Union Athletic Club - 2017-12-29 Stormwater Impact Analysis

Union County Athletic Complex
Stormwater Impact Analysis / December 2017
1
UNION COUNTY ATHLETIC COMPLEX
Stormwater Impact Analysis
General Description
The Union County Athletic Complex facility is located to the southwest of Genesis Drive and
northeast of the end of Public Works Drive in Monroe, North Carolina. The proposed
development on this site will consist of an athletic complex building, soccer fields, baseball
fields, and supporting street, parking, utility, and stormwater management improvements.
The proposed development is located within the Catawba River basin with stormwater runoff
from the site draining into an East Fork Twelvemile Creek tributary. Development onsite is
limited such that the built upon area is less than 24%. Therefore, stormwater management on this
site shall meet the stormwater performance standards for low-density development set forth in
the North Carolina Administrative Code. These standards are as follows:
15A NCAC 02H .1003 REQUIREMENTS THAT APPLY TO ALL PROJECTS
The following requirements shall apply to projects subject to any North Carolina stormwater program
set forth in Rule .1001 of this Section.
(2)DESIGN REQUIREMENTS FOR LOW DENSITY PROJECTS.Low density projects shall meet
the following minimum design criteria:
(a) DENSITY THRESHOLDS. Low density projects shall not exceed the low density development
thresholds set forth in the stormwater programs to which they are subject pursuant to Rules
.1017, .1019, and .1021 of this Section. For projects subject to the requirements for Non-Coastal
High Quality Waters and Outstanding Resource Waters, dwelling unit per acre may be used
instead of density to establish low density status for single-family detached residential
development as set forth in Rule .1021 in this Section;
(b) DISPERSED FLOW. Projects shall be designed to maximize dispersed flow through
vegetated areas and minimize channelization of flow;
(c) VEGETATED CONVEYANCES. Stormwater that cannot be released as dispersed flow shall
be transported by vegetated conveyances. A minimal amount of non-vegetated conveyances for
erosion protection or piping for driveways or culverts under a road shall be allowed by the
permitting authority when it cannot be avoided. Vegetated conveyances shall meet the following
requirements:
(i) Side slopes shall be no steeper than 3:1 (horizontal to vertical) unless it is
demonstrated to the permitting authority that the soils and vegetation will remain stable
in perpetuity based on engineering calculations and on-site soil investigation; and
(ii) The conveyance shall be designed so that it does not erode during the peak flow from
the 10-year storm as demonstrated by engineering calculations.
(d) CURB OUTLET SYSTEMS. Low density projects may use curb and gutter with outlets to
convey stormwater to grassed swales or vegetated areas. Requirements for these curb outlet
systems shall be as follows:
(i) The curb outlets shall be designed such that the swale or vegetated area can carry the
peak flow from the 10-year storm at a non-erosive velocity;
2
(ii) The longitudinal slope of the swale or vegetated area shall not exceed five percent,
except where not practical due to physical constraints. In these cases, devices to slow the
rate of runoff and encourage infiltration to reduce pollutant delivery shall be provided;
(iii) The swale's cross-section shall be trapezoidal with a minimum bottom width of two
feet;
(iv) The side slopes of the swale or vegetated area shall be no steeper than 3:1
(horizontal to vertical);
(v) The minimum length of the swale or vegetated area shall be 100 feet; and
(vi) Low density projects may use treatment swales designed pursuant to Rule .1061 of
this Section in lieu of the requirements specified in Sub-items (i) through (v) of this Item.
To meet the above standards, a majority of the runoff onsite is directed to three proposed
regenerative stormwater conveyance systems (RSCs) through a series of vegetated swales. The
proposed RSCs will drastically slow the rate of runoff to the downstream waterways and
encourage infiltration to reduce the water quality impact associated with this development. For
the minimal areas unable to be captured by swales and treated using the RSCs, sheet flow is used
to encourage infiltration of runoff. Please note that offsite drainage is conveyed through the site
using standard piping methods.
Calculation Methodology
•Rainfall data for the Monroe, NC region is from NOAA Atlas 14. This data describes a
depth-duration-frequency (DDF) table describing rainfall depth versus time for varying
return periods in the Monroe, NC area. These rainfall depths are input into the
meteorological model within PondPack for peak flow rate calculations. Please reference
the rainfall data section within this report for additional information.
•Using maps contained within the Union County Soil Survey, the on-site soils were
determined to be hydrologic soil group (HSG) ‘B’, ‘C’ and ‘D’ soils. Since the method
chosen to compute post-development peak flow rates and runoff volumes is dependent
upon the soil type, care was taken when selecting the appropriate Soil Conservation
Service Curve Number (SCS CN).
•To be conservative, the post-development times of concentration were assumed to be 5
minutes.
•The post-development cover conditions were determined from the proposed construction
drawings.
•The on- and off-site topography information used in the analysis is from a survey by the
John R. McAdams Company, Inc. and available Monroe GIS data.
•PondPack Version V8i, by Bentley Systems, Inc., was used in determining the pre- &
post-development peak flow rates for the 10-year storm events, as well as routing
calculations for the proposed stormwater management facilities.
•North American Green Erosion Control Materials Design Software (ECMDS) Version
5.0 by Tensar was used in the assigning of liner materials for each treatment swale.
3
•The design and specifications of the regenerative stormwater conveyances were prepared
using the Regenerative Step Pool Storm Conveyance (SPSC) Design Guidelines provided
by Anne Arundel County, Maryland. These design guidelines can be accessed through
http://www.aacounty.org/DPW/Watershed/StepPoolStormConveyance.cfm
Conclusion
If the development on this tract is built as proposed within this report, then the requirements set
forth by the State of North Carolina will be met without additional stormwater management
facilities. However, modifications to the proposed development may require that this analysis be
revised. Some modifications that would require this analysis to be revised include:
1.The proposed site impervious surface exceeds the amount accounted for in this report.
2.The post-development watershed breaks change significantly from those used to prepare
this report.
The above modifications may result in the assumptions within this report becoming invalid. The
computations within this report will need to be revisited if any of the above conditions become
apparent as development of the proposed site moves forward.
1
MISCELLANEOUS SITE
INFORMATION
2 WATERSHED SOILS INFORMATION
5
REGENERATIVE STORMWATER
CONVEYANCE CALCULATIONS
3 POST-DEVELOPMENT
HYDROLOGIC CALCULATIONS
4 SWALE DESIGN CALCULATIONS
UNION COUNTY ATHLETIC COMPLEX
UAC-15000
MISCELLANEOUS SITE INFORMATION
Esri, HERE, DeLorme, MapmyIndia, © OpenStreetMap contributors
0 500 1,000250Feet1 inch = 500 feet
¯UNION COUNTY ATHLETIC COMPLEX
SITE AERIAL MAPPROJECT #: UAC-15000MONROE, NORTH CAROLINA
Copyright:© 2013 National Geographic Society, i-cubed
0 2,000 4,0001,000 Feet1 inch = 2,000 feet
¯UNION COUNTY ATHLETIC COMPLEX
USGS TOPO MAPPROJECT #: UAC-15000MONROE, NORTH CAROLINA
NC DENR - DIVISON OF WATER RESOURCES
Name of Stream Description Class Class Date Index No.
2B .0300
. 0308 CATAWBA RIVER BASIN
Eagle Branch (Watt Lake, Eagle
Lake)
B 03/01/62 11-137-4-2-(1)From source to Dam at Eagle Lake
Eagle Branch C 09/01/74 11-137-4-2-(2)From Dam at Eagle Lake to Coffey
Creek
Maynard Lake C 09/01/74 11-137-4-3Entire lake and connecting stream to
Coffey Creek
Moody Lake C 09/01/74 11-137-4-4Entire lake and connecting stream to
Coffey Creek
Johnson Lake C 09/01/74 11-137-4-5Entire lake and connecting stream to
Coffey Creek
Spratt Lake C 09/01/74 11-137-5Entire lake and connecting stream to
Sugar Creek
Kings Branch C 09/01/74 11-137-6From source to Sugar Creek
McCullough Branch C 09/01/74 11-137-7From source to Sugar Creek
Little Sugar Creek C 09/01/74 11-137-8From source to North Carolina-South
Carolina State Line
Dairy Branch C 09/01/74 11-137-8-1From source to Little Sugar Creek
Brier Creek C 08/01/85 11-137-8-2From source to Little Sugar Creek
Edwards Branch C 03/01/77 11-137-8-2-1From source to Brier Creek
Little Hope Creek C 08/01/85 11-137-8-3From source to Little Sugar Creek
McAlpine Creek (Waverly Lake)C 09/01/74 11-137-9From source to North Carolina-South
Carolina State Line
Campbell Creek C 09/01/74 11-137-9-1From source to McAlpine Creek
Irvins Creek (McEwen Lake)C 09/01/74 11-137-9-2From source to McAlpine Creek
Lake Windermere and Chillis
Lake
C 09/01/74 11-137-9-3Entire lakes and connecting streams
to McAlpine Creek
Fourmile Creek C 09/01/74 11-137-9-4From source to McAlpine Creek
Rocky Branch C 09/01/74 11-137-9-4-1From source to Fourmile Creek
Lake Providence C 09/01/74 11-137-9-4-1-1Entire lake and connecting stream to
Rocky Branch
McMullen Creek C 08/01/85 11-137-9-5From source to McAlpine Creek
Steele Creek C 09/01/74 11-137-10From source to North Carolina-South
Carolina State Line
Walker Branch C 09/01/74 11-137-10-1From source to Steele Creek
Polk Ditch C 09/01/74 11-137-10-1-1From source to Walker Branch
Blankmanship Branch C 09/01/74 11-137-10-2From source to North Carolina-South
Carolina State Line
Clems Branch C 09/01/74 11-137-11From source to North Carolina-South
Carolina State Line
Twelvemile Creek C 03/01/62 11-138From source to North Carolina-South
Carolina State Line
West Fork Twelvemile Creek C 09/01/74 11-138-1From source to Twelvemile Creeek
Culvert Branch C 09/01/74 11-138-1-1From source to West Fork
Twelvemile Creek
Mundys Run C 09/01/74 11-138-1-2From source to West Fork
Twelvemile Creek
East Fork Twelvemile Creek C 09/01/74 11-138-2From source to Twelvemile Creek
Molly Branch C 09/01/74 11-138-2-1From source to East Fork Twelvemile
Creek
31
Legend
Cross-Sections
Base Flood Elevations
Flood Hazard Zones
1% Annual Chance Flood
Regulatory Floodway
Special Floodway
Area of Undetermined Flood Hazard
0.2% Annual C hance Flood
Future C onditions 1% Annual ChanceFlood H azard
Area with R educed Risk Due to Levee
LO MRs
Effective
Map Panels
Digital Data
Unmodernized Maps
Unmapped
USGS The National Map: Orthoimagery
National Flood Hazard Layer FIRMette
0 500 1,000 1,500 2,000250Feet
Ü80°38'43.49"W 35°1'36.17"N 80°38'4.52"W 35°1'5.52"N Date: 5/31/2017 Tim e: 3:09:45 PM
This map complies with FEMA’s standards for the use ofdigital flood maps. The flood hazard information isderived directly from the authoritative NFHL web servicesprovided by FEMA. The base map shown complies withFEMA’s base map accuracy standards.
The NFHL is a living database, updated daily, and thismap represents a snapshot of information at a specifictime.
Flood risks are dynamic and can change frequently due toa variety of factors, including weather patterns, erosion,and new development. FEMA flood maps are continuallyupdated through a variety of processes. Users shouldalways verify through the Map Service Center(http://msc.fema.gov) or the Community Map Repositorythat they have the current effective information.
NFH L maps should not be created for unmapped orunmodernized areas.
UNION COUNTY ATHLETIC COMPLEX
UAC-15000
WATERSHED SOILS INFORMATION
Hydrologic Soil Group—Union County, North Carolina
(Property Line)
Natural Resources
Conservation Service
Web Soil Survey
National Cooperative Soil Survey
5/31/2017
Page 1 of 43875200387530038754003875500387560038757003875800387590038752003875300387540038755003875600387570038758003875900532300532400532500532600532700532800532900533000533100533200533300
532300 532400 532500 532600 532700 532800 532900 533000 533100 533200 533300
35° 1' 31'' N 80° 38' 47'' W35° 1' 31'' N80° 38' 2'' W35° 1' 7'' N
80° 38' 47'' W35° 1' 7'' N
80° 38' 2'' WN
Map projection: Web Mercator Corner coordinates: WGS84 Edge tics: UTM Zone 17N WGS84
0 250 500 1000 1500
Feet
0 50 100 200 300
Meters
Map Scale: 1:5,270 if printed on A landscape (11" x 8.5") sheet.
Soil Map may not be valid at this scale.
MAP LEGEND MAP INFORMATION
Area of Interest (AOI)
Area of Interest (AOI)
Soils
Soil Rating Polygons
A
A/D
B
B/D
C
C/D
D
Not rated or not available
Soil Rating Lines
A
A/D
B
B/D
C
C/D
D
Not rated or not available
Soil Rating Points
A
A/D
B
B/D
C
C/D
D
Not rated or not available
Water Features
Streams and Canals
Transportation
Rails
Interstate Highways
US Routes
Major Roads
Local Roads
Background
Aerial Photography
The soil surveys that comprise your AOI were mapped at
1:24,000.
Warning: Soil Map may not be valid at this scale.
Enlargement of maps beyond the scale of mapping can cause
misunderstanding of the detail of mapping and accuracy of soil
line placement. The maps do not show the small areas of
contrasting soils that could have been shown at a more detailed
scale.
Please rely on the bar scale on each map sheet for map
measurements.
Source of Map: Natural Resources Conservation Service
Web Soil Survey URL:
Coordinate System: Web Mercator (EPSG:3857)
Maps from the Web Soil Survey are based on the Web Mercator
projection, which preserves direction and shape but distorts
distance and area. A projection that preserves area, such as the
Albers equal-area conic projection, should be used if more
accurate calculations of distance or area are required.
This product is generated from the USDA-NRCS certified data as
of the version date(s) listed below.
Soil Survey Area: Union County, North Carolina
Survey Area Data: Version 16, Sep 20, 2016
Soil map units are labeled (as space allows) for map scales
1:50,000 or larger.
Date(s) aerial images were photographed: Feb 11, 2011—Feb
13, 2011
The orthophoto or other base map on which the soil lines were
compiled and digitized probably differs from the background
imagery displayed on these maps. As a result, some minor
shifting of map unit boundaries may be evident.
Hydrologic Soil Group—Union County, North Carolina
(Property Line)
Natural Resources
Conservation Service
Web Soil Survey
National Cooperative Soil Survey
5/31/2017
Page 2 of 4
Hydrologic Soil Group
Hydrologic Soil Group— Summary by Map Unit — Union County, North Carolina (NC179)
Map unit symbol Map unit name Rating Acres in AOI Percent of AOI
BdB2 Badin channery silty
clay loam, 2 to 8
percent slopes,
moderately eroded
C 9.8 19.4%
BdC2 Badin channery silty
clay loam, 8 to 15
percent slopes,
moderately eroded
C 8.6 17.1%
ChA Chewacla silt loam, 0 to
2 percent slopes,
frequently flooded
B/D 4.9 9.8%
CmB Cid channery silt loam, 1
to 5 percent slopes
D 17.7 35.3%
CnB Cid-Urban land
complex, 1 to 5
percent slopes
D 0.0 0.0%
GsB Goldston-Badin
complex, 2 to 8
percent slopes
D 0.3 0.6%
MeB2 Mecklenburg sandy clay
loam, 2 to 8 percent
slopes, moderately
eroded
C 0.4 0.9%
MhA Misenheimer-Cid
complex, 0 to 3
percent slopes
C/D 0.7 1.3%
TaB Tarrus gravelly silt loam,
2 to 8 percent slopes
B 0.4 0.7%
WyB Wynott gravelly loam, 2
to 8 percent slopes
D 7.4 14.8%
Totals for Area of Interest 50.3 100.0%
Hydrologic Soil Group—Union County, North Carolina Property Line
Natural Resources
Conservation Service
Web Soil Survey
National Cooperative Soil Survey
5/31/2017
Page 3 of 4
Description
Hydrologic soil groups are based on estimates of runoff potential. Soils are
assigned to one of four groups according to the rate of water infiltration when the
soils are not protected by vegetation, are thoroughly wet, and receive
precipitation from long-duration storms.
The soils in the United States are assigned to four groups (A, B, C, and D) and
three dual classes (A/D, B/D, and C/D). The groups are defined as follows:
Group A. Soils having a high infiltration rate (low runoff potential) when
thoroughly wet. These consist mainly of deep, well drained to excessively
drained sands or gravelly sands. These soils have a high rate of water
transmission.
Group B. Soils having a moderate infiltration rate when thoroughly wet. These
consist chiefly of moderately deep or deep, moderately well drained or well
drained soils that have moderately fine texture to moderately coarse texture.
These soils have a moderate rate of water transmission.
Group C. Soils having a slow infiltration rate when thoroughly wet. These consist
chiefly of soils having a layer that impedes the downward movement of water or
soils of moderately fine texture or fine texture. These soils have a slow rate of
water transmission.
Group D. Soils having a very slow infiltration rate (high runoff potential) when
thoroughly wet. These consist chiefly of clays that have a high shrink-swell
potential, soils that have a high water table, soils that have a claypan or clay
layer at or near the surface, and soils that are shallow over nearly impervious
material. These soils have a very slow rate of water transmission.
If a soil is assigned to a dual hydrologic group (A/D, B/D, or C/D), the first letter is
for drained areas and the second is for undrained areas. Only the soils that in
their natural condition are in group D are assigned to dual classes.
Rating Options
Aggregation Method: Dominant Condition
Component Percent Cutoff: None Specified
Tie-break Rule: Higher
Hydrologic Soil Group—Union County, North Carolina Property Line
Natural Resources
Conservation Service
Web Soil Survey
National Cooperative Soil Survey
5/31/2017
Page 4 of 4
UNION COUNTY ATHLETIC COMPLEX
UAC-15000
POST DEVELOPMENT HYDROLOGIC
CALCULATIONS
Project Name: Union County Athlethic Complex Date:12/7/2017
Project Number:UAC-15000 Calculated By: J. Mattingly, EI
INPUT SUMMARY
Total Area
Subbasin ID Impervious Open Wooded Pond Total Impervious Open Wooded Pond 1/4-ac Lots Total [acres]SCS CN Tc [min]
1A 4.39 3.00 0.00 0.00 7.39 0.00 0.00 0.00 0.00 0.00 0.00 7.39 90 5.00
1B 0.04 6.01 0.00 0.00 6.05 0.00 0.00 0.00 0.00 0.00 0.00 6.05 80 5.00
2A 0.86 0.58 0.00 0.00 1.44 0.00 0.00 0.00 0.00 0.00 0.00 1.44 90 5.00
2B 2.45 1.60 0.00 0.00 4.05 0.00 0.00 0.00 0.00 0.00 0.00 4.05 89 5.00
2C 0.91 7.95 0.00 0.00 8.86 0.00 0.00 0.00 0.00 0.00 0.00 8.86 78 5.00
3A 0.15 1.71 0.00 0.00 1.86 0.00 0.00 0.00 0.00 0.00 0.00 1.86 81 5.00
3B 0.01 1.34 0.00 0.00 1.35 0.00 0.00 0.00 0.00 0.00 0.00 1.35 80 5.00
3C 0.00 3.92 0.00 0.00 3.92 0.00 0.00 0.00 0.00 0.00 0.00 3.92 79 5.00
4 0.00 0.00 0.00 0.00 0.00 2.98 0.90 0.00 0.00 14.03 3.88 3.88 87 5.00
Bypass 3.17 12.21 0.00 0.00 15.37 0.00 0.00 0.00 0.00 0.00 0.00 15.37 83 5.00
Totals 11.98 38.32 0.00 0.00 50.29 2.98 0.90 0.00 0.00 14.03 3.88 54.17
POST DEVELOPMENT HYDROLOGIC SUMMARY
Onsite Area [acres]Offsite Area [acres]
Project Name: Union County Athlethic Complex Date:12/7/2017
Project Number:UAC-15000 Calculated By: J. Mattingly, EI
Subbasin ID:1A
SCS CURVE NUMBER
(REF: TR-55 and NRCS Web Soil Survey).
HSG Impervious Open Wooded Pond 1/4-ac Lots
A 98 39 30 100 61
B 98 61 55 100 75
C 98 74 70 100 83
D 98 80 77 100 87
HSG 'A' =0%
HSG 'B' =0%
HSG 'C' =47%
HSG 'D' =53%
Cover Composite
Condition SCS CN
Impervious 98
Open 77
Wooded 74
Pond 100
1/4-ac Lots 85
WATERSHED BREAKDOWN
Area Area
[sf][acres]
42,429 0.97
9,271 0.21
139,743 3.21
0 0.00
191,443 4.39
Composite Area Area
SCS CN [sf][acres]
98 191,443 4.39
77 130,470 3.00
74 0 0.00
100 0 0.00
98 0 0.00
77 0 0.00
74 0 0.00
100 0 0.00
85 0 0.00
Total Area =321,913 sf
=7.39 acres
Composite SCS CN =90
% Impervious =59.47%
TIME OF CONCENTRATION
(REF: SCS Segmental Approach, TR-55).
Time of Concentration =5.00 minutes
SCS Lag Time =3.00 minutes
Offsite 1/4-ac Lots Assume 38% impervious
Onsite Open
Onsite Wooded
Onsite Pond
Comments
-
Assume good condition
Assume good condition
-
Contributing Area
Parking
Sidewalk / Concrete
Buildings
Road
Totals
Assume 38% impervious
Offsite Pond -
POST DEVELOPMENT HYDROLOGIC CALCULATIONS
Offsite Impervious -
Offsite Open Assume good condition
Offsite Wooded Assume good condition
Comments
-
Assume good condition
Assume good condition
-
Contributing Area
Onsite Impervious
Project Name: Union County Athlethic Complex Date:12/7/2017
Project Number:UAC-15000 Calculated By: J. Mattingly, EI
Subbasin ID:1B
SCS CURVE NUMBER
(REF: TR-55 and NRCS Web Soil Survey).
HSG Impervious Open Wooded Pond 1/4-ac Lots
A 98 39 30 100 61
B 98 61 55 100 75
C 98 74 70 100 83
D 98 80 77 100 87
HSG 'A' =0%
HSG 'B' =0%
HSG 'C' =0%
HSG 'D' =100%
Cover Composite
Condition SCS CN
Impervious 98
Open 80
Wooded 77
Pond 100
1/4-ac Lots 87
WATERSHED BREAKDOWN
Area Area
[sf][acres]
0 0.00
1,530 0.04
0 0.00
0 0.00
1,530 0.04
Composite Area Area
SCS CN [sf][acres]
98 1,530 0.04
80 261,972 6.01
77 0 0.00
100 0 0.00
98 0 0.00
80 0 0.00
77 0 0.00
100 0 0.00
87 0 0.00
Total Area =263,502 sf
=6.05 acres
Composite SCS CN =80
% Impervious =0.58%
TIME OF CONCENTRATION
(REF: SCS Segmental Approach, TR-55).
Time of Concentration =5.00 minutes
SCS Lag Time =3.00 minutes
Assume 38% impervious
Offsite 1/4-ac Lots Assume 38% impervious
Totals
Contributing Area
Parking
Sidewalk / Concrete
Buildings
Road
Offsite Open Assume good condition
Offsite Wooded Assume good condition
Offsite Pond -
Onsite Wooded Assume good condition
Onsite Pond -
Offsite Impervious -
Contributing Area Comments
Onsite Impervious -
Onsite Open Assume good condition
-
POST DEVELOPMENT HYDROLOGIC CALCULATIONS
Comments
-
Assume good condition
Assume good condition
Project Name: Union County Athlethic Complex Date:12/7/2017
Project Number:UAC-15000 Calculated By: J. Mattingly, EI
Subbasin ID:2A
SCS CURVE NUMBER
(REF: TR-55 and NRCS Web Soil Survey).
HSG Impervious Open Wooded Pond 1/4-ac Lots
A 98 39 30 100 61
B 98 61 55 100 75
C 98 74 70 100 83
D 98 80 77 100 87
HSG 'A' =0%
HSG 'B' =0%
HSG 'C' =15%
HSG 'D' =85%
Cover Composite
Condition SCS CN
Impervious 98
Open 79
Wooded 76
Pond 100
1/4-ac Lots 86
WATERSHED BREAKDOWN
Area Area
[sf][acres]
37,543 0.86
0 0.00
0 0.00
0 0.00
37,543 0.86
Composite Area Area
SCS CN [sf][acres]
98 37,543 0.86
79 25,186 0.58
76 0 0.00
100 0 0.00
98 0 0.00
79 0 0.00
76 0 0.00
100 0 0.00
86 0 0.00
Total Area =62,729 sf
=1.44 acres
Composite SCS CN =90
% Impervious =59.85%
TIME OF CONCENTRATION
(REF: SCS Segmental Approach, TR-55).
Time of Concentration =5.00 minutes
SCS Lag Time =3.00 minutes
Assume 38% impervious
Offsite 1/4-ac Lots Assume 38% impervious
Totals
Contributing Area
Parking
Sidewalk / Concrete
Buildings
Road
Offsite Open Assume good condition
Offsite Wooded Assume good condition
Offsite Pond -
Onsite Wooded Assume good condition
Onsite Pond -
Offsite Impervious -
Contributing Area Comments
Onsite Impervious -
Onsite Open Assume good condition
-
POST DEVELOPMENT HYDROLOGIC CALCULATIONS
Comments
-
Assume good condition
Assume good condition
Project Name: Union County Athlethic Complex Date:12/7/2017
Project Number:UAC-15000 Calculated By: J. Mattingly, EI
Subbasin ID:2B
SCS CURVE NUMBER
(REF: TR-55 and NRCS Web Soil Survey).
HSG Impervious Open Wooded Pond 1/4-ac Lots
A 98 39 30 100 61
B 98 61 55 100 75
C 98 74 70 100 83
D 98 80 77 100 87
HSG 'A' =0%
HSG 'B' =0%
HSG 'C' =75%
HSG 'D' =25%
Cover Composite
Condition SCS CN
Impervious 98
Open 76
Wooded 72
Pond 100
1/4-ac Lots 84
WATERSHED BREAKDOWN
Area Area
[sf][acres]
48,188 1.11
9,129 0.21
49,290 1.13
0 0.00
106,607 2.45
Composite Area Area
SCS CN [sf][acres]
98 106,607 2.45
76 69,800 1.60
72 0 0.00
100 0 0.00
98 0 0.00
76 0 0.00
72 0 0.00
100 0 0.00
84 0 0.00
Total Area =176,407 sf
=4.05 acres
Composite SCS CN =89
% Impervious =60.43%
TIME OF CONCENTRATION
(REF: SCS Segmental Approach, TR-55).
Time of Concentration =5.00 minutes
SCS Lag Time =3.00 minutes
Assume 38% impervious
Offsite 1/4-ac Lots Assume 38% impervious
Totals
Contributing Area
Parking
Sidewalk / Concrete
Buildings
Road
-
POST DEVELOPMENT HYDROLOGIC CALCULATIONS
Comments
-
Assume good condition
Assume good condition
Contributing Area Comments
Onsite Impervious -
Onsite Open Assume good condition
Onsite Wooded Assume good condition
Onsite Pond -
Offsite Impervious -
Offsite Open Assume good condition
Offsite Wooded Assume good condition
Offsite Pond -
Project Name: Union County Athlethic Complex Date:12/7/2017
Project Number:UAC-15000 Calculated By: J. Mattingly, EI
Subbasin ID:2C
SCS CURVE NUMBER
(REF: TR-55 and NRCS Web Soil Survey).
HSG Impervious Open Wooded Pond 1/4-ac Lots
A 98 39 30 100 61
B 98 61 55 100 75
C 98 74 70 100 83
D 98 80 77 100 87
HSG 'A' =0%
HSG 'B' =0%
HSG 'C' =79%
HSG 'D' =21%
Cover Composite
Condition SCS CN
Impervious 98
Open 75
Wooded 71
Pond 100
1/4-ac Lots 84
WATERSHED BREAKDOWN
Area Area
[sf][acres]
1,049 0.02
13,930 0.32
24,855 0.57
0 0.00
39,834 0.91
Composite Area Area
SCS CN [sf][acres]
98 39,834 0.91
75 346,283 7.95
71 0 0.00
100 0 0.00
98 0 0.00
75 0 0.00
71 0 0.00
100 0 0.00
84 0 0.00
Total Area =386,117 sf
=8.86 acres
Composite SCS CN =78
% Impervious =10.32%
TIME OF CONCENTRATION
(REF: SCS Segmental Approach, TR-55).
Time of Concentration =5.00 minutes
SCS Lag Time =3.00 minutes
Assume 38% impervious
Offsite 1/4-ac Lots Assume 38% impervious
Totals
Contributing Area
Parking
Sidewalk / Concrete
Buildings
Road
-
POST DEVELOPMENT HYDROLOGIC CALCULATIONS
Comments
-
Assume good condition
Assume good condition
Contributing Area Comments
Onsite Impervious -
Onsite Open Assume good condition
Onsite Wooded Assume good condition
Onsite Pond -
Offsite Impervious -
Offsite Open Assume good condition
Offsite Wooded Assume good condition
Offsite Pond -
Project Name: Union County Athlethic Complex Date:12/7/2017
Project Number:UAC-15000 Calculated By: J. Mattingly, EI
Subbasin ID:3A
SCS CURVE NUMBER
(REF: TR-55 and NRCS Web Soil Survey).
HSG Impervious Open Wooded Pond 1/4-ac Lots
A 98 39 30 100 61
B 98 61 55 100 75
C 98 74 70 100 83
D 98 80 77 100 87
HSG 'A' =0%
HSG 'B' =0%
HSG 'C' =0%
HSG 'D' =100%
Cover Composite
Condition SCS CN
Impervious 98
Open 80
Wooded 77
Pond 100
1/4-ac Lots 87
WATERSHED BREAKDOWN
Area Area
[sf][acres]
5,035 0.12
1,325 0.03
0 0.00
0 0.00
6,360 0.15
Composite Area Area
SCS CN [sf][acres]
98 6,360 0.15
80 74,536 1.71
77 0 0.00
100 0 0.00
98 0 0.00
80 0 0.00
77 0 0.00
100 0 0.00
87 0 0.00
Total Area =80,896 sf
=1.86 acres
Composite SCS CN =81
% Impervious =7.86%
TIME OF CONCENTRATION
(REF: SCS Segmental Approach, TR-55).
Time of Concentration =5.00 minutes
SCS Lag Time =3.00 minutes
Assume 38% impervious
Offsite 1/4-ac Lots Assume 38% impervious
Totals
Contributing Area
Parking
Sidewalk / Concrete
Buildings
Road
-
POST DEVELOPMENT HYDROLOGIC CALCULATIONS
Comments
-
Assume good condition
Assume good condition
Contributing Area Comments
Onsite Impervious -
Onsite Open Assume good condition
Onsite Wooded Assume good condition
Onsite Pond -
Offsite Impervious -
Offsite Open Assume good condition
Offsite Wooded Assume good condition
Offsite Pond -
Project Name: Union County Athlethic Complex Date:12/7/2017
Project Number:UAC-15000 Calculated By: J. Mattingly, EI
Subbasin ID:3B
SCS CURVE NUMBER
(REF: TR-55 and NRCS Web Soil Survey).
HSG Impervious Open Wooded Pond 1/4-ac Lots
A 98 39 30 100 61
B 98 61 55 100 75
C 98 74 70 100 83
D 98 80 77 100 87
HSG 'A' =0%
HSG 'B' =0%
HSG 'C' =0%
HSG 'D' =100%
Cover Composite
Condition SCS CN
Impervious 98
Open 80
Wooded 77
Pond 100
1/4-ac Lots 87
WATERSHED BREAKDOWN
Area Area
[sf][acres]
0 0.00
386 0.01
0 0.00
0 0.00
386 0.01
Composite Area Area
SCS CN [sf][acres]
98 386 0.01
80 58,336 1.34
77 0 0.00
100 0 0.00
98 0 0.00
80 0 0.00
77 0 0.00
100 0 0.00
87 0 0.00
Total Area =58,722 sf
=1.35 acres
Composite SCS CN =80
% Impervious =0.66%
TIME OF CONCENTRATION
(REF: SCS Segmental Approach, TR-55).
Time of Concentration =5.00 minutes
SCS Lag Time =3.00 minutes
Assume 38% impervious
Offsite 1/4-ac Lots Assume 38% impervious
Totals
Contributing Area
Parking
Sidewalk / Concrete
Buildings
Road
-
POST DEVELOPMENT HYDROLOGIC CALCULATIONS
Comments
-
Assume good condition
Assume good condition
Contributing Area Comments
Onsite Impervious -
Onsite Open Assume good condition
Onsite Wooded Assume good condition
Onsite Pond -
Offsite Impervious -
Offsite Open Assume good condition
Offsite Wooded Assume good condition
Offsite Pond -
Project Name: Union County Athlethic Complex Date:12/7/2017
Project Number:UAC-15000 Calculated By: J. Mattingly, EI
Subbasin ID:3C
SCS CURVE NUMBER
(REF: TR-55 and NRCS Web Soil Survey).
HSG Impervious Open Wooded Pond 1/4-ac Lots
A 98 39 30 100 61
B 98 61 55 100 75
C 98 74 70 100 83
D 98 80 77 100 87
HSG 'A' =0%
HSG 'B' =0%
HSG 'C' =14%
HSG 'D' =86%
Cover Composite
Condition SCS CN
Impervious 98
Open 79
Wooded 76
Pond 100
1/4-ac Lots 86
WATERSHED BREAKDOWN
Area Area
[sf][acres]
0 0.00
0 0.00
0 0.00
0 0.00
0 0.00
Composite Area Area
SCS CN [sf][acres]
98 0 0.00
79 170,880 3.92
76 0 0.00
100 0 0.00
98 0 0.00
79 0 0.00
76 0 0.00
100 0 0.00
86 0 0.00
Total Area =170,880 sf
=3.92 acres
Composite SCS CN =79
% Impervious =0.00%
TIME OF CONCENTRATION
(REF: SCS Segmental Approach, TR-55).
Time of Concentration =5.00 minutes
SCS Lag Time =3.00 minutes
Assume 38% impervious
Offsite 1/4-ac Lots Assume 38% impervious
Totals
Contributing Area
Parking
Sidewalk / Concrete
Buildings
Road
-
POST DEVELOPMENT HYDROLOGIC CALCULATIONS
Comments
-
Assume good condition
Assume good condition
Contributing Area Comments
Onsite Impervious -
Onsite Open Assume good condition
Onsite Wooded Assume good condition
Onsite Pond -
Offsite Impervious -
Offsite Open Assume good condition
Offsite Wooded Assume good condition
Offsite Pond -
Project Name: Union County Athlethic Complex Date:12/7/2017
Project Number:UAC-15000 Calculated By: J. Mattingly, EI
Subbasin ID:4
SCS CURVE NUMBER
(REF: TR-55 and NRCS Web Soil Survey).
HSG Impervious Open Wooded Pond 1/4-ac Lots
A 98 39 30 100 61
B 98 61 55 100 75
C 98 74 70 100 83
D 98 80 77 100 87
HSG 'A' =0%
HSG 'B' =0%
HSG 'C' =37%
HSG 'D' =63%
Cover Composite
Condition SCS CN
Impervious 98
Open 78
Wooded 74
Pond 100
1/4-ac Lots 86
WATERSHED BREAKDOWN
Area Area
[sf][acres]
0 0.00
0 0.00
0 0.00
0 0.00
0 0.00
Composite Area Area
SCS CN [sf][acres]
98 0 0.00
78 0 0.00
74 0 0.00
100 0 0.00
98 129,614 2.98
78 39,292 0.90
74 0 0.00
100 0 0.00
86 611,049 14.03
Total Area =779,955 sf
=17.91 acres
Composite SCS CN =87
% Impervious =46.39%
TIME OF CONCENTRATION
(REF: SCS Segmental Approach, TR-55).
Time of Concentration =5.00 minutes
SCS Lag Time =3.00 minutes
Offsite 1/4-ac Lots Assume 38% impervious
Assume 38% impervious
Offsite Open Assume good condition
Offsite Wooded Assume good condition
Offsite Pond -
Onsite Wooded Assume good condition
Onsite Pond -
Offsite Impervious -
Contributing Area Comments
Onsite Impervious -
Onsite Open Assume good condition
Contributing Area
Parking
Sidewalk / Concrete
Buildings
Road
Totals
POST DEVELOPMENT HYDROLOGIC CALCULATIONS
Comments
-
Assume good condition
Assume good condition
-
Project Name: Union County Athlethic Complex Date:12/7/2017
Project Number:UAC-15000 Calculated By: J. Mattingly, EI
Subbasin ID:Bypass
SCS CURVE NUMBER
(REF: TR-55 and NRCS Web Soil Survey).
HSG Impervious Open Wooded Pond 1/4-ac Lots
A 98 39 30 100 61
B 98 61 55 100 75
C 98 74 70 100 83
D 98 80 77 100 87
HSG 'A' =0%
HSG 'B' =3%
HSG 'C' =15%
HSG 'D' =82%
Cover Composite
Condition SCS CN
Impervious 98
Open 79
Wooded 75
Pond 100
1/4-ac Lots 86
WATERSHED BREAKDOWN
Area Area
[sf][acres]
101,032 2.32
24,248 0.56
0 0.00
12,691 0.29
137,971 3.17
Composite Area Area
SCS CN [sf][acres]
98 137,971 3.17
79 531,695 12.21
75 0 0.00
100 0 0.00
98 0 0.00
79 0 0.00
75 0 0.00
100 0 0.00
86 0 0.00
Total Area =669,666 sf
=15.37 acres
Composite SCS CN =83
% Impervious =20.60%
TIME OF CONCENTRATION
(REF: SCS Segmental Approach, TR-55).
Time of Concentration =5.00 minutes
SCS Lag Time =3.00 minutes
Assume 38% impervious
Offsite 1/4-ac Lots Assume 38% impervious
Totals
Contributing Area
Parking
Sidewalk / Concrete
Buildings
Road
Offsite Open Assume good condition
Offsite Wooded Assume good condition
Offsite Pond -
Onsite Wooded Assume good condition
Onsite Pond -
Offsite Impervious -
Contributing Area Comments
Onsite Impervious -
Onsite Open Assume good condition
-
POST DEVELOPMENT HYDROLOGIC CALCULATIONS
Comments
-
Assume good condition
Assume good condition
4
Bypass
3C 3B 3A
2C 2B 2A1B1A
POA 4
POA 1B
POA 2C
POA 3C POA 3B
POA 2B
POA 3A
POA 2A
POA 1A
Bypass
12/7/2017UAC15000.ppc
J. MattinglyUnion County Athletic Complex
Subsection: Master Network Summary
Catchments Summary
Peak Flow
(ft³/s)
Time to Peak
(min)
Hydrograph
Volume
(ac-ft)
Return
Event
(years)
ScenarioLabel
46.87721.002.5751010 Year Flow1A
29.99721.001.5981010 Year Flow1B
9.13721.000.5021010 Year Flow2A
25.19721.001.3751010 Year Flow2B
41.27721.002.2011010 Year Flow2C
9.49721.000.5061010 Year Flow3A
6.69721.000.3571010 Year Flow3B
18.85721.001.0041010 Year Flow3C
82.95721.004.4331010 Year FlowBypass
Node Summary
Peak Flow
(ft³/s)
Time to Peak
(min)
Hydrograph
Volume
(ac-ft)
Return
Event
(years)
ScenarioLabel
82.95721.004.4331010 Year FlowBypass
76.85721.004.1731010 Year FlowPOA 1A
29.99721.001.5981010 Year FlowPOA 1B
75.59721.004.0781010 Year FlowPOA 2A
66.46721.003.5761010 Year FlowPOA 2B
41.27721.002.2011010 Year FlowPOA 2C
35.03721.001.8671010 Year FlowPOA 3A
25.54721.001.3611010 Year FlowPOA 3B
18.85721.001.0041010 Year FlowPOA 3C
12/7/2017UAC15000.ppc
J. MattinglyUnion County Athletic Complex
UNION COUNTY ATHLETIC COMPLEX
UAC-15000
SWALE DESIGN CALCULATIONS
Project Name: Union Athletic Club Date:12/7/2017
Project Number:UAC-15000 Calculated By: J. Mattingly, EI
RELEASE RATE MANAGEMENT RESULTS
Flow
Return Period [cfs]
10-Year 76.85
Flow
Return Period [cfs]
10-Year 29.99
Flow
Return Period [cfs]
10-Year 75.59
Flow
Return Period [cfs]
10-Year 66.46
Flow
Return Period [cfs]
10-Year 41.27
Flow
Return Period [cfs]
10-Year 35.03
Flow
Return Period [cfs]
10-Year 25.54
Flow
Return Period [cfs]
10-Year 18.85
POINT OF ANALYSIS #3B
POINT OF ANALYSIS #3
POINT OF ANALYSIS #2C
POINT OF ANALYSIS #2B
SUMMARY OF RESULTS
POINT OF ANALYSIS #1A
POINT OF ANALYSIS #1B
POINT OF ANALYSIS #2A
POINT OF ANALYSIS #3A
Project Name: Union Athletic Club Date:12/8/2017
Project Number:UAC-15000 Calculated By: J. Mattingly, EI
CHANNEL 1A SUMMARY
Design Drainage Area =13.44 acres
Design Impervious Area =4.43 acres
% Impervious =33.0%
Design Discharge =76.85 cfs
Channel Slope =3%
Right Side Slope =3
Left Side Slope =3
Bottom Width =2
Velocity =5.86 ft/s
Channel Lining =SC250
CHANNEL 1B SUMMARY
Design Drainage Area =6.05 acres
Design Impervious Area =0.04 acres
% Impervious =0.6%
Design Discharge =29.99 cfs
Channel Slope =1.0%
Right Side Slope =3
Left Side Slope =3
Bottom Width =2
Velocity =3.58 ft/s
Channel Lining =S150BN
SUMMARY OF RESULTS
CHANNEL 2A SUMMARY
Design Drainage Area =14.35 acres
Design Impervious Area =4.22 acres
% Impervious =29.4%
Design Discharge =75.59 cfs
Channel Slope =1%
Right Side Slope =2
Left Side Slope =2
Bottom Width =4
Velocity =5.85 ft/s
Channel Lining =S150BN
CHANNEL 2B SUMMARY
Design Drainage Area =12.91 acres
Design Impervious Area =3.36 acres
% Impervious =26.0%
Design Discharge =66.46 cfs
Channel Slope =1%
Right Side Slope =2.5
Left Side Slope =2.5
Bottom Width =2
Velocity =5.74 ft/s
Channel Lining =S150BN
CHANNEL 2C SUMMARY
Design Drainage Area =8.86 acres
Design Impervious Area =0.91 acres
% Impervious =10.3%
Design Discharge =41.27 cfs
Channel Slope =1.25%
Right Side Slope =3
Left Side Slope =3
Bottom Width =2
Velocity =4.42 ft/s
Channel Lining =S150BN
CHANNEL 3A SUMMARY
Design Drainage Area =7.13 acres
Design Impervious Area =0.15 acres
% Impervious =2.2%
Design Discharge =35.03 cfs
Channel Slope =1%
Right Side Slope =2
Left Side Slope =2
Bottom Width =2
Velocity =4.41 ft/s
Channel Lining =S150BN
CHANNEL 3B SUMMARY
Design Drainage Area =5.27 acres
Design Impervious Area =0.01 acres
% Impervious =0.2%
Design Discharge =25.54 cfs
Channel Slope =1%
Right Side Slope =2
Left Side Slope =2
Bottom Width =1
Velocity =4.06 ft/s
Channel Lining =S150BN
CHANNEL 3C SUMMARY
Design Drainage Area =3.92 acres
Design Impervious Area =0.00 acres
% Impervious =0.0%
Design Discharge =18.85 cfs
Channel Slope =1%
Right Side Slope =3
Left Side Slope =3
Bottom Width =1
Velocity =3.26 ft/s
Channel Lining =S150BN
UNION COUNTY ATHLETIC COMPLEX
UAC-15000
REGENERATIVE STORMWATER
CONVEYANCE DESIGN CALCULATIONS
Project Description
Friction Method Manning Formula
Solve For Normal Depth
Input Data
Roughness Coefficient 0.069
Channel Slope 0.05000 ft/ft
Left Side Slope 3.00 ft/ft (H:V)
Right Side Slope 3.00 ft/ft (H:V)
Bottom Width 12.00 ft
Discharge 77.00 ft³/s
Results
Normal Depth 1.12 ft
Flow Area 17.16 ft²
WettedPerimeter 19.07 ft
Hydraulic Radius 0.90 ft
Top Width 18.71 ft
Critical Depth 0.99 ft
Critical Slope 0.07561 ft/ft
Velocity 4.49 ft/s
Velocity Head 0.31 ft
Specific Energy 1.43 ft
Froude Number 0.83
Flow Type Subcritical
GVF Input Data
Downstream Depth 0.00 ft
Length 0.00 ft
Number Of Steps 0
GVF Output Data
Upstream Depth 0.00 ft
Profile Description
Profile Headloss 0.00 ft
Downstream Velocity Infinity ft/s
Upstream Velocity Infinity ft/s
Normal Depth 1.12 ft
Critical Depth 0.99 ft
Channel Slope 0.05000 ft/ft
Critical Slope 0.07561 ft/ft
Worksheet for Trapezoidal Channel - Riffle RSC 1
12/14/2017 3:03:35 PM
Bentley Systems, Inc.Bentley FlowMaster V8i (SELECTseries 1) [08.11.01.03]
27 Siemons Company Drive Suite 200 W Watertown, CT 06795 USA [phone]of1Page
Project Description
Friction Method Manning Formula
Solve For Normal Depth
Input Data
Roughness Coefficient 0.069
Channel Slope 0.05000 ft/ft
Left Side Slope 3.00 ft/ft (H:V)
Right Side Slope 3.00 ft/ft (H:V)
Bottom Width 12.00 ft
Discharge 76.00 ft³/s
Results
Normal Depth 1.11 ft
Flow Area 17.00 ft²
WettedPerimeter 19.02 ft
Hydraulic Radius 0.89 ft
Top Width 18.66 ft
Critical Depth 0.99 ft
Critical Slope 0.07578 ft/ft
Velocity 4.47 ft/s
Velocity Head 0.31 ft
Specific Energy 1.42 ft
Froude Number 0.83
Flow Type Subcritical
GVF Input Data
Downstream Depth 0.00 ft
Length 0.00 ft
Number Of Steps 0
GVF Output Data
Upstream Depth 0.00 ft
Profile Description
Profile Headloss 0.00 ft
Downstream Velocity Infinity ft/s
Upstream Velocity Infinity ft/s
Normal Depth 1.11 ft
Critical Depth 0.99 ft
Channel Slope 0.05000 ft/ft
Critical Slope 0.07578 ft/ft
Worksheet for Trapezoidal Channel - Riffle RSC 2
12/14/2017 3:03:58 PM
Bentley Systems, Inc.Bentley FlowMaster V8i (SELECTseries 1) [08.11.01.03]
27 Siemons Company Drive Suite 200 W Watertown, CT 06795 USA [phone]of1Page
Project Description
Friction Method Manning Formula
Solve For Normal Depth
Input Data
Roughness Coefficient 0.069
Channel Slope 0.02500 ft/ft
Left Side Slope 3.00 ft/ft (H:V)
Right Side Slope 3.00 ft/ft (H:V)
Bottom Width 12.00 ft
Discharge 36.00 ft³/s
Results
Normal Depth 0.88 ft
Flow Area 12.96 ft²
WettedPerimeter 17.59 ft
Hydraulic Radius 0.74 ft
Top Width 17.31 ft
Critical Depth 0.62 ft
Critical Slope 0.08632 ft/ft
Velocity 2.78 ft/s
Velocity Head 0.12 ft
Specific Energy 1.00 ft
Froude Number 0.57
Flow Type Subcritical
GVF Input Data
Downstream Depth 0.00 ft
Length 0.00 ft
Number Of Steps 0
GVF Output Data
Upstream Depth 0.00 ft
Profile Description
Profile Headloss 0.00 ft
Downstream Velocity Infinity ft/s
Upstream Velocity Infinity ft/s
Normal Depth 0.88 ft
Critical Depth 0.62 ft
Channel Slope 0.02500 ft/ft
Critical Slope 0.08632 ft/ft
Worksheet for Trapezoidal Channel - Riffle RSC 3
12/14/2017 3:04:24 PM
Bentley Systems, Inc.Bentley FlowMaster V8i (SELECTseries 1) [08.11.01.03]
27 Siemons Company Drive Suite 200 W Watertown, CT 06795 USA [phone]of1Page
τb = γ*y*Sf
Channel Left Bank Right Bank
ft ft ft ft Left Bank Right Bank Left Bank Right Bank Left Bank Right Bank lb/ft3 lb/ft2 lb/ft2 lb/ft2
1 10-yr 0.05 1.12 1.12 0 12 10.7 3 3 3 3 0.85 0.85 62.4 3.49 2.97 2.97
2 10-yr 0.05 1.11 1.11 0 12 10.8 3 3 3 3 0.85 0.85 62.4 3.46 2.94 2.94
3 10-yr 0.025 0.88 0.88 0 12 13.6 3 3 3 3 0.85 0.85 62.4 1.37 1.17 1.17
WSELSfXS Depth, y
τs = Ks*γ*y*SfγWidth b Side-Slope 1:Z KsInter Side-Slope mWidth-
Depth b/y
Channel
InvertScenarioProfile

ERDC TN-EMRRP SR-29 5
Table 2. Permissible Shear and Velocity for Selected Lining Materials1
Boundary Category Boundary Type
Permissible
Shear Stress
(lb/sq ft)
Permissible
Velocity
(ft/sec)
Citation(s)
Soils Fine colloidal sand 0.02 - 0.03 1.5 A
Sandy loam (noncolloidal) 0.03 - 0.04 1.75 A
Alluvial silt (noncolloidal) 0.045 - 0.05 2 A
Silty loam (noncolloidal) 0.045 - 0.05 1.75 – 2.25 A
Firm loam 0.075 2.5 A
Fine gravels 0.075 2.5 A
Stiff clay 0.26 3 – 4.5 A, F
Alluvial silt (colloidal) 0.26 3.75 A
Graded loam to cobbles 0.38 3.75 A
Graded silts to cobbles 0.43 4 A
Shales and hardpan 0.67 6 A
Gravel/Cobble 1-in. 0.33 2.5 – 5 A
2-in. 0.67 3 – 6 A
6-in. 2.0 4 – 7.5 A
12-in. 4.0 5.5 – 12 A
Vegetation Class A turf 3.7 6 – 8 E, N
Class B turf 2.1 4 - 7 E, N
Class C turf 1.0 3.5 E, N
Long native grasses 1.2 – 1.7 4 – 6 G, H, L, N
Short native and bunch grass 0.7 - 0.95 3 – 4 G, H, L, N
Reed plantings 0.1-0.6 N/A E, N
Hardwood tree plantings 0.41-2.5 N/A E, N
Temporary Degradable RECPs Jute net 0.45 1 – 2.5 E, H, M
Straw with net 1.5 – 1.65 1 – 3 E, H, M
Coconut fiber with net 2.25 3 – 4 E, M
Fiberglass roving 2.00 2.5 – 7 E, H, M
Non-Degradable RECPs Unvegetated 3.00 5 – 7 E, G, M
Partially established 4.0-6.0 7.5 – 15 E, G, M
Fully vegetated 8.00 8 – 21 F, L, M
Riprap 6 – in. d50 2.5 5 – 10 H
9 – in. d50 3.8 7 – 11 H
12 – in. d50 5.1 10 – 13 H
18 – in. d50 7.6 12 – 16 H
24 – in. d50 10.1 14 – 18 E
Soil Bioengineering Wattles 0.2 – 1.0 3 C, I, J, N
Reed fascine 0.6-1.25 5 E
Coir roll 3 - 5 8 E, M, N
Vegetated coir mat 4 - 8 9.5 E, M, N
Live brush mattress (initial) 0.4 – 4.1 4 B, E, I
Live brush mattress (grown) 3.90-8.2 12 B, C, E, I, N
Brush layering (initial/grown) 0.4 – 6.25 12 E, I, N
Live fascine 1.25-3.10 6 – 8 C, E, I, J
Live willow stakes 2.10-3.10 3 – 10 E, N, O
Hard Surfacing Gabions 10 14 – 19 D
Concrete 12.5 >18 H
1 Ranges of values generally reflect multiple sources of data or different testing conditions.
A. Chang, H.H. (1988). F. Julien, P.Y. (1995). K. Sprague, C.J. (1999).
B. Florineth. (1982) G. Kouwen, N.; Li, R. M.; and Simons , D.B., (1980). L. Temple, D.M. (1980).
C. Gerstgraser, C. (1998). H. Norman, J. N. (1975). M. TXDOT (1999)
D. Goff, K. (1999). I. Schiechtl, H. M. and R. Stern. (1996). N. Data from Author (2001)
E. Gray, D.H., and Sotir, R.B. (1996). J. Schoklitsch, A. (1937). O. USACE (1997).
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