HomeMy WebLinkAboutSW5191001_SW Report_2020042022 Davie LLC
SEA, PLLC
Project Overview:
22 Davie LLC will consist of a 22,000 sf manufacturing site and warehouse located at 1217
Harold Andrews Rd approximately 1.1 miles northeast of the intersection of Old US 421 and
Harold Andrews Road in Chatham County, Siler City, NC. The project parcel is approximately
13.56 acres and is almost entirely wooded.
The soils on site are classified as Hydrologic Soil Group (HSG) D. The site does not lie within a
special flood hazard area per FIRM Panel 3710876200K. There is an intermittent stream located
on site, per USGS Topo maps that runs from southwest to northeast across the western portion of
the parcel. There are no jurisdictional wetlands on site. The entire site drains to an unnamed
tributary of Rocky River, surface water classification C, that is part of the Cape Fear River
Basin.
Stormwater Requirements:
This project must comply with stormwater rules set forth by the Town of Siler City, NC and
NCDEQ. The maximum built upon area for Siler City low-density is 7%, while NCDEQ has a
24% built upon area low-density limit. This project will have a proposed built upon area density
of 6.69%. This project will utilize the use of sheet flow and vegetated conveyances to transport
all stormwater runoff. Therefore, since the project falls below the BUA limits, this will be
classified a Low-Density Stormwater Project by both the Town of Siler City and NCDEQ. No
permanent primary SCM’s are provided as a part of this project.
A 100 ft buffer is required along all perennial streams and a 50 ft buffer is required along all
intermittent streams. This buffer has been provided and shown on applicable plan sheets,
however the distance from the project limits to the existing stream buffer is +/-115LF. There is
no proposed disturbance inside the stream buffer.
Stormwater Treatment:
As a low-density stormwater project, primary permanent stormwater control measures are not
required. Two permanent grass lines swales and the use of sheet flow will provide water quality
treatment. All areas in the project site must remain vegetated and properly maintained to ensure
that stormwater runoff does not create erosion control issues.
The project as proposed, meets all the stormwater requirements set forth by the Town of Siler
City and NCDEQ. Refer the to “Attachments” for more information.
22 Davie LLC
SEA, PLLC
Attachments:
- DA-1 Existing Site Area Map
- DA-2 Proposed Site Area Map
- DA-3 Driveway Pipe Drainage Area Map
- DA-4 Vegetated Swale Drainage Area Map
- USGS Topo Map
- NRCS Hardbound Soils Map
- Hydrologic Soils Group Map
- FIRM Panel 3710874200J
- Aerial
- Permanent Ditch Sizing Calculations
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WBASIC MACHINERY CO INC.DB/PG:828/270PB/PG:89/34PARCEL ID:66749PIN#:8762-01-48-0000ZONING: A-REX
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P WILLIAM F MILHOLENDB/PG:318 / 48PB/PG: 89 / 34PARCEL ID: 61149PIN #: 8762-01-49-5125ZONING: LIUS HWY 421DAVIS MARY FRANCES LIFE ESTATEDB/PG:977/136PARCEL ID: 13732PIN #: 876201483145N
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DRAWING LEGENDSheet22 DAVIE LLC
Summey Engineering Associates, PLLC
Engineering - Land Planning - Consulting
P.O. Box 968 - Asheboro, NC 27204
Ph: 336-328-0902 / Fx: 336-328-0922
Email: info@asheboro.com
NC Professional Engineering Firm License No. P-0336
EXISTING SITE AREA MAPDrawn by:Checked by:ZHGSEA Job No:Date:E-5885JAN. 2020DA-1HMSJCHATHAM COUNTY - SILER CITY - NORTH CAROLINA
1217 HAROLD ANDREWS RD
P:\E-5885 Milholen-basic machinery\DWG\Civil Site\Drainage - 22 Davie - 01-02-20.dwg, 1/13/2020 1:23:43 PM, Zach,_AutoCAD PDF (General Documentation).pc3
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WBASIC MACHINERY CO INC.DB/PG:828/270PB/PG:89/34PARCEL ID:66749PIN#:8762-01-48-0000ZONING: A-R9
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P WILLIAM F MILHOLENDB/PG:318 / 48PB/PG: 89 / 34PARCEL ID: 61149PIN #: 8762-01-49-5125ZONING: LIUS HWY 421DAVIS MARY FRANCES LIFE ESTATEDB/PG:977/136PARCEL ID: 13732PIN #: 876201483145N
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DRAWING LEGENDSheetSummey Engineering Associates, PLLC
Engineering - Land Planning - Consulting
P.O. Box 968 - Asheboro, NC 27204
Ph: 336-328-0902 / Fx: 336-328-0922
Email: info@asheboro.com
NC Professional Engineering Firm License No. P-0336
PROPOSED SITE AREA MAPDrawn by:Checked by:ZHGSEA Job No:Date:E-5885JAN. 2020DA-2HMSJCHATHAM COUNTY - SILER CITY - NORTH CAROLINA
22 DAVIE LLC
1217 HAROLD ANDREWS RD
P:\E-5885 Milholen-basic machinery\DWG\Civil Site\Drainage - 22 Davie - 01-02-20.dwg, 1/13/2020 1:23:45 PM, Zach,_AutoCAD PDF (General Documentation).pc3
Harold Andrews RdSR 1316 60' R/W 915" RCP NCDOT RIGHT OF WAYVAN
DRAWING LEGENDSheetSummey Engineering Associates, PLLC
Engineering - Land Planning - Consulting
P.O. Box 968 - Asheboro, NC 27204
Ph: 336-328-0902 / Fx: 336-328-0922
Email: info@asheboro.com
NC Professional Engineering Firm License No. P-0336
DRIVEWAY PIPE DRAINAGE AREA MAPDrawn by:Checked by:ZHGSEA Job No:Date:E-5885JAN. 2020DA-3HMSJCHATHAM COUNTY - SILER CITY - NORTH CAROLINA
22 DAVIE LLC
1217 HAROLD ANDREWS RD
P:\E-5885 Milholen-basic machinery\DWG\Civil Site\Drainage - 22 Davie - 01-02-20.dwg, 1/13/2020 1:23:50 PM, Zach,_AutoCAD PDF (General Documentation).pc3
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DRAWING LEGENDSheetSummey Engineering Associates, PLLC
Engineering - Land Planning - Consulting
P.O. Box 968 - Asheboro, NC 27204
Ph: 336-328-0902 / Fx: 336-328-0922
Email: info@asheboro.com
NC Professional Engineering Firm License No. P-0336
VEGETATED SWALE DRAINAGE AREA MAPDrawn by:Checked by:ZHGSEA Job No:Date:E-5885JAN. 2020DA-4HMSJCHATHAM COUNTY - SILER CITY - NORTH CAROLINA
22 DAVIE LLC
1217 HAROLD ANDREWS RD
P:\E-5885 Milholen-basic machinery\DWG\Civil Site\Drainage - 22 Davie - 01-02-20.dwg, 1/13/2020 1:23:55 PM, Zach,_AutoCAD PDF (General Documentation).pc3
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3971000mN
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3958000mN
71
37 38 39 40 41 42 43 44 4536 646 000mE
37 38 39 40 41 42 43 44 45636000mE 46
35.7500°
35.8750°
-79.5000°-79.3750°
35.8750°
35.7500°
-79.3750°-79.5000°
QUADRANGLE LOCATION
CRUTCHFIELD CROSSROADS QUADRANGLE
NORTH CAROLINA
7.5-MINUTE SERIES
CRUTCHFIELD CROSSROADS, NC
2019
Expressway Local Connector
ROAD CLASSIFICATION
Ramp 4WD
Secondary Hwy Local Road
Interstate Route State RouteUS Route
W
X
.
/H
U.S. DEPARTMENT OF THE INTERIOR
U.S. GEOLOGICAL SURVEY
This map was produced to conform with the
National Geospatial Program US Topo Product Standard, 2011.
A metadata file associated with this product is draft version 0.6.18
CONTOUR INTERVAL 10 FEET
NORTH AMERICAN VERTICAL DATUM OF 1988
SCALE 1:24 000
1000 500 0 METERS 1000 2000
21KILOMETERS00.51
1 0.5 0
MILES
1
1000 0 1000 2000 3000 4000 5000 6000 7000 8000 9000 10000
FEET
×
0°55´
16 MILS
8°50´
157 MILS
UTM GRID AND 2019 MAGNETIC NORTH
DECLINATION AT CENTER OF SHEET
PV
Grid Zone Designation
17S
U.S. National Grid
100,000 - m Square ID
NORTH
CAROLINA
1 Kimesville
8 Siler City NE
2 Snow Camp
3 Saxapahaw
4 Liberty
5 Silk Hope
6 Coleridge
7 Siler City
ADJOINING QUADRANGLES
2
6
4
1 3
7 8
5
Imagery.....................................................NAIP, May 2016 - November 2016
Roads......................................... U.S. Census Bureau, 2016
Names............................................................................GNIS, 1980
Hydrography...............................National Hydrography Dataset, 1899 - 2018
Contours............................................National Elevation Dataset, 2008
Boundaries..............Multiple sources; see metadata file 2017 - 2018
Wetlands.................FWS National Wetlands Inventory 1983
North American Datum of 1983 (NAD83)
World Geodetic System of 1984 (WGS84). Projection and
1 000-meter grid:Universal Transverse Mercator, Zone 17S
Produced by the United States Geological Survey
This map is not a legal document. Boundaries may be
generalized for this map scale. Private lands within government
reservations may not be shown. Obtain permission before
entering private lands.
PROJECT SITE
PROJECT SITE
FLOOD HAZARD INFORMATIO N
SPECIAL FLOOD
HAZARD AR EAS
OTHER AREAS OF
FLOOD HAZARD
OTHER
AREAS
GENERAL
STRUCTURES
Without Base Flood Elevation (BFE)
With BFE or Depth
Regulatory Floodway
Areas Determined to be Outside the
0.2% Annual Chance Floodplain
Non-accredited Levee, Dike, or Floodwall
Zone A,V, A99
Zone AE, AO, AH, VE, AR
Zone X
HTTP://FRIS.NC.GOV/FRIS
THE INFORMATION DEPICTED ON THIS MAP AND SUPPORTING
DOCUMENTATION ARE ALSO AVAILABLE IN DIGITAL FORMAT AT
NORTH CAROLIN A FLOODPLAIN MAPPING PROGRAM
FLOOD INSURANCE RATE MAP
NORTH CAROLIN A
PANEL
SEE FIS REPORT FOR ZONE DESCRIPTIONS AND INDEX MAP
Cross Sections with 1% Annual Chance
Water Surface Elevation (BFE)
Coastal Transect
OTHER
FEATURES
Profile Baseline
Hydrographic Feature
Limit of Study
Limit of Moderate Wave Action (LiMWA)
Jurisdiction Boundary
Accredited or Provisionally Accredited
Levee, Dike, or Floodwall
Coastal Transect Baseline
SCA LE
1 inch = 500 feet
Map Projection:
North Carolina State Plane Projection Feet (Zone 3200)
Datum: NAD 1983 (Horizontal), NAVD 1988 (Vertical)
PANEL LOCATOR
LOGO LOGO
NOTES TO USERS
For information and questions about this map, available products associated with this FIRM including
historic versions of this FIRM, how to order products or the National Flood Insurance Program in general,
please call the FEMA Map Information eXchange at 1-877-FEMA-MAP (1-877-336-2627) or visit the FEMA Map
Service Center website at http://msc.fema.gov. An accompanying Flood Insurance Study report, Letter of Map
Revision (LOMR) or Letter of Map Amendment (LOMA) revising portions of this panel, and digital versions of this
FIRM may be available. Visit the North Carolina Floodplain Mapping Program website at http://www.ncfloodmaps.com,
or contact the FEMA Map Service Center.
Communities annexing land on adjacent FIRM panels must obtain a current copy of the adjacent panel as well as
the current FIRM Index. These may be ordered directly from the Map Service Center at the number listed above.
For community and countywide map dates refer to the Flood Insurance Study report for this jurisdiction.
To determine if flood insurance is available in the community, contact your Insurance agent or call the National
Flood Insurance Program at 1-800-638-6620.
Flood Insurance Study (FIS) means an examination, evaluation, and determination of flood hazards, corresponding
water surface elevations, flood hazard risk zones, and other flood data in a community issued by the North Carolina
Floodplain Mapping Program (NCFMP). The Flood Insurance Study (FIS) is comprised of the following products
used together: the Digital Flood Hazard Database, the Water Surface Elevation Rasters, the digitally derived,
autogenerated Flood Insurance Rate Map and the Flood Insurance Survey Report. A Flood Insurance Survey is a
compilation and presentation of flood risk data for specific watercourses, lakes, and coastal flood hazard areas within
a community. This report contains detailed flood elevation data, data tables and FIRM indices. When a flood study is
completed for the NFIP, the digital information, reports and maps are assembled into an FIS. Information shown on
this FIRM is provided in digital format by the NCFMP. Base map information shown on this FIRM was provided in
digital format by the NCFMP. The source of this information can be determined from the metadata available in the
digital FLOOD database and in the Technical Support Data Notebook (TSDN).
ACCREDITED LEVEE NOTES TO USERS: If an accredited levee note appears on this panel check with your local
community to obtain more information, such as the estimated level of protection provided (which may exceed the
1-percent-annual-chance level) and Emergency Action Plan, on the levee system(s) shown as providing protection.
To mitigate flood risk in residual risk areas, property owners and residents are encouraged to consider flood
insurance and floodproofing or other protective measures. For more information on flood insurance, interested
parties should visit the FEMA Website at http://www.fema.gov/business/nfip/index.shtm.
PROVISIONALLY ACCREDITED LEVEE NOTES TO USERS: If a Provisionally Accredited Levee (PAL) note
appears on this panel, check with your local community to obtain more information, such as the estimated level of
protection provided (which may exceed the 1-percent-annual-chance level) and Emergency Action Plan, on the
levee system(s) shown as providing protection. To maintain accreditation, the levee owner or community is
required to submit the data and documentation necessary to comply with Section 65.10 of the NFIP regulations.
If the community or owner does not provide the necessary data and documentation or if the data and documentation
provided indicates the levee system does not comply with Section 65.10 requirements, FEMA will revise the flood
hazard and risk information for this area to reflect de-accreditation of the levee system. To mitigate flood risk in
residual risk areas, property owners and residents are encouraged to consider flood insurance and floodproofing
or other protective measures. For more information on flood insurance, interested parties should visit the FEMA
Website at http://www.fema.gov/business/nfip/index.shtm.
LIMIT OF MODERATE WAVE ACTION NOTES TO USERS: For some coastal flooding zones the AE Zone
category has been divided by a Limit of Moderate Wave Action (LiMWA). The LiMWA represents the approximate
landward limit of the 1.5-foot breaking wave. The effects of wave hazards between the VE Zone and the LiMWA
(or between the shoreline and the LiMWA for areas where VE Zones are not identified) will be similar to, but less
severe than those in the VE Zone.
COASTAL BARRIER RESOURCES SYSTEM (CBRS) NOTE
This map may include approximate boundaries of the CBRS for informational purposes only. Flood insurance is not
available within CBRS areas for structures that are newly built or substantially improved on or after the date(s)
indicated on the map. For more information see http://www.fws.gov/cbra, the FIS Report, or call the U.S. Fish
and Wildlife Service Customer Service Center at 1-800-344-WILD.
CBRS Area Other wise Protected Area
Channel, Culvert, or Storm Sewer
0.2% Annual Chance Flood Hazard, Areas
of 1% Annual Chance Flood with Average
Depth Less Than One Foot or With Drainage
Areas of Less Than One Square Mile
Future Conditions 1% Annual
Chance Flood Hazard
Area with Reduced Flood Risk due to Levee
See Notes
Zone X
Zone X
Zone X
8762
1:6,000
%,
012 18.2
!(
8
1860000 FEET
720000 FEET
1860000 FEET
730000 FEET
1870000 FEET
730000 FEET
1870000 FEET
720000 FEET
This digital Flood Insurance Rate Map (FIRM) was produced through a unique
cooperative partnership between the State of North Carolina and the Federal
Emergency Management Agency (FEMA). The State of North Carolina has
implemented a long term approach to floodplain management to decrease the
costs associated with flooding. This is demonstrated by the State's commitment
to map flood hazard areas at the local level. As a part of this effort, the State of
North Carolina has joined in a Cooperating Technical State agreement with
FEMA to produce and maintain this digital FIRM.
NATIONAL FLOOD INSURANCE PROGRAM
£¤
421
£¤
64
£¤
421
£¤
64
£¤
421
Loves
Creek
Tributary 3
TOWN OF
SILER CITY
370058
TOWN OF
SILER CITY
370058
TOWN OF
SILER CITY
370058
TOWN OF
SILER CITY
370058
TOWN OF SILER
CITY ETJ
370058
TOWN OF SILER
CITY ETJ
370058
TOWN OF
SILER CITY ETJ
370058
TOWN OF
SILER CITY ETJ
370058
ZONE AE
ZONE AE
ZONE AE
ZONE AE
i
068
i
158
i
062
i
074
i
078
i
071
i
144
i
153
i
124
i
084
i
140
i
114
i
099
i
082
i
108
i
120
i
064
i
166
i
095
i
104
i
059
i
089
i
111
i
082
i
048
i
060
i
072
i
129
i
149
i
135
Z3359Z
EZ1258EZ1259
EZ1260
EZ1261EZ1265
EZ2847
79°26'30"W
79°26'30"W
79°27'0"W
79°27'0"W
79°27'30"W
79°27'30"W
79°28'0"W
79°28'0"W
35°45'0"N
35°45'0"N
35°44'30"N
35°44'30"N
35°44'0"N
35°44'0"N
Guilford
Alamance
Orange Durham
Wake
Randolph
Chatham
Moore
Lee
Harnett
8624 8644 8664
8685 8695 9605 9615 9625 9635 9645 9685 9695
0604 0624
8746 8766
9727 9737
9746
9767 0717 0727
8786 8796 9706 9716 9726 9736 9766 9776 9786 9796 0706 0716 0726
8724 8744 8764 8784 9704
9725 9735 9745 9755 9765 9775
9784 0704
0725
9724 9734 9744 9754 9764 9774 0724
8722 8742
8763 8773
8782 9702 9722
9743 9753 9763 9773
9782
0703 0713
8762 8772 9742 9752 9762 9772 0702 0712
8720
8741 8751 8761 8771
8780 9700
9721 9731 9741 9751 9761 9771
9780
0701 0711
8740 8750 8760 8770 9720 9730 9740 9750 9760 9770 0700 0710
8628 8648 8668 8688 9608 9628 9648
9669 9679 9689 9699
0608
9668 9678 9688 9698
8626 8666 8686 9606 9626
9647 9657
9666
9687 9697
0606 0626
9646 9686 9696
8684 8694 9604 9614 9624
I
0 500 1,000250
Feet
0 150 30075
Meters
BM5510
D
Nor th Carolina Geodetic Survey bench mark
BM5510
?
BM5510
z
National Geodetic Survey bench mark
Contractor Est. NCFMP Survey bench mark
Panel Contains:
COMMUNITY CID PANEL SUFFIX
8762370058 KSILER CITY,TOWN OF
VERSION NUMBER
2.3.3.2
MAP NUMBER
3710876200K
MAP REVISED
November 17, 2017
PROJECT SITE
PROJECT SITE
3.85 CFS MAX(See DA-4)15" RCP-PIPE A - MAX FLOW
1.2 CFS MAX15" RCP DRIVEWAY PIPE0.73 AC (SEE DA-5)7.52 IN/HR0.22
Summey Engineering Associates, PLLC
Project:Basic Machinery
Job Number:E-5885
Channel Flow Equations
Temporary Ditch 1 - Phase 1
Hydraulic Radius R = A/Pw 0.643462
Area A =6 sf
Wetted Perimeter Pw = 9.324555 ft
Channel Slope S =0.0238 ft/ft
Mannings Coeff.n = 0.02
Trapazoidal Ditch
Bottom Width 3 ft
Side Slope 3 :1
Top Width 9 ft
Depth 1 ft
Manning Equation
Q = (1.49/n)*A*R2/3*S1/2
Q = 51.40 cfs (Ditch Maximum)
Drainage Area
Type Area (AC)C
Bare Earth 0.75 0.5
Impervious 0.00 0.9
Q =CIA
C 0.50
I 7.52 in/hr (10 yr - 5 min Storm)
A 0.75 ac
Q 2.82 cfs (Max Required)
Depth of Flow 0.215 ft (@ required Flow)
Q 2.868766 cfs
A 0.783675 sf
R 0.179751
Pw 4.359779 ft
Top Width 4.29 ft
Outlet Velocity (V)= Q/A
V 3.660657 ft/s
LINER IS REQUIRED
Summey Engineering Associates, PLLC
Project:Basic Machinery
Job Number:E-5885
Channel Flow Equations
Temporary Ditch 1 - Phase 2
Hydraulic Radius R = A/Pw 0.643462
Area A =6 sf
Wetted Perimeter Pw = 9.324555 ft
Channel Slope S =0.0238 ft/ft
Mannings Coeff.n = 0.02
Trapazoidal Ditch
Bottom Width 3 ft
Side Slope 3 :1
Top Width 9 ft
Depth 1 ft
Manning Equation
Q = (1.49/n)*A*R2/3*S1/2
Q = 51.40 cfs (Ditch Maximum)
Drainage Area
Type Area (AC)C
Bare Earth 0.56 0.5
Impervious 0.19 0.9
Q =CIA
C 0.60
I 7.52 in/hr (10 yr - 5 min Storm)
A 0.75 ac
Q 3.39 cfs (Max Required)
Depth of Flow 0.237 ft (@ required Flow)
Q 3.404903 cfs
A 0.879507 sf
R 0.195493
Pw 4.49892 ft
Top Width 4.422 ft
Outlet Velocity (V)= Q/A
V 3.871377 ft/s
LINER IS REQUIRED
Summey Engineering Associates, PLLC
Project:Basic Machinery
Job Number:E-5885
Channel Flow Equations
Permanent Ditch 1 - Construction Phase
Hydraulic Radius R = A/Pw 0.70643
Area A =8 sf
Wetted Perimeter Pw = 11.32456 ft
Channel Slope S =0.02 ft/ft
Mannings Coeff.n = 0.02
Trapazoidal Ditch
Bottom Width 5 ft
Side Slope 3 :1
Top Width 11 ft
Depth 1 ft
Manning Equation
Q = (1.49/n)*A*R2/3*S1/2
Q = 66.86 cfs (Ditch Maximum)
Drainage Area
Type Area (AC)C
Bare Earth 0.56 0.5
Impervious 0.44 0.9
Q =CIA
C 0.68
I 7.52 in/hr (10 yr - 5 min Storm)
A 1.00 ac
Q 5.08 cfs (Max Required)
Depth of Flow 0.239 ft (@ required Flow)
Q 5.08344 cfs
A 1.366363 sf
R 0.209836
Pw 6.511569 ft
Top Width 6.434 ft
Outlet Velocity (V)= Q/A
V 3.720417 ft/s
LINER IS REQUIRED
Summey Engineering Associates, PLLC
Project:Basic Machinery
Job Number:E-5885
Channel Flow Equations
Permanent Ditch 2 - Construction Phase
Hydraulic Radius R = A/Pw 0.70643
Area A =8 sf
Wetted Perimeter Pw = 11.32456 ft
Channel Slope S =0.02 ft/ft
Mannings Coeff.n = 0.02
Trapazoidal Ditch
Bottom Width 5 ft
Side Slope 3 :1
Top Width 11 ft
Depth 1 ft
Manning Equation
Q = (1.49/n)*A*R2/3*S1/2
Q = 66.86 cfs (Ditch Maximum)
Drainage Area
Type Area (AC)C
Bare Earth 0.25 0.5
Impervious 0.58 0.9
Q =CIA
C 0.78
I 7.52 in/hr (10 yr - 5 min Storm)
A 0.83 ac
Q 4.87 cfs (Max Required)
Depth of Flow 0.233 ft (@ required Flow)
Q 4.86591 cfs
A 1.327867 sf
R 0.20512
Pw 6.473621 ft
Top Width 6.398 ft
Outlet Velocity (V)= Q/A
V 3.664456 ft/s
LINER IS REQUIRED
Summey Engineering Associates, PLLC
Project:Basic Machinery
Job Number:E-5885
Channel Flow Equations
Permanent Ditch 1 - Post Construction
Hydraulic Radius R = A/Pw 0.70643
Area A =8 sf
Wetted Perimeter Pw = 11.32456 ft
Channel Slope S =0.02 ft/ft
Mannings Coeff.n = 0.03
Trapazoidal Ditch
Bottom Width 5 ft
Side Slope 3 :1
Top Width 11 ft
Depth 1 ft
Manning Equation
Q = (1.49/n)*A*R2/3*S1/2
Q = 44.57 cfs (Ditch Maximum)
Drainage Area
Type Area (AC)C
Grass 0.56 0.2
Impervious 0.44 0.9
Q =CIA
C 0.51
I 7.52 in/hr (10 yr - 5 min Storm)
A 1.00 ac
Q 3.82 cfs (Max Required)
Depth of Flow 0.2565 ft (@ required Flow)
Q 3.827827 cfs
A 1.479877 sf
R 0.22347
Pw 6.622248 ft
Top Width 6.539 ft
Outlet Velocity (V)= Q/A
V 2.586585 ft/s
LINER IS REQUIRED
Summey Engineering Associates, PLLC
Project:Basic Machinery
Job Number:E-5885
Channel Flow Equations
Permanent Ditch 2 - Post Construction
Hydraulic Radius R = A/Pw 0.70643
Area A =8 sf
Wetted Perimeter Pw = 11.32456 ft
Channel Slope S =0.02 ft/ft
Mannings Coeff.n = 0.03
Trapazoidal Ditch
Bottom Width 5 ft
Side Slope 3 :1
Top Width 11 ft
Depth 1 ft
Manning Equation
Q = (1.49/n)*A*R2/3*S1/2
Q = 44.57 cfs (Ditch Maximum)
Drainage Area
Type Area (AC)C
Grass 0.25 0.2
Impervious 0.58 0.9
Q =CIA
C 0.69
I 7.52 in/hr (10 yr - 5 min Storm)
A 0.83 ac
Q 4.30 cfs (Max Required)
Depth of Flow 0.274 ft (@ required Flow)
Q 4.290244 cfs
A 1.595228 sf
R 0.236929
Pw 6.732928 ft
Top Width 6.644 ft
Outlet Velocity (V)= Q/A
V 2.689424 ft/s
LINER IS REQUIRED