HomeMy WebLinkAboutDrainage Reports - 07/06/1988 (2)I
LJ
111
RWINC
Engineering Consultants
'
MASTER DRAINAGE STUDY
FOR
WILD WOOD FARM
PREPARED FOR:
'
G.T. LAND COLORADO INC.
3555 STANFORD ROAD, SUITE 100
FORT COLLINS, CO 80525
PREPARED BY:
'
RBD, INC. ENGINEERING CONSULTANTS
2900 SOUTH COLLEGE AVENUE
FORT COLLINS, CO 80525
1
'
INDEX
INTRODUCTION
1
'
LOCATION
DESCRIPTION
DESIGN CRITERIA
1
DESIGN PROCEDURE
2
SUMMARY
2
'
REFERENCES
3
APPENDIX
VICINITY MAP
Al
'
10 YEAR STORM PRELIMINARY
DETENTION POND SIZING
A2-A4
100 YEAR STORM PRELIMINARY DETENTION POND SIZING
A5-A7
POCKET
'
MASTER DRAINAGE PLAN
I
'
LOCATION
Wild Wood Farm is located in the Northeast quarter of Section 5,
Township 6 North, Range 69 West of the 6th Principal Meridian in
'
Fort Collins, Colorado. This site is at the southwest corner of
the intersection of Harmony Road and County Road 9 (see vicinity
'
map).
This site is located within the McClellands Basin. This major
basin is identified in the McClellands Basin Master Drainage
'
Plan, by Greenhorn and O'Mara, Inc., 1986. The site is identified
as part of sub -basin 216 that flows into gutter number 36 and
then 32, according to the SWMM computer model from the above
reference.
DESCRIPTION
'
This property, as it currently exists, is farmland with farm
buildings in the northeast corner (see Drainage Plan in Pocket).
Several concrete irrigation ditches lie within this site which
'
are used for farming on this site and also to transport water
through this property. The northerly ditch transports water from
west to east through this property while the other ditches are
used for on -site irrigation. Sequence for development of this
'
area must be sensitive to this, as to not cut off irrigation
water from any non -developed land. The slope of this farmland is
'
from northwest to southeast while the irrigation ditches flow
primarily north to south or west to east.
The development of this property. is intended for businesses,
'
health care, office and industry, in accordance with the Wild
Wood Master Plan,
' DESIGN CRITERIA
' Master basin criteria for this study comes from the previously
mentioned McClellands Basin Master Drainage Plan. The report
outlines the entire major basin, identifying historic flows as
well as proposed developed flows. The report suggests a dual
' release rate of 0.20 cfs/acre for a 10 year design storm and 0.50
cfs/acre for a 100 year design storm. It must be noted at this
time that the 100 year release rate of 0.50 cfs/acre compares
' with a 0.30 cfs/acre + historic 100 year storm based on the 100
year peak flow, at gutter 36, of 41 cfs, divided by the sub -basin
216 area of 135• acres. City staff has agreed to the master
' drainage recommendations, from this report, and therefore estab-
lished criteria for this area.
Other drainage criteria used for the development of 'this property
' is to originate from the City of Fort Collins Storm Drainage
Design Criteria and Construction Standards Manual.
' DESIGN PROCEDURE
During the time of this report, the northwest corner of this property,
' shown on the drainage plan as a proposed site, is currently under design.
All other lots and street right-of-way's are shown as approximate
locations. The individual lots are to have onsite detention, however, the
' streets are to be ultimately detained in a permanent detention pond, as
shown on the drainage plan. Any partial development of the streets must
provide temporary street detention until a permanent pond is constructed.
The flows, after being detained, are to ultimately be released to a
proposed channel at the southeast corner of this property. These flows
will then enter the County Road 9 roadside ditch as shown on the drainage
' plan. The flows in this ditch travel south to finally enter the McClel-
lands Basin drainageway as is done historically.
' The development of the northwest site within this property will not greatly
increase flows downstream from that of historic. The 0.2 cfs/acre
difference, however, between the 100 year developed release rate (0.5•
cfs/acre) and the 100 year historic release rate (0.3 cfs/acre) will become
' more noticeable as this property and other properties within McClellands
Basin become developed. For the above reason the City must be aware that
downstream regional drainage improvements will be of increasing need. The
' roadside ditch for the west half of County Road 9 is currently unable to
handle 0.5 cfs/acre or 0.3 cfs/acre due to the flatness to the slope and
the numerous driveways which block or dam up the flow paths. Due to the
' above problems design flows during a major storm could require the total
county right-of-way along with some front of lot property. Future improve-
ments to county road 9 will require it to be able to handle 26.74 cfs
(133.7 ac. x 0.2 cfs/ac.) during a 10 year storm and 66.85 cfs (133.7 ac. x
0.2 cfs/ac.) during a 100 year storm from the Wild Wood Farm Property.
SUMMARY
t 1. The 10 year storm maximum release rate is to be 0.2 cfs/acre.
2. The 100 year storm maximum release rate is to be 0.5 cfs/acre.
3. On -site lot detention is required but should be combined with other
' lots when possible.
4. Streets are to have a permanent detention pond for full buildout.
5. Temporary street detention is necessary until a permanent pond is
constructed.
6. The flows from this property will ultimately drain into the County
Road 9 roadside ditch and then into McClellands Basin drainageway.
D(V, �7� Future County Road 9 will need to be able to pass 10 year storm flows
of 26.74 cfs and 100 year storm flows of 66.85 cfs from the Wild Wood
Farm property. Additional flows may enter County Road 9 South of this,
0 property. \\p�UU1;111uu�ugp���
incerely, �•`°�o�QF'�j�gEC%lF,%�
RBD, Inc.
... c o
Brian Cole, P.E. Ted Borstad P.E.
' Project Engineer
Project Manager
' 2
REFERENCES
1. McClellands Basin Master Drainage Plan, By Greenhorn and
O'Mara Inc., June 20, 1986.
2. City of Fort Collins Storm Drainage Design Criteria and Con-
struction Standards by City of Fort Collins, May 1984.
3. Urban Storm Drainage Criteria Manual, Volume 2, Section 5,
By Wright -McLaughlin Engineers, Denver, Colorado, March
1969.
3
No Text
VICINITY MAP
, � f
II ..tl-
-�0 -. , II <9 9 a II 11 27 1 1.iI \ \ 1.
v
• 1N' !~ /� it ' it � �� I � 1• ', ���
1\ I'
it
0.
t
• - EAST ° HOR TOOTH — 1954 ROA I <9.!<Ij `l <8n
II
l i I \ i '•,\ \\�
nWane v . 2 I\
It Park ( O I —
I 0
I ^
Collindale
Golf. urse
-
.
t) -- - - - - — I •ll , • 1 I Trail Park I .I 1 • _ r "�j 1 1
�.? of ••• -_ li_- I
ems• �;� �- \ I HARMONY HA
I I'
• M ROADLm-77N.
` �
@I
WILD WOOD IF
I � 1
0
0
a'
- l ( .:4
/l Z }
0
1RM / L) --
i
.1
\ \ /.00
I\ .. �_.:•_�\- _ 1�,I _ _
_ I 1 �'MAIL +'CREE
_D'TCH Al
K
•nn / n•nn. an• <aQ • mntlot—01 oaoOq �• wevar gs.on vleQ
10 YEAR STORM
MASS DIAGRAM METHOD
for
DETENTION VOLUMES `
PROJECT: WILD WOOD FARM (TEMPORARY STREET DETENTION POND)
COMMENTS: 10 YEAR STORM
MAXIMUM ALLOWABLE RELEASE. (CFS) =
RATIONAL EQUATION: Q = CIA
C 0.9
TIME OF CON('-'ENTRATION = ?
0.14
.�
�
0.72
C::f�
TIME
CA
I
INFLOW
OUTFLOW
STORAGE
(min)
(in/hr)
(cu ft)
(cu ft)
(cu ft)
(ac ft)
5
0.648
5.65
1098.36
42
1056-36
0.024250
10
0.648
4.4
1710.72
84
1626.72
0. 7344
15
0.648
3.7
2157.84
126
2031.84
0.046644
20
0.648
3.25
2527.2
168
2359.2
0,054159
25
0.648
2.85
2770.2
210
2560.20.058774
30
0.648
2.6
3032.64
252
2780.64
0.063834
35
0.648
2.35
3197.88
294
2903.88
0.066663
40
0.648
2.2
3421.44
336
3085.44
0.070831
45
0.648
2
3499.2
378
3121.2
0.071652
50
0.648
1.85
3596.4
420
3176.4
0.072920
55
0.648
1.75
3742.2
462
3280.2
0.0753O3
60
0.648
1.63
3802.464
504
3298.464
0.075722
70
0.648
1.44
3919.104
588
3331.104
0.076471
80
0.648
1.3
4043.52
672
3371.52
0.077399
90
0.648
1.2
` 4199.O4
756
3443,04
0.079041
100
0.648
1.1
4276.8
840
3436.8
0.078898
110
0.648
1
4276.8
924
3352.8
0.076969
120
0.648
0.9
4199.04
100B
3191.04
0.073256
t5 ab
^?-bb vu�'
I,
1
10 YEAR STORM
MASS DIAGRAM
METHOD
f or
DETENTION
VOLUMES
PROJECT:
WILD WOOD
FARM PERMANENT
STREET
DETENTION FOND
COMMENTS:
I() YEAR
STORM
/
MAXIMUM ALLOWABLE
RELEASE (CFS)
=
2.65
'
RATIONAL.
EQUATION:
O = CIA
O.Zc(a
c2t
C =
(:).9
A(area) -
13.23
�COru SEeVA�vt
TIME OF CONCENTRATION
=
?
S-rP.ELT
AREA
TIME
CA
I
INFLOW
OUTFLOW
STORAGE
'
(min)
(in/hr)
(cu ft)
(cu ft)
(ctA ft)
(ac ft)
S
11.907
5.65
20182.,36
795
19387.36
0.445072
10
11.907
4.4
31434.48
1590
29844.48
0.685134
15
11.907
3.7
3965o.31
2395
37265. 31
0.855493
20
11.907
3.25
4647-7.3
.3180
43257.3
0.993050
25
11.907
2.85
50902.42
3975
46927.42
1.077305
30
11.907
2.6
55724.76
4770
50954.76
1.169760
'• 5
11.907
2.35
59761.04
5565
5:3,196.04
1 . 221213-,
40
11.907
2.`)
62868.96
6360
56508.96
1.297_'67
'
11.90745 1.907
`'
64297.8
7155
57142.8
1.31.1818
50
11.907
1.85
66083. 85
7950
58133.83
1.334569
55
11.907
1.75
68762„92
8745
60Ci1.7.92
1.377821
'
60
11.907
1.63
69870. '27
9540
60330.27
1.384992
7i.1
11 . 907
1.44
7201.3„ 53
111:;0
60203.53
1.397693
80
1 1 . 90'7
1.3
74299. 68
12720
61.5 79. 68
1.413674
90
11.9o7
1.2
771. 5'7 ,, :=:6
1. 4:51 i i
6284.7.: ;6
1.442776
1'.. i)
11.907
1.1
78586.2
1590i i
62686.2
1.439077
11.0
11.907
1
78586.2
1.7490
61096.2
1.402575
120
11.9o7
0.9. 9
77157. 36
19090
58077. 36
1 . _ � 272
S�z4/as
'
3'c 2>.c-
wc.
)t6D
"22(,-ooS
.1
t
A3
- - �� '������ ��N�
m�� YEAR ��N�w�mmn�m
N� MASS DIAGRAM METHOD
m� for
DETENTION VOLUMES
m� PROJECT: WILD WOOD FARM (PROPOSED SITE)
COMMENTS:
10 YEAR
STORM
MAXIMUM ALLOWABLE
RELEASE (CFS)
2.33
N�
RATIONAL
EQUATION:
Q = CIA
C =
0.43
A(area) =
11.52
,--,I�����`^�`~��
c3c�
^E�.�e-�N-cuvr
U�
TIME OF CONCENTRATION =
?
TIME
CA
I
INFLOW
OUTFLOW
STORAGE
-------------------------------------------------------------�������������
(nin>
(in/hr)
(cu ft)
(cu ft)
(cu ft)
(ac ft)
5
4.9536
5.65
8396-352
699
7697.352
0.176706
Q�
10
.
4.9336
.
4 4
.
13077 50
1398
.
11679 50
0 268124
.
~�
15
4.9536
3,7
16495.48
2097
14398.48
0.330543
20
4.9536
3.25
19319.04
2796
16523.04
0.379316
H�
N�
25
4.9536
2.85
21176.64
3495
17681.64
0.405914
30.
4.9536
2.6
23182.84
4194
18988.B4
0.435923
35
4.9536
2.35
24446.01
4893
19553.01
0.448875
40
4.9536
2.226155.00
5592
20563.00
0.472061
0�
45
4.9536
2
26749.44
6291
20458.44
0.469661
50
4.9536
1.85
27492.48
6990
20502,48
0.470672
N�
55
60
4.9536
4.9536
1.75
1.6329067.72
28607.04
7689
838820679.720.474741
20918.04
0.480212
�
70
4.9536
1.44
29959,37
9786
20173.37
0.463116
80
4.9536
1.3
30910.46
11184
19726.46
0.452857
90
4.9536
1.2
32099.32
1258219517.32
0.448056
N�
100
4.9536
1.1
32693.76
13980
18713.76
0. 4729608
110
4.9536
1
32693.76
15378
17315.76
0.397515
120
4.9536
0.9
32099.32
16776
15323.32
0.351775
0�
8,`t sl
L^,[cZ>,Dv'a c,
�
100 YEAR
STORM
MASS DIAGRAM
METHOD
for
DETENTION V(:)LUMES
PROJECT:
WILD WOOD FARM (TEMPORARY
STREET DETENTION
FOND)
COMMENTS:
100 YEAR STORM
MAXIMUM ALLOWABLE RELEASE (CFS)
=
0.36
�o•S
RATIONAL
EQUATION: Q -
CIA
�{'IACRE
C =
1.
A(area)
_ 0.72
SHEET A,Zl
'TIME OF rr_LNe.E::NTRATIaN
== ��
TIME
CA
I
INFLOW
OUTFLOW
STORAGE
(min)
(in/hr)
(cu •ft)
(cut ft)
(cu ft)
(ac. ft)
5
0.72
9
194.4
J.E)8
1036
0„ 0421.48
10
i!.72
7.3
3,15:_T.6
21.6
2937.6
O.ii674._,8
1.5
0.72
6
3888
324
3564
D. i?81.818
20
0.72
5.2
4492.8
432
4i!6,:!.8
0.093223
25
0.72
4.6
4960
540
4428
0.101652
.30
o. 72
4.15
53,78. 4
640
4730.4 4
0.106595
35
0.72
3.8
5745.6
7`;6
4989.6
0. 1.14545
40
0.72
3.5
6048
864
5184
0.119008
45
0. 72
3.25
6318
972
5 ":46
0. 12.;'727
50
() . 72
3 _
6480
1 i i80
5400
0.123966
55
0.72
2.8
6652.8
1188
5464.8
0.125454--*
60
0.72
2.6
6739.2
1296
5443.2
0.124958
70
0.72
2.:
6955.2
1512
5443.2
0.124958
8C i
0. 7:'
2.05
70e4. 8
1720
5356.8
0.122975
90
0.72
1.65
'7192.8
1944
524.8.8
0.120495
S ClO
0. 72
1.7
7.344
2160
51.84
0. 119008
1 IQ
t .. '72
1 .55
73r 65. 6
2376
4989.6
0.114545
1`2!0
0.72
1.45
7516.8
2592
4924.9
0.113057
s /2 s/Sa
(2Q..-c)u'sr,
N
A5
I
100 YEAR STORM
MAsg DIAGRAM METHOD
fr . .
DETENTION VOLUMES
PROJECT: WILD WOOD FARM PERMANENT STREET DETENTION POND
COMMENTS.
100 YEAR
STORM
.
MAXIMUM ALLOWABLE
RELEASE (CFS)
6.62
.
RATIONAL EQUATION:
Q = CIA
§
c
!
Acareaa
= i3.23
- TIME! of CONCENTRATION
=
m
TIME
rmin;
CA
I
(i
INFLOW
(cu
OUTFLOW
w u It)
STORAGE
<ce ft> (ac ft)
hr)
+t)
s
1.3.23
9
35721
1906
33735
0.774449
10
l3.23
7.3
57947.4
3972
53975.4
1.239104
15
l3.23
6
71442
5953
65484
1.503305
20
13.23
5.2
92555.2
7944
74611.2
1.712837
25
l3.23
4.6
91287
99.
81357
1.867699
;n
l3.2J
4.1.5
98e2B.1
11916
86912.1
1.995227
35
1. 23
. 3.8
!0 75.4
13902
91673.4
2.104531
40
45
13.23
l3.23
25
111132
116 3.2
1588R
17874
9 55 2 44
98219.25
2"186501
2.2548o3
so
13.23
3
119070
19860
99210
2.27754e
ss
l3.23
2.8
122245.2
21846
l00399.2
2.' 248
60
l3.23
2.6
123832.8
23532
1 o0o.e
2.2957o2
70
1.2
33
3
127801.8
e04
99997.8
2.295633
Go
13.23
2. 05
1 183.2
31776
984 .2
2.259118
90
13.23
1.85
132167.7
35748
96419.7
2.213491
100
13.23
1.7
134946
39720
95226
2.1960ee
110
13.2=
1.55
lass .9
43692
91.650.9
2.1o4ol5j
120
1.3.23
1.45
138121.2
47664
90457.2
2.076611
.�
#z26-woe
�
.
\
A■
100 YEAR STORM
' MASS DIAGRAM METHOD
f or
' DETENTION VOLUMES
PROJECT: WILD WOOD FARM (PROPOSED SITE)
'
COMMENTS:
100 YEAR
STORM
MAXIMUM ALLOWABLE
RELEASE (CFS)
RATIONAL
EQUATION:
G == C I A
�I
C =
0.54
V7
A(area) =
11.52
T I ME Of-- CONCENTRAT"
I ON =
?
TIME
CA
I
INFLOW OUTFLOW
STORAGE
(min)
(in/hr)
(c)_) ft)
(cu ft)
(c..LA ft)
(ac ft)
------------__-
5
_---__.___
`,. 2208
91.6796.
1.6
1.746
150501.6
C).7�45504
'
1()
6.22()B
7.3
27247. 10
3492
23755. 10
0.545342
15
6. ^.x.'r)8
6
,.T,59.�?. ;:�?
,._. _,d
'•_F3"=.J4..'S.t
0.650925
2r)
6.2208 )8
5.2
38817. 79
6984
1833. 79
0. 73090:',
25
6. 2:208
4.6
42923. t.52
8730
3419 5. ?
0.784975
'
0
6. 2208
4. 1.5
46469.:"-7
1(-..)4'76
3599:3. 37
0, E326294
35
6. 2208
._ . 8
49641.98
1.2222
17A• 19. 98
0. 859044
'
40
A 5
6.22'?08
6.2200
:3..;`5 5
2
52254. 7'2
t` 4587. 5
13968
1 571. 4
':8286. 72
'; �8873. 52
0.978942
0.892413
50
6.2208
55987.2
17460
39527.2
0.884462
55
6. 2208
2.8
57480. V?
19206
_8274. 19
0.879654
'
60
6. 2208
2.6
58226. 68
2o952
37'274.. 68
0.955709
70
6. ?:'i �8
2. ,:.
60092.92
24444
35648. 92
0. 818386
B0
6.2208
2.05
61'212.67
27936
1.3.276.67
0.76:3927
9C)
6.2209
1.85
62145. 79
' 14 ?8
'•:0717. 79
0.705183
'
100
6.2208
1.7
6"35452. 16
34920
2e532.16
0. . 655008
110
6.2208
1.55
63638. 78
38412
25226.78
0.579127
' 120 6.2208 1.45 64945.15 41904 2•_,041.15 0.528952
' S/,e s/Ss
aJ c a,.0 . �Qeo )ac.
' f'226-c0°i
AT