Franklin Medical Center - 2018-10-04_Stormwater Narrative

Stormwater Narrative

Franklin Medical Center – 20 Bed Addition
100 Hospital Drive
Louisburg, NC 27549

October 4, 2018

Table of Contents

Section

Narrative
Project Description
Site Description
Adjacent Property
Proposed Stormwater Design
Post Development Peak flows
Storm Sewer Analysis
Downstream Analysis

Supporting Calculations
Impervious Area Calculations
Hydrologic Soil Group - Site Map
USGS Map
Wet Pond Calculations
Existing Drainage Area Map
Proposed Drainage Area Map
Detention Calculations (Autodesk Hydraflow)
1-yr
2-yr
10-yr
25-yr
50-yr
100-yr
Storm Sewer Calculations (Autodesk Hydraflow)

Project Description
The proposed project is the construction of a new 20 Bed, 14,606 sq-ft building addition for Franklin
Medical Center on an 8.6 acre site. The site is located at 100 Hospital Drive, Louisburg, NC. A wet pond
is proposed to provide water quality and detention for the improved area of the site. The proposed wet
pond meets the requirements as indicated by the NCDEQ stormwater design manual. Runoff from the 2-
yr, 10-yr, 25-yr, 50-yr and 100-year storm are detained to release flows less than existing conditions.
The project is disturbing approximately 3.75 acres and will add 0.81 acres of new impervious area. An
active stormwater project number SW5120402 exists on-site for the previous building addition to the
hospital, but the proposed impervious area with that project was less than existing conditions, so no state
stormwater permitting was required. Since this stormwater project number did not fall under state
permitting requirements, the proposed project is being submitted as a new project.

Site Description
The total site is divided into two drainage areas. The proposed project is in drainage area 1 and is 5.09
acres and is made up of three sub-basins. Sub-basin 1 is made of 2.03 acres, which slopes approximately
5% to an existing detention pond to the west. Sub-basin 2 is made up of 2.28 acres, which slopes
approximately 6% to the southwest corner of the property. Sub-basin 3 is made up of 0.78 acres, which
slopes approximately 5% to the south property line. The second drainage area is the existing building
and the east side of the site, which is approximately 3.52 acres and no area is proposed to be disturbed
in this drainage area. The area within the property is made of impervious area or grass in fair condition.
Based on the NRCS Web Soil Survey, the site contains soils in the Hydrologic Group B. The existing area
to be disturbed is patient parking, an access drive, an open field, and a helipad serving the hospital. Sub-
basins 1 & 2 discharge to an existing 24” RCP pipe at the southwest corner of the property to an off-site
stormwater conveyance system. Sub-basin 3 eventually discharges to the same off-site stormwater
conveyance system. This stormwater conveyance system drains to Fox Creek, which drains to the Tar River.

Autodesk Hydraflow software was used to model the stormwater flows for the existing condition. The SCS
Method was used with a Curve Number (CN) of 69 for grass cover of soil type B. A CN of 98 was assigned
to impervious area. The weighted CN for the pre-development condition for the drainage area is 78. The
Time of Concentration for the existing Drainage Area was calculated to be less than 5 minutes, so 5 minutes
was assumed. The flow path for time of concentration can be found in the drainage area map attached.

The results for the peak outflows from the existing conditions are shown below:

Pre-development Peak Flows

1-yr 2-yr 10-yr 25-yr 50-yr 100-yr
Sub-basin cfs cfs cfs cfs cfs cfs
1 5.12 6.82 11.55 14.49 16.88 19.35
2 3.05 4.57 9.17 12.30 14.91 17.66
3 1.26 1.81 3.47 4.57 5.49 6.44

Adjacent Properties
The properties to the south of the proposed project are developed zone R-1 Single Family Residential.
The properties to the north are developed O& I Office and Institutional.

Proposed Stormwater Design
The post-development condition will as closely match that of the pre-development as possible. The
proposed project mostly affects sub-basin 2 and 3 of drainage area 1. Most of the existing sub-basin 3
has been routed to the wet pond because of the development taking place that requires treatment and
detention of the increased runoff. The proposed drainage area to the wet pond is 2.74 acres and
includes 1.53 acres of impervious area. The Simple Method for Runoff Volume was used to determine the
design volume for the wet pond, which is 5,497 cu-ft. The Hydraulic Retention Time Method was used to

determine the required permanent pool volume, which is 13,382 cu-ft. The permanent pool will have a
bottom surface area of 1,817 sq-ft at an invert elevation of 270.00’ and a ponding surface of 4,123 sq-
ft at an elevation of 274.75’. The total provided permanent pool volume is 13,858 cu-ft.

The bottom of the wet pond is 1,617 sq-ft at an invert elevation of 269.50’ to provide 6” of sediment
storage. A temporary pool is to start at the top of the permanent pool elevation and extend to an
elevation of 276.00’ with a ponding surface area of 8,134 sq-ft. This temporary pool will draw down
over 72 hours through a 0.60 inch orifice. The required temporary pooling volume is equal to the design
volume calculated, which is 5,497 cu-ft. The temporary pooling volume provided is approximately 8,319
cu-ft. A vegetated shelf is proposed in the temporary pooling volume. The vegetated shelf is proposed to
be 6-ft wide at a 6:1 H:V slope with a bottom elevation of 275.00’.

At an elevation of 276.00’, the temporary pooling volume has been met and a 2-ft wide weir in the outlet
structure controls the flow rate for larger storm events to be less than existing conditions to the same
southwest corner outlet point. The 100-yr storm elevation is 277.70’ and the top of the outlet structure and
the emergency spillway are at an elevation of 278.00’ to provide 1-ft of freeboard. Calculations for the
proposed wet pond can be found attached.

Post-Development Peak flows
Autodesk Storm & Sanitary Analysis software was used to model the post-development stormwater flows.
The SCS Method was used with a Curve Number (CN) of 98 for impervious area. A CN of 69 was assigned
to grass cover of soil type B. The Time of Concentration used for developed areas was calculated to be less
than 5 minutes, so 5 minutes was assumed.

The post-development peak outflows are provided below.

Post-development Peak Flows
1-yr 2-yr 10-yr 25-yr 50-yr 100-yr
Sub-basin cfs cfs cfs cfs cfs cfs
1 4.20 5.73 10.13 12.91 15.18 17.52
2 0.42 0.83 5.85 9.35 11.67 13.46
3 0.02 0.03 0.07 0.10 0.12 0.14

Comparing the peak flows of the existing conditions and post-development conditions show that for all storm
events, the post-developed site creates less flow than existing conditions for the 1-yr, 2-yr, 10-yr, 25-yr,
50-yr and 100-yr storm events.

Pre- vs. Post-development Peak Flows

Sub-basin 1
1-yr 2-yr 10-yr 25-yr 50-yr 100-yr
cfs cfs cfs cfs cfs cfs
Pre 5.12 6.82 11.55 14.49 16.88 19.35
Post 4.20 5.73 10.13 12.91 15.18 17.52

Sub-basin 2
1-yr 2-yr 10-yr 25-yr 50-yr 100-yr
cfs cfs cfs cfs cfs cfs
Pre 3.05 4.57 9.17 12.30 14.91 17.66
Post 0.42 0.83 5.85 9.35 11.67 13.46

Sub-basin 3
1-yr 2-yr 10-yr 25-yr 50-yr 100-yr
cfs cfs cfs cfs cfs cfs
Pre 1.26 1.81 3.47 4.57 5.49 6.44
Post 0.02 0.03 0.07 0.10 0.12 0.14

Storm Sewer Analysis
The proposed storm sewer pipes are designed for the 25-yr storm event using the rational method.
Stormwater is directed through storm pipes that discharge into the wet pond located to the southwest corner
of the property. Runoff will discharge from the site through an 18” HDPE pipe to an existing channel that
drains south along the west property line. This ditch drains to a 24” RCP pipe that discharges off-site to the
south.

Downstream Analysis
The post-development flows for the 1-yr through 100-yr storm are detained in the wet pond to discharge
less flow than existing conditions, so there is no adverse impact on erosion or capacity downstream.

Franklin Medical Center - Impervious Area Calculations
On-Site =374,616 sq-ft
=8.60 acres
Existing
West (Existing Pond) DA1-SB1 Southwest (DA1-SB2)
Area =88,253 sq-ft Area =99,442 sq-ft
=2.03 acres =2.28 acres
Building =- sq-ft Building =- sq-ft
Street =8,785 sq-ft Street =11,278 sq-ft
Parking =37,013 sq-ft Parking =- sq-ft
Sidewalk =1,454 sq-ft Sidewalk =1,925 sq-ft
Total =47,252 sq-ft Total =13,203 sq-ft
=1.08 acres =0.30 acres
Pervious Area (Soil B) =41,001 sq-ft Pervious Area (Soil B) =86,239 sq-ft
0.94 acres 1.98 acres
South (DA1-SB3)DA2 (Existing)
Area =33,776 sq-ft Area =153,145 sq-ft
=0.78 acres =3.52 acres
Building =- sq-ft Building =56,378 sq-ft
Street =8,091 sq-ft Street = 21,141 sq-ft
Parking =- sq-ft Parking =25,084 sq-ft
Sidewalk =681 sq-ft Sidewalk = 2,396 sq-ft
Total =8,091 sq-ft Total =104,999 sq-ft
=0.19 acres =2.41 acres
Pervious Area (Soil B) =25,685 sq-ft Pervious Area (Soil B) =48,146 sq-ft
0.59 acres 1.11 acres
Existing Imp. Area DA1 = 68,546 sq-ft Existing Imp. Area DA1 = 104,999 sq-ft
1.57 acres 2.41 acres
44.76%68.56%
Proposed
West (Existing Pond) DA1-SB1 South (DA1-SB3)
Area =83,200 sq-ft Area =702 sq-ft
=1.91 acres =0.02 acres
Building =- sq-ft Building =- sq-ft
Street =7,257 sq-ft Street =- sq-ft
Parking =sq-ft Parking =- sq-ft
Sidewalk =- sq-ft Sidewalk =- sq-ft
Existing Imp. To Remain = 29,847 sq-ft Existing Imp. To Remain = - sq-ft
Total =37,104 sq-ft Total =- sq-ft
=0.85 acres =- acres
Pervious Area (Soil B) =46,096 sq-ft Pervious Area (Soil B) =702 sq-ft
1.06 acres 0.02 acres
Southwest - Pond (DA1-SB2)Southwest - Bypass (DA1-SB2)
Area =119,331 sq-ft Area =18,304 sq-ft
=2.74 acres =0.42 acres
Building =14,605 sq-ft Building =- sq-ft
Street =27,282 sq-ft Street =- sq-ft
Parking =18,039 sq-ft Parking =- sq-ft
Sidewalk =3,941 sq-ft Sidewalk =- sq-ft
Existing Imp. To Remain = 2,802 sq-ft Existing Imp. To Remain = sq-ft
Total =66,669 sq-ft Total =- sq-ft
=1.53 acres =- acres
Pervious Area (Soil B) =52,662 sq-ft
1.21 acres
Proposed Imp. Area (DA1) = 103,773 sq-ft
2.38 acres
46.84%
DA2 (to remain the same)Total Site = 8.60 ac
Total Exi. Imp. To remain DA1 = 0.75 ac
Total Prop. Imp. DA1 = 1.63 ac
Total Exi. Imp. DA2 = 2.41 ac
Total Site Imp. = 55.73%
Hydrologic Soil Group—Franklin County, North Carolina
Natural Resources
Conservation Service
Web Soil Survey
National Cooperative Soil Survey
8/22/2018
Page 1 of 4399971039997403999770399980039998303999860399989039997103999740399977039998003999830399986039998903999920743340743370743400743430743460743490743520743550743580743610743640
743340 743370 743400 743430 743460 743490 743520 743550 743580 743610 743640 743670
36° 6' 48'' N 78° 17' 47'' W36° 6' 48'' N78° 17' 34'' W36° 6' 41'' N
78° 17' 47'' W36° 6' 41'' N
78° 17' 34'' WN
Map projection: Web Mercator Corner coordinates: WGS84 Edge tics: UTM Zone 17N WGS84
0 50 100 200 300
Feet
0 20 40 80 120
Meters
Map Scale: 1:1,550 if printed on A landscape (11" x 8.5") sheet.
Soil Map may not be valid at this scale.
MAP LEGEND MAP INFORMATION
Area of Interest (AOI)
Area of Interest (AOI)
Soils
Soil Rating Polygons
A
A/D
B
B/D
C
C/D
D
Not rated or not available
Soil Rating Lines
A
A/D
B
B/D
C
C/D
D
Not rated or not available
Soil Rating Points
A
A/D
B
B/D
C
C/D
D
Not rated or not available
Water Features
Streams and Canals
Transportation
Rails
Interstate Highways
US Routes
Major Roads
Local Roads
Background
Aerial Photography
The soil surveys that comprise your AOI were mapped at
1:24,000.
Warning: Soil Map may not be valid at this scale.
Enlargement of maps beyond the scale of mapping can cause
misunderstanding of the detail of mapping and accuracy of soil
line placement. The maps do not show the small areas of
contrasting soils that could have been shown at a more detailed
scale.
Please rely on the bar scale on each map sheet for map
measurements.
Source of Map: Natural Resources Conservation Service
Web Soil Survey URL:
Coordinate System: Web Mercator (EPSG:3857)
Maps from the Web Soil Survey are based on the Web Mercator
projection, which preserves direction and shape but distorts
distance and area. A projection that preserves area, such as the
Albers equal-area conic projection, should be used if more
accurate calculations of distance or area are required.
This product is generated from the USDA-NRCS certified data as
of the version date(s) listed below.
Soil Survey Area: Franklin County, North Carolina
Survey Area Data: Version 20, Oct 2, 2017
Soil map units are labeled (as space allows) for map scales
1:50,000 or larger.
Date(s) aerial images were photographed: May 25, 2016—Nov
17, 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—Franklin County, North Carolina
Natural Resources
Conservation Service
Web Soil Survey
National Cooperative Soil Survey
8/22/2018
Page 2 of 4
Hydrologic Soil Group
Map unit symbol Map unit name Rating Acres in AOI Percent of AOI
WuC Wedowee-Urban land-
Udorthents complex,
2 to 10 percent slopes
B 7.2 100.0%
Totals for Area of Interest 7.2 100.0%
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.
Rating Options
Aggregation Method: Dominant Condition
Hydrologic Soil Group—Franklin County, North Carolina
Natural Resources
Conservation Service
Web Soil Survey
National Cooperative Soil Survey
8/22/2018
Page 3 of 4
Component Percent Cutoff: None Specified
Tie-break Rule: Higher
Hydrologic Soil Group—Franklin County, North Carolina
Natural Resources
Conservation Service
Web Soil Survey
National Cooperative Soil Survey
8/22/2018
Page 4 of 4
Franklin Medical Center - Wet Pond CalculationsDrainage Area =119,331 sq-ft=2.74 acresImp. Area = 66,669 sq-ft=1.53 acres% Imp. Cover = 55.87%Simple Method for Runoff VolumeIA = 0.56Rv = 0.55RD = 1inchDV = 5,497 cu-ftHydraulic Retention Time MethodHRT = 14daysTs = 5daysVmp = 13,392 cu-ft=0.05+0.9∗DV=3630∗∗∗= 0.87 ∗∗
Wet Pond Volume ProvidedElevation (ft)Area (sf)Inc. Vol.Volume269.501617-859*6" sediment storage 270.00181700*Bottom elevation of wet pond storage271.00224820332033272.00270724784510273.00319729527462274.003716345710919274.754123294013858*Permanent Pool Elevation275.005978126315121*Vegetated Shelf276.008134705622177*Temporary Pool Elevation277.009297871630892278.0010517990740799279.00117931115551954Orifice SizingDesign Volume = 5,497 cu-ftDrawdown time = 72hoursQ =0.010604528cu-ft/sho = 1.25ftCD = 0.60g = 32.20ft/s^2A =0.001970ft^2D = 0.050094ft0.60inForebay Sizing15%20%Required Forebay Volume = 2,009 cu-ftTo 2,678 cu-ft*15-20% of VmpElevation (ft)Area (sf)Inc. Vol.Volume271.50281-169*6" sediment storage 272.0039400273.00694544544*6" sediment storage not included in MP volume or 274.0010588761420detention calculations for forebay or permanent pool274.7513709112331=∗2.
PB 6 PG 45N/FTOWN OFLOUISBURGPIN # 2806-80-5907DB 600 PG 51PB 6 PG 45N/FEDITH C LUMPKINPIN # 2806-80-4901TRACT 3PB 6 PG 45N/FGREGG RANDOLPHWILLIAMSPIN # 2806-80-0776DB 1076 PG 98PB 2 PG 98N/FFRANKLIN COUNTYPIN # 2806-80-0635DB 2021 PG 641PRF 3 PG SL 23BN/FLARRY GORDONBRAXTONPIN # 2806-70-7677DB 1996 PG 1000N/FCOMMUNITY REALESTATE HOLDING CO.INC.PIN # 2806-70-9466DB 1472 PG 484PB 2 PG 98N/FBERTHA ANN AND KEVING. FULLERPIN # 2806-70-9346DB 806 PG 736PB 2 PG 98N/FROSE D READPIN # 2806-70-9330DB 1215 PG 805PB 2 PG 98N/FDOUGLAS E. NICHOLSONN/FN/FCHRISTOPHER GRAY ANDCATHERINE L. HALESN/FJOLLY HOLDINGS LLC PIN # 2806-80-7292DB 1510 PG 8PB 2006 PG 22WILLIAM J. AND ANN C.WILLIAMSONPIN # 863-70-4654DB 863 PG 555PB 2013 PG 129N/FLARRY GORDONBRAXTONPIN # 2806-60-9841DB 1719 PG 435N/FHOSPITALPIN # 2806-80-5513DB 2021 PG 641PRF 3 PG SL 23BNORTH MAIN STREETSR-1229 VARIABLE WIDTH R/WPB 2013 PG 129
HOSPITAL VIEW STREET40' WIDEPB 6 PG 45SPENCER DRIVE20' WIDEN/FEDITH C LUMPKINPIN # 2806-80-2870TRACT 4PB 6 PG 45OLD RIGHT-OF-WAY LINEPFR 3 PG SL-23B
SS88°25'03"W 434.92'S75°12'24"E 205.56'S20°43'10"W 155.34'S89°26'21"W 218.29'S89°30'14"W 53.70'N20°56'46"E32.88'N20
°
4
1
'
3
8
"
E

1
7
2
.
1
1
'N87°06'24"E 170.73'N74°04'47"E

467
.82
'S74°22'07"W

471
.86
'S15°23'19"E 13.60'N89°13'44"W 66.54'N12°10'11"E 70.93'N18°30'23"E 216.88'S89°55'08"E 51.59'N20°26'08"E 213.34'RECORDED AS 205.62'RECORDED AS 53.65'RECORDED AS 218.33'RECORDED AS 213.43'RECORDED AS 155.40'
REC
O
R
D
E
D

A
S

1
7
2
.
1
2
'RECORDED AS 170.72'RECORDED AS
467
.82
'RECORDED AS
471
.52
'RECORDED AS 434.84'RECORDED AS 13.60'RECORDED AS 66.54'RECORDED AS 71.00'RECORDED AS 216.48'RECORDED AS 51.91'RECORDED AS 32.19'SSSSSSSSSDG295
300
29829028
5
284283282281274275277280282
285
285290
293292287
2
9
6
2
9
3291289287
292288
289292294301 300298295 287288303305SUB-BASIN 2 (SOUTHWEST)IMP. = 0.30 ACPERV. = 1.98 ACEXISTINGDRAINAGE AREAMAP0GRAPHIC SCALE6012030NSUB-BASIN 3 (SOUTH)IMP. = 0.19 ACPERV. = 0.59 ACSUB-BASIN 1 (WEST)IMP. = 1.08 ACPERV. = 0.94 AC
PROPOSED BUILDINGEXPANSION20-BED BHUF.F.E. = 302.70'F.F.E. = 292.70'STAIRCASEF.F.E. = 290.70'STAIRCASEPB 6 PG 45N/FTOWN OFLOUISBURGPIN # 2806-80-5907DB 600 PG 51PB 6 PG 45N/FEDITH C LUMPKINPIN # 2806-80-4901TRACT 3PB 6 PG 45N/FGREGG RANDOLPHWILLIAMSPIN # 2806-80-0776DB 1076 PG 98PB 2 PG 98N/FFRANKLIN COUNTYPIN # 2806-80-0635DB 2021 PG 641PRF 3 PG SL 23BN/FLARRY GORDONBRAXTONPIN # 2806-70-7677DB 1996 PG 1000N/FCOMMUNITY REALESTATE HOLDING CO.INC.PIN # 2806-70-9466DB 1472 PG 484PB 2 PG 98N/FBERTHA ANN AND KEVING. FULLERPIN # 2806-70-9346DB 806 PG 736PB 2 PG 98N/FROSE D READPIN # 2806-70-9330DB 1215 PG 805PB 2 PG 98N/FDOUGLAS E. NICHOLSONN/FN/FCHRISTOPHER GRAY ANDCATHERINE L. HALESN/FJOLLY HOLDINGS LLC PIN # 2806-80-7292DB 1510 PG 8PB 2006 PG 22WILLIAM J. AND ANN C.WILLIAMSONPIN # 863-70-4654DB 863 PG 555PB 2013 PG 129N/FLARRY GORDONBRAXTONPIN # 2806-60-9841DB 1719 PG 435N/FHOSPITALPIN # 2806-80-5513DB 2021 PG 641PRF 3 PG SL 23BNORTH MAIN STREETSR-1229 VARIABLE WIDTH R/WPB 2013 PG 129
HOSPITAL VIEW STREET40' WIDEPB 6 PG 45SPENCER DRIVE20' WIDEN/FEDITH C LUMPKINPIN # 2806-80-2870TRACT 4PB 6 PG 45OLD RIGHT-OF-WAY LINEPFR 3 PG SL-23B
SS88°25'03"W 434.92'S75°12'24"E 205.56'S20°43'10"W 155.34'S89°26'21"W 218.29'S89°30'14"W 53.70'N20°56'46"E32.88'N20
°
4
1
'
3
8
"
E

1
7
2
.
1
1
'N87°06'24"E 170.73'N74°04'47"E

467
.82
'S74°22'07"W

471
.86
'S15°23'19"E 13.60'N89°13'44"W 66.54'N12°10'11"E 70.93'N18°30'23"E 216.88'S89°55'08"E 51.59'N20°26'08"E 213.34'RECORDED AS 205.62'RECORDED AS 53.65'RECORDED AS 218.33'RECORDED AS 213.43'RECORDED AS 155.40'
REC
O
R
D
E
D

A
S

1
7
2
.
1
2
'RECORDED AS 170.72'RECORDED AS
467
.82
'RECORDED AS
471
.52
'RECORDED AS 434.84'RECORDED AS 13.60'RECORDED AS 66.54'RECORDED AS 71.00'RECORDED AS 216.48'RECORDED AS 51.91'RECORDED AS 32.19'SSSSSSSSSDG295
300
29829028
5
284283282281274275277280282
285
285290
293292287
2
9
6
2
9
3291289287
292288
289292294301 300298295 287288303305SUB-BASIN 2 (SOUTHWEST)TO WET PONDIMP. = 1.53 ACPERV. = 1.21 ACPROPOSEDDRAINAGE AREAMAP0GRAPHIC SCALE6012030NSUB-BASIN 3 (SOUTH)PERV. = 0.02 ACSUB-BASIN 1 (WEST)IMP. = 0.85 ACPERV. = 1.06 ACSUB-BASIN 2 (SOUTHWEST)BYPASSPERV. = 0.42 AC
Hydrograph Return Period Recap
1
Hyd. Hydrograph Inflow Peak Outflow (cfs)Hydrograph
No. type hyd(s)Description
(origin) 1-yr 2-yr 3-yr 5-yr 10-yr 25-yr 50-yr 100-yr
1 SCS Runoff ------ 5.116 6.817 ------- ------- 11.55 14.49 16.88 19.35 West(SB1)-Pre
2 SCS Runoff ------ 3.051 4.572 ------- ------- 9.172 12.30 14.91 17.66 Southwest(SB2)-Pre
3 SCS Runoff ------ 1.256 1.811 ------- ------- 3.471 4.574 5.485 6.436 South(SB3)-Pre
4 SCS Runoff ------ 4.204 5.734 ------- ------- 10.13 12.91 15.18 17.52 West(SB1)-Post
5 SCS Runoff ------ 6.940 9.246 ------- ------- 15.66 19.66 22.90 26.24 Southwest(SB2)-Pond
6 SCS Runoff ------ 0.420 0.673 ------- ------- 1.465 2.003 2.463 2.957 Southwest(SB2)-Bypass Post
7 SCS Runoff ------ 0.020 0.032 ------- ------- 0.070 0.095 0.117 0.141 South(SB3)-Post
8 Reservoir 5 0.227 0.759 ------- ------- 5.173 8.167 10.02 11.41 SW to Pond
9 Combine 6, 8 0.420 0.829 ------- ------- 5.846 9.350 11.67 13.46 Southwest Post Combined
Proj. file: 2018-10-05_Detention Calcs.gpw Monday, 10 / 8 / 2018
Hydraflow Hydrographs Extension for AutoCAD® Civil 3D® 2016 by Autodesk, Inc. v11
Hydrograph Report
Hydraflow Hydrographs Extension for AutoCAD® Civil 3D® 2016 by Autodesk, Inc. v11 Monday, 10 / 8 / 2018
Hyd. No. 1
West(SB1)-Pre
Hydrograph type = SCS Runoff Peak discharge = 5.116 cfs
Storm frequency = 1 yrs Time to peak = 716 min
Time interval = 2 min Hyd. volume = 10,343 cuft
Drainage area = 2.020 ac Curve number = 85*
Basin Slope = 0.0 % Hydraulic length = 0 ft
Tc method = User Time of conc. (Tc) = 5.00 min
Total precip. = 2.90 in Distribution = Type II
Storm duration = 24 hrs Shape factor = 484
* Composite (Area/CN) = [(1.080 x 98) + (0.940 x 69)] / 2.020
2
0 120 240 360 480 600 720 840 960 1080 1200 1320 1440
Q (cfs)
0.00 0.00
1.00 1.00
2.00 2.00
3.00 3.00
4.00 4.00
5.00 5.00
6.00 6.00
Q (cfs)
Time (min)
West(SB1)-Pre
Hyd. No. 1 -- 1 Year
Hyd No. 1
Hydrograph Report
Hydraflow Hydrographs Extension for AutoCAD® Civil 3D® 2016 by Autodesk, Inc. v11 Monday, 10 / 8 / 2018
Hyd. No. 2
Southwest(SB2)-Pre
Hydrograph type = SCS Runoff Peak discharge = 3.051 cfs
Storm frequency = 1 yrs Time to peak = 718 min
Time interval = 2 min Hyd. volume = 6,180 cuft
Drainage area = 2.280 ac Curve number = 73*
Basin Slope = 0.0 % Hydraulic length = 0 ft
Tc method = User Time of conc. (Tc) = 5.00 min
Total precip. = 2.90 in Distribution = Type II
Storm duration = 24 hrs Shape factor = 484
* Composite (Area/CN) = [(0.300 x 98) + (1.980 x 69)] / 2.280
3
0 120 240 360 480 600 720 840 960 1080 1200 1320 1440 1560
Q (cfs)
0.00 0.00
1.00 1.00
2.00 2.00
3.00 3.00
4.00 4.00
Q (cfs)
Time (min)
Southwest(SB2)-Pre
Hyd. No. 2 -- 1 Year
Hyd No. 2
Hydrograph Report
Hydraflow Hydrographs Extension for AutoCAD® Civil 3D® 2016 by Autodesk, Inc. v11 Monday, 10 / 8 / 2018
Hyd. No. 3
South(SB3)-Pre
Hydrograph type = SCS Runoff Peak discharge = 1.256 cfs
Storm frequency = 1 yrs Time to peak = 718 min
Time interval = 2 min Hyd. volume = 2,517 cuft
Drainage area = 0.780 ac Curve number = 76*
Basin Slope = 0.0 % Hydraulic length = 0 ft
Tc method = User Time of conc. (Tc) = 5.00 min
Total precip. = 2.90 in Distribution = Type II
Storm duration = 24 hrs Shape factor = 484
* Composite (Area/CN) = [(0.190 x 98) + (0.590 x 69)] / 0.780
4
0 120 240 360 480 600 720 840 960 1080 1200 1320 1440 1560
Q (cfs)
0.00 0.00
1.00 1.00
2.00 2.00
Q (cfs)
Time (min)
South(SB3)-Pre
Hyd. No. 3 -- 1 Year
Hyd No. 3
Hydrograph Report
Hydraflow Hydrographs Extension for AutoCAD® Civil 3D® 2016 by Autodesk, Inc. v11 Monday, 10 / 8 / 2018
Hyd. No. 4
West(SB1)-Post
Hydrograph type = SCS Runoff Peak discharge = 4.204 cfs
Storm frequency = 1 yrs Time to peak = 718 min
Time interval = 2 min Hyd. volume = 8,455 cuft
Drainage area = 1.910 ac Curve number = 82*
Basin Slope = 0.0 % Hydraulic length = 0 ft
Tc method = User Time of conc. (Tc) = 5.00 min
Total precip. = 2.90 in Distribution = Type II
Storm duration = 24 hrs Shape factor = 484
* Composite (Area/CN) = [(0.850 x 98) + (1.060 x 69)] / 1.910
5
0 120 240 360 480 600 720 840 960 1080 1200 1320 1440 1560
Q (cfs)
0.00 0.00
1.00 1.00
2.00 2.00
3.00 3.00
4.00 4.00
5.00 5.00
Q (cfs)
Time (min)
West(SB1)-Post
Hyd. No. 4 -- 1 Year
Hyd No. 4
Hydrograph Report
Hydraflow Hydrographs Extension for AutoCAD® Civil 3D® 2016 by Autodesk, Inc. v11 Monday, 10 / 8 / 2018
Hyd. No. 5
Southwest(SB2)-Pond
Hydrograph type = SCS Runoff Peak discharge = 6.940 cfs
Storm frequency = 1 yrs Time to peak = 716 min
Time interval = 2 min Hyd. volume = 14,030 cuft
Drainage area = 2.740 ac Curve number = 85*
Basin Slope = 0.0 % Hydraulic length = 0 ft
Tc method = User Time of conc. (Tc) = 5.00 min
Total precip. = 2.90 in Distribution = Type II
Storm duration = 24 hrs Shape factor = 484
* Composite (Area/CN) = [(1.530 x 98) + (1.210 x 69)] / 2.740
6
0 120 240 360 480 600 720 840 960 1080 1200 1320 1440
Q (cfs)
0.00 0.00
1.00 1.00
2.00 2.00
3.00 3.00
4.00 4.00
5.00 5.00
6.00 6.00
7.00 7.00
Q (cfs)
Time (min)
Southwest(SB2)-Pond
Hyd. No. 5 -- 1 Year
Hyd No. 5
Hydrograph Report
Hydraflow Hydrographs Extension for AutoCAD® Civil 3D® 2016 by Autodesk, Inc. v11 Monday, 10 / 8 / 2018
Hyd. No. 6
Southwest(SB2)-Bypass Post
Hydrograph type = SCS Runoff Peak discharge = 0.420 cfs
Storm frequency = 1 yrs Time to peak = 718 min
Time interval = 2 min Hyd. volume = 882 cuft
Drainage area = 0.420 ac Curve number = 69*
Basin Slope = 0.0 % Hydraulic length = 0 ft
Tc method = User Time of conc. (Tc) = 5.00 min
Total precip. = 2.90 in Distribution = Type II
Storm duration = 24 hrs Shape factor = 484
* Composite (Area/CN) = + (0.420 x 69)] / 0.420
7
0 120 240 360 480 600 720 840 960 1080 1200 1320 1440 1560
Q (cfs)
0.00 0.00
0.05 0.05
0.10 0.10
0.15 0.15
0.20 0.20
0.25 0.25
0.30 0.30
0.35 0.35
0.40 0.40
0.45 0.45
0.50 0.50
Q (cfs)
Time (min)
Southwest(SB2)-Bypass Post
Hyd. No. 6 -- 1 Year
Hyd No. 6
Hydrograph Report
Hydraflow Hydrographs Extension for AutoCAD® Civil 3D® 2016 by Autodesk, Inc. v11 Monday, 10 / 8 / 2018
Hyd. No. 7
South(SB3)-Post
Hydrograph type = SCS Runoff Peak discharge = 0.020 cfs
Storm frequency = 1 yrs Time to peak = 718 min
Time interval = 2 min Hyd. volume = 42 cuft
Drainage area = 0.020 ac Curve number = 69*
Basin Slope = 0.0 % Hydraulic length = 0 ft
Tc method = User Time of conc. (Tc) = 5.00 min
Total precip. = 2.90 in Distribution = Type II
Storm duration = 24 hrs Shape factor = 484
* Composite (Area/CN) = + (0.040 x 69)] / 0.020
8
0 120 240 360 480 600 720 840 960 1080 1200 1320 1440 1560
Q (cfs)
0.00 0.00
0.01 0.01
0.02 0.02
0.03 0.03
0.04 0.04
0.05 0.05
0.06 0.06
0.07 0.07
0.08 0.08
0.09 0.09
0.10 0.10
Q (cfs)
Time (min)
South(SB3)-Post
Hyd. No. 7 -- 1 Year
Hyd No. 7
Hydrograph Report
Hydraflow Hydrographs Extension for AutoCAD® Civil 3D® 2016 by Autodesk, Inc. v11 Monday, 10 / 8 / 2018
Hyd. No. 8
SW to Pond
Hydrograph type = Reservoir Peak discharge = 0.227 cfs
Storm frequency = 1 yrs Time to peak = 838 min
Time interval = 2 min Hyd. volume = 5,743 cuft
Inflow hyd. No. = 5 - Southwest(SB2)-Pond Max. Elevation = 276.10 ft
Reservoir name = Wet Pond Max. Storage = 9,191 cuft
Storage Indication method used.
9
0 120 240 360 480 600 720 840 960 1080 1200 1320 1440 1560 1680 1800
Q (cfs)
0.00 0.00
1.00 1.00
2.00 2.00
3.00 3.00
4.00 4.00
5.00 5.00
6.00 6.00
7.00 7.00
Q (cfs)
Time (min)
SW to Pond
Hyd. No. 8 -- 1 Year
Hyd No. 8 Hyd No. 5 Total storage used = 9,191 cuft
Pond Report 10
Hydraflow Hydrographs Extension for AutoCAD® Civil 3D® 2016 by Autodesk, Inc. v11 Monday, 10 / 8 / 2018
Pond No. 1 - Wet Pond
Pond Data
Contours -User-defined contour areas. Conic method used for volume calculation. Begining Elevation = 274.75 ft
Stage / Storage Table
Stage (ft) Elevation (ft) Contour area (sqft) Incr. Storage (cuft) Total storage (cuft)
0.00 274.75 4,123 0 0
0.25 275.00 5,978 1,255 1,255
1.25 276.00 8,134 7,028 8,283
2.25 277.00 9,297 8,708 16,991
3.25 278.00 10,517 9,900 26,891
4.25 279.00 11,793 11,148 38,039
Culvert / Orifice Structures Weir Structures
[A] [B] [C] [PrfRsr] [A] [B] [C] [D]
Rise (in)= 18.00 0.05 0.00 0.00
Span (in)= 18.00 0.05 0.00 0.00
No. Barrels = 1 1 0 0
Invert El. (ft)= 274.50 274.75 0.00 0.00
Length (ft)= 14.00 0.00 0.00 0.00
Slope (%)= 2.14 0.00 0.00 n/a
N-Value = .013 .013 .013 n/a
Orifice Coeff.= 0.60 0.60 0.60 0.60
Multi-Stage = n/a Yes No No
Crest Len (ft)= 2.00 0.00 0.00 0.00
Crest El. (ft)= 276.00 0.00 0.00 0.00
Weir Coeff.= 3.33 3.33 3.33 3.33
Weir Type = Rect --- --- ---
Multi-Stage = Yes No No No
Exfil.(in/hr)= 0.000 (by Contour)
TW Elev. (ft)= 0.00
Note: Culvert/Orifice outflows are analyzed under inlet (ic) and outlet (oc) control. Weir risers checked for orifice conditions (ic) and submergence (s).
0.00 2.00 4.00 6.00 8.00 10.00 12.00 14.00 16.00
Stage (ft)
0.00 274.75
1.00 275.75
2.00 276.75
3.00 277.75
4.00 278.75
5.00 279.75
Elev (ft)
Discharge (cfs)
Stage / Discharge
Total Q
Hydrograph Report
Hydraflow Hydrographs Extension for AutoCAD® Civil 3D® 2016 by Autodesk, Inc. v11 Monday, 10 / 8 / 2018
Hyd. No. 9
Southwest Post Combined
Hydrograph type = Combine Peak discharge = 0.420 cfs
Storm frequency = 1 yrs Time to peak = 718 min
Time interval = 2 min Hyd. volume = 6,625 cuft
Inflow hyds. = 6, 8 Contrib. drain. area = 0.420 ac
11
0 120 240 360 480 600 720 840 960 1080 1200 1320 1440 1560 1680
Q (cfs)
0.00 0.00
0.05 0.05
0.10 0.10
0.15 0.15
0.20 0.20
0.25 0.25
0.30 0.30
0.35 0.35
0.40 0.40
0.45 0.45
0.50 0.50
Q (cfs)
Time (min)
Southwest Post Combined
Hyd. No. 9 -- 1 Year
Hyd No. 9 Hyd No. 6 Hyd No. 8
Hydrograph Report
Hydraflow Hydrographs Extension for AutoCAD® Civil 3D® 2016 by Autodesk, Inc. v11 Monday, 10 / 8 / 2018
Hyd. No. 1
West(SB1)-Pre
Hydrograph type = SCS Runoff Peak discharge = 6.817 cfs
Storm frequency = 2 yrs Time to peak = 716 min
Time interval = 2 min Hyd. volume = 13,861 cuft
Drainage area = 2.020 ac Curve number = 85*
Basin Slope = 0.0 % Hydraulic length = 0 ft
Tc method = User Time of conc. (Tc) = 5.00 min
Total precip. = 3.50 in Distribution = Type II
Storm duration = 24 hrs Shape factor = 484
* Composite (Area/CN) = [(1.080 x 98) + (0.940 x 69)] / 2.020
12
0 120 240 360 480 600 720 840 960 1080 1200 1320 1440
Q (cfs)
0.00 0.00
1.00 1.00
2.00 2.00
3.00 3.00
4.00 4.00
5.00 5.00
6.00 6.00
7.00 7.00
Q (cfs)
Time (min)
West(SB1)-Pre
Hyd. No. 1 -- 2 Year
Hyd No. 1
Hydrograph Report
Hydraflow Hydrographs Extension for AutoCAD® Civil 3D® 2016 by Autodesk, Inc. v11 Monday, 10 / 8 / 2018
Hyd. No. 2
Southwest(SB2)-Pre
Hydrograph type = SCS Runoff Peak discharge = 4.572 cfs
Storm frequency = 2 yrs Time to peak = 718 min
Time interval = 2 min Hyd. volume = 9,153 cuft
Drainage area = 2.280 ac Curve number = 73*
Basin Slope = 0.0 % Hydraulic length = 0 ft
Tc method = User Time of conc. (Tc) = 5.00 min
Total precip. = 3.50 in Distribution = Type II
Storm duration = 24 hrs Shape factor = 484
* Composite (Area/CN) = [(0.300 x 98) + (1.980 x 69)] / 2.280
13
0 120 240 360 480 600 720 840 960 1080 1200 1320 1440 1560
Q (cfs)
0.00 0.00
1.00 1.00
2.00 2.00
3.00 3.00
4.00 4.00
5.00 5.00
Q (cfs)
Time (min)
Southwest(SB2)-Pre
Hyd. No. 2 -- 2 Year
Hyd No. 2
Hydrograph Report
Hydraflow Hydrographs Extension for AutoCAD® Civil 3D® 2016 by Autodesk, Inc. v11 Monday, 10 / 8 / 2018
Hyd. No. 3
South(SB3)-Pre
Hydrograph type = SCS Runoff Peak discharge = 1.811 cfs
Storm frequency = 2 yrs Time to peak = 718 min
Time interval = 2 min Hyd. volume = 3,624 cuft
Drainage area = 0.780 ac Curve number = 76*
Basin Slope = 0.0 % Hydraulic length = 0 ft
Tc method = User Time of conc. (Tc) = 5.00 min
Total precip. = 3.50 in Distribution = Type II
Storm duration = 24 hrs Shape factor = 484
* Composite (Area/CN) = [(0.190 x 98) + (0.590 x 69)] / 0.780
14
0 120 240 360 480 600 720 840 960 1080 1200 1320 1440 1560
Q (cfs)
0.00 0.00
1.00 1.00
2.00 2.00
Q (cfs)
Time (min)
South(SB3)-Pre
Hyd. No. 3 -- 2 Year
Hyd No. 3
Hydrograph Report
Hydraflow Hydrographs Extension for AutoCAD® Civil 3D® 2016 by Autodesk, Inc. v11 Monday, 10 / 8 / 2018
Hyd. No. 4
West(SB1)-Post
Hydrograph type = SCS Runoff Peak discharge = 5.734 cfs
Storm frequency = 2 yrs Time to peak = 716 min
Time interval = 2 min Hyd. volume = 11,587 cuft
Drainage area = 1.910 ac Curve number = 82*
Basin Slope = 0.0 % Hydraulic length = 0 ft
Tc method = User Time of conc. (Tc) = 5.00 min
Total precip. = 3.50 in Distribution = Type II
Storm duration = 24 hrs Shape factor = 484
* Composite (Area/CN) = [(0.850 x 98) + (1.060 x 69)] / 1.910
15
0 120 240 360 480 600 720 840 960 1080 1200 1320 1440 1560
Q (cfs)
0.00 0.00
1.00 1.00
2.00 2.00
3.00 3.00
4.00 4.00
5.00 5.00
6.00 6.00
Q (cfs)
Time (min)
West(SB1)-Post
Hyd. No. 4 -- 2 Year
Hyd No. 4
Hydrograph Report
Hydraflow Hydrographs Extension for AutoCAD® Civil 3D® 2016 by Autodesk, Inc. v11 Monday, 10 / 8 / 2018
Hyd. No. 5
Southwest(SB2)-Pond
Hydrograph type = SCS Runoff Peak discharge = 9.246 cfs
Storm frequency = 2 yrs Time to peak = 716 min
Time interval = 2 min Hyd. volume = 18,802 cuft
Drainage area = 2.740 ac Curve number = 85*
Basin Slope = 0.0 % Hydraulic length = 0 ft
Tc method = User Time of conc. (Tc) = 5.00 min
Total precip. = 3.50 in Distribution = Type II
Storm duration = 24 hrs Shape factor = 484
* Composite (Area/CN) = [(1.530 x 98) + (1.210 x 69)] / 2.740
16
0 120 240 360 480 600 720 840 960 1080 1200 1320 1440
Q (cfs)
0.00 0.00
2.00 2.00
4.00 4.00
6.00 6.00
8.00 8.00
10.00 10.00
Q (cfs)
Time (min)
Southwest(SB2)-Pond
Hyd. No. 5 -- 2 Year
Hyd No. 5
Hydrograph Report
Hydraflow Hydrographs Extension for AutoCAD® Civil 3D® 2016 by Autodesk, Inc. v11 Monday, 10 / 8 / 2018
Hyd. No. 6
Southwest(SB2)-Bypass Post
Hydrograph type = SCS Runoff Peak discharge = 0.673 cfs
Storm frequency = 2 yrs Time to peak = 718 min
Time interval = 2 min Hyd. volume = 1,363 cuft
Drainage area = 0.420 ac Curve number = 69*
Basin Slope = 0.0 % Hydraulic length = 0 ft
Tc method = User Time of conc. (Tc) = 5.00 min
Total precip. = 3.50 in Distribution = Type II
Storm duration = 24 hrs Shape factor = 484
* Composite (Area/CN) = + (0.420 x 69)] / 0.420
17
0 120 240 360 480 600 720 840 960 1080 1200 1320 1440 1560
Q (cfs)
0.00 0.00
0.10 0.10
0.20 0.20
0.30 0.30
0.40 0.40
0.50 0.50
0.60 0.60
0.70 0.70
0.80 0.80
0.90 0.90
1.00 1.00
Q (cfs)
Time (min)
Southwest(SB2)-Bypass Post
Hyd. No. 6 -- 2 Year
Hyd No. 6
Hydrograph Report
Hydraflow Hydrographs Extension for AutoCAD® Civil 3D® 2016 by Autodesk, Inc. v11 Monday, 10 / 8 / 2018
Hyd. No. 7
South(SB3)-Post
Hydrograph type = SCS Runoff Peak discharge = 0.032 cfs
Storm frequency = 2 yrs Time to peak = 718 min
Time interval = 2 min Hyd. volume = 65 cuft
Drainage area = 0.020 ac Curve number = 69*
Basin Slope = 0.0 % Hydraulic length = 0 ft
Tc method = User Time of conc. (Tc) = 5.00 min
Total precip. = 3.50 in Distribution = Type II
Storm duration = 24 hrs Shape factor = 484
* Composite (Area/CN) = + (0.040 x 69)] / 0.020
18
0 120 240 360 480 600 720 840 960 1080 1200 1320 1440 1560
Q (cfs)
0.00 0.00
0.01 0.01
0.02 0.02
0.03 0.03
0.04 0.04
0.05 0.05
0.06 0.06
0.07 0.07
0.08 0.08
0.09 0.09
0.10 0.10
Q (cfs)
Time (min)
South(SB3)-Post
Hyd. No. 7 -- 2 Year
Hyd No. 7
Hydrograph Report
Hydraflow Hydrographs Extension for AutoCAD® Civil 3D® 2016 by Autodesk, Inc. v11 Monday, 10 / 8 / 2018
Hyd. No. 8
SW to Pond
Hydrograph type = Reservoir Peak discharge = 0.759 cfs
Storm frequency = 2 yrs Time to peak = 750 min
Time interval = 2 min Hyd. volume = 10,515 cuft
Inflow hyd. No. = 5 - Southwest(SB2)-Pond Max. Elevation = 276.23 ft
Reservoir name = Wet Pond Max. Storage = 10,310 cuft
Storage Indication method used.
19
0 120 240 360 480 600 720 840 960 1080 1200 1320 1440 1560 1680
Q (cfs)
0.00 0.00
2.00 2.00
4.00 4.00
6.00 6.00
8.00 8.00
10.00 10.00
Q (cfs)
Time (min)
SW to Pond
Hyd. No. 8 -- 2 Year
Hyd No. 8 Hyd No. 5 Total storage used = 10,310 cuft
Hydrograph Report
Hydraflow Hydrographs Extension for AutoCAD® Civil 3D® 2016 by Autodesk, Inc. v11 Monday, 10 / 8 / 2018
Hyd. No. 9
Southwest Post Combined
Hydrograph type = Combine Peak discharge = 0.829 cfs
Storm frequency = 2 yrs Time to peak = 746 min
Time interval = 2 min Hyd. volume = 11,879 cuft
Inflow hyds. = 6, 8 Contrib. drain. area = 0.420 ac
20
0 120 240 360 480 600 720 840 960 1080 1200 1320 1440 1560 1680
Q (cfs)
0.00 0.00
0.10 0.10
0.20 0.20
0.30 0.30
0.40 0.40
0.50 0.50
0.60 0.60
0.70 0.70
0.80 0.80
0.90 0.90
1.00 1.00
Q (cfs)
Time (min)
Southwest Post Combined
Hyd. No. 9 -- 2 Year
Hyd No. 9 Hyd No. 6 Hyd No. 8
Hydrograph Report
Hydraflow Hydrographs Extension for AutoCAD® Civil 3D® 2016 by Autodesk, Inc. v11 Monday, 10 / 8 / 2018
Hyd. No. 1
West(SB1)-Pre
Hydrograph type = SCS Runoff Peak discharge = 11.55 cfs
Storm frequency = 10 yrs Time to peak = 716 min
Time interval = 2 min Hyd. volume = 23,980 cuft
Drainage area = 2.020 ac Curve number = 85*
Basin Slope = 0.0 % Hydraulic length = 0 ft
Tc method = User Time of conc. (Tc) = 5.00 min
Total precip. = 5.13 in Distribution = Type II
Storm duration = 24 hrs Shape factor = 484
* Composite (Area/CN) = [(1.080 x 98) + (0.940 x 69)] / 2.020
21
0 120 240 360 480 600 720 840 960 1080 1200 1320
Q (cfs)
0.00 0.00
2.00 2.00
4.00 4.00
6.00 6.00
8.00 8.00
10.00 10.00
12.00 12.00
Q (cfs)
Time (min)
West(SB1)-Pre
Hyd. No. 1 -- 10 Year
Hyd No. 1
Hydrograph Report
Hydraflow Hydrographs Extension for AutoCAD® Civil 3D® 2016 by Autodesk, Inc. v11 Monday, 10 / 8 / 2018
Hyd. No. 2
Southwest(SB2)-Pre
Hydrograph type = SCS Runoff Peak discharge = 9.172 cfs
Storm frequency = 10 yrs Time to peak = 718 min
Time interval = 2 min Hyd. volume = 18,489 cuft
Drainage area = 2.280 ac Curve number = 73*
Basin Slope = 0.0 % Hydraulic length = 0 ft
Tc method = User Time of conc. (Tc) = 5.00 min
Total precip. = 5.13 in Distribution = Type II
Storm duration = 24 hrs Shape factor = 484
* Composite (Area/CN) = [(0.300 x 98) + (1.980 x 69)] / 2.280
22
0 120 240 360 480 600 720 840 960 1080 1200 1320 1440 1560
Q (cfs)
0.00 0.00
2.00 2.00
4.00 4.00
6.00 6.00
8.00 8.00
10.00 10.00
Q (cfs)
Time (min)
Southwest(SB2)-Pre
Hyd. No. 2 -- 10 Year
Hyd No. 2
Hydrograph Report
Hydraflow Hydrographs Extension for AutoCAD® Civil 3D® 2016 by Autodesk, Inc. v11 Monday, 10 / 8 / 2018
Hyd. No. 3
South(SB3)-Pre
Hydrograph type = SCS Runoff Peak discharge = 3.471 cfs
Storm frequency = 10 yrs Time to peak = 716 min
Time interval = 2 min Hyd. volume = 7,016 cuft
Drainage area = 0.780 ac Curve number = 76*
Basin Slope = 0.0 % Hydraulic length = 0 ft
Tc method = User Time of conc. (Tc) = 5.00 min
Total precip. = 5.13 in Distribution = Type II
Storm duration = 24 hrs Shape factor = 484
* Composite (Area/CN) = [(0.190 x 98) + (0.590 x 69)] / 0.780
23
0 120 240 360 480 600 720 840 960 1080 1200 1320 1440
Q (cfs)
0.00 0.00
1.00 1.00
2.00 2.00
3.00 3.00
4.00 4.00
Q (cfs)
Time (min)
South(SB3)-Pre
Hyd. No. 3 -- 10 Year
Hyd No. 3
Hydrograph Report
Hydraflow Hydrographs Extension for AutoCAD® Civil 3D® 2016 by Autodesk, Inc. v11 Monday, 10 / 8 / 2018
Hyd. No. 4
West(SB1)-Post
Hydrograph type = SCS Runoff Peak discharge = 10.13 cfs
Storm frequency = 10 yrs Time to peak = 716 min
Time interval = 2 min Hyd. volume = 20,771 cuft
Drainage area = 1.910 ac Curve number = 82*
Basin Slope = 0.0 % Hydraulic length = 0 ft
Tc method = User Time of conc. (Tc) = 5.00 min
Total precip. = 5.13 in Distribution = Type II
Storm duration = 24 hrs Shape factor = 484
* Composite (Area/CN) = [(0.850 x 98) + (1.060 x 69)] / 1.910
24
0 120 240 360 480 600 720 840 960 1080 1200 1320
Q (cfs)
0.00 0.00
2.00 2.00
4.00 4.00
6.00 6.00
8.00 8.00
10.00 10.00
12.00 12.00
Q (cfs)
Time (min)
West(SB1)-Post
Hyd. No. 4 -- 10 Year
Hyd No. 4
Hydrograph Report
Hydraflow Hydrographs Extension for AutoCAD® Civil 3D® 2016 by Autodesk, Inc. v11 Monday, 10 / 8 / 2018
Hyd. No. 5
Southwest(SB2)-Pond
Hydrograph type = SCS Runoff Peak discharge = 15.66 cfs
Storm frequency = 10 yrs Time to peak = 716 min
Time interval = 2 min Hyd. volume = 32,528 cuft
Drainage area = 2.740 ac Curve number = 85*
Basin Slope = 0.0 % Hydraulic length = 0 ft
Tc method = User Time of conc. (Tc) = 5.00 min
Total precip. = 5.13 in Distribution = Type II
Storm duration = 24 hrs Shape factor = 484
* Composite (Area/CN) = [(1.530 x 98) + (1.210 x 69)] / 2.740
25
0 120 240 360 480 600 720 840 960 1080 1200 1320
Q (cfs)
0.00 0.00
3.00 3.00
6.00 6.00
9.00 9.00
12.00 12.00
15.00 15.00
18.00 18.00
Q (cfs)
Time (min)
Southwest(SB2)-Pond
Hyd. No. 5 -- 10 Year
Hyd No. 5
Hydrograph Report
Hydraflow Hydrographs Extension for AutoCAD® Civil 3D® 2016 by Autodesk, Inc. v11 Monday, 10 / 8 / 2018
Hyd. No. 6
Southwest(SB2)-Bypass Post
Hydrograph type = SCS Runoff Peak discharge = 1.465 cfs
Storm frequency = 10 yrs Time to peak = 718 min
Time interval = 2 min Hyd. volume = 2,933 cuft
Drainage area = 0.420 ac Curve number = 69*
Basin Slope = 0.0 % Hydraulic length = 0 ft
Tc method = User Time of conc. (Tc) = 5.00 min
Total precip. = 5.13 in Distribution = Type II
Storm duration = 24 hrs Shape factor = 484
* Composite (Area/CN) = + (0.420 x 69)] / 0.420
26
0 120 240 360 480 600 720 840 960 1080 1200 1320 1440 1560
Q (cfs)
0.00 0.00
1.00 1.00
2.00 2.00
Q (cfs)
Time (min)
Southwest(SB2)-Bypass Post
Hyd. No. 6 -- 10 Year
Hyd No. 6
Hydrograph Report
Hydraflow Hydrographs Extension for AutoCAD® Civil 3D® 2016 by Autodesk, Inc. v11 Monday, 10 / 8 / 2018
Hyd. No. 7
South(SB3)-Post
Hydrograph type = SCS Runoff Peak discharge = 0.070 cfs
Storm frequency = 10 yrs Time to peak = 718 min
Time interval = 2 min Hyd. volume = 140 cuft
Drainage area = 0.020 ac Curve number = 69*
Basin Slope = 0.0 % Hydraulic length = 0 ft
Tc method = User Time of conc. (Tc) = 5.00 min
Total precip. = 5.13 in Distribution = Type II
Storm duration = 24 hrs Shape factor = 484
* Composite (Area/CN) = + (0.040 x 69)] / 0.020
27
0 120 240 360 480 600 720 840 960 1080 1200 1320 1440 1560
Q (cfs)
0.00 0.00
0.01 0.01
0.02 0.02
0.03 0.03
0.04 0.04
0.05 0.05
0.06 0.06
0.07 0.07
0.08 0.08
0.09 0.09
0.10 0.10
Q (cfs)
Time (min)
South(SB3)-Post
Hyd. No. 7 -- 10 Year
Hyd No. 7
Hydrograph Report
Hydraflow Hydrographs Extension for AutoCAD® Civil 3D® 2016 by Autodesk, Inc. v11 Monday, 10 / 8 / 2018
Hyd. No. 8
SW to Pond
Hydrograph type = Reservoir Peak discharge = 5.173 cfs
Storm frequency = 10 yrs Time to peak = 724 min
Time interval = 2 min Hyd. volume = 24,241 cuft
Inflow hyd. No. = 5 - Southwest(SB2)-Pond Max. Elevation = 276.85 ft
Reservoir name = Wet Pond Max. Storage = 15,635 cuft
Storage Indication method used.
28
0 120 240 360 480 600 720 840 960 1080 1200 1320 1440 1560
Q (cfs)
0.00 0.00
3.00 3.00
6.00 6.00
9.00 9.00
12.00 12.00
15.00 15.00
18.00 18.00
Q (cfs)
Time (min)
SW to Pond
Hyd. No. 8 -- 10 Year
Hyd No. 8 Hyd No. 5 Total storage used = 15,635 cuft
Hydrograph Report
Hydraflow Hydrographs Extension for AutoCAD® Civil 3D® 2016 by Autodesk, Inc. v11 Monday, 10 / 8 / 2018
Hyd. No. 9
Southwest Post Combined
Hydrograph type = Combine Peak discharge = 5.846 cfs
Storm frequency = 10 yrs Time to peak = 722 min
Time interval = 2 min Hyd. volume = 27,174 cuft
Inflow hyds. = 6, 8 Contrib. drain. area = 0.420 ac
29
0 120 240 360 480 600 720 840 960 1080 1200 1320 1440 1560
Q (cfs)
0.00 0.00
1.00 1.00
2.00 2.00
3.00 3.00
4.00 4.00
5.00 5.00
6.00 6.00
Q (cfs)
Time (min)
Southwest Post Combined
Hyd. No. 9 -- 10 Year
Hyd No. 9 Hyd No. 6 Hyd No. 8
Hydrograph Report
Hydraflow Hydrographs Extension for AutoCAD® Civil 3D® 2016 by Autodesk, Inc. v11 Monday, 10 / 8 / 2018
Hyd. No. 1
West(SB1)-Pre
Hydrograph type = SCS Runoff Peak discharge = 14.49 cfs
Storm frequency = 25 yrs Time to peak = 716 min
Time interval = 2 min Hyd. volume = 30,486 cuft
Drainage area = 2.020 ac Curve number = 85*
Basin Slope = 0.0 % Hydraulic length = 0 ft
Tc method = User Time of conc. (Tc) = 5.00 min
Total precip. = 6.14 in Distribution = Type II
Storm duration = 24 hrs Shape factor = 484
* Composite (Area/CN) = [(1.080 x 98) + (0.940 x 69)] / 2.020
30
0 120 240 360 480 600 720 840 960 1080 1200 1320
Q (cfs)
0.00 0.00
3.00 3.00
6.00 6.00
9.00 9.00
12.00 12.00
15.00 15.00
Q (cfs)
Time (min)
West(SB1)-Pre
Hyd. No. 1 -- 25 Year
Hyd No. 1
Hydrograph Report
Hydraflow Hydrographs Extension for AutoCAD® Civil 3D® 2016 by Autodesk, Inc. v11 Monday, 10 / 8 / 2018
Hyd. No. 2
Southwest(SB2)-Pre
Hydrograph type = SCS Runoff Peak discharge = 12.30 cfs
Storm frequency = 25 yrs Time to peak = 716 min
Time interval = 2 min Hyd. volume = 24,869 cuft
Drainage area = 2.280 ac Curve number = 73*
Basin Slope = 0.0 % Hydraulic length = 0 ft
Tc method = User Time of conc. (Tc) = 5.00 min
Total precip. = 6.14 in Distribution = Type II
Storm duration = 24 hrs Shape factor = 484
* Composite (Area/CN) = [(0.300 x 98) + (1.980 x 69)] / 2.280
31
0 120 240 360 480 600 720 840 960 1080 1200 1320 1440
Q (cfs)
0.00 0.00
2.00 2.00
4.00 4.00
6.00 6.00
8.00 8.00
10.00 10.00
12.00 12.00
14.00 14.00
Q (cfs)
Time (min)
Southwest(SB2)-Pre
Hyd. No. 2 -- 25 Year
Hyd No. 2
Hydrograph Report
Hydraflow Hydrographs Extension for AutoCAD® Civil 3D® 2016 by Autodesk, Inc. v11 Monday, 10 / 8 / 2018
Hyd. No. 3
South(SB3)-Pre
Hydrograph type = SCS Runoff Peak discharge = 4.574 cfs
Storm frequency = 25 yrs Time to peak = 716 min
Time interval = 2 min Hyd. volume = 9,294 cuft
Drainage area = 0.780 ac Curve number = 76*
Basin Slope = 0.0 % Hydraulic length = 0 ft
Tc method = User Time of conc. (Tc) = 5.00 min
Total precip. = 6.14 in Distribution = Type II
Storm duration = 24 hrs Shape factor = 484
* Composite (Area/CN) = [(0.190 x 98) + (0.590 x 69)] / 0.780
32
0 120 240 360 480 600 720 840 960 1080 1200 1320 1440
Q (cfs)
0.00 0.00
1.00 1.00
2.00 2.00
3.00 3.00
4.00 4.00
5.00 5.00
Q (cfs)
Time (min)
South(SB3)-Pre
Hyd. No. 3 -- 25 Year
Hyd No. 3
Hydrograph Report
Hydraflow Hydrographs Extension for AutoCAD® Civil 3D® 2016 by Autodesk, Inc. v11 Monday, 10 / 8 / 2018
Hyd. No. 4
West(SB1)-Post
Hydrograph type = SCS Runoff Peak discharge = 12.91 cfs
Storm frequency = 25 yrs Time to peak = 716 min
Time interval = 2 min Hyd. volume = 26,755 cuft
Drainage area = 1.910 ac Curve number = 82*
Basin Slope = 0.0 % Hydraulic length = 0 ft
Tc method = User Time of conc. (Tc) = 5.00 min
Total precip. = 6.14 in Distribution = Type II
Storm duration = 24 hrs Shape factor = 484
* Composite (Area/CN) = [(0.850 x 98) + (1.060 x 69)] / 1.910
33
0 120 240 360 480 600 720 840 960 1080 1200 1320
Q (cfs)
0.00 0.00
2.00 2.00
4.00 4.00
6.00 6.00
8.00 8.00
10.00 10.00
12.00 12.00
14.00 14.00
Q (cfs)
Time (min)
West(SB1)-Post
Hyd. No. 4 -- 25 Year
Hyd No. 4
Hydrograph Report
Hydraflow Hydrographs Extension for AutoCAD® Civil 3D® 2016 by Autodesk, Inc. v11 Monday, 10 / 8 / 2018
Hyd. No. 5
Southwest(SB2)-Pond
Hydrograph type = SCS Runoff Peak discharge = 19.66 cfs
Storm frequency = 25 yrs Time to peak = 716 min
Time interval = 2 min Hyd. volume = 41,352 cuft
Drainage area = 2.740 ac Curve number = 85*
Basin Slope = 0.0 % Hydraulic length = 0 ft
Tc method = User Time of conc. (Tc) = 5.00 min
Total precip. = 6.14 in Distribution = Type II
Storm duration = 24 hrs Shape factor = 484
* Composite (Area/CN) = [(1.530 x 98) + (1.210 x 69)] / 2.740
34
0 120 240 360 480 600 720 840 960 1080 1200 1320
Q (cfs)
0.00 0.00
3.00 3.00
6.00 6.00
9.00 9.00
12.00 12.00
15.00 15.00
18.00 18.00
21.00 21.00
Q (cfs)
Time (min)
Southwest(SB2)-Pond
Hyd. No. 5 -- 25 Year
Hyd No. 5
Hydrograph Report
Hydraflow Hydrographs Extension for AutoCAD® Civil 3D® 2016 by Autodesk, Inc. v11 Monday, 10 / 8 / 2018
Hyd. No. 6
Southwest(SB2)-Bypass Post
Hydrograph type = SCS Runoff Peak discharge = 2.003 cfs
Storm frequency = 25 yrs Time to peak = 718 min
Time interval = 2 min Hyd. volume = 4,034 cuft
Drainage area = 0.420 ac Curve number = 69*
Basin Slope = 0.0 % Hydraulic length = 0 ft
Tc method = User Time of conc. (Tc) = 5.00 min
Total precip. = 6.14 in Distribution = Type II
Storm duration = 24 hrs Shape factor = 484
* Composite (Area/CN) = + (0.420 x 69)] / 0.420
35
0 120 240 360 480 600 720 840 960 1080 1200 1320 1440 1560
Q (cfs)
0.00 0.00
1.00 1.00
2.00 2.00
3.00 3.00
Q (cfs)
Time (min)
Southwest(SB2)-Bypass Post
Hyd. No. 6 -- 25 Year
Hyd No. 6
Hydrograph Report
Hydraflow Hydrographs Extension for AutoCAD® Civil 3D® 2016 by Autodesk, Inc. v11 Monday, 10 / 8 / 2018
Hyd. No. 7
South(SB3)-Post
Hydrograph type = SCS Runoff Peak discharge = 0.095 cfs
Storm frequency = 25 yrs Time to peak = 718 min
Time interval = 2 min Hyd. volume = 192 cuft
Drainage area = 0.020 ac Curve number = 69*
Basin Slope = 0.0 % Hydraulic length = 0 ft
Tc method = User Time of conc. (Tc) = 5.00 min
Total precip. = 6.14 in Distribution = Type II
Storm duration = 24 hrs Shape factor = 484
* Composite (Area/CN) = + (0.040 x 69)] / 0.020
36
0 120 240 360 480 600 720 840 960 1080 1200 1320 1440 1560
Q (cfs)
0.00 0.00
0.01 0.01
0.02 0.02
0.03 0.03
0.04 0.04
0.05 0.05
0.06 0.06
0.07 0.07
0.08 0.08
0.09 0.09
0.10 0.10
Q (cfs)
Time (min)
South(SB3)-Post
Hyd. No. 7 -- 25 Year
Hyd No. 7
Hydrograph Report
Hydraflow Hydrographs Extension for AutoCAD® Civil 3D® 2016 by Autodesk, Inc. v11 Monday, 10 / 8 / 2018
Hyd. No. 8
SW to Pond
Hydrograph type = Reservoir Peak discharge = 8.167 cfs
Storm frequency = 25 yrs Time to peak = 722 min
Time interval = 2 min Hyd. volume = 33,065 cuft
Inflow hyd. No. = 5 - Southwest(SB2)-Pond Max. Elevation = 277.19 ft
Reservoir name = Wet Pond Max. Storage = 18,802 cuft
Storage Indication method used.
37
0 120 240 360 480 600 720 840 960 1080 1200 1320 1440 1560
Q (cfs)
0.00 0.00
3.00 3.00
6.00 6.00
9.00 9.00
12.00 12.00
15.00 15.00
18.00 18.00
21.00 21.00
Q (cfs)
Time (min)
SW to Pond
Hyd. No. 8 -- 25 Year
Hyd No. 8 Hyd No. 5 Total storage used = 18,802 cuft
Hydrograph Report
Hydraflow Hydrographs Extension for AutoCAD® Civil 3D® 2016 by Autodesk, Inc. v11 Monday, 10 / 8 / 2018
Hyd. No. 9
Southwest Post Combined
Hydrograph type = Combine Peak discharge = 9.350 cfs
Storm frequency = 25 yrs Time to peak = 720 min
Time interval = 2 min Hyd. volume = 37,099 cuft
Inflow hyds. = 6, 8 Contrib. drain. area = 0.420 ac
38
0 120 240 360 480 600 720 840 960 1080 1200 1320 1440 1560
Q (cfs)
0.00 0.00
2.00 2.00
4.00 4.00
6.00 6.00
8.00 8.00
10.00 10.00
Q (cfs)
Time (min)
Southwest Post Combined
Hyd. No. 9 -- 25 Year
Hyd No. 9 Hyd No. 6 Hyd No. 8
Hydrograph Report
Hydraflow Hydrographs Extension for AutoCAD® Civil 3D® 2016 by Autodesk, Inc. v11 Monday, 10 / 8 / 2018
Hyd. No. 1
West(SB1)-Pre
Hydrograph type = SCS Runoff Peak discharge = 16.88 cfs
Storm frequency = 50 yrs Time to peak = 716 min
Time interval = 2 min Hyd. volume = 35,845 cuft
Drainage area = 2.020 ac Curve number = 85*
Basin Slope = 0.0 % Hydraulic length = 0 ft
Tc method = User Time of conc. (Tc) = 5.00 min
Total precip. = 6.96 in Distribution = Type II
Storm duration = 24 hrs Shape factor = 484
* Composite (Area/CN) = [(1.080 x 98) + (0.940 x 69)] / 2.020
39
0 120 240 360 480 600 720 840 960 1080 1200
Q (cfs)
0.00 0.00
3.00 3.00
6.00 6.00
9.00 9.00
12.00 12.00
15.00 15.00
18.00 18.00
Q (cfs)
Time (min)
West(SB1)-Pre
Hyd. No. 1 -- 50 Year
Hyd No. 1
Hydrograph Report
Hydraflow Hydrographs Extension for AutoCAD® Civil 3D® 2016 by Autodesk, Inc. v11 Monday, 10 / 8 / 2018
Hyd. No. 2
Southwest(SB2)-Pre
Hydrograph type = SCS Runoff Peak discharge = 14.91 cfs
Storm frequency = 50 yrs Time to peak = 716 min
Time interval = 2 min Hyd. volume = 30,267 cuft
Drainage area = 2.280 ac Curve number = 73*
Basin Slope = 0.0 % Hydraulic length = 0 ft
Tc method = User Time of conc. (Tc) = 5.00 min
Total precip. = 6.96 in Distribution = Type II
Storm duration = 24 hrs Shape factor = 484
* Composite (Area/CN) = [(0.300 x 98) + (1.980 x 69)] / 2.280
40
0 120 240 360 480 600 720 840 960 1080 1200 1320 1440
Q (cfs)
0.00 0.00
3.00 3.00
6.00 6.00
9.00 9.00
12.00 12.00
15.00 15.00
Q (cfs)
Time (min)
Southwest(SB2)-Pre
Hyd. No. 2 -- 50 Year
Hyd No. 2
Hydrograph Report
Hydraflow Hydrographs Extension for AutoCAD® Civil 3D® 2016 by Autodesk, Inc. v11 Monday, 10 / 8 / 2018
Hyd. No. 3
South(SB3)-Pre
Hydrograph type = SCS Runoff Peak discharge = 5.485 cfs
Storm frequency = 50 yrs Time to peak = 716 min
Time interval = 2 min Hyd. volume = 11,206 cuft
Drainage area = 0.780 ac Curve number = 76*
Basin Slope = 0.0 % Hydraulic length = 0 ft
Tc method = User Time of conc. (Tc) = 5.00 min
Total precip. = 6.96 in Distribution = Type II
Storm duration = 24 hrs Shape factor = 484
* Composite (Area/CN) = [(0.190 x 98) + (0.590 x 69)] / 0.780
41
0 120 240 360 480 600 720 840 960 1080 1200 1320
Q (cfs)
0.00 0.00
1.00 1.00
2.00 2.00
3.00 3.00
4.00 4.00
5.00 5.00
6.00 6.00
Q (cfs)
Time (min)
South(SB3)-Pre
Hyd. No. 3 -- 50 Year
Hyd No. 3
Hydrograph Report
Hydraflow Hydrographs Extension for AutoCAD® Civil 3D® 2016 by Autodesk, Inc. v11 Monday, 10 / 8 / 2018
Hyd. No. 4
West(SB1)-Post
Hydrograph type = SCS Runoff Peak discharge = 15.18 cfs
Storm frequency = 50 yrs Time to peak = 716 min
Time interval = 2 min Hyd. volume = 31,711 cuft
Drainage area = 1.910 ac Curve number = 82*
Basin Slope = 0.0 % Hydraulic length = 0 ft
Tc method = User Time of conc. (Tc) = 5.00 min
Total precip. = 6.96 in Distribution = Type II
Storm duration = 24 hrs Shape factor = 484
* Composite (Area/CN) = [(0.850 x 98) + (1.060 x 69)] / 1.910
42
0 120 240 360 480 600 720 840 960 1080 1200 1320
Q (cfs)
0.00 0.00
3.00 3.00
6.00 6.00
9.00 9.00
12.00 12.00
15.00 15.00
18.00 18.00
Q (cfs)
Time (min)
West(SB1)-Post
Hyd. No. 4 -- 50 Year
Hyd No. 4
Hydrograph Report
Hydraflow Hydrographs Extension for AutoCAD® Civil 3D® 2016 by Autodesk, Inc. v11 Monday, 10 / 8 / 2018
Hyd. No. 5
Southwest(SB2)-Pond
Hydrograph type = SCS Runoff Peak discharge = 22.90 cfs
Storm frequency = 50 yrs Time to peak = 716 min
Time interval = 2 min Hyd. volume = 48,621 cuft
Drainage area = 2.740 ac Curve number = 85*
Basin Slope = 0.0 % Hydraulic length = 0 ft
Tc method = User Time of conc. (Tc) = 5.00 min
Total precip. = 6.96 in Distribution = Type II
Storm duration = 24 hrs Shape factor = 484
* Composite (Area/CN) = [(1.530 x 98) + (1.210 x 69)] / 2.740
43
0 120 240 360 480 600 720 840 960 1080 1200
Q (cfs)
0.00 0.00
4.00 4.00
8.00 8.00
12.00 12.00
16.00 16.00
20.00 20.00
24.00 24.00
Q (cfs)
Time (min)
Southwest(SB2)-Pond
Hyd. No. 5 -- 50 Year
Hyd No. 5
Hydrograph Report
Hydraflow Hydrographs Extension for AutoCAD® Civil 3D® 2016 by Autodesk, Inc. v11 Monday, 10 / 8 / 2018
Hyd. No. 6
Southwest(SB2)-Bypass Post
Hydrograph type = SCS Runoff Peak discharge = 2.463 cfs
Storm frequency = 50 yrs Time to peak = 716 min
Time interval = 2 min Hyd. volume = 4,976 cuft
Drainage area = 0.420 ac Curve number = 69*
Basin Slope = 0.0 % Hydraulic length = 0 ft
Tc method = User Time of conc. (Tc) = 5.00 min
Total precip. = 6.96 in Distribution = Type II
Storm duration = 24 hrs Shape factor = 484
* Composite (Area/CN) = + (0.420 x 69)] / 0.420
44
0 120 240 360 480 600 720 840 960 1080 1200 1320 1440 1560
Q (cfs)
0.00 0.00
1.00 1.00
2.00 2.00
3.00 3.00
Q (cfs)
Time (min)
Southwest(SB2)-Bypass Post
Hyd. No. 6 -- 50 Year
Hyd No. 6
Hydrograph Report
Hydraflow Hydrographs Extension for AutoCAD® Civil 3D® 2016 by Autodesk, Inc. v11 Monday, 10 / 8 / 2018
Hyd. No. 7
South(SB3)-Post
Hydrograph type = SCS Runoff Peak discharge = 0.117 cfs
Storm frequency = 50 yrs Time to peak = 716 min
Time interval = 2 min Hyd. volume = 237 cuft
Drainage area = 0.020 ac Curve number = 69*
Basin Slope = 0.0 % Hydraulic length = 0 ft
Tc method = User Time of conc. (Tc) = 5.00 min
Total precip. = 6.96 in Distribution = Type II
Storm duration = 24 hrs Shape factor = 484
* Composite (Area/CN) = + (0.040 x 69)] / 0.020
45
0 120 240 360 480 600 720 840 960 1080 1200 1320 1440 1560
Q (cfs)
0.00 0.00
0.05 0.05
0.10 0.10
0.15 0.15
0.20 0.20
0.25 0.25
0.30 0.30
0.35 0.35
0.40 0.40
0.45 0.45
0.50 0.50
Q (cfs)
Time (min)
South(SB3)-Post
Hyd. No. 7 -- 50 Year
Hyd No. 7
Hydrograph Report
Hydraflow Hydrographs Extension for AutoCAD® Civil 3D® 2016 by Autodesk, Inc. v11 Monday, 10 / 8 / 2018
Hyd. No. 8
SW to Pond
Hydrograph type = Reservoir Peak discharge = 10.02 cfs
Storm frequency = 50 yrs Time to peak = 722 min
Time interval = 2 min Hyd. volume = 40,335 cuft
Inflow hyd. No. = 5 - Southwest(SB2)-Pond Max. Elevation = 277.44 ft
Reservoir name = Wet Pond Max. Storage = 21,325 cuft
Storage Indication method used.
46
0 120 240 360 480 600 720 840 960 1080 1200 1320 1440 1560
Q (cfs)
0.00 0.00
4.00 4.00
8.00 8.00
12.00 12.00
16.00 16.00
20.00 20.00
24.00 24.00
Q (cfs)
Time (min)
SW to Pond
Hyd. No. 8 -- 50 Year
Hyd No. 8 Hyd No. 5 Total storage used = 21,325 cuft
Hydrograph Report
Hydraflow Hydrographs Extension for AutoCAD® Civil 3D® 2016 by Autodesk, Inc. v11 Monday, 10 / 8 / 2018
Hyd. No. 9
Southwest Post Combined
Hydrograph type = Combine Peak discharge = 11.67 cfs
Storm frequency = 50 yrs Time to peak = 720 min
Time interval = 2 min Hyd. volume = 45,310 cuft
Inflow hyds. = 6, 8 Contrib. drain. area = 0.420 ac
47
0 120 240 360 480 600 720 840 960 1080 1200 1320 1440 1560
Q (cfs)
0.00 0.00
2.00 2.00
4.00 4.00
6.00 6.00
8.00 8.00
10.00 10.00
12.00 12.00
Q (cfs)
Time (min)
Southwest Post Combined
Hyd. No. 9 -- 50 Year
Hyd No. 9 Hyd No. 6 Hyd No. 8
Hydrograph Report
Hydraflow Hydrographs Extension for AutoCAD® Civil 3D® 2016 by Autodesk, Inc. v11 Monday, 10 / 8 / 2018
Hyd. No. 1
West(SB1)-Pre
Hydrograph type = SCS Runoff Peak discharge = 19.35 cfs
Storm frequency = 100 yrs Time to peak = 716 min
Time interval = 2 min Hyd. volume = 41,452 cuft
Drainage area = 2.020 ac Curve number = 85*
Basin Slope = 0.0 % Hydraulic length = 0 ft
Tc method = User Time of conc. (Tc) = 5.00 min
Total precip. = 7.81 in Distribution = Type II
Storm duration = 24 hrs Shape factor = 484
* Composite (Area/CN) = [(1.080 x 98) + (0.940 x 69)] / 2.020
48
0 120 240 360 480 600 720 840 960 1080 1200
Q (cfs)
0.00 0.00
3.00 3.00
6.00 6.00
9.00 9.00
12.00 12.00
15.00 15.00
18.00 18.00
21.00 21.00
Q (cfs)
Time (min)
West(SB1)-Pre
Hyd. No. 1 -- 100 Year
Hyd No. 1
Hydrograph Report
Hydraflow Hydrographs Extension for AutoCAD® Civil 3D® 2016 by Autodesk, Inc. v11 Monday, 10 / 8 / 2018
Hyd. No. 2
Southwest(SB2)-Pre
Hydrograph type = SCS Runoff Peak discharge = 17.66 cfs
Storm frequency = 100 yrs Time to peak = 716 min
Time interval = 2 min Hyd. volume = 36,018 cuft
Drainage area = 2.280 ac Curve number = 73*
Basin Slope = 0.0 % Hydraulic length = 0 ft
Tc method = User Time of conc. (Tc) = 5.00 min
Total precip. = 7.81 in Distribution = Type II
Storm duration = 24 hrs Shape factor = 484
* Composite (Area/CN) = [(0.300 x 98) + (1.980 x 69)] / 2.280
49
0 120 240 360 480 600 720 840 960 1080 1200 1320 1440
Q (cfs)
0.00 0.00
3.00 3.00
6.00 6.00
9.00 9.00
12.00 12.00
15.00 15.00
18.00 18.00
Q (cfs)
Time (min)
Southwest(SB2)-Pre
Hyd. No. 2 -- 100 Year
Hyd No. 2
Hydrograph Report
Hydraflow Hydrographs Extension for AutoCAD® Civil 3D® 2016 by Autodesk, Inc. v11 Monday, 10 / 8 / 2018
Hyd. No. 3
South(SB3)-Pre
Hydrograph type = SCS Runoff Peak discharge = 6.436 cfs
Storm frequency = 100 yrs Time to peak = 716 min
Time interval = 2 min Hyd. volume = 13,233 cuft
Drainage area = 0.780 ac Curve number = 76*
Basin Slope = 0.0 % Hydraulic length = 0 ft
Tc method = User Time of conc. (Tc) = 5.00 min
Total precip. = 7.81 in Distribution = Type II
Storm duration = 24 hrs Shape factor = 484
* Composite (Area/CN) = [(0.190 x 98) + (0.590 x 69)] / 0.780
50
0 120 240 360 480 600 720 840 960 1080 1200 1320
Q (cfs)
0.00 0.00
1.00 1.00
2.00 2.00
3.00 3.00
4.00 4.00
5.00 5.00
6.00 6.00
7.00 7.00
Q (cfs)
Time (min)
South(SB3)-Pre
Hyd. No. 3 -- 100 Year
Hyd No. 3
Hydrograph Report
Hydraflow Hydrographs Extension for AutoCAD® Civil 3D® 2016 by Autodesk, Inc. v11 Monday, 10 / 8 / 2018
Hyd. No. 4
West(SB1)-Post
Hydrograph type = SCS Runoff Peak discharge = 17.52 cfs
Storm frequency = 100 yrs Time to peak = 716 min
Time interval = 2 min Hyd. volume = 36,917 cuft
Drainage area = 1.910 ac Curve number = 82*
Basin Slope = 0.0 % Hydraulic length = 0 ft
Tc method = User Time of conc. (Tc) = 5.00 min
Total precip. = 7.81 in Distribution = Type II
Storm duration = 24 hrs Shape factor = 484
* Composite (Area/CN) = [(0.850 x 98) + (1.060 x 69)] / 1.910
51
0 120 240 360 480 600 720 840 960 1080 1200
Q (cfs)
0.00 0.00
3.00 3.00
6.00 6.00
9.00 9.00
12.00 12.00
15.00 15.00
18.00 18.00
Q (cfs)
Time (min)
West(SB1)-Post
Hyd. No. 4 -- 100 Year
Hyd No. 4
Hydrograph Report
Hydraflow Hydrographs Extension for AutoCAD® Civil 3D® 2016 by Autodesk, Inc. v11 Monday, 10 / 8 / 2018
Hyd. No. 5
Southwest(SB2)-Pond
Hydrograph type = SCS Runoff Peak discharge = 26.24 cfs
Storm frequency = 100 yrs Time to peak = 716 min
Time interval = 2 min Hyd. volume = 56,228 cuft
Drainage area = 2.740 ac Curve number = 85*
Basin Slope = 0.0 % Hydraulic length = 0 ft
Tc method = User Time of conc. (Tc) = 5.00 min
Total precip. = 7.81 in Distribution = Type II
Storm duration = 24 hrs Shape factor = 484
* Composite (Area/CN) = [(1.530 x 98) + (1.210 x 69)] / 2.740
52
0 120 240 360 480 600 720 840 960 1080 1200
Q (cfs)
0.00 0.00
4.00 4.00
8.00 8.00
12.00 12.00
16.00 16.00
20.00 20.00
24.00 24.00
28.00 28.00
Q (cfs)
Time (min)
Southwest(SB2)-Pond
Hyd. No. 5 -- 100 Year
Hyd No. 5
Hydrograph Report
Hydraflow Hydrographs Extension for AutoCAD® Civil 3D® 2016 by Autodesk, Inc. v11 Monday, 10 / 8 / 2018
Hyd. No. 6
Southwest(SB2)-Bypass Post
Hydrograph type = SCS Runoff Peak discharge = 2.957 cfs
Storm frequency = 100 yrs Time to peak = 716 min
Time interval = 2 min Hyd. volume = 5,987 cuft
Drainage area = 0.420 ac Curve number = 69*
Basin Slope = 0.0 % Hydraulic length = 0 ft
Tc method = User Time of conc. (Tc) = 5.00 min
Total precip. = 7.81 in Distribution = Type II
Storm duration = 24 hrs Shape factor = 484
* Composite (Area/CN) = + (0.420 x 69)] / 0.420
53
0 120 240 360 480 600 720 840 960 1080 1200 1320 1440
Q (cfs)
0.00 0.00
1.00 1.00
2.00 2.00
3.00 3.00
Q (cfs)
Time (min)
Southwest(SB2)-Bypass Post
Hyd. No. 6 -- 100 Year
Hyd No. 6
Hydrograph Report
Hydraflow Hydrographs Extension for AutoCAD® Civil 3D® 2016 by Autodesk, Inc. v11 Monday, 10 / 8 / 2018
Hyd. No. 7
South(SB3)-Post
Hydrograph type = SCS Runoff Peak discharge = 0.141 cfs
Storm frequency = 100 yrs Time to peak = 716 min
Time interval = 2 min Hyd. volume = 285 cuft
Drainage area = 0.020 ac Curve number = 69*
Basin Slope = 0.0 % Hydraulic length = 0 ft
Tc method = User Time of conc. (Tc) = 5.00 min
Total precip. = 7.81 in Distribution = Type II
Storm duration = 24 hrs Shape factor = 484
* Composite (Area/CN) = + (0.040 x 69)] / 0.020
54
0 120 240 360 480 600 720 840 960 1080 1200 1320 1440
Q (cfs)
0.00 0.00
0.05 0.05
0.10 0.10
0.15 0.15
0.20 0.20
0.25 0.25
0.30 0.30
0.35 0.35
0.40 0.40
0.45 0.45
0.50 0.50
Q (cfs)
Time (min)
South(SB3)-Post
Hyd. No. 7 -- 100 Year
Hyd No. 7
Hydrograph Report
Hydraflow Hydrographs Extension for AutoCAD® Civil 3D® 2016 by Autodesk, Inc. v11 Monday, 10 / 8 / 2018
Hyd. No. 8
SW to Pond
Hydrograph type = Reservoir Peak discharge = 11.41 cfs
Storm frequency = 100 yrs Time to peak = 722 min
Time interval = 2 min Hyd. volume = 47,941 cuft
Inflow hyd. No. = 5 - Southwest(SB2)-Pond Max. Elevation = 277.70 ft
Reservoir name = Wet Pond Max. Storage = 23,900 cuft
Storage Indication method used.
55
0 120 240 360 480 600 720 840 960 1080 1200 1320 1440 1560
Q (cfs)
0.00 0.00
4.00 4.00
8.00 8.00
12.00 12.00
16.00 16.00
20.00 20.00
24.00 24.00
28.00 28.00
Q (cfs)
Time (min)
SW to Pond
Hyd. No. 8 -- 100 Year
Hyd No. 8 Hyd No. 5 Total storage used = 23,900 cuft
Hydrograph Report
Hydraflow Hydrographs Extension for AutoCAD® Civil 3D® 2016 by Autodesk, Inc. v11 Monday, 10 / 8 / 2018
Hyd. No. 9
Southwest Post Combined
Hydrograph type = Combine Peak discharge = 13.46 cfs
Storm frequency = 100 yrs Time to peak = 720 min
Time interval = 2 min Hyd. volume = 53,928 cuft
Inflow hyds. = 6, 8 Contrib. drain. area = 0.420 ac
56
0 120 240 360 480 600 720 840 960 1080 1200 1320 1440 1560
Q (cfs)
0.00 0.00
2.00 2.00
4.00 4.00
6.00 6.00
8.00 8.00
10.00 10.00
12.00 12.00
14.00 14.00
Q (cfs)
Time (min)
Southwest Post Combined
Hyd. No. 9 -- 100 Year
Hyd No. 9 Hyd No. 6 Hyd No. 8
Hydraflow Rainfall Report
57
Hydraflow Hydrographs Extension for AutoCAD® Civil 3D® 2016 by Autodesk, Inc. v11 Monday, 10 / 8 / 2018
Return Intensity-Duration-Frequency Equation Coefficients (FHA)
Period
(Yrs) B D E (N/A)
1 0.0000 0.0000 0.0000 --------
2 69.8703 13.1000 0.8658 --------
3 0.0000 0.0000 0.0000 --------
5 79.2597 14.6000 0.8369 --------
10 88.2351 15.5000 0.8279 --------
25 102.6072 16.5000 0.8217 --------
50 114.8193 17.2000 0.8199 --------
100 127.1596 17.8000 0.8186 --------
File name: SampleFHA.idf
Intensity = B / (Tc + D)^E
Return Intensity Values (in/hr)
Period
(Yrs) 5 min 10 15 20 25 30 35 40 45 50 55 60
1 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00
2 5.69 4.61 3.89 3.38 2.99 2.69 2.44 2.24 2.07 1.93 1.81 1.70
3 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00
5 6.57 5.43 4.65 4.08 3.65 3.30 3.02 2.79 2.59 2.42 2.27 2.15
10 7.24 6.04 5.21 4.59 4.12 3.74 3.43 3.17 2.95 2.77 2.60 2.46
25 8.25 6.95 6.03 5.34 4.80 4.38 4.02 3.73 3.48 3.26 3.07 2.91
50 9.04 7.65 6.66 5.92 5.34 4.87 4.49 4.16 3.88 3.65 3.44 3.25
100 9.83 8.36 7.30 6.50 5.87 5.36 4.94 4.59 4.29 4.03 3.80 3.60
Tc = time in minutes. Values may exceed 60.
Rainfall Precipitation Table (in)
Precip. file name: P:\Projects\2017\17050 - Franklin Medical Center\Engineering\Louisburg Prec Depths.pcp
Storm
Distribution 1-yr 2-yr 3-yr 5-yr 10-yr 25-yr 50-yr 100-yr
SCS 24-hour 2.90 3.50 0.00 4.41 5.13 6.14 6.96 7.81
SCS 6-Hr 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00
Huff-1st 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00
Huff-2nd 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00
Huff-3rd 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00
Huff-4th 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00
Huff-Indy 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00
Custom 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00