HomeMy WebLinkAboutDrainage Reports - 05/13/2005t.",AWF�'►TY OF Final A W.
d ep�c�
17 IFORr COLUNS U-MITM
u
' Final Drainage & Erosion
_ Control Report
� East Vine Streets -Lot 4B
1 De -Icing Facility
� Ft. Collins, Colorado
II
II
u
11
II
I' September 2001
t � SEAR•BROWN
11
N �
SEAR• BROWN
October 26, 2001
Mr. Basil Hamdan
City of Ft. Collins
Stormwater Utility Department
700 Wood Street
Ft. Collins, Colorado 80521
ARCHITECTURE 209South Meldrum
ENGINEERING Fort Collins, CO 80521
PLANNING 970.482.5922 phone
CONSTRUCTION 970.482.6368 fax
www.searbrownxom
RE: Final Drainage & Erosion Control for the East Vine Streets Lot 4B De -Icing
Facility, Ft. Collins, Colorado
Dear Basil:
We are pleased to submit for your review and approval this Drainage and Erosion
Control Report for the East Vine Street Lot 4B De -Icing Facility. All computations
within this report have been completed in accordance with the City of Ft. Collins
Storm Drainage Design Criteria Manual.
We appreciate your time and consideration in reviewing this submittal. Feel free to
call if you have questions regarding the analysis performed or findings of this study.
Respectfully,
The Sear -Brown Group
Prepared by:
Stanley E. Dunn, P.E.
Project Engineer
cc: File 183-049
Vaught -Fry
I, Stanley E. Dunn, a registered professional engineer in the State of Colorado, hereby
certify that the information presented in this report was prepared by me or was
prepared under my direct supervision for the Owner(s) thereof.
Stanley E. Dunn, Colorado P.E.
0
1
I
i
.1
Table
of Contents
'
Tableof Contents.........................................................................................i
Section 1
'
General Location and Description................................................................3
1.1 Location.............................................................................................3
1.2 General Project & Property Description.............................................3
1.3 Site Soils Information.........................................................................6
'
1.4 Groundwater......................................................................................6
'
Section 2
Drainage Design Criteria..............................................................................7
2.1 Regulations........................................................................................7
2.2 Hydrologic Design Criteria.................................................................7
'
2.3 Hydraulic Design Criteria...................................................................7
2.4 On -Site Detention..............................................................................7
'
2.5 Variances From Criteria.....................................................................7
Section 3
'
Drainage Basins & Proposed Design...........................................................8
3.1 Major Basin Description.....................................................................8
3.2 Existing Sub -basin Description..........................................................8
3.1 Proposed Sub -basin Descrption & Design.........................................8
Section 4
'
Water Quality & Erosion Control...................................................................8
4.1 Water Quality.....................................................................................8
4.2 Erosion Control..................................................................................8
Section 5
Conclusions..................................................................................................11
'
5.1 Compliance with Standards...............................................................11
5.2 Site Development..............................................................................11
5.3 Drainage Concept ........................... :..................................................
11
'
5.4 Stormwater Quality Concept..............................................................11
5.5 Erosion Control Concept....................................................................11
'
References...................................................................................................12
A:Tinal Drainage Report.doc
WSE
]
'
A R• BROWN
I
I
i
1
1
I
I
I
A:%Final Drainage Report.doc
Table of Contents
Appendices
VicinityMap......................................................................................Al
Hydrology.........................................................................................A2
Inlet & Storm Drain System Design..................................................A3
Water Quality & Stormwater Detention.............................................A4
ErosionControl.................................................................................A5
Charts, Tables & Figures..................................................................A6
ff---S�EAR-BROW�N
e
ii
1
[1
Section 1
General Location and Description
1.1 Location
' The Project is located on Lot 4B of the East Vine Streets Facility, immediately south
of East Vine Street, and approximately 650 east of Linden Drive in Ft. Collins. The
property is situated between Lot 1 of the City's existing primary Streets Facility
offices and the future Colorado Department of Transportation (CDOT) Region 4
Maintenance Facility on Lot 4A (currently under construction).
The site location can also be described as situated in the Northeast 1/4 of Section 12,
Township 7 North, Range 69 West of the 6th P.M., City of Loveland, Larimer
County, Colorado.
1.2 General Project & Site Description
' Proposed Project improvements include overlot grading of the Lot 4B that will permit
construction of the future City De -Icing Facility. The facility will include a dome
structure to house and supply a variety of non -hazardous materials associated with
1 snow removal. The facility will also include structures appurtenant to operations of
the De -Icing materials dome structure (i.e. ramps, blending plant, break room, etc.).
City and regional snow removal vehicles will have access to the Site via a private
street off of Linden Drive.
The subject property of Lot 4B contains approximately 3.16 acres, and is currently
Iundeveloped. Existing topography generally slopes to the north and south from the
center of the Site at approximately 0.4 percent. Vegetation over existing Lot 4B is
representative of native grasses, and no trees or major bushes are present on Site.
' The Project consists of construction of a De -Icing facility that will serve the City of
Ft. Collins and external clients under precipitation events that occur during periods of
freezing temperatures, and where snow removal is required from local and regional
1 roadways.
Inspection of local floodplain maps (FEMA FIRM & Dry Creek Hydrologic Report)
and discussions with City Staff (M. Hilmes, July 2001) indicate that the Site is
located outside of the Dry Creek and Cache La Poudre floodplain limits, and no
1 wetlands have been identified. Drainage improvements will include overlot grading,
curb & gutter, drainage pans, and storm inlets.
' AAFinal Drainage Repomdoc 5- 5
SEAR•BROWN
I
I
1
1
11
I
I
1
0
n
' AAFinal Drainage Repomdm
1.3 Site Soils Information
Review of the SCS Soils Report for Larimer County, indicates that the natural soil
composition for Lot 4B is indexed as Caruso Clay, consisting primarily of clay -loam
to a depth of 25 feet below natural grade. More recently however, soil material has
been stockpiled and graded over the Site as part of City operations. No significant
erosion or sediment transport has been observed as a result of the recent spoil
stockpiling operations.
1.4 Groundwater
The East Vine Street Facility P.U.D. soils report (April 1991) indicates that
groundwater in the vicinity of Lot 4B lies between 5.5 and 7.0 feet below existing
grade. Based on proposed improvements, groundwater is not anticipated to be a
concern. However, in the event that groundwater is encountered during construction,
a Colorado Department of Health Construction Dewatering Permit will be required.
SEAR• BROWN
0
1
I
I
1
I
1
I
I
I
I
I
I
;'
1 A Final Drainage Report.doc
Section 2
Drainage Design Criteria
2.1 Regulations
The Project is located within the City of Ft. Collins, and design of On -Site Drainage
systems associated with the development of Lot 4B are in accordance with the Ctiy's
Storm Drainage Design Criteria Manual (1997).
2.2 Hydrologic Design Criteria
Based on the size of the Site, and in accordance with previous studies for the Project
area, the Rational Method is used to estimate peak surface runoff. Under City
criteria, the 2-year and 100-year storm events serve as the basis for design of on -site
drainage conveyance facilities. The analysis contained in this report incorporates the
City's updated rainfall.
2.3 Hydraulic Design Criteria
Hydraulic computations within this report have been prepared in accordance with the
City's Storm Drainage Criteria Manual. Estimates for peak runoff are determined
based on the City's equation for estimating time of concentration. Area inlets,
concrete pans and related storm sewers are designed based on City criteria.
2.4 On -Site Detention
The subject property is located within the Dry Creek Basin, and as such no detention
is required for this Site (Lot 4B). However, water quality mitigation is provided, and
Lot 4B runoff will be attenuated to historic rates through detention located further
downstream, and on the east side of the primary Streets Facility offices (Sear -Brown,
August 1999) along with additional drainage received from other properties tributary
to these ponds. Detention facilities used under this plan include Detention Ponds A
and B, with both including a water quality component immediately upstream of each
pond.
2.5 Variances from Criteria
No variances are requested or sought for this proposed Project.
/ SEAR•BROWN
7
11
Section 3
Drainage Basins & Proposed Design
3.1 Major Basin Description
IThe subject property lies within the Dry Creek Basin. However, no major
drainageway exists on the Site. The Project is not located within the 100-year
floodplain of either Dry Creek or the Cache La Poudre (Lidstone & Anderson, 1997,
FIRM Panel No. 080102-0002B, February 1984).
3.2 Existing Sub -basin Description
Currently, the subject property is vegetated with low growth, native cover. Generally,
drainage is split equally over the Site to the north and south, resulting in on -site two
sub -basin for Lot 4B (Sub -Basins NX-1 & NX-2).
Sub -basin NX-1 generally occupies the north half of the Lot 4B, and drains north-
northeast at approximately 0.4 percent to an existing swale along the north property
line. The swale conveys this sub -basin's and other tributary areas' drainage to Water
Quality Pond B, and subsequently to Detention Pond B (Sear -Brown, August 1999).
' Sub -basin NX-2 generally occupies the south half of the Site, and drains south-
southeast at approximately 0.4 percent to an existing swale along the south property
line. The swale conveys this sub -basin's and other tributary areas' drainage to an
existing area inlet tied to a 30-inch storm sewer line that conveys drainage to Water
Quality Pond B. Water Quality Pond B subsequently routes drainage to Detention
Pond B (Sear -Brown, August 1999).
Off -site drainage has historically been conveyed from Lot 4A through the northwest
and southwest quadrant of Lot 4B. However, with current development of Lot 4A for
' the CDOT Maintenance Facility, off -site drainage will be prevented from entering
Lot 4B via a 6-foot concrete pan currently being constructed along the west property
boundary of Lot 4B that intercept and convey Lot 4A drainage to an area inlet at the
1 southwest corner of Lot 4B.
3.3 Proposed Sub -basin Description & Design
Based on proposed overlot grading and construction of on -site and off -site facilities,
there will be three (3) on -site sub -basins. These are identified on the proposed
drainage plan included with this report as 4B-1, 4B-2 and 4B-3. Grading of Lot 4A
(CDOT Site immediately to the west) and installation of a 6-foot wide drainage pan
AAFinal Drainage Rcporubc 6
ff___S E A R - B R �OWN
' (between Lot 4A and 4B) will mitigate off -site storm runoff from entering the City's
De -Icing facility property.
' Sub -basin 4B-1 (1.16 acres) will drain to the north-northeast via overland flow at
approximately 2.0 percent, to the existing swale along the north property line. This
sub -basin will include a portion of the De -Icing facility storage dome, ramp structure,
asphalt pavement and landscaped areas. Drainage contained within the 1000-Gallon
Tank containment area will be released via manual spigots that will be opertaed
' during and after storm events. Sub -basin 4B-1 storm runoff will then drain east via
the north property swale, where it will be attenuated through existing Water Quality
Pond B, then released via Detention Pond B (reference Sear -Brown, August 1999).
Drainage will ultimately be released to the Cache La Poudre River.
' Sub -basin 4B-2 (1.55 acres) will generally drain to the south-southeast via overland
flow at approximately 2.0 percent, to a proposed concrete pan along the south
property line and area inlet are the southeast comer of the property. An 8-foot
' concrete pan along the east property line will facilitate drainage to the proposed area
inlet at the southeast corner of the Site. This sub -basin will include a portion of the
De -Icing facility storage dome, ramp structure, blending plant, break room, private
drive and asphalt pavement area. Sub -basin 4B-2 storm runoff will drain east via a
24-inch Class M. reinforced concrete pipe (RCP) underlying the 8-foot concrete pan.
This storm pipe was.recently installed and tied to an existing 24-inch stub/area inlet
structure located on the south side of Lot 1 of the City's Streets main complex as part
of development associated with the CDOT project immediately west of the subject
property. Sub -basin 4B-2 runoff will ultimately be routed through existing Water
Quality Pond A, and released through Detention Pond A (reference Sear -Brown,
August 1999). Drainage will ultimately be released to the Cache La Poudre River.
Sub -basin 4B-3 (0.44 acres) will generally drain to the south via overland flow at
approximately 2.0 percent, to a future 8-foot concrete pan along the west property
1 line (currently under construction as part of Lot 4A improvements). Drainage
contained within the 1000-Gallon Tank containment area will be released via manual
spigots that will be opertaed during and after storm events. Drainage from this sub -
basin will enter an area inlet at the southwest corner of the property. This sub -basin
will include a portion of the break room and pavement area. Sub -basin 4B-3 storm
runoff will drain east via an 24-inch Class III, RCP underlying the 8-foot concrete
' pan (recently installed with development of Lot 4A). This storm pipe was recently
installed and tied to an existing 24-inch stub/area inlet structure located on the south
side of Lot 1 of the City's Streets main complex as part of development associated
' with the CDOT project immediately west of the subject property. Sub -basin 4B-3
runoff will ultimately be routed through existing Water Quality Pond A, and released
through Detention Pond A (reference Sear -Brown, August 1999). Drainage will
ultimately be released to the Cache La Poudre River.
AAFinal Drainage Reportdon 7
9 SEAR• BROWN
1
I
Section 4
Water Quality & Erosion Control
4.1 Water Quality
Water quality for Lot 4B will be provided via existing Water Quality Ponds A and B,
located on the east side of Lot 1. Lot 4B surface runoff will be discharged to these
' ponds in accordance with the Phase One Final Report (SBG, August 1993). In
accordance with that study and the existing ponds, first flush of debris, oils and
highway snow removal chemicals. The water quality ponds will have a 40-hour
release period into respective detention ponds effectively providing filtration via
natural vegetative and absorbtion factors.
1 4.2 Erosion Control
This development lies within the Moderate Rainfall Erodibility and Moderate Wind
Erodibility Zones per City meteorologic zone map. The Erosion Control Performance
(PS) and Effectiveness (EFF) during construction were computed to be 80 percent
and 95 percent, respectively. Post -Construction PS and EFF were estimated to be 94
percent and 96 percent, respectively.
Post overlot grading conditions will require that all disturbed areas not in a roadway,
paved area or greenbelt will have temporary vegetation seed applied. Applied seed
will be covered with hay or straw mulch at a rate of 2 tone/acre, and mulch will be
adequately tacked or cripped into the soil.
' Areas to be paved must have a 1-inch layer of gravel mulch, applied at a rate of 135
tons/acre immediately after overlot grading is complete. Pavement should be applied
I as soon as possible and after Site utilities have been installed. Disturbed areas
(including the south parking area) will not to be built on within one year must have
permanent seed applied at 2 tons/acre and adequately mixed with topsoil material.
1 All construction activities must comply with State of Colorado permitting process for
Stormwater Discharge Associated with Construction Activity. If at any time during
construction, groundwater is encountered, a Colorado Department of Health NPDES
permit will be required, and must be secured by the Contractor.
A:%Final Drainage Reportdoc 10
SEAR•BROWN
i
Section 5
Conclusions
5.1 Compliance with Standards
Computations included in this Final Drainage & Erosion Control Report are in
compliance with the City of Ft. Collins Erosion Control Manual for Construction
Sites and Storm Drainage Criteria Manual. Surface runoff discharged from Lot 4B is
in conformance with previous studies. The Site is not situated within any floodplains
or drainageway that might impact on -site or off -site facilities, or result in damages as
a result of stormwater inundation.
' 5.2 Site Development
The Site will be operated and maintained as a facility that serves highway de-icing
operations. The City will maintain non -hazardous materials used for those
operations. A dome storage facility will occupy. the center of the Site. A breakroom
will be located in the southwest part of the Site.
5.3 Drainage Concept
' The proposed drainage plan is in conformance with City criteria, and will adequately
convey storm runoff from Lot 4B to existing outfall points (Water Quality and
' Detention Ponds A & B). Discharge rates to these outfall points will be in
conformance with previous studies. Both 2-Year and 100-year runoff will be
conveyed via open -channel and storm sewer systems. No adverse impact to existing
' properties or connecting storm conveyance systems is anticipated.
5.4 Stormwater Quality Concept
Water quality for Lot 4B will be provided via existing Water Quality Ponds A and B,
located east of the subject property (Lot 1). Stonnwater pollutants will be filtered
' prior to discharge into respective detention ponds, also located east of the Site (Lot 1).
' 5.5 Erosion Control Concept
Proposed erosion control measures will mitigate erosion due to wind or rainfall.
Erosion control measures will be installed and maintained from start of construction
to final landscaping. Performance and Effective Standards meet City requirements.
i
AAFinal Drainage ReporLdm 11
SEAR•BROWN
i
11
LI
i
IA:Winal Drainage Report.doc
References
1. Final Drainage & Erosion Control Study, East Vine Streets Facility P.U.D.,
Major Amended Final, Phase Two Final, Ft. Collins, Colorado, Sear -Brown,
August 1999.
2. Final Report, Hydrologic Model Update for the Lower Dry Creek Basin
Master Drainage Plan, Lidstone & Anderson, September 10, 1997.
3. Flood Insurance Rate Map Panel No. 080102-0002B, FEMA, February 1984.
4. Final Drainage & Erosion Control Study for the East Vine Streets Facility
P.U.D., Phase One Final, RBD, March 1993.
5. Storm Drainage Design Criteria & Construction Standards, City of Ft. Collins,
May 2984 (Rev. 1/97).
6. Erosion Control Reference Manual for Construction Sites, City of Ft. Collins,
January 1991.
SEAR• BROWN
12
I
I
i
I
I
L
I
i
I
I
I
1-1
I
I
I
I
'rI
I
VICINITY MAP
I
I,
3nN2AV ;,Vk2l
Z:
i2:
wi
CL
110 ,D: nN3
[1
1
1
1
i
1
i
1
1
1
1
1
11
1
11
1
i
1
HYDROLOGY
1
I
7
Existing Conditions
11
11
7
i
- 9
THE
SEAR -BROWN
GROUP
'CLIENT: Apr- Project No: 68E oN"
Project: -3 Checked By: -
By: ar Date: Sheet: _ Of: =J
I
1
11
SUMMARY OF HYROLOGIC PARAMETERS
Existing Conditions
Basin
ID
Area
(acres)
C
2yr
C
100yr
NX-1
1.57
0.25
1.00
NX-2
1.59
0.29
1.00
PEAK DISCHARGE SUMMARY TABLE
Existing Conditions
Basin
ID
Area
(acres)
Q2YR
(cfs)
0100YR
(cfs)
NX-1
1.57
0.8
3.9
NX-2
1.59
1.0
4.6
Sum
3.16
1
1
1
1
?�
&&�b55
ww
-ww
bSS�676
EE
E E
E E
EE g
y$
E
e g
J
J J
J J
J
m m
J
J J
J J
J
E
E E
J
Ktl
N
N
E
tl
t
6111
1
d u
F
�'�
E^
c
N�i$nn
FuR
o
F
nNm
�jE�
San
��588$
66
SRASmB
eo
e
�
J
Joe
0
w
8
R
AAAASS
O—K
C
;
8
M
UM
o.
O
O O
O O
O
yQHj
J�
O
iSSiii
o �O
ry
G
o
OO O
gg
tl
O G
AA
b
O
pp
ti
OO OO
g
2S
O
O
yy
3
G
0
O
W
F
b
J
a
�s.
S�88R#S�RRrRA
G
G O
O O
O C
C C
O G
O O
:��a�xi
O
OO OO
O G
G
8$818128
nFE
$88S
i•�_n
o o
d
a
c
E
b
95
` u
eFi
F
c
ddb��Saad����
o
etii��g
=
8
5Sq
F�
a�
UU
K
R
G
�
b
b b
S ffi
ffi
S
G G
u S
b
gCg��
W
W W
W W
gg,ggg
J
J J
J J
J
0+
J J
J J
J
'a
F
f F
's'aeLL���a
F F
E
F LL
E
LL
J�
F
F F
F F
10-
N
N^
o N
N -OF
n
0
tl N
o N
m
f
'yjS
Sn
SS�S
�868
88$S6$
y4�
����
mRRB�ffi
8
8�
�S�goS
-�a
0
r
'E^
o
s
�gm
S
R
AAAAeB
g�=1a
ox.
y
6
6
0 0
0
im
ryas
u
p Em
m
b 0
8
g 8
8
o
W
y
O
O OO
OO
m
O
C
O
6
F
f
e.
8.8
3868;
Fin
8,
8888,
8 nR
8888
a
'aF
S=m8
�_
F
oa0000_
oo_
omec�m
m-6
8ga"aNa
miti
zp
a�
�
�
�
z
8
63VRp 9
��8 a
�igi
���
'�
'
��I
NlII
i
�
��
��
,I��
��
��
s
FJ
!
LL N
C
5
�Lm
CVS
�
6 C y)
N `
<
y
O
W H1N
N(7nON
m 0
r0�
W
W N
r
N NfOmr
N t7
N
V
O�^
000000�('lO
i
N
1
f
LL
OOL�
Z
7
K
pp
rNcl
�p
In �Y
�^
OOOOOO�CION
�110
NNY�
��
d�
'�
y
���N
W HIN�A
W
1�1
IDmrnN
V 1
20
O
oom
O N
f O n
fY
W
NMQOOm
m O
O O
N N
W W
N
r00(O
O O
N
NN
N
c =
ai
oia
ri a
ni mmai
aiv
ai ei
ui
of of
ai 0
vi
00r0
Oo
�o
W
n
o=N
IT
W
N cm
000666.0
00o00
6C5�:c�:
.d cm
oo0i.�01^�noo"oo
`0ooa0D
1O
E
1N
YIN�NMr�IN
ul �
YI Yf
�ul
Y1
f0 ��
g
t � n
F E
_T$
6N
O
d
J
O
2
j
O n
00 F N
L
C C <
J V
E�'
NNN�N�rNNNNNN
aj
6 N(O��
C
N
tS1N
t7vNm
OOOOQ<Q¢QZZ
.=====c
0
TT
m
N
x
a
NNfA
N
aaaaaaaaaa
0 0
N N
0 0
f%1 N(�fnNNNf/7
N N
0 0
N N
0 0
N N
0
N N
oaaaaa
0
N
0 0
N N
0 0
N N
0
N
E
>
0
> >
0 0
> >
0 0
0 >
0 0
> >
0 0
0 0
0 0
0
0
0 0
0 0
0 >
0 0
>
0
vm
u�vvm�i
�iv
0
�mm
�j
a`a
a`aaa
a`$aa&
ea
E
E E
E E
E E
E E
E E
I
E
E E
E
E
eeeeeeeeeeedo
eeee
e
LL
LL LL
LL LL
LL LL
LL LL
LL LL
J J
1
1LL
LL LL
LL LL
LL
I
1
1
n
Proposed Conditions
d
1
e— .0 'ls
THE
SEAR -BROWN
GROUP
Project53�cnr—,- 02rY Project No.o`�9
By: Checked:
Date: Sheet Sheet of
I
.1
I
1
I
I
SUMMARY OF HYROLOGIC PARAMETERS
Proposed Development
Basin
ID
Area
(acres)
C
2yr
C
100yr
4B-1
1.16
0.85
1.00
4B-2
1.55
0.95
1.00
4B-3
0.44
0.95
1.00
PEAK DISCHARGE SUMMARY TABLE
Proposed Development
Basin
ID
Area
(acres)
Q2YR
(cfs)
Q100YR
(cfs)
4B-1
1.16
2.6
9.8
4B-2
1.55
4.2
14.3
4B-3
0.44
1.2
4.2
Sum
3.15
a�-
aaaaaapmp��
sasses
w
w w
w
E
g
J
E E
gggggii���
JJJJ'Y
E E
E y
s y
`o S
mmm
.�.�
JJ'JJSJ'
E E
ggg
E
1
1 8
i
a E
E E
w
E E
'a
O m
E^
O
mn
O O
O b
O
aye
-
n
O
F
b
O
�J
f
E'
ryry
o"o..
onv�Nm
^
S
<
an
g
8'e28�m8
¢�
E�
cone$
w?5
Z LL
u�F
J
m
s
^
0
sRR0„2
'Al
Il
I IS
S
w
F�5
a
R
$$$
RRAAe
B.
ii'ge
o%e
8
8
S 8
8
R
53 R
53
5!
b�
E
CC
0
'E�
^
n'Rry
O e
ry
E m
«^
o
yy yy
S b
AA
b
S a
S
QQ
E
g
5
0
iiiiQ W
g
C
C G
G G
G
G
O
O
C
a
rr
8SR80.a88
Sle
8$.
88
s.
84
0.
c o
o e
6
6 d
o c
c
_
�y"
88.8888�
0000m
8833
S.
68
a
c
'F
�
b
� a.
� �
� lei
�ooe:a^
v
a
s
8
8.
bbb�daaaa�a�a
tit�tg
o
L
8
�q$a@����
gg
qaq@a@QaQQaQyaQ@aQmmmm�
m
E
9g99ee5
E E
E E
E y
t
E
E E
E E
E
J
_rssss
i
a
a
a a
FFFi=F
i D
E
8 E
LLLL
E E
E
E::m
E E
E E55E
FFF��='=
J
E'
M
0
0
0 o
e
0 N
m
D�.
E�
ry„wed
rv�i
� ri
ri
88
Sig
08
E^
c
d
c e
Z Y
J
r
_<
em
mesas
'E
w
gige
a
R
d d
b
I
did
..
X
q
Q
m
.+En
r8
yy$$pp
$$qq
yy
o
0 OG
O
O
00
F
��y
8
�gg u
o
6 d
0^
6 o
s
d o^
888
6
a 8m8�
T
r
o
a;m
162<k
a
�^i`ttiIP
1
v
;I.
1
i
1
1
1
1
1
1
1
1
1
1
1
I
II
If
I
I
I
I
IJ
1
' INLET & STORM DRAIN SYSTEM DESIGN
I
I
1
1
I
11]
I
I
I
I
THE
SEAR -BROWN
GROUP
C3/J���rv�
o—
w
r LIENT: /cProject No: L s- ovi-,*N
Project: Checked By:
�By:ti Date: e4tc ct Sheet: Of:
/ivy ieArf
Isa ra-® •u - /am-S� �.
u
Worksheet
Worksheet for Trapezoidal Channel
Project Description
Worksheet
North Swale
Flow Element
Trapezoidal Channe
Method
Manning's Formula
Solve For
Channel Depth
Input Data
Mannings Coefficient 0.030
Slope
0.005000 ft/ft
Left Side Slope
6.00 H : V
Right Side Slope
6.00 H : V
Bottom Width
4.00 ft
Discharge
9.77 cfs
Results
Depth
0.63 ft
Flow Area
5.0 ft'
Wetted Perimetei
11.72 ft
Top Width
11.61 ft
Critical Depth
0.45 ft
Critical Slope
0.019336 ft/ft
Velocity
1.97 f /s
Velocity Head
0.06 ft
Specific Energy
0.69 ft
Froude Number
0.53
Flow Type
Subcritical
-- Q r ov Fmowti. (.eT K
Project Engineer: Stanley Dunn
untitled.fm2 The Sear -Brown Group FlowMaster v6.1 [614k]
10/26/01 08:47:48 AM 0 Haestad Methods, Inc. 37 Brookside Road Waterbury, CT 06708 USA (203) 755-1666 Page 1 of 1
Worksheet
Worksheet for Trapezoidal Channel
Project Description
Worksheet
North Swale
Flow Element
Trapezoidal Channe
Method
Manning's Formula
Solve For
Discharge
Input Data
Mannings Coefficient
0.030
Slope
0.005000 ft/ft
Depth
2.50 ft
Left Side Slope
6.00 H : V
Right Side Slope
6.00 H : V
Bottom Width
4.00 ft--
Results
Discharge
206.23 cfs
Flow Area
47.5 ft'
Wetted Perimetei
34.41 ft
Top Width
34.00 ft
Critical Depth
2.06 ft
Critical Slope
0.012638 ft/ft
Velocity
4.34 ft/s
Velocity Head
0.29 ft
Specific Energy
2.79 ft
Froude Number
0.65
Flow Type
Subcritical
Project Engineer: Stanley Dunn
untitled.fm2 The Sear -Brown Group FlowMaster v6.1 [614k]
10/26/01 09:27:40 AM ®Haestad Methods, Inc. 37 Brookside Road Waterbury, CT 06708 USA (203) 755-1666 Page 1 of 1
THE
SEAR -BROWN
GROUP
G,A-?elV.
Project: �rxet�3 �ar Project No.-,Iff- `J 9
By: Checked:
Date: �/� y// Sheet I of Z
THE
SEAR -BROWN
GROUP
Project:Project No./83-oc�9
By: Checked:
Date: /�// Sheet Z of 2
0.8
0.7
P
w 0.6
f-
Iy
Z 0.5
w
> 0.4
O
a 0.3
W
O-
C7
? 0.2
O
Z
O
a 0.1
MAY 1984
EXAMPLE
0.0 3 4
O I 2
FLOW INTO INLET PER SO. FT. OF OPEN AREA (CFS/FT2)
Figure 5-3
CAPACITY OF GRATED INLET IN SUMP
(From: Wright -McLaughlin Engineers,1969)
5-11
DESIGN CRITERIA
1
1
1
1
1
Engineering Consultants - : '
CUENT VA(I6NT-Or FKYE JOBNO. M3
PROJECT C72CACCUVITION3 FOR
MADE OATS' I NECKED BY OATS SHUT ZZ OF,
�.. ;IJl
hl p v+
V.
' 0LZ 62,1- CL- V) m
.. -_•: �_ _:cam
vov
... ... _ _�.` en.—
AI
L ° o %4 N_ r
4`IQJ—.
11 ...u_
'_1 � r .. _
a
.. c � ,'��-� r c�.t� • �, '�� Lam.. ..... .
L•
-y0
d. /
LLI—
> > > .� . `1 . p
L
-
T . CE!
c,
7
ll� -
I,loll
SA
-
a
� Zj fir
�-•.T— -,TT T
I
7S
1
1
1
----------------------------------------------------------------------------
STORM SEWER SYSTEM DESIGN USING UDSEWER MODEL
Developed by Civil Eng. Dept, U. of Colorado at Denver
Metro Denver Cities/Counties & UDFCD Pool Fund Study
------------------------------------------------------------------------------
USER:RDB-Fort Collins -Colorado ...............................................
ON DATA 06-28-1999 AT TIME 15:15:37 VERSION=01-17-1997
*** PROJECT TITLE :Fort Collins Streets Facility - Storm Sewer
*** RETURN PERIOD OF FLOOD IS 2 YEARS - The 1993 phase of design used the 2-year event to size the storm
sewer. The same methodology is continued in this analysis of the
entire storm sewer system.
(Design flow hydrology not calculated using UDSEWER)
*** SUMMARY OF HYDRAULICS AT MANHOLES
-------------------------------------------------------------------------------
MANHOLE CNTRBTING RAINFALL RAINFALL .DESIGN GROUND WATER COMMENTS
ID NUMBER AREA * C DURATION INTENSITY PEAK FLOW ELEVATION ELEVATION
MINUTES INCH/HR CFS FEET FEET
-------------------------------------------------------------------------------
10.00 19.40 50.00 47.00 OK
20.00 19.00 50.50 48.08 OK
30.00 19.00 51.50 48.47 OK
40.00 17.90 52.15 49.50 OK
50.00 14.40 52.53 50.22 OK
60.00 12.90 52.50 50.55 OK
70.00 12.90 52.50 50.57 OK
80.00 8.46 54.00 50.84 OK - Q2 is less than 1993 report.
90.00 6.39 55.15 51.43 OK
95.00 1.45 50.54 51.44 NO
55.00 3.50 51.50 50.78 OK
56.00 3.50 51.50 50.94 OK
45.00 3.50 51.70 49.91 OK
46.00 3.50 51.70 50.08 OK
35.00 1.30 48.32 48.94 NO
36.00 1.30 48.32 48.95 NO
OK MEANS WATER ELEVATION IS LOWER THAN GROUND ELEVATION
*** SUMMARY OF SEWER HYDRAULICS
NOTE:
THE GIVEN
FLOW DEPTH -TO -SEWER SIZE RATIO= 1
------------------------------------------------------
SEWER
MAMHOLE
NUMBER
SEWER
REQUIRED
SUGGESTED
EXISTING _
ID NUMBER
UPSTREAM
DNSTREAM
SHAPE
DIA(RISE)
DIA(RISE)
DIA(RISE)
WIDTH
ID NO.
ID NO.
(IN) (FT)
(IN) (FT)
(IN) (FT)
(FT)
--------------------------------------------------------------------
1.00
20.00
10.00
ROUND
29.38
30.00
30.00
0.00
2.00
30.00
20.00
ROUND
29.38
30.00
30.00
0.00
3.00
35.00
30.00
ROUND
11.12
15.00
12.00
0.00
4.00
40.00
30.00
ROUND
28.73
30.00
30.00
0.00
5.00
45.00
40.00
ROUND
14.16
15.00
15.00
0.00
6.00
50.00
40.00
ROUND
26.48
27.00
30.00
0.00
7.00
55.00
50.00
ROUND
14.16.
15.00
15.00
0.00
8.00
60.00
50.00
ROUND
25.41
27.00
30.00
0.00
9.00
70.00
60.00
ROUND
25.41
27.00
30.00
0.00
10.00
80.00
70.00
ROUND
21.69
24.00
24.00
0.00
11.00
90.00
80.00
ROUND
19.53
21.00
24.00
0.00
12.00
95.00
90.00
ROUND
11.20
15.00
15.00
0.00
13.00
36.00
35.00
ROUND
11.12
15.00
12.00
0.00
14.00
46.00
45.00
ROUND
14.16
15.00
15.00
0.00
15.00
56.00
55.00
ROUND
14.16
15.00
15.00
0.00
DIMENSION UNITS FOR ROUND AND ARCH SEWER ARE IN INCHES
DIMENSION UNITS FOR BOX SEWER ARE IN FEET
REQUIRED DIAMETER WAS DETERMINED BY SEWER HYDRAULIC CAPACITY.
SUGGESTED DIAMETER WAS DETERMINED BY COMMERCIALLY AVAILABLE SIZE.
FOR A NEW SEWER, FLOW WAS ANALYZED BY THE SUGGESTED SEWER SIZE; OTHERWISE,
EXISITNG SIZE WAS USED
-76
I
I
1
1
1
L
[1
----------------------------------------------------------
SEWER DESIGN FLOW NORMAL NORAAL CRITIC CRITIC FULL FROUDE COMMENT
ID FLOW O FULL Q DEPTH VLCITY DEPTH VLCITY VLCITY NO.
NUMBER CFS CFS FEET FPS FEET FPS FPS
------------------------------------------------------------------------------
1.0 19.0 20.1 1.93 4.67 1.47 6.31 3.87 0.59 V-OK
2.0 19.0 20.1 1.93 4.67 1.47 6.31 3.87 0.59 V-OK
3.0 1.3 1.6 0.69 2.27 0.50 3.34 1.66 0.51 V-LOW
4.0 17.9 20.1 1.83 4.64 1.43 6.16 3.65 0.62 V-OK
5.0 3.5 4.1 0.89 3.75 0.75 4.53 2.85 0.73 V-OK
6.0 14.4 20.1 1.56 4.46 1.30 5.59 2.93 0.68 V-OK
7.0 3.5 4.1 0.89 3.75 0.75 4.53 2.85 0.73 V-OK
8.0 12.9 20.1 1.45 4.36 1.24 5.29 2.63 0.70 V-OK
9.0 12.9 20.1 1.45 4.36 1.24 5.29 2.63 0.70 V-OK
10.0 8.5 11.1 1.31 3.89 1.05 5.07 2.69 0.64 V-OK
11.0 6.4 11.1 1.09 3.66 0.90 4.65 2.03 0.69 V-OK
12.0 1.5 3.2 0.59 2.53 0.50 3.19 1.18 0.66 V-LOW
13.0 1.3 1.6 0.69 2.27 0.50 3.34 1.66 0.51 V-LOW
14.0 3.5 4.1 0.89 3.75 0.75 4.53 2.85 0.73 V-OK
15.0 3.5 4.1 0.89 3.75 0.75 4.53 2.85 0.73 V-OK
FROUDE NUMBER=O INDICATES THAT A PRESSURED FLOW OCCURS
------------------------------------------------------------
SEWER
SLOPE
INVERT ELEVATION
BURIED
DEPTH
COMMENTS
ID NUMBER
UPSTREAM DNSTREAM
UPSTREAM
DNSTREAM
(FT)
(FT)
(FT)
------------------------------
1.00
0.24
46.27
46.00
1.73
1.50
OK
2.00
0.24
46.57
46.30
2.43
1.70
OK
3.00
0.20
46.72
46.60
0.60
3.90
NO
4.00
0.24
47.42
46.60
2.23
2.40
OK
5.00
0.40
47.51
47.45
2.94
3.45
OK
6.00
0.24
48.41
47.45
1.62
2.20
OK
7.00
0.40
48.73
48.45
1.52
2.83
OK
8.00
0.24
48.84
48.45
1.16
1.58
OK
9.00
0.24
48.90
48.88
1.10
1.12
OK
10.00
0.24
49.40
48.95
2.60
1.55
OK
11.00
0.24
50.34
49.55
2.81
2.45
OK
12.00
0.24
50.54
50.49
-1.25
3.41
NO
13.00
0.20
46.72
46.72
0.60
0.60
NO
14.00
0.40
47.51
47.51
2.94
2.94
OK
15.00
0.40
48.73
48.73
1.52
1.52
OK
OK MEANS BURIED
DEPTH
IS GREATER
THAN REQUIRED SOIL COVER OF
1 FEET
*** SUMMARY OF HYDRAULIC GRADIENT LINE ALONG SEWERS
------------------------------------------------------------------------------
SEWER SEWER SURCHARGED CROWN ELEVATION WATER ELEVATION FLOW
ID NUMBER LENGTH LENGTH UPSTREAM DNSTREAM UPSTREAM DNSTREAM CONDITION
FEET
FEET
FEET
FEET
FEET
FEET
-----------------------------------------------------
1.00
112.00
0.00
48.77
48.50
48.08
47.00
SUBCR
2.00
114.00
0.00
49.07
48.80
48.47
48.08
SUBCR
3.00
60.00
60.00
47.72
47.60
48.94
48.47
PRSS'ED
4.00
340.00
0.00
49.92
49.10
49.50
48.47
SUBCR
5.00
15.00
15.00
48.76
48.70
49.91
49.50
PRSS'ED
6.00
400.00
0.00
50.91
49.95
50.22
49.50
SUBCR'
7.00
71.00
71.00
49.98
49.70
50.78
50.22
PRSS'ED
8.00
161.00
0.00
51.34
50.95
50.55
50.22
SUBCR
9.00
8.00
0.00
51.40
51.38
50.57
50.55
SUBCR
10.00
187.00
0.00
51.40
50.95
50.84
50.57
SUBCR
11.00
329.21
0.00
52.34
51.55
51.43
50.84
SUBCR
12.00
20.00
0.00
51.79
51.74
51.44
51.43
SUBCR
13.00
0.10
0.10
47.72
47.72
48.95
48.94
PRSS'ED
14.00
0.10
0.10
48.76
48.76
50.08
49.91
PRSS'ED
15.00
0.10
0.10
49.98
49.98
50.94
50.78
PRSS'ED
PRSS'ED=PRESSURED FLOW; JUMP=POSSIBLE HYDRAULIC JUMP; SUBCR=SUBCRITICAL FLOW
1
I�-
' *** SUMMARY OF ENERGY GRADIENT LINE ALONG SEWERS
UPST
MANHOLE
SEWER
JUNCTURE LOSSES
DOWNST
MANHOLE
'
SEWER MANHOLE
ENERGY
FRCTION
BEND
BEND LATERAL
LATERAL
MANHOLE
ENERGY
ID NO
ID NO.
ELEV FT
FT
K COEF
LOSS FT K
COEF LOSS FT
ID
FT
-------------------------------------------------------------------------------
1.0
20.00
48.45
1.45
1.00
0.00
0.00
0.00
10.00
47.00
'
2.0
30.00
48.84
0.30
0.38
0.09
0.00
0.00
20.00
48.45
3.0
35.00
48.98
0.08
1.33
0.06
0.00
0.00
30.00
48.84
4.0
40.00
49.83
0.75
0.25
0.05
0.25
0.18
30.00
48.84
5.0
45.00
50.04
0.04
1.33
0.17
0.00
0.00
40.00
49.83
6.0
50.00
50.53
0.49
0.25
0.03
0.25
0.17
40.00
49.83
7.0
55.00
50.90
0.21
1.33
0.17
0.00
0.00
50.00
50.53
8.0
60.00
50.80
0.14
0.25
0.03
0.25
0.11
50.00
50.53
9.0
70.00
50.80
0.00
0.05
0.01
0.00
0.00
60.00
50.80
10.0
80.00
51.03
0.23
0.05
0.01
0.00
0.00
70.00
50.80
11.0
90.00
51.64
0.61
0.05
0.00
0.00
0.00
80.00
51.03
12.0
95.00
51.48
0.00
0.05
0.00
0.00
0.00
90.00
51.64
13.0
36.00
48.99
0.00
0.25
0.01
0.00
0.00
35.00
48.98
14.0
46.00
50.21
0.00
1.33
0.17
0.00
0.00
45.00
50.04
15.0
56.00
51.07
0.00
1.33
0.17
0.00
0.00
55.00
50.90
BEND LOSS =BEND K* FLOWING FULL
VHEAD
IN SEWER.
LATERAL
LOSS= OUTFLOW FULL VHEAD-JCT
LOSS K*INFLOW
FULL
VHEAD
FRICTION LOSS=O MEANS
IT IS NEGLIGIBLE
OR POSSIBLE ERROR
DUE
TO JUMP.
I
FRICTION LOSS
INCLUDES SEWER INVERT DROP
AT MANHOLE
NOTICE:
VHEAD
DENOTES
THE VELOCITY HEAD OF FULL
FLOW CONDITION.
A MINIMUM JUCTION LOSS
OF 0.05
FT WOULD
BE INTRODUCED
UNLESS
LATERAL K=O.
FRICTION LOSS
WAS ESTIMATED BY
BACKWATER
CURVE COMPUTATIONS.
'
I
I
I
1
I
I
11
'1
I
1
I
WATER QUALITY & STORMWATER
DETENTION
(From Previous Studies)
I
I
li
I
11
1
2G-
Fort Collins Streets Facility
Composite Rational Method Runoff Coefficient for Detention Pond
Designer: SLG
Basin I Area ac
C
Area C
Notes
From 1993 Report:
C 2.27
0.95
2.16
D 1.23
0.95
1.17
E 2.49
0.95
2.37
F 1.48
0.79
1.17
G 0.83
0.48
0.40
From Current Report:
0-2 0.21
0.25
0.05
**
0-3 0.54
0.25
0.14
**
0-4 0.13
0.25
0.03
**
0-5 0.11
0.25
0.03
**
0-6 0.11
0.25
0.03
A-1 1.85
' ' 0:90
1.67
From Muller E. ' Y ngineenng.Report
A-2 0: 79
..6.45
0.36
From Muller Engineering. Report"
A-3' 0:13
0.35
0.05
From Muller Engineering Report
A-5. 1.31
0.20
0.26:From
fierEng'neering,Report
4B-1 1.23
0.95
1.17
4B-2 1.24
0.95
1.18
**
4B-3 0.69
0.95
0.66
**
H-1 0.93
0.41
0.38
**
H-2 0.66
0.75
0.49
**
H-3 0.48
0.95
0.46
**
H-4 0.27
0.54
0.14
**
H-5 1.87
0.95
1.78
**
Ponds 8.62
0.25
2.16
This includes 0.18 ac from original 1993 H Basin
Total: 29.47
18.27
Composite C for Basin: 0.62
Composite C for Basin (100-vr): 0.77
*From 1993 Preliminary Drainage, Erosion, and Storm Water Quality
Study for the East Vine Streets Facility P.U.D. Report.
"Basins A, B, 0-2, and H from the 1993 Preliminary Drainage, Erosion, and
Storm Water Quality Study were divided further for development design.
183-047
(Fort Collins)
11
��o
DETENTION POND SIZING BY FAA METHOD
Developed by
Civil Eng. Dept., U. of Colorado
'
Supported by Denver Metro Cities/Counties Pool Fund Study
Denver Urban Drainage and Flood Control District, Colorado
-----------------------
USER=Kevin Gingery...........................................................
EXECUTED ON 06-28-1999 AT TIME 13:51:09
PROJECT TITLE: Fort Collins Streets Facility - Overall Site Detention Pond -
**** DRAINAGE BASIN DESCRIPTION
BASIN ID NUMBER = 1.00
BASIN AREA (acre)= 29.47 - Comprised of the following contributing basins (exhibit on page 4):
'
Basins from 1993 Report: C. D, E. F, G
Basins from Current Report: 0-2, 0-3, 0-4, 0-5, 0-6, A-1,
A-2, A-3,
A-5, 4B-1, 4B-2, 4B-3, H-1,
H-2, H-3,
H-4. H-5, Ponds
-
RUNOFF COEF - 0.77 - Fran preVi0u5 edge
***** DESIGN RAINFALL STATISTICS
DESIGN RETURN PERIOD (YEARS) = 100.00
INTENSITY(IN/HR)-DURATION(MIN) TABLE IS GIVEN
DURATION 5 10 20 30 40 50 60 80 100 120 150 180
INTENSITY 9.0 7.3 5.2 4.2 3.5 3.0 2.6 2.1 1.7 1.5 1.2 1.0
***** POND OUTFLOW CHARACTERISTICS:
1
MAXIMUM ALLOWABLE RELEASE RATE = 10.5 CFS - Historic Q2 for Basin E1 (See page 3 for
exhibit and
OUTFLOW ADJUSTMENT FACTOR = 1 page 27 for calculation.
AVERAGE RELEASE RATE = 10.5 CFS
'
AVERAGE RELEASE RATE = MAXIMUM RELEASE RATE * ADJUSTMENT FACTOR.
***** COMPUTATION OF POND SIZE
RAINFALL RAINFALL INFLOW OUTFLOW REQUIRED
DURATION INTENSITY VOLUME VOLUME STORAGE
MINUTE INCH/HR ACRE -FT ACRE -FT ACRE -FT
-------------------------------------------
0.00 0.00 0.00 0.00 0.00
5.00 .9.00 1.42 0.07 1.35
10.00 7.30 2.30 0.14 2.16
15.00 6.25 2.95 0.22 2.74
20.00 5.20 3.28 0.29 2.99
25.00 4.70 3.70 0.36 3.34
30.00 4.20 3.97 0.43 3.54
35.00 3.85 4.25 0.51 3.74
40.00 3.50 4.41 0.58 3.83
'
45.00 3.25 4.61 0.65 3.96
50.00 3.00 4.73 0.72 4.00
55.00 2.80 4.85 0.80 4.06
60.00 2.60 4.92 0.87 4.05
65.00 2.47 5.07 0.94 4.13
70.00 2.35 5.18 1.01 4.17
75.00 2.22 5.26 1.08 4.17
80.00 2.10 5.29 1.16 4.14
85.00 2.00 5.36 1.23 4.13
90.00 1.90 5.39 1.30 4.09
95.00 1.80 5.39 1.37 4.02
100.00 1.70 5.36 1.45 3.91
105.00 1.65 5.46 1.52 3.94
THE REQUIRED POND SIZE = 4.17461 ACRE -FT
THE RAINFALL DURATION FOR THE ABOVE POND STORAGE= 75 MINUTES
'
F6 oA- M3 �oy--Ib Z:7-
I
I
I
I
I
I
I
I
I
I
I
I
I
CLIENT VAL)(fA H r ru r, JOBNO. (016-0
T:DINC PROJECT .5frces E&c-;1,Iy,' —CALCULATIONS FOR 11yVA0Z46r
Engineering Consultants MADE BY KIJ)G DATES/3-21 CHECKED BY —DATE —SHEET 3 OF
Af
7- ------- -- - -
.... ...... - ---- -------
----- --------
k 87 0,7, ; C c,F) 0 F;Auce 3-7
----- - --------- --- ......
6, sa
7
A;o Fi_
7;
..... -----
4-
AZI560
7
..... . . . ...... .. ...
gae
fps
77
0,4z
------- -------
18, G c-
Q100 h 25
..........
8 7 C C�) 0 ...... .. .....
O,Zo' +16)j .1 tk�-, 70
S = �J. al.
-16 YR: STORM A zm) 37ov,
7'
....... ....
---- ------
-
X3.0.
f
F4;-0- -1t(LBS NaS
J=== -71
—7-77
1
1
1
1
1
1
1
1
1
1
1
Fort Collins Streets Facility
Composite Rational Method Runoff Coefficient for Water Quality Pond A
Designer: SLG
Basin Area ac C
Area * C
Notes
From 1993 Report:
C 2.27
0.95
2.16
D 1.23
0.95
1.17
E 2.49
0.95
2.37
F 1.48
0.79
1.17
G 0.83
0.48
0.40
From Current Report
A=1 -.1.B5
0.90
. 1. 67
From Muller Engineermg;Repoit ;
A-2 0. 79
0.45,
. ° 0:36
From,Muller Engineering Report . _
A-5 _ 131
_ O PO
_ `; 0.26
From"Muller Engineering_Report
4B-2 1.81
0.95
1.72
**
413-3 0.79
0.95
0.75
**
Total: 14.851
12.01
Composite C for Basin: 0.81
*From 1993 Preliminary Drainage, Erosion, and Storm Water Quality
Study for the East Vine Streets Facility P.U.D. Report.
"Basins A, B, 0-2, and H from the 1993 Preliminary Drainage, Erosion, and
Storm Water Quality Study were divided further for development design.
183-047
(Fort Collins)
0
------------------
DETENTION POND SIZING BY FAA METHOD
Developed by
'
Civil Eng. Dept., U. of Colorado
Supported by Denver Metro Cities/Counties Pool Fund Study
Denver Urban Drainage and Flood Control District, Colorado
USER=Kevin Gingery...........................................................
EXECUTED ON 06-28-1999 AT TIME 13:54:07
PROJECT TITLE: Fort Collins Streets Facility - Water Quality Pond A
****
DRAINAGE BASIN DESCRIPTION
BASIN ID NUMBER = 1.00
BASIN AREA (acre)= 14.85 Changed from 1993 report due to new
delineation of sub -basin
'
RUNOFF COEF 0.81 drainage in Basins A and B. Runoff
coefficient calculation on
previous page.
***** DESIGN RAINFALL STATISTICS
'
DESIGN RETURN PERIOD (YEARS) = 2.00
INTENSITY(IN/HR)-DURATION(MIN) TABLE IS GIVEN
DURATION 5 10 20 30 40 50 60 80 100 120 150 180
'
INTENSITY 3.2 2.5 1.8 1.5 1.2 1.0 0.9 0.8 0.6 0.5 0.4 0.4
***** POND OUTFLOW CHARACTERISTICS:
MAXIMUM ALLOWABLE RELEASE RATE _ .1 CFS - Considered small enough
to provide for approximately
OUTFLOW ADJUSTMENT FACTOR = 1 40-hour detention time and conservative pond size.
AVERAGE RELEASE RATE _ .1 CFS
AVERAGE RELEASE RATE = MAXIMUM RELEASE RATE * ADJUSTMENT FACTOR.
***** COMPUTATION OF POND SIZE
RAINFALL RAINFALL INFLOW OUTFLOW REQUIRED
DURATION INTENSITY VOLUME VOLUME STORAGE
MINUTE INCH/HR ACRE -FT ACRE -FT ACRE -FT
-----------------------------------------------------
0.00 0.00 0.00 0.00 0.00
5.00 3.20 0.27 0.00 0.27
10.00 2.50 0.42 0.00 0.42
15.00 2.15 0.54 0.00 0.54
20.00 1.80 0.60 0.00 0.60
'
25.00 1.65 0.69 0.00 0.69
30.00 1.50 0.75 0.00 0.75
35.00 1.35 0.79 0.00 0.78
40.00 1.20 0.80 0.01 0.80
45.00 1.10 0.83 0.01 0.82
'
50.00 1.00 0.84 0.01 0.83
55.00 0.95 0.87 0.01 0.87
60.00 0.90 0.90 0.01 0.89
65.00 0.88 0.95 0.01 0.94
70.00 0.85 0.99 0.01 0.98
75.00 0.82 1.03 0.01 1.02
80.00 0.80 1.07 0.01 1.06
85.00 0.75 1.07 0.01 1.05
90.00 0.70 1.05 0.01 1.04
'
95.00 0.65 1.03 0.01 1.02
100.00 0.60 1.00 0.01 0.99
105.00 0.58 1.01 0.01 0.99
'
110.00 0.55 1.01 0.02 1.00
--------------------------------------------
THE REQUIRED POND SIZE = 1.058181 ACRE -FT
THE RAINFALL DURATION FOR THE ABOVE POND STORAGE= 80 MINUTES
�_;O
I
n
I
I
I
I
I
Fort Collins Streets Facility
Composite Rational Method Runoff Coefficient for Water Quality Pond B
Designer: SLG
Basin
IArea ac
C
Area * C
Notes
From Current
Report:
0-2
0.21
0.25
0.05
**
0-3
0.54
0.25
0.14
**
0-4
0.13
0.25
0.03
**
0-5
0.11
0.25
0.03
**
0-6
0.11
0.25
0.03
**
A-3
0.13
, 0.35
0.05
From Muller Engineering Rep6rh
4B-1
1.23
0.95
1.17
**
H-1
0.93
0.41
0.38
**
H-2
0.66
0.75
0.49
**
H-3
0.48
0.95
0.46
**
H-4
0.27
0.54
0.14
**
H-5
1.87
0.95
1.78
**
Pond B
0.85
0.25
0.21
This includes 0.18 ac from original 1993 H Basin
Total:
7.521
1 4.95
11
Composite C for Basin: 0.66
"Basins A, B, 0-2, and H from the 1993 Preliminary Drainage, Erosion, and
Storm Water Quality Study were divided further for development design.
183-047
(Fort Collins)
i
1 3l
I
DETENTION POND SIZING BY FAA METHOD
' Developed by
Civil Eng. Dept., U. of Colorado
Supported by Denver Metro Cities/Counties Pool Fund Study
Denver Urban Drainage and Flood Control District, Colorado
------------------------------------------------- -
' USER=Kevin Gingery...........................................................
EXECUTED ON 06-23-1999 AT TIME 15:43:53
PROJECT TITLE: Fort Collins Streets Facility - Water Quality Pond B
**** DRAINAGE BASIN DESCRIPTION
BASIN ID NUMBER = 1.00
BASIN AREA (acre)= 7.52 - Changed from 1993 report due to inclusion of railroad swale and
RUNOFF COEF 0.66 sub -basins 4B-3 and A-3. Runoff coefficient calculation on
previous page.
DESIGN RAINFALL STATISTICS
DESIGN RETURN PERIOD (YEARS) = 100.00
INTENSITY(IN/HR)-DURATION(MIN) TABLE IS GIVEN
r
11
n
DURATION 5 10 20 30 40 50 60 80 100 120 150 180
INTENSITY 3.2 2.5 1.8 1.5 1.2 1.0 0.9 0.8 0.6 0.5 0.4 0.4
***** POND OUTFLOW CHARACTERISTICS:
MAXIMUM ALLOWABLE RELEASE RATE = .1 CFS - Considered small enough to provide for approximately
OUTFLOW ADJUSTMENT FACTOR = 1 40-hour detention time and conservative pond size.
AVERAGE RELEASE RATE = .1 CFS
AVERAGE RELEASE RATE = MAXIMUM RELEASE RATE * ADJUSTMENT FACTOR.
***** COMPUTATION OF POND SIZE
-----------------
RAINFALL
RAINFALL
INFLOW
OUTFLOW
REQUIRED
DURATION
INTENSITY
VOLUME
VOLUME
STORAGE
MINUTE
INCH/HR
ACRE -FT
ACRE -FT
ACRE -FT
----------------------------------------------
0.00
0.00
0.00
0.00
0.00
5.00
3.20
0.11
0.00
0.11
10.00
2.50
0.17
0.00
0.17
15.00
2.15
0.22
0.00
0.22
20.00
1.80
0.25
0.00
0.25
25.00
1.65
0.28
0.00
0.28
30.00
1.50
0.31
0.00
0.31
35.00
1.35
0.33
0.00
0.32
40.00
1.20
0.33
0.01
0.33
45.00
1.10
0.34
0.01
0.34
50.00
1.00
0.34
0.01
0.34
55.00
0.95
0.36
0.01
0.35
60.00
0.90
0.37
0.01
0.36
65.00
0.88
0.39
0.01
0.38
70.00
0.85
0.41
0.01
0.40
75.00
0.82
0.43
0.01
0.42
80.00
0.80
0.44
0.01
0.43
85.00
0.75
0.44
0.01
0.43
90.00
0.70
0.43
0.01
0.42
95.00
0.65
0.43
0.01
0.41
100.00
0.60
0.41
0.01
0.40
105.00
0.58
0.42
0.01
0.40
110.00
0.55
0.42
0.02
0.40
-----------------------------------------------------
THE REQUIRED POND SIZE = .4301541 ACRE -FT
THE RAINFALL DURATION FOR THE ABOVE POND STORAGE= 80 MINUTES
3z
Fort Collins Streets Facility
183-047
Water Quality Ponds A & B Volume Calculations
(Fort Collins)
Designer: S. Gentry
1. Water Quality Pond A
Contour Area (ft^2) Volume (f A3)
Volume (ac-ft)
46 350.00
18993.49
47 52350.00
27070.01
47.5 55950.00
Total: 46063.51 =
1.06
Needed Volume: =
1.06
Surplus =
0.00
Water Quality Pond A volume is adequate for the situation.
11. Water Quality Pond B
Contour
Area (f A2) Volume (ft^3)
Volume (ac-ft)
47
1.00
9184.95
48
27388.36
14201.45
48.5
29429.68
Total: 23386.40
= 0.54
Needed Volume:
= 0.43
Surplus
= 0.11
Water Quality Pond B volume is adequate for the situation.
1
1
1
i
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
Fort Collins Streets Facility 183-047
Detention Pond Volume Calculations (Fort Collins)
Designer: SLG
The survey certification after completion of 1993 construction shows an increase
in contour size from what was planned. Therefore, the volume for the detention pond
was recalculated.
Contour Area (ft^2) Volume (ft^3)
44 9585.12
28575.40
45 53496.61
85167.48
46 121413.10
Total:
113742.88 =
Volume (ac-ft)
2.61
Top of pond is 4947 feet. The emergency overflow weir is set at 4946 feet.
Setting the maximum water surface elevation for the 100-year storm
at 4946 feet allows for one (1) foot of freeboard.
Volume Available for Detention:
Pond Volume (ac-ft)
Water Quality Pond A 1.06
Water Quality Pond B 0.54
Detention Pond 2.61
Total. 4.21
Volume needed for detention is: 4.18 ac-ft
Volume available for detention is: 4.21 ac-ft .s
Surplus of 0.03 ac-ft
Current detention pond volume is adequate for the situation.
3'_;�
11
L
I
I
I
7-
L
I
I
I
I
I
EROSION CONTROL
I
1
1
Project: Fort Collins Street Facility
Project No: 183-049
Erosion Control
Rainfall Performance Standard Evaluation
Developed
Basin
Erodibility
Zone
Asb
(ac)
Lsb
(ft
Ssb
%
Lb
(ft)
Sb PS
46-1
Moderate
1.16
360
2.0
413-2
Moderate
1.55
495
2.0
413-3
Moderate
0.44
370
2.0
Total
1
1
3.151
1
1 4281
2 80.3
Lb = Sum AsbLsb /Sum Asb
= 1.13x290+..+0.46x302 /3.16
Sb = Sum AsbSsb /Sum Asb
= 1.13x2.0+..+0.46x2.0 /3.16
PS(during construction =
80.3
Table 5.1 City E/C Manual
PS (post construction) =
94.5
PS/0.85
n
ILA
c
0
0 co
c I
C U N C N m
C G� C
E—OO >
E O m Comm Fn m m> C
� N � N
c°�v�icaa¢ma¢Unm
O O O p 0 0 0 0 0
O O O p 00 00 In O O
t.z O O O
T
w
LL
a.
L
c
oo�u,000m�
0 o 0 o p o 0 0 0 0
d 0
00
m
M j
LL.
U
N V O
. U
U
U Q o y
y
C
o M 7 O
C
O
{i�a'w
a
G C
O
U �
—
2
N N
0
a)i N
O
y c
U
O> 0) N
0— c d 0= 0 t N
N
z
w
U
p I1 N
C
d d d
Q7
V
m O
;
C7
toOl L>> 3
O O o
LL
aaa
_.
wui
�mw< c7( wm U)
�ooao
�c
cLo(
LU
w
a
LU
w
0
0
0
a
N
C
O
N
Lcoo
roc-)
U
O
o
O
Cl
o
0
u
�a
U
0
0
0
0
0
0
U
U
U
U
d
775
7
N
y
N
y
Of
N
N
0
N
0
co
LO
-It
LO
y
Oai
Q v
c
R �
G _
7
mmm
co
It
I-T
V
0
O
N \
00
a
m
m
0
N
N
7
fN
co
a�
.r
rn 05 ca
0-
0)
v
cc
c
N O
N U
C y Co U
0) E
E N N
O0- 0)U
U w a Q
c
0
C M
C U N C C m C NCO
C
w O N E- N N M > L
O c0 N O O> C
y C
E 0 Co M 'N CO CO L N
UfpFo-000OOQ�(nCL m
O O O p 0 0 0 0 0
L OOOp0000 L000
0�O�e-000�-�
V
1
a
'°
tL
N
oo�cr,000co�
L O O O p 0 0 0 0 0
a+
M
lL
C)
N
!� O
RU
U
4
O u
N
t M
C
7
C
O
U.
W w
a
V .
O C
U °
—
N0-0
7
U� 0 N
O
CDN
N� j 0)L N
(L -a U N
Z
0 o
L .
0m — O c m
0
_ co 0
O O
O
d O
d = O. M N Co -0
LU
ILLILL0.
2mo¢C9cr)in'cn2tp
>,
'OR
000
rn
rn
rn
rn
w
Lov
Q
0
w
IL
m
0
w
C)
a
U)
C
O
,
r
N
a
0
0
0
u U
o
0
0
A
U
C
C)
C)
0
0
0
0
0
0
N
cN
E2
U
mccom
j
?
�
32
N!
ca
m
w
m
.0
c
L
Q
Q
Q
Ln
Lo
„(D
In
r,
Q �
c
.y
R G
7
mmm
N
vvv
0-
fn o
O)
a�
L C
'N
CO
El
-o
m
'O
cc
C
N O
N U
C y O U
N > E j
cr
O N
J w d Q
I
J
1
1
�J
n
I
n
1
L
aT+
R
U. N
d O
w
(n 7 C
N V O
C �p
o U C
rn
Ugoy
E
M c O
O CO 3 L
N
W
LL d'W
;
O
U
O
c
C
Z
O
V v v
c
O
o O O
O
IL IL IL
w
co
'D
E
0
•�
o
w
d
o
m
o
�
IL
L
o>
0
:?>
voOzO
OOMd�•
�
N
N
cocDuico
c+iov
V
am
co00
r,,Oo
oocIJcnOD
vn.
l6
CV
00
N�
0
CO
ce)
N
EA
611,60
ffl
H9
fA
69
_
N
O
O
O
Ict
o
8-
r
co
O
U
L
M
++
M
C
�
ffl
ffl
Efl
Efl
C
i
U)
H
�
'ITCO
04
CO
04
C
to
N
R
N
O
to
c d
U 3
L
�
U
>
U
c R
C 41
c
CD
CO
CL
c
CD
>EL
W
�cR
cnU'
IL
U)UH
1]
1
1 CHARTS, TABLES & FIGURES
I
I
I
I
I
I
I
I
I
No Text
1
1
1
1
1
w
1
1
1
1
1
1
1
DRAINAGE CRITERIA MANUAL
50
30
1- 2 0
Z
to
U
W
>Z 10
2
ul
a
O 5
4n
W
c 3
0
U 2
C
tit
F
Q
�
►
r
1
RUNOFF
o \C
la
e
•
T
y
v
r
I� o f el rt
mt 1 �° j o� •
4T
I
1
I
I I�
�v � � ;' I
t ?1
I
I
�
�
�
�I
1
•
Q
4t
I
e
•
4°
W
•
QT .
I
I
I 1
I I
1
i
1
1
1
1
1 1
1
I
1 1
1
1 I
I
I
I
I
I
I
I I I
I
I
I
I
I
l
t
I
I
I
I
I
yi
11 41
1
1I
I
I
I
I
Figure 3-3
.2 .3 .5 1 1 v.9 2 3 5 10 20
VELOCITY IN FEET PER SECOND
ESTIMATE OF AVERAGE FLOW VELOCITY FOR
USE WITH THE RATIONAL FORMULA.
' MOST FREQUENTLY OCCURRING "UNDEVELOPED°
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
0.8
0.7
u- 0.6
w
Z 0.5
Cr
> 0.4
O
F
a 0.3
W
O"
C7
Z 0.2
O
Z
O
a 0.1
MAY 1984
EXAMPL
0.0 3 4
0 1 2
FLOW INTO INLET PER SO. FT. OF OPEN AREA (CFS/FT2)
Figure 5-3
CAPACITY OF GRATED INLET IN SUMP
(From: Wright -McLaughlin Engineers, 1969)
5-11
DESIGN CRITERIA
Table 3-3
'
RATICNAL METHOD RUNOFF COEFFICIENTS FOR CCHPOSITE ANALYSIS
Character of Surface Runoff Coefficient
Streets, Parking Lots, Drives:
'
Asphalt.. 0.95
Concrete........................ 0.95
Gravel ....................................... 0.50
Roofs.......................................... 0.95
Lawns, Sandy Soil:
'
Flat<2$..................................... 0.15
Average 2 to 7$.. 0.1
Steep>7%.................................... 0.20
'
Lawns, Heavy Soil:
Flat<2$.............................. 0.20
Average 2 to 7%.............................. 0.25
Steep>7%..................................... 0.35
'
3.1.7 Time of Concentration
In order to use the Rainfall Intensity Duration Curve, the time of
concentration must be known. The time of concentration, T,, represents the
'
time for water to flow from the most remote part of the drainage basin under
consideration to the design point under consideration. The time of
concentration can be represented by the following equation.
Tc = to, + tt .
Where:
T, = Time of Concentration, minutes
'
t„ = overland flow time, minutes
tt= travel time in the gutter, swale, or storm sewer, minutes
'
The overland flow time, t,,, ,can be determined either by the following equation
or the "Overland Time of Flow Curves" from the Urban Storm Drainage Criteria
Manual, included in this report (See Figure 3-2).
'
L87(7.1-(Cf)D1/2
TOV s1/3
'
Where: T„ = Overland Flow Time of Concentration, minutes
S = Slope, %
C = Rational Method Runoff Coefficient
'
D = Length of Overland Flow, feet'(5001 maximum)
Ct = Frequency Adjustment Factor
The travel time, tt, in the gutter, swale, or storm sewer can be estimated with
the help of Figure 3-3.
3.1.8 Adjustment for Infrequent Storms
1
The preceding variables are based on the initial storm, that is, the two to ten
year storms. For storms with higher intensities an adjustment of the runoff
coefficient is required because of the lessening amount of infiltration,
depression retention, and other losses that have a proportionally smaller
effect on storm runoff.
These frequency adjustment factors are found in Table 3-4.
May 1984
Revised January 1997
1 3-5
•
Design Criteria
Table 3-4
11
1
RATIONAL METHOD FREQUENCY ADJUSTMENT FACTORS
Storm Return Period Frequency Factor
(years) Cr
2 to 10 1.00
11 to 25 1.10
26 to 50 1.20
51 to 100 1.25
Note: The product of C times Cf shall not exceed 1.00
3.2 Analysis Methodology
The methods presented in this section for use in the determination of runoff at
specific design points in the drainage system are currently under review by the
Stormwater Utility. Until detailed criteria for hydrologic modeling are developed, the
accepted methods for hydrologic analysis are (1) the Rational Method and (2) UDSWM2-
PC. The Stormwater Utility shall determine circumstances requiring computer modeling
with UDSWM2-PC. Early contact with the Stormwater Utility is encouraged for the
determination of the appropriate method. Where applicable, drainage systems proposed
for construction should provide the minimum protection as determined by the methodology
so mentioned above.
3.2.1 Rational Method
The Rational Method is recommended only for sites less than 5 acres. The runoff
may be calculated by the Rational Method, which is essentially the following
equation:
Q = CfCIA
Where Q = Flow Quantity, cfs
A = Total Area of Basin, acres
Cf= Storm Frequency Adjustment Factor (See Section 3.1.8)
C = Runoff Coefficient (See Section 3.1.6)
I = Rainfall Intensity, inches per hour (See Section 3.1.4)
' 3.2.2 UDSWM2-PC
For circumstances requiring computer modeling, the design storm hydrographs
' shall be determined using UDSWM2-PC. Basin and conveyance element parameters
shall be developed from the physical characteristics of the development. Refer
to the UDSWM2-PC User's Manual* for modeling methodology and development.
' *Urban Drainage and Flood Control District, March 1985
3.2.2.1 Surface Storage and Infiltration
' Table 3-5 gives those values for surface storage for pervious and
impervious surfaces. Table 3-6 gives the infiltration rates to be used
with UDSWM2-PC.
' Table 3-5
VALUES FOR SURFACE STORAGE
' (All Values in Inches)
(For Use with UDSWM2-PC)
Impervious Areas .................. .100
' Pervious Areas .................... .300
' May 1984 Design Criteria
Revised January 1997
' 3-6
I
h
1
t
1
I
L
0 010+000
o V V UI U1 In
u� ao ao ca eo co
o rnolrno,000000
. . . . . . . . . . .
o V V v V In In In In U; U1
� wwwmoococ0000
0 0orno+o1a+01o10+0101010+000
. . . . . . . . . . . . ... . .
o .rvvvvvvvvvvvUllnln
M OtOooOOW OODOtOaoOtOOoo
o n. . . OO 10 1. o1. o, o, 0l rn rn o+ rn o, rn o, o+ rn o+ of rn
. . . . . . . . . . . . . . . .
o er v v v v v v v v v v v v v v� v v v v
N ODO OCOOOCOOCD0000 OD0O000000
O O . . M. U. 10 10 10 10 n. n. n. n. n n n. n. n 0
0 00 t0 00 C! CD
O o vV V VV vV V V V vV V V srV vV vvvvvvvv
A rl oo O O O O ao O O ao ao t0 O O t0 t0 ao t0 ao 0o t0 O O O O O w
p
o cOc.�MV�U1InIn1D1D1D1D1D1DnnnnnnnnnncoOoaD
a a, Mvvvvvvvvvvvvvvvvvvvvvvvvv
co co w w oD 00 00 00 00 00 00 00 0o CD 00 00 00 00 00 00 0o co Co co.0o 00
O tD O N M V' V' U) U) U1 U1 10 O 10 t0 10 1D 10 10 10 10 n n n n n n
. . . . . . . . . . . . . . . . . . . . . . . . . . .
0 CD M V' V' el' V' V' e!' V' V' V' V' •d' V' V' V' V'
IZ-1 000000000ODO Ol�OOO 0000 CO co O'0000000 CO 00
a O v 01 rt N M M v v v v U� 4i U� U7 U� 11 U7 In Ut 1D 1fl 10 10 •D 10 n
a
O n enMvvvvV0vvvvvvvvvvvvvvvvvvv
U 00000D W 00OD000000OD00OD00OD000D0CDCO000000000
[i O 9100!91iNNM11MMv V'vvvv V'i9!L91fltn101D
O 1D MMMvv V'vvvvvvv V'vvv V'vvvv-it vvv
G. 00 O OD 00 CO 00 00 00 O 00 OD OD OD 00 10 00 00 00 0D OD 00 O 0D CO 00 CD
49 � C) In01InnOD0%0orIrIrINNNNN MN)MMMvvvvv
OD W U1 N M M M M M V
O CO C0 OD 00 00 CO 00 00 OD OD 00 CO CD 00 OD 00 CO OD CO OD 0 00 00 C0 CD
W N W
a p W In H m rI M V' u1 In 1D 1D n n n ao 00 00 ao OD co o+. 01 01 0 0 0 0 0
g• y a 4 N M M M M M M e N N M M M M M M M M M M M M M 4 4 4 4
o W 00 0 CO CO CD O O 00 CD W O O D CD 00 CO 00 O 0 OD 00 0 CD 0 0 OD
O 1OU1000riNMV' V'1111f11n10101D1D10nnnn00000D0101
E+ . . . . . .
0 V' rI N N M M M M M M MMMM M PI A M M M M M M M IM MM
00 CD OD CD 00 OD OD O OD 00 00 00 OD 0 00 OD 00 OD CD 00 OD 00 00 00 OD 00
W
U U) .irIU1n0o00rINNMMM V' V'd'd'tf'tnlnln1D1D10nn
M rI N N N N MA M M M M M M MA MA M MA MA M M M M
00 00 00 00 00 O 0 CO 00 00 W 00 O OD 00 00 00 OD 00 CO CO 00 CO OD 00 CO
O O M N W C0 01 0 rI N N M M M V V V V V v 10 U1 U1 U1 10 1D t0 10
(1' M O rl rl ri rl N N N N N N N N N N N N N N N N N N N N N
rA OD OD OD OD OD OD 00 00 00 CD OD 00 00 O OD 00 00 00 00 CO O OD CO 00 00 CD
In U1 In 01 N M V U1 10 n n n CD co OD 0% ON 0% 0% O -ON 0 0 0 0 0 0
a
a N OtOO4rIrl 4,444V;ririrl ;44eIrIrINNNNNN
n OD O OD 0 OD OD OD OD CO 00 O OD CO O 00 OD OD OD 00 OD O0 OD CO OD OD
.7. O V'1n OM Ln WWcD 0% 000 rI•i r4' 4 N N N N CM M r1 M MM
�. N 00010000008C;•irlrlrl•-Irlrl•irl•irlrlrl•-lrlrl
n n 00 CO O 00 OD O 00 00 OD 00 OD Co OD 00 CO 00 OD 00 O 0D OD 00 00 O
In OONOOrIVInnnOD010%00rIrlrlrlrlNNNMMMMM
rl tDODOD010�0;010%010101000000000000000
nnnnnnnnnnn0000CID OD00OD0000OD0000WCO00OD
O tOMOV n010V-4NMMvvm0LO0w 01010nn101010
rl V' 1D n n n n OD CO O 0D 00 aD t0 O O O t0 O ao O 00 O O tD 00 CD
n n n n n n n n n n n n n n n n n n n n n n n n n n
In 010 Q W n 00 00 n n n%0%0 VD In V 1wm MNN 0110 v.-10110
O ONNNNNNNNNNNNNN N44N4441lr100
rnnnnnnnnnnnnnnnnnnnnnnnnn
3E-4 00000000000000000000000000
O0&4 o0000000000000000000000000
azw rINMV In10ncOCI�OrINMV In10n00610UtOIf10tn0
WWv Hrl iHf-lrl•-IrIrIrINNMMvv0
14
MARCH 1991
8-4
DESIGN CRITERIA
I
n
L,
t
1
1
1
1
Table 8B C-Factors and P-Factors for Evaluating EFF Values.
Treatment
C-Factor
P-Factor
BARE SOIL
Packedand smooth................................................................
1.00
1.00
Freshlydisked........................................................................
1.00
0.90
Rough irregular surface...........................................................
1.00
0.90
SEDIMENT BASIN/TRAP.................................................................
1.00
0.50(11
STRAW BALE BARRIER, GRAVEL FILTER, SAND BAG .........................
1.00
0.80
SILT FENCE BARRIER.....................................................................
1.00
0.50
ASPHALT/CONCRETE PAVEMENT ...................................................
0.01
1.00
ESTABLISHED DRY LAND (NATIVE) GRASS ..........................
See Fig. 8-A
1.00
SODGRASS.................................................................................
0.01
1.00
TEMPORARY VEGETATION/COVER CROPS ....................................
0.4512)
1.00
HYDRAULIC MULCH @ 2 TONS/ACRE...........................................
0.1013'
1.00
SOIL SEALANT....................................................................0.01-0.60j41
1.00
EROSION CONTROL MATSBLANKETS............................................
0.10
1.00
GRAVEL MULCH
Mulch shall consist of gravel having a diameter of approximately
1 /4" to 1 1 /2" and applied at a rate of at least 135 tons/acre..............
0.05
1.00
HAY OR STRAW DRY MULCH
After nlantino crass seed, apply mulch at a rate of 2 tons/acre (minimum) and adequately anchor,
tack or crimp material into the soil.
Slope (%)
1
to
05..............................................................................0.06
1.00
6
to
10.............................................................................
0.06
1.00
11
to
15.............................................................................
0.07
1.00
16
to
20.............................................................................
0.11
1.00
21
to
25.............................................................................
0.14
1.00
25
to
33.............................................................................0.17
1.00
>33..........................................................................
0.20
1.00
NOTE: Use of other C-Factor or P-Factor values reported in this table must be substantiated by documentation.
(1) Must be constructed as the first step in overlot grading.
' (2) Assumes planting by dates identified in Table 11-4, thus dry or hydraulic mulches are not required.
(3) Hydraulic mulches shall be used only between March 15 and May 15 unless irrigated.
(4) Value used must be substantiated by documentation.
1
N..
' MARCH 1991 8-6 DESIGN CRITERIA
---
-
- - -
EAST
VINE DRIVE
-
—___---_—___,_—_—_--_--_—_--—_—
---
IInnI
-
---
----
Gam_—
-a
_____
____
RAILROAD
__ ___ ___ _ __
___ ___ ___
___ ___ ___ ___ _ ___
_ _
____ - -
`'
5
___ ___ ___ ___
-
-"
--
-------=
=�-----
---
___---
1431
•
i
Ik
I
•
----------------
1 i
------------
LDT .,,
�I
at ,
•-'«R
LOT 4B
I
i
�IIMIN
_____-----
___O"
--_--___---+t----_ _--
I *1Y�\I_�IL�I��I��I��Il�ll�ll�ll�ll�l��ll�ll�el __ --1---_I r
--------------------
c_
___
r
-- P
a{I II `
City of
Fort Collins
Streets
Department
i De -Icing
1 Facility
' I•-� Po Box SW
m M Iw FM Comm 00 wu
VAUGHT FRYE
LEGEND
ARC R I T E CTS
W WPXG WATER V&W
IXISTNG PRE"n"iAV!
EJ EnSIMG WATER MFTEEI rlga�le NSIN�W n,�..m-.rv�.�
be asdelb •Nr
® MINING SWITARY MMHM
RNI
EpSnHG $fCflY INLFT � w � ma. I
a� l EMSnNG NP1T Pbl >e�/ sw
e ECSTI KRIEV PIX£ Tr IYI Yso IMrpWngb
❑ EMImNG S.ECTMC VALLT TWeem m¢In�
�\ EASTXG WARD PJSi
I j En"ING TREE 'p "•• an•'•"-
NeIIP DISTXG CNNN UN" FENCE µ 9701,8¢4an m ���
/mI y� FAR Moww�
EgsnNG CCMBII FENCE
—ne— MnNG UNITARY lJRE RA), �Mle,thead OF ew
ENLSnNC 51gLV SERER 1, e^o�/Wx.nel1e
x
—LC[— METRIC CXDFREAWND EIECTMC �Crn Ah"An
—ne— MPING O PRFH AD EL£C1Rn Kv na .� m mem
—Gu_ EgSnNG GM1S XXE 4en.ow
x— EMSTNG WATER UNE yv
—T—T� EMISTNG RNLROAD In Ueeerbb. Dale
---------- DIPPING WT UNE rim oµ fmrtl
ENLSTING CCIITWR
MIIMIIMIIM EOrnuG el9N BWw.VtY - - -
NX- WSTNC BASH DESMAnCN _ _ -
Wler
Design Development
,.e, N: 83-11 Rea" Na, In
MXnM en vp
LtiLy
of Port CORim. Cobrxdo
LOT 04B•
RRELIMINARr
GT�TY PLAN APPROVAT.
NOT sFORSIEFT
APPROYm:
DM drlev
Gle
M on
b1E°®
EXISTING
C LUTILITYMOnNCIFK
OFE« en
CONDITIONS
CENTER 01 COLgVyry
1-800-922-1987
nuay
m
amMm e
PWb W furYm
m
ue•4 We4er•
we
EXHIBIT 1
WEC1.iD Bn
—
r
L G.
EAST VINE DRIVE --
-----
50 mill
_� _ W -----------
bet FIVELINE xE=,k----- - - - - - - - - - - - - - - - -
in
I
A
in
DEVELOPED SITE HYDROLOGY
TIDN
MFA
Imo)
(2
1
uM1
(eN)
18-1
1 1.18
1 ABS
I 1.W
28
R.B
A8-3
1 %55
AGS
LD
A3
14,I
Al
6N
A95
TOTAL
1 >IS
1-
-
-
-
_ STANDARD xW81IX1 CONTROL CONSTRULTpN PLAX NOTES
The City If Fort imply, Stormil UtIfy prolk off" reform Crop be .1 Til
or Emit a nmor prim to my em.m.,m m p o� to
my
ime ei
rtifying emblem
rmor
i be Coffee on I
moryor pmr+.*ua., ew be redled Or the Colonel tiny. m menu, P. a e.sa^y knm fe
wwrvu+a .nun mi=.a rs u..n rut m."roil `MM pm ,.. be
of Momen�Onu� p.mj Ill e. gist t. a�r.tf�m :�uiiim er ri av1deprob^a
mork moo Crooke, miji n...wmpq of form
mr of .olm 11
or vbfroin them a(o /mua.(bm.=roprvb nf) of notemounted iu .me
euoommurry
aimwn=�+by the S.-mow Cliff.
Cry Coffee MA by w.n oLOWm„ u
of me to Armorterrim .. A mum •mwm a#n, Nww "r Imprinter m,mmima by tro rnr
of rn boom MrenAymq o+=k^ement
ml %Ow frommer Imfory 1.11 Al be Centered and WI or
my..not to open AM romen bit... eenwpome em i. a ma.m mp i,a
nor mien empood too (10) Plot N Cement nmpe,nm be
rpool Cry mdr.mt ..n.. .Nr.a., � itr,sr.� b son w5' ow frompod from mkmmmp,
•oppi me r "en,
City Compromme propol Me beryl xprg. or Uqa"lit of my mor
� mento City moomporm by or fork my onnor. My beep me sae n....oel by the o..w.w.. 1nv° tinent °i• nu mxsa
mil pl.lphi 1.1
•1.1.1,
1r1•
eml Implies
pop- ul
rzr
prim ky
'a
m�a
LEGEND
Etl51Wc WATER VALVE
f j
E US1l TREE
-T-T-T
EXISTING RIJIAD/L
A��
M�
PPCPOSED SPOT p ATCN
(St] Ot nb t cDWDR, CNUAdU
�pd1
DTQ�Ct�Y
PLAN APpttDVAt.
}(
EXISTING FINE NYpUVT
EMIrnxG MAN UNK PEACE
----------
EMISMC LOT U E
�
EX I SPOT E VAnq!
mEuwxARr
AwaoAmmy
Gy ma`s
_
m
Q
EXISTING WATER METER
EASING COARNATON PENCE
.- -�Wx -
NG C
EASICNTWR
RDW ANSI
1
®
EXISTING SANITARY MANI
—m—
ENSTNG SNTAAY LWE
� Sl
PRCPDYD O%MIR
—R
9LT fTNC£
CHECKED BY:
1; a IaNnlm NNN
—Dow-
EXISTING STMIA III
MONG SIONN gNF
RIDPOSFD ST09N SEVER
�Ea(a�WWO�E
OECKED BY:
m
��Gxy
>{I
EAJS1l uT P
4NEE
�—_
ElxnWWRIC xG UNGERND ELECT
=11=11=11M
BASININCURIOSITYINCURIOINCURIOSITYx INCURIOSITY
p�e a
7V00-922-1987
cEGEO eY:
e
ENSTNG All Poi
ilyCrnmo'n
opa3ws
nw
oc—.
DUSTING OIIE IEAD ELECTNIC
IbT
BASIN ID
.,
�i,u,m
��'C""n
aEGUD eF.
❑
EASING ELECTRIC VAULT
wS—
N
BASIN AMES
Tel
ENTERS GAS LINE
o
ENISTNC WARD POST
—w—
EXISTING WATER TINE
CHEMED BY:
hle
City of
Fort Collins
Streets
Department
De -Icing
Facility
VAUGHT • FRYE
ARCHITECTS
ftp iw ,ra�msu ,�ampp.®�
fiiiiEl:,,n
lot Noth
lobby IM
/Hume• III
em
v/en.am
Design Development
Npl.e• N.. �o-m "ti a m M
LOT W4BO
3RADING, DRAINAGE
& EROSION
CONTROL PLAN
mop Aeeo,agp R Rpmope
immill "I
EXHIBIT 2