20190121 Ver 1_Stormwater Design Report_20190124

STORMWATER DESIGN REPORT
LAYH ILL ESTAES
PIN:0782242036,0782149065
SW PERMIT NUMBER: S-4606
SUBDIVISION NUMBER: PLG -001113-2018
IC Engineering, Inc.
Jan. 16th, 2019
'i1`��•�Fya�S�46*��'9'
SEAL
308
PDF processed with CutePDF evaluation edition www.CutePDF.com

LAYHILL ESTATES
STORMWATER DESIGN NARRATIVE
INTRODUCTION
This Site is located at the end of Layhill Drive, with the Property Number: 0782242036 just
north of the hammer head, and east of Yates Mill Pond Road(SR 1382). Please refer to the
construction drawings for the location map.
Natural resource information was obtained from available sources including USGS topographic
mapping, www.nconemap.com, www.ncfloodmaps.com and the City of Raleigh GIS department.
Topographic mapping served as base for the pre -development drainage map and analyzing
existing drainage patterns. The existing runoff from the area flows northeast from a high point
just south of the project site. (see existing drainage map exhibit) Most of this runoff is conveyed
to the existing stream; Yates Branch (Basin 20, Stream 13) There are floodplain encroachments on
the property, and are shown in the drainage maps.
The parent tract of land is 15.47Acres, 7.62 Acres will be developed in the 1 st phase, and lies in
Wake County Jurisdiction, in the Swift Creek LMP Watershed. Land -use in the upstream
watershed is currently comprised of primarily forest and residential land. The current zoning for
the Site is R -40W.
The project scope will consist of improvements to six(6) lots and the road extension to access
these lots. The following summary describes the measures used to meet the Runoff
Requirements listed in the Wake County Stormwater Design Manual.
The proposed Extended Dry pond is located near the property boundary where the slopes are
relatively flat. A Grass Swale will convey runoff to the Extended dry pond. These proposed
bmps will reduce nutrient runoff into the adjacent streams, and adhere to the Performance
Standards for the Swift Creek Watershed.

The project site is made up of five types of soils, as shown in the map below are assigned from
the https://maps.raleighnc.gov/iMAPS, Soil Survey). Information describing each one of the soil
types is listed below.
The majority of the soil around these bmps consists mostly of sandy loam soils that if left in its
natural state has trouble draining, these are categorized as hydraulic soil type D/B. After
construction of the bmps these Cecil and Pacolet soils show low potential for flooding and are
categorized as hydraulic soil type B, with relatively unimpeded transmission of water through the
soil. The Yates Branch stream, and its tributaries were determined to be part of the Swift Creek
riparian buffer jurisdiction and are shown in the construction drawings.
Calculations for the SCM and Erosion Control measures are included in this document, as well
as the Wake County Stormwater Design Tool spreadsheet. The Target Curved Number was not
achieved therefore attenuation will be required.
Soil types for Proposed Lots (Hydrologic soil group,)
WyA - Worsham sandy loam, 0 to 3% slopes, Hydric soil type D
CgC2 - Cecil gravelly sandy loam, 6 to 10% percent slopes, Moderately eroded, Hydric soil type
B
CeB2 - Cecil sandy loam, 2 to 6% percent slopes, Moderately eroded, Hydric soil type B
PaF - Pacolet sandy loam, 15 to 45% percent slopes, Hydric soil type B
CmA - Chewacla sandy loam, 0 to 2% percent slopes, Frequently flooded, Hydric soil type B/D
The map units were delineated by the Wake County Soil Survey, the property boundary is shown
in red dashed line.

EROSION CONTROL NARRATIVE
Site Description
The site has rolling topography with slopes generally 7 to 10%. Natural slopes steepen to 15 to
25% in the watershed watersupply buffer along the Yates Branch Creek. The site is now covered
with heavy, woody vegetation, predominately deciduous trees. There is no evidence of
significant erosion under present site conditions. The creek runs through the middle of the
property to the east of the proposed Layhill Dr extension. The 100' water supply watershed
buffer will not be encroached upon for this construction.
Adjacent Property
Land use in the vicinity is residential. The land immediately to the west north has been approved
for 1 acre single family lots. Areas to the south and west have been developed as single family
lots. The property to the east is a mobile park under Raleigh's ETJ.
Soils
3
5516 Nur Ln. Raleigh NC 27606 1919.271.0051 1 www.lCengineeringlnc.com
[e-mail]

The soil in the project area is mapped as Cecil and Durham in the soil survey. Upland soils on
site were sandy loam or silt loam near the soil surface and clay in the subsoil.
Due to the low permeability of the subsoil that will be exposed during grading, a surface wetness
problem with high runoff is anticipated following significant rainfall events. No groundwater
problem is expected during construction. The tight clay in the subsoil will make vegetation
difficult to establish. Topsoil exists on-site and will be stockpiled for use in landscaping.
S&EC Measures
Sediment control measures will be taken to prevent damage to Yates Branch Creek.
Approximately 1 acre of wooded area to the west contributes runoff into the construction area.
Sediment ponds will be located on either side of the proposed roadway at the low point before
the runoff leaves the site. Temporary erosion control ditches will be provided to route runoff
through sediment ponds. Limits of disturbance will be delineated with silt/tree protection fence
and silt fence outlets will be provided as needed. The 25 -yr storm event will be used in
determining the surface area for each basin, (Swift Creek Water Supply District.)
Sediment Trap Sizing
2:1 length to width
V=3600 cu .ft. per acre
SA>435*Q25
DA<5.0 ac
Name
Drainage Volume
Surface
L x W x D@ TOB
area
Area
ST -1
2.64 ac 4068 cu. ft.
2250 SF
77'x 32'x 3'
ST -2
0.40 ac 2008 cu. ft.
1160 SF
60' x 22' x 3'
ST -3
0.35 ac 2008 cu. ft.
1160 SF
60' x 22' x 3'

P=
WAKE
COUNTY
NORTH CAROLINA
SITE DATA
Wake County Stormwater Hybrid Tool Version 2.2
Project Information
Project Name:
Layhill Estates
Permit No (if known):
PLG -001113-2018
Applicant:
IC Engineering, Inc
Applicant Contact Name:
Joe Ogden, P.E.
Applicant Contact Number:
919-948-9590
Contact Email:
k.alzoubila)icengineeringi Lc=
Last Modified Date:
Tuesday, January 15, 2019
Site Data:
River Basin:
Neuse
Regulatory Watershed:
Swift
Physiographic/Geologic Region:
Piedmont
Type of Development (Select from Dropdown menu):
Residential
Zoning:
R -40W
Total Site Area (Ac):
5.28
Existing Lake/Pond Area (Ac):
0.00
Proposed Disturbed Area (Ac):
1.96
Proposed Impervious Surface Area from DA Sheets (acre):
1.56
Percent Built Upon Area (BUA):
30%
Is the proposed project a site expansion?
No
Number of Drainage Areas on Site (Points of Analysis):
1
Annual Rainfall (in):
45.41
One-year, 24-hour rainfall (in):
3.00
Two-year, 24-hour rainfall (in):
3.60
Proposed Residential Stormwater Details (if applicable):
Site Square Footage:
229,997
Total Acreage in Lots:
6.92
Lot Square Footage:
301,435
Number of Lots:
6
Average Lot Size (SF):
51,110
Proposed Impervious Surface Area from DA sheets (SF):
67,954
Proposed Impervious Surface Area Devoted to Lots (SF):
56,628
Total Impervious Surface Area Devoted to Roads (SF):
13,919
Other Impervious Surface Area (SF):
53,143
Page 1

W akeCountySlormwalerDesignTcoN2.2
Project Name: La hill Estates
�V1� DRAINAGE AREA 1
WAKE STORMWATER PRE -POST CALCULATIONS
COUNTY
LAND USE & SITE DATA
PRE -DEVELOPMENT
POST -DEVELOPMENT
Drainage Area (Acres)=
5.50
5.50
She Acreage within Drainage=
5.28
5.28
One-year, 24-hour rainfall (in)=
3.00
Land Use (acres) by Soil Group:
ASoils
B Solis C Solis
D Solis ASoils
B Solis C Solis
D Solis
Commercial
Site Offstte
She Offske Site Offske
Site Offske She Offsite
Site Offsite Site Offsite
She Offsite
Parking lot
Roof
OpeNLandscaped
Industrial
Site Offsite
She Offsite Site Offsite
Site Offsite She Offsite
Site Offsite Site Offsite
She Offsite
Parking lot
Roof
OpeNLandscaped
Tramportai
High Density (interstate, main)
Site Offsite
She Offske Site Offsite
Site Offske She Offsite
Site Offsite Site Offske
She Offsite
High Density (Grassed Right-of-ways)
Lox Density (secondary, feeder)
Lox Density (Grassed Right-of-ways)
Rural
Rural (Grassed Right -d -ways)
Sidewalk
I
Mise. Pervious
Site I Offsite
Site Offske Site Offsite
Site Offske Site Offsite
Site Offsite Site Offsite
Site Offsite
Managed pervious (Open Space)
Unmanaged (pasture)
Woods (nut on Ids)
Residential
Site Offsite
Site Offsite Site Offsite
Site Offsite Site Offsite
Site Offsite Site Offsite
Site Offsite
Roadway
0.24
0.02
Grassed Rightrof-ways
0.33
0.02
Driveway
0.65
Parking Id
0.02 1 1
1 1
Roof
1
0.02
0.65
Sidewalk (Includes Patios)
Lawn
1.94 1 0.22
1.57 0.22
Managed pervious (Open Space)
Woods (on lots)
2.71
0.59
1.10
0.35
Land Taken up by BMP
I0.31
0.04
JURISDICTIONAL LANDS
Site Offsite
Site Offsite Site Offsite
Site Offsite Site Offsite
Site Offsite Site Offsite
Site Offsite
Natural wetland
Riparian buffer (Zone 1 only)
Open water
Totals (Ac)=
0.00 0.00
4.69 0.22 1
4.85 r..22 0.00 T 0.00
0.43 0.00
SITE FLOW
PRE -DEVELOPMENT T,
POST -DEVELOPMENT Tc
Sheet Flow
Length (ft)=
100.00
100.00
Slope (tuft)=
0.03
0.03
Surface Cover:
Woods
Grass
-value=
0.40
0.240
Tr(Ii
0.29
0.19
Shallow FI
Length (ft)=
257.00
134.00
Slope (tuft)=
0.14
0.04
Surface Cover:
Unpaved
Unpaved
Average Velocity (tusac)=
6.04
3.23
T, (hs)-
0.01
0.01
Channel Flow 1
Length (ft)-
106.70
425.00
Slope (tuft)=
0.02
0.07
Cross Sectional Flow Area (ft')=
8.60
8.60
Wetted Perimeter (ft)=
14.28
14.26
Channel Lining:
Weeds
Grass
-value=
0.04
0.035
Hydraulic Radius (ft)=
0.60
0.60
Average Velocity (tusac)=
3.76
8.04
Tr(Ii
0.01
0.01
To(hrs)=
0.30
0.22
RESULTS
PRE -DEVELOPMENT
POST -DEVELOPMENT
She Impervious Surface Area (Ac) =
0.04
1.56
Lot Impervious Surface Area (Ac) =
0.02
1.30
1 -year, 24-hour storm (Peak Flow)
Volume of runoff (ft) =
6,886
21,680
Volume change (ft) =
14,794
Runoff (inches) = W=
0.3447
1.0859
Peak Discharge (cfs)= Q=
1.2469
6.3817
Composite Curve Number IDA)=
60
73
Composite Curve Number (Site only)=
60
73
DISCONNECTED IMPERVIOUS - Credit given only to residential development
with drainage area with les. than 30% impervious
Percent Disconnected Impervious Credit (Residential Only) =
Disconnected impervious area (Ac) =
50%
0.78
Drainage Area CNeaN,ed=
70
She Only CN,dt,s_=
71
DAi Page 1

WAKE
COUNTY
N([ K r I14:.4KOI INA
DA SITE SUMMARY
STORMWATER PRE -POST CALCULATIONS
Wake County SW Hybrid Tool Version 2.2
Project Name: I Layhill Estates
SITE SUMMARY
DRAINAGE AREA SUMMARIES
DRAINAGE AREA:
DA1
DA2
DA3
DA4
DA5
DA6
Pre -Development (1 -year, 24-hour storm)
Runoff (in)=Q* =
0.345
Peak Flow (cfs)=QPost =
1.247
Post -Development (1 -year, 24-hour storm)
Proposed Impervious Surface (acre) =
1.56
Runoff (in)=Q* =
1.086
Peak Flow (cfs)=Qpost =
6.382
TARGET CURVE NUMBER (TCN) - Residential Only
SITE \SOIL COMPOSITION
HYDROLOGIC SOIL GROUP
Site Area
%
Target CN
A
0.00
0%
41
B
4.85
92%
62
C
0.00
0%
75
D
0.43
8%
80
Total Site Area (acres) =
5.28
Zoning =
R -40W
Target Curve Number (TCN) =
63
% Impervious =
30%
Post Development CNadjusted =
71
Required Volume to be Managed (TCN)= ft3 =
5,551
SITE NITROGEN AND PHOSPHORUS LOADING
Nitrogen and Phosphorus Targets (Based on Regulatory Watershed)
Target Nitrogen Load (Ib/ac/yr)=
3.6
Target Phosphorus Load (Falls and Jordan Lakes Only) (Ib/ac/yr)=
N/A
% N Loading Reduction Option for Expansions (Falls and Jordan Lakes Only) =
N/A
• Loading Reduction Nitrogen Target (Falls and Jordan Lakes Only) (Ib/ac/yr)=
N/A
• P Loading Reduction Option for Expansions (Falls and Jordan Lakes Only) =
N/A
% Loading Reduction Phosphorus Target (Falls and Jordan Lakes Only) (Ib/ac/yr)=
N/A
Pre Development Nitrogen and Phosphorus Load
Total Nitrogen (Ib/ac/yr)=
1.00
Total Phosphorus (Ib/ac/yr)=
N/A
Post Development Nitrogen and Phosphorus Load
Total Nitrogen (Ib/ac/yr)=
5.06
Total Phosphorus (Ib/ac/yr)=
N/A
SITE SUMMARY Page 1

WAKE
COUNTY
NORTH( A RUI INA
Project Name: 1 Layhill Estates
DRAINAGE AREA 1
BMP CALCULATIONS
Wake County SW Hybrid Tool Version 2.2
DRAINAGE AREA 1 - BMP DEVICES AND ADJUSTMENTS
DA1 Site Acreage=
5.28
DA1 Off -Site Acreage=
0.22
Total Required Storage Volume for Site
TCN Requirement (ft3)=
5,551
Will site use underground water harvesting?
Enter % volume reduction in
decimal form=
Note: Supporting information/details
should be submitted to demonstrate
water usage.
ENTER AREA TREATED BY BMP
Land Use (acres)
Sub-DA1(a)
(Ac)
Sub-DA1(b)
(Ac)
Sub-DA1(c)
(Ac)
Sub-DA1(d)
(Ac)
Sub-DA1(e)
(Ac)
Commercial
Site
Off-site
Site
Off-site
Site
Off-site
Site Off-site
Site Off-site
Parking lot
Roof
Open/Landscaped
I
I
I
I
I
Industrial
Site
Off-site
Site
Off-site
Site
Off-site
Site Off-site
Site Off-site
Parking lot
I
I
I
I
I
Roof
I
I
I
I
I
Open/Landscaped
Transportation
Site
Off-site
Site
Off-site
Site
Off-site
Site Off-site
Site Off-site
High Density (interstate, main)
High Density (Grassed Right-of-ways)
Low Density (secondary, feeder)
Low Density (Grassed Right-of-ways)
I
I
I
I
I
Rural
I
I
I
I
I
Rural (Grassed Right-of-ways)
Sidewalk
Misc. Pervious
Site
j Off-site
Site
j Off-site
Site
j Off-site
Site j Off-site
Site Off-site
Managed pervious
Unmanaged (pasture)
Woods (not on lots)
I
I
I
I
Residential
Site
Off-site
Site
Off-site
Site
Off-site
Site Off-site
Site Off-site
Roadway
0.26
I
I
I
I
Grassed Right-of-ways
0.35
I
I
I
I
I
Driveway
0.65
'
Parking lot
Roof
0.65
Sidewalk
Lawn
1.57
1 0.22
I
I
I
I
Managed pervious
I
I
I
I
I
Woods (on lots)
1.45
I
I
I
I
I
Land Taken up by BMP
JURISDICTIONAL LANDS
Site
Off-site
Site
Offsite
Site
Offsite
Site Offsite
Site Offsite
Natural wetland
Riparian buffer (Zone 1 only)
Totals (Ac)=1
5.28
1 0.22
1 0.00
1 0.00
1 0.00
1 0.00
1 0.00 1 0.00
0.00 1 0.00
Sub-DAII(a) BMP(s)
Device Name (As Shown on Plan)
Device Type
Water
Quality
Volume
(C.f.)
Inflow N
EMC
(mg/L)
Total
Inflow N
(Ib/ac/yr)
Inflow P
EMC
(mg/L)
Total
Inflow P
(Ib/ac/yr)
Outflow
N EMC
(mg/L)
Total
Outflow
ac/yr
(Ib/N
Outflow
p EMC
(mg/L)
Total
Outflow
yManaged
(lb/ac
Provided
Volume
(c.f.)
POND
Dry Detention Pond
6,095
1.31
5.10
0.29
1.13
1.21
4.71
0.21
0.81
P
10,613
I
I
-
Outflow Total Nitrogen (Ib/ac/yr)=
4.71
Outflow Total Phosphorus (Ib/ac/yr)=
0.81
DA1_BMPs Page 1

Wake County SW Hybrid Tool Version 2.2
Sub-DA1(b) BMP(s)
If Sub-DA1(b) is connected to upstream sub-basin(s), select all contributing sub-basin(s from
dropdown menus):
Device Name (As Shown on Plan)
Device Type
Water
Quality
Volume
(C.f.)
Inflow N
EMC
(mg/L)
Total
Inflow N
(Ib/ac/yr)
Inflow P
EMC
(mg/L)
Total
Inflow P
(Ib/ac/yr)
Outflow
N EMC
(mg/L)
Total
Outflow
N
(Ib/ac/yr)
Outflow
p EMC
(mg/L)
Total
Outflow
P
(Ib/ac/yr)
Provided
Volume
Managed
(c.f.)
Outflow Total Nitrogen (Ib/ac/yr)=
Outflow Total Phosphorus (Ib/ac/yr)=
Sub-DA1 (c) BMP(s)
If Sub-DA1(c) is connected to upstream sub-basin(s), select all contributing sub-basin(s):
Device Name (As Shown on Plan)
Device Type
Water
Quality
Volume
(c.f.)
Inflow N
EMC
(mg/L)
Total
Inflow N
(Ib/ac/yr)
Inflow P
EMC
(mg/L)
Total
Inflow P
(Ib/ac/yr)
Outflow
N EMC
(mg/L)
Total
Outflow
N
(Ib/ac/yr)
Outflow
p EMC
(mg/L)
Total
Outflow
P
(Ib/ac/yr)
Provided
Volume
Managed
(c.f.)
Outflow Total Nitrogen (Ib/ac/yr)=
Outflow Total Phosphorus (Ib/ac/yr)=
Sub-DA1 (d) BMP(s)
If Sub-DA1(d) is connected to upstream sub-basin(s), select all contributing sub-basin(s):
Device Name (As Shown on Plan) Device Type
Water
Quality
Volume
(C.f.)
Inflow N
EMC
(mg/L)
Total
Inflow N
(Ib/ac/yr)
Inflow P
EMC
(mg/L)
Total
Inflow P
(Ib/ac/yr)
Outflow
N EMC
(mg/L)
Total
Outflow
N
(Ib/ac/yr)
Outflow
p EMC
(mg/L)
Total
Outflow
P
(Ib/ac/yr)
Provided
Volume
Managed
(c.f.)
Outflow Total Nitrogen (Ib/ac/yr)=
Outflow Total Phosphorus (Ib/ac/yr)=
Sub-DA1 (e) BMP(s)
If Sub-DA1(e) is connected to upstream sub-basin(s), select all contributing sub-basin(s):
Device Name (As Shown on Plan)
Device Type
Water
Quality
Volume
(c.f.)
Inflow N
EMC
(mg/L)
Total
Inflow N
(Ib/ac/yr)
Inflow P
EMC
(mg/L)
Total
Inflow P
(Ib/ac/yr)
Outflow
N EMC
(mg/L)
Total
Outflow
N
(Ib/ac/yr)
Outflow
p EMC
(mg/L)
Total
Outflow
P
(Ib/ac/yr)
Provided
Volume
Managed
(c.f.)
Outflow Total Nitrogen (Ib/ac/yr)=
Outflow Total Phosphorus (Ib/ac/yr)=
DA1 BMP SUMMARY
Total Volume Treated (c.f.)=
10613
DA1 Outflow Total Nitrogen (Ib/ac/yr)=
4.71
DA1 Outflow Total Phosphorus (Ib/ac/yr)=
0.81
1 -year, 24-hour storm
Pre Development Peak Discharge (Cfs)= Qi -yea
1.25
Post BMP Peak Discharge (cfs)= Q1.year
0.47
DA1_BMPs Page 1

Wake County SW Hybrid Tool Version 2.2
Project Name: Layhill Estates
�V� DA SITE SUMMARY
AKI BMP CALCULATIONS
COUNTY
NORTH CAROLINA
BMP SUMMARY
DRAINAGE AREA SUMMARIES
DRAINAGE AREA:
DA1
DA2
I DA3
DA4
DA5
DA6
Post -Development (1 -year, 24-hour storm)
Peak Flow (CfS)=Qt_year=
6.38
Post -Development with BMPs (1 -year, 24-hour storm)
% Impervious=
30%
Volume Managed (CF)=
10,613
Post BMP Peak Discharge (cfs)= Qt -year=
0.47
Have Target Curve Number Requirements been met?
YES
Pre Development Nitrogen and Phosphorus Load
Total Nitrogen (Ib/ac/yr)=
1.00
Total Phosphorus (Ib/ac/yr)=
N/A
Post Development Nitrogen and Phosphorus Load
Total Nitrogen (Ib/ac/yr)=
5.06
Total Phosphorus (Ib/ac/yr)=
N/A
Post -BMP Nitrogen Loading
Outflow Total Nitrogen (Ib/ac/yr)=
4.71
Outflow Total Phosphorus (Ib/ac/yr)=
0.81
Has site met the Target?
NO
Has site met requirements for offsetting?
YES
BMP SUMMARY Page 1

Permit No
Please complete the yellow shaded items.
-A � o��F W ATF9oG
�A STORMWATER MANAGEMENT PERMIT APPLICATION FORM
NCDENI� 401 CERTIFICATION APPLICATION FORM o
DRY EXTENDED DETENTION BASIN SUPPLEMENT
This form must be filled out, printed and submitted.
The Required Items Checklist (Part 111) must be printed, filled out and submitted along with all the required information.
(to be provided by DWQ)
Project name
LAYHILL ESTATES
Contact person
Khaled A AI-Zoubi
Phone number
[phone]
Date
10/15/2018
Drainage area number
1
II. DESIGN INFORMATION
Site Characteristics
Drainage area
239,422.63
ft2
Impervious area
71,826.79
ft2
% Impervious
0.30
Design rainfall depth
2.50
in
Peak Flow Calculations
1 -yr, 24 -hr rainfall depth
0.30
in
Rational C, pre -development
0.20
(unitless)
Rational C, post -development
0.54
(unitless)
Rainfall intensity: 1 -yr, 24 -hr storm
3.00
in/hr
Pre -development 1 -yr, 24 -hr peak flow
8.93
ft3/sec
Post -development 1 -yr, 24 -hr peak flow
5.41
ft3/sec
Pre/Post 1 -yr, 24 -hr peak control
-3.52
ft3/sec
Storage Volume: Non -SA Waters
Minimum required volume
6,120.00
ft3
Provided volume
7,900.00
ft3
OK
Sediment storage volume provided
1,975.00
ft3
OK
Storage Volume: SA Waters
1.5" runoff volume
ft3
Pre -development 1 -yr, 24 -hr runoff volume
ft3
Post -development 1 -yr, 24 -hr runoff volume
ft3
Minimum required volume
ft3
Provided volume
ft3
Sediment storage volume provided
ft3
Basin Design Parameters
Drawdown time
2.20
days
OK
SHWT elevation
387.00
fmsl
Basin bottom elevation
389.00
fmsl
OK
Storage elevation
393.70
fmsl
Basin side slopes
3.0
:1
OK
Top elevation
395.00
fmsl
OK
Freeboard provided
1.08
ft
OK
Basin Bottom Dimensions
Basin length
113.30
ft
Basin width
41.10
ft
Length to width ratio
3.00
:1
OK
Additional Information
Total runoff volume captured by basin
6.86
ac -in
Forebay is not required
Forebay provided
N
(Y or N)
Is basin in a recorded drainage easement?
Y
(Y or N)
OK
Does basin capture all runoff at ultimate build -out?
Y
(Y or N)
OK
Is a sediment depth indicator included?
Y
(Y or N)
OK
Does the basin include a drain?
Y
(Y or N)
OK
PDF processed with CutePDF evaluation edition www.CutePDF.com

IC ENGINEERING
Project: Layhill Project No.:
Calculated By: JCO Date:10/8/2018
Dry Extended Detention Basin Design SCM #1
1) Impervious Area
Drainage Area to BMP
Runoff Volume:
Impervious Area
Acres
Offsite Impervious Area
0.00
Onsite Impervious Area
1.58
Total Impervious Area
1.58
389.00
221
Total Drainage Area To BMP
5.28
Percent Impervious Area
30%
2.A) 1.0 Inch Water Quality Runoff Volume Calculation (Required)
Using the runoff volume calculations in the "Simple Method" as described by Schueler (1987)
Rv = 0.05 + 0.009(1) Where: Rv = Runoff Coefficient, in/in
I = Percent Impervious
1= 30%
Rv = 0.319
1.0 inch Water Quality
Runoff Volume:
Runoff volume, S= Desi n rainfall
Rv (Drainage Area
Design Rainfall =
1.0 inch
Drainage Area =
5.28 acres
Storage Required =
6,120 cu. ft.
* Must have forebay if storage required is over 10 acre -inches (36,300 c.f.)
Detention Volume Required 6,120 cu ft
25% Additonal Sed. Storage 7,650 cu ft (Minimum volume required at bottom of spillway)
2.13) 1.0 Inch Water Quality Runoff Volume Calculation (Provided)
Contour Elevation
Contour
Area
Incremental
Volume
Accumulated
Volume
Stage, Z
sq ft
cu ft
cu ft
ft
389.00
221
0
0
0.00
393.00
2,686
5,815
5,815
4.00
393.70
3,272
2,085
7,900
394.00
3,513
1,018
8,918
5.00
395.00
4,362
3,937
12,855
6.00
*Green shading is water quality elevation; Maximum allowed depth of dry pond = 10 ft
Provided Volume of Dry Basin 8,918 cu ft (to bottom of spillway)
3) Size Water Quality Orifice for (2-5) Day Drawdown for 1" Runoff Volume

Q1.0" = CdA(2gh)1/2 (Orifice Equation; Cd=0.60 & h=h/3; Pg 3-13 BMP Manual)
4.70
Water Quality Stage (ft)
1.00
Orfice Diameter (inches)
1.55
Driving Head (h/3) to Centroid of Orifice (ft)
0.03
Q1.0" Drawdown Rate (cfs)
6,120
Water Quality Volume (VWQ)
VWQ/ Q1.0" x 86,400
Drawdown Time (days)
2.2
Drawdown Time (days) (2 - 5 days)
4) Dry Basin Elevations
Basin Elevations
Top of Basin
395.00 ft (Min 1 ft Freeboard)
Bottom of Spillway
394.00 ft (min. 1.0' Above Water Quality Stage)
Top of Control Structure
393.70 ft
Secondary Orifice Invert
389.00 ft
100 Year Stage
ft
10 Year Stage
ft
2 Year Stage
ft
Water Quality Sta a
393.70 ft (1.0" Runoff)
Bottom of Basin
389.00 ft
Water Quality Invert
393.70 ft (At Control Structure)
Discharge Invert
388.90 ft FES

IC ENGINEERING
Project: Layhill
Calculated By: JCO
Project No.:
Date: 10/8/2018
Anti-Bouyancy Calculations Control Structure #1
Dimensions of Control Structure
C.S. Info 0.D.0
Width (ft) 5.00
Length (ft) 5.00
Height (ft) 5.00
Wall Thickness (ft) 0.50
Footer Design
Footer Thickness (ft) 1.00
Footer Length (ft) 7.00
Footer Width (ft) 7.00
Top Slab Thickness (ft) NA
1. D. ft
Pipes
Diameter (ft)
# Pipes
4.00
#1
1.25
1
4.00
#2
0.08
2
Pipe 2 =
#3
0.00
0
laced Volume
V= L x W x (HT+Footer) = C.F.
Displaced Water = C.F. * 62.4 PCF = lbs
Add 15% Factor of Safety To Displaced Water
V = 150 C.F.
Disp. Water = 9,360 LBS
15% F.S. = 10,764 LBS
Weight of Structure (150 PCF for CMU)
Walls =
6,750
LBS
(add)
Footer =
7,350
LBS
(add)
Pipe 1 =
92
LBS
(minus)
Pipe 2 =
1
LBS
(minus)
Pipe 3 =
0
LBS
(minus)
Weir #1 =
1200
LBS
(minus)
Weir #2 =
0
LBS
(minus)
Structure Weight =
12,807
LBS
OK
Use 7.0 ft x 7.0 ft x 1.0. ft Footing
Weirs Area (L x H = ft2) # Weirs
#1 16.00 1
#2 0.00 0

Guide to Color Key: I User Input Data I Calculated Value
Designed By: JCO Date: 10/26/18
Checked By: KAZ Date:
Company: IC Engineering
Project Name: Layhill Estates
Project No.: S-16-15
Site Location (City/Town) Raleigh
Culvert Id. OUTLET
1. Determine Design Flow, +Q, Pipe Diameter, D,,,, and downstream Tailwater
Elevation, TW This procedure is valid for a ratio of 0.7 < TAT D,, _, �7. The
dimensions determined by this procedure are shown on Figure 8.06h, and as defined as
?. Select a median stone size, D50_
Median stone size, D50 (ft) 0.67 Figure 8.06h
=).=T=rinine tli,� l:Aiange pooh depth to pipe diaiiiet,�r -10.
D3 = - 3.75 log — log L4.35 DJ 1
D o 4
Design storm
2 -yr
Design discharge, Q (cfs)
19
Submerged pipe diameter, Do (ft)
1.3 Figure 8.06h
Tailwater elevation, TW (ft)
1.6 Figure 8.06h
Note:relative to outlet invert, + up
Ratio TW/Do
1.3
Is procedure valid?
TRUE
Distance from outlet invert to
natural bed elevation, - down, Z
0.5 Figure 8.06h
It�\
Acceleration due to gravity, g
(ft/s2)
32.2
?. Select a median stone size, D50_
Median stone size, D50 (ft) 0.67 Figure 8.06h
=).=T=rinine tli,� l:Aiange pooh depth to pipe diaiiiet,�r -10.
D3 = - 3.75 log — log L4.35 DJ 1
D o 4

Plunge pool depth/pipe diameter
ratio, Z2/Do -0.5
4. Determine the plunge pool width, W, to pipe diameter ratio.
W, = 3.0 - Z3
DO DO
Side slope of the plunge pool should be 2H:1V or flatter -
Plunge pool width /pipe diameter
ratio, Ws/Do 3.5
5. Determine the plunge pool length to pipe diameter ratio.
L<.10 - 1- Z�
=
DD D®.
Plunge pool length/pipe diameter
ratio, Ls/Do 10.7
6.Calculate �-alues for Z2, W, and L, by multiplying the ratios by D.20
r Z, W� L
l D0 D0 Do I D. = Z2, W- Ls
Plunge pool depth, Z2 (ft) -0.6 Figure 8.06h
Plunge pool width, Ws (ft) 4.4 Figure 8.06h
Plunge pool length, Ls (ft) 13.4 Figure 8.06h
Determine Z1.
Z1=Z,2-Z
Depth of plunge pool, Z1 (ft) -1.1 Figure 8.06h
8. Determine L, and Lb -
Lt = LS - 6Z1 (Z1 is negative down)
Lb = Ls + 4Z, (Z, is negative doom)
Length from outlet to downstream
end of plunge pool, Lt (ft) 20.1 Figure 8.06h
Bottom length of plunge pool, Lb
(ft) 11.0 Fiaure 8.06h

9. Determine the plunge pool top width, Wt, and the water surface top width
of tailwater, IV'Tl -
Wt = WS — 4Z2 (Z2 is negative dawn)
W-nv = W. + 4(TW — Z2) (Z2 is negatiVC down)
Top width of plunge pool, Wt (ft) 6.8 Fiaure 8.O6h
Top width of plunge pool at
tailwater elevation, WTW (ft) 13.1 Figure 8.O6h
`phis method -is valid for:.
Q2 > 0-5
gDO
z.
D -0]-25
J
Check #1 Check #2
Is method valid? Yes Yes

PDF processed with CutePDF evaluation edition www.CutePDF.com

Hydrograph Report
Hydraflow Hydrographs Extension for AutoCAD® Civil 3D® 2016 by Autodesk, Inc. v11
Hyd. No. 1
DITCH -2
Hydrograph type
= Rational
Storm frequency
= 10 yrs
Time interval
= 1 min
Drainage area
= 2.200 ac
Intensity
= 3.642 in/hr
OF Curve
= Raleigh.IDF
. Composite (Area/C) = [(1.990 x 0.20) + (0.100 x 0.20) + (0.110 x 0.95)] / 2.200
Q (cfs)
2.00
1.00
0.00 -V
0
Peak discharge
Time to peak
Hyd. volume
Runoff coeff.
Tc by FAA
Asc/Rec limb fact
DITCH -2
Hyd. No. 1 -- 10 Year
Thursday, 10 / 11 / 2018
= 1.923 cfs
= 31 min
= 3,577 cuft
= 0.24*
= 31.00 min
= 1/1
10 20 30 40 50 60
Hyd No. 1
PDF processed with CutePDF evaluation edition www.CutePDF.com
Q (cfs)
2.00
1.00
1 0.00
70
Time (min)

Channel Report
Hydraflow Express Extension
for Autodesk® AutoCAD® Civil 3D® by Autodesk, Inc.
DICTH 2
Trapezoidal
Bottom Width (ft)
= 1.00
Side Slopes (z:1)
= 5.00, 5.00
Total Depth (ft)
= 1.50
Invert Elev (ft)
= 394.00
Slope (%)
= 1.31
N -Value
= 0.240
Calculations
Compute by:
Known Q
Known Q (cfs)
= 1.92
Elev (ft) Section
396.00
395.50
395.00
394.50
394.00
393.50
2 4 6 8
Highlighted
Depth (ft)
Q (cfs)
Area (sqft)
Velocity (ft/s)
Wetted Perim (ft)
Crit Depth, Yc (ft)
Top Width (ft)
EGL (ft)
10 12 14
Reach (ft)
Thursday, Oct 18 2018
= 0.86
= 1.920
= 4.56
= 0.42
= 9.77
= 0.31
= 9.60
= 0.86
Depth (ft)
2.00
1.50
1.00
0.50
_n Fn
16 18 20 v VV

L
u
O
0
CD
O
O
CD
CL
n
c
CD
n
CD
W
c
v
O�
CD
Q
O
n
C
CD
n
Storm Sewer Tabulation
Page 1
Station
Len
(ft)
Drng Area
Rnoff
coeff
(C)
Area x C
Tc
Rain
(1)
(in/hr)
Total
flow
(cfs)
Cap
full
(cfs)
Vel
(ft/s)
Pipe
Invert Elev
HGL Elev
Grnd / Rim Elev
Line ID
Line
To
Line
Incr
(ac)
Total
(ac)
Incr
Total
Inlet
(min)
Syst
(min)
Size
(in)
Slope
N
Dn
(ft)
Up
(ft)
Dn
(ft)
Up
(ft)
Dn
(ft)
Up
(ft)
1
End
34.000
2.20
2.20
0.24
0.53
0.53
5.0
5.0
7.2
3.81
18.01
3.26
18
2.94
389.00
390.00
390.45
390.75
390.52
394.00
OUTFALL
Project File: STORM DT2.stm
Number of lines: 1
Run Date: 10/29/2018
NOTES:Intensity = 89.28 / (Inlet time + 15.70) ^ 0.83 ; Return period =Yrs. 10 ; c = cir e = ellip b = box
Storm Sewers v11.00

Hydraflow Storm Sewers Extension for Autodesk® AutoCAD® Civil 3D® Proj. file: STORM DT2.stm
Bev (ft)
3W00
3800
390.00
387.00
384.00
38100
Line 7 - OUTFALL
0 5 10 15 20 25 30 35 40
Sri "GL = 390-45-SWoudicall flew rani
39&00
393-00
390.00
387.00
384.00
38,_00
45
Reach (fk)
Storm Sewers

L
u
O
0
CD
O
O
CD
CL
n
C
CD
n
CD
W
C
v
O
CD
Q
O
n
C
CD
n
Storm Sewer Tabulation
Page 1
Station
Len
Drng Area
Rnoff
Area x C
Tc
Rain
Total
Cap
Vel
Pipe
Invert Elev
HGL Elev
Grnd / Rim Elev
Line ID
coeff
(1)
flow
full
Line
To
Incr
Total
Incr
Total
Inlet
Syst
Size
Slope
Dn
Up
Dn
Up
Dn
Up
Line
(ft)
(ac)
(ac)
(C)
(min)
(min)
(in/hr)
(cfs)
(cfs)
(ft/s)
(in)
N
(ft)
(ft)
(ft)
(ft)
(ft)
(ft)
1
End
26.204
0.31
0.59
0.58
0.18
0.36
5.0
5.8
7.0
2.49
9.77
3.04
15
2.29
397.00
397.60
398.18
398.23
398.94
400.00
p-2
2
1
49.115
0.28
0.28
0.63
0.18
0.18
5.0
5.0
7.2
1.27
3.45
2.25
15
0.29
397.61
397.75
398.23
398.31
400.00
400.00
Pipe -1
Project File: STORM rd.stm
Number of lines: 2
Run Date: 10/29/2018
NOTES:Intensity = 89.28 / (Inlet time + 15.70) ^ 0.83 ; Return period =Yrs. 10 ; c = cir e = ellip b = box
Storm Sewers v11.00

Storm Sewer Profile
Proj. file. STORM rd.stm
Elev. (ft)
O
O M
p W M N
o�W
cu E ;
rn (D S
J0
o W
B
Cn
S
OCDLO
AOMM
Lu WW
9;;
WEE
N
J O
O�
O
�M
o WW
B 9;
C/) WE
410.00
407.00
410.00
407.00
404.00
404.00
401.00
401.00
398.00
395.00
0
o
398.00
395.00
0 10
HGL
20
EGL
30
40 50 60 70 80
Reach (ft)
90 100
Storm Sewers

1S
BASIN 1A
7P
Dry Pond)
8R
(new Reach)
Subcat Reach Pon Link Routing Diagram for layhill pond
Prepared by HydroCAD SAMPLER 1-800-927-7246 www.hydrocad.net, Printed 10/9/2018
HydroCADO 10.00-20 Sampler s/n S23976 © 2017 HydroCAD Software Solutions LLC

LAYH I LL
layhill pond Type 1124 -hr 1 -yr Rainfall=2.86"
Prepared by HydroCAD SAMPLER 1-800-927-7246 www.hydrocad.net Printed 10/9/2018
HydroCAD® 10.00-20 Sampler s/n S23976 @2017 HydroCAD Software Solutions LLC Page 2
This report was prepared with the free HydroCAD SAMPLER, which is licensed for evaluation and
educational use ONLY. For actual design or modeling applications you MUST use a full version of
HydroCAD which may be purchased at www.hydrocad.net. Full programs also include complete technical
support,training materials, and additional features which are essential for actual design work.
Summary for Subcatchment 1S: BASIN 1 A
Runoff = 5.28 cfs @ 12.07 hrs, Volume= 0.354 af, Depth= 0.77"
Runoff by SCS TR -20 method, UH=SCS, Weighted -CN, Time Span= 0.00-30.00 hrs, dt= 0.05 hrs
Type II 24 -hr 1 -yr Rainfall=2.86"
Area (ac) CN Description
5.500 73 from WAKE SWT
5.500 100.00% Pervious Area
Tc Length Slope Velocity Capacity Description
(min) (feet) (ft/ft) (ft/sec) (cfs)
13.8 Direct Entry, Direct
U)
V
3 3
0
M
2
1
0
Subcatchment 1S: BASIN 1 A
Hydrograph
5.28 cfs
Type II 24 -hr
1 -yr Rainfall=2.86"
Runoff Area=5.500 ac
Runoff Volume=0.354 of
Runoff Depth=0.77"
Tc=13.8 min
CN=73
0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30
Time (hours)
— Runoff

LAYH I LL
layhill pond Type 1124 -hr 1 -yr Rainfall=2.86"
Prepared by HydroCAD SAMPLER 1-800-927-7246 www.hydrocad.net Printed 10/9/2018
HydroCAD® 10.00-20 Sampler s/n S23976 @2017 HydroCAD Software Solutions LLC Page 3
This report was prepared with the free HydroCAD SAMPLER, which is licensed for evaluation and
educational use ONLY. For actual design or modeling applications you MUST use a full version of
HydroCAD which may be purchased at www.hydrocad.net. Full programs also include complete technical
support,training materials, and additional features which are essential for actual design work.
Summary for Reach 8R: (new Reach)
Inflow Area = 5.500 ac, 0.00% Impervious, Inflow Depth > 0.45" for 1 -yr event
Inflow = 0.47 cfs @ 13.25 hrs, Volume= 0.204 of
Outflow = 0.47 cfs @ 13.27 hrs, Volume= 0.204 af, Atten= 0%, Lag= 1.3 min
Routing by Stor-Ind+Trans method, Time Span= 0.00-30.00 hrs, dt= 0.05 hrs
Max. Velocity= 0.83 fps, Min. Travel Time= 0.5 min
Avg. Velocity = 0.55 fps, Avg. Travel Time= 0.8 min
Peak Storage= 14 cf @ 13.25 hrs
Average Depth at Peak Storage= 0.30'
Bank -Full Depth= 2.10' Flow Area= 15.3 sf, Capacity= 39.80 cfs
1.00' x 2.10' deep channel, n= 0.240 Sheet flow over Dense Grass
Side Slope Z -value= 3.0'/' Top Width= 13.60'
Length= 25.0' Slope= 0.1600 '/'
Inlet Invert= 389.00', Outlet Invert= 385.00'

LAYH I LL
layhill pond Type 1124 -hr 1 -yr Rainfall=2.86"
Prepared by HydroCAD SAMPLER 1-800-927-7246 www.hydrocad.net Printed 10/9/2018
HydroCAD® 10.00-20 Sampler s/n S23976 © 2017 HydroCAD Software Solutions LLC Page 4
This report was prepared with the free HydroCAD SAMPLER, which is licensed for evaluation and
educational use ONLY. For actual design or modeling applications you MUST use a full version of
HydroCAD which may be purchased at www.hydrocad.net. Full programs also include complete technical
support,training materials, and additional features which are essential for actual design work.
3
0
FL
0.5
0.45
0.4
0.35
0.3
0.25
0.2
0.15
0.1
0.05
Reach 8R: (new Reach)
Hydrograph
n 47 cfs
F-
FA
/�1��'r�flolw�4rea#5 --00ac-
- LKVo.-Flom��.�I DePW=JL1
Max -Ve1=483-fps-
n70.240-
L=250'
' I S0.1 000"/'
Ca ac ity=W.80 cfs
0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30
Time (hours)
— Inflow
— Outflow
i
i i
i
i i
FA
/�1��'r�flolw�4rea#5 --00ac-
- LKVo.-Flom��.�I DePW=JL1
Max -Ve1=483-fps-
n70.240-
L=250'
' I S0.1 000"/'
Ca ac ity=W.80 cfs
0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30
Time (hours)
— Inflow
— Outflow

LAYH I LL
layhill pond Type 1124 -hr 1 -yr Rainfall=2.86"
Prepared by HydroCAD SAMPLER 1-800-927-7246 www.hydrocad.net Printed 10/9/2018
HydroCAD® 10.00-20 Sampler s/n S23976 @2017 HydroCAD Software Solutions LLC Page 5
This report was prepared with the free HydroCAD SAMPLER, which is licensed for evaluation and
educational use ONLY. For actual design or modeling applications you MUST use a full version of
HydroCAD which may be purchased at www.hydrocad.net. Full programs also include complete technical
support,training materials, and additional features which are essential for actual design work.
Summary for Pond 7P: Dry Pond)
Inflow Area =
5.500 ac,
0.00% Impervious,
Inflow Depth = 0.77" for 1 -yr event
Inflow =
5.28 cfs @
12.07 hrs, Volume=
0.354 of
Outflow =
0.47 cfs @
13.25 hrs, Volume=
0.204 af, Atten= 91 %, Lag= 70.5 min
Primary =
0.47 cfs @
13.25 hrs, Volume=
0.204 of
Routing by Stor-Ind method, Time Span= 0.00-30.00 hrs, dt= 0.05 hrs
Peak Elev= 393.74' @ 13.25 hrs Surf.Area= 3,304 sf Storage= 7,811 cf
Plug -Flow detention time= 361.6 min calculated for 0.204 of (58% of inflow)
Center -of -Mass det. time= 225.1 min ( 1,102.3 - 877.2 )
Volume Invert
Avail.Storage Storage Description
#1 389.00'
12,636 cf Custom Stage Data (Prismatic) Listed below (Recalc)
Elevation Surf.Area
Inc.Store Cum.Store
(feet)
(sq -ft)
(cubic -feet) (cubic -feet)
389.00
221
0 0
390.00
728
475 475
393.00
2,686
5,121 5,596
393.70
3,272
2,085 7,681
394.00
3,513
1,018 8,699
395.00
4,362
3,938 12,636
Device Routing
Invert
Outlet Devices
#1 Device 3
393.70'
16.0' long Sharp -Crested Rectangular Weir 0 End Contraction (s)
1.5' Crest Height
#2 Primary
389.00'
1.0" Vert. Orifice/Grate C= 0.600
#3 Primary
389.00'
15.0" Round Culvert
L= 30.0' RCP, groove end w/headwall, Ke= 0.200
Inlet/ Outlet Invert= 389.00'/ 388.80' S=0.0067'/' Cc= 0.900
n=0.012 Concrete pipe, finished, Flow Area= 1.23 sf
#4 Primary
394.00'
20.0' long x 5.0' breadth Broad -Crested Rectangular Weir
Head (feet) 0.20 0.40 0.60 0.80 1.00 1.20 1.40 1.60 1.80 2.00
2.50 3.00 3.50 4.00 4.50 5.00 5.50
Coef. (English) 2.34 2.50 2.70 2.68 2.68 2.66 2.65 2.65 2.65
2.65 2.67 2.66 2.68 2.70 2.74 2.79 2.88
Primary OutFlow Max=0.47 cfs @ 13.25 hrs HW=393.74' (Free Discharge)
2=Orifice/Grate (Orifice Controls 0.06 cfs @ 10.44 fps)
3=Culvert (Passes 0.41 cfs of 14.11 cfs potential flow)
't--1 =Sharp -Crested Rectangular Weir (Weir Controls 0.41 cfs @ 0.65 fps)
4=Broad-Crested Rectangular Weir ( Controls 0.00 cfs)

LAYH I LL
layhill pond Type 1124 -hr 1 -yr Rainfall=2.86"
Prepared by HydroCAD SAMPLER 1-800-927-7246 www.hydrocad.net Printed 10/9/2018
HydroCAD® 10.00-20 Sampler s/n S23976 @2017 HydroCAD Software Solutions LLC Page 6
This report was prepared with the free HydroCAD SAMPLER, which is licensed for evaluation and
educational use ONLY. For actual design or modeling applications you MUST use a full version of
HydroCAD which may be purchased at www.hydrocad.net. Full programs also include complete technical
support,training materials, and additional features which are essential for actual design work.
5
4
0
3
0
FL
2
1
0
0
Pond 7P: Dry Pond)
Hydrograph
2 4 6 8 10 12 14 16 18 20 22 24 26 28 30
Time (hours)
— Inflow
— Primary

LAYH I LL
layhill pond Type 11 24 -hr 2 -yr Rainfall=3.60"
Prepared by HydroCAD SAMPLER 1-800-927-7246 www.hydrocad.net Printed 10/9/2018
HydroCAD® 10.00-20 Sampler s/n S23976 © 2017 HydroCAD Software Solutions LLC Page 7
This report was prepared with the free HydroCAD SAMPLER, which is licensed for evaluation and
educational use ONLY. For actual design or modeling applications you MUST use a full version of
HydroCAD which may be purchased at www.hydrocad.net. Full programs also include complete technical
support,training materials, and additional features which are essential for actual design work.
Summary for Subcatchment 1 S: BASIN 1 A
Runoff = 8.93 cfs @ 12.07 hrs, Volume= 0.572 af, Depth= 1.25"
Runoff by SCS TR -20 method, UH=SCS, Weighted -CN, Time Span= 0.00-30.00 hrs, dt= 0.05 hrs
Type II 24 -hr 2 -yr Rainfall=3.60"
Area (ac) CN Description
5.500 73 from WAKE SWT
5.500 100.00% Pervious Area
Tc Length Slope Velocity Capacity Description
min) (feet) (ft/ft) (ft/sec) (cfs)
13.8 Direct Entry, Direct
n
►1
y 6
3 5
0
M 4
I
1
N
Subcatchment 1S: BASIN 1 A
Hydrograph
8.93 cfs
--i - - - - i- - - - - - - - i --- -� - -
- Type Ij 24 -,hr
21yr RairifallL3.60"
Runoff Area=5.500 ac
- - -� --'Rurioff'Vol%me-0.t72'al
- - - -� - - - -i +Runoff Depth=f25"
CN=73
----'--' -! -!--'--'--'--'--'--'--! -! -
0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30
Time (hours)
— Runoff

LAYH I LL
layhill pond Type 1124 -hr 2 -yr Rainfall=3.60"
Prepared by HydroCAD SAMPLER 1-800-927-7246 www.hydrocad.net Printed 10/9/2018
HydroCAD® 10.00-20 Sampler s/n S23976 @2017 HydroCAD Software Solutions LLC Page 8
This report was prepared with the free HydroCAD SAMPLER, which is licensed for evaluation and
educational use ONLY. For actual design or modeling applications you MUST use a full version of
HydroCAD which may be purchased at www.hydrocad.net. Full programs also include complete technical
support,training materials, and additional features which are essential for actual design work.
Summary for Reach 8R: (new Reach)
Inflow Area = 5.500 ac, 0.00% Impervious, Inflow Depth > 0.92" for 2 -yr event
Inflow = 5.41 cfs @ 12.22 hrs, Volume= 0.421 of
Outflow = 4.96 cfs @ 12.24 hrs, Volume= 0.421 af, Atten= 8%, Lag= 1.4 min
Routing by Stor-Ind+Trans method, Time Span= 0.00-30.00 hrs, dt= 0.05 hrs
Max. Velocity= 1.54 fps, Min. Travel Time= 0.3 min
Avg. Velocity = 0.62 fps, Avg. Travel Time= 0.7 min
Peak Storage= 82 cf @ 12.24 hrs
Average Depth at Peak Storage= 0.89'
Bank -Full Depth= 2.10' Flow Area= 15.3 sf, Capacity= 39.80 cfs
1.00' x 2.10' deep channel, n= 0.240 Sheet flow over Dense Grass
Side Slope Z -value= 3.0'/' Top Width= 13.60'
Length= 25.0' Slope= 0.1600 '/'
Inlet Invert= 389.00', Outlet Invert= 385.00'

LAYH I LL
layhill pond Type 1124 -hr 2 -yr Rainfall=3.60"
Prepared by HydroCAD SAMPLER 1-800-927-7246 www.hydrocad.net Printed 10/9/2018
HydroCAD® 10.00-20 Sampler s/n S23976 @2017 HydroCAD Software Solutions LLC Page 9
This report was prepared with the free HydroCAD SAMPLER, which is licensed for evaluation and
educational use ONLY. For actual design or modeling applications you MUST use a full version of
HydroCAD which may be purchased at www.hydrocad.net. Full programs also include complete technical
support,training materials, and additional features which are essential for actual design work.
Reach 8R: (new Reach)
Hydrograph
5.41 cfs
4.96 cfs
Inflow Area=5.500 ac
Avg. Flow Depth=0.89'
Max Vel=1.54 fps -
n=0.240
L_25.0' -
S=0.1600 '/'
Capacity=39.80 cfs
5
4
-----------
U
0
LL
2
0
0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30
Time (hours)
— Inflow
— Outflow

LAYH I LL
layhill pond Type 1124 -hr 2 -yr Rainfall=3.60"
Prepared by HydroCAD SAMPLER 1-800-927-7246 www.hydrocad.net Printed 10/9/2018
HydroCAD® 10.00-20 Sampler s/n S23976 @2017 HydroCAD Software Solutions LLC Page 10
This report was prepared with the free HydroCAD SAMPLER, which is licensed for evaluation and
educational use ONLY. For actual design or modeling applications you MUST use a full version of
HydroCAD which may be purchased at www.hydrocad.net. Full programs also include complete technical
support,training materials, and additional features which are essential for actual design work.
Summary for Pond 7P: Dry Pond)
Inflow Area =
5.500 ac,
0.00% Impervious,
Inflow Depth = 1.25" for 2 -yr event
Inflow =
8.93 cfs @
12.07 hrs, Volume=
0.572 of
Outflow =
5.41 cfs @
12.22 hrs, Volume=
0.421 af, Atten= 39%, Lag= 9.2 min
Primary =
5.41 cfs @
12.22 hrs, Volume=
0.421 of
Routing by Stor-Ind method, Time Span= 0.00-30.00 hrs, dt= 0.05 hrs
Peak Elev= 393.92' @ 12.22 hrs Surf.Area= 3,450 sf Storage= 8,424 cf
Plug -Flow detention time= 213.6 min calculated for 0.421 of (74% of inflow)
Center -of -Mass det. time= 110.8 min ( 972.7 - 861.8 )
Volume Invert
Avail.Storage Storage Description
#1 389.00'
12,636 cf Custom Stage Data (Prismatic) Listed below (Recalc)
Elevation Surf.Area
Inc.Store Cum.Store
(feet)
(sq -ft)
(cubic -feet) (cubic -feet)
389.00
221
0 0
390.00
728
475 475
393.00
2,686
5,121 5,596
393.70
3,272
2,085 7,681
394.00
3,513
1,018 8,699
395.00
4,362
3,938 12,636
Device Routing
Invert
Outlet Devices
#1 Device 3
393.70'
16.0' long Sharp -Crested Rectangular Weir 0 End Contraction (s)
1.5' Crest Height
#2 Primary
389.00'
1.0" Vert. Orifice/Grate C= 0.600
#3 Primary
389.00'
15.0" Round Culvert
L= 30.0' RCP, groove end w/headwall, Ke= 0.200
Inlet/ Outlet Invert= 389.00'/ 388.80' S=0.0067'/' Cc= 0.900
n=0.012 Concrete pipe, finished, Flow Area= 1.23 sf
#4 Primary
394.00'
20.0' long x 5.0' breadth Broad -Crested Rectangular Weir
Head (feet) 0.20 0.40 0.60 0.80 1.00 1.20 1.40 1.60 1.80 2.00
2.50 3.00 3.50 4.00 4.50 5.00 5.50
Coef. (English) 2.34 2.50 2.70 2.68 2.68 2.66 2.65 2.65 2.65
2.65 2.67 2.66 2.68 2.70 2.74 2.79 2.88
Primary OutFlow Max=4.74 cfs @ 12.22 hrs HW=393.90' (Free Discharge)
2=Orifice/Grate (Orifice Controls 0.06 cfs @ 10.61 fps)
3=Culvert (Passes 4.69 cfs of 14.41 cfs potential flow)
't--1 =Sharp -Crested Rectangular Weir (Weir Controls 4.69 cfs @ 1.48 fps)
4=Broad-Crested Rectangular Weir ( Controls 0.00 cfs)

LAYH I LL
layhill pond Type 11 24 -hr 2 -yr Rainfall=3.60"
Prepared by HydroCAD SAMPLER 1-800-927-7246 www.hydrocad.net Printed 10/9/2018
HvdroCAD® 10.00-20 Sampler s/n S23976 © 2017 HvdroCAD Software Solutions LLC Paae 11
This report was prepared with the free HydroCAD SAMPLER, which is licensed for evaluation and
educational use ONLY. For actual design or modeling applications you MUST use a full version of
HydroCAD which may be purchased at www.hydrocad.net. Full programs also include complete technical
support,training materials, and additional features which are essential for actual design work.
Pond 7P: Dry Pond)
Hydrograph
8.93 cfs
9----
8
$ _ _ Inflow Area -5.500 ac
7 _ Oea;k E;lev-393.92'
5.41 cfs 4 St)raoe-�8,4�24'cf
p
T
2 - - - - - --
-
0
0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30
Time (hours)
Inflow
— Primary

LAYH I LL
layhill pond Type 1124 -hr 10 -yr Rainfall=5.28"
Prepared by HydroCAD SAMPLER 1-800-927-7246 www.hydrocad.net Printed 10/9/2018
HvdroCAD® 10.00-20 Sampler s/n S23976 © 2017 HvdroCAD Software Solutions LLC Paae 12
This report was prepared with the free HydroCAD SAMPLER, which is licensed for evaluation and
educational use ONLY. For actual design or modeling applications you MUST use a full version of
HydroCAD which may be purchased at www.hydrocad.net. Full programs also include complete technical
support,training materials, and additional features which are essential for actual design work.
Summary for Subcatchment 1 S: BASIN 1 A
Runoff = 18.38 cfs @ 12.06 hrs, Volume= 1.147 af, Depth= 2.50"
Runoff by SCS TR -20 method, UH=SCS, Weighted -CN, Time Span= 0.00-30.00 hrs, dt= 0.05 hrs
Type II 24 -hr 10 -yr Rainfall=5.28"
Area (ac) CN Description
5.500 73 from WAKE SWT
5.500 100.00% Pervious Area
Tc Length Slope Velocity Capacity Description
min) (feet) (ft/ft) (ft/sec) (cfs)
13.8 Direct Entry, Direct
2
1
1
1
Subcatchment 1S: BASIN 1 A
Hydrograph
18.38 cfs I -1
Type 1 247hr
- -' - - 1-TO�yr Rainfall? -5.2'8"-
- - - - --Fhmoff Area=5.500-ac
'-Ru*f Vo� me=1-'147' ef
I I LRunoff Depti,-2.5Q'
+Tc+13"brain
CN -73
-I- - I- - r - r - r - 7 - 7 - -I
i i I I I
Ili i i i iI
I i i I I
0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30
Time (hours)
— Runoff
L
-1
I
I--7----,-
i
Type 1 247hr
- -' - - 1-TO�yr Rainfall? -5.2'8"-
- - - - --Fhmoff Area=5.500-ac
'-Ru*f Vo� me=1-'147' ef
I I LRunoff Depti,-2.5Q'
+Tc+13"brain
CN -73
-I- - I- - r - r - r - 7 - 7 - -I
i i I I I
Ili i i i iI
I i i I I
0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30
Time (hours)
— Runoff

LAYH I LL
layhill pond Type 1124 -hr 10 -yr Rainfall=5.28"
Prepared by HydroCAD SAMPLER 1-800-927-7246 www.hydrocad.net Printed 10/9/2018
HydroCAD® 10.00-20 Sampler s/n S23976 @2017 HydroCAD Software Solutions LLC Page 13
This report was prepared with the free HydroCAD SAMPLER, which is licensed for evaluation and
educational use ONLY. For actual design or modeling applications you MUST use a full version of
HydroCAD which may be purchased at www.hydrocad.net. Full programs also include complete technical
support,training materials, and additional features which are essential for actual design work.
Summary for Reach 8R: (new Reach)
Inflow Area = 5.500 ac, 0.00% Impervious, Inflow Depth > 2.17" for 10 -yr event
Inflow = 18.97 cfs @ 12.07 hrs, Volume= 0.996 of
Outflow = 18.98 cfs @ 12.07 hrs, Volume= 0.996 af, Atten= 0%, Lag= 0.0 min
Routing by Stor-Ind+Trans method, Time Span= 0.00-30.00 hrs, dt= 0.05 hrs
Max. Velocity= 2.14 fps, Min. Travel Time= 0.2 min
Avg. Velocity = 0.68 fps, Avg. Travel Time= 0.6 min
Peak Storage= 224 cf @ 12.07 hrs
Average Depth at Peak Storage= 1.58'
Bank -Full Depth= 2.10' Flow Area= 15.3 sf, Capacity= 39.80 cfs
1.00' x 2.10' deep channel, n= 0.240 Sheet flow over Dense Grass
Side Slope Z -value= 3.0'/' Top Width= 13.60'
Length= 25.0' Slope= 0.1600 '/'
Inlet Invert= 389.00', Outlet Invert= 385.00'

LAYH I LL
layhill pond Type 1124 -hr 10 -yr Rainfall=5.28"
Prepared by HydroCAD SAMPLER 1-800-927-7246 www.hydrocad.net Printed 10/9/2018
HvdroCAD® 10.00-20 Sampler s/n S23976 © 2017 HvdroCAD Software Solutions LLC Paae 14
This report was prepared with the free HydroCAD SAMPLER, which is licensed for evaluation and
educational use ONLY. For actual design or modeling applications you MUST use a full version of
HydroCAD which may be purchased at www.hydrocad.net. Full programs also include complete technical
support,training materials, and additional features which are essential for actual design work.
3
0
FL
2
1
1
1
1
1
Reach 8R: (new Reach)
Hydrograph
18 9R cfs
1 Inflow-Avec&=-5 50(Y ac -
low �De�#hr18'
--i 1 Max V-eF:L--211 4 Ips
I I I I I I I I
-n-_0-2W
-1
1 01
I r
J 1 1 S_-0.160017'
rapacity -9_80 cfs-
I I I I I I
- - 1- - F -
0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30
Time (hours)
— Inflow
— Outflow
I
I
I
I
_k -
I
L
I
4
I
4
T
T
I
L
I
T
I
T
L
L
L
L
L
I
I
I
I
T
1
I
_ T
i
I
_ T
I
I
_ T
1
1 Inflow-Avec&=-5 50(Y ac -
low �De�#hr18'
--i 1 Max V-eF:L--211 4 Ips
I I I I I I I I
-n-_0-2W
-1
1 01
I r
J 1 1 S_-0.160017'
rapacity -9_80 cfs-
I I I I I I
- - 1- - F -
0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30
Time (hours)
— Inflow
— Outflow

LAYH I LL
layhill pond Type 1124 -hr 10 -yr Rainfall=5.28"
Prepared by HydroCAD SAMPLER 1-800-927-7246 www.hydrocad.net Printed 10/9/2018
HydroCAD® 10.00-20 Sampler s/n S23976 @2017 HydroCAD Software Solutions LLC Page 15
This report was prepared with the free HydroCAD SAMPLER, which is licensed for evaluation and
educational use ONLY. For actual design or modeling applications you MUST use a full version of
HydroCAD which may be purchased at www.hydrocad.net. Full programs also include complete technical
support,training materials, and additional features which are essential for actual design work.
Summary for Pond 7P: Dry Pond)
Inflow Area =
5.500 ac, 0.00% Impervious, Inflow Depth = 2.50" for 10 -yr event
Inflow =
18.38 cfs @ 12.06 hrs, Volume= 1.147 of
Outflow =
18.97 cfs @ 12.07 hrs, Volume= 0.996 af, Atten= 0%, Lag= 0.7 min
Primary =
18.97 cfs @ 12.07 hrs, Volume= 0.996 of
Routing by Stor-Ind
method, Time Span= 0.00-30.00 hrs, dt= 0.05 hrs
Peak Elev= 394.18' @ 12.07 hrs Surf.Area= 3,665 sf Storage= 9,343 cf
Plug -Flow detention time= 111.0 min calculated for 0.995 of (87% of inflow)
Center -of -Mass det. time= 48.7 min ( 890.0 - 841.3 )
Volume Invert Avail.Storage Storage Description
#1 389.00' 12,636 cf Custom Stage Data (Prismatic) Listed below (Recalc)
Elevation
Surf.Area Inc.Store Cum.Store
(feet)
(sq -ft) (cubic -feet) (cubic -feet)
389.00
221 0 0
390.00
728 475 475
393.00
2,686 5,121 5,596
393.70
3,272 2,085 7,681
394.00
3,513 1,018 8,699
395.00
4,362 3,938 12,636
Device Routing
Invert Outlet Devices
#1 Device 3
393.70' 16.0' long Sharp -Crested Rectangular Weir 0 End Contraction (s)
1.5' Crest Height
#2 Primary
389.00' 1.0" Vert. Orifice/Grate C= 0.600
#3 Primary
389.00' 15.0" Round Culvert
L= 30.0' RCP, groove end w/headwall, Ke= 0.200
Inlet/ Outlet Invert= 389.00'/ 388.80' S=0.0067'/' Cc= 0.900
n=0.012 Concrete pipe, finished, Flow Area= 1.23 sf
#4 Primary
394.00' 20.0' long x 5.0' breadth Broad -Crested Rectangular Weir
Head (feet) 0.20 0.40 0.60 0.80 1.00 1.20 1.40 1.60 1.80 2.00
2.50 3.00 3.50 4.00 4.50 5.00 5.50
Coef. (English) 2.34 2.50 2.70 2.68 2.68 2.66 2.65 2.65 2.65
2.65 2.67 2.66 2.68 2.70 2.74 2.79 2.88
Primary OutFlow Max=18.01 cfs @ 12.07 hrs HW=394.16' (Free Discharge)
2=Orifice/Grate (Orifice Controls 0.06 cfs @ 10.90 fps)
3=Culvert (Barrel Controls 14.90 cfs @ 12.14 fps)
't--1 =Sharp -Crested Rectangular Weir (Passes 14.90 cfs of 17.04 cfs potential flow)
4=Broad-Crested Rectangular Weir (Weir Controls 3.05 cfs @ 0.94 fps)

LAYH I LL
layhill pond Type 1124 -hr 10 -yr Rainfall=5.28"
Prepared by HydroCAD SAMPLER 1-800-927-7246 www.hydrocad.net Printed 10/9/2018
HydroCAD® 10.00-20 Sampler s/n S23976 © 2017 HydroCAD Software Solutions LLC Paqe 16
This report was prepared with the free HydroCAD SAMPLER, which is licensed for evaluation and
educational use ONLY. For actual design or modeling applications you MUST use a full version of
HydroCAD which may be purchased at www.hydrocad.net. Full programs also include complete technical
support,training materials, and additional features which are essential for actual design work.
2
1
1
1
Cn
� 1
0 1
FL
Pond 7P: Dry Pond)
Hydrograph
18.97 cfs
I I I I
I I I I I
4-
I I I I
T r F T T
i i i i i
L L L L L
I I I I
- - - + - -
I I I I
_ F _ T _ T _ T
1 i i i i
0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30
Time (hours)
— Inflow
— Primary

LAYH I LL
layhill pond Type 1124 -hr 25 -yr Rainfall=5.97"
Prepared by HydroCAD SAMPLER 1-800-927-7246 www.hydrocad.net Printed 10/9/2018
HvdroCAD® 10.00-20 Sampler s/n S23976 © 2017 HvdroCAD Software Solutions LLC Paae 17
This report was prepared with the free HydroCAD SAMPLER, which is licensed for evaluation and
educational use ONLY. For actual design or modeling applications you MUST use a full version of
HydroCAD which may be purchased at www.hydrocad.net. Full programs also include complete technical
support,training materials, and additional features which are essential for actual design work.
Summary for Subcatchment 1 S: BASIN 1 A
Runoff = 22.54 cfs @ 12.06 hrs, Volume= 1.404 af, Depth= 3.06"
Runoff by SCS TR -20 method, UH=SCS, Weighted -CN, Time Span= 0.00-30.00 hrs, dt= 0.05 hrs
Type II 24 -hr 25 -yr Rainfall=5.97"
Area (ac) CN Description
5.500 73 from WAKE SWT
5.500 100.00% Pervious Area
Tc Length Slope Velocity Capacity Description
min) (feet) (ft/ft) (ft/sec) (cfs)
13.8 Direct Entry, Direct
Subcatchment 1S: BASIN 1 A
Hydrograph
22.54 cfs
LT
22
1
1
1
20
18
---�--�-
16
--' -
N
� �
14��
3 12
------'--'
0
,� 10
t-
fi
-t
8�
6
--
--,-
4
-
-�
2.
--,-
0=
"
I - , - Type 1 247hr
125 -yr Rairifall�5.9'7"
__ Runoff Area=5.500 ac
RuniofflVo ume=1.404' af
_Runoff Deptht3.06"
Ir fi T�=13 A r> In
-I- r - -
0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30
Time (hours)
— Runoff

LAYH I LL
layhill pond Type 1124 -hr 25 -yr Rainfall=5.97"
Prepared by HydroCAD SAMPLER 1-800-927-7246 www.hydrocad.net Printed 10/9/2018
HydroCAD® 10.00-20 Sampler s/n S23976 @2017 HydroCAD Software Solutions LLC Page 18
This report was prepared with the free HydroCAD SAMPLER, which is licensed for evaluation and
educational use ONLY. For actual design or modeling applications you MUST use a full version of
HydroCAD which may be purchased at www.hydrocad.net. Full programs also include complete technical
support,training materials, and additional features which are essential for actual design work.
Summary for Reach 8R: (new Reach)
Inflow Area = 5.500 ac, 0.00% Impervious, Inflow Depth > 2.74" for 25 -yr event
Inflow = 21.87 cfs @ 12.09 hrs, Volume= 1.254 of
Outflow = 22.18 cfs @ 12.10 hrs, Volume= 1.253 af, Atten= 0%, Lag= 0.4 min
Routing by Stor-Ind+Trans method, Time Span= 0.00-30.00 hrs, dt= 0.05 hrs
Max. Velocity= 2.25 fps, Min. Travel Time= 0.2 min
Avg. Velocity = 0.70 fps, Avg. Travel Time= 0.6 min
Peak Storage= 249 cf @ 12.09 hrs
Average Depth at Peak Storage= 1.66'
Bank -Full Depth= 2.10' Flow Area= 15.3 sf, Capacity= 39.80 cfs
1.00' x 2.10' deep channel, n= 0.240 Sheet flow over Dense Grass
Side Slope Z -value= 3.0'/' Top Width= 13.60'
Length= 25.0' Slope= 0.1600 '/'
Inlet Invert= 389.00', Outlet Invert= 385.00'

LAYH I LL
layhill pond Type 1124 -hr 25 -yr Rainfall=5.97"
Prepared by HydroCAD SAMPLER 1-800-927-7246 www.hydrocad.net Printed 10/9/2018
HydroCAD® 10.00-20 Sampler s/n S23976 © 2017 HydroCAD Software Solutions LLC Paqe 19
This report was prepared with the free HydroCAD SAMPLER, which is licensed for evaluation and
educational use ONLY. For actual design or modeling applications you MUST use a full version of
HydroCAD which may be purchased at www.hydrocad.net. Full programs also include complete technical
support,training materials, and additional features which are essential for actual design work.
Reach 8R: (new Reach)
Hydrograph
-- -- 22.18cfs 1 1 - - - -I - --
22
- r
- r
- r
- -r
20
1
11
1
1
I
I
18
rrrrr
�i6
-----!-!-!-
Cn
u14
rrL77
X12
-L
-L
-L
-1
-J -
p
1
1
1
1
1
i 10
-7
-r
-r
-T-7
L
L
L
1
1
8
1
1
6
- 7-
r-
r-
T-
7
4
- L-
L
- L
- L
- L-
2
I
I
I
I
I
T
I I I
1 Inflow Area=5.500 ac
Avo`FJ�Qw:Deoth L 66'
_Max -Vel -±2.25 #per
I I I I I I
1 1 1n 0.2w
J - J - -1 _ _ I _ _ I _ _ J-6- 5111!
I I I I Imo+ I T
1 apace y- . -O clfs
I I I I I I I I
0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30
Time (hours)
— Inflow
— Outflow

LAYH I LL
layhill pond Type 1124 -hr 25 -yr Rainfall=5.97"
Prepared by HydroCAD SAMPLER 1-800-927-7246 www.hydrocad.net Printed 10/9/2018
HydroCAD® 10.00-20 Sampler s/n S23976 @2017 HydroCAD Software Solutions LLC Page 20
This report was prepared with the free HydroCAD SAMPLER, which is licensed for evaluation and
educational use ONLY. For actual design or modeling applications you MUST use a full version of
HydroCAD which may be purchased at www.hydrocad.net. Full programs also include complete technical
support,training materials, and additional features which are essential for actual design work.
Summary for Pond 7P: Dry Pond)
Inflow Area = 5.500 ac, 0.00% Impervious, Inflow Depth = 3.06" for 25 -yr event
Inflow = 22.54 cfs @ 12.06 hrs, Volume= 1.404 of
Outflow = 21.87 cfs @ 12.09 hrs, Volume= 1.254 af, Atten= 3%, Lag= 1.8 min
Primary = 21.87 cfs @ 12.09 hrs, Volume= 1.254 of
Routing by Stor-Ind method, Time Span= 0.00-30.00 hrs, dt= 0.05 hrs
Peak Elev= 394.27' @ 12.09 hrs Surf.Area= 3,742 sf Storage= 9,676 cf
Plug -Flow detention time= 94.1 min calculated for 1.254 of (89% of inflow)
Center -of -Mass det. time= 40.1 min ( 875.6 - 835.5 )
Volume Invert Avail.Storage Storage Description
#1 389.00' 12,636 cf Custom Stage Data (Prismatic) Listed below (Recalc)
Elevation Surf.Area Inc.Store Cum.Store
(feet) (sq -ft) (cubic -feet) (cubic -feet)
389.00 221 0 0
390.00 728 475 475
393.00 2,686 5,121 5,596
393.70 3,272 2,085 7,681
394.00 3,513 1,018 8,699
395.00 4,362 3,938 12,636
Device Routing Invert Outlet Devices
#1 Device 3 393.70' 16.0' long Sharp -Crested Rectangular Weir 0 End Contraction (s)
1.5' Crest Height
#2 Primary 389.00' 1.0" Vert. Orifice/Grate C= 0.600
#3 Primary 389.00' 15.0" Round Culvert
L= 30.0' RCP, groove end w/headwall, Ke= 0.200
Inlet/ Outlet Invert= 389.00'/ 388.80' S=0.0067'/' Cc= 0.900
n=0.012 Concrete pipe, finished, Flow Area= 1.23 sf
#4 Primary 394.00' 20.0' long x 5.0' breadth Broad -Crested Rectangular Weir
Head (feet) 0.20 0.40 0.60 0.80 1.00 1.20 1.40 1.60 1.80 2.00
2.50 3.00 3.50 4.00 4.50 5.00 5.50
Coef. (English) 2.34 2.50 2.70 2.68 2.68 2.66 2.65 2.65 2.65
2.65 2.67 2.66 2.68 2.70 2.74 2.79 2.88
Primary OutFlow Max=21.51 cfs @ 12.09 hrs HW=394.26' (Free Discharge)
2=Orifice/Grate (Orifice Controls 0.06 cfs @ 11.00 fps)
3=Culvert (Barrel Controls 15.08 cfs @ 12.29 fps)
't1=Sharp-Crested Rectangular Weir (Passes 15.08 cfs of 22.99 cfs potential flow)
4=Broad-Crested Rectangular Weir (Weir Controls 6.37 cfs @ 1.22 fps)

LAYH I LL
layhill pond Type 1124 -hr 25 -yr Rainfall=5.97"
Prepared by HydroCAD SAMPLER 1-800-927-7246 www.hydrocad.net Printed 10/9/2018
HvdroCAD® 10.00-20 Sampler s/n S23976 © 2017 HvdroCAD Software Solutions LLC Paae 21
This report was prepared with the free HydroCAD SAMPLER, which is licensed for evaluation and
educational use ONLY. For actual design or modeling applications you MUST use a full version of
HydroCAD which may be purchased at www.hydrocad.net. Full programs also include complete technical
support,training materials, and additional features which are essential for actual design work.
Pond 7P: Dry Pond)
Hydrograph
24 21
22+4
20 - - - - - -
i
18 +++
.,16 -' - -' -'
-
Cn
14 --t- + -
+-
o i2
[L 10 1 t t -t-
8
6 1 T- T- 7-
4 1L _ L _ 1 _
2 +
87 cfs
-inflow, Area -5.500 ac
pe 'k ,Ley -394.27'-
- - - S"aoe_-X9,6,76 �cf
-
0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30
Time (hours)
Inflow
— Primary

LAYH I LL
layhill pond Type 1124 -hr 100 -yr Rainfall=8.00"
Prepared by HydroCAD SAMPLER 1-800-927-7246 www.hydrocad.net Printed 10/9/2018
HydroCAD® 10.00-20 Sampler s/n S23976 @2017 HydroCAD Software Solutions LLC Page 22
This report was prepared with the free HydroCAD SAMPLER, which is licensed for evaluation and
educational use ONLY. For actual design or modeling applications you MUST use a full version of
HydroCAD which may be purchased at www.hydrocad.net. Full programs also include complete technical
support,training materials, and additional features which are essential for actual design work.
Summary for Subcatchment 1S: BASIN 1 A
Runoff = 35.23 cfs @ 12.06 hrs, Volume= 2.205 af, Depth= 4.81"
Runoff by SCS TR -20 method, UH=SCS, Weighted -CN, Time Span= 0.00-30.00 hrs, dt= 0.05 hrs
Type II 24 -hr 100 -yr Rainfall=8.00"
Area (ac) CN Description
5.500 73 from WAKE SWT
5.500 100.00% Pervious Area
Tc Length Slope Velocity Capacity Description
(min) (feet) (ft/ft) (ft/sec) (cfs)
13.8 Direct Entry, Direct
35
-rrr
30
- L
-L
-
25
y
3 20
o
FL 15
Subcatchment 1S: BASIN 1 A
Hydrograph
35.23 cfs
Type II 24 -hr
100 -yr Rainfall=8.00"
Runoff Area=5.500 ac
Runoff Volume=2.205 of
Runoff Depth=4.81"
Tc=13.8 min
10
5rt
0
CN=73
0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30
Time (hours)
— Runoff

LAYH I LL
layhill pond Type 1124 -hr 100 -yr Rainfall=8.00"
Prepared by HydroCAD SAMPLER 1-800-927-7246 www.hydrocad.net Printed 10/9/2018
HydroCAD® 10.00-20 Sampler s/n S23976 @2017 HydroCAD Software Solutions LLC Page 23
This report was prepared with the free HydroCAD SAMPLER, which is licensed for evaluation and
educational use ONLY. For actual design or modeling applications you MUST use a full version of
HydroCAD which may be purchased at www.hydrocad.net. Full programs also include complete technical
support,training materials, and additional features which are essential for actual design work.
Summary for Reach 8R: (new Reach)
Inflow Area = 5.500 ac, 0.00% Impervious, Inflow Depth > 4.48" for 100 -yr event
Inflow = 34.77 cfs @ 12.07 hrs, Volume= 2.054 of
Outflow = 34.47 cfs @ 12.08 hrs, Volume= 2.054 af, Atten= 1 %, Lag= 0.3 min
Routing by Stor-Ind+Trans method, Time Span= 0.00-30.00 hrs, dt= 0.05 hrs
Max. Velocity= 2.50 fps, Min. Travel Time= 0.2 min
Avg. Velocity = 0.75 fps, Avg. Travel Time= 0.6 min
Peak Storage= 345 cf @ 12.08 hrs
Average Depth at Peak Storage= 1.99'
Bank -Full Depth= 2.10' Flow Area= 15.3 sf, Capacity= 39.80 cfs
1.00' x 2.10' deep channel, n= 0.240 Sheet flow over Dense Grass
Side Slope Z -value= 3.0'/' Top Width= 13.60'
Length= 25.0' Slope= 0.1600 '/'
Inlet Invert= 389.00', Outlet Invert= 385.00'

LAYH I LL
layhill pond Type 1124 -hr 100 -yr Rainfall=8.00"
Prepared by HydroCAD SAMPLER 1-800-927-7246 www.hydrocad.net Printed 10/9/2018
HydroCAD® 10.00-20 Sampler s/n S23976 @2017 HydroCAD Software Solutions LLC Page 24
This report was prepared with the free HydroCAD SAMPLER, which is licensed for evaluation and
educational use ONLY. For actual design or modeling applications you MUST use a full version of
HydroCAD which may be purchased at www.hydrocad.net. Full programs also include complete technical
support,training materials, and additional features which are essential for actual design work.
3
3
N 2
2
0
LL 1
1
Reach 8R: (new Reach)
Hydrograph
34.47 cfs
a
Inflow Area=5.500 ac
Avg. Flow Depth_1.99'-
Max Vel=2.50 fps
n=0.240
L=25.0'
S=0.1600 '/'-
Capacity=39.80 cfs
0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30
Time (hours)
— Inflow
— Outflow
j
-
�
4-
4
Inflow Area=5.500 ac
Avg. Flow Depth_1.99'-
Max Vel=2.50 fps
n=0.240
L=25.0'
S=0.1600 '/'-
Capacity=39.80 cfs
0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30
Time (hours)
— Inflow
— Outflow

LAYH I LL
layhill pond Type 1124 -hr 100 -yr Rainfall=8.00"
Prepared by HydroCAD SAMPLER 1-800-927-7246 www.hydrocad.net Printed 10/9/2018
HydroCAD® 10.00-20 Sampler s/n S23976 @2017 HydroCAD Software Solutions LLC Page 25
This report was prepared with the free HydroCAD SAMPLER, which is licensed for evaluation and
educational use ONLY. For actual design or modeling applications you MUST use a full version of
HydroCAD which may be purchased at www.hydrocad.net. Full programs also include complete technical
support,training materials, and additional features which are essential for actual design work.
Summary for Pond 7P: Dry Pond)
Inflow Area =
5.500 ac, 0.00% Impervious, Inflow Depth = 4.81" for 100 -yr event
Inflow =
35.23 cfs @ 12.06 hrs, Volume= 2.205 of
Outflow =
34.77 cfs @ 12.07 hrs, Volume= 2.054 af, Atten= 1 %, Lag= 1.1 min
Primary =
34.77 cfs @ 12.07 hrs, Volume= 2.054 of
Routing by Stor-Ind
method, Time Span= 0.00-30.00 hrs, dt= 0.05 hrs
Peak Elev= 394.51' @ 12.07 hrs Surf.Area= 3,949 sf Storage= 10,613 cf
Plug -Flow detention time= 65.0 min calculated for 2.050 of (93% of inflow)
Center -of -Mass det. time= 28.4 min ( 851.0 - 822.6 )
Volume Invert Avail.Storage Storage Description
#1 389.00' 12,636 cf Custom Stage Data (Prismatic) Listed below (Recalc)
Elevation
Surf.Area Inc.Store Cum.Store
(feet)
(sq -ft) (cubic -feet) (cubic -feet)
389.00
221 0 0
390.00
728 475 475
393.00
2,686 5,121 5,596
393.70
3,272 2,085 7,681
394.00
3,513 1,018 8,699
395.00
4,362 3,938 12,636
Device Routing
Invert Outlet Devices
#1 Device 3
393.70' 16.0' long Sharp -Crested Rectangular Weir 0 End Contraction (s)
1.5' Crest Height
#2 Primary
389.00' 1.0" Vert. Orifice/Grate C= 0.600
#3 Primary
389.00' 15.0" Round Culvert
L= 30.0' RCP, groove end w/headwall, Ke= 0.200
Inlet/ Outlet Invert= 389.00'/ 388.80' S=0.0067'/' Cc= 0.900
n=0.012 Concrete pipe, finished, Flow Area= 1.23 sf
#4 Primary
394.00' 20.0' long x 5.0' breadth Broad -Crested Rectangular Weir
Head (feet) 0.20 0.40 0.60 0.80 1.00 1.20 1.40 1.60 1.80 2.00
2.50 3.00 3.50 4.00 4.50 5.00 5.50
Coef. (English) 2.34 2.50 2.70 2.68 2.68 2.66 2.65 2.65 2.65
2.65 2.67 2.66 2.68 2.70 2.74 2.79 2.88
Primary OutFlow Max=33.94 cfs @ 12.07 hrs HW=394.50' (Free Discharge)
2=Orifice/Grate (Orifice Controls 0.06 cfs @ 11.25 fps)
3=Culvert (Barrel Controls 15.50 cfs @ 12.63 fps)
't1=Sharp-Crested Rectangular Weir (Passes 15.50 cfs of 39.87 cfs potential flow)
4=Broad-Crested Rectangular Weir (Weir Controls 18.37 cfs @ 1.84 fps)

LAYH I LL
layhill pond Type 1124 -hr 100 -yr Rainfall=8.00"
Prepared by HydroCAD SAMPLER 1-800-927-7246 www.hydrocad.net Printed 10/9/2018
HydroCAD® 10.00-20 Sampler s/n S23976 © 2017 HydroCAD Software Solutions LLC Paqe 26
This report was prepared with the free HydroCAD SAMPLER, which is licensed for evaluation and
educational use ONLY. For actual design or modeling applications you MUST use a full version of
HydroCAD which may be purchased at www.hydrocad.net. Full programs also include complete technical
support,training materials, and additional features which are essential for actual design work.
3
3
N 2
Cn
2
_o
F 1
1
Pond 7P: Dry Pond)
Hydrograph
34.77 cfs
Inflow, Area -5.500 ac
beak �rev�394,'-
- - - - - - -�#o-�agd---All0,61a cf-
�
I --,--,--
0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30
Time (hours)
Inflow
— Primary

IC ENGINEERING
Project: Layhill Project No.:
Calculated By: Date:
DRAINAGE DITCH DESIGN (VELOCITY CONSTRAINT)
DIVERSION SWALE
THIS WORKSHEET IS DESIGNED TO DETERMINE CHANNEL LINNING BASED ON
FLOW AND DITCH GEOMETRY (BASE WIDTH, SIDE SLOPE, CHANNEL SLOPE).
THIS PROGRAM DETERMINES DEPTH OF FLOW, VELOCITY AND TRACTIVE FORCE
ASSUMING N=0.03 FOR GRASS OR RIP RAP [N CAN BE VARIED IF DESIRED].
{VARY DEPTH UNTIL Z ACTUAL EQUALS Z REQUIRED; v & t WILL BE CORRECT;
SELECT APPROPRIATE LINNING BASED ON TRACTIVE FORCE)
WATERSHED DATA
AREA (A)= 0.80 (ACRES)
COEF.(C)= 0.50 (DIMENSIONLESS)
INTE.(I)= 7.22 (IN/HR)
FLOW (Q)= 2.9 cfs (DA #1 & DA #2)
KNOWN QUANTITIES;
LINE CHANNEL WITH 6 " RIP -RAP (ASSUME 6 " EVEN IF USING GRASS)
MANNING= 0.030 (DIMENSIONLESS)
SLOPE= 0.067 (FT/FT)
Z REQUID= 0.22 RATIO
SIDE (M)= 2 :1
VARIABLE QUANTITIES Ditch Width & Depth);
LIMIT Y= FT 6.4 INCHES
LIMIT B= FT
COMPUTE TRACTIVE FORCE SECTION 8.05 NCDEHNR MANUAL
T=YDS 3.5 #/SQFT
Y=WEIGHT OF WATER (62.4 #/CUFT)
D=DEPTH OF FLOW IN CHANNEL (FT)
S=SLOPE OF CHANNEL (FT/FT)
T= 2.2 #/SQFT
N. AMER GREEN
LINNING #/SF #/SF
JUTE NET 0.45
CURLED MAT 1.55 S75 1.55
CLASS A(4"@9"THK) 2.00 S150 1.75
CLASS B(8"@18"THK) 3.50 SC150 2.10
CLASS 1(12"@22"THK) 5.00 C350 3.20
CLASS 11(18"@30"THK) 7.50 P300 8.00
DETERMINE IF Z ACTUAL GREATER THAN Z REQUIRED;
NEW A= 0.56 SQUARE FEET
NEW P= 2.37 WETTED PERIMETER
NEW R= 0.24 HYDRAULIC RADIUS
Z ACTUAL= 0.22 MUST BE GREATER THAN Z REQUIRED= 0.22
NEW V= 4.92 fps
FOR V < 2 FPS - LINNING NOT REQ'D; USE GRASS
MINIMUM DESIGN GEOMETRY
LINER: CLASS B RIPF 3.50 #/SQFT > 2.2 #/SQFT
WIDTH
------ 2.12 ----- -----------------
D \ /
E /
P= 0.53 FT \ /
T (Y) \ /
H----- ---------------
0 FT
BASE (B)
Ditch = 1.00 FT DEEP X 0' WIDE V -BOTTOM DITCH
Freeboard = 0.47 FT (For 10 Year Storm)
Ditch Liner: CLASS B RIPRAP
PDF processed with CutePDF evaluation edition www.CutePDF.com

IC ENGINEERING
Project: Layhill Project No.:
Calculated By: Date:
DRAINAGE DITCH DESIGN (VELOCITY CONSTRAINT)
SWALE SW
THIS WORKSHEET IS DESIGNED TO DETERMINE CHANNEL LINNING BASED ON
FLOW AND DITCH GEOMETRY (BASE WIDTH, SIDE SLOPE, CHANNEL SLOPE).
THIS PROGRAM DETERMINES DEPTH OF FLOW, VELOCITY AND TRACTIVE FORCE
ASSUMING N=0.03 FOR GRASS OR RIP RAP [N CAN BE VARIED IF DESIRED].
(VARY DEPTH UNTIL Z ACTUAL EQUALS Z REQUIRED; v & t WILL BE CORRECT;
SELECT APPROPRIATE LINNING BASED ON TRACTIVE FORCE)
WATERSHED DATA
AREA (A)= 0.32 (ACRES)
COEF.(C)= 0.65 (DIMENSIONLESS)
INTE.(I)= 7.22 (IN/HR)
FLOW
Q = 1.5 cfs (DA #1 & DA #2)
KNOWN QUANTITIES;
LINE CHANNEL WITH 6 " RIP -RAP (ASSUME 6 " EVEN IF USING GRASS)
MANNING= 0.030 (DIMENSIONLESS)
SLOPE= 0.067 (FT/FT)
Z REQUID= 0.12 RATIO
SIDE (M)= 3 :1
VARIABLE QUANTITIES Ditch Width & Depth);
LIMIT Y= 0.36 FT 4.3 INCHES
LIMIT B= 0.00 FT
COMPUTE TRACTIVE FORCE (SECTION 8.05 NCDEHNR MANUAL)
T=YDS 3.5 #/SQFT
Y=WEIGHT OF WATER (62.4 #/CUFT)
D=DEPTH OF FLOW IN CHANNEL (FT)
S=SLOPE OF CHANNEL (FT/FT)
T= 1.5 #/SQFT
N. AMER GREEN
LINNING #/SF #/SF
JUTE NET 0.45
CURLED MAT 1.55 S75 1.55
CLASS A(4"@9"THK) 2.00 S150 1.75
CLASS B(8"@18"THK) 3.50 SC150 2.10
CLASS 1(12"@22"THK) 5.00 C350 3.20
CLASS II(18"@30"THK) 7.50 P300 8.00
DETERMINE IF Z ACTUAL GREATER THAN Z REQUIRED;
NEW A= 0.39 SQUARE FEET
NEW P= 2.28 WETTED PERIMETER
NEW R= 0.17 HYDRAULIC RADIUS
Z ACTUAL= 0.12 MUST BE GREATER THAN Z REQUIRED= 0.12
NEW V= 3.96 fps
FOR V < 2 FPS - LINNING NOT REQ'D; USE GRASS
MINIMUM DESIGN GEOMETRY
LINER: North American Green 1.75 #/SQFT> 1.5 #/SQFT
(S75) WIDTH
2.16 ----• ----------------
D \ /
E \ /
P= 0.36 FT \ /
T (Y)
H ----
0 FT
BASE (B)
Ditch = 1.00 FT DEEP X 0' WIDE V -BOTTOM DITCH
Freeboard = 0.64 FT (For 10 Year Storm)
Ditch Liner: NORTH AMERICAN GREEN (S75)

IC ENGINEERING
Project: Layhill Project No.:
Calculated By: Date:
DRAINAGE DITCH DESIGN (VELOCITY CONSTRAINT)
SWALE NE
THIS WORKSHEET IS DESIGNED TO DETERMINE CHANNEL LINNING BASED ON
FLOW AND DITCH GEOMETRY (BASE WIDTH, SIDE SLOPE, CHANNEL SLOPE).
THIS PROGRAM DETERMINES DEPTH OF FLOW, VELOCITY AND TRACTIVE FORCE
ASSUMING N=0.03 FOR GRASS OR RIP RAP [N CAN BE VARIED IF DESIRED].
{VARY DEPTH UNTIL Z ACTUAL EQUALS Z REQUIRED; v & t WILL BE CORRECT;
SELECT APPROPRIATE LINNING BASED ON TRACTIVE FORCE)
WATERSHED DATA
AREA (A)= 0.30 (ACRES)
COEF.(C)= 0.65 (DIMENSIONLESS)
INTE.(I)= 7.22 (IN/HR)
FLOW (Q)= 1.4 cfs (DA #1 & DA #2)
KNOWN QUANTITIES;
LINE CHANNEL WITH 6 " RIP -RAP (ASSUME 6 " EVEN IF USING GRASS)
MANNING= 0.030 (DIMENSIONLESS)
SLOPE= 0.071 (FT/FT)
Z REQUID= 0.11 RATIO
SIDE (M)= 3 :1
VARIABLE QUANTITIES Ditch Width & Depth);
LIMIT Y= FT 4.2 INCHES
LIMIT B= FT
COMPUTE TRACTIVE FORCE SECTION 8.05 NCDEHNR MANUAL
T=YDS 3.5 #/SQFT
Y=WEIGHT OF WATER (62.4 #/CUFT)
D=DEPTH OF FLOW IN CHANNEL (FT)
S=SLOPE OF CHANNEL (FT/FT)
T= 1.6 #/SQFT
N. AMER GREEN
LINNING #/SF #/SF
JUTE NET 0.45
CURLED MAT 1.55 S75 1.55
CLASS A(4"@9"THK) 2.00 S150 1.75
CLASS B(8"@18"THK) 3.50 SC150 2.10
CLASS 1(12"@22"THK) 5.00 C350 3.20
CLASS 11(18"@30"THK) 7.50 P300 8.00
DETERMINE IF Z ACTUAL GREATER THAN Z REQUIRED;
NEW A= 0.37 SQUARE FEET
NEW P= 2.21 WETTED PERIMETER
NEW R= 0.17 HYDRAULIC RADIUS
Z ACTUAL= 0.11 MUST BE GREATER THAN Z REQUIRED= 0.11
NEW V= 4.00 fps
FOR V < 2 FPS - LINNING NOT REQ'D; USE GRASS
MINIMUM DESIGN GEOMETRY
LINER: North American Green 1.75 #/SQFT > 1.6 #/SQFT
(S75) WIDTH
------------------ 2.1 ----- -----------------
D \ /
E \ /
P= 0.35 FT \ /
T (Y) \ /
H----- ---------------
0 FT
BASE (B)
Ditch = 1.00 FT DEEP X 0' WIDE V -BOTTOM DITCH
Freeboard = 0.65 FT (For 10 Year Storm)
Ditch Liner: NORTH AMERICAN GREEN (S75)

10111/2018
NORTH
AMERICAN
GREEN
CHANNEL ANALYSIS
> > > DITCH 2
ECMDS 6.0
Name
DITCH 2
Discharge
1.92
Peak Flow Period
0.25
Channel Slope
0.0076
Channel Bottom Width
1
Left Side Slope
3
Right Side Slope
3
Low Flow Liner
Retardence Class
C 6-12 in
Vegetation Type
Bunch Type
Vegetation Density
Good 75-95%
Soil Type
Sandy Loam
Unreinforced Vegetation
- Class C - Bunch Type - Good 75-95%
North American Green
5401 St. Wendel-Cynthiana Rd.
Poseyville, Indiana 47633
Tel. [phone]
> Fax [phone]
www.nagreen.com
ECMDS v6.0
Phase Reach Discharge Velocity Normal Mannings N Permissable Calculated Safety Remarks Staple
Depth Shear Stress Shear Stress Factor Pattern
Unreinforced Straight 1.92 cfs 0.39 ft/s 1.13 ft 0.24 4.2 lbs/ft2 0.54 lbs/ft2
Vegetation
Underlying Straight 1.92 cfs 0.39 ft/s 1.13 ft -- 0.04 lbs/ft2 0 lbs/ft2
Substrate
https://ecmds.com/project/l 37933/channel-analysis/1 51530/show
7.84 STABLE --
30.94 STABLE --
HE

1
Hydrograph Report
Hydraflow Hydrographs Extension for Autodesk® Civil 3D® 2019 by Autodesk, Inc. v12
Thursday, 01 / 24 / 2019
Hyd. No. 1
ST -1
Hydrograph type
= Rational
Peak discharge
= 5.153 cfs
Storm frequency
= 25 yrs
Time to peak
= 31 min
Time interval
= 1 min
Hyd. volume
= 9,585 cuft
Drainage area
= 2.640 ac
Runoff coeff.
= 0.46*
Intensity
= 4.244 in/hr
Tc by FAA
= 31.00 min
OF Curve
= Raleigh.IDF
Asc/Rec limb fact
= 1/1
. Composite (Area/C) = [(1.740 x 0.20) + (0.900 x 0.95)] / 2.640
Q (cfs)
6.00
5.00
4.00
3.00
2.00
1.00
0 00
ST -1
Hyd. No. 1 -- 25 Year
0 10 20 30 40 50 60 70 v vv
Hyd No. 1 Time (min)

2
FAA Formula Tc Worksheet
Tc = 1.8(1.1 - C) x Flow length"0.5 / Watercourse slope ^0.333 Hydraflow Hydrographs Extension for Autodesk® Civil 3D@2019 by Autodesk, Inc. v12
Hyd. No. 1
ST -1
Descrption
Flow length (ft) = 624.00
Watercourse slope (%) = 0.78
Runoff coefficient (C) = 0.46
Time of Conc. (min) = 31

3
Hydrograph Report
Hydraflow Hydrographs Extension for AutoCAD® Civil 3D® 2016 by Autodesk, Inc. v11
Sunday, 01 / 13 / 2019
Hyd. No. 2
ST -2
Hydrograph type
= Rational
Peak discharge
= 0.990 cfs
Storm frequency
= 25 yrs
Time to peak
= 11 min
Time interval
= 1 min
Hyd. volume
= 653 cuft
Drainage area
= 0.400 ac
Runoff coeff.
= 0.37*
Intensity
= 6.689 in/hr
Tc by FAA
= 11.00 min
OF Curve
= Raleigh.IDF
Asc/Rec limb fact
= 1/1
Composite (Area/C) = [(0.090 x 0.95) + (0.310 x 0.20)] / 0.400
0 2
Hyd No. 2
ST -2
Hyd. No. 2 -- 25 Year
Q (cfs)
1.00
0.90
0.80
0.70
0.60
0.50
0.40
0.30
0.20
0.10
0 00
4 6 8 10 12 14 16 18 20 22
Time (min)

4
FAA Formula Tc Worksheet
Tc = 1.8(1.1 - C) x Flow length"0.5 / Watercourse slope ^0.333 Hydraflow Hydrographs Extension for AutoCAD® Civil 3D® 2016 by Autodesk, Inc. v11
Hyd. No. 2
ST -2
Descrption
Flow length (ft) = 246.00
Watercourse slope (%) = 6.80
Runoff coefficient (C) = 0.37
Time of Conc. (min) = 11

5
Hydrograph Report
Hydraflow Hydrographs Extension for AutoCAD® Civil 3D® 2016 by Autodesk, Inc. v11
Sunday, 01 / 13 / 2019
Hyd. No. 3
ST -3
Hydrograph type
= Rational
Peak discharge
= 0.796 cfs
Storm frequency
= 25 yrs
Time to peak
= 11 min
Time interval
= 1 min
Hyd. volume
= 525 cuft
Drainage area
= 0.350 ac
Runoff coeff.
= 0.34*
Intensity
= 6.689 in/hr
Tc by FAA
= 11.00 min
OF Curve
= Raleigh.IDF
Asc/Rec limb fact
= 1/1
Composite (Area/C) = [(0.050 x 0.95) + (0.300 x 0.20)] / 0.350
Q (cfs)
1.00
0.90
0.80
0.70
0.60
0.50
0.40
0.30
0.20
OF
0.10
0 00
0 2
Hyd No. 3
ST -3
Hyd. No. 3 -- 25 Year
Q (cfs)
1.00
0.90
0.80
0.70
0.60
0.50
0.40
0.30
0.20
0.10
0 00
4 6 8 10 12 14 16 18 20 22
Time (min)

FAA Formula Tc Worksheet
Tc = 1.8(1.1 - C) x Flow length"0.5 / Watercourse slope ^0.333 Hydraflow Hydrographs Extension for AutoCAD® Civil 3D® 2016 by Autodesk, Inc. v11
Hyd. No. 3
ST -3
Descrption
Flow length (ft) = 226.00
Watercourse slope (%) = 6.50
Runoff coefficient (C) = 0.34
Time of Conc. (min) = 11

Required
*USE
Required
*USE
Al
Sediment Trap 1
Peak Inflow Q=CxlxA
C value 0.46
intensity (25 year)
4.24
Drainage area (ac)
2.64
Peak Inflow (cfs)
5.15
Surface Area A=435 sf
xg25
Peak inflow (Q10)
5.15 cfs
Surface Area
Calculation (A)=
66.93
2,240 sf
Basin Shape
Ensure flow length to basin width ratio is greater than 2:1
Calculated Ratio=
length (ft)=
66.93
width (ft)= 33.47
LxW =
2,240
used Ratio=
length (ft)=
75.00
width (ft)= 30.00
LxW =
2,250
Basin Volume
Basin Dimensions
Top of water storage
Bottom Surface
Required Volume
Storage
71 37
Disturbed area
1.07
for basins 3600cf
3,852
CF
(ac)
(ft^3)
per ac of disturbed
56.93 23.47 2,240
2.5
4,407
75.00 30.00
area=
3
5,250
Basin Dimensions
Top of water storage
Bottom Surface
Water storage
Storage
71 37
area (sf)
depth (ft)
volume
length (ft) width (ft)
length (ft) width (ft)
(ft^3)
66.93 33.47
56.93 23.47 2,240
2.5
4,407
75.00 30.00
65.00 20.00 2,250
3
5,250
Top of basin
Freeboard depth (ft)
Total
Depth (ft)
length (ft) width (ft)
71 37
1
3.5
77 32
1
3

Required
*USE
Sediment Trap 2
Peak Inflow Q=CxlxA
C value 0.37
intensity (25 year)
6.69
Drainage area (ac)
0.4
Peak Inflow (cfs)
0.99
Surface Area A=435 sf
xg25
Peak inflow (q10)=
0.99 cfs
Surface Area
Calculation (A)=
29.35
431 sf
Basin Shane
Ensure flow length to basin width ratio is greater than 2:1
Calculated Ratio=
length (ft)=
29.35
width (ft)= 14.67
LxW =
431
used Ratio=
length (ft)=
60.00
width (ft)= 22.00
LxW =
1,320
Basin Volume
Basin Dimensions
Top of water storage
Bottom Surface
Required Volume
length (ft) width (ft)
length (ft) width (ft) area (sf)
Disturbed area
0.4
for basins 3600cf
1,440
CF
(ac)
2.5 1,988
per ac of disturbed
area=
Basin Dimensions
Top of water storage
Bottom Surface
Water storage
volume
length (ft) width (ft)
length (ft) width (ft) area (sf)
depth (ft)
29.35 14.67
19.35 4.67 431
2.5 589
58.00 20.00
48.00 10.00 1,160
2.5 1,988
Top of basin Total
length (ft) width (ft) Freeboard depth (ft) Depth (ft)
Required 35 21 1.5 3
* USE 60 22 1.5 3
Of

Required
USE
Sediment Trap 3
Peak Inflow Q=CxlxA
C value 0.34
intensity (25 year)
6.69
Drainage area (ac)
0.35
Peak Inflow (cfs)
0.80
Surface Area A=435 sf
xg25
Peak inflow (q10)=
0.80 cfs
Surface Area
Calculation (A)=
26.32
346 sf
Basin Shape
Ensure flow length to basin width ratio is greater than 2:1
Calculated Ratio=
length (ft)=
26.32
width (ft)= 13.16
LxW =
346
used Ratio=
length (ft)=
60.00
width (ft)= 22.00
LxW =
1,320
Basin Volume
Basin Dimensions
Top of water storage Bottom Surface
Water storage
depth (ft)
Required Volume
length (ft) width (ft) length (ft) width (ft) area (sf)
26.32 13.16 16.32 3.16 346
Disturbed area
0.25
for basins 3600cf
900
CF
(ac)
per ac of disturbed
area=
Basin Dimensions
Top of water storage Bottom Surface
Water storage
depth (ft)
volume
length (ft) width (ft) length (ft) width (ft) area (sf)
26.32 13.16 16.32 3.16 346
2.5
435
58.00 20.00 48.00 10.00 1,160
2.5
1,988
Top of basin Freeboard depth (ft) Total
length (ft) width (ft) Depth (ft)
Required 32 19 1.5 3
• USE 60 22 1.5 3
Of