SW3200302_2019-07-19 Belshire SIA_4/6/2020

BELSHIRE OF WAXHAW
Stormwater Impact Analysis & Final Design of Stormwater Control Measures
NARRATIVE > COU-15000
creating experiences through experience 3436 Toringdon Way, Suite 110, Charlotte, NC 28277 / 704. 527. 0800
GENERAL DESCRIPTION
The proposed Belshire of Waxhaw development is located on the southeast corner of Waxhaw Marvin
Road and Helms Road in Waxhaw, North Carolina. The proposed development on this site will consist of
single-family homes and townhomes, in addition to streets, parking, associated utilities, and stormwater
control measures.
The proposed development is located within the Catawba River Basin with stormwater runoff from the
site draining to Rone Branch. Per Town of Waxhaw regulations, stormwater management on this site
shall meet the stormwater performance standards outlined in the Town of Waxhaw Stormwater
Ordinance. These are as follows:
103. Standards for plan approval.
The following standards shall be met for approval of a storm water drainage plan:
(1) The Town Engineer shall review the drainage plan for compliance with the standards
contained in the Town of Waxhaw Storm Water Design Manual”, Waxhaw, N.C., the current
edition of the “Charlotte-Mecklenburg Land Development Standards Manual”, and any other
relevant and appropriate standard established by the Town Engineer.
(2) The Town Engineer will not approve a drainage plan if the impervious ground cover
proposed in the plan would increase the peak level of storm water runoff from the site, unless
the drainage plan identifies measures to control and limit runoffs to peak levels no greater than
would occur from the site if left in its natural, undeveloped condition.
(3) All storm water collection and drainage systems shall be designed in compliance with the
Charlotte Mecklenburg Land Development Standards Manual and as stated under (1) above.
In order to meet the above applicable standards, the existing pond will be enhanced to meet detention
requirements and two sand filters are proposed to meet water quality requirements. This report serves
as the stormwater impact analysis for the proposed development and includes design calculations for
these facilities.
CALCULATION METHODOLOGY
>Rainfall data for the analysis was taken from NOAA Atlas 14. Please reference the precipitation
information 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’ 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). A composite SCS CN
was computed for each pre- and post-development subbasin. For example, Subbasin #1 in the
NARRATIVE > COU-15000
creating experiences through experience 2 of 3
pre-development analysis consists of approximately 100% HSG ‘B’ soils. Therefore, for the open
area cover condition, the composite SCS CN is computed as follows (assuming good condition):
Composite Open SCS CN = (100%x 61) = 61
>A composite SCS Curve Number was calculated for both the pre- and post-development
condition for each subbasin using SCS curve numbers and land cover conditions. Land cover
conditions for the pre-development condition were taken from available survey and GIS
information, as well as a recent survey by McAdams. Land cover conditions for the post-
development condition were taken from the proposed development plan.
>The time of concentration was calculated using SCS TR-55 (Segmental Approach, 1986). The Tc
flow path was divided into three segments: overland flow, concentrated flow, and channel flow.
The travel time was then computed for each segment, from which the overall time of
concentration was determined by taking the sum of each segmental time.
>PondPack Version V8i was used in determining the pre- & post- development peak flow rates for
the 2-, 10-, 25-, and 100-year storm events, as well as routing calculations for the proposed
stormwater management facilities.
>The proposed stormwater control measures were designed in accordance with the Minimum
Design Criteria (MDC) standards set forth in the NCDEQ Stormwater Design Manual.
DISCUSSION OF RESULTS
The proposed stormwater management plan for the site addresses both water quantity (peak runoff
control) and water quality requirements. Most of the runoff from the site is directed to two splitter
boxes. In the water quality event, these splitter boxes direct flow to the proposed sand filters (SCM A
and SCM B). The splitter boxes direct any runoff exceeding the water quality volume to the enhanced
existing pond for detention.
Peak Runoff Control Requirements:
The proposed pond retrofit has been designed to provide the necessary on-site peak runoff control such
that there are no increases in the 2-, 10-, 25-, and 100-year storm events at the downstream Point of
Analysis (POA 1).
Water Quality Requirements:
As discussed above, the splitter boxes direct the water quality volume to flow into the two proposed
sand filters (SCM A and SCM B) to be treated per requirements. The proposed stormwater control
measures were designed in accordance with the Minimum Design Criteria (MDC) standards set forth in
the NCDEQ Stormwater Design Manual.
NARRATIVE > COU-15000
creating experiences through experience 3 of 3
CONCLUSION
If the development on this tract is built as proposed within this report, then the requirements set forth
in Town of Waxhaw Development Ordinance will be met. However, modifications to the proposed
development may require that this analysis be revised. Some modifications that would require this
analysis to be revised include:
>The proposed site impervious surface exceeds the amount accounted for in this report.
>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.
3 WATERSHED SOILS INFORMATION
4 PRECIPITATION DATA
1 SUMMARY OF RESULTS
2 MISCELLANEOUS SITE INFORMATION
9 DESIGN OF POND RETROFIT
5 PRE-DEVELOPMENT HYDROLOGIC CALCULATIONS
8 DESIGN OF STORMWATER CONTORL MEASURE B
6 POST-DEVELOPMENT HYDROLOGIC CALCULATIONS
7 DESIGN OF STORMWATER CONTROL MEASURE A
BELSHIRE OF WAXHAW
COU-15000

SUMMARY OF RESULTS

Project Name: Belshire Subdivision Date: 7/17/2019
Project Number: COU-15000 Calculated By: J. Mattingly
RELEASE RATE MANAGEMENT RESULTS
Pre-Dev Post-Dev
Return Period [cfs][cfs]% Increase
2-Year 12.83 12.82 0%
10-Year 38.67 29.39 -24%
25-Year 55.47 35.76 -36%
100-Year 81.60 61.52 -25%
SUMMARY OF RESULTS
POINT OF ANALYSIS #1
Project Name: Belshire Subdivision Date: 7/17/2019
Project Number: COU-15000 Calculated By: J. Mattingly
DETENTION SUMMARY
Design Drainage Area =11.70 acres
Design Impervious Area =5.12 acres
% Impervious =43.8%
75% Water Quality Volume =14,142 cf
Top of Dam =615.00 ft
Riser =4x4
Riser Elevation =614.15 ft
Orifice =6"x33"
Orifice Elevation =613.00 ft
Top of Media =611.00 ft
Bottom of Media =610.00 ft
Barrel Diameter =39 in
Invert In =609.00 ft
Invert Out =608.00 ft
Length =35 ft
% Slope =2.86%
STORMWATER CONTROL MEASURE 'A' ROUTING RESULTS
Inflow Outflow Max WSE Freeboard
Return Period [cfs][cfs][ft][ft]
WQV 5.26 0.14 612.76 2.24
2-Year 14.60 6.06 614.04 0.96
10-Year 19.76 15.43 614.31 0.69
25-Year 22.69 19.19 614.42 0.58
50-Year 25.03 21.22 614.48 0.52
100-Year 27.02 22.73 614.53 0.47
SUMMARY OF RESULTS
Project Name: Belshire Subdivision Date: 7/17/2019
Project Number: COU-15000 Calculated By: J. Mattingly
DETENTION SUMMARY
Design Drainage Area =8.25 acres
Design Impervious Area =4.78 acres
% Impervious =57.9%
75% Water Quality Volume =12,831 cf
Top of Dam =624.00 ft
Riser =4x4
Riser Elevation =623.00 ft
Top of Media =620.00 ft
Bottom of Media =619.00 ft
Barrel Diameter =24 in
Invert In =615.00 ft
Invert Out =612.00 ft
Length =54 ft
% Slope =5.56%
STORMWATER CONTROL MEASURE 'B' ROUTING RESULTS
Inflow Outflow Max WSE Freeboard
Return Period [cfs][cfs][ft][ft]
WQV 6.30 0.16 622.75 1.25
2-Year 9.36 6.76 623.26 0.74
10-Year 10.80 10.19 623.35 0.65
25-Year 11.62 10.96 623.37 0.63
50-Year 12.24 11.53 623.38 0.62
100-Year 12.79 12.03 623.39 0.61
SUMMARY OF RESULTS
Project Name: Belshire Subdivision Date: 7/18/2019
Project Number: COU-15000 Calculated By: J. Mattingly
DETENTION SUMMARY
Top of Dam =620.00 ft
Riser =6x6
Riser Elevation =618.00 ft
Orifice Size =1.50 in
Orifice Elevation =616.50 ft
Barrel Diameter =48 in
Invert In =611.00 ft
Invert Out =610.00 ft
Length =35 ft
% Slope =2.86%
POND ROUTING RESULTS
Inflow Outflow Max WSE Freeboard
Return Period [cfs][cfs][ft][ft]
WQV 1.32 0.01 616.57 3.43
2-Year 48.33 0.05 617.34 2.66
10-Year 91.81 1.57 618.03 1.97
25-Year 113.60 13.59 618.27 1.73
50-Year 130.29 23.65 618.46 1.54
100-Year 145.37 36.71 618.62 1.38
SUMMARY OF RESULTS
BELSHIRE OF WAXHAW
COU-15000

MISCELLANEOUS SITE INFORMATION

NC Center for Geographic Information & Analysis, Esri, HERE, Garmin, ©
OpenStreetMap contributors
0 750 1,500375
Feet
1 inch = 750 feet
¯BELSHIRE OF WAXHAW
SITE AERIAL MAP
PROJECT #: COU-15000
WAXHAW, NORTH CAROLINA
Copyright:© 2013 National Geographic Society, i-cubed
0 2,000 4,0001,000
Feet
1 inch = 2,000 feet
¯BELSHIRE OF WAXHAW
USGS TOPO MAP
PROJECT #: COU-15000
WAXHAW, NORTH CAROLINA
BELSHIRE OF WAXHAW
COU-15000

WATERSHED SOILS INFORMATION

Hydrologic Soil Group—Union County, North Carolina
(Property Line)
Natural Resources
Conservation Service
Web Soil Survey
National Cooperative Soil Survey
1/26/2019
Page 1 of 4386444038645203864600386468038647603864840386492038650003865080386444038645203864600386468038647603864840386492038650003865080521680521760521840521920522000522080522160
521680 521760 521840 521920 522000 522080 522160
34° 55' 41'' N 80° 45' 45'' W34° 55' 41'' N80° 45' 25'' W34° 55' 19'' N
80° 45' 45'' W34° 55' 19'' N
80° 45' 25'' WN
Map projection: Web Mercator Corner coordinates: WGS84 Edge tics: UTM Zone 17N WGS84
0 150 300 600 900
Feet
0 45 90 180 270
Meters
Map Scale: 1:3,260 if printed on A portrait (8.5" x 11") 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 18, Sep 10, 2018
Soil map units are labeled (as space allows) for map scales
1:50,000 or larger.
Date(s) aerial images were photographed: Jul 18, 2011—Nov
25, 2017
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
1/26/2019
Page 2 of 4
Hydrologic Soil Group
Map unit symbol Map unit name Rating Acres in AOI Percent of AOI
GfB2 Georgeville silty clay
loam, 2 to 8 percent
slopes, moderately
eroded
B 18.1 60.3%
TbC2 Tarrus gravelly silty clay
loam, 8 to 15 percent
slopes, moderately
eroded
B 11.9 39.7%
Totals for Area of Interest 30.0 100.0%
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.
Hydrologic Soil Group—Union County, North Carolina Property Line
Natural Resources
Conservation Service
Web Soil Survey
National Cooperative Soil Survey
1/26/2019
Page 3 of 4
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
1/26/2019
Page 4 of 4
BELSHIRE OF WAXHAW
COU-15000

PRECIPITATION DATA

Storm Data Detailed
Report: Monroe
Element Details
186ID Notes
MonroeLabel
WQV
WQVLabel min1,440.00End Time
years0Return Event in1.750Depth
min0.00Start Time CumulativeStorm Event Depth Type
min6.00Increment
WQV
Depth
(in)
Depth
(in)
Depth
(in)
Depth
(in)
Depth
(in)
Time
(min)
0.0070.0050.0040.0020.0000.00
0.0160.0150.0130.0110.00930.00
0.0260.0240.0220.0200.01860.00
0.0360.0340.0320.0300.02890.00
0.0470.0450.0430.0410.038120.00
0.0580.0560.0540.0510.049150.00
0.0700.0670.0650.0630.060180.00
0.0820.0790.0770.0740.072210.00
0.0940.0920.0890.0860.084240.00
0.1070.1050.1020.0990.097270.00
0.1220.1190.1160.1130.110300.00
0.1370.1340.1310.1280.125330.00
0.1530.1500.1460.1430.140360.00
0.1700.1660.1630.1600.156390.00
0.1880.1840.1800.1770.173420.00
0.2060.2020.1990.1950.191450.00
0.2270.2220.2180.2140.210480.00
0.2520.2460.2410.2360.231510.00
0.2800.2740.2680.2630.257540.00
0.3100.3030.2970.2910.285570.00
0.3480.3400.3320.3240.317600.00
0.3990.3870.3770.3660.357630.00
0.4750.4570.4400.4250.411660.00
0.9940.7540.6200.5370.495690.00
1.2691.2481.2231.1931.160720.00
1.3401.3281.3151.3011.286750.00
1.3901.3811.3711.3611.351780.00
1.4281.4211.4141.4061.398810.00
1.4601.4541.4481.4411.435840.00
1.4881.4831.4771.4721.466870.00
1.5141.5091.5041.4991.494900.00
1.5361.5321.5271.5231.518930.00
1.5561.5521.5481.5441.540960.00
1.5741.5711.5671.5631.560990.00
1.5921.5891.5851.5821.5781,020.00
1.6091.6051.6021.5991.5951,050.00
1.6241.6211.6181.6151.6121,080.00
1.6381.6361.6331.6301.6271,110.00
1.6521.6491.6461.6441.6411,140.00
1.6641.6611.6591.6571.6541,170.00
7/15/2019COU15000.ppc
J. Mattingly, EIBelshire Subdivision
Storm Data Detailed
Report: Monroe
WQV
Depth
(in)
Depth
(in)
Depth
(in)
Depth
(in)
Depth
(in)
Time
(min)
1.6751.6731.6711.6681.6661,200.00
1.6861.6841.6821.6791.6771,230.00
1.6971.6951.6931.6911.6881,260.00
1.7081.7061.7031.7011.6991,290.00
1.7181.7161.7141.7121.7101,320.00
1.7281.7261.7241.7221.7201,350.00
1.7381.7361.7341.7321.7301,380.00
1.7481.7461.7441.7421.7401,410.00
(N/A)(N/A)(N/A)(N/A)1.7501,440.00
1 year
1 yearLabel min5.00Increment
years1Return Event min1,440.00End Time
min0.00Start Time CumulativeStorm Event Depth Type
1 year
Depth
(in)
Depth
(in)
Depth
(in)
Depth
(in)
Depth
(in)
Time
(min)
0.0130.0100.0070.0030.0000.00
0.0300.0270.0230.0200.01725.00
0.0470.0430.0400.0370.03350.00
0.0630.0600.0570.0530.05075.00
0.0800.0770.0730.0700.067100.00
0.0970.0930.0900.0870.083125.00
0.1130.1100.1070.1030.100150.00
0.1300.1270.1230.1200.117175.00
0.1470.1430.1400.1370.133200.00
0.1630.1600.1570.1530.150225.00
0.1800.1770.1730.1700.167250.00
0.1970.1930.1900.1870.183275.00
0.2130.2100.2070.2030.200300.00
0.2300.2270.2230.2200.217325.00
0.2510.2450.2400.2370.233350.00
0.2780.2730.2670.2620.256375.00
0.3050.3000.2940.2890.283400.00
0.3320.3270.3210.3160.310425.00
0.3590.3540.3480.3430.338450.00
0.3860.3810.3750.3700.365475.00
0.4130.4080.4030.3970.392500.00
0.4450.4350.4300.4240.419525.00
0.4930.4840.4740.4640.454550.00
0.5420.5320.5220.5130.503575.00
0.5910.5810.5710.5610.552600.00
0.6370.6280.6190.6100.600625.00
0.7020.6830.6650.6560.647650.00
0.8430.7750.7570.7380.720675.00
1.6861.2561.0460.9780.911700.00
2.1672.0992.0321.9641.896725.00
2.3082.2902.2722.2532.235750.00
2.3732.3632.3542.3452.327775.00
7/15/2019COU15000.ppc
J. Mattingly, EIBelshire Subdivision
Storm Data Detailed
Report: Monroe
1 year
Depth
(in)
Depth
(in)
Depth
(in)
Depth
(in)
Depth
(in)
Time
(min)
2.4192.4102.4002.3912.382800.00
2.4682.4582.4492.4392.429825.00
2.5172.5072.4972.4882.478850.00
2.5652.5562.5462.5362.526875.00
2.5972.5912.5862.5802.575900.00
2.6242.6182.6132.6082.602925.00
2.6512.6452.6402.6352.629950.00
2.6782.6732.6672.6622.656975.00
2.7052.7002.6942.6892.6831,000.00
2.7322.7272.7212.7162.7101,025.00
2.7592.7542.7482.7432.7381,050.00
2.7802.7772.7732.7702.7651,075.00
2.7972.7932.7902.7872.7831,100.00
2.8132.8102.8072.8032.8001,125.00
2.8302.8272.8232.8202.8171,150.00
2.8472.8432.8402.8372.8331,175.00
2.8632.8602.8572.8532.8501,200.00
2.8802.8772.8732.8702.8671,225.00
2.8972.8932.8902.8872.8831,250.00
2.9132.9102.9072.9032.9001,275.00
2.9302.9272.9232.9202.9171,300.00
2.9472.9432.9402.9372.9331,325.00
2.9632.9602.9572.9532.9501,350.00
2.9802.9772.9732.9702.9671,375.00
2.9972.9932.9902.9872.9831,400.00
(N/A)3.0103.0073.0033.0001,425.00
2 year
2 yearLabel min5.00Increment
years2Return Event min1,440.00End Time
min0.00Start Time CumulativeStorm Event Depth Type
2 year
Depth
(in)
Depth
(in)
Depth
(in)
Depth
(in)
Depth
(in)
Time
(min)
0.0160.0120.0080.0040.0000.00
0.0360.0320.0280.0240.02025.00
0.0550.0510.0470.0440.04050.00
0.0750.0710.0670.0630.05975.00
0.0950.0910.0870.0830.079100.00
0.1150.1110.1070.1030.099125.00
0.1350.1310.1270.1230.119150.00
0.1540.1500.1460.1430.139175.00
0.1740.1700.1660.1620.158200.00
0.1940.1900.1860.1820.178225.00
0.2140.2100.2060.2020.198250.00
0.2340.2300.2260.2220.218275.00
0.2530.2490.2450.2410.237300.00
0.2730.2690.2650.2610.257325.00
0.2980.2920.2850.2810.277350.00
7/15/2019COU15000.ppc
J. Mattingly, EIBelshire Subdivision
Storm Data Detailed
Report: Monroe
2 year
Depth
(in)
Depth
(in)
Depth
(in)
Depth
(in)
Depth
(in)
Time
(min)
0.3320.3250.3180.3120.305375.00
0.3650.3580.3520.3450.338400.00
0.3980.3920.3850.3780.372425.00
0.4320.4250.4180.4120.405450.00
0.4650.4580.4520.4450.438475.00
0.4980.4920.4850.4780.472500.00
0.5370.5250.5180.5120.505525.00
0.5950.5830.5720.5600.548550.00
0.6530.6420.6300.6180.607575.00
0.7120.7000.6880.6770.665600.00
0.7680.7570.7460.7350.723625.00
0.8450.8230.8000.7890.778650.00
1.0180.9350.9130.8900.868675.00
2.0281.5181.2681.1851.102700.00
2.6122.5282.4452.3622.278725.00
2.7852.7632.7402.7182.695750.00
2.8632.8522.8412.8302.808775.00
2.9182.9072.8952.8842.873800.00
2.9772.9652.9532.9422.930825.00
3.0353.0233.0123.0002.988850.00
3.0933.0823.0703.0583.047875.00
3.1323.1253.1183.1123.105900.00
3.1653.1583.1523.1453.138925.00
3.1983.1923.1853.1783.172950.00
3.2323.2253.2183.2123.205975.00
3.2653.2583.2523.2453.2381,000.00
3.2983.2923.2853.2783.2721,025.00
3.3323.3253.3183.3123.3051,050.00
3.3573.3533.3493.3453.3381,075.00
3.3773.3733.3693.3653.3611,100.00
3.3963.3933.3893.3853.3811,125.00
3.4163.4123.4083.4043.4001,150.00
3.4363.4323.4283.4243.4201,175.00
3.4563.4523.4483.4443.4401,200.00
3.4763.4723.4683.4643.4601,225.00
3.4953.4913.4883.4843.4801,250.00
3.5153.5113.5073.5033.4991,275.00
3.5353.5313.5273.5233.5191,300.00
3.5553.5513.5473.5433.5391,325.00
3.5753.5713.5673.5633.5591,350.00
3.5943.5903.5863.5833.5791,375.00
3.6143.6103.6063.6023.5981,400.00
(N/A)3.6303.6263.6223.6181,425.00
10 year
10 yearLabel min5.00Increment
years10Return Event min1,440.00End Time
min0.00Start Time CumulativeStorm Event Depth Type
7/15/2019COU15000.ppc
J. Mattingly, EIBelshire Subdivision
Storm Data Detailed
Report: Monroe
10 year
Depth
(in)
Depth
(in)
Depth
(in)
Depth
(in)
Depth
(in)
Time
(min)
0.0240.0180.0120.0060.0000.00
0.0540.0480.0420.0360.03025.00
0.0840.0780.0720.0660.06050.00
0.1130.1080.1020.0960.09075.00
0.1430.1370.1310.1250.119100.00
0.1730.1670.1610.1550.149125.00
0.2030.1970.1910.1850.179150.00
0.2330.2270.2210.2150.209175.00
0.2630.2570.2510.2450.239200.00
0.2930.2870.2810.2750.269225.00
0.3230.3170.3110.3050.299250.00
0.3520.3460.3400.3340.328275.00
0.3820.3760.3700.3640.358300.00
0.4120.4060.4000.3940.388325.00
0.4500.4400.4300.4240.418350.00
0.5010.4910.4810.4710.460375.00
0.5520.5420.5310.5210.511400.00
0.6020.5920.5820.5720.562425.00
0.6530.6430.6330.6230.612450.00
0.7040.6940.6830.6730.663475.00
0.7540.7440.7340.7240.714500.00
0.8120.7950.7850.7750.765525.00
0.8980.8810.8640.8470.829550.00
0.9840.9670.9500.9330.916575.00
1.0711.0531.0361.0191.002600.00
1.1601.1421.1231.1051.088625.00
1.2871.2511.2151.1971.178650.00
1.5591.4301.3941.3581.323675.00
2.9212.2711.9461.8171.688700.00
3.7613.6323.5033.3743.246725.00
4.0333.9983.9623.9263.890750.00
4.1604.1424.1234.1054.069775.00
4.2494.2324.2154.1974.178800.00
4.3364.3184.3014.2844.267825.00
4.4224.4044.3874.3704.353850.00
4.5084.4914.4734.4564.439875.00
4.5664.5554.5454.5354.525900.00
4.6164.6064.5964.5864.576925.00
4.6674.6574.6474.6374.626950.00
4.7184.7084.6974.6874.677975.00
4.7684.7584.7484.7384.7281,000.00
4.8194.8094.7994.7894.7781,025.00
4.8704.8604.8494.8394.8291,050.00
4.9084.9024.8964.8904.8801,075.00
4.9384.9324.9264.9204.9141,100.00
4.9684.9624.9564.9504.9441,125.00
4.9984.9924.9864.9804.9741,150.00
5.0275.0215.0155.0095.0031,175.00
5.0575.0515.0455.0395.0331,200.00
5.0875.0815.0755.0695.0631,225.00
5.1175.1115.1055.0995.0931,250.00
7/15/2019COU15000.ppc
J. Mattingly, EIBelshire Subdivision
Storm Data Detailed
Report: Monroe
10 year
Depth
(in)
Depth
(in)
Depth
(in)
Depth
(in)
Depth
(in)
Time
(min)
5.1475.1415.1355.1295.1231,275.00
5.1775.1715.1655.1595.1531,300.00
5.2075.2015.1955.1895.1831,325.00
5.2365.2305.2245.2185.2131,350.00
5.2665.2605.2545.2485.2421,375.00
5.2965.2905.2845.2785.2721,400.00
(N/A)5.3205.3145.3085.3021,425.00
25 year
25 yearLabel min5.00Increment
years25Return Event min1,440.00End Time
min0.00Start Time CumulativeStorm Event Depth Type
25 year
Depth
(in)
Depth
(in)
Depth
(in)
Depth
(in)
Depth
(in)
Time
(min)
0.0290.0210.0140.0070.0000.00
0.0640.0570.0500.0430.03625.00
0.1000.0930.0860.0790.07250.00
0.1360.1290.1220.1140.10775.00
0.1720.1650.1570.1500.143100.00
0.2070.2000.1930.1860.179125.00
0.2430.2360.2290.2220.215150.00
0.2790.2720.2650.2580.250175.00
0.3150.3080.3000.2930.286200.00
0.3500.3430.3360.3290.322225.00
0.3860.3790.3720.3650.358250.00
0.4220.4150.4080.4010.393275.00
0.4580.4510.4430.4360.429300.00
0.4940.4860.4790.4720.465325.00
0.5400.5280.5150.5080.501350.00
0.6030.5900.5780.5650.553375.00
0.6650.6530.6400.6280.615400.00
0.7280.7150.7030.6900.678425.00
0.7900.7780.7650.7530.740450.00
0.8530.8400.8280.8150.803475.00
0.9150.9030.8900.8780.865500.00
0.9860.9650.9530.9400.928525.00
1.0901.0691.0481.0281.007550.00
1.1941.1731.1531.1321.111575.00
1.2981.2781.2571.2361.215600.00
1.4151.3901.3651.3401.319625.00
1.5781.5341.4901.4651.440650.00
1.9111.7551.7111.6671.623675.00
3.4522.7422.3772.2222.066700.00
4.4394.2844.1283.9733.817725.00
4.7724.7284.6834.6394.595750.00
4.9354.9104.8854.8604.816775.00
5.0525.0315.0104.9854.960800.00
5.1565.1355.1145.0935.073825.00
7/15/2019COU15000.ppc
J. Mattingly, EIBelshire Subdivision
Storm Data Detailed
Report: Monroe
25 year
Depth
(in)
Depth
(in)
Depth
(in)
Depth
(in)
Depth
(in)
Time
(min)
5.2605.2395.2185.1985.177850.00
5.3645.3435.3235.3025.281875.00
5.4355.4235.4105.3985.385900.00
5.4985.4855.4735.4605.448925.00
5.5605.5485.5355.5235.510950.00
5.6235.6105.5985.5855.573975.00
5.6855.6735.6605.6485.6351,000.00
5.7485.7355.7235.7105.6981,025.00
5.8105.7985.7855.7735.7601,050.00
5.8565.8495.8425.8355.8231,075.00
5.8925.8855.8785.8715.8641,100.00
5.9285.9215.9145.9075.8991,125.00
5.9645.9575.9495.9425.9351,150.00
6.0005.9925.9855.9785.9711,175.00
6.0356.0286.0216.0146.0071,200.00
6.0716.0646.0576.0506.0421,225.00
6.1076.1006.0936.0856.0781,250.00
6.1436.1356.1286.1216.1141,275.00
6.1786.1716.1646.1576.1501,300.00
6.2146.2076.2006.1936.1851,325.00
6.2506.2436.2366.2286.2211,350.00
6.2866.2786.2716.2646.2571,375.00
6.3216.3146.3076.3006.2931,400.00
(N/A)6.3506.3436.3366.3291,425.00
50 year
50 yearLabel min5.00Increment
years50Return Event min1,440.00End Time
min0.00Start Time CumulativeStorm Event Depth Type
50 year
Depth
(in)
Depth
(in)
Depth
(in)
Depth
(in)
Depth
(in)
Time
(min)
0.0320.0240.0160.0080.0000.00
0.0730.0650.0570.0490.04125.00
0.1140.1060.0970.0890.08150.00
0.1540.1460.1380.1300.12275.00
0.1950.1870.1790.1710.162100.00
0.2360.2270.2190.2110.203125.00
0.2760.2680.2600.2520.244150.00
0.3170.3090.3010.2920.284175.00
0.3570.3490.3410.3330.325200.00
0.3980.3900.3820.3740.366225.00
0.4390.4310.4220.4140.406250.00
0.4790.4710.4630.4550.447275.00
0.5200.5120.5040.4960.487300.00
0.5610.5520.5440.5360.528325.00
0.6140.6000.5850.5770.569350.00
0.6870.6720.6580.6430.629375.00
0.7600.7450.7310.7160.702400.00
7/15/2019COU15000.ppc
J. Mattingly, EIBelshire Subdivision
Storm Data Detailed
Report: Monroe
50 year
Depth
(in)
Depth
(in)
Depth
(in)
Depth
(in)
Depth
(in)
Time
(min)
0.8330.8180.8040.7890.775425.00
0.9060.8910.8770.8620.847450.00
0.9790.9640.9500.9350.920475.00
1.0521.0371.0231.0080.993500.00
1.1341.1101.0951.0811.066525.00
1.2521.2281.2041.1811.157550.00
1.3701.3461.3231.2991.275575.00
1.4881.4641.4411.4171.393600.00
1.6301.5981.5671.5351.511625.00
1.8271.7761.7251.6931.662650.00
2.2072.0301.9791.9281.878675.00
3.8823.1222.7372.5602.383700.00
4.9734.7974.6204.4434.267725.00
5.3535.3035.2525.2015.150750.00
5.5505.5185.4875.4555.404775.00
5.6925.6695.6455.6135.582800.00
5.8105.7875.7635.7395.716825.00
5.9285.9055.8815.8585.834850.00
6.0466.0235.9995.9765.952875.00
6.1286.1146.0996.0856.070900.00
6.2016.1876.1726.1576.143925.00
6.2746.2606.2456.2306.216950.00
6.3476.3326.3186.3036.289975.00
6.4206.4056.3916.3766.3621,000.00
6.4936.4786.4646.4496.4351,025.00
6.5666.5516.5376.5226.5071,050.00
6.6196.6116.6036.5956.5801,075.00
6.6606.6526.6446.6366.6281,100.00
6.7016.6926.6846.6766.6681,125.00
6.7416.7336.7256.7176.7091,150.00
6.7826.7746.7666.7576.7491,175.00
6.8226.8146.8066.7986.7901,200.00
6.8636.8556.8476.8396.8311,225.00
6.9046.8966.8876.8796.8711,250.00
6.9446.9366.9286.9206.9121,275.00
6.9856.9776.9696.9616.9531,300.00
7.0267.0187.0097.0016.9931,325.00
7.0667.0587.0507.0427.0341,350.00
7.1077.0997.0917.0827.0741,375.00
7.1487.1397.1317.1237.1151,400.00
(N/A)7.1807.1727.1647.1561,425.00
100 year
100 yearLabel min5.00Increment
years100Return Event min1,440.00End Time
min0.00Start Time CumulativeStorm Event Depth Type
100 year
Depth
(in)
Depth
(in)
Depth
(in)
Depth
(in)
Depth
(in)
Time
(min)
7/15/2019COU15000.ppc
J. Mattingly, EIBelshire Subdivision
Storm Data Detailed
Report: Monroe
100 year
Depth
(in)
Depth
(in)
Depth
(in)
Depth
(in)
Depth
(in)
Time
(min)
0.0370.0270.0180.0090.0000.00
0.0830.0730.0640.0550.04625.00
0.1280.1190.1100.1010.09250.00
0.1740.1650.1560.1470.13875.00
0.2200.2110.2020.1930.183100.00
0.2660.2570.2480.2380.229125.00
0.3120.3030.2930.2840.275150.00
0.3580.3480.3390.3300.321175.00
0.4030.3940.3850.3760.367200.00
0.4490.4400.4310.4220.413225.00
0.4950.4860.4770.4680.458250.00
0.5410.5320.5230.5130.504275.00
0.5870.5780.5680.5590.550300.00
0.6330.6230.6140.6050.596325.00
0.6940.6770.6600.6510.642350.00
0.7790.7620.7450.7280.711375.00
0.8630.8460.8290.8130.796400.00
0.9480.9310.9140.8970.880425.00
1.0331.0160.9990.9820.965450.00
1.1181.1011.0841.0671.050475.00
1.2021.1851.1681.1511.134500.00
1.2971.2701.2531.2361.219525.00
1.4321.4051.3781.3511.324550.00
1.5661.5391.5131.4861.459575.00
1.7011.6741.6471.6201.593600.00
1.8681.8301.7931.7551.728625.00
2.0982.0391.9801.9431.905650.00
2.5332.3352.2762.2172.158675.00
4.3313.5313.1262.9282.731700.00
5.5275.3295.1324.9344.736725.00
5.9625.9035.8435.7845.725750.00
6.1936.1556.1186.0806.021775.00
6.3596.3326.3056.2686.230800.00
6.4946.4676.4406.4136.386825.00
6.6286.6016.5746.5486.521850.00
6.7636.7366.7096.6826.655875.00
6.8586.8416.8246.8076.790900.00
6.9436.9266.9096.8926.875925.00
7.0277.0106.9936.9766.959950.00
7.1127.0957.0787.0617.044975.00
7.1977.1807.1637.1467.1291,000.00
7.2817.2647.2487.2317.2141,025.00
7.3667.3497.3327.3157.2981,050.00
7.4287.4187.4097.4007.3831,075.00
7.4737.4647.4557.4467.4371,100.00
7.5197.5107.5017.4927.4831,125.00
7.5657.5567.5477.5387.5281,150.00
7.6117.6027.5937.5837.5741,175.00
7.6577.6487.6387.6297.6201,200.00
7.7037.6937.6847.6757.6661,225.00
7.7487.7397.7307.7217.7121,250.00
7/15/2019COU15000.ppc
J. Mattingly, EIBelshire Subdivision
Storm Data Detailed
Report: Monroe
100 year
Depth
(in)
Depth
(in)
Depth
(in)
Depth
(in)
Depth
(in)
Time
(min)
7.7947.7857.7767.7677.7581,275.00
7.8407.8317.8227.8137.8031,300.00
7.8867.8777.8687.8587.8491,325.00
7.9327.9237.9137.9047.8951,350.00
7.9787.9687.9597.9507.9411,375.00
8.0238.0148.0057.9967.9871,400.00
(N/A)8.0608.0518.0428.0331,425.00
100 year 50 year 25 year 10 year 2 year 1 year
WQVDepth (in)8.750
7.500
6.250
5.000
3.750
2.500
1.250
0.000
Time (min)
1,440.001,296.001,152.001,008.00864.00720.00576.00432.00288.00144.000.00
7/15/2019COU15000.ppc
J. Mattingly, EIBelshire Subdivision
BELSHIRE OF WAXHAW
COU-15000

PRE-DEVELOPMENT HYDROLOGIC
CALCULATIONS

CLIENT
REVISIONS
PROJECT NO.COU-15000
FILENAME
CHECKED BY XXX
DRAWN BY AJB
SCALE
DATE XX. XX. XXXX
N0.DATE
Y:\Projects\COU\COU-15000\Storm\Construction Drawings\Current Drawings\COU15000-Pre.dwg, 2/28/2019 6:43:36 PM, Mattingly, JessicaThe John R. McAdams Company, Inc.
2905 Meridian Parkway
Durham, NC 27713
phone [phone]
fax [phone]
license number: C-0293
www.mcadamsco.com
BELSHIRE OF WAXHAWCONSTRUCTION DRAWINGSPROJECT ADDRESSCITY, STATE, ZIPSHEET
PLAN INFORMATION
QUEEN CITY LAND, LLC.
1515 VENETIAN WAY DRIVE
WAXHAW, NC 28173
PHONE: XXX. XXX. XXXX
FINAL DRAWING - NOT RELEASED FOR CONSTRUCTION
COU15000-PRE
PREHYDROLOGY MAP
1" = 80'
JAA
LK
S1
SUBBASIN #2
AREA = 20.69 AC
POA 1
SUBBASIN #1
AREA = 6.37 AC S3S2
S1S2PROPERTY BOUNDARY
AREA = 30.00 AC
UNANALYZED SUBBASINS
AREA = 0.99 AC
GRAPHIC SCALE
0 40 80 160
1 inch = 80 ft.
Tc PATH
EXISTING POND
REACH #1S3
Tc PA
T
H
UNANALYZED SUBBASIN
AREA = 3.02 AC
01.28.2019
POA 2S1S2Tc PATHREACH
#
2
SUBBASIN #3
AREA = 6.44 AC
POA 3
Project Name: Belshire of Waxhaw Date: 2/28/2019
Project Number: COU-15000 Calculated By: J. Mattingly
INPUT SUMMARY
Total Area
Subbasin ID Impervious Open Wooded Pond Total Impervious Open Wooded Pond Total [acres]SCS CN Tc [min]
1 0.00 0.05 6.31 0.00 6.37 0.00 0.00 0.00 0.00 0.00 6.37 55 16.81
2 0.02 4.46 13.55 1.58 19.62 0.26 0.81 0.00 0.00 1.07 20.69 61 22.70
3 0.00 0.00 0.00 0.00 0.00 0.59 1.49 4.36 0.00 6.44 6.44 60 16.78
Unanalyzed 0.00 0.00 4.01 0.00 4.01 0.00 0.00 0.00 0.00 0.00 4.01 55 -
Totals 0.02 4.51 23.88 1.58 30.00 0.85 2.30 4.36 0.00 7.51 37.51
PRE DEVELOPMENT HYDROLOGIC SUMMARY
Offsite Area [acres]Onsite Area [acres]
Project Name:Belshire of Waxhaw Date:2/28/2019
Project Number:COU-15000 Calculated By:J. Mattingly
Subbasin ID:1
SCS CURVE NUMBER
(REF: TR-55 and NRCS Web Soil Survey).
HSG Impervious Open Wooded Pond
A 98 39 30 100
B 98 61 55 100
C 98 74 70 100
D 98 80 77 100
HSG 'A' =0%
HSG 'B' =100%
HSG 'C' =0%
HSG 'D' =0%
Cover Composite
Condition SCS CN
Impervious 98
Open 61
Wooded 55
Pond 100
WATERSHED BREAKDOWN
Composite Area Area
SCS CN [sf][acres]
98 0 0.00
61 2,258 0.05
55 275,009 6.31
100 0 0.00
98 0 0.00
61 0 0.00
55 0 0.00
100 0 0.00
Total Area =277,267 sf
=6.37 acres
Composite SCS CN =55
% Impervious =0.00%
TIME OF CONCENTRATION
(REF: SCS Segmental Approach, TR-55).
Segment 1: Overland Flow Segment 2: Concentrated Flow
Length =100 ft Length =609 ft
Upstream Elevation =663.00 ft Upstream Elevation =657.50 ft
Downstream Elevation =657.50 ft Downstream Elevation =597.50 ft
Height =5.50 ft Height =60.00 ft
Slope =0.0550 ft/ft Slope =0.0985 ft/ft
Manning's n =0.40 wooded Paved?No
P (2-year/24-hour) =3.12 inches (Waxhaw, NC)Velocity =5.06 ft/sec
Segment Time =14.51 minutes Segment Time =2.00 minutes
Segment 3: Channel Flow
Length =88 ft
Upstream Elevation =597.50 ft
Downstream Elevation =592.43 ft
Height =5.07 ft
Slope =0.0576 ft/ft
Manning's n =0.045 natural channel
Flow Area =2.00 sf (assume 2'x1' channel)
Wetted Perimeter =4.00 lf (assume 2'x1' channel)
Channel Velocity =5.01 ft/sec
Segment Time =0.29 minutes
Time of Concentration =16.81 minutes
SCS Lag Time =10.08 minutes
-
Offsite Pond -
Offsite Impervious -
Offsite Wooded Assume good condition
Offsite Open Assume good condition
PRE DEVELOPMENT HYDROLOGIC CALCULATIONS
Comments
Contributing Area
Onsite Impervious
Onsite Open
Comments
-
Assume good condition
-
Assume good condition
-
Assume good condition
Assume good condition
Onsite Wooded
Onsite Pond
Project Name:Belshire of Waxhaw Date:2/28/2019
Project Number:COU-15000 Calculated By:J. Mattingly
Subbasin ID:2
SCS CURVE NUMBER
(REF: TR-55 and NRCS Web Soil Survey).
HSG Impervious Open Wooded Pond
A 98 39 30 100
B 98 61 55 100
C 98 74 70 100
D 98 80 77 100
HSG 'A' =0%
HSG 'B' =100%
HSG 'C' =0%
HSG 'D' =0%
Cover Composite
Condition SCS CN
Impervious 98
Open 61
Wooded 55
Pond 100
WATERSHED BREAKDOWN
Composite Area Area
SCS CN [sf][acres]
98 1,068 0.02
61 194,384 4.46
55 590,445 13.55
100 68,776 1.58
98 11,263 0.26
61 35,221 0.81
55 0 0.00
100 0 0.00
Total Area =901,157 sf
=20.69 acres
Composite SCS CN =61
% Impervious =3.91%
TIME OF CONCENTRATION
(REF: SCS Segmental Approach, TR-55).
Segment 1: Overland Flow Segment 2: Concentrated Flow
Length =100 ft Length =319 ft
Upstream Elevation =657.00 ft Upstream Elevation =655.00 ft
Downstream Elevation =655.00 ft Downstream Elevation =617.00 ft
Height =2.00 ft Height =38.00 ft
Slope =0.0200 ft/ft Slope =0.1191 ft/ft
Manning's n =0.40 wooded Paved?No
P (2-year/24-hour) =3.12 inches (Waxhaw, NC)Velocity =5.57 ft/sec
Segment Time =21.75 minutes Segment Time =0.95 minutes
Time of Concentration =22.70 minutes
SCS Lag Time =13.62 minutes
Offsite Wooded Assume good condition
Offsite Pond -
Offsite Open Assume good condition
Onsite Wooded Assume good condition
Onsite Pond -
Offsite Impervious -
Contributing Area Comments
Onsite Impervious -
Onsite Open Assume good condition
-
PRE DEVELOPMENT HYDROLOGIC CALCULATIONS
Comments
-
Assume good condition
Assume good condition
Project Name:Belshire of Waxhaw Date:2/28/2019
Project Number:COU-15000 Calculated By:J. Mattingly
Subbasin ID:3
SCS CURVE NUMBER
(REF: TR-55 and NRCS Web Soil Survey).
HSG Impervious Open Wooded Pond
A 98 39 30 100
B 98 61 55 100
C 98 74 70 100
D 98 80 77 100
HSG 'A' =0%
HSG 'B' =100%
HSG 'C' =0%
HSG 'D' =0%
Cover Composite
Condition SCS CN
Impervious 98
Open 61
Wooded 55
Pond 100
WATERSHED BREAKDOWN
Composite Area Area
SCS CN [sf][acres]
98 0 0.00
61 0 0.00
55 0 0.00
100 0 0.00
98 25,622 0.59
61 65,029 1.49
55 189,904 4.36
100 0 0.00
Total Area =280,555 sf
=6.44 acres
Composite SCS CN =60
% Impervious =24.20%
TIME OF CONCENTRATION
(REF: SCS Segmental Approach, TR-55).
Segment 1: Overland Flow Segment 2: Concentrated Flow
Length =100 ft Length =313 ft
Upstream Elevation =668.00 ft Upstream Elevation =663.00 ft
Downstream Elevation =663.00 ft Downstream Elevation =638.00 ft
Height =5.00 ft Height =25.00 ft
Slope =0.0500 ft/ft Slope =0.0799 ft/ft
Manning's n =0.40 wooded Paved?No
P (2-year/24-hour) =3.12 inches (Waxhaw, NC)Velocity =4.56 ft/sec
Segment Time =15.07 minutes Segment Time =1.14 minutes
Segment 3: Channel Flow
Length =141 ft
Upstream Elevation =638.00 ft
Downstream Elevation =631.00 ft
Height =7.00 ft
Slope =0.0496 ft/ft
Manning's n =0.045 natural channel
Flow Area =1.50 sf (assume 1.5'x1' channel)
Wetted Perimeter =3.50 lf (assume 1.5'x1' channel)
Channel Velocity =4.19 ft/sec
Segment Time =0.56 minutes
Time of Concentration =16.78 minutes
SCS Lag Time =10.07 minutes
-
PRE 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:Belshire of Waxhaw Date:2/28/2019
Project Number:COU-15000 Calculated By:J. Mattingly
Subbasin ID:Unanalyzed
SCS CURVE NUMBER
(REF: TR-55 and NRCS Web Soil Survey).
HSG Impervious Open Wooded Pond
A 98 39 30 100
B 98 61 55 100
C 98 74 70 100
D 98 80 77 100
HSG 'A' =0%
HSG 'B' =100%
HSG 'C' =0%
HSG 'D' =0%
Cover Composite
Condition SCS CN
Impervious 98
Open 61
Wooded 55
Pond 100
WATERSHED BREAKDOWN
Composite Area Area
SCS CN [sf][acres]
98 0 0.00
61 0 0.00
55 174,881 4.01
100 0 0.00
98 0 0.00
61 0 0.00
55 0 0.00
100 0 0.00
Total Area =174,881 sf
=4.01 acres
Composite SCS CN =55
% Impervious =0.00%
-
PRE 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 Wooded Assume good condition
Offsite Pond -
Offsite Open Assume good condition
Project Name:Belshire of Waxhaw Date:2/28/2019
Project Number:COU-15000 Calculated By:J. Mattingly
Subbasin ID:Reach
REACH 1: POA 2 to POA 1
(REF: SCS Segmental Approach, TR-55).
Length =255 ft
Upstream Elevation =602.99 ft
Downstream Elevation =592.43 ft
Height =10.56 ft
Slope =0.0414 ft/ft
Manning's n =0.045 natural channel
Flow Area =4.00 sf (assume 2'x2' channel)
Wetted Perimeter =6.00 lf (assume 2'x2' channel)
Channel Velocity =5.14 ft/sec
Segment Time =0.83 minutes
Time of Concentration =0.83 minutes
SCS Lag Time =0.50 minutes
REACH 2: POA 3 to POA 2
(REF: SCS Segmental Approach, TR-55).
Length =289 ft
Upstream Elevation =631.00 ft
Downstream Elevation =617.00 ft
Height =14.00 ft
Slope =0.0484 ft/ft
Manning's n =0.045 natural channel
Flow Area =1.50 sf (assume 1.5'x1' channel)
Wetted Perimeter =3.50 lf (assume 1.5'x1' channel)
Channel Velocity =4.14 ft/sec
Segment Time =1.16 minutes
Time of Concentration =1.16 minutes
SCS Lag Time =0.70 minutes
PRE DEVELOPMENT HYDROLOGIC CALCULATIONS
Scenario: Pre 2-year
Reach2Reach 12/28/2019COU15000-WQ.ppc
J. Mattingly, EIBelshire Subdivision
Subsection: Master Network Summary
Catchments Summary
Peak Flow
(ft³/s)
Time to Peak
(min)
Hydrograph
Volume
(ft³)
Return
Event
(years)
ScenarioLabel
1.32735.008,945.0002Pre 2-year1
5.80731.0026,249.00010Pre 10-year1
9.01730.5039,579.00025Pre 25-year1
14.13730.5064,942.000100Pre 100-year1
8.78735.5046,981.0002Pre 2-year2
24.79735.50116,541.00010Pre 10-year2
35.03732.50167,153.00025Pre 25-year2
51.21732.50260,267.000100Pre 100-year2
2.90731.5013,646.0002Pre 2-year3
8.56729.5034,649.00010Pre 10-year3
12.19729.5050,059.00025Pre 25-year3
17.77729.5078,552.000100Pre 100-year3
Node Summary
Peak Flow
(ft³/s)
Time to Peak
(min)
Hydrograph
Volume
(ft³)
Return
Event
(years)
ScenarioLabel
12.83736.5069,528.0002Pre 2-yearPOA 1
38.67733.50177,349.00010Pre 10-yearPOA 1
55.47733.50256,671.00025Pre 25-yearPOA 1
81.60733.50403,591.000100Pre 100-yearPOA 1
11.53735.5060,619.0002Pre 2-yearPOA 2
33.10732.50151,173.00010Pre 10-yearPOA 2
46.99732.50217,189.00025Pre 25-yearPOA 2
68.50732.50338,787.000100Pre 100-yearPOA 2
2.90731.5013,646.0002Pre 2-yearPOA 3
8.56729.5034,649.00010Pre 10-yearPOA 3
12.19729.5050,059.00025Pre 25-yearPOA 3
17.77729.5078,552.000100Pre 100-yearPOA 3
7/1/2019COU15000.ppc
J. Mattingly, EIBelshire Subdivision
BELSHIRE OF WAXHAW
COU-15000

POST-DEVELOPMENT HYDROLOGIC
CALCULATIONS

CLIENT
REVISIONS
PROJECT NO.COU-15000
FILENAME
CHECKED BY MVD
DRAWN BY AJB
SCALE
DATE 04. 17. 2019
N0.DATE
Y:\Projects\COU\COU-15000\Storm\Construction Drawings\Current Drawings\COU15000-Post.dwg, 7/18/2019 9:53:03 AM, Mattingly, JessicaThe John R. McAdams Company, Inc.
www.mcadamsco.com
3430 Toringdon Way
Suite 110
phone [phone]
fax [phone]
license number: C-0293
Charlotte, NC 28277
BELSHIRE OF WAXHAWCONSTRUCTION DRAWINGS4401 HELMS ROADWAXHAW, NORTH CAROLINA, 28173SHEET
PLAN INFORMATION
BROADSTREET HOMES
1312 CAMP CREEK ROAD
LANCASTER, SC 29720
FINAL DRAWING - NOT RELEASED FOR CONSTRUCTION
1 07. 18. 2019 1ST ROUND OF COMMENTS
COU15000-POST
POSTHYDROLOGY MAP
1" = 80'
JAA
JSM
S1
SUBBASIN #2-To SB A
AREA = 9.94 AC
POA 1
SUBBASIN #1
AREA = 2.84 AC S3S2
S1S2PROPERTY BOUNDARY
AREA = 30.00 AC
UNANALYZED SUBBASINS
AREA = 0.92 AC
GRAPHIC SCALE
0 40 80 160
1 inch = 80 ft.
Tc PATH
POND
REACH #1UNANALYZED SUBBASIN
AREA = 1.39 AC
POA 2 REACH #2SUBBASIN #3
AREA = 7.38 AC
POA 3
SUBBASIN #2-To Pond
AREA = 5.04 AC
SUBBASIN #2-To SB B
AREA = 7.63 AC
SUBBASIN #2-To SCM A
AREA = 1.75 AC
SUBBASIN #2-To SCM B
AREA = 0.62 AC
S1
S
2
Tc

P
A
T
H
SPLITTER BOX B
SPLITTER BOX A
Project Name:Belshire of Waxhaw Date:7/15/2019
Project Number:COU-15000 Calculated By:J. Mattingly
INPUT SUMMARY
Total Area
Subbasin ID Impervious Open Wooded Pond Total Impervious Open Wooded Pond Total [acres]SCS CN Tc [min]
1 0.10 0.98 1.75 0.00 2.84 0.00 0.00 0.00 0.00 0.00 2.84 59 11.65
2-To SB A 4.06 4.64 0.10 0.00 8.80 0.46 0.69 0.00 0.00 1.15 9.94 78 5.00
2-To SCM A 0.61 1.07 0.07 0.00 1.75 0.00 0.00 0.00 0.00 0.00 1.75 74 5.00
2-To SB B 4.51 3.12 0.00 0.00 7.63 0.00 0.00 0.00 0.00 0.00 7.63 83 5.00
2-To SCM B 0.26 0.35 0.00 0.00 0.62 0.00 0.00 0.00 0.00 0.00 0.62 77 5.00
2-To Pond 0.35 1.44 1.80 1.44 5.04 0.00 0.00 0.00 0.00 0.00 5.04 73 5.00
3 0.02 0.46 0.54 0.00 1.02 0.57 1.43 4.36 0.00 6.36 7.38 60 15.50
Unanalyzed 0.01 0.31 1.99 0.00 2.31 0.00 0.00 0.00 0.00 0.00 2.31 56 -
Totals 9.92 12.37 6.26 1.44 30.00 1.03 2.12 4.36 0.00 7.51 37.51
POST DEVELOPMENT HYDROLOGIC SUMMARY
Offsite Area [acres]Onsite Area [acres]
Project Name:Belshire of Waxhaw Date:7/15/2019
Project Number:COU-15000 Calculated By:J. Mattingly
Subbasin ID:1
SCS CURVE NUMBER
(REF: TR-55 and NRCS Web Soil Survey).
HSG Impervious Open Wooded Pond
A 98 39 30 100
B 98 61 55 100
C 98 74 70 100
D 98 80 77 100
HSG 'A' =0%
HSG 'B' =100%
HSG 'C' =0%
HSG 'D' =0%
Cover Composite
Condition SCS CN
Impervious 98
Open 61
Wooded 55
Pond 100
WATERSHED BREAKDOWN
Composite Area Area
SCS CN [sf][acres]
98 4,523 0.10
61 42,767 0.98
55 76,275 1.75
100 0 0.00
98 0 0.00
61 0 0.00
55 0 0.00
100 0 0.00
Total Area =123,565 sf
=2.84 acres
Composite SCS CN =59
% Impervious =3.66%
TIME OF CONCENTRATION
(REF: SCS Segmental Approach, TR-55).
Segment 1: Overland Flow Segment 2: Concentrated Flow
Length =100 ft Length =76 ft
Upstream Elevation =647.00 ft Upstream Elevation =637.00 ft
Downstream Elevation =637.00 ft Downstream Elevation =628.00 ft
Height =10.00 ft Height =9.00 ft
Slope =0.1000 ft/ft Slope =0.1184 ft/ft
Manning's n =0.40 wooded Paved?No
P (2-year/24-hour) =3.12 inches (Waxhaw, NC)Velocity =5.55 ft/sec
Segment Time =11.42 minutes Segment Time =0.23 minutes
Time of Concentration =11.65 minutes
SCS Lag Time =6.99 minutes
POST DEVELOPMENT HYDROLOGIC CALCULATIONS
Comments
Contributing Area
Onsite Impervious
Onsite Open
Comments
-
Assume good condition
-
Assume good condition
-
Assume good condition
Assume good condition
Onsite Wooded
Onsite Pond -
Offsite Pond -
Offsite Impervious -
Offsite Wooded Assume good condition
Offsite Open Assume good condition
Project Name:Belshire of Waxhaw Date:7/15/2019
Project Number:COU-15000 Calculated By:J. Mattingly
Subbasin ID:2 To SB A
SCS CURVE NUMBER
(REF: TR-55 and NRCS Web Soil Survey).
HSG Impervious Open Wooded Pond
A 98 39 30 100
B 98 61 55 100
C 98 74 70 100
D 98 80 77 100
HSG 'A' =0%
HSG 'B' =100%
HSG 'C' =0%
HSG 'D' =0%
Cover Composite
Condition SCS CN
Impervious 98
Open 61
Wooded 55
Pond 100
WATERSHED BREAKDOWN
Composite Area Area
SCS CN [sf][acres]
98 176,760 4.06
61 202,230 4.64
55 4,194 0.10
100 0 0.00
98 19,885 0.46
61 30,076 0.69
55 0 0.00
100 0 0.00
Total Area =433,145 sf
=9.94 acres
Composite SCS CN =78
% Impervious =49.91%
TIME OF CONCENTRATION
(REF: SCS Segmental Approach, TR-55).
Time of Concentration =5.00 minutes
SCS Lag Time =3.00 minutes
-
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 Wooded Assume good condition
Offsite Pond -
Offsite Open Assume good condition
Project Name:Belshire of Waxhaw Date:7/15/2019
Project Number:COU-15000 Calculated By:J. Mattingly
Subbasin ID:2 To SCM A
SCS CURVE NUMBER
(REF: TR-55 and NRCS Web Soil Survey).
HSG Impervious Open Wooded Pond
A 98 39 30 100
B 98 61 55 100
C 98 74 70 100
D 98 80 77 100
HSG 'A' =0%
HSG 'B' =100%
HSG 'C' =0%
HSG 'D' =0%
Cover Composite
Condition SCS CN
Impervious 98
Open 61
Wooded 55
Pond 100
WATERSHED BREAKDOWN
Composite Area Area
SCS CN [sf][acres]
98 26,457 0.61
61 46,721 1.07
55 3,145 0.07
100 0 0.00
98 0 0.00
61 0 0.00
55 0 0.00
100 0 0.00
Total Area =76,323 sf
=1.75 acres
Composite SCS CN =74
% Impervious =34.66%
TIME OF CONCENTRATION
(REF: SCS Segmental Approach, TR-55).
Time of Concentration =5.00 minutes
SCS Lag Time =3.00 minutes
-
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 Wooded Assume good condition
Offsite Pond -
Offsite Open Assume good condition
Project Name:Belshire of Waxhaw Date:7/15/2019
Project Number:COU-15000 Calculated By:J. Mattingly
Subbasin ID:2 To SB B
SCS CURVE NUMBER
(REF: TR-55 and NRCS Web Soil Survey).
HSG Impervious Open Wooded Pond
A 98 39 30 100
B 98 61 55 100
C 98 74 70 100
D 98 80 77 100
HSG 'A' =0%
HSG 'B' =100%
HSG 'C' =0%
HSG 'D' =0%
Cover Composite
Condition SCS CN
Impervious 98
Open 61
Wooded 55
Pond 100
WATERSHED BREAKDOWN
Composite Area Area
SCS CN [sf][acres]
98 196,608 4.51
61 135,833 3.12
55 0 0.00
100 0 0.00
98 0 0.00
61 0 0.00
55 0 0.00
100 0 0.00
Total Area =332,441 sf
=7.63 acres
Composite SCS CN =83
% Impervious =59.14%
TIME OF CONCENTRATION
(REF: SCS Segmental Approach, TR-55).
Time of Concentration =5.00 minutes
SCS Lag Time =3.00 minutes
-
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 Wooded Assume good condition
Offsite Pond -
Offsite Open Assume good condition
Project Name:Belshire of Waxhaw Date:7/15/2019
Project Number:COU-15000 Calculated By:J. Mattingly
Subbasin ID:2 To SCM B
SCS CURVE NUMBER
(REF: TR-55 and NRCS Web Soil Survey).
HSG Impervious Open Wooded Pond
A 98 39 30 100
B 98 61 55 100
C 98 74 70 100
D 98 80 77 100
HSG 'A' =0%
HSG 'B' =100%
HSG 'C' =0%
HSG 'D' =0%
Cover Composite
Condition SCS CN
Impervious 98
Open 61
Wooded 55
Pond 100
WATERSHED BREAKDOWN
Composite Area Area
SCS CN [sf][acres]
98 11,537 0.26
61 15,376 0.35
55 0 0.00
100 0 0.00
98 0 0.00
61 0 0.00
55 0 0.00
100 0 0.00
Total Area =26,913 sf
=0.62 acres
Composite SCS CN =77
% Impervious =42.87%
TIME OF CONCENTRATION
(REF: SCS Segmental Approach, TR-55).
Time of Concentration =5.00 minutes
SCS Lag Time =3.00 minutes
-
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 Wooded Assume good condition
Offsite Pond -
Offsite Open Assume good condition
Project Name:Belshire of Waxhaw Date:7/15/2019
Project Number:COU-15000 Calculated By:J. Mattingly
Subbasin ID:2 To Pond
SCS CURVE NUMBER
(REF: TR-55 and NRCS Web Soil Survey).
HSG Impervious Open Wooded Pond
A 98 39 30 100
B 98 61 55 100
C 98 74 70 100
D 98 80 77 100
HSG 'A' =0%
HSG 'B' =100%
HSG 'C' =0%
HSG 'D' =0%
Cover Composite
Condition SCS CN
Impervious 98
Open 61
Wooded 55
Pond 100
WATERSHED BREAKDOWN
Composite Area Area
SCS CN [sf][acres]
98 15,318 0.35
61 62,545 1.44
55 78,595 1.80
100 62,913 1.44
98 0 0.00
61 0 0.00
55 0 0.00
100 0 0.00
Total Area =219,371 sf
=5.04 acres
Composite SCS CN =73
% Impervious =6.98%
TIME OF CONCENTRATION
(REF: SCS Segmental Approach, TR-55).
Time of Concentration =5.00 minutes
SCS Lag Time =3.00 minutes
-
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:Belshire of Waxhaw Date:7/15/2019
Project Number:COU-15000 Calculated By:J. Mattingly
Subbasin ID:3
SCS CURVE NUMBER
(REF: TR-55 and NRCS Web Soil Survey).
HSG Impervious Open Wooded Pond
A 98 39 30 100
B 98 61 55 100
C 98 74 70 100
D 98 80 77 100
HSG 'A' =0%
HSG 'B' =100%
HSG 'C' =0%
HSG 'D' =0%
Cover Composite
Condition SCS CN
Impervious 98
Open 61
Wooded 55
Pond 100
WATERSHED BREAKDOWN
Composite Area Area
SCS CN [sf][acres]
98 712 0.02
61 20,057 0.46
55 23,692 0.54
100 0 0.00
98 24,818 0.57
61 62,356 1.43
55 189,904 4.36
100 0 0.00
Total Area =321,539 sf
=7.38 acres
Composite SCS CN =60
% Impervious =20.55%
TIME OF CONCENTRATION
(REF: SCS Segmental Approach, TR-55).
Segment 1: Overland Flow Segment 2: Concentrated Flow
Length =100 ft Length =178 ft
Upstream Elevation =668.00 ft Upstream Elevation =663.00 ft
Downstream Elevation =663.00 ft Downstream Elevation =630.00 ft
Height =5.00 ft Height =33.00 ft
Slope =0.0500 ft/ft Slope =0.1854 ft/ft
Manning's n =0.40 wooded Paved?No
P (2-year/24-hour) =3.12 inches (Waxhaw, NC)Velocity =6.95 ft/sec
Segment Time =15.07 minutes Segment Time =0.43 minutes
Time of Concentration =15.50 minutes
SCS Lag Time =9.30 minutes
-
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 Wooded Assume good condition
Offsite Pond -
Offsite Open Assume good condition
Project Name:Belshire of Waxhaw Date:7/15/2019
Project Number:COU-15000 Calculated By:J. Mattingly
Subbasin ID:Unanalyzed
SCS CURVE NUMBER
(REF: TR-55 and NRCS Web Soil Survey).
HSG Impervious Open Wooded Pond
A 98 39 30 100
B 98 61 55 100
C 98 74 70 100
D 98 80 77 100
HSG 'A' =0%
HSG 'B' =100%
HSG 'C' =0%
HSG 'D' =0%
Cover Composite
Condition SCS CN
Impervious 98
Open 61
Wooded 55
Pond 100
WATERSHED BREAKDOWN
Composite Area Area
SCS CN [sf][acres]
98 264 0.01
61 13,407 0.31
55 86,897 1.99
100 0 0.00
98 0 0.00
61 0 0.00
55 0 0.00
100 0 0.00
Total Area =100,568 sf
=2.31 acres
Composite SCS CN =56
% Impervious =0.26%
Offsite Wooded Assume good condition
Offsite Pond -
Offsite Open Assume good condition
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:Belshire of Waxhaw Date:3/6/2019
Project Number:COU-15000 Calculated By:J. Mattingly
Subbasin ID:Reach
REACH 1: POA 2 to POA 1
(REF: SCS Segmental Approach, TR-55).
Length =299 ft
Upstream Elevation =610.00 ft
Downstream Elevation =592.43 ft
Height =17.57 ft
Slope =0.0588 ft/ft
Manning's n =0.045 natural channel
Flow Area =4.00 sf (assume 2'x2' channel)
Wetted Perimeter =6.00 lf (assume 2'x2' channel)
Channel Velocity =6.13 ft/sec
Segment Time =0.81 minutes
Time of Concentration =0.81 minutes
SCS Lag Time =0.49 minutes
REACH 2: POA 3 to POA 2
(REF: SCS Segmental Approach, TR-55).
Length =229 ft
Upstream Elevation =630.00 ft
Downstream Elevation =621.00 ft
Height =9.00 ft
Slope =0.0393 ft/ft
Manning's n =0.013 RCP
Flow Area =1.77 sf (assume 18" RCP)
Wetted Perimeter =4.71 lf (assume 18" RCP)
Channel Velocity =11.82 ft/sec
Segment Time =0.32 minutes
Time of Concentration =0.32 minutes
SCS Lag Time =0.19 minutes
POST DEVELOPMENT HYDROLOGIC CALCULATIONS
Scenario: Post WQV
Reach3Reach 17/15/2019COU15000.ppc
J. Mattingly, EIBelshire Subdivision
Subsection: Master Network Summary
Catchments Summary
Peak Flow
(ft³/s)
Time to Peak
(min)
Hydrograph
Volume
(ft³)
Return
Event
(years)
ScenarioLabel
1.363728.505,597.0002Post 2-year1
4.191727.0014,569.00010Post 10-year1
5.962727.0021,209.00025Post 25-year1
8.730725.5033,551.000100Post 100-year1
4.014721.508,437.0002Post 2-year2-To SCM A
7.145721.5016,632.00010Post 10-year2-To SCM A
8.746721.5022,085.00025Post 25-year2-To SCM A
11.081721.0031,591.000100Post 100-year2-To SCM A
28.101721.5057,530.0002Post 2-year2-To SB A
46.440721.50107,572.00010Post 10-year2-To SB A
55.465721.50140,171.00025Post 25-year2-To SB A
68.502721.00196,284.000100Post 100-year2-To SB A
26.967721.5054,445.0002Post 2-year2-To SB B
41.180721.0095,851.00010Post 10-year2-To SB B
47.929721.00122,202.00025Post 25-year2-To SB B
57.447721.00166,954.000100Post 100-year2-To SB B
3.467731.5015,647.0002Post 2-year3
10.260729.5039,727.00010Post 10-year3
14.506729.5057,393.00025Post 25-year3
21.006729.5090,056.000100Post 100-year3
1.668721.503,433.0002Post 2-year2-To SCM B
2.805721.506,502.00010Post 10-year2-To SCM B
3.370721.508,511.00025Post 25-year2-To SCM B
4.188721.0011,980.000100Post 100-year2-To SCM B
10.913721.5023,156.0002Post 2-year2-To Pond
19.836721.5046,291.00010Post 10-year2-To Pond
24.443721.5061,774.00025Post 25-year2-To Pond
31.182721.0088,856.000100Post 100-year2-To Pond
Node Summary
Peak Flow
(ft³/s)
Time to Peak
(min)
Hydrograph
Volume
(ft³)
Return
Event
(years)
ScenarioLabel
12.818751.5089,712.0002Post 2-yearPOA 1
29.386726.00198,549.00010Post 10-yearPOA 1
35.762724.50304,210.00025Post 25-yearPOA 1
61.519752.00489,194.000100Post 100-yearPOA 1
0.0521,440.002,065.0002Post 2-yearPOA 2
1.572901.5033,248.00010Post 10-yearPOA 2
13.591754.5088,878.00025Post 25-yearPOA 2
36.712752.50184,244.000100Post 100-yearPOA 2
3.467731.5015,647.0002Post 2-yearPOA 3
10.260729.5039,727.00010Post 10-yearPOA 3
14.506729.5057,393.00025Post 25-yearPOA 3
21.006729.5090,056.000100Post 100-yearPOA 3
Pond Summary
7/18/2019COU15000.ppc
J. Mattingly, EIBelshire Subdivision
Subsection: Master Network Summary
Pond Summary
Maximum
Pond Storage
(ft³)
Maximum
Water
Surface
Elevation
(ft)
Peak Flow
(ft³/s)
Time to Peak
(min)
Hydrograph
Volume
(ft³)
Return
Event
(years)
ScenarioLabel
(N/A)(N/A)48.333722.0059,633.0002Post 2-yearPOND (IN)
57,568.000617.340.0521,440.002,065.0002Post 2-yearPOND (OUT)
(N/A)(N/A)91.809721.50140,398.00010Post 10-yearPOND (IN)
108,681.000618.031.572901.5033,248.00010Post 10-yearPOND (OUT)
(N/A)(N/A)113.596721.50196,326.00025Post 25-yearPOND (IN)
128,037.000618.2713.591754.5088,878.00025Post 25-yearPOND (OUT)
(N/A)(N/A)145.373721.50292,200.000100Post 100-yearPOND (IN)
157,123.000618.6236.712752.50184,244.000100Post 100-yearPOND (OUT)
(N/A)(N/A)14.604721.5056,119.0002Post 2-yearSCM A (IN)
17,398.000614.046.063753.0045,826.0002Post 2-yearSCM A
(OUT)
(N/A)(N/A)19.756721.5097,210.00010Post 10-yearSCM A (IN)
19,650.000614.3115.431726.5086,617.00010Post 10-yearSCM A
(OUT)
(N/A)(N/A)22.691721.50123,285.00025Post 25-yearSCM A (IN)
20,517.000614.4219.186724.50112,481.00025Post 25-yearSCM A
(OUT)
(N/A)(N/A)27.016721.50169,180.000100Post 100-yearSCM A (IN)
21,404.000614.5322.727724.00158,099.000100Post 100-yearSCM A
(OUT)
(N/A)(N/A)9.357721.0046,874.0002Post 2-yearSCM B (IN)
12,263.000623.266.761730.0036,227.0002Post 2-yearSCM B
(OUT)
(N/A)(N/A)10.796721.5074,929.00010Post 10-yearSCM B (IN)
12,772.000623.3510.190723.5064,152.00010Post 10-yearSCM B
(OUT)
(N/A)(N/A)11.620721.5092,482.00025Post 25-yearSCM B (IN)
12,879.000623.3710.963723.5081,689.00025Post 25-yearSCM B
(OUT)
(N/A)(N/A)12.786721.50124,284.000100Post 100-yearSCM B (IN)
13,026.000623.3912.027723.00113,367.000100Post 100-yearSCM B
(OUT)
(N/A)(N/A)28.101721.5057,530.0002Post 2-yearSB A (IN)
38.000627.1927.949722.0057,521.0002Post 2-yearSB A (OUT)
(N/A)(N/A)46.440721.50107,572.00010Post 10-yearSB A (IN)
50.000628.4346.359721.50107,558.00010Post 10-yearSB A (OUT)
(N/A)(N/A)55.465721.50140,171.00025Post 25-yearSB A (IN)
59.000629.3755.423721.50140,155.00025Post 25-yearSB A (OUT)
(N/A)(N/A)68.502721.00196,284.000100Post 100-yearSB A (IN)
77.000631.0768.411721.50196,263.000100Post 100-yearSB A (OUT)
(N/A)(N/A)26.967721.5054,445.0002Post 2-yearSB B (IN)
46.000627.7826.889721.5054,436.0002Post 2-yearSB B (OUT)
(N/A)(N/A)41.180721.0095,851.00010Post 10-yearSB B (IN)
56.000628.6341.170721.5095,838.00010Post 10-yearSB B (OUT)
(N/A)(N/A)47.929721.00122,202.00025Post 25-yearSB B (IN)
60.000628.9947.885721.50122,188.00025Post 25-yearSB B (OUT)
(N/A)(N/A)57.447721.00166,954.000100Post 100-yearSB B (IN)
66.000629.5157.340721.50166,936.000100Post 100-yearSB B (OUT)
7/18/2019COU15000.ppc
J. Mattingly, EIBelshire Subdivision
BELSHIRE OF WAXHAW
COU-15000

DESIGN OF STORMWATER CONTROL MEASURE
‘A’

Project Name:Belshire Date:7/15/2019
Project Number:COU-15000 Calculated By:J. Mattingly, EI
Facility ID:SCM 'A'
SAND FILTER
Average Incremental Accumulated Calculated
Contour Stage Contour Area Contour Area Contour Vol Contour Vol Stage
[ft][ft][sf][sf][cf][cf][ft]
611.00 0.00 1,554
612.00 1.00 2,037 1,796 1,796 1,796 1.00
612.50 1.50 2,300 2,169 1,084 2,880 1.49
613.00 2.00 2,577 2,439 1,219 4,099 2.01
b =1.1892
Ks =1790
STAGE-STORAGE FUNCTION - SAND FILTER 'A'
y = 1790.4x1.1892
R² = 0.9998
0
500
1,000
1,500
2,000
2,500
3,000
3,500
4,000
4,500
0.00 0.50 1.00 1.50 2.00 2.50Storage (CF)Stage (feet)
Storage vs. Stage
Project Name:Belshire Date:7/17/2019
Project Number:COU-15000 Calculated By:J. Mattingly, EI
Facility ID:SCM 'A'
PRE-TREATMENT
Average Incremental Accumulated Calculated
Contour Stage Contour Area Contour Area Contour Vol Contour Vol Stage
[ft][ft][sf][sf][cf][cf][ft]
611.00 0.00 1,994
612.00 1.00 3,128 2,561 2,561 2,561 1.00
612.50 1.50 3,513 3,321 1,660 4,221 1.50
613.00 2.00 3,921 3,717 1,859 6,080 2.00
b =1.2463
Ks =2557
STAGE-STORAGE FUNCTION - PRE-TREATMENT 'A'
y = 2556.8x1.2463
R² = 0.9999
0
1,000
2,000
3,000
4,000
5,000
6,000
7,000
0.00 0.50 1.00 1.50 2.00 2.50Storage (CF)Stage (feet)
Storage vs. Stage
Project Name:Belshire Date:7/17/2019
Project Number:COU-15000 Calculated By:J. Mattingly, EI
Facility ID:SCM 'A'
TOTAL STORAGE ABOVE SAND FILTER
Average Incremental Accumulated Calculated
Contour Stage Contour Area Contour Area Contour Vol Contour Vol Stage
[ft][ft][sf][sf][cf][cf][ft]
611.00 0.00 3,548
612.00 1.00 5,165 4,357 4,357 4,357 1.01
612.50 1.50 5,813 5,489 2,745 7,101 1.49
613.00 2.00 6,498 6,156 3,078 10,179 1.97
614.00 3.00 7,658 7,078 7,078 17,257 2.99
615.00 4.00 8,753 8,206 8,206 25,462 4.05
b =1.2742
Ks =4281
STAGE-STORAGE FUNCTION - TOTAL 'A'
y = 4281.3x1.2742
R² = 0.9995
0
5,000
10,000
15,000
20,000
25,000
30,000
0.00 1.00 2.00 3.00 4.00 5.00Storage (CF)Stage (feet)
Storage vs. Stage
Project Name:Belshire Date:7/15/2019
Project Number:COU-15000 Calculated By:J. Mattingly, EI
Facility ID:SCM 'A'
DETERMINATION OF WATER QUALITY VOLUME
(REF: Simple Method, Schueler, 1987).
WQV = P x Rv x A / 12
where,
WQV = Water Quality Volume (acre-ft)
Rv = 0.05 + 0.009 x I, where I is % Impervious Cover
A = Area (acres)
P = Rainfall (inches)
Total Drainage Area, A =11.70 acres
Total Impervious Area =5.12 acres
% Impervious, I =43.8%
Rainfall, P =1.00 inches
Rv =0.44 acres
WQV =0.43 acre-ft
18,855 cf
SAND FILTER SIZING
AF = [(WQV)(dF)]/[(k)(hA+ dF)(t)]
where,
AF = surface area of filter bed (sf)
WQV= water quality volume (cf)
dF = filter bed depth (feet)
k = coefficient of permeability of filter media (ft/day)
hA = average height of water above filter bed (feet)
t = design filter bed drain time (days)
75% of WQV =14,142 cf
dF =1.50 ft (1.5' minimum per design)
k =0.02 gal/min/sf (assumed at 0.02 gal/min/sf)
=3.50 ft/day (assume 1 sf of filter media)
hA =1.00 ft (1 foot maximum)
t =2.000 days
AF =1,212 sf (minimum sand filter area required)
AP =1,554 sf (sand filter area provided)
WATER QUALITY VOLUME CALCULATION
UNDERDRAIN SIZING
(REF: Charlotte-Mecklenburg BMP Design Manual).
Compute drawdown through filter bed
Q = A(k)(hF+dF)/(dF)
where,
A = provided surface area of filter bed (sf)
k = coefficient of permeability of filter media (ft/day)
hF = height of water above filter bed (feet)
dF = filter bed depth (feet)
A =1,554 sf
k =3.50 ft/day
hF =2.00 ft
dF =1.50 ft
Q =12,691 cf/day
=0.147 cfs
Compute minimum drawdown discharge
WQV =18,855 cf
t =2.000 days
Minimum drawdown, Q =0.109 cfs
Compute underdrain pipe capacity
Number of rows, n =2
Diameter of underdrains, d =6 inches
Area, A =0.196 sf
Wetted perimeter, P =1.571 ft
Slope, S =0.005 ft/ft
Capacity of one pipe =0.395 cfs
Total capacity =0.790 cfs
Assume 50% clogging =0.395 cfs DESIGN ACCEPTABLE
Compute underdrain preforation capacity
3/8-inch perforations spaced 3 inches on center, along 4 longitudinal rows spaced 90 o apart
Number of rows, n =2
Diameter of underdrains, d =6 inches
Length of underdrains, L =70 ft
Number of perforations =2,240 holes
Capacity of one hole =0.008 cfs
Total capacity =18.498 cfs
Assume 50% clogging =9.249 cfs DESIGN ACCEPTABLE
STAGE-DISCHARGE FOR SAND MEDIA
(REF: Charlotte-Mecklenburg BMP Design Manual).
AF = [(WQV)(dF)]/[(k)(hA+ dF)(t)]
WQV / t = QO = AF (k)(hF+ dF)/(dF)
A =1,554 sf
dF =1.50 ft
Surface of sand media =611.00 ft
k =3.50 ft/day
Elevation Height hF Discharge Qo
[ft][ft][cfs]
611.00 0.00 0.063
611.50 0.50 0.084
612.00 1.00 0.105
612.50 1.50 0.126
613.00 2.00 0.147
613.50 2.50 0.168
614.00 3.00 0.189
614.50 3.50 0.210
615.00 4.00 0.231
Storm Event: WQVLabel: SCM A
Return Event: 0 yearsSubsection: Elevation-Area Volume Curve
Volume (Total)
(ft³)
Volume
(ft³)
A1+A2+sqr
(A1*A2)
(ft²)
Area
(ft²)
Planimeter
(ft²)
Elevation
(ft)
0.0000.0000.003,548.000.000611.00
4,306.0004,306.00012,918.805,112.000.000612.00
7,020.0002,714.00016,285.095,751.000.000612.50
10,061.0003,041.00018,244.356,418.000.000613.00
17,090.0007,029.00021,086.647,658.000.000614.00
25,289.0008,199.00024,598.218,753.000.000615.00
7/17/2019COU15000.ppc
J. Mattingly, EIBelshire Subdivision
Storm Event: WQVLabel: SCM A
Return Event: 0 yearsSubsection: Outlet Input Data
Requested Pond Water Surface Elevations
ft611.00Minimum (Headwater)
ft0.50Increment (Headwater)
ft615.00Maximum (Headwater)
Outlet Connectivity
E2
(ft)
E1
(ft)
OutfallDirectionOutlet IDStructure Type
615.00613.00CulvertForwardOrificeOrifice-Area
615.00614.05CulvertForwardRiserInlet Box
615.000.00CulvertForwardMediaUser Defined
Table
615.00609.00TWForwardCulvertCulvert-Circular
(N/A)(N/A)TailwaterTailwater Settings
7/17/2019COU15000.ppc
J. Mattingly, EIBelshire Subdivision
Storm Event: WQVLabel: SCM A
Return Event: 0 yearsSubsection: Outlet Input Data
Structure ID: Culvert
Structure Type: Culvert-Circular
1Number of Barrels
in24.0Diameter
ft39.00Length
ft39.01Length (Computed Barrel)
ft/ft0.026Slope (Computed)
Outlet Control Data
0.013Manning's n
0.50Ke
0.01Kb
0.00Kr
ft0.00Convergence Tolerance
Inlet Control Data
Form 1Equation Form
0.0098K
2.0000M
0.0398C
0.6700Y
1.15T1 ratio (HW/D)
1.29T2 ratio (HW/D)
-0.50Slope Correction Factor
Use unsubmerged inlet control 0 equation below T1 elevation.
Use submerged inlet control 0 equation above T2 elevation
In transition zone between unsubmerged and submerged inlet
control,
interpolate between flows at T1 & T2...
ft611.29T1 Elevation ft³/s15.550T1 Flow
ft611.59T2 Elevation ft³/s17.772T2 Flow
7/17/2019COU15000.ppc
J. Mattingly, EIBelshire Subdivision
Storm Event: WQVLabel: SCM A
Return Event: 0 yearsSubsection: Outlet Input Data
Structure ID: Media
Structure Type: User Defined Table
Flow
(ft³/s)
Elevation
(ft)
0.063611.00
0.084611.50
0.105612.00
0.126612.50
0.147613.00
0.168613.50
0.189614.00
0.210614.50
0.231615.00
Structure ID: Riser
Structure Type: Inlet Box
1Number of Openings
ft614.05Elevation
ft²16.000Orifice Area
0.60Orifice Coefficient
ft16.00Weir Length
(ft^0.5)/s3.00Weir Coefficient
1.00K Reverse
0.00Manning's n
0.00Kev, Charged Riser
FalseWeir Submergence
FalseOrifice H to crest
Structure ID: Orifice
Structure Type: Orifice-Area
1Number of Openings
ft613.00Elevation
ft²1.375Orifice Area
ft613.50Top Elevation
ft613.25Datum Elevation
0.60Orifice Coefficient
Structure ID: TW
Structure Type: TW Setup, DS Channel
Free OutfallTailwater Type
Convergence Tolerances
30Maximum Iterations
ft0.01Tailwater Tolerance
(Minimum)
ft0.50Tailwater Tolerance
(Maximum)
ft0.01Headwater Tolerance
(Minimum)
7/17/2019COU15000.ppc
J. Mattingly, EIBelshire Subdivision
Storm Event: WQVLabel: SCM A
Return Event: 0 yearsSubsection: Outlet Input Data
Convergence Tolerances
ft0.50Headwater Tolerance
(Maximum)
ft³/s0.001Flow Tolerance (Minimum)
ft³/s10.000Flow Tolerance (Maximum)
7/17/2019COU15000.ppc
J. Mattingly, EIBelshire Subdivision
Storm Event: WQVLabel: SCM A
Return Event: 0 yearsSubsection: Composite Rating Curve
Composite Outflow Summary
Contributing StructuresConvergence Error
(ft)
Tailwater Elevation
(ft)
Flow
(ft³/s)
Water Surface
Elevation
(ft)
Media,Culvert (no Q:
Orifice,Riser)
0.00(N/A)0.064611.00
Media,Culvert (no Q:
Orifice,Riser)
0.00(N/A)0.084611.50
Media,Culvert (no Q:
Orifice,Riser)
0.00(N/A)0.104612.00
Media,Culvert (no Q:
Orifice,Riser)
0.00(N/A)0.126612.50
Media,Culvert (no Q:
Orifice,Riser)
0.00(N/A)0.147613.00
Orifice,Media,Culvert (no
Q: Riser)
0.00(N/A)3.477613.50
Orifice,Media,Culvert (no
Q: Riser)
0.00(N/A)5.916614.00
Orifice,Media,Culvert (no
Q: Riser)
0.00(N/A)6.111614.05
Orifice,Riser,Media,Culvert
0.00(N/A)22.101614.50
Riser,Media,Culvert (no
Q: Orifice)
0.00(N/A)34.088615.00
7/17/2019COU15000.ppc
J. Mattingly, EIBelshire Subdivision
Storm Event: WQVLabel: SB A
Return Event: 0 yearsSubsection: Interconnected Pond Routing Summary
Infiltration
No InfiltrationInfiltration Method
(Computed)
Initial Conditions Calculation Tolerances
ft623.42Elevation (Starting Water
Surface Computed)
ft³/s0.000Flow Tolerance (Minimum)
ft³0.000Volume (Starting) 35Maximum Iterations
ft³/s0.000Outflow (Starting) min3.00ICPM Time Step
15.000624.91720.50
Volume
(ft³)
Elevation
(ft)
Time to
Peak
(min)
Maximum Storage
0.0000.19
0.000698.00
Flow (Peak)
(ft³/s)
Time to Peak
(min)
Reverse Flow Peaks
4.730720.50Pond Outflow...
4.739720.50Pond Inflow....
Flow (Peak)
(ft³/s)
Time to Peak
(min)
Forward Flow Peaks
Forward12,640.000
Reverse0.000
DirectionVolume
(ft³)
Total Volume Out
Reverse0.000Pond Outflow...
Forward12,643.000Pond Inflow....
DirectionVolume
(ft³)
Total Volume In
Mass Balance (ft³)
ft³0.000Volume (Initial ICPM)
ft³12,643.000Volume (Total In ICPM)
ft³12,640.000Volume (Total Out ICPM)
ft³2.000Volume (Ending)
ft623.60Elevation (Ending)
ft³1.000Difference
%0.0
Percent of Inflow Volume
(Interconnected Pond Mass
Balance)
7/17/2019COU15000.ppc
J. Mattingly, EIBelshire Subdivision
Storm Event: WQVLabel: SCM A
Return Event: 0 yearsSubsection: Interconnected Pond Routing Summary
Infiltration
No InfiltrationInfiltration Method
(Computed)
Initial Conditions Calculation Tolerances
ft611.00Elevation (Starting Water
Surface Computed)
ft³/s0.000Flow Tolerance (Minimum)
ft³0.000Volume (Starting) 35Maximum Iterations
ft³/s0.064Outflow (Starting) min3.00ICPM Time Step
8,629.000612.761,168.50
Volume
(ft³)
Elevation
(ft)
Time to
Peak
(min)
Maximum Storage
0.0000.00
0.0000.00
Flow (Peak)
(ft³/s)
Time to Peak
(min)
Reverse Flow Peaks
0.1371,173.00Pond Outflow...
5.257720.50Pond Inflow....
Flow (Peak)
(ft³/s)
Time to Peak
(min)
Forward Flow Peaks
Forward5,806.000
Reverse0.000
DirectionVolume
(ft³)
Total Volume Out
Reverse0.000Pond Outflow...
Forward14,164.000Pond Inflow....
DirectionVolume
(ft³)
Total Volume In
Mass Balance (ft³)
ft³0.000Volume (Initial ICPM)
ft³14,164.000Volume (Total In ICPM)
ft³5,806.000Volume (Total Out ICPM)
ft³8,369.000Volume (Ending)
ft612.72Elevation (Ending)
ft³-12.000Difference
%0.1
Percent of Inflow Volume
(Interconnected Pond Mass
Balance)
7/17/2019COU15000.ppc
J. Mattingly, EIBelshire Subdivision
Storm Event: 2 yearLabel: SCM A
Return Event: 2 yearsSubsection: Interconnected Pond Routing Summary
Infiltration
No InfiltrationInfiltration Method
(Computed)
Initial Conditions Calculation Tolerances
ft611.00Elevation (Starting Water
Surface Computed)
ft³/s0.000Flow Tolerance (Minimum)
ft³0.000Volume (Starting) 35Maximum Iterations
ft³/s0.064Outflow (Starting) min3.00ICPM Time Step
17,398.000614.04753.00
Volume
(ft³)
Elevation
(ft)
Time to
Peak
(min)
Maximum Storage
0.0000.00
0.0000.00
Flow (Peak)
(ft³/s)
Time to Peak
(min)
Reverse Flow Peaks
6.063753.00Pond Outflow...
14.604721.50Pond Inflow....
Flow (Peak)
(ft³/s)
Time to Peak
(min)
Forward Flow Peaks
Forward45,826.000
Reverse0.000
DirectionVolume
(ft³)
Total Volume Out
Reverse0.000Pond Outflow...
Forward56,119.000Pond Inflow....
DirectionVolume
(ft³)
Total Volume In
Mass Balance (ft³)
ft³0.000Volume (Initial ICPM)
ft³56,119.000Volume (Total In ICPM)
ft³45,826.000Volume (Total Out ICPM)
ft³10,357.000Volume (Ending)
ft613.04Elevation (Ending)
ft³-64.000Difference
%0.1
Percent of Inflow Volume
(Interconnected Pond Mass
Balance)
7/17/2019COU15000.ppc
J. Mattingly, EIBelshire Subdivision
Storm Event: 10 yearLabel: SCM A
Return Event: 10 yearsSubsection: Interconnected Pond Routing Summary
Infiltration
No InfiltrationInfiltration Method
(Computed)
Initial Conditions Calculation Tolerances
ft611.00Elevation (Starting Water
Surface Computed)
ft³/s0.000Flow Tolerance (Minimum)
ft³0.000Volume (Starting) 35Maximum Iterations
ft³/s0.064Outflow (Starting) min3.00ICPM Time Step
19,650.000614.31726.50
Volume
(ft³)
Elevation
(ft)
Time to
Peak
(min)
Maximum Storage
0.0000.00
0.0000.00
Flow (Peak)
(ft³/s)
Time to Peak
(min)
Reverse Flow Peaks
15.431726.50Pond Outflow...
19.756721.50Pond Inflow....
Flow (Peak)
(ft³/s)
Time to Peak
(min)
Forward Flow Peaks
Forward86,617.000
Reverse0.000
DirectionVolume
(ft³)
Total Volume Out
Reverse0.000Pond Outflow...
Forward97,210.000Pond Inflow....
DirectionVolume
(ft³)
Total Volume In
Mass Balance (ft³)
ft³0.000Volume (Initial ICPM)
ft³97,210.000Volume (Total In ICPM)
ft³86,617.000Volume (Total Out ICPM)
ft³10,670.000Volume (Ending)
ft613.09Elevation (Ending)
ft³-77.000Difference
%0.1
Percent of Inflow Volume
(Interconnected Pond Mass
Balance)
7/17/2019COU15000.ppc
J. Mattingly, EIBelshire Subdivision
Storm Event: 25 yearLabel: SCM A
Return Event: 25 yearsSubsection: Interconnected Pond Routing Summary
Infiltration
No InfiltrationInfiltration Method
(Computed)
Initial Conditions Calculation Tolerances
ft611.00Elevation (Starting Water
Surface Computed)
ft³/s0.000Flow Tolerance (Minimum)
ft³0.000Volume (Starting) 35Maximum Iterations
ft³/s0.064Outflow (Starting) min3.00ICPM Time Step
20,517.000614.42724.50
Volume
(ft³)
Elevation
(ft)
Time to
Peak
(min)
Maximum Storage
0.0000.00
0.0000.00
Flow (Peak)
(ft³/s)
Time to Peak
(min)
Reverse Flow Peaks
19.186724.50Pond Outflow...
22.691721.50Pond Inflow....
Flow (Peak)
(ft³/s)
Time to Peak
(min)
Forward Flow Peaks
Forward112,481.000
Reverse0.000
DirectionVolume
(ft³)
Total Volume Out
Reverse0.000Pond Outflow...
Forward123,285.000Pond Inflow....
DirectionVolume
(ft³)
Total Volume In
Mass Balance (ft³)
ft³0.000Volume (Initial ICPM)
ft³123,285.000Volume (Total In ICPM)
ft³112,481.000Volume (Total Out ICPM)
ft³10,853.000Volume (Ending)
ft613.11Elevation (Ending)
ft³-49.000Difference
%0.0
Percent of Inflow Volume
(Interconnected Pond Mass
Balance)
7/17/2019COU15000.ppc
J. Mattingly, EIBelshire Subdivision
Storm Event: 50 yearLabel: SCM A
Return Event: 50 yearsSubsection: Interconnected Pond Routing Summary
Infiltration
No InfiltrationInfiltration Method
(Computed)
Initial Conditions Calculation Tolerances
ft611.00Elevation (Starting Water
Surface Computed)
ft³/s0.000Flow Tolerance (Minimum)
ft³0.000Volume (Starting) 35Maximum Iterations
ft³/s0.064Outflow (Starting) min3.00ICPM Time Step
20,985.000614.48724.00
Volume
(ft³)
Elevation
(ft)
Time to
Peak
(min)
Maximum Storage
0.0000.00
0.0000.00
Flow (Peak)
(ft³/s)
Time to Peak
(min)
Reverse Flow Peaks
21.216724.00Pond Outflow...
25.034721.50Pond Inflow....
Flow (Peak)
(ft³/s)
Time to Peak
(min)
Forward Flow Peaks
Forward122,260.000
Reverse0.000
DirectionVolume
(ft³)
Total Volume Out
Reverse0.000Pond Outflow...
Forward130,552.000Pond Inflow....
DirectionVolume
(ft³)
Total Volume In
Mass Balance (ft³)
ft³0.000Volume (Initial ICPM)
ft³130,552.000Volume (Total In ICPM)
ft³122,260.000Volume (Total Out ICPM)
ft³8,360.000Volume (Ending)
ft612.72Elevation (Ending)
ft³-68.000Difference
%0.1
Percent of Inflow Volume
(Interconnected Pond Mass
Balance)
7/17/2019COU15000.ppc
J. Mattingly, EIBelshire Subdivision
Storm Event: 100 yearLabel: SCM A
Return Event: 100 yearsSubsection: Interconnected Pond Routing Summary
Infiltration
No InfiltrationInfiltration Method
(Computed)
Initial Conditions Calculation Tolerances
ft611.00Elevation (Starting Water
Surface Computed)
ft³/s0.000Flow Tolerance (Minimum)
ft³0.000Volume (Starting) 35Maximum Iterations
ft³/s0.064Outflow (Starting) min3.00ICPM Time Step
21,404.000614.53724.00
Volume
(ft³)
Elevation
(ft)
Time to
Peak
(min)
Maximum Storage
0.0000.00
0.0000.00
Flow (Peak)
(ft³/s)
Time to Peak
(min)
Reverse Flow Peaks
22.727724.00Pond Outflow...
27.016721.50Pond Inflow....
Flow (Peak)
(ft³/s)
Time to Peak
(min)
Forward Flow Peaks
Forward158,099.000
Reverse0.000
DirectionVolume
(ft³)
Total Volume Out
Reverse0.000Pond Outflow...
Forward169,180.000Pond Inflow....
DirectionVolume
(ft³)
Total Volume In
Mass Balance (ft³)
ft³0.000Volume (Initial ICPM)
ft³169,180.000Volume (Total In ICPM)
ft³158,099.000Volume (Total Out ICPM)
ft³11,165.000Volume (Ending)
ft613.16Elevation (Ending)
ft³-84.000Difference
%0.0
Percent of Inflow Volume
(Interconnected Pond Mass
Balance)
7/17/2019COU15000.ppc
J. Mattingly, EIBelshire Subdivision
Project Name:Belshire Date:7/16/2019
Project Number:COU-15000 Calculated By:J. Mattingly
Facility ID:SCM A
INPUT DATA
Inside Length =4.00 ft
Inside Width =4.00 ft
Wall Thickness =6.00 in
Standard Base Length =5.00 ft
Standard Base Width =5.00 ft
Standard Base Thickness =6.00 in
Inside Height of Riser =4.88 ft
Concrete Unit Weight =142.00 pcf Unit weight of manhole concrete is 142 pcf per NC Products
Outside Diameter of Barrel =30.00 in
Drain Pipe (if present) =6.00 in
TRASH RACK DISPLACEMENT
Bottom Length / Width =8.40 ft Calculation for truncated square pyramid
Top Length / Width =2.10 ft
Height =2.00 ft
Trash Rack Displacement =61.740 cf
CONCRETE PRESENT IN RISER STRUCTURE
Riser Walls =43.920 cf
Standard Base of Riser =12.500 cf
Less Opening for Barrel =2.454 cf
Less Opening for Drain Pipe =0.098 cf
Less Opening for Orifice =4.500 cf
Total Concrete Less Openings =49.367 cf
Weight of Concrete =7,010 lbs
AMOUNT OF WATER DISPLACED BY RISER STRUCTURE
Displacement by Concrete =49.367 cf
Displacement by Open Air =78.080 cf
Displacement by Trash Rack =61.740 cf
Total Water Displaced =189.187 cf
Weight of Water Displaced =11,805 lbs
RISER ANTI-FLOTATION CALCULATION
AMOUNT OF CONCRETE TO ADD TO RISER STRUCTURE
Safety Factor =1.15 Recommend 1.15 or higher
Add'l Weight for Bouyancy =6,566 lbs
Bouyant Weight of Concrete =79.60 pcf
Bouyant Weight w/ SF =69.22 pcf
Add'l Concrete to Add =94.859 cf
Less Standard Base =12.500 cf
New Base Design Required =107.359 cf
ANTI FLOTATION BLOCK DESIGN CALCULATIONS
AF Block Length =8.00 ft
AF Block Width =8.00 ft
AF Block Thickness =24.00 in
AF Block Provided =128.000 cf
Total Concrete Present =169.367 cf
Total Concrete Present =24,050 lbs
Project Name: Belshire of Waxhaw Date: 7/17/2019
Project Number: COU-15000 Calculated By:Jessica Mattingly, EI
Facility ID: SCM A
DESIGN OF RIPRAP OUTLET PROTECTION
Calculations based on NY DOT method - Pages 8.06.05 through 8.06.06 in NC Erosion Control Manual.
Flow, Q10-yr =15.43 cfs
Slope =2.86 %
Pipe Diameter, Do =24 in
=2.00 feet
Number of pipes =1
Pipe separation =0.00 feet
Manning's n =0.013
Zone from graph above =2
Outlet pipe diameter =24 in Length =12.00 ft
Outlet flowrate =15.43 cfs Width =6.00 ft
Outlet velocity =11.55 ft/sec Stone diameter =6.00 in
Material =Class B Thickness =22.00 in
Zone Material Diameter Thickness Length Width
1 Class A 3 9 4 x Do 3 x Do
2 Class B 6 22 6 x Do 3 x Do
3 Class I 13 22 8 x Do 3 x Do
4 Class I 13 22 8 x Do 3 x Do
5 Class II 23 27 10 x Do 3 x Do
6 Class II 23 27 10 x Do 3 x Do
7 Study Required
RIPRAP OUTLET PROTECTION
11.55 ft/sec
0
5
10
15
20
25
0 1 2 3 4 5 6 7 8 9 10Velocity (ft/sec)Pipe diameter (ft)
Figure 8.06.b.1
Zone 1
Zone 2
Zone 3
Zone 4
Zone 5
Zone 6 Zone 7
BELSHIRE OF WAXHAW
COU-15000

DESIGN OF STORMWATER CONTROL MEASURE
‘B’

Project Name:Belshire Date:4/4/2019
Project Number:COU-15000 Calculated By:J. Mattingly, EI
Facility ID:SCM 'B'
SAND FILTER
Average Incremental Accumulated Calculated
Contour Stage Contour Area Contour Area Contour Vol Contour Vol Stage
[ft][ft][sf][sf][cf][cf][ft]
620.00 0.00 1,356
621.00 1.00 1,852 1,604 1,604 1,604 1.01
622.00 2.00 2,412 2,132 2,132 3,736 1.97
622.50 2.50 2,716 2,564 1,282 5,018 2.49
623.00 3.00 3,031 2,874 1,437 6,455 3.04
b =1.2594
Ks =1591
STAGE-STORAGE FUNCTION - SAND FILTER 'B'
y = 1591.1x1.2594
R² = 0.9993
0
1,000
2,000
3,000
4,000
5,000
6,000
7,000
0.00 0.50 1.00 1.50 2.00 2.50 3.00 3.50Storage (CF)Stage (feet)
Storage vs. Stage
Project Name:Belshire Date:4/4/2019
Project Number:COU-15000 Calculated By:J. Mattingly, EI
Facility ID:SCM 'B'
PRE-TREATMENT
Average Incremental Accumulated Calculated
Contour Stage Contour Area Contour Area Contour Vol Contour Vol Stage
[ft][ft][sf][sf][cf][cf][ft]
620.00 0.00 212
621.00 1.00 1,264 738 738 738 1.00
622.00 2.00 1,771 1,518 1,518 2,256 2.00
622.50 2.50 2,056 1,914 957 3,212 2.50
623.00 3.00 2,347 2,202 1,101 4,313 3.00
b =1.6065
Ks =739
STAGE-STORAGE FUNCTION - PRE-TREATMENT 'B'
y = 738.55x1.6065
R² = 1
0
500
1,000
1,500
2,000
2,500
3,000
3,500
4,000
4,500
5,000
0.00 0.50 1.00 1.50 2.00 2.50 3.00 3.50Storage (CF)Stage (feet)
Storage vs. Stage
Project Name:Belshire Date:4/4/2019
Project Number:COU-15000 Calculated By:J. Mattingly, EI
Facility ID:SCM 'B'
TOTAL STORAGE ABOVE SAND FILTER
Average Incremental Accumulated Calculated
Contour Stage Contour Area Contour Area Contour Vol Contour Vol Stage
[ft][ft][sf][sf][cf][cf][ft]
620.00 0.00 1,568
621.00 1.00 3,116 2,342 2,342 2,342 1.01
622.00 2.00 4,183 3,650 3,650 5,992 1.97
622.50 2.50 4,772 4,478 2,239 8,230 2.47
623.00 3.00 5,378 5,075 2,538 10,768 2.99
624.00 4.00 6,430 5,904 5,904 16,672 4.07
b =1.4094
Ks =2302
STAGE-STORAGE FUNCTION - TOTAL 'B'
y = 2302x1.4094
R² = 0.9992
0
2,000
4,000
6,000
8,000
10,000
12,000
14,000
16,000
18,000
0.00 1.00 2.00 3.00 4.00 5.00Storage (CF)Stage (feet)
Storage vs. Stage
Project Name:Belshire Date:7/15/2019
Project Number:COU-15000 Calculated By:J. Mattingly, EI
Facility ID:SCM 'B'
DETERMINATION OF WATER QUALITY VOLUME
(REF: Simple Method, Schueler, 1987).
WQV = P x Rv x A / 12
where,
WQV = Water Quality Volume (acre-ft)
Rv = 0.05 + 0.009 x I, where I is % Impervious Cover
A = Area (acres)
P = Rainfall (inches)
Total Drainage Area, A =8.25 acres
Total Impervious Area =4.78 acres
% Impervious, I =57.9%
Rainfall, P =1.00 inches
Rv =0.57 acres
WQV =0.39 acre-ft
17,108 cf
SAND FILTER SIZING
AF = [(WQV)(dF)]/[(k)(hA+ dF)(t)]
where,
AF = surface area of filter bed (sf)
WQV= water quality volume (cf)
dF = filter bed depth (feet)
k = coefficient of permeability of filter media (ft/day)
hA = average height of water above filter bed (feet)
t = design filter bed drain time (days)
75% of WQV =12,831 cf
dF =1.50 ft (1.5' minimum per design)
k =0.02 gal/min/sf (assumed at 0.02 gal/min/sf)
=3.50 ft/day (assume 1 sf of filter media)
hA =1.00 ft (1 foot maximum)
t =2.000 days
AF =1,100 sf (minimum sand filter area required)
AP =1,356 sf (sand filter area provided)
WATER QUALITY VOLUME CALCULATION
UNDERDRAIN SIZING
(REF: Charlotte-Mecklenburg BMP Design Manual).
Compute drawdown through filter bed
Q = A(k)(hF+dF)/(dF)
where,
A = provided surface area of filter bed (sf)
k = coefficient of permeability of filter media (ft/day)
hF = height of water above filter bed (feet)
dF = filter bed depth (feet)
A =1,356 sf
k =3.50 ft/day
hF =2.00 ft
dF =1.50 ft
Q =11,074 cf/day
=0.128 cfs
Compute minimum drawdown discharge
WQV =17,108 cf
t =2.000 days
Minimum drawdown, Q =0.099 cfs
Compute underdrain pipe capacity
Number of rows, n =1
Diameter of underdrains, d =6 inches
Area, A =0.196 sf
Wetted perimeter, P =1.571 ft
Slope, S =0.005 ft/ft
Capacity of one pipe =0.395 cfs
Total capacity =0.395 cfs
Assume 50% clogging =0.198 cfs DESIGN ACCEPTABLE
Compute underdrain preforation capacity
3/8-inch perforations spaced 3 inches on center, along 4 longitudinal rows spaced 90 o apart
Number of rows, n =1
Diameter of underdrains, d =6 inches
Length of underdrains, L =40 ft
Number of perforations =640 holes
Capacity of one hole =0.008 cfs
Total capacity =5.285 cfs
Assume 50% clogging =2.643 cfs DESIGN ACCEPTABLE
STAGE-DISCHARGE FOR SAND MEDIA
(REF: Charlotte-Mecklenburg BMP Design Manual).
AF = [(WQV)(dF)]/[(k)(hA+ dF)(t)]
WQV / t = QO = AF (k)(hF+ dF)/(dF)
A =1,356 sf
dF =1.50 ft
Surface of sand media =620.00 ft
k =3.50 ft/day
Elevation Height hF Discharge Qo
[ft][ft][cfs]
620.00 0.00 0.055
620.50 0.50 0.073
621.00 1.00 0.092
621.50 1.50 0.110
622.00 2.00 0.128
622.50 2.50 0.146
623.00 3.00 0.165
623.50 3.50 0.183
624.00 4.00 0.201
Storm Event: WQVLabel: SCM B
Return Event: 0 yearsSubsection: Elevation-Area Volume Curve
Volume (Total)
(ft³)
Volume
(ft³)
A1+A2+sqr
(A1*A2)
(ft²)
Area
(ft²)
Planimeter
(ft²)
Elevation
(ft)
0.0000.0000.001,568.000.0620.00
2,298.0002,298.0006,894.403,116.000.0621.00
5,935.0003,636.00010,909.294,183.000.0622.00
8,172.0002,237.00013,422.804,772.000.0622.50
10,708.0002,536.00015,215.955,378.000.0623.00
16,604.0005,896.00017,688.526,430.000.0624.00
4/4/2019COU15000-WQ.ppc
J. Mattingly, EIBelshire Subdivision
Storm Event: WQVLabel: SCM B
Return Event: 0 yearsSubsection: Outlet Input Data
Requested Pond Water Surface Elevations
ft620.00Minimum (Headwater)
ft0.10Increment (Headwater)
ft624.00Maximum (Headwater)
Outlet Connectivity
E2
(ft)
E1
(ft)
OutfallDirectionOutlet IDStructure Type
624.00623.00CulvertForwardRiserInlet Box
624.000.00CulvertForwardMediaUser Defined
Table
624.00615.00TWForwardCulvertCulvert-Circular
(N/A)(N/A)TailwaterTailwater Settings
7/17/2019COU15000.ppc
J. Mattingly, EIBelshire Subdivision
Storm Event: WQVLabel: SCM B
Return Event: 0 yearsSubsection: Outlet Input Data
Structure ID: Culvert
Structure Type: Culvert-Circular
1Number of Barrels
in24.0Diameter
ft40.00Length
ft40.11Length (Computed Barrel)
ft/ft0.075Slope (Computed)
Outlet Control Data
0.013Manning's n
0.50Ke
0.01Kb
0.00Kr
ft0.00Convergence Tolerance
Inlet Control Data
Form 1Equation Form
0.0098K
2.0000M
0.0398C
0.6700Y
1.12T1 ratio (HW/D)
1.27T2 ratio (HW/D)
-0.50Slope Correction Factor
Use unsubmerged inlet control 0 equation below T1 elevation.
Use submerged inlet control 0 equation above T2 elevation
In transition zone between unsubmerged and submerged inlet
control,
interpolate between flows at T1 & T2...
ft617.25T1 Elevation ft³/s15.550T1 Flow
ft617.54T2 Elevation ft³/s17.772T2 Flow
7/17/2019COU15000.ppc
J. Mattingly, EIBelshire Subdivision
Storm Event: WQVLabel: SCM B
Return Event: 0 yearsSubsection: Outlet Input Data
Structure ID: Riser
Structure Type: Inlet Box
1Number of Openings
ft623.00Elevation
ft²16.000Orifice Area
0.60Orifice Coefficient
ft16.00Weir Length
(ft^0.5)/s3.00Weir Coefficient
1.00K Reverse
0.00Manning's n
0.00Kev, Charged Riser
FalseWeir Submergence
FalseOrifice H to crest
Structure ID: Media
Structure Type: User Defined Table
Flow
(ft³/s)
Elevation
(ft)
0.055620.00
0.073620.50
0.092621.00
0.110621.50
0.128622.00
0.146622.50
0.165623.00
0.183623.50
0.201624.00
Structure ID: TW
Structure Type: TW Setup, DS Channel
Free OutfallTailwater Type
Convergence Tolerances
30Maximum Iterations
ft0.01Tailwater Tolerance
(Minimum)
ft0.50Tailwater Tolerance
(Maximum)
ft0.01Headwater Tolerance
(Minimum)
ft0.50Headwater Tolerance
(Maximum)
ft³/s0.001Flow Tolerance (Minimum)
ft³/s10.000Flow Tolerance (Maximum)
7/17/2019COU15000.ppc
J. Mattingly, EIBelshire Subdivision
Storm Event: WQVLabel: SCM B
Return Event: 0 yearsSubsection: Composite Rating Curve
Composite Outflow Summary
Contributing StructuresConvergence Error
(ft)
Tailwater Elevation
(ft)
Flow
(ft³/s)
Water Surface
Elevation
(ft)
Media,Culvert (no Q:
Riser)
0.00(N/A)0.055620.00
Media,Culvert (no Q:
Riser)
0.00(N/A)0.058620.10
Media,Culvert (no Q:
Riser)
0.00(N/A)0.062620.20
Media,Culvert (no Q:
Riser)
0.00(N/A)0.065620.30
Media,Culvert (no Q:
Riser)
0.00(N/A)0.069620.40
Media,Culvert (no Q:
Riser)
0.00(N/A)0.073620.50
Media,Culvert (no Q:
Riser)
0.00(N/A)0.077620.60
Media,Culvert (no Q:
Riser)
0.00(N/A)0.081620.70
Media,Culvert (no Q:
Riser)
0.00(N/A)0.084620.80
Media,Culvert (no Q:
Riser)
0.00(N/A)0.089620.90
Media,Culvert (no Q:
Riser)
0.00(N/A)0.092621.00
Media,Culvert (no Q:
Riser)
0.00(N/A)0.096621.10
Media,Culvert (no Q:
Riser)
0.00(N/A)0.099621.20
Media,Culvert (no Q:
Riser)
0.00(N/A)0.103621.30
Media,Culvert (no Q:
Riser)
0.00(N/A)0.107621.40
Media,Culvert (no Q:
Riser)
0.00(N/A)0.111621.50
Media,Culvert (no Q:
Riser)
0.00(N/A)0.114621.60
Media,Culvert (no Q:
Riser)
0.00(N/A)0.116621.70
Media,Culvert (no Q:
Riser)
0.00(N/A)0.121621.80
Media,Culvert (no Q:
Riser)
0.00(N/A)0.123621.90
Media,Culvert (no Q:
Riser)
0.00(N/A)0.128622.00
Media,Culvert (no Q:
Riser)
0.00(N/A)0.132622.10
Media,Culvert (no Q:
Riser)
0.00(N/A)0.134622.20
Media,Culvert (no Q:
Riser)
0.00(N/A)0.138622.30
Media,Culvert (no Q:
Riser)
0.00(N/A)0.143622.40
Media,Culvert (no Q:
Riser)
0.00(N/A)0.146622.50
Media,Culvert (no Q:
Riser)
0.00(N/A)0.149622.60
7/17/2019COU15000.ppc
J. Mattingly, EIBelshire Subdivision
Storm Event: WQVLabel: SCM B
Return Event: 0 yearsSubsection: Composite Rating Curve
Composite Outflow Summary
Contributing StructuresConvergence Error
(ft)
Tailwater Elevation
(ft)
Flow
(ft³/s)
Water Surface
Elevation
(ft)
Media,Culvert (no Q:
Riser)
0.00(N/A)0.153622.70
Media,Culvert (no Q:
Riser)
0.00(N/A)0.157622.80
Media,Culvert (no Q:
Riser)
0.00(N/A)0.161622.90
Media,Culvert (no Q:
Riser)
0.00(N/A)0.165623.00
Riser,Media,Culvert0.00(N/A)1.686623.10
Riser,Media,Culvert0.00(N/A)4.465623.20
Riser,Media,Culvert0.00(N/A)8.063623.30
Riser,Media,Culvert0.00(N/A)12.315623.40
Riser,Media,Culvert0.00(N/A)17.156623.50
Riser,Media,Culvert0.00(N/A)22.495623.60
Riser,Media,Culvert0.00(N/A)28.300623.70
Riser,Media,Culvert0.00(N/A)34.541623.80
Riser,Media,Culvert0.00(N/A)41.181623.90
Riser,Media,Culvert0.00(N/A)43.792624.00
7/17/2019COU15000.ppc
J. Mattingly, EIBelshire Subdivision
Storm Event: WQVLabel: SB B
Return Event: 0 yearsSubsection: Interconnected Pond Routing Summary
Infiltration
No InfiltrationInfiltration Method
(Computed)
Initial Conditions Calculation Tolerances
ft623.75Elevation (Starting Water
Surface Computed)
ft³/s0.000Flow Tolerance (Minimum)
ft³0.000Volume (Starting) 35Maximum Iterations
ft³/s0.000Outflow (Starting) min3.00ICPM Time Step
21.000625.55716.50
Volume
(ft³)
Elevation
(ft)
Time to
Peak
(min)
Maximum Storage
0.0000.00
0.0000.00
Flow (Peak)
(ft³/s)
Time to Peak
(min)
Reverse Flow Peaks
6.049716.50Pond Outflow...
6.074716.00Pond Inflow....
Flow (Peak)
(ft³/s)
Time to Peak
(min)
Forward Flow Peaks
Forward14,659.000
Reverse0.000
DirectionVolume
(ft³)
Total Volume Out
Reverse0.000Pond Outflow...
Forward14,662.000Pond Inflow....
DirectionVolume
(ft³)
Total Volume In
Mass Balance (ft³)
ft³0.000Volume (Initial ICPM)
ft³14,662.000Volume (Total In ICPM)
ft³14,659.000Volume (Total Out ICPM)
ft³2.000Volume (Ending)
ft623.93Elevation (Ending)
ft³1.000Difference
%0.0
Percent of Inflow Volume
(Interconnected Pond Mass
Balance)
7/17/2019COU15000.ppc
J. Mattingly, EIBelshire Subdivision
Storm Event: WQVLabel: SCM B
Return Event: 0 yearsSubsection: Interconnected Pond Routing Summary
Infiltration
No InfiltrationInfiltration Method
(Computed)
Initial Conditions Calculation Tolerances
ft620.00Elevation (Starting Water
Surface Computed)
ft³/s0.000Flow Tolerance (Minimum)
ft³0.000Volume (Starting) 35Maximum Iterations
ft³/s0.055Outflow (Starting) min3.00ICPM Time Step
9,451.000622.751,079.50
Volume
(ft³)
Elevation
(ft)
Time to
Peak
(min)
Maximum Storage
0.0000.00
0.0000.00
Flow (Peak)
(ft³/s)
Time to Peak
(min)
Reverse Flow Peaks
0.1551,083.00Pond Outflow...
6.304716.50Pond Inflow....
Flow (Peak)
(ft³/s)
Time to Peak
(min)
Forward Flow Peaks
Forward6,750.000
Reverse0.000
DirectionVolume
(ft³)
Total Volume Out
Reverse0.000Pond Outflow...
Forward15,380.000Pond Inflow....
DirectionVolume
(ft³)
Total Volume In
Mass Balance (ft³)
ft³0.000Volume (Initial ICPM)
ft³15,380.000Volume (Total In ICPM)
ft³6,750.000Volume (Total Out ICPM)
ft³8,677.000Volume (Ending)
ft622.60Elevation (Ending)
ft³-47.000Difference
%0.3
Percent of Inflow Volume
(Interconnected Pond Mass
Balance)
7/17/2019COU15000.ppc
J. Mattingly, EIBelshire Subdivision
Storm Event: 2 yearLabel: SCM B
Return Event: 2 yearsSubsection: Interconnected Pond Routing Summary
Infiltration
No InfiltrationInfiltration Method
(Computed)
Initial Conditions Calculation Tolerances
ft620.00Elevation (Starting Water
Surface Computed)
ft³/s0.000Flow Tolerance (Minimum)
ft³0.000Volume (Starting) 35Maximum Iterations
ft³/s0.055Outflow (Starting) min3.00ICPM Time Step
12,263.000623.26730.00
Volume
(ft³)
Elevation
(ft)
Time to
Peak
(min)
Maximum Storage
0.0000.00
0.0000.00
Flow (Peak)
(ft³/s)
Time to Peak
(min)
Reverse Flow Peaks
6.761730.00Pond Outflow...
9.357721.00Pond Inflow....
Flow (Peak)
(ft³/s)
Time to Peak
(min)
Forward Flow Peaks
Forward36,227.000
Reverse0.000
DirectionVolume
(ft³)
Total Volume Out
Reverse0.000Pond Outflow...
Forward46,874.000Pond Inflow....
DirectionVolume
(ft³)
Total Volume In
Mass Balance (ft³)
ft³0.000Volume (Initial ICPM)
ft³46,874.000Volume (Total In ICPM)
ft³36,227.000Volume (Total Out ICPM)
ft³10,774.000Volume (Ending)
ft623.01Elevation (Ending)
ft³-127.000Difference
%0.3
Percent of Inflow Volume
(Interconnected Pond Mass
Balance)
7/17/2019COU15000.ppc
J. Mattingly, EIBelshire Subdivision
Storm Event: 10 yearLabel: SCM B
Return Event: 10 yearsSubsection: Interconnected Pond Routing Summary
Infiltration
No InfiltrationInfiltration Method
(Computed)
Initial Conditions Calculation Tolerances
ft620.00Elevation (Starting Water
Surface Computed)
ft³/s0.000Flow Tolerance (Minimum)
ft³0.000Volume (Starting) 35Maximum Iterations
ft³/s0.055Outflow (Starting) min3.00ICPM Time Step
12,772.000623.35723.50
Volume
(ft³)
Elevation
(ft)
Time to
Peak
(min)
Maximum Storage
0.0000.00
0.0000.00
Flow (Peak)
(ft³/s)
Time to Peak
(min)
Reverse Flow Peaks
10.190723.50Pond Outflow...
10.796721.50Pond Inflow....
Flow (Peak)
(ft³/s)
Time to Peak
(min)
Forward Flow Peaks
Forward64,152.000
Reverse0.000
DirectionVolume
(ft³)
Total Volume Out
Reverse0.000Pond Outflow...
Forward74,929.000Pond Inflow....
DirectionVolume
(ft³)
Total Volume In
Mass Balance (ft³)
ft³0.000Volume (Initial ICPM)
ft³74,929.000Volume (Total In ICPM)
ft³64,152.000Volume (Total Out ICPM)
ft³10,854.000Volume (Ending)
ft623.02Elevation (Ending)
ft³-77.000Difference
%0.1
Percent of Inflow Volume
(Interconnected Pond Mass
Balance)
7/17/2019COU15000.ppc
J. Mattingly, EIBelshire Subdivision
Storm Event: 25 yearLabel: SCM B
Return Event: 25 yearsSubsection: Interconnected Pond Routing Summary
Infiltration
No InfiltrationInfiltration Method
(Computed)
Initial Conditions Calculation Tolerances
ft620.00Elevation (Starting Water
Surface Computed)
ft³/s0.000Flow Tolerance (Minimum)
ft³0.000Volume (Starting) 35Maximum Iterations
ft³/s0.055Outflow (Starting) min3.00ICPM Time Step
12,879.000623.37723.50
Volume
(ft³)
Elevation
(ft)
Time to
Peak
(min)
Maximum Storage
0.0000.00
0.0000.00
Flow (Peak)
(ft³/s)
Time to Peak
(min)
Reverse Flow Peaks
10.963723.50Pond Outflow...
11.620721.50Pond Inflow....
Flow (Peak)
(ft³/s)
Time to Peak
(min)
Forward Flow Peaks
Forward81,689.000
Reverse0.000
DirectionVolume
(ft³)
Total Volume Out
Reverse0.000Pond Outflow...
Forward92,482.000Pond Inflow....
DirectionVolume
(ft³)
Total Volume In
Mass Balance (ft³)
ft³0.000Volume (Initial ICPM)
ft³92,482.000Volume (Total In ICPM)
ft³81,689.000Volume (Total Out ICPM)
ft³10,900.000Volume (Ending)
ft623.03Elevation (Ending)
ft³-107.000Difference
%0.1
Percent of Inflow Volume
(Interconnected Pond Mass
Balance)
7/17/2019COU15000.ppc
J. Mattingly, EIBelshire Subdivision
Storm Event: 50 yearLabel: SCM B
Return Event: 50 yearsSubsection: Interconnected Pond Routing Summary
Infiltration
No InfiltrationInfiltration Method
(Computed)
Initial Conditions Calculation Tolerances
ft620.00Elevation (Starting Water
Surface Computed)
ft³/s0.000Flow Tolerance (Minimum)
ft³0.000Volume (Starting) 35Maximum Iterations
ft³/s0.055Outflow (Starting) min3.00ICPM Time Step
12,957.000623.38723.00
Volume
(ft³)
Elevation
(ft)
Time to
Peak
(min)
Maximum Storage
0.0000.00
0.0000.00
Flow (Peak)
(ft³/s)
Time to Peak
(min)
Reverse Flow Peaks
11.528723.00Pond Outflow...
12.243721.50Pond Inflow....
Flow (Peak)
(ft³/s)
Time to Peak
(min)
Forward Flow Peaks
Forward88,240.000
Reverse0.000
DirectionVolume
(ft³)
Total Volume Out
Reverse0.000Pond Outflow...
Forward96,740.000Pond Inflow....
DirectionVolume
(ft³)
Total Volume In
Mass Balance (ft³)
ft³0.000Volume (Initial ICPM)
ft³96,740.000Volume (Total In ICPM)
ft³88,240.000Volume (Total Out ICPM)
ft³8,592.000Volume (Ending)
ft622.58Elevation (Ending)
ft³-92.000Difference
%0.1
Percent of Inflow Volume
(Interconnected Pond Mass
Balance)
7/17/2019COU15000.ppc
J. Mattingly, EIBelshire Subdivision
Storm Event: 100 yearLabel: SCM B
Return Event: 100 yearsSubsection: Interconnected Pond Routing Summary
Infiltration
No InfiltrationInfiltration Method
(Computed)
Initial Conditions Calculation Tolerances
ft620.00Elevation (Starting Water
Surface Computed)
ft³/s0.000Flow Tolerance (Minimum)
ft³0.000Volume (Starting) 35Maximum Iterations
ft³/s0.055Outflow (Starting) min3.00ICPM Time Step
13,026.000623.39723.00
Volume
(ft³)
Elevation
(ft)
Time to
Peak
(min)
Maximum Storage
0.0000.00
0.0000.00
Flow (Peak)
(ft³/s)
Time to Peak
(min)
Reverse Flow Peaks
12.027723.00Pond Outflow...
12.786721.50Pond Inflow....
Flow (Peak)
(ft³/s)
Time to Peak
(min)
Forward Flow Peaks
Forward113,367.000
Reverse0.000
DirectionVolume
(ft³)
Total Volume Out
Reverse0.000Pond Outflow...
Forward124,284.000Pond Inflow....
DirectionVolume
(ft³)
Total Volume In
Mass Balance (ft³)
ft³0.000Volume (Initial ICPM)
ft³124,284.000Volume (Total In ICPM)
ft³113,367.000Volume (Total Out ICPM)
ft³10,979.000Volume (Ending)
ft623.05Elevation (Ending)
ft³-62.000Difference
%0.1
Percent of Inflow Volume
(Interconnected Pond Mass
Balance)
7/17/2019COU15000.ppc
J. Mattingly, EIBelshire Subdivision
Project Name:Belshire Date:7/16/2019
Project Number:COU-15000 Calculated By:J. Mattingly
Facility ID:SCM B
INPUT DATA
Inside Length =4.00 ft
Inside Width =4.00 ft
Wall Thickness =6.00 in
Standard Base Length =5.00 ft
Standard Base Width =5.00 ft
Standard Base Thickness =6.00 in
Inside Height of Riser =8.00 ft
Concrete Unit Weight =142.00 pcf Unit weight of manhole concrete is 142 pcf per NC Products
Outside Diameter of Barrel =30.00 in
Drain Pipe (if present) =6.00 in
TRASH RACK DISPLACEMENT
Bottom Length / Width =8.40 ft Calculation for truncated square pyramid
Top Length / Width =2.10 ft
Height =2.00 ft
Trash Rack Displacement =61.740 cf
CONCRETE PRESENT IN RISER STRUCTURE
Riser Walls =72.000 cf
Standard Base of Riser =12.500 cf
Less Opening for Barrel =2.454 cf
Less Opening for Drain Pipe =0.098 cf
Less Opening for Orifice =4.500 cf
Total Concrete Less Openings =77.447 cf
Weight of Concrete =10,998 lbs
AMOUNT OF WATER DISPLACED BY RISER STRUCTURE
Displacement by Concrete =77.447 cf
Displacement by Open Air =128.000 cf
Displacement by Trash Rack =61.740 cf
Total Water Displaced =267.187 cf
Weight of Water Displaced =16,672 lbs
RISER ANTI-FLOTATION CALCULATION
AMOUNT OF CONCRETE TO ADD TO RISER STRUCTURE
Safety Factor =1.15 Recommend 1.15 or higher
Add'l Weight for Bouyancy =8,176 lbs
Bouyant Weight of Concrete =79.60 pcf
Bouyant Weight w/ SF =69.22 pcf
Add'l Concrete to Add =118.118 cf
Less Standard Base =12.500 cf
New Base Design Required =130.618 cf
ANTI FLOTATION BLOCK DESIGN CALCULATIONS
AF Block Length =8.00 ft
AF Block Width =8.00 ft
AF Block Thickness =30.00 in
AF Block Provided =160.000 cf
Total Concrete Present =229.447 cf
Total Concrete Present =32,582 lbs
Project Name: Belshire of Waxhaw Date: 7/17/2019
Project Number: COU-15000 Calculated By:Jessica Mattingly, EI
Facility ID: SCM B
DESIGN OF RIPRAP OUTLET PROTECTION
Calculations based on NY DOT method - Pages 8.06.05 through 8.06.06 in NC Erosion Control Manual.
Flow, Q10-yr =10.19 cfs
Slope =5.56 %
Pipe Diameter, Do =24 in
=2.00 feet
Number of pipes =1
Pipe separation =0.00 feet
Manning's n =0.013
Zone from graph above =3
Outlet pipe diameter =24 in Length =16.00 ft
Outlet flowrate =10.19 cfs Width =6.00 ft
Outlet velocity =13.11 ft/sec Stone diameter =13.00 in
Material =Class I Thickness =22.00 in
Zone Material Diameter Thickness Length Width
1 Class A 3 9 4 x Do 3 x Do
2 Class B 6 22 6 x Do 3 x Do
3 Class I 13 22 8 x Do 3 x Do
4 Class I 13 22 8 x Do 3 x Do
5 Class II 23 27 10 x Do 3 x Do
6 Class II 23 27 10 x Do 3 x Do
7 Study Required
RIPRAP OUTLET PROTECTION
13.11 ft/sec
0
5
10
15
20
25
0 1 2 3 4 5 6 7 8 9 10Velocity (ft/sec)Pipe diameter (ft)
Figure 8.06.b.1
Zone 1
Zone 2
Zone 3
Zone 4
Zone 5
Zone 6 Zone 7
BELSHIRE OF WAXHAW
COU-15000
DESIGN OF POND RETROFIT
Project Name:Belshire Date:7/15/2019
Project Number:COU-15000 Calculated By:J. Mattingly
Facility ID:DESIGN
ABOVE NORMAL POOL
Average Incremental Accumulated Calculated
Contour Stage Contour Area Contour Area Contour Vol Contour Vol Stage
[ft][ft][sf][sf][cf][cf][ft]
616.50 0.00 62,920
617.00 0.50 68,816 65,868 32,934 32,934 0.50
618.00 1.50 77,964 73,390 73,390 106,324 1.47
619.00 2.50 86,129 82,047 82,047 188,371 2.49
620.00 3.50 93,457 89,793 89,793 278,164 3.55
b =1.0932
Ks =69597
STAGE-STORAGE FUNCTION - ABOVE NORMAL POOL
y = 69597x1.0932
R² = 0.9997
0
50,000
100,000
150,000
200,000
250,000
300,000
0.00 0.50 1.00 1.50 2.00 2.50 3.00 3.50 4.00Storage (CF)Stage (feet)
Storage vs. Stage
Storm Event: WQVLabel: POND
Return Event: 0 yearsSubsection: Elevation-Area Volume Curve
Volume (Total)
(ft³)
Volume
(ft³)
A1+A2+sqr
(A1*A2)
(ft²)
Area
(ft²)
Planimeter
(ft²)
Elevation
(ft)
0.0000.0000.0062,920.000.000616.50
32,923.00032,923.000197,538.0068,816.000.000617.00
106,265.00073,342.000220,027.3377,964.000.000618.00
188,278.00082,013.000246,037.8786,129.000.000619.00
278,046.00089,768.000269,304.2193,457.000.000620.00
7/15/2019COU15000.ppc
J. Mattingly, EIBelshire Subdivision
Storm Event: WQVLabel: POND
Return Event: 0 yearsSubsection: Outlet Input Data
Requested Pond Water Surface Elevations
ft616.50Minimum (Headwater)
ft0.50Increment (Headwater)
ft620.00Maximum (Headwater)
Outlet Connectivity
E2
(ft)
E1
(ft)
OutfallDirectionOutlet IDStructure Type
620.00618.00CulvertForwardRiserInlet Box
620.00616.50CulvertForwardOrificeOrifice-Circular
620.00611.00TWForwardCulvertCulvert-Circular
(N/A)(N/A)TailwaterTailwater Settings
7/18/2019COU15000.ppc
J. Mattingly, EIBelshire Subdivision
Storm Event: WQVLabel: POND
Return Event: 0 yearsSubsection: Outlet Input Data
Structure ID: Orifice
Structure Type: Orifice-Circular
1Number of Openings
ft616.50Elevation
in1.5Orifice Diameter
0.60Orifice Coefficient
7/18/2019COU15000.ppc
J. Mattingly, EIBelshire Subdivision
Storm Event: WQVLabel: POND
Return Event: 0 yearsSubsection: Outlet Input Data
Structure ID: Culvert
Structure Type: Culvert-Circular
1Number of Barrels
in48.0Diameter
ft35.00Length
ft35.01Length (Computed Barrel)
ft/ft0.029Slope (Computed)
Outlet Control Data
0.013Manning's n
0.50Ke
0.00Kb
0.00Kr
ft0.00Convergence Tolerance
Inlet Control Data
Form 1Equation Form
0.0098K
2.0000M
0.0398C
0.6700Y
0.00T1 ratio (HW/D)
1.29T2 ratio (HW/D)
-0.50Slope Correction Factor
Use unsubmerged inlet control 0 equation below T1 elevation.
Use submerged inlet control 0 equation above T2 elevation
In transition zone between unsubmerged and submerged inlet
control,
interpolate between flows at T1 & T2...
ft611.00T1 Elevation ft³/s87.965T1 Flow
ft616.17T2 Elevation ft³/s100.531T2 Flow
7/18/2019COU15000.ppc
J. Mattingly, EIBelshire Subdivision
Storm Event: WQVLabel: POND
Return Event: 0 yearsSubsection: Outlet Input Data
Structure ID: Riser
Structure Type: Inlet Box
1Number of Openings
ft618.00Elevation
ft²36.000Orifice Area
0.60Orifice Coefficient
ft24.00Weir Length
(ft^0.5)/s3.00Weir Coefficient
1.00K Reverse
0.00Manning's n
0.00Kev, Charged Riser
FalseWeir Submergence
FalseOrifice H to crest
Structure ID: TW
Structure Type: TW Setup, DS Channel
Free OutfallTailwater Type
Convergence Tolerances
30Maximum Iterations
ft0.01Tailwater Tolerance
(Minimum)
ft0.50Tailwater Tolerance
(Maximum)
ft0.01Headwater Tolerance
(Minimum)
ft0.50Headwater Tolerance
(Maximum)
ft³/s0.001Flow Tolerance (Minimum)
ft³/s10.000Flow Tolerance (Maximum)
7/18/2019COU15000.ppc
J. Mattingly, EIBelshire Subdivision
Storm Event: WQVLabel: POND
Return Event: 0 yearsSubsection: Composite Rating Curve
Composite Outflow Summary
Contributing StructuresConvergence Error
(ft)
Tailwater Elevation
(ft)
Flow
(ft³/s)
Water Surface
Elevation
(ft)
(no Q:
Riser,Orifice,Culvert)
0.00(N/A)0.000616.50
Orifice,Culvert (no Q:
Riser)
0.00(N/A)0.039617.00
Orifice,Culvert (no Q:
Riser)
0.00(N/A)0.058617.50
Orifice,Culvert (no Q:
Riser)
0.00(N/A)0.071618.00
Riser,Orifice,Culvert0.00(N/A)25.535618.50
Riser,Orifice,Culvert0.00(N/A)72.062619.00
Riser,Orifice,Culvert0.00(N/A)132.344619.50
Riser,Culvert (no Q:
Orifice)
0.00(N/A)159.073620.00
7/18/2019COU15000.ppc
J. Mattingly, EIBelshire Subdivision
Storm Event: WQVLabel: POND
Return Event: 0 yearsSubsection: Interconnected Pond Routing Summary
Infiltration
No InfiltrationInfiltration Method
(Computed)
Initial Conditions Calculation Tolerances
ft616.50Elevation (Starting Water
Surface Computed)
ft³/s0.000Flow Tolerance (Minimum)
ft³0.000Volume (Starting) 35Maximum Iterations
ft³/s0.000Outflow (Starting) min3.00ICPM Time Step
4,440.000616.571,439.50
Volume
(ft³)
Elevation
(ft)
Time to
Peak
(min)
Maximum Storage
0.0000.00
0.0000.00
Flow (Peak)
(ft³/s)
Time to Peak
(min)
Reverse Flow Peaks
0.0051,440.00Pond Outflow...
1.324721.00Pond Inflow....
Flow (Peak)
(ft³/s)
Time to Peak
(min)
Forward Flow Peaks
Forward159.000
Reverse0.000
DirectionVolume
(ft³)
Total Volume Out
Reverse0.000Pond Outflow...
Forward4,601.000Pond Inflow....
DirectionVolume
(ft³)
Total Volume In
Mass Balance (ft³)
ft³0.000Volume (Initial ICPM)
ft³4,601.000Volume (Total In ICPM)
ft³159.000Volume (Total Out ICPM)
ft³4,441.000Volume (Ending)
ft616.57Elevation (Ending)
ft³0.000Difference
%0.0
Percent of Inflow Volume
(Interconnected Pond Mass
Balance)
7/18/2019COU15000.ppc
J. Mattingly, EIBelshire Subdivision
Storm Event: 2 yearLabel: POND
Return Event: 2 yearsSubsection: Interconnected Pond Routing Summary
Infiltration
No InfiltrationInfiltration Method
(Computed)
Initial Conditions Calculation Tolerances
ft616.50Elevation (Starting Water
Surface Computed)
ft³/s0.000Flow Tolerance (Minimum)
ft³0.000Volume (Starting) 35Maximum Iterations
ft³/s0.000Outflow (Starting) min3.00ICPM Time Step
57,568.000617.341,440.00
Volume
(ft³)
Elevation
(ft)
Time to
Peak
(min)
Maximum Storage
0.0000.00
0.0000.00
Flow (Peak)
(ft³/s)
Time to Peak
(min)
Reverse Flow Peaks
0.0521,440.00Pond Outflow...
48.333722.00Pond Inflow....
Flow (Peak)
(ft³/s)
Time to Peak
(min)
Forward Flow Peaks
Forward2,065.000
Reverse0.000
DirectionVolume
(ft³)
Total Volume Out
Reverse0.000Pond Outflow...
Forward59,633.000Pond Inflow....
DirectionVolume
(ft³)
Total Volume In
Mass Balance (ft³)
ft³0.000Volume (Initial ICPM)
ft³59,633.000Volume (Total In ICPM)
ft³2,065.000Volume (Total Out ICPM)
ft³57,568.000Volume (Ending)
ft617.34Elevation (Ending)
ft³1.000Difference
%0.0
Percent of Inflow Volume
(Interconnected Pond Mass
Balance)
7/18/2019COU15000.ppc
J. Mattingly, EIBelshire Subdivision
Storm Event: 10 yearLabel: POND
Return Event: 10 yearsSubsection: Interconnected Pond Routing Summary
Infiltration
No InfiltrationInfiltration Method
(Computed)
Initial Conditions Calculation Tolerances
ft616.50Elevation (Starting Water
Surface Computed)
ft³/s0.000Flow Tolerance (Minimum)
ft³0.000Volume (Starting) 35Maximum Iterations
ft³/s0.000Outflow (Starting) min3.00ICPM Time Step
108,681.00
0618.03900.50
Volume
(ft³)
Elevation
(ft)
Time to
Peak
(min)
Maximum Storage
0.0000.00
0.0000.00
Flow (Peak)
(ft³/s)
Time to Peak
(min)
Reverse Flow Peaks
1.572901.50Pond Outflow...
91.809721.50Pond Inflow....
Flow (Peak)
(ft³/s)
Time to Peak
(min)
Forward Flow Peaks
Forward33,248.000
Reverse0.000
DirectionVolume
(ft³)
Total Volume Out
Reverse0.000Pond Outflow...
Forward140,398.000Pond Inflow....
DirectionVolume
(ft³)
Total Volume In
Mass Balance (ft³)
ft³0.000Volume (Initial ICPM)
ft³140,398.000Volume (Total In ICPM)
ft³33,248.000Volume (Total Out ICPM)
ft³107,141.000Volume (Ending)
ft618.01Elevation (Ending)
ft³9.000Difference
%0.0
Percent of Inflow Volume
(Interconnected Pond Mass
Balance)
7/18/2019COU15000.ppc
J. Mattingly, EIBelshire Subdivision
Storm Event: 25 yearLabel: POND
Return Event: 25 yearsSubsection: Interconnected Pond Routing Summary
Infiltration
No InfiltrationInfiltration Method
(Computed)
Initial Conditions Calculation Tolerances
ft616.50Elevation (Starting Water
Surface Computed)
ft³/s0.000Flow Tolerance (Minimum)
ft³0.000Volume (Starting) 35Maximum Iterations
ft³/s0.000Outflow (Starting) min3.00ICPM Time Step
128,037.00
0618.27754.50
Volume
(ft³)
Elevation
(ft)
Time to
Peak
(min)
Maximum Storage
0.0000.00
0.0000.00
Flow (Peak)
(ft³/s)
Time to Peak
(min)
Reverse Flow Peaks
13.591754.50Pond Outflow...
113.596721.50Pond Inflow....
Flow (Peak)
(ft³/s)
Time to Peak
(min)
Forward Flow Peaks
Forward88,878.000
Reverse0.000
DirectionVolume
(ft³)
Total Volume Out
Reverse0.000Pond Outflow...
Forward196,326.000Pond Inflow....
DirectionVolume
(ft³)
Total Volume In
Mass Balance (ft³)
ft³0.000Volume (Initial ICPM)
ft³196,326.000Volume (Total In ICPM)
ft³88,878.000Volume (Total Out ICPM)
ft³107,436.000Volume (Ending)
ft618.01Elevation (Ending)
ft³12.000Difference
%0.0
Percent of Inflow Volume
(Interconnected Pond Mass
Balance)
7/18/2019COU15000.ppc
J. Mattingly, EIBelshire Subdivision
Storm Event: 50 yearLabel: POND
Return Event: 50 yearsSubsection: Interconnected Pond Routing Summary
Infiltration
No InfiltrationInfiltration Method
(Computed)
Initial Conditions Calculation Tolerances
ft616.50Elevation (Starting Water
Surface Computed)
ft³/s0.000Flow Tolerance (Minimum)
ft³0.000Volume (Starting) 35Maximum Iterations
ft³/s0.000Outflow (Starting) min3.00ICPM Time Step
144,235.00
0618.46753.50
Volume
(ft³)
Elevation
(ft)
Time to
Peak
(min)
Maximum Storage
0.0000.00
0.0000.00
Flow (Peak)
(ft³/s)
Time to Peak
(min)
Reverse Flow Peaks
23.649753.50Pond Outflow...
130.286721.50Pond Inflow....
Flow (Peak)
(ft³/s)
Time to Peak
(min)
Forward Flow Peaks
Forward123,869.000
Reverse0.000
DirectionVolume
(ft³)
Total Volume Out
Reverse0.000Pond Outflow...
Forward229,498.000Pond Inflow....
DirectionVolume
(ft³)
Total Volume In
Mass Balance (ft³)
ft³0.000Volume (Initial ICPM)
ft³229,498.000Volume (Total In ICPM)
ft³123,869.000Volume (Total Out ICPM)
ft³105,628.000Volume (Ending)
ft617.99Elevation (Ending)
ft³1.000Difference
%0.0
Percent of Inflow Volume
(Interconnected Pond Mass
Balance)
7/18/2019COU15000.ppc
J. Mattingly, EIBelshire Subdivision
Storm Event: 100 yearLabel: POND
Return Event: 100 yearsSubsection: Interconnected Pond Routing Summary
Infiltration
No InfiltrationInfiltration Method
(Computed)
Initial Conditions Calculation Tolerances
ft616.50Elevation (Starting Water
Surface Computed)
ft³/s0.000Flow Tolerance (Minimum)
ft³0.000Volume (Starting) 35Maximum Iterations
ft³/s0.000Outflow (Starting) min3.00ICPM Time Step
157,123.00
0618.62752.50
Volume
(ft³)
Elevation
(ft)
Time to
Peak
(min)
Maximum Storage
0.0000.00
0.0000.00
Flow (Peak)
(ft³/s)
Time to Peak
(min)
Reverse Flow Peaks
36.712752.50Pond Outflow...
145.373721.50Pond Inflow....
Flow (Peak)
(ft³/s)
Time to Peak
(min)
Forward Flow Peaks
Forward184,244.000
Reverse0.000
DirectionVolume
(ft³)
Total Volume Out
Reverse0.000Pond Outflow...
Forward292,200.000Pond Inflow....
DirectionVolume
(ft³)
Total Volume In
Mass Balance (ft³)
ft³0.000Volume (Initial ICPM)
ft³292,200.000Volume (Total In ICPM)
ft³184,244.000Volume (Total Out ICPM)
ft³107,939.000Volume (Ending)
ft618.02Elevation (Ending)
ft³17.000Difference
%0.0
Percent of Inflow Volume
(Interconnected Pond Mass
Balance)
7/18/2019COU15000.ppc
J. Mattingly, EIBelshire Subdivision
Project Name:Belshire Date:7/18/2019
Project Number:COU-15000 Calculated By:J. Mattingly
Facility ID:Pond
INPUT DATA
Inside Length =6.00 ft
Inside Width =6.00 ft
Wall Thickness =6.00 in
Standard Base Length =7.00 ft
Standard Base Width =7.00 ft
Standard Base Thickness =6.00 in
Inside Height of Riser =7.00 ft
Concrete Unit Weight =142.00 pcf Unit weight of manhole concrete is 142 pcf per NC Products
Outside Diameter of Barrel =58.00 in
Drain Pipe (if present) =6.00 in
TRASH RACK DISPLACEMENT
Bottom Length / Width =8.40 ft Calculation for truncated square pyramid
Top Length / Width =2.10 ft
Height =2.00 ft
Trash Rack Displacement =61.740 cf
CONCRETE PRESENT IN RISER STRUCTURE
Riser Walls =91.000 cf
Standard Base of Riser =24.500 cf
Less Opening for Barrel =9.174 cf
Less Opening for Drain Pipe =0.098 cf
Less Opening for Orifice =4.500 cf
Total Concrete Less Openings =101.728 cf
Weight of Concrete =14,445 lbs
AMOUNT OF WATER DISPLACED BY RISER STRUCTURE
Displacement by Concrete =101.728 cf
Displacement by Open Air =252.000 cf
Displacement by Trash Rack =61.740 cf
Total Water Displaced =415.468 cf
Weight of Water Displaced =25,925 lbs
RISER ANTI-FLOTATION CALCULATION
AMOUNT OF CONCRETE TO ADD TO RISER STRUCTURE
Safety Factor =1.15 Recommend 1.15 or higher
Add'l Weight for Bouyancy =15,369 lbs
Bouyant Weight of Concrete =79.60 pcf
Bouyant Weight w/ SF =69.22 pcf
Add'l Concrete to Add =222.034 cf
Less Standard Base =24.500 cf
New Base Design Required =246.534 cf
ANTI FLOTATION BLOCK DESIGN CALCULATIONS
AF Block Length =8.00 ft
AF Block Width =8.00 ft
AF Block Thickness =47.00 in
AF Block Provided =250.667 cf
Total Concrete Present =332.395 cf
Total Concrete Present =47,200 lbs
Project Name: Belshire of Waxhaw Date: 7/18/2019
Project Number: COU-15000 Calculated By:Jessica Mattingly, EI
Facility ID: POND
DESIGN OF RIPRAP OUTLET PROTECTION
Calculations based on NY DOT method - Pages 8.06.05 through 8.06.06 in NC Erosion Control Manual.
Flow, Q10-yr =1.57 cfs
Slope =2.86 %
Pipe Diameter, Do =48 in
=4.00 feet
Number of pipes =1
Pipe separation =0.00 feet
Manning's n =0.013
Zone from graph above =2
Outlet pipe diameter =48 in Length =24.00 ft
Outlet flowrate =1.57 cfs Width =12.00 ft
Outlet velocity =5.44 ft/sec Stone diameter =6.00 in
Material =Class B Thickness =22.00 in
Zone Material Diameter Thickness Length Width
1 Class A 3 9 4 x Do 3 x Do
2 Class B 6 22 6 x Do 3 x Do
3 Class I 13 22 8 x Do 3 x Do
4 Class I 13 22 8 x Do 3 x Do
5 Class II 23 27 10 x Do 3 x Do
6 Class II 23 27 10 x Do 3 x Do
7 Study Required
RIPRAP OUTLET PROTECTION
5.44 ft/sec
0
5
10
15
20
25
0 1 2 3 4 5 6 7 8 9 10Velocity (ft/sec)Pipe diameter (ft)
Figure 8.06.b.1
Zone 1
Zone 2
Zone 3
Zone 4
Zone 5
Zone 6 Zone 7
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