HomeMy WebLinkAboutFALCON RIDGE PUD - FINAL - 2-94G - SUBMITTAL DOCUMENTS - ROUND 1 - DRAINAGE REPORTJuly 1994
Gutter Capacities
For: Sandcreek Assoc., Falcon Ridge
By: Stewart and Associates
Street X-Slope ft/ft = 0.02
Gutter Slope ft/ft = 0.005
Mannin 's "N" Value = 0.016
Street Name: "v-totu VAty. Location: s?A-mb.6. , Design Flow: cA
Depth at Face
Of C&G ft
Depth at
Flow Line ft
Wetted
Per, ft
Flow Area
s .ft.
Spread 'T'
ft)
Flow Vol.
(cfs)
Velocity
(ft/sec
0.00
0.11
1.55
0.08
1.55
0.3
4.05
0.05
0.16
2.70
0.23
4.22
0.9
4.07
0.10
0.21
2.84
0.51
6.90
1.9
3.80
0.15
0.26
.2.95
0.92
9.57
3.4
3.71
0.20
0.31
3.05
1.46
12.24
5.4
3.72
0.251
0.36
3.14
2.14
14.91
8.1
3.79
0.301
0.41
3.23
2.96
17.59
11.5
3.88
0.311
0.42
3.25
3.131
18.12
12.2
3.91
Street X-Slope ft/ft = 0.02
Gutter Slope ft/ft = 0.01
Mannin 's "N" Value = 0.016
Street Name: t"ACC.w-) Location: 00 - 1
Z-y2
Design Flow: Ii,3�
Depth at Face
Of C&G ft
Depth at
Flow Line ft
Wetted
Per. ft
Flow Area
s .ft.
Spread 'T
ft)
Flow Vol.
(cfs)
Velocity
(f /sec
0.00
0.11
1.55
0.08
1.55
0.5
5.73
0.05
0.16
2.70
0.23
4.22
1.3
5.76
0.10
0.21
2.84
0.51
6.90
2.7
5.38
0.15
0.26
2.95
0.92
9.57
4.8
5.25
0.20
0.31
3.05
1.46
12.24
7.7
5.26
0.25
0.361
3.14
2.14
14.91
11.5
5.36
0.30
0.411
3.23
2.96
17.591
16.21
5.49
0.31
0.421
3.25
3.131
18.121
17.31
5.52
Manning's Equation for the Theoretical Capacity
of Non - Symetrical Triangular Section
0.016 = Side Slope 1 1 0.013 = Manning's (n)
0.016 = Side Slope 2 mjlllllllllllllll''''1111111111111111117 This Section
Millillillilillillillillill
0.01 = Channel Slope ill TYPICAL
Flow Depth
Intercept
Area 1
1(ft
Intercept
Area 2
Total Discharge
(ft/ft)
(ft from CL)
(sq/ft)
from CL)
(sq/ft)
This Section (cfs)
0.05
3.13
0.08
3.13
0.08
0.15
:0 10
6.25
:::0 3.1
6.25
0.31
97
0.15
9.38
0.70
9.38
0.70
2.86
1.25
12.50
1.25
6a 6
0.25
15.63
1.95
15.63
1.95
11.16
.::0.30
18 75
... 281
18.75
.81::,::
0.35
21.88
3.831
21.88
3.83
27.38
..,0 0
.4
::.,;.:::25.00
.5.00
5.00
39;09
0.45
28.13
6.331
28.13
6.33,
53.51
0 50
3.1,25
7.81:1:
...... .. ....
.............. 70a87
0.016 = Side Slope 1 0.013 = Manning's (n)
0.016 = Side Slope 2 This �Secltion
0.005 = Channel Slope III TYPICAL
Intercept
Area 1
Intercept
Area 2
Total Discharge
't from CL)
(sq/ft)
(ft from CL)
(sq/ft) I
This Section (cfs)
3.13
0.08
3.13
0.08
0.1
6.25. '
0.31.
6.25
.0.31:
9.38
0.70
9.38
0.70
2.02
1 2 . 5 0
1.25
-:12.50,:
2 5..
4.35:
15.63
1.95
15.63
1.95
7.89
18.75
8 2. ll
18.75
2.81
12.
21.88
3.83
21.88
3.83
19.36
25 00
5.00
25.00:r:..
5 00.
27.64.9
28.13
6.331
28.13
6.33
37.84
31.25
7.81.1
3 1.25
:.-r.............7.81
50.1
NOTE: - The manning's (n) Value is between the typical
- These two section shown are examples of possible design concerns
- Pan side slopes are inclicitive of 8-ft wide street cross pans
Manning's Equation for the Theoretical Capacity
of Non - Symetrical Triangular Section
0.010 = Side Slope 1 0.060 = Manning's
0.010 =Side Slope 2 This Section
0.010 = Side Slope 1 0.060 = Manning's (n)
0.010 = Side Slope 2 I This Section
1 0.005 = Channel Slope III TYPICAL 0.01 = Channel Slope j TYPICAL
Flow Depth
(ft/ft)
Intercept
(ft from qL I
Area 1
(sq/ft)
Intercept
(ft from CL)
Area 2
(sq/ft)
Total Discharge
This Section (cfs)
Intercept
(ft from CL
Area 1
s /ft
Intercept
ft from CL)
Area 2
(sq/ft)
Total Discharge
This Section (cfsl
0.05
5.00
0.13
5.00
0.13
0.04
5.00
0.13
5.00
0.13
O.0
.�! :.�Ojo:
050
AD 00
z:::�::�0.50.
024
0.. so:,,.,.j
0.00
>050
0.15
15.00
1.13
15.00
1.13
0.70
15.00
1.13
15.00
1.13
0.99
::..0.20
20.00
2. 00
2000
;
�z. 2.00
1.51:
.,:20100.1.
..�:.ZOO
z�� 20.00T
.. ..... -
Z00,
9 �: 13:
0.25
25.00
3.13
25.00
3.13
2.74
0'-
25.001
3.131
25.00
3.13
3.87
0.30,.:,:,:,
30.00
4.50
::.::,::30.00
::.:.-�:4�50
4.45
. ..... -
9
0.35
35.00
6.13
35.00
6.13
6.71
35.001
6.131
35.00
6.13
9.49
,040
40.00
.::40.00
9 58
�40.00
8.00
800
-
13
0.45
45.00
10.13
45.00
10.13
13.12
45.001
10.131
45.00
10.13
18.55
0�50]:.
1Z50
2.501
0
....
112.501:��.,:
. .. .....
2 4.57
NOTE: - The manning's (n) Value is between the typical
- These two section shown are examples of possible design concerns
- Pan side slopes are indicitive of 2-ft wide backlot pans
DRIVE OVER C & G AND INLET SIZING
THEORETICAL FLOW CAPACITY VS. FLOW DEPTH
Equation used is Q = .56 (Z/n) (S ^ .5) (Y ^ 8/3)
When solved for depth Y = ((Q * n) / (.56) Z (S) ^ .5) ^ 3/8
1.40 = Inlet Capacity (cfs/ft) Without Reduction factor
SDDCCS (Figure 5-2) enc& .wk3
St. Name/Inlet ID E.Side FALCON / INLET DN-2 I Type Of Street: Residential / Initial Storm
11.30 = Q flow in cfs 0.016 = n Mannin s 0.020 = Sx X—slo e
0.005 = S (st. slope) 0.85 = Init. Red. Fact. 50.00 = Z (1/Sx)
BUILD 12' INLET
St. Name/Inlet IDJ W.Side FALCON/ INLET DN-2 I Type Of Street: Residential / Initial Storm
0.90 = Q flow in cfs 0.016 = n Mannin s 0.020 = Sx X—slope)
0.005 = S (st. slope) 0.80 = Init. Red. Fact. 50.00 = Z (1 /Sx)
BUILD 4' INLET
STEWART&kSSOuATES
Consulting Engineers and Surveyors
103 S. MELDRUM, F� COLLINS, CO 80521
PH. 482-9331 FAX 482-9382
By: Date: - Client: 5a�I,Z--ree`7 Sheet No. of
Project: / o� %C i �a �� / . 1� 0
Subject:
DI�E.PL/�ti/� Z)49071�-5 GD�Tr
�2T/-/ 7110
LU"siw /v , 7/J xe- 41
Ila r
�
G
400
STEWART&ASSOuATES
Consulting Engineers and Surveyors
103 S. MELDRUM, R COLLINS, CO80521
PH. 482-9331 FAX 482-9382
By: Date: Client: Sheet No. of _
Project: zz::� xCpo e
Subject:
Ucsyh S��h z•
/
i
2sv � � c5-= o 7 7o
Cia�s
�rcrc�
�7so cs=��
7D fc LSD
eO 6. - //
sr���fi 5w9
DATA CONSTANTS
Type i Location
FLOWLINE
WIDTH (ft)
CROSS
SLOPE (ft)
STREET
SLOPE (ft)
YARD
SLOPE (ft)
WALK
WIDTH (ft)
DEPTH @
CURB F.L.
CURB
HEIGHT (ft)
CROWN REDUCT'N
ELEV. FACTOR
36.00
0.020C
0.0060
0.020
5.00
0.86
0.50
100.001 0.80
CALCULATED CONSTANTS
WETTED
PERIMETER
WEIGHT'D
IMANNINGS1
I TOP
WIDTH
AREA
OF FLOW
97.011
0.02581
96.00
41.98
CALCULATED HYDRAULICS
THEO.
CAPACITY cfs
I ALLOW
CAPACITY
I WATER
I ELEV.
VELOCITY
s
107.181
85.741
100.50
0.88
-f—
G lKg N 15,I�Tk1'
-
i
�i - 1l55YVA,K WI7'N
I'
i
DATA CONSTANTS
Type i Location Ze. Air ftt,
p
FLOWLINE
WIDTH (ft)
CROSS
SLOPE (ft)
STREET
SLOPE (ft)
YARD
SLOPE (ft)
WALK
WIDTH (ft)
DEPTH @
CURB F.L.
CURB
HEIGHT (ft)
CROWN
ELEV.
REDUCT'N!
FACTOR
36.001
0.0200
0.0050
0.020
5.00
0.86
0.50
100.00
0.80
CALCULATED CONSTANTS
WETTED
PERIMETER
WEIGHT'D TOP
MANNINGS WIDTH
AREA
OF FLOW
97.011
0.0258 96.00
41.98
CALCULATED HYDRAULICS
THEO.
CAPACITY cfs
I ALLOW
CAPACITY
WATER
ELEV.
VELOCITY
s
97.841
78.271
100.501
0.81
SUJ9� '
DATA CONSTANTS
Type/ Location (Z��,,
fLlm e-
FLOWLINE
WIDTH (ft)
CROSS
SLOPE (ft)
STREET
SLOPE (ft)
YARD
SLOPE (ft)
WALK
WIDTH (ft)
DEPTH @
CURB F.L.
CURB
HEIGHT (ft)
CROWN
ELEV.
REDUCT'N
FACTOR
36.00
0.0200
0.00601
0.020
5.001
0.86
0.50
100.001
0.80
CALCULATED CONSTANTS
WETTED
PERIMETER
WEIGHT'D I TOP
MANNINGS1 WIDTH
AREA
OF FLOW
97.011
0.02581 96.001
41.98
CALCULATED HYDRAULICS
THCITYEO.
CAPAcfs
ALLOW
CAPACITY
WATER
ELEV.
VELOCITY
s
107.18
85.74
100.501
0.88
CUK5 !-!S�1,-'7H-r -
I �
I
5i1UiK wID'u �I E—
I
DATA CONSTANTS
Type i Location z>a0r .,r-
FLOWLINE
WIDTH (ft)
CROSS
SLOPE (ft)
I STREET
I SLOPE (ft)
YARD
SLOPE (ft)
WALK
WIDTH (ft)
DEPTH @
CURB F.L.
CURB
HEIGHT (ft)
CROWN I REDUCT'N
ELEV. FACTOR
36.001
0.0200
-0.00501
0.020
5.00
0.86
0.50
100.001 0.80
CALCULATED CONSTANTS
WETTED
PERIMETER
WEIGHT'D
IMANNINGS
TOP
WIDTH
AREA
OF FLOW
97.011
0.0258
96.00
41.98
CALCULATED HYDRAULICS
THEO.
CAPACITY cfs
I ALLOW
CAPACITY
I WATER
I ELEV.
VELOCITY
s
97.841
78.271
100.501
0.81
DRAINAGE CRITERI MANUAL
RUI4OFF
50
30
F- 20
Z
w
U
tz
n 10
Z
w
a
O 5
w
cc 3
O
U 2
CC)
w
F-
a
t
1
3
0
�P =
4 �� �Y
tl
_ o-�?
Q b
—QY
o
A
ti
J
V
4'0
A. m o 3
- y L
e y
o
Y
4
4
O
Qr
--I
TIT
.2 .3 .5 11 2' 3 5 10 20
VELOCITY IN FEET PER SECOND
FIGURE 3-2. ESTIMATE OF AVERAGE FLOW VELOCITY FOR
. ; I USE WITH . THE RATIONAL FORMULA.
*MOST FREQUENTLY OCCURRING "UNDEVELI)PED"
LAND SURFACES IN THE DENVER REGION.
REFERENCE: "Urban Hydrology For Small Watersheds" Technical
Release No. 55, USDA, SCS Jan. 1975.
5 -1-84
URBAN DRAINAGE & FLOOD CONTROL DISTRICT
No Text
I'St]RRASIN:lTO.C..11100vr1
D. Pnt.
N. POND
Slope
C Cf
Length
(feet )
Overl-Tc
(min.)
Vel.Chan
(ft/sec.)
Tc Chan.
(min.)
Tc Total
(min.)
COMMENTS
4.001
0.561
180.001
8.51
Tc (100)
0.001
1 0.001
1 0.001
0.0
8.5
1 NGST. OVERL+CHANNEL
0.45 = Runoff C 1.00 = Ut 2.10 1.25 =Ut 1UU
D. Pnt.
Area
(acres)
C * Cf
I (2yr.)
(in/hr)
I (10yr.)
(in/hr)
I (100yr.)
(in/hr)
Basin 0
(cfs)
Comb. Q
(cfs)
COMMENTS
3.06
0.45
2.65
3 65
3.6
2 yr. runoff
0.45
4.66-
6.W11
r. runoff
0.561
7.00
12.05 11
2 1n
�-iimooyr. runoff
0.45 = C 1.00 =Cf(zlo) 1.25 =Cf(100)
ILL22MLLJ
SUBBASIN T.O.C.MDT)
D. Pnt.
DS-2
Slope
C Cf
Length ()
I feet
Overl- Tc
(min.)
Vel.Chan
(ft/sec.)
Tc Chan.
(min.)
Tc Total
(min.)
COMMENTS
4.00
0.561
180.001
8.5
Tc (100)
0.00
0.001
2.00
0.0
8.51
LNGST. OVERL.+CFIANNEL
0.45 = Runoff C 1.00 = Cf 2,10 1.25 =Cf 100
D. Pnt.
Area
(acres)
C Cf
I (2yr.)
(in/br)
I (10yr.)
(in/hr)
I (100yr.)
(in/hr)
Basin Q
(cfs)
Comb. 0
(cfs)
COMMENTS
0.56
0.451
2.25
0.57
0.6
2 yr. runoff
0.451
3.90
0.98
1.01
10 yr. runoff
0.561
6.40
202
011
100 yr. runoff
0.45 = C 1.00 =Cf(zlo) 1.25 =Cf(100)
ILLLMLL�j
L
-t-UBBASIN: T. O.C,-:
D. Pnt
DN-5
Slope
(0/0
C Cf
Length
(feet
Overl-Tc
(min.)
Vel.Chan
(ft/sec.)
Tc Chan.
min.
Tc Total
min.)
COMMENTS
v j
6.00
0.56
110.001
5.8
Tc (100)
1.80
480.001
1.75
4.6
1 .4 0
LNGST. OVERL+CHANNEL
0.45 = Runoff C 1.00 = Cf 2,10 1.25 =Cf 100
SUBBASIN T.O.0 . .. .
D. Pnt
DN-1
Slope C Cf
N
Length
feet
Over- Tc
Vel.Cha
ft/sec.
Tc Chan.
min.
Tc o )
min.
COMMENTS
K
5.001 6.56
240.001
9.1
Tc (100)
1.101
180.001
200
1.5
10.6
LNGST. OVERL+CHANNEL
0.45 = Runoff C 1.00 = Cf 2,10 1.25 =Cf 100
D. Pnt
Area
(acres)
C * Cf
I (2yr.) I (10yr.)
(in/hr)
I (100yr.)
(in/hr)
Basin Q
(cfs)
Comb. 0
(cfs) I
COMMENTS
K
1.76
0.45
2401
1.90
F7777T1 9R
2 yr. runoff
0.45
4.35
3.45
: . ::::: i:: 'I A
10 yr. runoff
0.56
7.00
E-9-3
11, .911
100 yr. runoff
0.45 = C 1.00 =Cf 2,10 1.25 =Cf 100
LLL_K- _ :<:
SUBBASINT;O.C. I(I!Rr)...,
D. Pnt
DN-2
Slope C Cf
Length Overl- Tc
(feet ) (min.)
Vel.Chan
(ftlsec.)
Tc Chan.
(min.)
Tc Total
(min.)
COMMENTS
I
L
2.001 0.56
70.001 6.7
Tc 100)
(
3.101
190.001
3.50
0.9
.. �: 7ZI
LNGST. OVERL+CHANNEL
0.45 = Runoff C 1.00 = Cf 2,10 1.25 =Cf 100
D. Pnt.
Area
(acres)
C * Cf
I (2yr.)
I (I 0yr.)
(in/hr)
I (100yr.)
(in/hr)
Basin Q
(cfs)
Comb. Q
(cfs)
COMMENTS
0.301
0.45
2-701
0.36
0.411
2 yr. runoff
0.45
4.70
O.M
0.611
10 yr. runoff
0.56
7.00
100 yr. runoff
0.45 = C 1.00 =Cf 2,10 1.25 =Cf(100)
4.90 = Area(ac) this page
SUBBASIN O.C.
D. Pnt
DN-3
Slope
(0/0)
c Cf
Length
(feet)
OverLTc
(min.)
Vel.Chan
(ft/sec.)
Tc Chan.
(min.)
Tc Total
(min.)
COMMENTS
3.50
0.56
80.001
5.9
Tc (100)
1.00
500.001
2.00
4.2
LNGST. OVERL+CHANNEL
0.45 = Runoff C 1.00 = Cf 2,10 1.25 =Cf 100
D. Pnt.
Area
(acres)
C Cf
11 2yr.)
(in/hr)
I (10yr.)
(in/hr)
I (100yr.)
(in/hr)
Basin Q
(cfs)
Comb. Q
1�%
cfs
COMMENTS
0.85
0.45
250
0.96
2 r. runoff
y
4.
1.681
10 yr. runoff
0.56
�j
1 7.00
100 yr. runoff
0.45 = C 1.00 =Cf 2,10 1.25 =Cf(100)
SUBBASlN..T;O,C.::..(IWfr).....
D. Pnt
DN-3
Slope
N
c Cf
Length OverL Tc
(feet) (min.)
Vel.Chan
(ft/sec.)
Tc Chan.
(min.)
Tc Total
(min.)
COMMENTS
3.50
0.56
80.001 5.9
Tc 100)
1.00
500.001
200
4.2
LNG,4.7). OVERL+CFIANNEL
0.45 = Runoff C 1.00 = Cf 2,10 1.25 =Cf 100
D. Pnt.
Area
(acres)
c Cf
I (2yr.)
in/hr
:Z/hrq
I (10yr.)
Ci n /h r)
I (100yr.)
(m/hr)
Basin Q
Comb. Q
(cfs)
COMMENTS
H
1.64
0.45
2.50
1.85
%3.25
�.1.811
2 yr. runoff
0.45
3.21
10 yr. runoff
0.56
7.00
6.46
11
100 yr. runoff
0.45 = C 1.00 =Cf 2,10 1.25 =Cf 100
ILILLtt�
D. Pnt.
DN-3
Slope
N
C Cf
I
Length
Ifeet
Overl- Tc
min.)
Vel.Chan
(ft/sec.
Tc Chan.
min.
Tc Total
min.)
COMMENTS
3.50
0.561
80.001
5.9
Tc (100)
1.001
500.001
2.00
4.2
LNGST. OVERL+CHANNEL
0.45 = Runoff C 1.00 = Cf 2,10 1.25 =Cf 100
D. Pnt.
Area
acres
C * Cf
I (2yr.) I (10yr.)
(in/hr) (in/br)
I (100yr.)
(in/br)
Basin Q
cfs
Comb. Q
GfS
COMMENTS
1.231
0.45
2501
1.3811
2 yr. runoff
0
4.40
2.44
s2.4.1
10 yr. runoff
1 0.561
1
7.00
4.E4
�.VA a
-li
100 yr. runoff
0.45 = C 1.00 =Cf 2,10 1.25 =Cf 100
ILLLiLLLJ
J. I;e = Area(ac) mis page
11
D. Pnt.
DS-2
Slope
C * Cf
Length
(feet)
Overl-Tc
(min.)
Vel.Chan
(ft/sec-)
Tc Chan.
(min.)
Tc Total
(min.)
COMMENTS
3.40
0.561
175.001
8.81
Tc (100)
1.00
1 500.001
1 1.501
5.6
.14 .4
LNGST. OVERL+CHANNEL
0.45 = Runoff C 1.00 = Cf 2,10 1.25 =(;t 100
D. Pnt.
Area
(acres)
C Cf
I (2yr.)
(in/hr)
I (I 0yr.)
(in/hr)
I (100yr.)
(in/hr)
Basin Q
(cfs)
Comb. 0
(cfs)
COMMENTS
0.41
0.45
2.25
2 yr. runoff
0.45
3.90
10 yr. runoff
0.56
6.40
1.48
.... 1.5
ME
100 yr. runoff
0.45 C 1.00 =Cf(zlo) 1.25 =Cf 100
D
SUBBASlW.:::..O.0 .
D. Pnt.
DS-2
Slope
(0/6)
C Cf
Length
(feet)
Overl- Tc
(min.)
Vel.Chan
(ft/sec.)
Tc Chan.
(min.)
Tc Total
(min.)
COMMENTS
E
3.40
0.56
175.00
8.8
Tc (100)
1.00
500.00
3.50
2.4
LNGST.OVERL+CHANNEL-
0.45 = Runoff C 1.00 = Cf 2,10 1.25 =Cf 100
D. Pnt.
Area
(acres
7Cf
1(2yr.)
I (10yr.)
(in/br)
I (100yr.)
(in/hr)
Basin 0
(cfs)
Comb. 0
(cfs)
COMMENTS
. .........
0.83
0.40.452.251
0.84
0.8
2 yr. runoff
0.45
3.901
1.46
1.5
io yr. runoff
0.56
6.401
2.99
3.0
100 yr. runoff
0.45 = C 1.00 =Cf(zlo) 1.25 =Cf(100)
SUBBASIN OT.O.C.
D. Pnt
DN-4
Slope
(0/0)
C *7cf
Length Overl-Tc
feet) (min.)
Vel.Chan
(ft/sec.)
Tc Chan.
(min.)
Tc Total
(min.)
COMMENTS
3.00
0.56
200.001 9.91
Tc (100)
0.401
460.001
1 1.501
LNGST. OVERL+CHANNEL
0.45 = Runoff C 1.00 = Cf 2,10 1.25 =Cf 100
--5.1
1
D. Pnt.
Area
(acres)
C Cf
I (2yr.) I (I 0yr.)
(in/hr) (in/hr)
I (100yr.)
(in/hr)
Basin 0
cfs I
Comb. Q
(cfs)
COMMENTS
F
2.22
0.45
2.101
2 - 10
2- 1, 11
2 yr. runoff
0.45
3.70
3.70
1:+:::;::��:i��:::�:�i:�:::::3.711
10 yr. runoff
0.561
6.06-
7 . 49
1:::: 7.511
100 yr. runoff
0.45 = C 1.00 =Cf(zlo) 1.25 =Cf(100)
J.4b = Area(ac) tnis page
0 -.,:(00v-..,...
SUBBASIN� C. 1
DEVELOPED RUNOFF COMPUTATIONS FROM RATIONAL METHOD
Q = C x Cf x I xA
6.:-
D. Pnt.
Sloe
c Cf
Length
Overl-Tc
Vel.Chan
Tc Chan.
Tc Total
COMMENTS
DS-2
(0/0)
(feet ]l I
(min.)
(ft/sec.)
(min.)
(min.)
3.40
0.56
175.001
8.8
Tc (100)
1.00
500.001
2.00
417
13.0
LNGST. OVERL +CHANNEL
0.45 = Runoff C
1.00 = Cf 2,10
1.25 =Cf 100
D. Pnt.
Area
(acres)
C Cf
I (2yr.) I (10yr.)
in/hr (in/hr
I (100yr.)
in/hr
Basin Q
cfs
Comb. Q
cfs)
COMMENTS
1.49
0.45
2.251
1.51
1.51
2 yr. runoff
0.45
3.90
2.61
2-6
10 yr. runoff
0.56
6.40
536
5.4
yr. runoff
0.45 = C 1.00 =Cf(zlo) 1.25 =Cf(100)
SUBBASIN.....: aaci . (100yr)
D. Pnt.
DS-2
Slope
(0/0)
c Cf
Length Overl-Tc
(feet) (min.)
Vel.Chan
(ft/sec.)
Tc Chan.
(min.)
Tc Total
(min.)
COMMENTS
B
3.40
0.56
175.001 8.8
Tc (100)
1.00
500.001
2.00
4.2
i.13.0
LNGST. OVERL+CHANNEL
0.45 = Runoff C 1.00 = Cf 2,10 1.25 =Cf 100
D. Pnt.
Area
(acres)
C Cf
1(2yr.) I (10yr.)
in/hr (in/hr)
I (100yr.)
(in/hr)
Basin Q
(cfs)
Comb. Q
(cfs)
COMMENTS
0.70
0.45
2.251
0.71
2 yr. runoff
0.45
3.90
1.23
10 yr. runoff
0.56
6.40
2 52
2 5
100 yr. runoff
0.45 = C 1.00 =Cf(zlo) 1.25 =Cf 100
B
SUBBASIN..: O.C-::(10Gyr):..
D. Pnt.
DS-1
Slope C Cf Length Overl-Tc
(feet) (min.)
Vel.Chan
(ft/sec.
Tc Chan.
min.
Tc Total
min.)
COMMENTS
2.201 0.561 185.001 10.5
Tc (100)
1.761 380.001
1.50
4.2
14,
WGST. OVERL+CHANNEL
0.45 = Runoff C 1.00 = Cf 2,10 1.25 =Cf 100
D. Pnt.
Area
(acres)
C * Cf I (2yr.) I (10yr.)
(in/hr) (in/br
I (100yr.)
in/hr
Basin Q
cfs
Comb. 0
cfs
COMMENTS
3.69
0.451 2.101
3.49
3.5
2 yr. runoff
0.451 1 3.75
6.23
6:21
10 yr. runoff
0.561 1
6.00
12.45
100 yr. runoff
0.45 = C 1.00 =Cf(zlo) 1.25 =Cf 100
1::: c
o.tju = Areatac) mis page
DATE: JULY 1994
HISTORIC/DEVELOPED RUNOFF COMPS. 2/10/100 YR. STORMS
FALCON RIDGE P.U.D.
FOR: SANDCREEK ASSOCIATES
BY: Stewart &Associates
GENERAL NOTES: Velocity in a Channel per FIGURE 3-2
If C x Cf > = I then C x Cf = I (constants listed below)
For design of the developed site runoff quantities Tc(l 00) was the basis for design
B:\LORYANRO.wk3
SUBBASIN t b c
HISTORIC RUNOFF COMPUTATIONS FROM RATIONAL METHOD
0 = C x Cf x I x A
D. Pnt
Slope
(0/0)
C Cf
Length
(feet)
Overl- Tc
(min.)
Vel.Chan
(ft/sec.)
Tc Chan.
(min.)
Tc Total
(min.)
COMMENTS
2.00
0.25
840.00
36.6
Tc (100)
-0,20
1.00
0.00
1.50
0.0
.:..36.6
LNGST. OVERL+CHANNEL
= Runoff C
1.00 = Cf 2,10 1.25 =Cf 100
D. Pnt.
Area
(acres)
C * Cf
I (2yr.)
(in/hr)
I (10yr.)
I (100yr.)
(in/hr)
Basin Q
(cfs)cfs
Comb. Q
COMMENTS
A
10.00
0.20
1.30
_(in/hr)
2.60
6
2 yr. runoff
0.20
2.30
4.60
::4.611
10 yr. runoff
0.25
3.70
9.25
:19.311
100 yr. runoff
0.20 = C 1.00 =Cf 2,10 1.25 =Cf 100
:A
D. Pnt
Slope
N
C Cf
Length
(feet)
Overl- Tc
(min.)
Vel.Chan
(ft/sec.)
Tc Chan.
(min
Tc Total COMMENTS
(min.)
i:B
2.00
0.251
840.00
36.6
1 Tc (100)
0.00
1 0.001
1.50
0.00
36.61 LNGST. OVERL +CHANNEL
0.20 = Runoff C 1.00 = Cf 2,10 1.25 =Cf 100
D. Pnt
Area
(acres)
C Cf
I (2yr.)
(in/hr)
I (10yr.)
(in/br)
I (100yr.)
(in/hr)
Basin Q
cfs
Comb. Q COMMENTS
ACLS)
10.00
0.20
1.30
2.60
2-61 2 r. runoff
0.20
2.30
4.60
:::4.61 10 jr. runoff
0.251
3.70
.
925
:,o:,77:9.31 100 yr. runoff
0.20 = C 1.00 =Cf 2,10 1.25 =Cf 100
-B
LIUM = Area MIS vage
HYDROLOGIC SUMMARY
21.58 = Area To Be Detained On Site
TOTAL DEVELOPED RUNOFF
�.8
2 yr. runoff
39.21
10 yr. runoff
78.31
100 yr. runoff
DN-4 PAW:-.1-1 1-
2.1
2 yr. runoff
3.71
10 yr. runoff
7.51
100 yr. runoff
21.58 = Total project area(ac) Basins F
DN-1 INLET .
11.3
2 yr. runoff
20.01
10 yr. runoff
40.31
100 yr. runoff
Basins F, U, H, 1, J, K
DN.-2INLET.
O�.g
2 yr. runoff
1.61
10 yr. runoff
3.21
100 yr. runoff
Basins L, N
6.3
2 yr. runoff
11.11
10 yr. Runoff
22.11
100 yr. runoff
DN 5 PAN
3.1
2 yr. runoff
5.51
10 yr. runoff
11.21
100 yr. runoff
Basins J
DS
�35
2 yr. runoff
6.21
10 yr. runoff
12.51
100 yr. runoff
Basin C
DS--w2 PAN
2.6 2 yr. runoff
4.61 10 yr. runoff
9.41 100 yr. runoff
Basins F, G, H, I Basin A, B, D
STEWART&LSSOCIATES
Consulting Engineers and Surveyors
July 5, 1994
Mr. Basil Hamdan
Storm Water Utility
City of Fort Collins
P. 0. Box 580
Fort Collins, Colorado 80522
Dear Basil:
The following is the final storm drainage report for Falcon Ridge P.U.D.
The site is a proposed 19.34 acre single—family detached subdivision located
in the Southwest a of Section 36, Township 8 North, Range 69 West of the 6th
P.M. It is bounded on the north by Country Club Road, on the east by Rim Rock
Subdivision and a large metes and bounds parcel, on the south by Spaulding
Lane and on the west by a large metes and bounds parcel. The site is in the
Dry Creek Major Drainage Basin; however, the southern half of the site is a
part of the Evergreen Park Drainage Basin.
The site has an existing residence which is not a part of the subdivision,
but is included in the drainage plan. The site has a good cover of grass and
weeds. The north half of the site drains westerly from Ford Lane at an
approximate slope of 2.9%. The north half historically drains into a low area
on the easterly side of Colorado Highway 1 which will become a detention pond.
From the low area, the existing runoff discharges into the southeasterly borrow
ditch of Colorado Highway 1 and flows southwesterly to the Eaton Ditch.
The south half of the site drains southerly to Spaulding Lane and then
westerly in Spaulding Lane to the Eaton Ditch.
It is proposed to detain the difference between the two—year hisitoric
runoff and the 100—year developed runoff from the north half in the low area
and then continue to discharge into the borrow ditch at the historic rate.
Likewise, it is proposed to detain the 100—year developed runoff in a new
detention pond to be constructed in the Southwest corner of the site. It is
planned to continue to discharge at the historic rate into the north curb of
Spaulding Lane. A chase under the proposed walk and through the existing curb
will carry the detained flows to Spaulding Lane.
James H. Stewart
and Associates, Inc.
103 S. Meldrum Street
P.O. Box 429
Ft. Collins. CO 80522
303/482-9331
Fax 303/482-9382
Falcon Ridge P.U.D.
Paye 2
The site will be divided into 14 developed sub —basins that are shown on
the grading and drainage plan. Both detention ponds will be used as
sedimentation basins. Rock filters and straw bales will also be used to filter
sediment. Disturbed areas that will not be constructed on soon will be
reseeded.
The grading and drainage report and the runoff calculations are included
as a part of this report. If you have any questions regarding this project,
please call.
This drainage report and the design of the drainage system are in
compliance with the City of Fort Collins storm drainage specifications and
criteria.
Si ncerel y �.�`"`p +�U'•a
IST
i
Ri chard A. Rutherford, P. E. & L. S. =*; eJ 2
President
rar/jm
r•Q
J
FINAL DRAINAGE REPORT
FOR
FALCON RIDGE P.U.D.
JULY 5. 1994
STEWART & ASSOCIATES. INC.
103 SOUTH MELDRUM STREET
FORT COLLINS, COLORADO 80521
303/482-9331