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FMrrITY OF FinalReport
FORT CO�b UTat� a Date 3 0i,
Final Dramage Report
for
Fort Collins Coloradoan
Laruner County Colorado
May 27 2004
NORTHERN
ENGINEERING
NESERVICES, INC
Final Drainage Report
for
Fort Collins Coloradoan
Larimer County, Colorado
May 27, 2004
Prepared For:
Coloradoan
1212 Riverside Avenue
Fort Collins, CO
80525
Prepared By:
NORTHERN
ENGINEERING
SERVICES, INC.
420 S. Howes, Suite 202 Fort Collins, Colorado 80521
Phone: (970) 2214158 Fax: (970) 2214159
Project Number: COD:03-050
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NE
NORTHERN
ENGINEERING
SERVICES, INC.
May 27, 2004
Fort Collins Utilities - Stormwater
P.O. Box 580
Ft. Collins, CO 80522
Attn Basil Hamdan,
RE: Fort Collins Coloradoan
Fort Collins, Larimer County, Colorado
Project Number: COD:03-050
Dear Basil:
Northern Engineering is pleased to resubmit this Final Drainage Report for the Fort Collins
Coloradoan Office for your review. This report summarizes the final drainage design for Fort Collins
Coloradoan Office. The design of the drainage infrastructure conforms to the current City of Fort
Collins Standard Design Criteria and Standard Construction Requirements dated January 2003. The
plans and calculations have been revised per comments received from the City dated March 31, 2004.
If you should have any questions or comments as you review this report, please feel free to contact me
at your convenience.
Sincerely,
NORTHERN ENGINEERING SERVICES, INC.
Mark Oberschmidt, PE
Project Engineer
420 SOUTH HOWES, SUITE 202 / FORT COLLINS, COLORADO 80521 1 970.221.4158 / FAX 970.221.4159
Table of Contents
VICINITY MAP
IINTRODUCTION
.................................................................................................................. 2
II
SITE LOCATION AND DESCRIPTION..............................................................................
2
ASite
Location.......................................................................................................................2
BSite
Description...................................................................................................................
2
III
DEVELOPED DRAINAGE...............................................................................................
3
A
Design Criteria and References..........................................................................................
3
BProject
Constraints..............................................................................................................
3
IVDRAINAGE
CONCEPTS..................................................................................................
4
AGeneral
Concepts................................................................................................................
4
BOn
Site Detention................................................................................................................
4
CFloodplain
Considerations
..................................................................................................
4
VDRAINAGE
DESIGN............................................................................................................
4
ASwales
.................................................................................................................................
4
BDetention
.............................................................................................................................4
CCurb
Cuts............................................................................................................................
5
DStorm
Sewer........................................................................................................................
5
VIWATER
QUALITY............................................................................................................
5
AWater
Quality Measures and Criteria.................................................................................
5
VIIEROSION
CONTROL.......................................................................................................
6
AErosion
Control Plan ...........................................................................................................
6
VIIICONCLUSIONS
.................................................................................................................6
ACompliance
with Standards................................................................................................
6
BEffectiveness
of Design......................................................................................................
6
DCREFERENCES
...................................................................................................................
6
Appendix A — Hydrology Calculations
Appendix B — Water Quality Calculations
Appendix C — Swale Design Calculations
Appendix D — Curb Cut Design Calculations
Appendix E — Erosion Control Calculations
Appendix F — Erosion Control Cost Estimate
Appendix G — Storm Sewer Design Calculations
Final Drainage Report
Fort Collins Coloradoan
May 27, 2004
Northern Engineering Services, Inc.
I hereby certify that this report (plan) for the final drainage design of Fort Collins Coloradoan
prepared by me (or under my direct supervision) for the owners thereof and meets or exceeds the
City of Fort Collins Criteria.
NUMBER
35nI
,hzAA
Mark Oberschmidt
L tered Professional Engineer
State of Colorado No. 35721
(Seal)
Pd-C I
Final Drainage Report
Fort Collins Coloradoan
May 27, 2004
I
II
Final Drainage Report
For the
Fort Collins Coloradoan
Fort Collins, Colorado
May 27, 2004
INTRODUCTION
Northern Engineering Services, Inc.
1 This Final Drainage Report summarizes the drainage design for the proposed
development of Fort Collins Coloradoan, an expansion of the existing facilities. All
calculations and design associated with this project are done in accordance with the
current City of Fort Collins Standards.
SITE LOCATION AND DESCRIPTION
A Site Location
The site is located in Northwest Quarter of Section 18, Township 7 North, Range 68
West of the 6`h Principal Meridian, City of Fort Collins, County of Latimer, State of
Colorado. More specifically, the site is located at 1212 Riverside Avenue. (See
Vicinity Map). The site is bounded by BNSF Railroad ROW on the north, Riverside
Avenue on the south and developed properties on the east and west.
B Site Description
The site slopes from southwest to northeast with about 6 feet of relief across the site.
The site encompasses approximately 2.86 acres. There are existing buildings on the
site, which will be removed. A proposed 19,600 sf building will be constructed on
the site along with revisions to the existing parking areas in Phase 1. The parking on
the east side of the site will be permanent. The parking along the west side of the
building will be temporary, as another building will be constructed there in the future
with Phase 2. This will not significantly affect the runoff quantities in the future, as it
will be replacing one impervious surface with another
2 Historically stormwater from the site leaves the site via surface flow at northeast
corner of the site. A site visit on Saturday 12/13/03 showed this to be the case. This
outfall is poorly defined and appears to be drain rather poorly. We have verbal
reports from the neighbors that water ponds up in the area on the north side of the
property to the east in heavy storms and then percolates into the soil. In addition,
runoff from the street would only enter the site if the flows in the curb and gutter
overtopped the drives at the north and south ends of the site.
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' Final Drainage Report Northern Engineering Services, Inc.
Fort Collins Coloradoan
' May 27, 2004
' 3 The developed site is subdivided in 5 sub -basins designated 1-5. Basins 1-4
contribute runoff to the northeast comer of the site. Basin 5 contributes runoff to the
street at the southeast corner of the site. Basin 5 consists of the existing half ROW
' along the frontage of the site and the landscaping areas along the frontage of the site.
Refer to Appendix A for the rational calculations. Table 1 summarizes the sub -basin
information.
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Table 1 Basin Summary
Basin
Area ac
C2
C10
C100
% Imp
1
0.70
0.69
0.69
0.87
66%
2
0.48
0.87
0.87
1.00
90%
3
1.12
0.87
0.87
1.00
89%
4
0.30
0.90
0.90
I.00
93%
5
0.72
0.83
0.83
I.00
83%
' 4 The existing site has an imperviousness of approximately 97%. Development of the
site will reduce the overall imperviousness by adding landscaping in addition to the
proposed building.
' S Basins 1-4 contribute stormwater to a proposed water quality pond in the northeast
comer of the site. Basin 1,2 and 4 will be routed to the pond via a grassed swale
' along the north property line of the site. Basin 3 is routed to the pond via the parking
lot.
III DEVELOPED DRAINAGE
A Design Criteria and References
1 Drainage criteria City of Fort Collins Rainfall IDF curves were used in conjunction
' with the Rational Method to determine peak flows at design points on the site.
B Project Constraints
1 All grading on the site will have to match the existing or proposed grades at the limits
of the site.
' 2 Detention is not required for this site. Measures to improve the water quality before it
leaves the site are required.
3 The outfall from the site is located at the northeast corner of the site. This outfall is
poorly defined east of site as noted in the site description. The percolation that occurs
Page 1
Final Drainage Report
Fort Collins Coloradoan
May 27, 2004
Northern Engineering Services, Inc.
on the property to the east will also work to remove particulates from the stormwater
runoff.
' IV DRAINAGE CONCEPTS
A General Concepts
1 Stormwater is conveyed generally via surface flows across the site to the water
quality pond.
2 Swales are provided in areas where concentrated flows occur outside of the parking
lot. A swale is provided along the north property line that will convey stormwater to
the water quality pond in the northeast corner. An existing swale along the east
' property line to convey flows from the site to the east to the northeast corner of the
Coloradoan site.
B On Site Detention
1 Detention is not required for this site.
C Floodplain Considerations
' 1 No portion of the site lies within a FEMA or City of Fort Collins delineated
floodplain. The FIRM map Community Panel Number 08100102-004C Dated March
' 18, 1996 is attached in the map pocket.
' V DRAINAGE DESIGN
A Swales
1 A proposed swale will be constructed along the north property line to convey flows
from the west parking lot and the building to the northeast corner of the site. Design
' flows are 133% of the Q 100 to the design point. Refer to Appendix C for additional
detail on the swale design.
' B Detention
1 No detention is required for this site.
1
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' Final Drainage Report Northern Engineering Services, Inc.
Fort Collins Coloradoan
May 27, 2004
' C Curb Cuts
I Two curb cuts are provided in the parking lot to convey water from the parking lot
' into the swale or the water quality pond. The cuts are sized to pass the 2-year storm
with a maximum head of 0.5 feet and the 100-year storm with a maximum head of I
foot. Thus the maximum depth of flow in the parking lot will be less than I foot.
D Storm Sewer
' 1 Storm sewer is provided at 3 locations on the site. Refer to the calculations in
Appendix G for additional detail.
a An area inlet will be constructed in the plaza area on the west side of the building.
b An area inlet will be constructed in the parking lot on the west side of the
building. Sub -basin 4 contributes to this inlet. This inlet and the storm sewer will
be removed in the future when the future building is constructed.
' c A trench drain and storm sewer will be constructed under the trash dumpster pad
on the east side of the building.
' VI WATER QUALITY
A Water Quality Measures and Criteria
' 1 Water quality criteria from the Urban Drainage and Flood Control District were used
' in designing water quality measures. Refer to Appendix B for the water quality
Calculations.
2 A water quality pond located along the north property line of the site will treat the
surface runoff before it leaves the site. The water quality pond has an available
volume of 3,896 cubic feet. The required water quality volume is approximately
' 3,890 cf.
3 A water quality outlet structure will be built into the retaining wall that defines the
' pond. A concrete pan is provided as an outlet from the water quality pond.
4 The water quality pond will allow for sediment to settle out in the pond Periodic
' maintenance of the water quality pond will be required. The owners will be
responsible for this maintenance
' 5 The water quality pond outlets to the northeast into an existing swale area that flows
to the east. It is apparent from site visits that some ponding does occur in the swale to
the east and the runoff percolates into the ground. This pending and percolations will
act as an additional water quality measure for the site.
' Page 5
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Final Drainage Report
Fort Collins Coloradoan
May 27, 2004
VII EROSION CONTROL
A Erosion Control Plan
Northern Engineering Services, Inc.
1 The erosion control measures shown on the erosion control plan will control both
wind and rainfall erosion.
2 The following temporary sediment control measures are specified to be put in place
and remain until permanent vegetation is established.
a Gravel bag dikes in swales
b Gravel inlet filters on curb cuts
c Silt fence along the east, south and north property lines
d Vehicle tracking control pads at the construction entrance
(�a 3 Permanent erosion protection will consist of buried riprap protection at the drop into
the water quality pond from the east parking lot. A construction schedule for the
riprap aprons is shown on the Grading and Erosion Control Plan. A construction
detail is provided on the detail sheet. Riprap is also provided at the outlet from the
water quality pond.
4 All disturbed areas outside of the parking lots will be seeded and or landscaped to
establish permanent ground cover. A seeding table is provided on the grading and
erosion control plan.
' VIII CONCLUSIONS
A Compliance with Standards
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1 All drainage analysis has been performed according to the City of Fort Collins
Standards.
B Effectiveness of Design
1 The design of the drainage improvements associated with the Coloradoan will
adequately treat the stormwater before it leaves the site.
IX REFERENCES
Drainage Criteria Manual, Urban Drainage and Flood Control District, Wright Water Engineers,
Inc., Denver, Colorado, Updated June 2001.
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Final Drainage Report
Fort Collins Coloradoan
May 27, 2004
Northern Engineering Services, Inc.
Erosion Control Reference Manual for Construction Sites, City of Fort Collins, Colorado,
Hydrodynamics, Inc., January 1991.
Storm Drainage Design Criteria and Construction Standards, City of Fort Collins, Colorado,
Updated April 1999.
1
Page 7
ill
W
a
5/24/2004 Northern Engineering Services Inc.
By: meo Fort Collins Coloradoan
Proj. No. COD:03-050
Flow Summary for Coloradnan.Rita Finaneinn
Design Upstream
Total
C2 C100
Tc
Tc
12 1100
Q2
Point Basins
Area
2-yr
100-yr
Q100
Developed Flows
acres
min
min
iph iph
cfs cfs
1 1,2,3,4,
2.60
0.83 1.00
11.00
10.50
2.13 7.57
4.57 19.68
2 2,
0.48
0.87 1.00
5.00
5.00
2.85 9.95
1.19 4.78
3 3,
1.12
0.87 1.00
11.00
10.50
2.13 7.57
2.07 8.48
4 4,
0.30
0.90 1.00
5.00
5.00
2.85 9.95
0.77 2.99
5 5,
0.72
0.83 1.00
11.00
11.00
2.13 7.42
1.27 5.34
COD -rational
Flow Summary
curb cut
curb cut
Sump Inlet
Street flow,
Page 1 of 7
� r M M r ® M M M M M M M M M M r M M
5/24/2004 Northern Engineering Services Inc.
COD -rational
By: meo Proj. No. COD:03-O50 Fort Collins Coloradoan
Dbasins-Summary
Sub -basin Information For Storm Sewer and Street Capacity Calculations
Area Area C2 C10 C100 Travel %%imp C2*A
Basin sf arrPa
1
30299
0.70
0.69
0.69
0.87
343
66%
0.49
2
20818
0.48
0.87
0.87
1.00
131
90%
0.42
3
48823
1.12
0.87
0.87
1.00
512
89%
0.97
4
12889
0.30
0.90
0.90
1.00
25
93%
0.27
5
31476
0.72
0.83
0.83
1.00
565
83%
0.59
Total 3.32
2.74
Average C
1 0.83
0.83
0.97
1
0.82
Weighted
Average
C
0.83
0.83
1.00
Sub-
basin
Paved/
Concrete
ac
Grass
ac
Roof ac
Total
Ac
Check
1
0.02
0.24
0.44
0.70
OK
2
0.43
0.05
0.00
0.48
OK
3
1.00
0.12
0.00
1.12
OK
4
0.28
0.02
0.00
0.30
OK
5
0.60
0.12
0.00
0.72
OK
Total 1
2.33
0.55
0.44
Impervious Area acres
acres
acres
2.77
Pervious Areal
0.55
Totall
3.32
Page 2 of 7
5/24/2004 Northern Engineering Services Inc. COD -rational
By: meo Fort Collins Coloradoan C-dbasins
Proj. No. COD:03-050
:omposite Runoff Coefficient for Sub -basins
rcentaae of land use hreakdown
Sub-
basin
Area ac
Paved/
Concrete
ac
Landscaping
ac
I Roof ac
Check
1
1 0.70
1 2.9%
34.3%
62.9%
100%
2
1 0.48
89.6%
10.41
0.0%
l00%
3
1.12
89.3%
10.7%
0.0%
100%
4
0.30
93.3%
6.7%j
0.0%
100%
5
0.72
83 . 3F61
16.7%1
0.0°%
100°%
Land use Breakdown
Sub-
basin
Area acl
Paved/
Concrete
ac
Landscaping
ac
I Roof ac
Total
Area ac
1
1 0.70
0.02
0.24
0.44
0.70
2
0.48
0.43
0.05
0.00
0.48
3
1.12
1.00
0.12
0.00
1.12
4
0.30
0.28
0.02
0.00
0.30
5
0.72
0.60
0.12
0.00
0.72
Determine Runoff Coefficient for
2
yr storm
Area*C2
Sub-
basin
C
Paved/
Concrete
Landscaping
Roof
Total
A*C2
0.95
0.20
0.95
1
0.69
0.02
0.05
0.42
0.49
2
0.87
0.41
0.01
0.00
0.42
3
0.87
0.95
0.02
0.00
0.97
4
0.90
0.27
0.00
0.00
0.27
5
0.83
0.57
0.02
0.00
0.59
Page 3 of 7
5/24/2004 Northern Engineering Services Inc.
By: meo Fort Collins Coloradoan
Proj. No. COD:03-O50
Determine Percent Impervious for each Basin
Area*Imnerviou.cnPsa
Sub-
basin
%impery
Paved/
Concrete
I Landscaping
Roof
Total
A*I
100°s
0%i
100%
1
66%
0.02
1 0.00
0.44
0.46
2
90%1
0.43
1 0.00
0.00
0.43
3
89%
1.00
0.00
0.00
1.M
4
93%
0.28
0.005
83%
0.60
0.00
0.00
0.
Determine Site Imperviousness
Sub -basins 1 and 2 only
Imperviousness 75.42%;
Determine Existing Imperviousness for site
Site Area 124SAS of - 0
Paved/
Sub-
Concrete
Landscaping
I
basin
%impery
ac
ac
Roof ac
Total
10016
096
100%
Ex Site
96.9%
2.05
0.09
0.72
2.86
COD -rational
C-dbasins
Determine Contributing area and peak flow to swale along east property
line from existina site
EPnaaved/
ete
Landscaping
I
Check
Area ac
C2
ac
Roof ac
Area ac
0.95 0.20 0.95
0.40 0.86 0.24 0.04 0.12 0.40
Tc min
I2 iph
1100 iph
Q2 cfs
C100
Q100 cfs
5.00
1 2.85
1 9.95
0.98
1.00
3.98
Page 4 of 7
5/24/2004 Northern Engineering Services Inc.
By: meo Fort Collins Coloradoan
Proj. No. COD:03-050
Design Point Summary
Composite Runoff
Coefficients
COD -rational
Dpointsummary
DP
Contributing
Sub -basins
Area
ac
C2
C10
I C100
°, Imp
1
1,2,3,4,
2.60
0.83
0.83
1 1.00
1 83.5%
2
2,
0.48
0.87
0.87
1.00
1 89.6°s
3
3,
1.12
0.87
0.87
1.00
89.3%
4
4,
0.30
0.90
0.90
1.00
93.3%
5
5,
0.72
0.83
0.63
1.00
83.3%
Page 5 of 7
11M M M = = = = = = M = = M r r
5/24/2004 Northern Engineering Services Inc. COD -rational
By: meo Fort Collins Coloradoan DQ-basin-Major
Proj. No. COD:03-050
MAJOR STORM - 100-YEAR EVENT
Fort Collins
Colorado
Overland
Flow Time of Concentration:
Intensity, I From Figure 3-1
Ti = (0.395 `( 1 . I -CCf)'L ^ 0.5)/5 ^ 0.33
Gutter/Swal Flow Time of Concentration:
Rational Equation: Q = CiA (Equation
RO-1)
Tt = L
/ GOV
Velocity (Gutter Flow), V = 20 5'
T, = T,
+ Tt (Equation RO-2)
Velocity (Swale Flow), V = 15
S" J
Note:
Actual Tc rounded to the nearest 0.5 minutes
Pipe C factor = I .48GAR213/n
C5 assumes all overland flow Is grass unless otherwise noted
Sub-basm Info
Slopes for Travel times are average slopes over the travel distance
Overland Flow Gutter Flow Swale Flow
Tc
Sub- Area
Basin acres
flows
C 100
CCf
Length,
L
(ft)
Slope,
S
M
T.
(min)
Length,
L
00
Slope,
S
M
Vel,
V
(ft/s)
Tt
(min)
Length,
L
(ft)
Slope,
S
M)
Vel,
V
(ft/s)
Te
(min)
Comp.
T�
(min)
Travel
Length
(ft)
U180+
10
Actual
T�
(min)
Intensity, I
(in/hr)
Flow,
(cis)Developed
1
2
3
4
5
Total
Determine
0.70
0.48
1.12
0.30
0.72
3.32
Tc
0.e7
1.00
1.00
l.oa
1.00
0.00
to Pond
1.00
1.00
0.25
0.15
0.15
0.15
from
41
131
15
10
11
11
site
1.00
2.00
2.00
2.00
2.00
2.00
1.2
1.7
4.8
4.4
4.6
4.6
0
O
497
15
554
554
0.00
0.50
0.50
0.50
0.50
0.50
0.00
1.41
1.41
1.41
1.41
1.41
0.0
0.0
5.9
0.2
6.5
6.5
302
0
0
0
0
0
0.50
1.00
0.00
0.00
0.00
0.00
1.06
1.50
0.00
0.00
0.00
0.00
4.7
0.0
0.0
0.0
0.0
0.0
5.9
5.0
10.6
5.0
I.1
11.1
343
131
512
25
565
565
11.91
6.0
9.31
5.64
10.73
5.0
9.95
4.7E
12.84
10.5
7. s7
8.4E
10.14
5.0
9.95
2.99
13.14
I1.0
7.42
5.34
13.14
11.0
7.4z
o.00
1
1
1-4
1-4
North
South
I.00
0.25
131
15
2.00
2.00
1.7
4.8 1497
0
0.50
0,50
1.41
1.41
0.0
5.9 I0
448
1
0.50
0.50 1
.06
1.06 1
7.0
0.0 1
8.7
10.6
579
13.22
8.5
NA
NA
512 1
12.541
10.5 INA
IMA
Conclude: TC to pond fro 10.50 minutes
Page 6 of 7
M = IM M =1
5/24/2004 Northern Engineering Services Inc.
By: meo Fort Collins Coloradoan
Proj. No. COD:03-050
MINOR STORM - 2-YEAR EVENT
Fort CollinsColorado
Overland Flow. Time of Concentration Intensity, I From Figure 3-1
Ti = (0.395"( 1 . I-CCf)'L^ 0.5)/5 ^ 0.33 Rational Equation: Q = CiA (Equation RO-1)
Guttfr/Swate Flow Time of Concentration
Tt = L / GOV Velocity (Gutter Flow), V = 20 5"'
T, = T, + Tt (Equation RO-2) Velocity (Swale Flow), V = 15 5"'
Note: Actual Tc rounded to the nearest 0.5 minutes
C5 assumes all overland flow is grass unless otherwise noted
Slopes for Travel times are avern,, ch,n« .,, Hk_ Y_, i
Sub -brim Info
Overland Flow
Gutter Flow
Swale Flow
T
5ub-
Length,
51ope,
Length,
Slope,
Vel,
Length,
Slope,
Vel,
Comp.
Travel
Area
lBa5m acresFC2
L(it)
L
5
T.
encjth
CCf
(ft)
M
(min)
(t)
M
(ft/5)
(min)
(t)
I%)
(ft/5)
(min)
(min)
(it)
Developed flows
0.69
0.95
41
1.0
1.8
0.0
0.0
0.00
0.0
302.0
0.5
1.06
4.7
6.5
343
0.87
0.95
131
2.0
2.5
0.0
0.5
1.41
0.0
O.O
I.0
I.50
0.0
5.0
131
0.87
0.20
15
2.0
5.1
497.0
0.5
1.41
5.9
0.0
0.0
0.00
N/A
10.9
512
0.90
0.1510
2.00
4.4
I5
0.50
I.41
0.2
O
O.0
0.00
N/A
5.0
25
0.83
0.15 1
11 1
2.00
4.6
554
0.50
1.41
6.5
0
0.0
0.00
N/A
I.I
Determine To to Pond
from
site
565
COD -rational
Dq-basin-Minor
U180+
10
Actual
T�
(min)
Intensity,
I
(in/hr)
Flow,
(cf5)
11.31
6.5
2.60
1.26
10.73
5.0
2.85
1.19
12.84
11.11
2.13
2.17
10.14
5.0
2.85
0.77
13.14
I.0
2.13
1.27
1
i
1-4
1-4
North
ISouthl
0.95
0.20
131
115
2.00
1 2.00
2.5
1 5.1
0
457
0.50
0.50
1.41
1 1.41
0.0
15.9
448
O
0.50
0.50
1.06
1 1.06
7.0
1 0.0
9.5
1 10.9
579 13.22 9.5
512
1 12.84
1 11.0
conclude: Tc to pond froll.00 minutes
Page 7 of 7
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By: meo
Proj. No. COD:03-050
Reference
Northern Engineering Services Inc.
Coloradoan
Urban Storm Drainage Criteria Manual, Volume 3 - Best Management Practices, Urban Drainage
and Flood Control District, September 1999.
Project I I Location
joloradoan Expansion IFort Collins, CO
REQUIRED STORAGE & OUTLET WORKS:
BASIN AREA = 2.170 <--INPUT from impervious calcs
BASIN IMPERVIOUSNESS PERCENT = 83.46 <-- INPUT from impervious calcs
BASIN IMPERVIOUSNESS RATIO = <- CALCULATED
WQCV (watershed inches) _ <-- CALCULATED from Figure EDB-2
'
WQCV (ac-ft) _ <— CALCULATED from UDFCD DCM V.3 Section 6.5
10cf
WQ Depth (ft) _'-` 2.730'" <-- INPUT from stage -storage table
AREA REQUIRED PER ROW, a (in2)_ <-- CALCULATED from Figure EDB-3
1
1
1
1
CIRCULAR PERFORATION SIZING
dia (in) _
5/16-.:
. <-- INPUT from Figure 5
s. (in) =
2
<— INPUT from Figure 5
n =
2 '.
<-- INPUT from Figure 5
t (in) _.
3/$ ;.a;
<-- INPUT from Figure 5
number of rows =
<— CALCULATED from WQ Depth, row spacing, and
channel thickness
round to lowest whole -number =
total outlet area (in2)_
INPUT from above cell
CALCULATED from total number of wholes
TRASH RACK DESIGN
Trash Rack Open Area Ratio =�fsF <-- CALCULATED from Figure 7
Required Trash Rack Open Area (inZ) ,l <-- CALCULATED from UDFCD DCM V.3 Section 6.6
Wconc (In) = 3 <-- INPUT from Table 6a-1
Wopentng (in) = 9 —INPUT from Figure 4
DON'T FORGET WELL -SCREEN * N/A <-- INPUT from Table 6a-2
WQCV
EDB
' Page 1 of 3
5/25/2004
By: meo
Proj. No. COD:03-050
Determine Volume for WQ pond
Volume = 1/3'd"(A+B+sgrt(A"B))
Northern Engineering Services Inc.
Fort Collins Coloradoan
Overflow
Pond
First Even
Top of Pond
Weir
Bottom It
Increment ft
Contour ft
Elevation ft
elevation It
4944.30
0.50
4945.00
494746F
4946.50
Stage ft
Elev (E) ft
Area (A) A
Volume
(VI) cf
Cum
Volume
(Vc) of
Cum
Volume
(Vc) AF
0.00
4944.30
0
0
0
0.00
0.70
4945.00
1113
260-
260
T 1
1.70
4946.00
2850
1915
2174
0.05
2.20
4946.501
3984
1701
3875
0.09
Determine Required WSEL for WQ Volume
Required
Volume cf
WSEL ft
Depth ft
3319
4946,34
2.04
Volume cf
Stage ft
3875
2.20
3318.98
2.04
2174 1
1.70
WSEL = 4946.34 ft
Concluded: Water Quality pond is adequate
WQCV
Pond Volume
Page 2 of 3
5/25/2004 Northern Engineering Services Inc.
By: meo Coloradoan
Proj. No. COD:03-050
Size overflow weir from WQ pond
Criteria - minimize head over weir since the length of wall required to obtain the volume will be
extensive
Design Q
Maximum
C
Req'd Design
Actual
M100
Head (H)
Length ft Length
Head ft
ft
(Lr) (Ld)ft
4.57
0.2
2.6
19.67 20.00
- 0.20
Conclude:
Design the weir to split the flow along the south and east retaining walls
Elevation of overflow weir is 4946.50 ft
Top of Wall is 4947.04 ft
WQCV
overflow weir
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2/9/2004 Northern Engineering Services Inc. COD -Swale
By: meo Fort Collins Coloradoan Channel
Proj. No. COD:03-050
Design of Triangular of Trapezoidal Swale
Swale Description Swale along Railroad Legend
Input
Channel Configuration Trapezoidal Calculation
Channel Lining Grass Error Check
Design Storm 100 year Title
Q Design Storm (Qds) 21.57 cfs
Design Q = Qds* 1.33 28.69 cfs
Da Db Dc Sc n W I
ft ft ft ft/ft ft ft
5.25 5.25 1.75 0.0040 0.032 2.00 0.25
0.33 Left Bank Slope 3.0 :1 Side Slope
0.33 Right Bank Slope 3.0 :1 Side Slope
Dc ft Top Area sf Perim ft R 2/3 Se 1/2 Q cfs V ft/sec
Width ft (A/P) ft
1.75 1 12.50 1 12.69 1 13.07 1 0.98 1 0.06321 36.54 1 2.88
Formula Q = 1.486*A*R�2/3*S�0.5/n
Conclude:
Swale is adequate for flows
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5/24/2004 Northern Engineering Services Inc. COD -curb cuts
By: meo Coloradoan Broadcrested Weir
Proj. No. COD:03-050
Determine Required width of curb cut to pass 02 @ Maximum Head - only required to handle
first flush (use the Q2) to water quality pond- for water quality purpose
Maximum
C
Req'd Design Actual
Head (H)
Width ft Width Head ft
I
EDesign
Q2 cfs
ft
(Lr) (Ld)ft
h%=2.07
0:50
- $.00
196 6.00 0.24
; 1:I`9'
0.50
3.00
,= 1';17 -'2.00 034
Formula : Q = CLH^312
L = Q/CHA3n
H = (Q/CL)A213
Determine required head for Q100- max head = 12" - max depth in parking lot allowed
Maximum
C
1
Design
Actual
Head (H)
Width
Head ft
Design Point
0100 cfs
ft
(Ld)ft
3
d ;,8,48
100
3.00'
,„„` +
t ',
6.00
mot, 0,61
2
4: �
1.00
3.00
Conclude: width is adequate to pass initial flows to water quality pond. There will be some
overflow into the swale along the east property line @ DP 1 during the 100-yr event. Flow
depths in the parking lot will be <= 1.0 foot at each location.
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RAINFALL PERFORMANCE STANDARD EVALUATION
STANDARD FORM A
PROJECT: Fort Collins Coloradoan MAJOR BASIN: All Areas
CALCULATED BY: MEO TOTAL BASIN AREA (Ai,) : 3.380 acres
DATE: January 2 1, 2004
DEVELOPED
5UB-BA5(N
ERODISILITY
ZONE
A,h
(acres)
L„r
(ft)
.,�, x
A�>
5,b
(%)
A,6 x 5,6
Le
(ft)
Sy P5
(%). (%j
l
MODERATE
2.150
574.
1234.1
2.00
4.30
2
MODERATE
0.490
12C
61.7
2.00
0.98
3
MODERATE
0,740
4,59
3C.1.9
1.00
0.74
TOTAL
3.380
1G57.7
6.02
490
1.78 78.2-
' EQUATIONS:
Lb l
(Lsb X Lsb l / Sb (Ssb X L'sb /
1 —
Ab `4b
' PS (during construction) = 78.2 (From Table 5.1)
PS(after constru t1 n) 92.O Ps^
, / 0.85
EFFECTIVENESS CALCULATIONS
5TANDARD FORM B
i e�wwi: i ur" wum5 i uioraaoan MAJUK BASIN: All Areas I
CALCULATED BY: meo TOTAL BASIN AREA (Al,) : 3.350 acres
DATE: January 21, 2004 CONSTRUCTION PROCE55: Dunna
Sediment Basin / Trap
1 .00
1 0.50
lat all pond outlet structures and above -ground inlets
Gravel Bag Barrier
1,00
1 0.80
Jim Swale along north property line
Straw Bales
1.00
1 0.80
Inot applicable
Asphalt / Concrete Pavement
0.01
1 1.00
jall roads, parking lots, walks, etc.
Erosion Control Mats / Blankets
0.10
1.00
not applicable
5ilt Fence Barrier
1.00
0.50 jalong
north and east property line
Temporary Vegetation / Cover Crops
0.45
1.00 inot
applicable
Hydraulic Mulch @ 2 Tons / Acre
0.10
I .00 Inot
applicable
Hay or Straw Dry Mulch (From Table 5.2)
0.17
1.00 Inot
applicable
All Areas 1 75.2
> 78.
PLAN INTENT: see "Grading and Erosion
3.380 Control Plan" from the set: Utility Plant for
Fort Collins Coloradoan
Roads:
Impervious 3.380 1 Walks: all pervious areas have been grouped together
Parking:
Pervious 1 0.000
C"' = 0.01
P, = 0.20
EFF = 59.8%
construction erosion control measures
EQUATIONS:
(Ai x Ci
C. = A P. =P, xP,xP,... EFF=[1—(CxP)]x100
b
2/9/2004 Northern Engineering Services Inc. COD-EFF-Calcs
By: meo Fort Collins Coloradoan Form B (after)
Proj. No. COD:03-050
EFFECTIVENE55 CALCULATIONS
STANDARD FORM B
T: Fort Collins Coloradoan MAJOR BASIN: All Areas
ATED BY: meo TOTAL BASIN AREA (A0 : 3.380 acres
nuary 2 1, 2004 CONSTRUCTION PROCE55: After
F
I .00 all roads, parking btswalk.etc.
Concrete Pavement
0.01
ed Native Grasses (riq., 5.1)
0.34
I .00
1n Swale abng north propertyy line
Sod Grass
0.01
I .W
all on -site Iandscapmg
MAJOR
Y'5
.
BA51N
{%)
'SUB BASIN
(acI'r;
PLAN INTLNTL see "Gradingand Erosion
All Arcas
92.0
3.380
Control Plan' from the set: Utility Plans for
Fort Collins Coloradoan
Roads:
Impervious
3,360
Walks: all pervious areas have been grouped together
Parkmg:
Pervious
0.000
Native Grass: 0.300 acres in along north property line and WO pond
Sod Grass: 0.071 acres of permanent sod landscaping
C , = 0.01
Pa= 1.00
EFF = 99.09E
EQUATIONS:
�(A,xC )
C.,= P,,=PxP=xP3... EFF=[1—(CxP)x100]
Ae
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2/9/2004 Northern Engineering Services Inc. COD -Erosion Costs
By: meo Fort Collins Coloradoan Sheetl
Proj. No. COD:03-050
Fort Colhn5 Coloradoan
Ero5lon Control Cost E5tIRIatC
Project Number: COD:03-050
Location:
Fort Collins, CO
Date: January 21 ,2004
Total Acre:
3.35
Estimated
Unit
Total
EP05ION CONTROL MEA5URE
Units Quantity
Price
Price
Gravel Bag Inlet Filters
each 4
$75.00
$300.00
5ilt Fencing
L.F. 900
$2.50
$2,250.00
Gravel Bag 5ediment Traps
each 2
$100.00
$200.00
Gravel Bag Dikes
each 4
$75.00
$300.00
Vehicle Tracking Control Pads
each 2
$200.00
$400.00
TOTAL =
$3, 450.00
AMOUNT OF 5ECURITY = 1.5 x
$3,450.00 =
TOTAL =
$5,175.00
-OR-
005T TO VEGETATE: TOTAL ACRE5 x
($G55/acre) x 1.5 =
TOTAL =
$3,320.85
(WHICHEVER 15 GREATER)
REQUIRED AMOUNT OF 5ECURITY =
$5, /75.00
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5/25/2004 Northern Engineering Services Inc.
By: meo Coloradoan
Proj. No. COD:03-050
Determine Capacity of Pin Wheel Drain and storm sewer under Building
Contributing
area sf
Contributing
area ac
C
Tc min
I 1100 iph
0100 cfs
I-
140010.031
0.951
51
9.951
0.38
Grate
Type
Area sq in
Free
Free
Max
Max
Allowable
Drain
drain area
Capacity
allowable
Capacity
area %
sf
cfs
flow
cfs
[13-1/2"
(1)
depth (d)
ft
Pinwheel
182.25
0.169
0.21
0.84
0.5
0.75
COD -area inlet
Al
Max Capacity based on 0.8 ft head over inlet (D)
Flow in per sf Open Area 3.95 cfs per ft of head over inlet - Figure 5-3 Capacity if Grated inlet
in sump
Allowable capacity based 0.5 ft head over inlet (d)
Flow in per sf Open Area 3.50 cfs per ft of head over inlet - Figure 5-3 Capacity if Grated inlet
in sump
Conclude: Sidewalk to southwest will overtop with flow depth of more than 0.10 feet so we can be fairly
sure that icing will not be a problem
Notes
1 - Free area percentage from the supplier
2 - Capacity
Pipe Capacity
Pipe Diam ft
Pipe Area sf
Pipe
Perim ft
Hyd Rad
ft
n
C
Slope ft/ft
Capacity
cfs
0,671
0.351
2.101
0.16751
13.26642
0.005
0.94
Conclude: Pipe and Inlet are adequate
Page 1 of 2
5/25/2004 Northern Engineering Services Inc.
By: meo Coloradoan
Proj. No. COD:03-050
Determine Capacity of area inlet and storm sewer in west parking lot
Basin I Q100 cfs
41 2.99'
Grate
Type
Free
Max
drain area
Capacity
sf(1)
cfs
R-3340
B
1.30
5.14
Max Capacity based on E
Flow in per sf Open Area ll—_
Conclude: Inlet is adequate
Notes
1 - Free drain area from supplier
Pipe Capacity
head over inlet (D)
s per ft of head over inlet -
Pipe Diam ft
Pipe Area sf
Pipe
Perim ft
Hyd Rad
ft
n
C
Slope ft/ft
Capacity
cfs
1.0
` k0;79
;^ 314
0,251
0.013
,35;5Zs05
Conclude: Inlet and Pipe adequate. Pipe will flow under pressure during the 100-year event
COD -area inlet
A2
inlet
Page 2 of 2
49 47 46 p5
- - -
1 47 � 46
El
A
�
Z / 7 cues cur 1' clu6e cur
TRENCH DRAIN\ J
/ / s \ •.•\ 4(�\ .. "AND 6" HOPE /
jb STORM DRAIN 3
8" HOPE
\\ - / 1.01.12
\ i
1.0 D.4B STORM \ CIAWATE UALITY POND
/ DRAIN / EO'D VOL M - 3871 CF
AVAI BLE
VOL M = 3875 CF
- - IN LUDES V LU E IN SWALE
n w T P OF POND TOP WAL - 4947.04 FT
OVE FLOW 4946.5 FT /
INV UT = 4944.30
11 CURB
CHASE
12" HDPE
STORM
TRAIN
/ /
I
�552 1 /
IMF Miss GES 001 MEN
gig
5p t
4 49 \ \
2' CONCRETE TRICKLE PAN' \ I
/
\ I \
Nov
52 ♦ G, i '� 51 49 _
/ _
5 14
_ - 5 '
-- -4950- - - 1.0 D.72 z
RIVERSIDE AVENUE----_495D-_
LEGEND/
ul"NO STORM S INLU
-5020 m"NO CCNIWa
-..-. -...- ECSBNQ RnuNE
PRNmT KDMNDN.,
sim midiiiiiiii PROPOSED afR mumN
xw ®xm
NIX
ImVR C V4E
1C0-YFA9 C VI LE
L' DESIGN FORT
PBOPER BQUNUAl
P Nmm 2PAN
DUSBIC CCNoUR5
PROPOSE➢ CURB AND :UTTR
Flow Summary
Coloradoan Site Expansion
Design
Point
Basins
Area
acres
C2
C100
Tc Tyr
min
Tc
100yr
min
12
iph
1100
iph
Q2
efs
Q100
a1's
Notes
Developed Flows
1
1,2,3,4,
260
0.83
1.00
11.00
10.50
2.13
7.57
4.57
19.68
WQ pond
2_
2,
0.48
0.87
1.00
5.00
50OT2.-851
9.95
1 1.19
1 4.78
curb cut
3
31
2
0.87
1.00
11.00
10.50
1 2.13
17.57
2.07
8.48
curb cut
4
4
0.30
0.90
1.00
5.00
5.00
2.85
9.95'
0.77
2 99
Sump Inlet
5
51
0.72
0.83
1.00
1 1.00
11.00
2.13
7.42
1.27
1 5.34
Street flows
20 0 20 W Ai 1,.L
IN m I
1 imh . N IL
City of Fort Collins, Colorado
UTILITY PLAN APPROVAL
CHECKED Rt;Y
CHECKED 6r:�
CHECKED W: �-
CHECKED Bn�
6
CHECKED BT: -��