20131200 Ver 2_Area 3B - stormwater calcs_20140909

,O, J , j' s. S 1,

Rational Method
Designed By: JCW Date: 8/18/2014
Checked By: DWO Date:
Company: ODOM ENGINEERING
Project Name: Tryon Equestrian AREA 1
Proiect No.: 13017
The rational formula is:
Q = CIA
tvhem:
C = peak rate of runoff in cubic feet per second (ch)
C = runoff coeff ctent, an empirical coef7aent representing the
relationship betueemcainfall rate and nmoff rate
I = average intensity ofminfall in inches/hou,, for a stams duration equal
to the time of concentration, To
A = drainage area in acres
The general procetime for determining peak discharge using the rational
fomnda is presented beloty and illustrated in Sample problem 8.03a.
Step 1. Determine the drainage area in acres.
Drainage Area 1.03
Step I Determine the maeff coefficient, C, for the type of soih'cover in the
drainage am (Table 8.03b).
If the laud use and soil rata is homogenous ova the drainage area, a C
value caa be determined dhadly from Table 8.036. If there are multiple sod
cots conditions, a weighted average must be calculated or the area may be
subdivided.
Subarea A (acres) 1.03
Subarea A Runoff Coefficient 0.9 Runoff Coefficient
Subarea B (acres)
Subarea B Runoff Coefficient
Subarea C (acres)
Subarea C Runoff Coefficient
Subarea D (acres)
Subarea D Runoff Coefficient
Weighted Runoff Coefficient 0.9
3
4.
r Rainfall Intensity, i (Inmf) 0
at Rainfall Intensity, 1(inmr) 8.53
Step 5. Determine peak discharge, Q (cubic feet per smomil, by multiplying
the pmiomly determined factors using the mtional formula (Sample Prmblem
0 =CIA
Qa Flow (cfs) 0
Qta Flow lots) 7.9

Rational Method
(Reference Data I
811
DWO
ODOM ENGINEERING
Tryon Equestrian AREA 1
The railroad formua is:
Q = CIA
where:
Q = peaknte of nmoff in rabic feet persecomd (cfs)
C = tuuoffcce& dent, an empirical coefficient representing the
relationship between rainfall rate and nmuff rate
1 = average urmsity of mmM is inches/hour, fm a storm duration equal
to the time of concentration, Te
A = dravuge area in arses
The general procedure for determining peals discharge using the rational
formla is presented below and Mustrated in Sample problem 8.03x.
Snap 1. Determine the drainage area in acres-
. otal Drainage Area 0.79
Step 2. Determine the nmoff coefficient, C, for the type of soillcover in the
drainage area (fable 8.03b).
If the land use and sod cover is homogenous micr the drainage area, a C
value nn be determined dmecdy finny ('able 8.036. If there are multiple soil
cover conditions. a weighted avenge must be calculated, or the area may be
subdivided.
Subarea A (acres) 0.79
Subarea A Runoff Coefficient 0.9 Runoff Coeffdent
Subarea B (acres)
Subarea B Runoff Coefficient
Subarea C (acres)
Subarea C Runoff Coefficient
Subarea D (acres)
Subarea D Runoff Coefficient
Weighted Runoff Coefficient 0.9
ti
Step 4.
2 -year Rainfall Intensity, i (inlhr) 0
25 -year Rainfall Intensity, i (in/hr) 8.53
Step S. Determine peal- discharge, Q (cubic feet per semud), by multiplying
the previously determined factors using the rational formula (Sample problem
S.03a):
Q =CIA
Qz Flow (cfs) 0
Qto Flow (cfs) 6.1

ESTIMATING RUNOFF
Rational Method
User Input Data
Calculated Value
Reference Data
Designed By: JCW Date: 8/18/2014
Checked By: DWO Date:
Company: ODOM ENGINEERING
Project Name: Tryon Equestrian AREA 1
Project No.: 13017
Site Location (Cityfrown) tryon
CATCH BASIN # 60.
She rational forrmda is:
Q =CIA
where:
Q = peak rate of mmoffin cubic feet per second (cfs)
C = nmoffcoefficient, an empirical coefficient representing the
relationship bemeen minfall rate and ruooffrate
I = average intensity ofmiafalt in iucheslhom, for a storm duration equal
in the time of concentration. To
A = drainage area in acres
The general procedure for determining peak discharge using the rational
formula is presented below and illustrated in Sample problem 8.03x.
Step 1. Determine the drainage area in acres.
Total Drainage Area 0.7
Step 2. Determine the mnaff coefficient, C, for the type of soillcoter in the
drainage area (Table 8.03b).
If the laud use and sod cater is homogenous over the drainage area, a C
value can be deter ,tan d directly fiom Sable 8.03b. If there me multiple sod
ccntt conditions, a weighted average must be calculated. or the area may be
subdivided.
Subarea A (acres) 0.7
Subarea A Runoff Coefficient 0.25 Runoff coefficient
Subarea B (acres)
Subarea B Runoff Coefficient
Subarea C (acres)
Subarea C Runoff Coefficient
Subarea D (acres)
Subarea D Runoff Coefficient
Weighted Runoff Coefficient 0.25
Step 3.
Go to Intensity Worksheet
Step 4.
2 -year Rainfall Intensity, i (in/hr) - 0
25 -year Rainfall Intensity, i (inlhr) 8.53
Step S. Determine peak discharge, Q (cubic feet per second), by multiplying
the previously determined factors using the rational formula (Sample problem
&03a);
Q =CIA
Qr Flow (cfs) 0
Qua Flow (cfs) 1.5

ESTIMATING RUNOFF
Rational Method
User Input Data
Calculated Value
Reference Data
Designed By: JCW Date: Sf,1812014
Checked By: DWO Date:
Company: ODOM ENGINEERING
Project Name: Tryon Equestrian AREA 1
Project No.: 13017
Site Location (City/Town) Iryon
CATCH BASIN # 59
Ibe national fmmmla is:
Q = CIA
uttere:
Q = peak rate ofrmaffim cubic fret per second (c$)
C = runoff coefficient, an empirical. coefficient representing the
relationship berveen rainfall rate and nmoff rate
I = average intensity of rainfall in incluvhouc for a stem duration equal
to the time ofcmmmtration, Tc
A= drainage area in arm
The general procedure for determining peak discharge using the rational
formula is presented below and illustrated in Sample Problem S.03a
Step 1. Determine the drayage area in acres.
Total Drainage Area 024
Step 2. Detemtim the nmoffcoefficiew. C, for the type of soillcover in the
drainage area (fable 8.03b).
If die Land use and .sail cover u homogenous over the drainage area, a C
value can be determined directly fima Table 8.036. If these are multiple sod
cover conditions, a weighted avenge must be calculated, or the atea may be
subditided.
Subarea A (acres) 0.94
Subarea A Runoff Coefficient 025 Runoff Coefficient
Subarea B (acres)
Subarea B Runoff Coefficient
Subarea C (acres)
Subarea C Runoff Coefficient
Subarea D (acres)
Subarea D Runoff Coefficient
Weighted Runoff Coefficient 0.25
Step 3.
Go to Intensity Worksheet
Step 4.
2 -year Rainfall Intensity, 1(inlhr) 0
25 -year Rainfall Intensity, i (in/hr) 8!53
Step S. Determine peal- discharge, Q (cubic feet per second), by multiplying
the previously determined factors using the rational formula (Sample problem
8.033):
Q =CIA
Qa Flow (cfs) 0
Qta Flow (cfs) 2.0

ESTIMATING RUNOFF
Rational Method
User Input Data
Calculated Value
Reference Data
Designed By: dCW Date: 8/18/2014
Checked By: DWO Date:
Company: ODOM ENGINEERING
Project Name: Tryon Equestrian AREA I
Project No.: 13017
Site Location (City/Town) tryon
CATCH BASIN # 58
The rational formula is:
Q =CIA
where:
Q = peak rate ofmuoffin cubic feet per second(cf.)
C = naoffcoefficient, an empirical coeffiaent representing the
relationship betweenramrall rate and runoff rate
I = amerage intensity of rainhIl in inches/hour. for a storm duration equal
to the time of concentratiom To
A = drainage area in arses
The general procedure for determining peak discharge using the rational
formula is presented below and illustrated in Sample problem S.03a.
Step 1. Determine the drainage area in acres.
Total Drainage Area 1.54
Step 2. Determine the runoff coefficient. C. for the type of soil/cover in the
drainage area (Table S.03b).
If the laud use and sail coyer is homogeaous over the drainage atea, a C
value can be determined directly fiwm Table 8.03b. If there are multiple sod
cover conditions• a uxighted average most be calculated or the area may be
subdisgded.
Subarea A (acres) 1.54
Subarea A Runoff Coefficient 0.25 Runoff Coefficient
Subarea B (acres)
Subarea B Runoff Coefficient
Subarea C (acres)
Subarea C Runoff Coefficient
Subarea D (acres)
Subarea D Runoff Coefficient
Weighted Runoff Coefficient 0.25
Step 3.
Go to Intensity Worksheet
Step 4.
2 -year Rainfall Intensity, i (inlhr) 0
25 -year Rainfall Intensity, i (inlhr) 8.53
Step 5. Determine peak d' cha e , O ( cubic feet per second), by multiplying
the previauslydetermined factors using the rational fomula (Sample problem
8.033):
O =CIA
Qa Flow (cfs) 0
Qtn Flow (cfs) 3.3

ESTIMATING RUNOFF
Rational Method
User Input Data
Calculated Value
Reference Data
Designed By: JCW Date: 811 812 01 4
Checked By: DWO Date:
Company: ODOM ENGINEERING
Project Name: Tryon Equestrian AREA 1
Project No.: 13017
Site Location(CitylTown) tryon
CATCH BASIN # 55
The rational formula is:
Q = CIA
When:
Q = peak rate of runoff in cubic feet per second (ds)
C = runoff coefficient. an empirical coefficient representing the
relationship behveea rainfall rate and rmmffrate
I = average intensity ofrain£dl in iurhes/lsom. for a stow duration equal
to the time of concentration, To
A= drainage area in acres
The general procedure for determining peak discharge miag the muonal
formula is presented below and illustrated in Sample Problem 8.03a.
Step 1. Determine the drainage area in acres.
Total Drainage Area 0.45
Step i. Determine the runoff coefficient. C, for the type of soillomer in the
drainage area (Table 8.03b).
If the laud use and sod cover is homogenous o%a the drainage area, a C
%aloe can be determined directly firma Table 8.03b. If there are multiple sal
cover coalitions, a weighted a%aage most be calculated. or the area may be
subdivided.
Subarea A (acres) 0.45
Subarea A Runoff Coefficient 0.9 Runoff Coefficient
Subarea B (acres)
Subarea B Runoff Coefficient
Subarea C (acres)
Subarea C Runoff Coefficient
Subarea D (acres)
Subarea D Runoff Coefficient
Weighted Runoff Coefficient 0.9
Step 3.
Go to Intensity Worksheet
Step 4.
2 -year Rainfall Intensity, i (in/hr) 0
25 -year Rainfall Intensity, i (inlhr) 8.53
Step 5. Determine peak discharge, 0 (cubic feet per second), by multiplying
the prevtouslydetermined factors using the rational li mula (Sample Problem
8.03x);
0 =CIA
Qa Flow (cfs) 0
Qra Flow (cfs) 3.5

Rational Method
User Input Data
Calculated Value
Reference Data
Designed By: JCW Date: :8/1812014
Checked By: DWO Date:
Company: ODOM ENGINEERING
Project Name: Tryon Equestrian AREA 1
Project No.: 13017
Sttte Location (Cityfrown) tryon
CATCH BASIN # 54
The rational formula is:
Q = CIA
where:
Q = peak rate of rumuff in cubic feet per second (cfs)
C = nmoffcoefficient, anempirical coefficient representing the
rdaiooship ber een ram6Urate and rmroffrate
I = average intensity ofrainfi l in inchmhour. for a stone duration equal
to the time of concenaation. Tc
A = drainage area in acres
The general procedure for determiung peak duclharge using the rational
formula is presented below and illustrated in Sample problem 8.03x.
Step 1. Determine the drainage area in acres.
Total Drainage Area 0.53
Step 2. Determine the wr off coefficient. C, for the type of soil lcover in the
drainage area (Table 8.03b).
If the land use and sod cover is homogenous over the drainage area, a C
value can be determined directly 6-am Table 8.03b. If them are multiple soil
cover conditions, a weighted average nuut be calculated or the area may be
subdivided.
Subarea A (acres) 0.53
Subarea A Runoff Coefficient 0.9 Runoff Coefficient
Subarea B (acres)
Subarea B Runoff Coefficient
Subarea C (acres)
Subarea C Runoff Coefficient
Subarea D (acres)
Subarea D Runoff Coefficient
Weighted Runoff Coefficient 0.9
Step 3.
Go to Intensity Worksheet
Step 4.
2 -year Rainfall Intensity, i (in)hr) 0
25 -year Rainfall Intensity, i (in/hr) 8.53
Step 5. Determine peak discharge, Q (cubic feet per second), by multiplying
thepreviously determined factors using the rational formula (Sample emblem
8.03a):
Q =CIA
Qa Flow(cfs) 0
Qta Flow (cfs) 4.1

C�.
Rational Method
Data
JCW
DWO
ODOM ENGINEERING
Tryon Equestrian AREA 1
tryon
65
The rational formula is:
Q = CIA
where:
Q = peak rate of runoff in cubic feet per second (cfs)
C = nwoff coe[icient, an empirical coefficient representing the
relationship between rainfall rate and nmeff raw
I = average intensity ofrairE'I in inches�how, for a storm duration equal
m the time of concentration. Tc
A = drainage area in acres
The general procedure for determining peak darharge using the rational
formula is presented below and illustrated in Sample Problem 8.03x_
Step 1. Determine the drainage area in acres.
Total Drainage Area 0.31
Step 2. Determine the nmoff caefficient, C, far the type of soil/cover in the
drainage area (Table 8.03b).
If the laud use and soil cover is homogenous over the drainage area, a C
value can be determined directly from Table 8.03b. If there are multiple soil
cover condition. a weighted average must be calculated or the area may be
subdivided.
Subarea A (acres) 0.31
Subarea A Runoff Coefficient 0.25 Runoff Coefficient
Subarea B (acres)
Subarea B Runoff Coefficient
Subarea C (acres)
Subarea C Runoff Coefficient
Subarea D (acres)
Subarea D Runoff Coefficient
Weiohled Runoff Coefficient 0.25
3.
4.
it Rainfall Intensity, 1(fnthr) 0
!at Rainfall Intensity, i (inlhr) 8.53
Step S. Determine peat: discharge: Q (cubic feet per second), by multiplying
the pmiosulydetemoned faam using the rational formula (Sample problem
8.03a);
Q =CIA
Qr Flow (Cfs) 0
Qtn Flow (cfs) 0.7

C
ESTIMATING RUNOFF
Rational Method
User Input Data
Calculated Value
Reference Data
Designed By: JCW Date: 8/18/2014
Checked By: DWO Date:
Company: ODOM ENGINEERING
Project Name: Tryon Equestrian AREA 1
Project No.: 13017
Site Location (City/Town) tryon
CATCH BASIN # 64
The mtiorml formula a:
Q = CIA
where-
0 = peak rate of runoff in cubic feer per second (cfs)
C = runoffcoeBdeat, an empirical coefficient representing the
relationship between rainfall rate and runoff rate
I = a%e ge intensity of rainfall in indres'hom.. for a storm duration equal
to the time of concearation. To
A = drainage area in acres
The general procedure for determining peak discharge using the notional
forffida is presented below and illustrated in Sample Problem 8.03u
Step 1. Determine the drainage area in acres.
Total Drainage Area 0.41
Step 3. Determine the runoff coefficient, C, for the type of soilicover in the
drainage area (Table 8.03b).
If the land use and sad cmro is homogenous over the drainage area. a C
value can be determined directly from Table 8.036. If there are multiple sod
cover conditions, a weighted average must be calculated, or the area may be
suldticnded.
Subarea A (acres) 0.41
Subarea A Runoff Coefficient 0.25 Runoff Coetrdern
Subarea B (acres)
Subarea B Runoff Coefficient
Subarea C (acres)
Subarea C Runoff Coefficient
Subarea D (acres)
Subarea D Runoff Coefficient
Weighted Runoff Coefficient 0.25
Step 3.
Go to Intensity Worksheet
Step 4.
2 -year Rainfall Intensity, i (In/hr) 0
25 -year Rainfall Intensity, i (inlhr) 8.53
Step S. Determine peak discharge. Q ( cubic feet per second), by multiplying
thepm7omly determined factors using the rational formula (Sample problem
8.03x);
Q =CIA
Qa Flow (cfs) 0
Qta Flow (cfs) 0.9

ESTIFAATING RUNOFF
Rational Method
User Input Data
Calculated Value
Reference Data
Designed By: JCW Date: 8/1812014
Checked By: DWO Date:
Company: ODOM ENGINEERING
Project Name: Tryon Equestrian AREA 1
Project No.: 13017
Site Location (City/Town) tryon
CATCH BASIN # 63
The rational formula is:
Q = CIA
AdleIG
Q = peak ate of nu off to cubic feet per second (cfs)
C = wooffcoeffuiem, an empirical coefficiem representing the
relationship benceen rainfall rate and nnmff ram
1 = average intensity of mitda0 in urches hour, for a storm duration equal
to dm time of concerrcation. Tc
A= dainage area in acres
The general procedure for determining peak discharge mum the rational
formula is presented below and illustrated in SuVle problem 8.03a.
Step 1. Determine the drainage area in acres.
Total Drainage Area 0.18
Step 2. Determine the nmoff coefficient, C, for the type of soilicover in the
drainage area (fable 8.036).
If the land use and soil covet is homogenous over the drainage area, a C
value eau be determined directly from Table 8.03b. If there are multiple cad
cma conditions, a weighted average muse be calculated, or the area may be
subdivided.
Subarea A (acres) 0.18
Subarea A Runoff Coefficient 0.25 Runoff Coefficient
Subarea B (acres)
Subarea B Runoff Coefficient
Subarea C (acres)
Subarea C Runoff Coefficient
Subarea D (acres)
Subarea D Runoff Coefficient
Weighted Runoff Coefficient 0.25
Step 3.
Go to Intensity Worksheet
Step 4.
2 -year Rainfall Intensity, t (inthr) 0
25 -year Rainfall Intensity, i (in/hr) 8.53
Step S. Determine peal- discharge, Q (cubic feet per secmtd), by mulmplymg
the previouslydetemuned factors usiag the rational formula (Sample Problem
8.03a);
Q =CIA
Qa Flow (cfs) 0
Qto Flow (cfs) 0.4

Rational Method
User Input Data
Calculated Value
Reference Data
Designed By: JCW Date: 8/18/2014
Checked By: DWO Date:
Company: ODOM ENGINEERING
Project Name: Tryon Equestrian AREA 1
Project No.: 13017
Site Location (Cityrrown) Tryon
CATCH BASIN # 52
The rational formula is:
Q =CIA
where:
Q = peak rate of runoff in cubic feet per second (cfs)
C = nmoff coe&ciemt an empirical coefficient representing the
relationship between rainfall rate and runoff rate
I = average intensity of tainfall in inchm1hour, fm a storm duration equal
to the time of concentration. Tr
A = drainage area in acres
The general procedure for determining peak discharge using the rational
forr®la is presented below and illustrated in Sample problem 8.03x.
Step 1. Determine the drainage area at acres.
Total Drainage Area 1.35
Step 2. Determine the nmoffcoefficient, C, for the type of soil cover in the
drainage area (Table 8.03b).
If the Land use and soil covxr u homogenous over the drainage area. a C
value ran be determined directly from Table 8.03b. If there are multiple soil
cover conditions, a weighted avenge mast be calculated or the area may be
subdivided.
Subarea A (acres) 1.35
Subarea A Runoff Coefficient 0.25 Runoff Coeffldem
Subarea B (acres)
Subarea B Runoff Coefficient
Subarea C (acres)
Subarea C Runoff Coefficient
Subarea D (acres)
Subarea D Runoff Coefficient
Weighted Runoff Coefficient 0.25
Step 3.
go to Intensity Worksheet
Step 4.
2 -year Rainfall Intensity, i (inlhr) 0
25 -year Rainfall Intensity, i (inthr) 8,53
Step S. Determine peak discharge. Q (cubic feet per second), by multiplying
the previously determined factors using the rational formula (Sample problem
S.03a);
Q =CIA
Qa Flow (cfs) 0
Quo Flow (cfs) 2.9

Rational Method
User Input Data
Calculated Value
Reference Data
Designed By: JCW Date: 8/1812014
Checked By: DWO Date:
Company: ODOM ENGINEERING
Project Name: Tryon Equestrian AREA 1
Project No.: 13017
Site Location (City/Town) tryon
CATCH BASIN # 51
The rational formula iv
Q = CIA
where:
Q = peakrate ofmooff in eabic fees per second (efs)
C = runoff coet8aent an empirical coefficent repmeving the
relationship bemeen miufall rate and turi raw
I = average int ensity oftainfall in inchesmLouc for a stone duration equal
to the time of concentration, To
A = drainage area in acres
The general procedure for determining peak discharge using the rational
formula u presented below and illustrated in Sample problem 8.03x.
Step 1. Determine the drainage area in acres.
Total Drainage Area 1.34
Step 2. Determine the narmff coefficient, C, for the type of soillcover in the
dminage area (Table 8.03b).
If the Land me and soil cover is homogenous over the drainage area, a C
value cm be determined directly from Table 8.036. If there are multiple soil
cover conditions. a weighted average most be calculated, or the area may be
subdivided.
Subarea A (acres) 1.34
Subarea A Runoff Coefficient 0.25 Runoff cosi
Subarea B (acres)
Subarea B Runoff Coefficient
Subarea C (acres)
Subarea C Runoff Coefficient
Subarea D (acres)
Subarea D Runoff Coefficient
Weighted Runoff Coefficient 0.25
Step 3.
Go to Intensity Worksheet
Step 4.
2 -year Rainfall Intensity, i (in#tr) 0
25 -year Rainfall Intensity, i (irt/hr) 8.53
Step S. Determine peak discharge, Q (cubic feet per second), by multiplying
du previouslydetemrined factors using the mtioml formula (Sample probler
8.033):
Q =CIA
Qa Flow (cfs) 0
Qto Flow (cfs) 2.9

Rational Method
Value
Designed fay:
JCW Date: 8/18/2014
Checked By:
DWO Date:
Company:
ODOM ENGINEERING
Project Name:
Tryon Equestrian AREA 1
The rational formula is:
Q = CIA
where:
0 = peak rate of runoff in cubic feet per second (cfs)
C = runoff coeffrciem, an empirical coefficient representing the
relationship between rsmfall we and runoff tare
I = average intensity of rainfall in inrltestfiour. for a stone duration equal
to the time of concentration, To
A= drainage area in acres
The general procedure for determining peak discharge using the rational
formula is presented below and illustrated in Sample problem 8.03a.
Step 1. Determine the drainage area in acres.
Drainage Area 0.42
Step 3. Determine the nuroff coefficient, C, for the type of soiUcover in the
drainage area (Table 8.03b).
If the land use and soil cots ts homogenous user the drainage area, a C
value can be determined directly from Table 8A3b. If there are multiple soil
co%w comlitions, a weighted avenge must be calculated or the area may be
subdivided.
Subarea A (acres) 0.42
Subarea A Runoff Coefficient 0.9 Runoff Coefflclent
Subarea B (acres)
Subarea B Runoff Coefficient
Subarea C (acres)
Subarea C Runoff Coefficient
Subarea D (acres)
Subarea D Runoff Coefficient
Weighted Runoff Coefficient 0.9
4.
r Rainfall Intensity, i (inthr) 0
at Rainfall Intensity, i (in/hr) 8.53
5. Determine peal- discharge, Q (cubic feet per second), by multiplying
an iously determined faciars using the rational formula (Sample problem
0 =CIA
Flow (cfs)
, Flow Ids)
0
3.2

C
ESTIMATING RUNOFF
Rational Method
User Input Data
Calculated Value
Reference Data
Designed By: JCW Date: 8/18/2014
Checked By: DWO Date:
Company: ODOM ENGINEERING _
Project Name:. Tryon Equestrian AREA 1
Project No.: 13017
Site Location (Cityrrown) tryon
CATCH BASIN # 67
The rational formula is:
Q = CIA
where:
Q = peak rate of runoff in cubic feet per second (cfs)
C = rmoff coefficient an empuial coeHiaeut representing the
relationship between ramR11 rate and nmoffrate
I = aaenge intensity ofrainfall in inc& —Aom, for a storm duration equal
to the time of concentration Tc
A= drainage am in acres
The general procedure for detenuoung peak discharge using the national
faamla n presented below and illustrated in Sample problem 8.03x.
Shp 1. Determine the drainage area in acres.
Total Drainage Area 0.72
Step 2. Detn®ine the nmoff coefficient C, for the type of soilicover in the
drainage area (Table 8.03b).
rf the land me and sod cover is homogenous over the drainage area a C
lalue cm be determined directly from Table 8.03b. If there are multiple soil
cosec conditions. a weighted avenge must be calculated. or the area may be
subdivided
Subarea A (acres) 0.72
Subarea A Runoff Coefficient 0.25 Rune coecicleM
Subarea B (acres)
Subarea B Runoff Coefficient
Subarea C (acres)
Subarea C Runoff Coefficient
Subarea D (acres)
Subarea D Runoff Coefficient
Weighted Runoff Coefficient 0.25
Step 3.
Go to Intensity Worksheet
Step 4.
2 -year Rainfall Intensity, 1 (in/hr) 0
25 -year Rainfall Intensity, i (in/hr) 8.53
Step 5. Determine peak discharge. Q (cubic feet per second), by multiplying
the previously determined factors using the rational fonnula.(Sample Problem
8.03a);
Q =CIA
Qa Flow (cfs) 0
Qty Flow (cfs) 1.5

Rational Method
User Input Data
Calculated Value
Reference Data
Designed By: : JCW Date: 8/18/2014
Checked By: DWO Date:
Company: ODOM ENGINEERING
Project Name: Tryon Equestrian AREA 1
Project No.: 13017
Site Location (City/Town) Tryon
CATCH BASIN # 57
The rational fora ila is:
Q =CIA
where:
Q = peak rate of runoff in cubic feet per second (cfs)
C = nmoff coef6ciemS an empincal coefficient repmentutg the
relationship between minfaLL rate and rmtoff rate
I = average imensity of rain ll in incheslow. for a storm duration equal
w the time of concentration, Tc
A= drainage area in acres
The general procedure for determirvng peak discharge using the rational
femnila is presented below and illustrated in Sample Problem 8.032.
Step 1. Determine the dainage area in acres.
Total Drainage Area 0.86
Step 2. Determine the nmoff coefficient. C, for the type of soillcover in the
drainage area (Table 8.03b).
If the land use and soil cover is homogenous over the drainage area, a C
aalue can be determined directly rim Table 8.03b. If there are multiple sod
cots conditions, a weighted average must be calculated, or the area may be
subdtided.
Subarea A (acres) 0.86
Subarea A Runoff Coefficient 0.9 Runoff Coefficient
Subarea B (acres)
Subarea B Runoff Coefficient
Subarea C (acres)
Subarea C Runoff Coefficient
Subarea D (acres)
Subarea D Runoff Coefficient
Weighted Runoff Coefficient 0,9
Step 3.
Go to Intensity Worksheet
Step 4.
2 -year Rainfall Intensity, t (in/hr) 0
25 -year Rainfall Intensity, i (inlhr) 8.53
Step 5. Determine peak discharge, Q (cubic feet per second), by multiply*
the previomlydetemvned factors using the rational formula (Sample problem
8.03a);
Q =CIA
Qr Flow (cfs) 0
Qte Flaw (cfs) 6.6

Channel Report
Hydraflow Express Extension for AutoCAD@ Civil 3D@2013 by Aulodesk, Inc.
( CB #62 TO CB #61
Q (cfs)
Circular
Area (sqft)
Diameter (ft)
= 1.75
Invert Elev (ft)
= 879.40
Slope ( %)
= 0.50
N -Value
= 0.012
Calculations
EGL (ft)
Compute by:
Known Q
Known Q (cfs)
= 7.90
Elev (ft)
s82.00
881.50
881.00
880.50
880.00
14(.11469
879.00
( t378.50
0
Section
Friday, Aug 22 2014
Highlighted
Depth (ft)
= 1.03
Q (cfs)
= 7.900
Area (sqft)
= 1.47
Velocity (fUs)
= 5.36
Wetted Perim (ft)
= 3.06
Crit Depth, Yc (ft)
= 1.04
Top Width (ft)
= 1.72
EGL (ft)
= 1.48
1
2
Reach (ft)
Depth (ft)
2.60
2.10
1.60
1.10
0.60
0.10
-0.40
-0.90
4

Channel Report
Hydraflow Express Extension for AutoCAD(9) Civil 3D@2013 by Autodesk, Inc.
CB #61 TO CB #60
Q (cfs)
Circular
Area (sqft)
Diameter (ft)
= 2.00
Invert Elev (ft)
= 878.90
Slope ( %)
= 0.50
N -Value
= 0.012
Calculations
EGL (ft)
Compute by:
Known Q
Known Q (cfs)
= 14.00
Elev (ft)
881.00 -
880.50
:1[0)611]
I -YU M
1
Section
2
Reach (ft)
Friday, Aug 22 2014
Highlighted
Depth (ft)
= 1.37
Q (cfs)
= 14.00
Area (sqft)
= 2.29
Velocity (ft/s)
= 6.10
Wetted Perim (ft)
= 3.90
Crit Depth, Yc (ft)
= 1.35
Top Width (ft)
= 1.86
EGL (ft)
= 1.95
3
Depth (ft)
2.10
1.60
1.10
M
0.10
-0.40
1 - -0.90
4

Channel Report
Hydraflow Express Extension for AutoCAD® Civil 3138 2013 by Autodesk, Inc.
CB #60 TO CB #59
Circular
Diameter (ft)
= 2.00
Invert Elev (ft)
= 878.10
Slope ( %)
= 0.50
N -Value
= 0.012
Calculations
Compute by:
Known Q
Known Q (cfs)
= 15.50
Elev (ft)
881.00
C_
880.50
879.50
878.50
:MM4l1
877.50
0
Section
Highlighted
Depth (ft)
Q (Cfs)
Area (sqft)
Velocity (ft/s)
Wetted Perim (ft)
Crit Depth, Yc (ft)
Top Width (ft)
EGL (ft)
L
2
Reach (ft)
3
Friday, Aug 22 2014
= 1.48
= 15.50
= 2.50
= 6.20
= 4.15
= 1.42
= 1.75
= 2.08
Depth (ft)
2.90
PX1ril
1.90
1.40
M
0.40
-0.10
-0.60
4

Channel Report
Hydraflow Express Extension for AutoCAD® Civil 3130 2013 by Autodesk, Inc.
CB #59 TO CB #58
Q (cfs)
Circular
Area (sqft)
Diameter (ft)
= 2.00
Invert Elev (ft)
= 876.80
Slope ( %)
= 0.50
N -Value
= 0.012
Calculations
EGL (ft)
Compute by:
Known Q
Known Q (cfs)
= 17.50
Elev (ft) Section
i 879.00
878.50
878.00
877.50
877.00
876.50
876.00
Friday, Aug 22 2014
Highlighted
Depth (ft)
= 1.66
Q (cfs)
= 17.50
Area (sqft)
= 2.79
Velocity (fUs)
= 6.27
Wetted Perim (ft)
= 4.59
Crit Depth, Yc (ft)
= 1.51
Top Width (ft)
= 1.50
EGL (ft)
= 2.27
D 1 2 3
Reach (ft)
Depth (ft)
2.20
1.70
1.20
0.70
0.20
115416141
' -080
4

Channel Report
Hydraflow Express Extension for AutoCAD® Civil 3CO2013 by Autodesk, Inc.
CB #58 TO CB #67
Q (cfs)
Circular
Area (sqft)
Diameter (ft)
= 3.00
Invert Elev (ft)
= 876.20
Slope ( %)
= 0.50
N -Value
= 0.012
Calculations
EGL (ft)
Compute by:
Known Q
Known Q (cfs)
= 20.80
Elev (ft)
C_ _ 880.00
879.00
878.00
I:}'1AIR
876.00
875.00
0
Section
Friday, Aug 22 2014
Highlighted
Depth (ft)
= 1.33
Q (cfs)
= 20.80
Area (sqft)
= 3.04
Velocity (ft/s)
= 6.85
Wetted Perim (ft)
= 4.38
Crit Depth, Yc (ft)
= 1.47
Top Width (ft)
= 2.98
EGL (ft)
= 2.06
1.
2 3
Reach (ft)
4
Depth (ft)
3.80
MR,
1.80
r :s
-0.20
1.20
5

Channel Report
Hydraflow Express Extension for AutoCAD® Civil 3139 2013 by Autodesk, Inc.
FrWay, Aug 22 2014
CB #55 TO CB #54
Circular
Highlighted
Diameter (ft)
= 1.25
Depth (ft)
= 0.78
Q (cfs)
= 3.500
Area (sqft)
= 0.81
Invert Elev (ft)
= 895.20
Velocity (ft/s)
= 4.33
Slope ( %)
= 0.50
Wetted Perim (ft)
= 2.28
N -Value
= 0.012
Crit Depth, Ye (ft)
= 0.76
Top Width (ft)
= 1.21
Calculations
EGL (ft)
= 1.07
Compute by:
Known Q
Known Q (cfs)
= 3.50
Elev (ft)
897.00
t:I I:Mil
.- 1I
E 101&1111
�
894.50
Section
0 1 2 3
Reach (ft)

Channel Report
Hydraflow Express Extension for AutoCAD® Civil 3102013 by Aulodesk, Inc.
CB #54 TO CB #53
Q (cfs)
Circular
Area (sqft)
Diameter (ft)
= 1.75
Invert Elev (ft)
= 883.60
Slope ( %)
= 7.34
N -Value
= 0.012
Calculations
EGL (ft)
Compute by:
Known Q
Known Q (cfs)
= 7.60
Elev (ft) Section
886.00
885.50
*141117
884.50
IZ
883.50
(-883.00
FrWay, Aug 22 2014
Highlighted
Depth (ft)
= 0.48
Q (cfs)
= 7.600
Area (sqft)
= 0.54
Velocity (fUs)
= 14.11
Wetted Perim (ft)
= 1.93
Crit Depth, Yc (ft)
= 1.02
Top Width (ft)
= 1.56
EGL (ft)
= 3.57
Depth (ft)
2.40
1.90
1.40
M
[O1<[r;
-0.10
0 1 2 3
Reach (ft)
4

Channel Report
Hydraflow Express Extension for AutoCAD® Civil 3D® 2013 by Autodesk, Inc.
CB #65 TO CB #64
Circular
Diameter (ft) = 1.25
Invert Elev (ft) = 886.30
Slope ( %) = 0.50
N -Value = 0.012
Calculations
Compute by: Known Q
Known Q (cfs) = 0.70
Elev (ft)
888.00
887.50
887.00
M; M 11:
:- e
885.50
Friday, Aug 22 2014
Highlighted
Depth (ft)
= 0.32
Q (cfs)
= 0.700
Area (sqft)
= 0.25
Velocity (ft/s)
= 2.79
Wetted Perim (ft)
= 1.33
Crit Depth, Yc (ft)
= 0.33
Top Width (ft)
= 1.09
EGL (ft)
= 0.44
Section
0 1 2 3
Reach (ft)

Channel Report
Hydraflow Express Extension for AutoCAD® Civil 3D® 2013 by Aulodesk, Inc.
CB #64 TO CB #63
Circular
Diameter (ft) = 1.25
Invert Elev (ft) = 885.40
Slope ( %) = 0.50
N -Value = 0.012
Calculations
Compute by: Known Q
Known Q (cfs) = 1.60
Elev (ft)
88.00
E:IY:>tM]
885.50
E:I Mllif
Friday, Aug 22 2014
Highlighted
Depth (ft)
= 0.49
Q (cfs)
= 1.600
Area (sqft)
= 0.45
Velocity (ft/s)
= 3.57
Wetted Perim (ft)
= 1.69
Crit Depth, Yc (ft)
= 0.51
Top Width (ft)
= 1.22
EGL (ft)
= 0.69
Section
0 1 2 3
Reach (ft)

Channel Report
Hydraflow Express Extension for AutoCAD® Civil 3D® 2013 by Autodesk, Inc.
CB #63 TO CB #51
Q (cfs)
Circular
Area (sgft)
Diameter (ft)
= 1.25
Invert Elev (ft)
= 884.90
Slope ( %)
= 0.50
N -Value
= 0.012
Calculations
EGL (ft)
Compute by:
Known Q
Known Q (cfs)
= 2.00
Elev (ft)
887.00 —
[1-1-1-11081111
f
'.:I :b' 1111
I
` 884.00
Section
Friday, Aug 22 2014
Highlighted
Depth (ft)
= 0.56
Q (cfs)
= 2.000
Area (sgft)
= 0.54
Velocity (ft/s)
= 3.74
Wetted Perim (ft)
= 1.84
Crit Depth, Yc (ft)
= 0.57
Top Width (ft)
= 1.24
EGL (ft)
= 0.78
Depth (ft)
2.10
1.60
1.10
e -le
0.10
Q1M1(11
-0.90
0 1 2 3 4
Reach (ft)

Channel Report
Hydraflow Express Extension for AutoCAD® Civil 31)8 2013 by Autodesk, Inc.
CB #52 TO CB #51
Q (cfs)
Circular
Area (sqft)
Diameter (ft)
= 1.25
Invert Elev (ft)
= 884.90
Slope ( %)
= 0.80
N -Value
= 0.012
Calculations
EGL (ft)
Compute by:
Known Q
Known Q (cfs)
= 2.90
Elev (ft) Section
887.00
886.50
E:II:1111112
885.50
Friday, Aug 22 2014
Highlighted
Depth (ft)
= 0.60
Q (cfs)
= 2.900
Area (sqft)
= 0.59
Velocity (ft/s)
= 4.95
Wetted Perim (ft)
= 1.92
Crit Depth, Yc (ft)
= 0.69
Top Width (ft)
= 1.25
EGL (ft)
= 0.98
Depth (ft)
2.10
1.60
1.10
.�
0.10
-0.40
' I I -0 90
J 1 2 3
Reach (ft)
4

Channel Report
Hydraflow Express Extension for AutoCAD® Civil 31302013 by Autodesk, Inc.
CB #51 TO JB #50
Circular
Diameter (ft)
= 2.00
Invert Elev (ft)
= 884.30
Slope ( %)
= 0.50
N -Value
= 0.012
Calculations
Compute by:
Known Q
Known Q (cfs)
= 7.80
Elev (ft)
C 887.00
886.50
885.50
M -M—Y17
884.00
`- 883.50
0
Section
Highlighted
Depth (ft)
Q (cfs)
Area (sqft)
Velocity (fUs)
Wetted Perim (ft)
Crit Depth, Yc (ft)
Top Width (ft)
EGL (ft)
1
2
Reach (ft)
9
Riley, Aug 22 2014
= 0.94
= 7.800
= 1.46
= 5.34
= 3.03
= 0.99
= 2.00
= 1.38
Depth (ft)
2.70
2.20
1.70
1.20
0.70
0.20
-0.30
-0.80
4

Channel Report
Hydraflow Express Extension for AutoCAD® Civil 3D® 2013 by Autodesk, Inc.
JB #50 TO JB #66
Q (cfs)
Circular
Area (sqft)
Diameter (ft)
= 2.00
Invert Elev (ft)
= 884.10
Slope (%)
= 0.50
N -Value
= 0.012
Calculations
EGL (ft)
Compute by:
Known Q
Known Q (cfs)
= 7.80
Elev (ft)
( 887.00
886.50
886.00
885.50
885.00
884.50
&I'L91II]
883.50
0
Section
Friday, Aug 22 2014
Highlighted
Depth (ft)
= 0.94
Q (cfs)
= 7.800
Area (sqft)
= 1.46
Velocity (ft/s)
= 5.34
Wetted Perim (ft)
= 3.03
Crit Depth, Yc (ft)
= 0.99
Top Width (ft)
= 2.00
EGL (ft)
= 1.38
1 2 3
Reach (ft)
Depth (ft)
2.90
2.40
1.90
1.40
0.90
Ux[C
-0.10
-0.60
4

Channel Report
Hydraflow Express Extension for AutOCADO Civil 3136 2013 by Autodesk, Inc.
JB #66 TO CB #53
Q (cfs)
Circular
Area (sgft)
Diameter (ft)
= 2.00
Invert Elev (ft)
= 883.60
Slope ( %)
= 0.50
N -Value
= 0.012
Calculations
EGL (ft)
Compute by:
Known Q
Known Q (cfs)
= 7.80
Elev (ft) Section
886.00
884.50
GI:UMM
883.50
883.00
FrAay, Aug 22 2014
Highlighted
Depth (ft)
= 0.94
Q (cfs)
= 7.800
Area (sgft)
= 1.46
Velocity (ft/s)
= 5.34
Wetted Perim (ft)
= 3.03
Crit Depth, Yc (ft)
= 0.99
Top Width (ft)
= 2.00
EGL (ft)
= 1.38
Depth (ft)
2.40
1.90
fIIE[1I
M
limit"
-0.10
] 1 2 3
Reach (ft)
4

Channel Report
Hydraflow Express Extension for AutoCAD@ Civil 3D@2013 by Autodesk, Inc.
CB #53 TO CB #67
Q (cfs)
Circular
Area (sqft)
Diameter (ft)
= 2.00
Invert Elev (ft)
= 876.20
Slope ( %)
= 8.50
N -Value
= 0.012
Calculations
EGL (ft)
Compute by:
Known Q
Known Q (cfs)
= 18.60
Elev
879.00
878.50
878.00
1:YOA.111
877.00
876.50
876.00
875.50
ft) Section
— 77
Friday, Aug 22 2014
Highlighted
Depth (ft)
= 0.70
Q (cfs)
= 18.60
Area (sqft)
= 0.99
Velocity (ft/s)
= 18.84
Wetted Perim (ft)
= 2.54
Crit Depth, Yc (ft)
= 1.56
Top Width (ft)
= 1.91
EGL (ft)
= 6.22
Depth (ft)
2.80
2.30
1.80
1.30
0.80
0.30
-0.20
0 1 2 3
Reach (ft)
4

Channel Report
Hydraflow Express Extension for AuloCAD® Civil 3D® 2013 by Autodesk, Inc.
CB #67 TO CB #57
Q (cfs)
Circular
Area (sqft)
Diameter (ft)
= 3.00
Invert Elev (ft)
= 875.60
Slope ( %)
= 0.50
N -Value
= 0.012
Calculations
EGL (ft)
Compute by:
Known Q
Known Q (cfs)
= 40.90
Elev (ft)
879.00
878.00
877.00
875.00
874.00
0
Section
Friday, Aug 22 2014
Highlighted
Depth (ft)
= 2.03
Q (cfs)
= 40.90
Area (sqft)
= 5.10
Velocity (ft/s)
= 8.02
Wetted Perim (ft)
= 5.80
Crit Depth, Yc (ft)
= 2.09
Top Width (ft)
= 2.80
EGL (ft)
= 3.03
i
2 3
Reach (ft)
4
Depth (ft)
3.40
2.40
1.40
0.40
M.0
-160
5

Channel Report
Hydraflow Express Extension for AutoCAD® Civil 3138 2013 by Autodesk, Inc.
:;B #57 TO NEW
JB #57
Circular
Diameter (ft)
= 3.00
Invert Elev (ft)
= 875.30
Slope ( %)
= 0.50
N -Value
= 0.012
Calculations
Compute by:
Known Q
Known Q (cfs)
= 47.50
Elev (ft)
879.00
878.00
877.00
876.00
875.00
874.00
0
Section
Highlighted
Depth (ft)
Q (cfs)
Area (sqft)
Velocity (ft/s)
Wetted Perim (ft)
Crit Depth, Yc (ft)
Top Width (ft)
EGL (ft)
1
2 3
Reach (ft)
4
Wednesday, Aug 27 2014
Depth (ft)
3.70
2.70
1.70
0.70
11119I111
-1.30
5
= 2.29
= 47.50
= 5.80
= 8.18
= 6.39
= 2.25
= 2.54
= 3.33

Channel Report
Hydraflow Express Extension for AutoCAD0 Civil 3D® 2013 by Autodesk, Inc.
NEW JB #57 TO NEW JB 57A
Circular
Diameter (ft)
= 3.00
Invert Elev (ft)
= 874.40
Slope ( %)
= 0.50
N -Value
= 0.012
Calculations
Compute by:
Known Q
Known Q (cfs)
= 47.50
Elev (ft)
(, s7s.00
877.00
875.00
873.00
0
Section
Highlighted
Depth (ft)
Q (cfs)
Area (sqft)
Velocity (ft/s)
Wetted Perim (ft)
Crit Depth, Yc (ft)
Top Width (ft)
EGL (ft)
1
2 3
Reach (ft)
4
Wednesday, Aug 27 2014
Depth (ft)
3.60
2.60
1.60
W M
-0.40
-140
5
= 2.29
= 47.50
= 5.80
= 8.18
= 6.39
= 2.25
= 2.54
= 3.33