18 3.64 0.00
45.00 6.18 3.64 0.00
46.00 6.18 3.64 0.00
47.00 6.18 3.64 0.00
48.00 6.18 3.64 0.00
49.00 6.18 3.64 0.00
50.00 6.18 3.64 0.00
51.00 6.18 3.64 0.00
Time
(hours)
Precip.
(inches)
Excess
(inches)
Runoff
(cfs)
52.00 6.18 3.64 0.00
53.00 6.18 3.64 0.00
54.00 6.18 3.64 0.00
55.00 6.18 3.64 0.00
56.00 6.18 3.64 0.00
57.00 6.18 3.64 0.00
58.00 6.18 3.64 0.00
59.00 6.18 3.64 0.00
60.00 6.18 3.64 0.00
Type II 24-hr 25-Year Rainfall=6.18"NCC172107 - Poplin Road - 180604 - ATZ
Printed 6/5/2018Prepared by Bohler Engineering
Page 17HydroCAD® 10.00-20 s/n 03478 © 2017 HydroCAD Software Solutions LLC
Summary for Pond 5P: Pond 1
Inflow Area = 7.620 ac, 59.84% Impervious, Inflow Depth = 4.26" for 25-Year event
Inflow = 56.28 cfs @ 11.95 hrs, Volume= 2.704 af
Outflow = 17.36 cfs @ 12.09 hrs, Volume= 2.616 af, Atten= 69%, Lag= 7.9 min
Primary = 17.36 cfs @ 12.09 hrs, Volume= 2.616 af
Secondary = 0.00 cfs @ 0.00 hrs, Volume= 0.000 af
Routing by Dyn-Stor-Ind method, Time Span= 0.00-60.00 hrs, dt= 0.05 hrs
Peak Elev= 627.77' @ 12.09 hrs Surf.Area= 14,890 sf Storage= 50,459 cf
Plug-Flow detention time= 290.7 min calculated for 2.614 af (97% of inflow)
Center-of-Mass det. time= 272.9 min ( 1,074.0 - 801.1 )
Volume Invert Avail.Storage Storage Description
#1 623.50' 78,405 cf Above Permanent Pool (Prismatic) Listed below (Recalc)
Elevation Surf.Area Inc.Store Cum.Store
(feet) (sq-ft) (cubic-feet) (cubic-feet)
623.50 8,755 0 0
629.50 17,380 78,405 78,405
Device Routing Invert Outlet Devices
#1 Primary 623.50'18.0" Round Culvert
L= 75.0' RCP, groove end w/headwall, Ke= 0.200
Inlet / Outlet Invert= 623.50' / 623.00' S= 0.0067 '/' Cc= 0.900
n= 0.011 Concrete pipe, straight & clean, Flow Area= 1.77 sf
#2 Device 1 623.50'2.2" Vert. Orifice/Grate C= 0.600
#3 Device 1 625.41'36.0" W x 28.0" H Vert. Orifice/Grate C= 0.600
#4 Device 1 627.75'20.0' long Sharp-Crested Rectangular Weir 2 End Contraction(s)
#5 Secondary 628.25'70.0' long x 10.0' breadth Broad-Crested Rectangular Weir
Head (feet) 0.20 0.40 0.60 0.80 1.00 1.20 1.40 1.60
Coef. (English) 2.49 2.56 2.70 2.69 2.68 2.69 2.67 2.64
Primary OutFlow Max=17.33 cfs @ 12.09 hrs HW=627.76' TW=0.00' (Dynamic Tailwater)
1=Culvert (Barrel Controls 17.33 cfs @ 9.81 fps)
2=Orifice/Grate (Passes < 0.26 cfs potential flow)
3=Orifice/Grate (Passes < 34.62 cfs potential flow)
4=Sharp-Crested Rectangular Weir (Passes < 0.04 cfs potential flow)
Secondary OutFlow Max=0.00 cfs @ 0.00 hrs HW=623.50' TW=0.00' (Dynamic Tailwater)
5=Broad-Crested Rectangular Weir ( Controls 0.00 cfs)
Type II 24-hr 25-Year Rainfall=6.18"NCC172107 - Poplin Road - 180604 - ATZ
Printed 6/5/2018Prepared by Bohler Engineering
Page 18HydroCAD® 10.00-20 s/n 03478 © 2017 HydroCAD Software Solutions LLC
Pond 5P: Pond 1
Inflow
Outflow
Primary
Secondary
Hydrograph
Time (hours)
605856545250484644424038363432302826242220181614121086420Flow (cfs)60
55
50
45
40
35
30
25
20
15
10
5
0
Inflow Area=7.620 ac
Peak Elev=627.77'
Storage=50,459 cf
56.28 cfs
17.36 cfs
17.36 cfs
0.00 cfs
Pond 5P: Pond 1
Total
Primary
Secondary
Stage-Discharge
Discharge (cfs)
250200150100500Elevation (feet)629
628
627
626
625
624 Culvert + Orifice/Grate
Orifice/Grate
Sharp-Crested Rectangular Weir
Broad-Crested Rectangular Weir
Type II 24-hr 25-Year Rainfall=6.18"NCC172107 - Poplin Road - 180604 - ATZ
Printed 6/5/2018Prepared by Bohler Engineering
Page 19HydroCAD® 10.00-20 s/n 03478 © 2017 HydroCAD Software Solutions LLC
Pond 5P: Pond 1
Surface
Storage
Stage-Area-Storage
Storage (cubic-feet)
75,00070,00065,00060,00055,00050,00045,00040,00035,00030,00025,00020,00015,00010,0005,0000
Surface/Horizontal/Wetted Area (sq-ft)
16,00014,00012,00010,0008,0006,0004,0002,0000
Elevation (feet)629
628
627
626
625
624
Above Permanent Pool
Type II 24-hr 25-Year Rainfall=6.18"NCC172107 - Poplin Road - 180604 - ATZ
Printed 6/5/2018Prepared by Bohler Engineering
Page 20HydroCAD® 10.00-20 s/n 03478 © 2017 HydroCAD Software Solutions LLC
Hydrograph for Pond 5P: Pond 1
Time
(hours)
Inflow
(cfs)
Storage
(cubic-feet)
Elevation
(feet)
Outflow
(cfs)
Primary
(cfs)
Secondary
(cfs)
0.00 0.00 0 623.50 0.00 0.00 0.00
2.50 0.00 0 623.50 0.00 0.00 0.00
5.00 0.00 0 623.50 0.00 0.00 0.00
7.50 0.21 764 623.59 0.01 0.01 0.00
10.00 0.81 4,381 623.98 0.08 0.08 0.00
12.50 4.41 36,868 626.81 14.59 14.59 0.00
15.00 1.32 22,421 625.67 1.48 1.48 0.00
17.50 0.85 21,429 625.59 0.91 0.91 0.00
20.00 0.58 20,885 625.54 0.64 0.64 0.00
22.50 0.52 20,636 625.52 0.54 0.54 0.00
25.00 0.00 19,544 625.43 0.19 0.19 0.00
27.50 0.00 18,013 625.29 0.17 0.17 0.00
30.00 0.00 16,550 625.16 0.16 0.16 0.00
32.50 0.00 15,145 625.04 0.15 0.15 0.00
35.00 0.00 13,800 624.91 0.15 0.15 0.00
37.50 0.00 12,516 624.79 0.14 0.14 0.00
40.00 0.00 11,294 624.68 0.13 0.13 0.00
42.50 0.00 10,134 624.56 0.13 0.13 0.00
45.00 0.00 9,037 624.46 0.12 0.12 0.00
47.50 0.00 8,006 624.35 0.11 0.11 0.00
50.00 0.00 7,039 624.26 0.10 0.10 0.00
52.50 0.00 6,140 624.16 0.10 0.10 0.00
55.00 0.00 5,307 624.08 0.09 0.09 0.00
57.50 0.00 4,543 624.00 0.08 0.08 0.00
60.00 0.00 3,848 623.92 0.07 0.07 0.00
Type II 24-hr 25-Year Rainfall=6.18"NCC172107 - Poplin Road - 180604 - ATZ
Printed 6/5/2018Prepared by Bohler Engineering
Page 21HydroCAD® 10.00-20 s/n 03478 © 2017 HydroCAD Software Solutions LLC
Stage-Discharge for Pond 5P: Pond 1
Elevation
(feet)
Discharge
(cfs)
Primary
(cfs)
Secondary
(cfs)
623.50 0.00 0.00 0.00
623.60 0.02 0.02 0.00
623.70 0.04 0.04 0.00
623.80 0.06 0.06 0.00
623.90 0.07 0.07 0.00
624.00 0.08 0.08 0.00
624.10 0.09 0.09 0.00
624.20 0.10 0.10 0.00
624.30 0.11 0.11 0.00
624.40 0.11 0.11 0.00
624.50 0.12 0.12 0.00
624.60 0.13 0.13 0.00
624.70 0.13 0.13 0.00
624.80 0.14 0.14 0.00
624.90 0.15 0.15 0.00
625.00 0.15 0.15 0.00
625.10 0.16 0.16 0.00
625.20 0.16 0.16 0.00
625.30 0.17 0.17 0.00
625.40 0.17 0.17 0.00
625.50 0.44 0.44 0.00
625.60 0.98 0.98 0.00
625.70 1.69 1.69 0.00
625.80 2.53 2.53 0.00
625.90 3.50 3.50 0.00
626.00 4.56 4.56 0.00
626.10 5.72 5.72 0.00
626.20 6.97 6.97 0.00
626.30 8.29 8.29 0.00
626.40 9.70 9.70 0.00
626.50 11.18 11.18 0.00
626.60 12.72 12.72 0.00
626.70 14.24 14.24 0.00
626.80 14.56 14.56 0.00
626.90 14.87 14.87 0.00
627.00 15.18 15.18 0.00
627.10 15.48 15.48 0.00
627.20 15.77 15.77 0.00
627.30 16.06 16.06 0.00
627.40 16.35 16.35 0.00
627.50 16.63 16.63 0.00
627.60 16.90 16.90 0.00
627.70 17.17 17.17 0.00
627.80 17.44 17.44 0.00
627.90 17.70 17.70 0.00
628.00 17.96 17.96 0.00
628.10 18.22 18.22 0.00
628.20 18.47 18.47 0.00
628.30 20.66 18.71 1.95
628.40 29.08 18.96 10.13
628.50 41.14 19.20 21.94
628.60 56.29 19.44 36.85
Elevation
(feet)
Discharge
(cfs)
Primary
(cfs)
Secondary
(cfs)
628.70 74.51 19.67 54.83
628.80 96.00 19.91 76.09
628.90 119.09 20.14 98.95
629.00 142.78 20.37 122.42
629.10 168.02 20.59 147.43
629.20 194.68 20.81 173.87
629.30 223.07 21.03 202.03
629.40 253.25 21.25 232.00
629.50 284.14 21.47 262.67
Type II 24-hr 25-Year Rainfall=6.18"NCC172107 - Poplin Road - 180604 - ATZ
Printed 6/5/2018Prepared by Bohler Engineering
Page 22HydroCAD® 10.00-20 s/n 03478 © 2017 HydroCAD Software Solutions LLC
Stage-Area-Storage for Pond 5P: Pond 1
Elevation
(feet)
Surface
(sq-ft)
Storage
(cubic-feet)
623.50 8,755 0
623.60 8,899 883
623.70 9,043 1,780
623.80 9,186 2,691
623.90 9,330 3,617
624.00 9,474 4,557
624.10 9,618 5,512
624.20 9,761 6,481
624.30 9,905 7,464
624.40 10,049 8,462
624.50 10,193 9,474
624.60 10,336 10,500
624.70 10,480 11,541
624.80 10,624 12,596
624.90 10,767 13,666
625.00 10,911 14,750
625.10 11,055 15,848
625.20 11,199 16,961
625.30 11,342 18,088
625.40 11,486 19,229
625.50 11,630 20,385
625.60 11,774 21,555
625.70 11,918 22,740
625.80 12,061 23,939
625.90 12,205 25,152
626.00 12,349 26,380
626.10 12,493 27,622
626.20 12,636 28,878
626.30 12,780 30,149
626.40 12,924 31,434
626.50 13,068 32,734
626.60 13,211 34,048
626.70 13,355 35,376
626.80 13,499 36,719
626.90 13,642 38,076
627.00 13,786 39,447
627.10 13,930 40,833
627.20 14,074 42,233
627.30 14,217 43,648
627.40 14,361 45,077
627.50 14,505 46,520
627.60 14,649 47,978
627.70 14,793 49,450
627.80 14,936 50,936
627.90 15,080 52,437
628.00 15,224 53,952
628.10 15,368 55,482
628.20 15,511 57,026
628.30 15,655 58,584
628.40 15,799 60,157
628.50 15,943 61,744
628.60 16,086 63,345
Elevation
(feet)
Surface
(sq-ft)
Storage
(cubic-feet)
628.70 16,230 64,961
628.80 16,374 66,591
628.90 16,517 68,236
629.00 16,661 69,895
629.10 16,805 71,568
629.20 16,949 73,256
629.30 17,092 74,958
629.40 17,236 76,674
629.50 17,380 78,405
Type II 24-hr 25-Year Rainfall=6.18"NCC172107 - Poplin Road - 180604 - ATZ
Printed 6/5/2018Prepared by Bohler Engineering
Page 23HydroCAD® 10.00-20 s/n 03478 © 2017 HydroCAD Software Solutions LLC
Summary for Link 6L: POI 1 Combined
Inflow Area = 12.220 ac, 43.86% Impervious, Inflow Depth > 4.21" for 25-Year event
Inflow = 46.39 cfs @ 12.02 hrs, Volume= 4.289 af
Primary = 46.39 cfs @ 12.02 hrs, Volume= 4.289 af, Atten= 0%, Lag= 0.0 min
Primary outflow = Inflow, Time Span= 0.00-60.00 hrs, dt= 0.05 hrs
Link 6L: POI 1 Combined
Inflow
Primary
Hydrograph
Time (hours)
605856545250484644424038363432302826242220181614121086420Flow (cfs)50
45
40
35
30
25
20
15
10
5
0
Inflow Area=12.220 ac
46.39 cfs
46.39 cfs
Type II 24-hr 25-Year Rainfall=6.18"NCC172107 - Poplin Road - 180604 - ATZ
Printed 6/5/2018Prepared by Bohler Engineering
Page 24HydroCAD® 10.00-20 s/n 03478 © 2017 HydroCAD Software Solutions LLC
Hydrograph for Link 6L: POI 1 Combined
Time
(hours)
Inflow
(cfs)
Elevation
(feet)
Primary
(cfs)
0.00 0.00 0.00 0.00
1.00 0.00 0.00 0.00
2.00 0.00 0.00 0.00
3.00 0.00 0.00 0.00
4.00 0.00 0.00 0.00
5.00 0.00 0.00 0.00
6.00 0.05 0.00 0.05
7.00 0.11 0.00 0.11
8.00 0.20 0.00 0.20
9.00 0.38 0.00 0.38
10.00 0.58 0.00 0.58
11.00 1.19 0.00 1.19
12.00 45.98 0.00 45.98
13.00 6.88 0.00 6.88
14.00 3.17 0.00 3.17
15.00 2.30 0.00 2.30
16.00 1.80 0.00 1.80
17.00 1.53 0.00 1.53
18.00 1.35 0.00 1.35
19.00 1.17 0.00 1.17
20.00 1.00 0.00 1.00
21.00 0.91 0.00 0.91
22.00 0.87 0.00 0.87
23.00 0.84 0.00 0.84
24.00 0.80 0.00 0.80
25.00 0.19 0.00 0.19
26.00 0.17 0.00 0.17
27.00 0.17 0.00 0.17
28.00 0.16 0.00 0.16
29.00 0.16 0.00 0.16
30.00 0.16 0.00 0.16
31.00 0.16 0.00 0.16
32.00 0.15 0.00 0.15
33.00 0.15 0.00 0.15
34.00 0.15 0.00 0.15
35.00 0.15 0.00 0.15
36.00 0.14 0.00 0.14
37.00 0.14 0.00 0.14
38.00 0.14 0.00 0.14
39.00 0.14 0.00 0.14
40.00 0.13 0.00 0.13
41.00 0.13 0.00 0.13
42.00 0.13 0.00 0.13
43.00 0.12 0.00 0.12
44.00 0.12 0.00 0.12
45.00 0.12 0.00 0.12
46.00 0.12 0.00 0.12
47.00 0.11 0.00 0.11
48.00 0.11 0.00 0.11
49.00 0.11 0.00 0.11
50.00 0.10 0.00 0.10
51.00 0.10 0.00 0.10
Time
(hours)
Inflow
(cfs)
Elevation
(feet)
Primary
(cfs)
52.00 0.10 0.00 0.10
53.00 0.09 0.00 0.09
54.00 0.09 0.00 0.09
55.00 0.09 0.00 0.09
56.00 0.09 0.00 0.09
57.00 0.08 0.00 0.08
58.00 0.08 0.00 0.08
59.00 0.08 0.00 0.08
60.00 0.07 0.00 0.07
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Temporary Sediment Trap
Okay
0.54 Disturbed Area (Acres)
1.6 Peak Flow from 10-year Storm (cfs)
1944 Required Volume ft3
697 Required Surface Area ft2
18.7 Suggested Width ft
37.3 Suggested Length ft
20 Trial Top Width at Spillway Invert ft
50 Trial Top Length at Spillway Invert ft
2 Trial Side Slope Ratio Z:1
3.5 Trial Depth ft (1.5 feet below grade + 2 to 3.5 feet above grade)
6 Bottom Width ft
36 Bottom Length ft
216 Bottom Area ft2
2014 Actual Volume ft3 Okay
1000 Actual Surface Area ft2 Okay
5 Trial Weir Length ft
0.5 Trial Depth of Flow ft
5.3 Spillway Capacity cfs Okay
Q = ciA
6.38 Disturbed Area (Acres) i 3.67
14.0 Peak Flow from 10-year Storm (cfs) C 0.6
11484 Required Volume ft3
4566 Required Surface Area ft2
47.8 Suggested Width ft
95.6 Suggested Length ft
100 Trial Top Width at Spillway Invert ft
173 Trial Top Length at Spillway Invert ft
3 Trial Side Slope Ratio Z:1
11 Trial Depth ft (2 to 13 feet above grade)
34 Bottom Width ft
107 Bottom Length ft
3638 Bottom Area ft2
112268 Actual Volume ft3 Okay
17380 Actual Surface Area ft2 Okay
70 Trial Weir Length ft
0.5 Trial Depth of Flow ft
74.2 Spillway Capacity cfs Okay
2 Skimmer Size (inches) Skimmer Size
0.167 Head on Skimmer (feet) (Inches)
2.25 Orifice Size (1/4 inch increments) 1.5
2.40 Dewatering Time (days) 2
Suggest about 3 days 2.5
3
4
5
6
8
SKIMMER BASIN #1
Poplin Meadows
Project:
Location:
Project Number:
Date:
Designed:ATZ
Checked:MT
Outlet ID:
Pipe diameter=36 inches
Pipe slope=0.5 %
Roughness Coef.=0.013
Full Flow Capacity=52.02 cfs
Full flow velocity=7.36 ft/sec
Zone from graph above =3
Is grade of apron 10% or more:n Y/N
3 Length =24.0 ft.
Outlet pipe diameter=36 in.Width at Outlet =9.0 ft.
Outlet flowrate=52.0 cfs Width at end of Pad=36.7 ft.
Outlet velocity=7.36 ft/sec Stone diameter =10 in.
Material =Class I Thickness =15 in.
Zone Material Diameter Thickness Length
1 Class A 4 6 4 x D(o)
2 Class B 8 12 6 x D(o)
3 Class I 10 15 8 x D(o)
4 Class I 10 15 8 x D(o)
5 Class II 14 21 10 x D(o)
6 Class II 14 21 10 x D(o)
7
Calculations based on NY DOT method - Pages 8.06.05 through 8.06.06 in NC Erosion Control Manual
Special study required
Jun-07-2018
RRA
Inlcudes 1.1 Factor of Safety
Zone used =
NCC172107
Riprap Outlet Protection Design
Poplin Subdivision
Indian Trail, NC
7.4 ft/sec
0
5
10
15
20
25
0 1 2 3 4 5 6 7 8 9 10Velocity (ft/sec)Pipe diameter (ft)
Figure 8.06.b.1
Zone 1
Zone 2
Zone 3
Zone 4
Zone 5
Zone 6
Zone 7
Project:
Location:
Project Number:
Date:
Designed:ATZ
Checked:MT
Outlet ID:
Pipe diameter=15 inches
Pipe slope=0.5 %
Roughness Coef.=0.013
Full Flow Capacity=5.04 cfs
Full flow velocity=4.11 ft/sec
Zone from graph above =1
Is grade of apron 10% or more:n Y/N
1 Length =5.0 ft.
Outlet pipe diameter=15 in.Width at Outlet =3.8 ft.
Outlet flowrate=5.0 cfs Width at end of Pad=9.5 ft.
Outlet velocity=4.11 ft/sec Stone diameter =4 in.
Material =Class A Thickness =6 in.
Zone Material Diameter Thickness Length
1 Class A 4 6 4 x D(o)
2 Class B 8 12 6 x D(o)
3 Class I 10 15 8 x D(o)
4 Class I 10 15 8 x D(o)
5 Class II 14 21 10 x D(o)
6 Class II 14 21 10 x D(o)
7
Calculations based on NY DOT method - Pages 8.06.05 through 8.06.06 in NC Erosion Control Manual
NCC172107
Riprap Outlet Protection Design
Poplin Subdivision
Indian Trail, NC
Special study required
Jun-07-2018
RRB
Inlcudes 1.1 Factor of Safety
Zone used =
4.1 ft/sec
0
5
10
15
20
25
0 1 2 3 4 5 6 7 8 9 10Velocity (ft/sec)Pipe diameter (ft)
Figure 8.06.b.1
Zone 1
Zone 2
Zone 3
Zone 4
Zone 5
Zone 6
Zone 7