HomeMy WebLinkAboutDrainage Reports - 03/22/1996Final Drainage Report
for
Landings Office Park P.U.D.
City of Fort Collins, Colorado
October 27, 1995
Prepared For:
Lagunitas Company
Prepared By:
Northern Engineering Services, Inc:
420 South Howes, Suite 202
Fort Collins, Colorado 80521
(970)221-4158
Fax (970)221-4159
Project Number: 9516.00
Fourth Final Submittal
Northern Engineering Services, Inc.
October 27, 1995
City of Fort Collins
Stormwater Utility
235 Mathews
Fort Collins, Colorado 80522
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RE: Landings Office Park P.U.D.
' Fort Collins, Colorado
Project Number: 9516.00
Dear Staff:
Northern Engineering is pleased to re -submit this Final Drainage Report for the
Landings Office Park P.U.D. for your review. We have addressed the comments
contained on the Project Comment Sheet dated October 24, 1995.
' This report was prepared in compliance with technical criteria set forth in the City
of Fort Collins Storm Drainage Design Criteria and Construction Standards manual.
If you should have any questions or comments as you review this revised report,
' please feel free to contact me at your convenience.
' Sincerely,
NORTHERN ENGINEERII INC.
r ..8 0• Hy •.'gam
Mary B. Wohnrade, P.E�• 30325
420 S. Howes, Suite 202 • Fort Collins, Colorado 80521 • (970) 221-4158 • Fax (970) 221-4159
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' Final Drainage Report
for
Landings Office Park P.U.D.
I. GENERAL LOCATION SITE DESCRIPTION
General Location
This report summarizes the results of a storm drainage investigation for the
proposed Landings Office Park P.U.D. site. The project is located in the NW Quarter
' of Section 36, Township 7 North, Range 69 West of the 6th Principal Meridian in Fort
Collins, Colorado. The project is bounded by Horsetooth Road to the north,
Boardwalk Drive on the south, Landings Drive on the east, and JFK Parkway to the
west. (See Vicinity Map).
' Site Description
The 3.19 acre site is located in southeast Fort Collins, is currently residential
and vegetated with native grasses and weeds. The surrounding land use patterns are
residential (The Landings P.U.D. and High Point P.U.D.) to the east, commercial to the
south (U.S. Post Office) and west (ShopKo P.U.D.) and currently undeveloped land to
' the north. The site is in the vicinity of the Larimer County Canal No.2 to the north,
south and east.
' II. HISTORIC DRAINAGE
Major Basin Description
' The project is located in the McClellands/Mail Creek Drainage Basin. The
proposed site drains to the Larimer County Canal No. 2 according to the °Final
Drainage Report for Heart Special Improvement District', dated December, 1984,
' revised January, 1985 by Engineering Professionals, Inc.. The report gives a
maximum allowable release rate for the site of 0.87 cfs/acre.
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Landings Office Park P.U.D. October 27, 1995
Final Drainage Report Page 2
' II. HISTORIC DRAINAGE. con't
' Historic Drainage Patterns
A ridge traversing east -west divides the site, with the majority of stormwater
runoff flowing to the south-southeast to Boardwalk Drive. The historic drainage
pattern of the site is from, north to south-southeast and, south to northeast (as
predicated by the ridge) by overland flow at slopes ranging from 3.2% to 4.9%. There
is no off -site runoff entering the site due to the ridge and street boundaries.
There is an existing 4' Type R Curb Inlet located at the northwest comer of
Boardwalk and Landings Drives. A 15" diameter pipe extends from the inlet,
southeast under Boardwalk and daylights into a vacant lot east of the U.S. Post Office.
A 15' Type R Curb Inlet is located at the northeast corner of JFK Parkway and
Boardwalk. Stormwater flows from this inlet west, under JFK Parkway to another 15'
Curb Inlet and continues north to the East Detention Pond of ShopKo P.U.D..
There are no existing drainage structures or irrigation laterals on the site.
III. DEVELOPED DRAINAGE
Developed Conditions
The proposed development of the site includes 8 commercial buildings with a
central parking area and includes all utilities. Three (3) drive entrances will serve the
site off of JFK Parkway, Boardwalk Drive and Landings Drive.
Design Criteria and References
Drainage criteria outlined in both the City of Fort Collins Storm Drainage Design
Criteria Manual.(SDDCM) and Storm Drainage Criteria Manual by the Urban Drainage
and Flood Control District have been used for this Preliminary Drainage Study. The
Final Drainage Report for Heart Special Improvement District" by Engineering
Professionals, Inc. has also been referenced.
' Landings Office Park P.U.D. October 27, 1995
Final Drainage Report Page 3
' III. DEVELOPED DRAINAGE con't
Hydrologic Criteria
The Rational Method was used to estimate peak stormwater runoff from the
proposed development site. An initial 2-year design storm and major 100-year design
storm was used to evaluate the proposed drainage system. The culvert under the
Boardwalk drive entrance has been sized for the 10-year storm. Rainfall intensity data
1 for the Rational Method was taken from Figure 3-1 of SDDCM.
Hydraulic Criteria
The City of Fort Collins Storm Drainage Design Criteria has been used for all
hydraulic calculations.
' General Drainage Concept
The majority of on -site developed stormwater runoff will be conveyed through
the Landings Office Park site by overland flow, vertical curb and gutter, sidewalk
chases and a drainage culvert to two (2) proposed detention facilities located in the
northeast and southeast corners of the site. From. the detention facilities, stormwater
will be conveyed to the Larimer County #2 Canal via either off -site swale or curb and
gutter.
Specific Details
iAccording to the Heart Special Improvement District Drainage Report, a total of
98 acres above the Larimer Canal drains to the irrigation/stormwater ditch. The staff
' at the City of Fort Collins Stormwater Utility Department recommended the canal
convey a total discharge of 240 cfs, 155 cfs of irrigation flow and 85 cfs of stormwater
flow. The 0.87 cfs/acre maximum release rate was calculated using these factors (85
cfs/ 98acres). The Landings site is part of the 98 acres tributary to the Larimer Canal
and therefore would require detention of stormwater to the required rates. Due to the
topography of the site, it will not be feasible to route runoff from the entire site and
adjacent streets to detention facilities to be released at the allowable rate of 0.87
cfs/acre.
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Landings Office Park P.U.D.
Final Drainage Report
Specific Details, con't
October 27, 1995
Page 4
The release rate specified by the Heart Special Improvement District report is
not the only criteria to be met in discharging stormwater from the site, there are two
additional requirements.
First, the release rate from Basins' D2 (undetained) and D4 (detained)
combined should not exceed 2.75 cfs at an existing inlet located approximately 170
feet north of the site in the west flowline of Landings Drive. Shear Engineering
' calculated this (historic) flow as part of the Jetty P.U.D. in 1986. The same site was
developed as High Pointe P.U.D. in 1989 (See excerpts from High Pointe Drainage
Report in Appendix). The developed 100-year flow from these basins (D2 and D4) at
Design Point D10 is 3.1 cfs which exceeds 2.75 cfs but is not excessive and is
anticipated to have minimal impact on street and inlet capacities. It is not possible to
capture any additional runoff from these basins, in addition, a transverse inlet is
' proposed across the drive entrance off of Landings Drive to intercept any last runoff
prior to leaving the site.
Secondly, the release rate from Basin D3 must not exceed 2.76 cfs at an
existing 15' curb inlet located at the northeast comer of JFK Parkway and Boardwalk
' Drive. The inlet was installed as part of the ShopKo P.U.D. (JFK Parkway
Improvements) and designed by TST, Inc, Consulting Engineers in 1993 (See letter
dated August 10, 1993 in Appendix). Runoff entering the inlet is conveyed to the East
Detention Pond of ShopKo and eventually released to the Larimer County #2 Canal.
The developed 100-year flow calculated at Design Point D3 from the Landings site is
2.3 cfs and therefore is below the anticipated flow calculated by TST. The existing 15'
curb inlet is capable of intercepting the anticipated 100-yr flow of 2.3 cfs.
The Landings site is divided into three release points discharging stormwater
into three separate directions all of which are conveyed to the Larimer County #2
Canal. As previously mentioned, runoff from Basin D3 will be conveyed to the
ShopKo P.U.D. due to the presence of an existing curb inlet. Runoff from Basins' D2
' and D4 is conveyed north down Landings Drive to an existing curb inlet and then
through Pond 'A' of High Pointe P.U.D. to the Larimer #2 Canal. Runoff from Basins'
D1, D5, D7,D8 and D9 will be routed to the proposed Detention Pond D1 located in
' the southeast corner of the site. The pond will release into an existing 4' curb inlet
located at the northwest comer of Landings and
Landings Office Park P.U.D. October 27, 1995
Final Drainage Report Page 5
Specific Details. con't
Boardwalk. From the inlet stormwater will be conveyed through an existing 15 inch
RCP which daylights onto a vacant City of Fort Collins S.I.D. property at the southeast
corner of the intersection. Stormwater will be conveyed from the pipe outlet to the
Larimer #2 Canal via an open grass -lined swale. This channel will require a 10'
drainage easement through the City of Fort Collins S.I.D. property. The size of the
orifice controlling the release from Pond D1 has arbitrarily been set at 3-inch diameter
which allows for a minimum release rate at a minimum practical diameter to minimize
' clogging. With stormwater being detained, undetained and discharged in three
separate directions, summarizing a single release rate from the site is difficult. To
summarize 100-yr flow rates in each direction, 2.3 cfs goes west to ShopKo to be
' detained, 3.67 cfs goes south to the off -site swale and 2.19 cfs goes north to High
Pointe P.U.D.. It is important to note that the majority of the area contributing to
undetained flows are the adjacent streets. Every attempt has been made to capture
and detain stormwater from the site.
Runoff from Basin D6 will be undetained and will collect at the existing 4' curb
inlet located at the northwest corner of Landings and Boardwalk. From the inlet
stormwater will be routed through the same conveyance elements as the release from
Pond D1 to the Larimer #2 Canal. We attempted to direct this water to Pond D1
through the existing 4' curb inlet but due to the anticipated 100-year water surface
elevation of 5042.38 in the pond, and the fact that the pond and street would then be
' hydraulically connected, water from the pond would back up into Landings Drive due
to the existing flowline elevation of 5041.82 at the inlet.
Detention Pond D4, located in the northeast corner of the site, will detain
developed runoff from Basin D4 and will have a maximum release rate of 0.289 cfs
through a 3" diameter control orifice. This parking lot detention pond will discharge
into the flowline of Landings Drive, combine with flow from Basin D2 and continue
north down Landings to an existing curb inlet and eventually into the Larimer County
Canal #2.
IV. EROSION CONTROL
Temporary sediment control will be provided at the inlet end of both the
detention pond outlets and silt fence will erected around the perimeter of the site.
Permanent vegetative erosion control will be used in conjunction with
landscaping in areas surrounding the building and parking areas and, in the parking
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Landings Office Park P.U.D. October 27, 1995
Final Drainage Report Page 6
islands. The proposed grassed detention facility and off -site swale shall be covered
with topsoil and revegetated with grass according to criteria given in Section 7 of the
City of Fort Collins Erosion Control Reference Manual. Permanent Type L riprap will
be provided at the outlet of the existing 15" RCP on the city's S.I.D. property and
riprap will be placed at the outlets of all storm sewers.
' V. CONCLUSIONS
Comoliance with Standards
All drainage analyses have been performed according to the City of Fort Collins
Storm Drainage Design Criteria Manual (SDDCM) and the Urban Drainage and Flood
Control District's Drainage Criteria Manual. A variance is requested for the required
0.87 cfs/acre maximum release rate as stated in the "Final Drainage Report for Heart
Special Improvement District". The total area of the site, out to the centerline of
adjacent streets, is 4.079 acres which would translate into an allowable release rate of
0.87 cfs/acre x 4.079 acres = 3.55 cfs.. Since runoff from Basin D3 is detained
through ShopKo, this leaves a total release rate of 3.67 + 2.19 cfs = 5.86 cfs from the
remainder of the site. There will be some attenuation in the off -site swale and
possibly Detention Pond "A" at High Pointe P.U.D.. The request for a variance is due
to the inability to detain all developed runoff from the site due to topography.
A variance is also requested for a maximum depth of parking lot detention of
1.66' in the northeast corner of Detention Pond D4. As requested by Stormwater
Utility, signage has been required for this area, in addition the total area effected by
this depth is a maximum of 2 parking stalls. The drainage certification for this project
will be done building by building.
Summary of Drainage Concept
Measures have been taken to ensure adequate drainage facilities have been
provided with attention given to water quality and, public health and safety of persons
using the Landings Office Park facilities. The hydraulic and hydrologic analyses
conducted for this study have been performed in a manner consistent with standard
' practice and principles of civil engineering. All known available information has been
referenced where applicable to this study.
Impacts to the Larimer County #2 Canal in relation to existing conditions shall
be improved upon development of the site. Developed release rates are lower than
historic at all discharge locations.
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Landings Office Park P.U.D. October 27, 1995
Final Drainage Report Page 7
REFERENCES
1. Storm Drainage Design Criteria and Construction
Standards, City of Fort Collins, Colorado, May, 1984.
2. Final Drainage Report for Heart Special Improvement
District, Engineering Professionals, Inc., December, 1984,
Revised: January, 1985.
3. ShooKo P.U.D. Addendum to the Final Drainage Report, TST, Inc.,
August 10, 1993.
4. Final Drainage Report for High Pointe P.U.D., Parsons & Associates,
Revised August 22, 1989.
5. Drainage Criteria Maunal, Urban Drainage and Flood
Control District, Wright -McLaughlin Engineers, Denver,
Colorado, March, 1969.
Landings Office Park P.U.D. October 27, 1995
Final Drainage Report Page 8
APPENDIX
PAGE
Historic Drainage.......................................................................... 1 - 4
Developed Drainage................................................................... 5 - 17
Developed Detention.................................................................. 18- 30
Design of Inlets, Sewers and Culverts ....................................... 31- 40
Off -site Swale Design.................................................................. 41- 45
Erosion Control Calculations.............:......................................... 46- 53
Heart Special Improvement District Final Drainage Report.......... 54- 58
ShopKo P.U.D. Letter Addenum................................................... 59- 62
Final Drainage Report for High Pointe P.U.D ............................... 63- 65
Off -Site Drainage Easement Description ..................................... 66- 67
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HISTORIC DRAINAGE
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HISTORIC DRAINAGE
BOARDWALK COMMERCIAL, Fort Collins, Colorado
File Number: HSTBSNH1.WOI
BASIN H2:
TOTAL AREA = A (ac) = 2.61
Area of Roofs (ac)=
0.1100
Area of Streets (ac)=
0.2300
Area of Gravel Parking (ac)=
0.200
Area of Lawn & Landscape(ac)=
1070
COMPOSITE RUNOFF COEFFICIENT:
RUNOFF COEFFICIENTS: (From Table 3-3
Calcs Bv: MBW
C for Roofs =
0.95
C for Asphalt =
0.95
C for Gravel =
0.50
C for Lawn =
0.25
C = 0.95(0.11+0.23ac)+ 0.50(.20ac)+ 0.25(2.07ac) = 0.36
2.61
Cf = 1.00 (Frequency Adjustment Factor; Storm Return Period of 2- Years)
Cf = 1.25 (Frequency Adjustment Factor: Storm Return Period of 100- Years)
OVERLAND FLOW: (From North to South Across Site)
Total Overland flow length = 257' T2 = 1.87 (1.1 , CCf) SQRT(L) = 16.4 min
L (ft)= 257 CUBRT(S)
S (%) = 97.3-97.56 = 3.79 17I00 = 1.87 (1.1 - CCf) SQRT(L) = 15.1 min
257 CUBRT(S)
C = 015
GUTTER FLOW: (East down Boardwalk to Curb Inlet)
L (ft)= 131 Tt =
S (%) = 87.56 - 85.78 = 1.36
131
V(fps) = 2.30 (From Figure 3-2)
2-YEAR TIME OF CONCENTRATION; Tc2 = 16.4 + 0.9 17.3 min
100-YEAR TIME OF CONCENTRATION: Tc100 = 15.1 + 0.9 16.1 min
RAINFALL INTENSITY:
FROM FIGURE 3-1: i2(in/hr)= 1.99 i100(in/hr)= 5.79
Q2(cfs) = CCf x i2 x A = 1.9
QI00(cfs) = CCf x i100 x A = 6.8
L = 0.9 min
60(V)
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HISTORIC DRAINAGE
BOARDWALK COMMERCIAL, Fort Collins, CO.
File Number: HSTBSNH2.WQ1 13-Feb-95 Calcs Bv: MBW
BASIN H2:
TOTAL AREA = A (ac)= 1.18
RUNOFF COEFFICIENTS: (From Table 3-3)
Area of Roofs (ac)=
0.0100
C for Roofs =
0.95
Area of Street (ac)=
0.1100
C for Streets =
0.95
Area of Lawn (ac)=
1.0600
C for Lawn =
0.25
Area of Gravel Parking (ac)=
0.000
C for Gravel =
0.50
COMPOSITE RUNOFF COEFFICIENT:
C = 0.95(0.01+ 0.11ac)+ 0.25(1.06ac) = 0.32
1.18
Cf = 1.00 (Frequency Adjustment Factor; Storm Return Period of 2- Years)
Cf = 1.25 (Frequency Adjustment Factor; Storm Return Period of 100- Years)
OVERLAND FLOW: (From South to North; Off -site)
Total Overland flow length = '163.00
T2 =
1.87 (1.1 - CCf) SQRT(L) = 11.0 min
L (ft)= 163
CUBRT(S)
S (%) = 95.3 - 85.0 =
6.32 , T100 =
1.87 (1.1 - CCf) SQRT(L) = 10.2 min
163
CUBRT(S)
C = 0.25
2-YEAR TIME OF CONCENTRATION, Tc2=
11.0 min
100-YEAR TIME OF CONCENTRATION, Tc100=
10.2 min
RAINFALL INTENSITY:
FROM FIGURE 3-1: i2(in/hr)= 2.40
i100(in/br)=
7.05
Q2(cfs) = CCf x i2 x A = 0.9
Q100(cfs) = CCf x i100 x A = 3.3
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northern enaineerina services, inc.
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HISTORIC DRAINAGE
BOARDWALK COMMERCIAL, Fort Collins, Colorado
File Number: HSTBSNH3.WQI 24-A r-95 Calcs By: MBW
BASIN H3:
TOTAL AREA = A (ac)= 0.3
RUNOFF COEFFICIENTS: (From Table 3-3)
Area of Roofs (ac)=
0.0000 C for Roofs = 0.95
Area of Streets (ac)=
01M C for Asphalt = 0.95
Area of Gravel Parking (ac)=-
0.000 C for Gravel = 0.50
Area of Lawn & Landscape(ac)=
0.096 C for Lawn = 0.25
COMPOSITE RUNOFF COEFFICIENT:
C =
0.95(0.204ac)+ 0.25(0.096ac) = 0.73
0.3
Cf = 1.00
(Frequency Adjustment Factor; Storm Return Period of 2- Years)
Cf = 1.25
(Frequency Adjustment Factor; Storm Return Period of 100- Years)
OVERLAND FLOW: (From Northeast to Southwest Across Site)
Total Overland flow length = 50' T2 = 1S7 (1.1 - CCf) SORT(L) = 4.8 min
L (ft)= 50 CUBRT(S)
S (%) = 98.0-91.65 = 12.70 T100 = 1.87 (1.1 - CCf) SQRT(L) = 45 min
50 CUBRT(S)
C = 0.25
GUTTER FLOW: (South down JFK to Curb Inlet)
L (ft)= 81 Tt = L = 0.5 min
S (%) = 91.65 -89.74 = 2.36 60(V)
81
V(fps) = 3.00 (From Figure 3-2)
2-YEAR TIME OF CONCENTRATION; Tc2 = 4.8 + OS = 53 min
100-YEAR TIME OF CONCENTRATION; Tc100 = 4.5 + 0.5 = 4.9 min
RAINFALL INTENSITY:
FROM FIGURE 3-1: i2(in/hr)= 3.29 i100(in/hr)= 9.00
Q2(cfs) = CCf x i2 x A = 0.7
0100(cfs) = CCf x i100 x A = 2.5
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DEVELOPED DRAINAGE
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DEVELOPED DRAINAGE
LANDINGS OFFICE PARK P.U.D., Fort Collins, CO.
File Number: DSNPNTDI.WQI 15-MaV-95 Calcs BV: MBW
DESIGN POINT D1: (Includes Basin D1)
TOTAL AREA = A (ac)=
0.8435
RUNOFF COEFFICIENTS:
(From Table 3-3)
Area of Roofs (ac)=
0.2738
C for Roofs =
0.95
Area of Concrete & Asphalt(ac)=
0.4708
C for Concrete =
0.95
Area of Gravel Parking (ac)=
0.0000
C for Gravel =
0.50
Area of Lavin (ac)=
0.0989
C for Lawn =
0.25
COMPOSITE RUNOFF COEFFICIENT:
C = 0.95(0.2738+.4708ac)+0.25(0.0989) = 0.87
0.8435
Cf = 1.00 (Frequency Adjustment Factor; Storm Return Period of 2- Years)
Cf = 1.25 (Frequency Adjustment Factor; Storm Return Period of 100- Years)
OVERLAND FLOW:
Total Overland flow length = 139'
L (ft)= 139
S (%) = 54.5 - 48.25 =
139
C = 0.95
GUTTER FLOW:
T2 = 1.87 (1.1 - CCf) SQRT(L) = 2.0 min
CUBRT(S)
4.50 T100 = 1.87 (1.1 - CCf) SORT(L) = 1.3 min
CUBRT(S)
L (f )= 194 Tt =
S (%) = 48.25 - 46.5 = 0.90
194
V(fps) = 1.90 (From Figure 3-2)
2-YEAR TIME OF CONCENTRATION; Tc2 = 2.0 + 1.7 = 3.7 min
100-YEAR TIME OF CONCENTRATION; TCI00 = 1.3 + 1.7 = 3.0 min
RAINFALL INTENSITY:
FROM FIGURE 3-1:
Q2(cfs) = CCf x Q x A =
Q1t10(cfs) = CCf x i100 x A =
L
60M
Use 5-min minimum
Use 5-min minimum
i2(in/hr)= 3.29 i100(in/hr)= 9.0
2.4
7.6
= 1.7 min
0
DEVELOPED DRAINAGE
LANDINGS OFFICE PARK P.U.D., Fort Collins, CO.
File Number: DSNPNTD2.WQI 15-May-95 Calcs BV: MBW
DESIGN POINT D2: (Includes Basin 132)
TOTAL AREA = A (ac)= 0.294
RUNOFF COEFFICIENTS: (From
Table 3-3)
Area of Roofs (ac)= 0.0000 C for Roofs =
0.95
Area of Concrete & Asphalt(ac)= 0.1560 C for Concrete =
0.95
Area of Gravel Parking (ac)= 0.0000 C for Gravel =
0.50
Area of Lawn (ac)= 0.1380 C for Lawn =
0.25
COMPOSITE RUNOFF COEFFICIENT:
C = 0.95(0.156ac)+0.25(0.138) =
0.62
0.294
Cf = 1.00 (Frequency Adjustment Factor; Storm Return Period of 2- Years)
Cf = 1.25 (Frequency Adjustment Factor; Storm Return Period of 100- Years)
OVERLAND FLOW:
Total Overland flow length = 50' T2 =
1.87 (1.1 - CCf) SQRT(L) = 5.6 min
L (ft)= 50
CUBRT(S)
S (%) = 47.0 - 42.87 = 8.26 T100 =
1.87 (1.1 - CCf) SORT(L) = 5.2 min
50
CUBRT(S)
C = 0.25
GUTTER FLOW: (North Down Landings Drive to Propertyline)
L (ft)= 132 Tt =
L = 1.0 min
S (%) = 42.87 - 41.0 = 1.42
60(V)
132
V(fps) = 2.30 (From Figure 3-2)
2-YEAR TIME OF CONCENTRATION; Tc2 = 6.5 min
100-YEAR TIME OF CONCENTRATION; Tc100 = 6.1 min
RAINFALL INTENSITY: '
FROM FIGURE 3-1:
02(cfs) = CCf x i2 x A =
Q 100(cfs) = CCf x i I00 x A=
i2(in/hr)= 2.95 000(in/hr)= 8.5
0.5
1.9
0
DEVELOPED DRAINAGE
LANDINGS OFFICE PARK P.U.D., Fort Collins, CO.
File Number: DSNPNTD3.WQ1 1
DESIGN POINT D3: (Includes Basin D3)
TOTAL AREA = A (ac)= 0.336
RUNOFF COEFFICIENTS:
(From Table
Area of Roofs (ac)=
0.0000
C for Roofs =
0.95
Area of Concrete & Asphalt(ac)=
0.2130
C for Concrete =
0.95
Area of Gravel Parking (ac)=
0.0000
C for Gravel =
0.50
Area of Lawn (ac)=
0.1230
C for Lawn =
0.25
COMPOSITE RUNOFF COEFFICIENT:
C = 0.95(0.213ac)+0.25(0.123) = 0.69
0.336
Cf = 1.00 (Frequency Adjustment Factor; Storm Return Period of 2- Years)
Cf = 1.25 (Frequency Adjustment Factor; Storm Return Period of 100- Years)
OVERLAND FLOW:
Total Overland flow length = 65'
L (ft)= 65
S (%) = 53.0 - 48.11 =
65
C = 0.25
GUTTER FLOW: (To Existing 15' Curb Inlet)
Caics Bv: MBW
T2 = 1.87 (1.1 - CCf) SQRT(L) = 6.5 min
CUBRT(S)
7.52 T100 = 1.87 (1.1 - CCf) SORT(L) = 6.1 min
CUBRT(S)
L (ft)= 106 Tt =
S (%) = 48.11 - 45.78 = 2.20
106
V(fps) = 2.90 (From Figure 3-2)
2-YEAR TIME OF CONCENTRATION; Tc2 = 6.5 + 0.6 = 7.2 min
100-YEAR TIME OF CONCENTRATION; Tc100 = 6.1 + 0.6 = 6.7 min
RAINFALL INTENSITY:
FROM FIGURE 3-1: i2(in/hr)= 2.86 i100(in/hr)= 8.0
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Q2(cfs) = CCf x i2 x A = 0.7
Q100(cfs) = CCf x i100 x A = 2.3
L = 0.6 min
60(V)
0
DEVELOPED DRAINAGE
LANDINGS OFFICE PARK P.U.D., Fort Collins, CO.
File Number: DSNPNTD4.WQI 15-Mav-95 Calcs Bv: MBW
DESIGN POINT D4: (Includes Basin 134)
TOTAL AREA = A (ac)= 0.38
RUNOFF COEFFICIENTS:
(From Table 3-3)
Area of Roofs (ac)=
0.1080 C for Roofs =
0.95
Area of Concrete & Asphalt(ac)=
0.2170 C for Concrete =
0.95
Area of Gravel Parking (ac)=
0.0000 C for Gravel =
0.50
Area of Lawn (ac)=
0.0550 C for Lawn =
0.25
COMPOSITE RUNOFF COEFFICIENT:
C = 0.95(0.108+0.217ac)+0.25(0.055) =
0.85
0.38
Cf = 1.00
(Frequency Adjustment Factor; Storm Return
Period of 2- Years)
Cf = 1.25
(Frequency Adjustment Factor; Storm Return
Period of 100- Years)
OVERLAND FLOW: (Across Paved Parking)
Total Overland flow length = 119'
L (ft)= 119
S (%) = 49.0 - 44.0 =
119
C = 0.95
72 = 1.87 (1.1 - CCf) SQRT(L) = 1.9 min
CUBRT(S)
4.20 T100 = 1.87 (1.1 - CCf) SORT(L) = 1.3 min
CUBRT(S)
GUTTER FLOW: (To Parking Lot Detention Outlet)
L (ft)= 67 Tt = L
S (%) = 44.0 - 42.0 = 2.99 60(V)
67
V(fps) = 1.35 (From Figure 3-2)
2-YEAR TIME OF CONCENTRATION; Tc2 = 1.9 + 0.8 = 2.7 min (Use 5-minute minimum)
100-YEAR TIME OF CONCENTRATION; TC100 = 1.3 + 0.8 = 2.1 min (Use 5-minute minimum)
RAINFALL INTENSITY:
FROM FIGURE 3-1: i2(in/hr)= 3.29 i100(in/hr)= 9.0
I
02(cfs) = CCf x i2 x A = 1.1
QI00(cfs) = CCf x i100 x A = 3.4
= 0.8 min
1
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DEVELOPED DRAINAGE
LANDINGS OFFICE PARK P.U.D., Fort Collins, CO.
File Number: DSNPNTD5.WQ1 15-Mav-95 Calcs Bv: MBW
DESIGN POINT D5: (Includes Basin D5)
TOTAL AREA = A (ac)= 0.45
RUNOFF COEFFICIENTS: (From Table 3-3)
Area of Roofs (ac)= 0.1720 C for Roofs = 0.95
Area of Concrete & Asphalt(ac)= 0.1610 C for Concrete = 0.95
Area of Gravel Parking (ac)= 0.0000 C for Gravel = 0.50
Area of Lawn (ac)= 0.1170 C for Lawn = 0.25
COMPOSITE RUNOFF COEFFICIENT:
C = 0.95(0.172+0.161ac)+0.25(0.117) = 0.77
0.45
Cf = 1.00 (Frequency Adjustment Factor; Storm Return Period of 2 & 10 - Years)
Cf = 1.25 (Frequency Adjustment Factor; Storm Return Period of 100- Years)
OVERLAND FLOW: (Across Parking Lot)
Total Overland flow length = 131' 1'2& T10 1.87 (1.1 - CCf) SQRT(L) = 2.0 min
L (ft)= 131 CUBRT(S)
S (%) = 54.0 - 48.84 = 3.94 T100 = 1.87 (1.1 - CCf) SQRT(L) = 1.4 min
131 CUBRT(S)
C = 0.95
GUTTER FLOW:
L (ft)=
19
S (%) =
48.84 - 48.54 =
19
V(fps) =
2.50
SWALE FLOW: (From
L (ft)=
107
S (%) =
48.54 - 42.0 =
107
V(fps) =
3.70
2 & 10 -YEAR TIME OF CONCENTRATION; _
100-YEAR TIME OF CONCENTRATION; T000 =
RAINFALL INTENSITY:
FROM FIGURE 3-1:
i2(in/hr)=
Q10(cfs) = CCf x i2 x A =
2.0
Q2(cfs) = CCf x i2 x A =
1.1
Q100(cfs) = CCf x i100 x A =
3.9
Tt = L = 0.1
1.58 60(V)
(From Figure 3-2)
Tt = L = 0.5 min
6.11 60(V)
(From Figure 3-2)
2.6 min (Use 5-minute minimum)
2.0 min (Use 5-minute minimum)
3.29 i100(in/hr)= 9.0 i10(in/hr)= 5.7
O
71
DEVELOPED DRAINAGE
LANDINGS OFFICE PARK P.U.D., Fort Collins, CO.
File Number: DSNPNTD6.WQ1 15-May-95 Calcs Bv: MBW
't DESIGN POINT D6: (Includes Basin D6
11 TOTAL AREA = A (ac)= 0.500
RUNOFF COEFFICIENTS:
(From Table 3-3)
Area of Roofs (ac)=
0.0000
C for Roofs =
0.95
'
Area of Concrete & Asphalt(ac)=
0.3290
C for Concrete =
0.95
Area of Gravel Parking (ac)=
0.0000
C for Gravel =
0.50
Area of Lawn (ac)=
0.1710
C for Lawn =
0.25
COMPOSITE RUNOFF COEFFICIENT:
C = 0.95(0.329ac)+0.25(0.171)
= 0.71
0.5
Cf = 1.00 (Frequency Adjustment Factor; Storm Return Period of 2- Years)
Cf = 1.25 (Frequency Adjustment Factor; Storm Return Period of 100- Years)
OVERLAND FLOW:
Total Overland flow length = 43'
T2 = 1.87 (1.1 - CCf) SQRT(L) = 5.1 min
L (ft)= 43
CUBRT(S)
S (%) = 49.0 - 45.33
= 8.53 T100 = 1.87 (1.1 - CCf) SORT(L) = 4.7 min
43
CUBRT(S)
C = 0.25
GUTTER FLOW: (To Existing 4' Curb Inlet)
L (ft)= 462
Tt = L = 4.3 min
S 45.33 - 41.82 =
0.76 60(V)
462
V(fps) = 1.80
(From Figure 3-2)
2-YEAR TIME OF CONCENTRATION; Tc2 =
9.4 min
100-YEAR TIME OF CONCENTRATION; Tc100 =
9.0 min
RAINFALL INTENSITY:
FROM FIGURE 3-1: i2(in/hr)=
2.57 i100(in/hr)= 7.5
Q2(cfs) = CCf x i2 x A = 0.9
Q100(cfs) = CCf x i100 x A = 3.3
a
DEVELOPED DRAINAGE
LANDINGS OFFICE PARK P.U.D., Fort Collins, CO.
File Number: DSNPNTD7.WQ1 03-Apr-95 CaIcs Bv: MBW
DESIGN POINT D7: (Includes Basin D7)
TOTAL AREA = A (ac)= 0.185
RUNOFF COEFFICIENTS: (From Table 3-3)
Area of Roofs (ac)= 0.0000
C for Roofs =
0.95
Area of Concrete & Asphalt(ac) 0.1310
C for Concrete =
0.95
Area of Gravel Parldng (ac)= 0.0000
C for Gravel =
0.50
Area of Lawn (ac)= 0.0540
C for Lawn =
0.25
COMPOSITE RUNOFF COEFFICIENT:
C = 0.95(0.131ac)+0.25(0.054) = 0.75
0.185
Cf = 1.00 (Frequency Adjustment Factor; Storm Return Period of 2- Years)
Cf = 1.25 (Frequency Adjustment Factor; Storm Return Period of 100- Years)
OVERLAND FLOW:
Total Overland flow length = 13.5' T2 = 1.87 (1.1 - CCf) SQRT(L) = 4.6 min
L (ft)= 13.5 CUBRT(S)
S (%) = 54.57 - 54.3 = 2.00 T100 = 1.87 (1.1 - CCf) SQRT(L) = 4.3 min
13.5 CUBRT(S)
C = 0.25
OVERLAND FLOW:
Total Overland flow length = 104' T2 = 1.87 (1.1 - CCf) SQRT(L) = 1.7 min
L (ft)= 104 CUBRT(S)
S (%) = 54.3 - 49.3 = 4.81 T100 = 1.87 (1.1 - CCf) SQRT(L) = 1.1 min
104 CUBRT(S)
C = 0.95
RAINFALL INTENSITY:
FROM FIGURE 3-1: i2(in/hr)= 3.00 i100(in/hr)= 9.00
Q2(cfs) = CCf x i2 x A 0.4
QI00(cfs) = CCf x i100 x A 1.6
DEVELOPED DRAINAGE
LANDINGS OFFICE PARK P.U.D., Fort Collins, CO.
File Number: DSNPNTD8.WQ1
DESIGN POINT D8: (Includes Basin D8)
TOTAL AREA = A (ac)= 0.0518
Area of Roofs (ac)= 0.0000
Area of Concrete & Asphalt(ac)= 0.0518
Area of Gravel Parking (ac)= 0.0000
Area of Lawn (ac)= 0.0000
COMPOSITE RUNOFF COEFFICIENT:
RUNOFF COEFFICIENTS: (From Table 3-3
15-Mav-95 Calcs Bv: MBW
C for Roofs =
0.95
C for Concrete =
0.95
C for Gravel =
0.50
C for Lawn =
0.25
C = 0.95(0.0518ac) = 0.95
0.0518
Cf = 1.00 (Frequency Adjustment Factor; Storm Return Period of 2- Years)
Cf = 1.25 (Frequency Adjustment Factor; Storm Return Period of 100- Years)
OVERLAND FLOW:
Total Overland flow length = 80'
L (ft)= 80
S (%) = 47.75 - 44.0 =
80
C = 0.95
2-YEAR TIME OF CONCENTRATION; Tc2 =
100-YEAR TIME OF CONCENTRATION; Tc100 =
RAINFALL INTENSITY:
FROM FIGURE 3-1: i2(in/hr)= 3.3
Q2(cfs) = CCf x i2 x A = 0.2
QI00(cfs) = CCf x i100 x A = 0.5
T2 = 1.87 (1.1 - CCf) SQRT(L) = 1.5 min
CUBRT(S)
4.69 T100 = 1.87 (1.1 - CCf) SQRT(L) = 1.0 min
CUBRT(S)
1.5 min Use 5 min Tc
1.0 min Use 5 min Tc
i100(in/hr)= 9.0
DEVELOPED DRAINAGE
LANDINGS OFFICE PARK P.U.D., Fort Collins, CO.
File Number: DEVBSND9.WQ1 15-May-95 CaIcs Bv: MBW
DESIGN POINT D9: (Includes Basins' D1, D5, D7, D8 and D9)
TOTAL AREA = A (ac)=
2.568
RUNOFF COEFFICIENTS: (From Table 3-3)
Area of Roofs (ac)=
0.7430
C for Roofs =
0.95
Area of Concrete & Asphalt(ac)=
1.2000
C for Concrete =
0.95
Area of Gravel Parking (ac)=
0.0000
C for Gravel =
0.50
Area of Lawn (ac)=
0.6300
C for Lawn =
0.25
COMPOSITE RUNOFF COEFFICIENT
C = 0.95(0.743+1.20ac)+0.25(0.630) = 0.78
2.568
Cf = 1.00 (Frequency Adjustment Factor; Storm Return Period of 2- Years)
Cf = 1.25 (Frequency Adjustment Factor; Storm Return Period of 100- Years)
AT DESIGN POINT D5: Tc2= 2.6 min TC100= 2.0 min
CULVERT FLOW:
L (ft)= 164.24
S(%G)= 42.5-41.5=
164.24
Tt =
0.61
V(fps) = 2.26 (From HY8 Output)
SWALE FLOW:
L (ft)= 89
S(%)= 41.5-39.78=
89
1.93
Tt =
L = 1.2
60M
L = 0.7 min
60(V)
V(fps) = 2.00 (From Figure 3-2)
2-YEAR TIME OF CONCENTRATION; Tc2 = 4.6 min (Use 5-minute minimum)
100-YEAR TIME OF CONCENTRATION; TOM = 4.0 min (Use 5-minute minimum)
RAINFALL INTENSITY:
FROM FIGURE 3-1: i2(in/hr)= 3.29
Q2(cfs) = CCf x i2 x A = 6.6
QI00(cfs) = CCf x i100 x A = 22.5
i100(in/hr)= 9.0
14
DEVELOPED DRAINAGE
LANDINGS OFFICE PARK P.U.D., Fort Collins, CO.
File Number: DSNPTDIO.WQI 03-Apr-95 Calcs By: MBW
DESIGN POINT D10: (Includes Basins' D2, D4 & Off -Site Basin)
TOTAL AREA = A (ac)= 0.434
RUNOFF COEFFICIENTS: (From Table 3-3)
Area of Roofs (ac)= 0.0000
C for Roofs =
0.95
Area of Concrete & Asphalt(ac) 0.2760
C for Concrete =
0.95
Area of Gravel Parldng (ac)= 0.0000
C for Gravel =
0.50
Area of Lawn (ac)= 0.1580
C for Lawn =
0.25
COMPOSITE RUNOFF COEFFICIENT:
C = 0.95(0.276ac)+0.25(0.158) = 0.70
0.434
Cf = 1.00 (Frequency Adjustment Factor; Storm Return Period of 2- Years)
Cf = 1.25 (Frequency Adjustment Factor; Storm Return Period of 100- Years)
OVERLAND FLOW: (From Design Point 132)
Total Overland flow length = 50' T2 = 1.87 (1.1 - CCf) SQRT(L) = 5.6 min
L (ft)= 50 CUBRT(S)
S (%) = 47.0 - 42.87 = 8.26 T100 = 1.87 (1.1 - CCf) SQRT(L) = 5.2 min
50 CUBRT(S)
C = 0.25
GUTTER FLOW: (North Down Landings Drive to Existing Curb Inlet)
L (ft)= 299 Tt =
S (%) = 42.87 - 37.3 = 1.86
299
V(fps) = 2.80 (From Figure 3-2)
2-YEAR TIME OF CONCENTRATION; Tc2 = 4.6 7.3 min
100-YEAR TIME OF CONCENTRATION; Tc100 = 2.4 6.9 min
RAINFALL INTENSITY:
FROM FIGURE 3-1: i2(in/hr)= 2.82 i100(in/hr) 7.5
Q2(cfs) = CCf x i2 x A 0.9 /
Q100(cfs) = CCf x i100 x A 2.8 g-:5
L = 1.8 min
60(V)
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Detention Pond D1
Inout Parameters:
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Area of Orifice (A) = 0.0491 fe
Orifice Invert Elevation
Orifice Centerline Elevation
Coefficient of Discharge (Cd)
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----------------------------------------------- C
UDINLET INLET HYDARULICS AND SIZING
DEVELOPED BY
DR. JAMES GUO, CIVIL ENG DEPT. U OF COLORADO AT DENVER
�i SUPPORTED BY METRO DENVER CITIES/COUNTIES AND UD&FCD
---------------------------------I--------------------------------------------
SER:Northern Engineering Services -Ft Collins Colorado .......................
DATE 05-15-1995 AT TIME 11:46:10
*** PROJECT TITLE: LANDING P.U.D.
*** CURB OPENING INLET HYDRAULICS AND SIZING:
'
INLET ID NUMBER: 1
INLET HYDRAULICS: IN A SUMP.
GIVEN INLET
DESIGN INFORMATION:
GIVEN CURB OPENING LENGTH (ft)=
4.00
HEIGHT OF CURB OPENING (in)=
6.00
INCLINED THROAT ANGLE (degree)=
63.43
LATERAL WIDTH OF DEPRESSION (ft)=
SUMP DEPTH (ft)=
2_0
0.19
Note: The sump depth is additional
depth to flow depth.
STREET GEOMETRIES:
STREET LONGITUDINAL SLOPE (%) =
2.00
STREET CROSS SLOPE (%)
STREET MANNING N
2.00
0.016
GUTTER DEPRESSlON (inch)=
2.00
GUTTER WIDTH (ft) =
2.00
ISTREET
FLOW HYDRAULICS:
WATER SPREAD ON STREET (ft) =
11.97
GUTTER FLOW DEPTH (ft) =
0.41
FLOW VELOCITY ON STREET (fps)=
4.38
FLOW CROSS SECTION AREA (sq ft)=
1.60
GRATE CLOGGING FACTOR (%)=
50.00
CURB OPENNING CLOGGING FACTOR(%)=
20.00
INLET INTERCEPTION CAPACITY:
IDEAL INTERCEPTION CAPACITY (cfs)= 8.12
BY FAA HEC-12 METHOD: DESIGN FLOW (cfs)=
FLOW INTERCEPTED (cfs)=
CARRY-OVER FLOW (cfs)=
BY DENVER UDFCD METHOD: DESIGN FLOW (cfs)=
FLOW INTERCEPTED (cfs)=
CARRY-OVER FLOW (cfs)=
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Elevation v.s. Discharge Table
for
Detention Pond D4
Inout Parameters:
Orifice Diameter = 3.0" (0.25')
Area of Orifice (A) = 0.0491 fe
Orifice Invert Elevation = 5041.68
Orifice Centerline Elevation = 5041.81
Coefficient of Discharge (Cd) = Varies with head
(Table 4-3, Brater & King)
Orifice Equation: O = CdAV2gh
Northern Engineering Services, Inc.
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for
Detention Pond D4
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11
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--------------------------------------------------------------------------- �I
UDINLET: INLET HYDARULICS AND SIZING
DEVELOPED BY
DR. JAMES GUO, CIVIL ENG DEPT. U OF COLORADO AT DENVER
SUPPORTED BY METRO DENVER CITIES/COUNTIES AND UD&FCD
-----------------------------------------------------------------------------
ER:Northern Engineering Services -Ft Collins Colorado .......................
DATE 04-26-1995 AT TIME 08:20:27
*** PROJECT TITLE: LANDINGS P.U.D.
*** CURB OPENING INLET HYDRAULICS AND SIZING:
INLET ID NUMBER: 1 �CHr�rS Ii�1Lr r71 )
INLET HYDRAULICS: IN A SUMP.
GIVEN INLET DESIGN INFORMATION:
GIVEN CURB OPENING LENGTH (ft)=
4.00
HEIGHT OF CURB OPENING
(in)=
6.00
INCLINED THROAT ANGLE
(degree)=
63.43
'
LATERAL WIDTH OF DEPRESSION (ft)=
SUMP DEPTH (ft)=
2.00
0.14
_
Note: The sump depth
is additional
depth to flow depth.
STREET GEOMETRIES:
STREET LONGITUDINAL SLOPE (%) =
0.90
STREET CROSS SLOPE
M
3.00
STREET MANNING N
0.016
GUTTER DEPRESSION
(inch)=
2.00
_
GUTTER WIDTH
(ft) =
2.00
STREET FLOW HYDRAULICS:
WATER SPREAD ON STREET
(ft) =
6.59
GUTTER FLOW DEPTH
(ft) =
0.36
FLOW VELOCITY ON STREET
(fps)=
2.92
'
FLOW CROSS SECTION AREA
GRATE CLOGGING FACTOR
(sq ft)=
(%)_•
0.82
50.00
CURB OPENNING CLOGGING
FACTOR(%)=
20.00
INLET INTERCEPTION CAPACITY:
IDEAL INTERCEPTION CAPACITY (cfs)= 6.26
BY FAA HEC-12 METHOD: DESIGN FLOW (cfs)=
FLOW INTERCEPTED (cfs)=
CARRY-OVER FLOW (cfs)=
BY DENVER UDFCD METHOD: DESIGN FLOW (cfs)=
FLOW INTERCEPTED (cfs)=
CARRY-OVER FLOW (cfs)=
2. 40 - C72_ E i_-).P. D 1
2.40
0.00
2.40
2.40
0.00
I
---------------------------------------------------------------------
UDINLET: INLET HYDARULICS AND SIZING
DEVELOPED BY
DR. JAMES GUO, CIVIL ENG DEPT. U OF COLORADO AT DENVER
SUPPORTED BY METRO DENVER CITIES/COUNTIES AND UD&FCD
------------------------------------------------------------------------------
ER:Northern Engineering Services -Ft Collins Colorado..: ....................
DATE 05-15-1995 AT TIME 11:23:56
*** PROJECT TITLE: LANDINGS P.U.D.
*** CURB OPENING INLET HYDRAULICS AND SIZING:
INLET ID
NUMBER: 1
( INt_GT LD I )
INLET
HYDRAULICS:
IN A SUMP.
GIVEN INLET DESIGN INFORMATION:
GIVEN CURB OPENING LENGTH (ft)= 4.00
HEIGHT OF CURB OPENING (in)= 6.00
INCLINED THROAT ANGLE (degree)= 63.43
' LATERAL WIDTH OF DEPRESSION (ft)= 2.00
SUMP DEPTH (ft)= 0.50 G^'s�=�- �� 4�•33
Note: The sump depth is additional depth to flow depth.
STREET GEOMETRIES:
STREET LONGITUDINAL SLOPE (%) =
0.90
STREET CROSS SLOPE
(%) _
3.00
STREET MANNING N
0.016
GUTTER DEPRESSION
(inch)=
2.00
GUTTER WIDTH
(ft) =
2.00
STREET FLOW HYDRAULICS:
WATER SPREAD ON STREET
(ft) =
11.41
'
GUTTER FLOW DEPTH
(ft) =
0.51
FLOW VELOCITY ON STREET
(fps)=
3.59
FLOW CROSS SECTION AREA
GRATE CLOGGING FACTOR
(sq ft)=
(%)=
2.12
50.00
CURB OPENNING CLOGGING
FACTOR(%)=
20.00
'
INLET INTERCEPTION CAPACITY:
IDEAL INTERCEPTION CAPACITY
(cfs)=
9.53
BY FAA HEC-12 METHOD:
DESIGN FLOW
(cfs)=
7.60
FLOW INTERCEPTED
(cfs)=
7.60
'
CARRY-OVER
FLOW (cfs)=
0.00
BY DENVER UDFCD METHOD:
DESIGN FLOW
(cfs)=
7.60
FLOW INTERCEPTED
CARRY-OVER
(cfs)=
FLOW (cfs)=
7.60
0.00
I
Culvert Rating Curve: Storm Sewer Line D5
CURRENT DATE: 05-15-1995
CURRENT TIME: 11:28:53
FRWA CULVERT ANALYSIS
HY-8, VERSION 4.1
FILE DATE: 02-15-1995
FILE NAME: BWC
C
U
SITE DATA
CULVERT
SHAPE,
MATERIAL,
INLET
L
INLET
OUTLET
CULVERT
BARRELS
V
ELEV.
ELEV.
LENGTH
SHAPE
SPAN
RISE
MANNING
INLET
(FT)
(FT)
(FT)
MATERIAL
(FT)
(FT)
n
TYPE
1
5042.50
5041.50
164.24
1 ADS N-12
1.50
1.50
.010
IMPR SDT CIR
1
3
4
5
6
SUMMARY OF
CULVERT
FLOWS (CFS)
FILE:
BWC
DATE: 02-15-1995
ELEV (FT)
TOTAL
1
2
3
4
5
6 ROADWAY ITR
5042.50
0
0
0
0
0
0
0 O 1
5042.99
1
1
0
0
0
0
0 0 1
5043.21
2
2
0
0
0
0
0 0 1
5043.31
3
3
0
0
0
0
0 0 1
5043.48
4
4
0
0
0
0
0 0 1
5043.63
5
5
0
0
0
0
0 0 1
5043.78
6
6
0
0
0
0
0 0 1
5043.94
1
1
0
0
0
0
0 0 1
5044.08
8
8
0
0
0
0
0 0 1
5044.23
9
9
0
0
0
0
0 0 1
5044.38
10
10
0
0
0
0
0 0 1
5044.68
11
11
0
0
0
0
0 OVERTOPPING
I
O
1
2
1 CURRENT DATE: 05-15-1995 FILE DATE: 02-15-1995
CURRENT TIME: 11:28:53 FILE NAME: BWC
1 PERFORMANCE CURVE FOR CULVERT i 1 - I ( 1.5 BY 1.5 ) RCP
DIS- HEAD- INLET OUTLET
1 CHARGE WATER CONTROL CONTROL FLOW NORMAL CRITICAL OUTLET TAILWATER
FLOW ELEV. DEPTH DEPTH TYPE DEPTH DEPTH VEL. DEPTH VEL. DEPTH
(cfs) (ft) (ft) (ft) <F4> (ft) (ft) (fps) (ft) (fps) (ft)
1
1
1
1
n
0
1
1
0 5042.50 0.00 0.00 0-NF 0.00 0.00 0.00 0.00 0.00 0.88
1 5042.99 0.49 0.49 I-S2n 0.31 0.37 3.80 0.31 0.00 0.88
2 5043.21 0.71 0.71 1-S2u 0.44 0.53 4.58 0.44 0.00 0.88
3 5043.31 0.81 0.81 1-S2u 0.51 0.61 4.96 0.51 0.00 0.88
4 5043.48 0.98 0.98 1-S2u 0.64 0.76 5.57 0.64 0.00 0.88
5 5043.63 1.13 1.13 1-Stu 0.73 0.86 5.87 0.73 0.00 0.88
6 5043.78 1.28 1.28 i-S1n 0.81 0.94 6.14 0.81 0.00 0.88
7 5043.94 1.44 1.44 1-S2n 0.90 1.02 6.36 0.90 0.00 0.88
8 5044.08 1.58 1.58 5-S2u 0.98 1.09 6.54 0.98 0.00 0.88
9 5044.23 1.73 1.73 5-S2u 1.07 1.16 6.66 1.07 0.00 0.88
10 5044.38 1.88 1.88 5-S2u 1.17 1.22 6.75 1.17 0.00 0.88
El. inlet face invert 5042.50 ft E1. outlet invert $041.50 ft
E1. inlet throat invert 5042.47 ft El. inlet crest 0.00 ft
*$$** SITE DATA xx>== CULVERT INVERT s:tsst:sss M
INLET STATION (FT)
0.00
INLET ELEVATION (FT)
5042.50
OUTLET STATION (FT)
169.90
OUTLET ELEVATION (FT)
5041.50
NUMBER OF BARRELS
1
SLOPE (V-FT/H-FT)
0.0059
CULVERT LENGTH ALONG SLOPE (FT)
164.24
f==== CULVERT DATA SUMMARY ==3==ssssssssssssust:::
BARREL SHAPE CIRCULAR
BARREL DIAMETER 1.50 FT
BARREL MATERIAL ADS H-12 POLYETHYLENE
BARREL MANNING'S N 0.010
INLET TYPE IMPR SOT CIRC
INLET EDGE AND WALL SQUARE EDGE TOP (26-90 DEG WINGWALL)
INLET DEPRESSION MORE
SIDE -TAPERED CIRCULAR IMPROVED INLET tsttttt
FACE WIDTH 4.33 FT
SIDE TAPER (4:1 TO 6:1) (E:1) 4.00
FACE HEIGHT 1.50 FT
1
3
CURRENT DATE: 05-15-1995 FILE DATE: 02-15-1995
CURRENT TIME: 11:28:53 FILE NAME: BNC
TAILWATER
CONSTANT WATER SURFACE ELEVATION (Pond DI 100-Yr WSEL)
5042.38
ROADWAY OVERTOPPING DATA
ROADWAY SURFACE PAVED
EMBANKMENT TOP WIDTH (FT) 30.00
t==== USER DEFINED ROADWAY PROFILE
CROSS-SECTION K Y
COORD. NO. (FT) (FT)
1 0.00 5044.68
2 16.76 5045.92
3 32.00 5045.52
11
0
STORM SEWER SYSTEM DESIGN USING UDSEWER YODEL
Developed by Dr. James Goo, Civil Eng. Dept, U. of Colorado
at Denver
Metro Denver Cities/Counties A UDFCD Pool Fund
Study
DSER:NORTHERN ENG SERVICES INC-FT COLLINS COLORADO ...........................
ON DATA 04-26-1995 AT TIME 12:05:36 VERSION=03-26-1994
PROJECT TITLE :Landings P.D.D.; Storm Sewer Line D7
'
jt= RETURN PERIOD OF FLOOD IS 100 YEARS
'
RAINFALL INTENSITY FORMULA IS GIVEN
Ot SUMMARY OF SUBBASIN RUNOFF PREDICTIONS
'
------------ ---- - - ------- TIME OF CONCENTRATION --------------
--------
MANHOLE BASIN OVERLAND GUTTER BASIN RAIN I
PEAK FLOW
'
ID NUMBER AREA = C To (MIN) Tf (MIN) Tc (MIN) IRCH/HR
----------------------------------------------------------------------
CFS
1.00 0.00 0.00 0.00 0.00 0.00
0.00
2.00 0.00 0.00 0.00 0.00 4.58
3.00 0.14 0.00 0.00 5.00 11.53
0.00
1.60
'
THE SHORTEST DESIGN RAINFALL DURATION IS FIVE MINUTES
DENVER CRITERIA WAS NOT USED TO CHECK THE COMPUTATED Tc.
i== SUMMARY OF HYDRAULICS AT MANHOLES
-------------------------------------------------------------------------------
MANHOLE CNTRBTING RAINFALL RAINFALL DESIGN GROUND
WATER COMMENTS
ID NUMBER AREA i C DURATION INTENSITY PEAK FLOW ELEVATION
MINUTES INCH/HR CFS FEET
ELEVATION
FEET
- --- -------------- ---------------------------------------
1.00 0.00 0.00 0.00 0.00 5047.50
5047.13 OK
2.00 0.14 5.00 11.53 1.60 5048.45
5047.22 OK
3.00 0.14 5.00 11.53 1.60 5049.50
5048.03 OK
OK MEANS WATER ELEVATION IS LOWER THAN GROUND ELEVATION
SUMMARY OF SEWER HYDRAULICS
NOTE: THE GIVEN FLOW DEPTH -TO -SEWER SIZE RATIO= .8
SEWER MANHOLE NUMBER SEWER REQUIRED SUGGESTED
EXISTING
ID NUMBER UPSTREAM DNSTREAM SHAPE DIA(RISE) DIA(RISE)
DIA(RISE) WIDTH
ID NO. ID NO. (1N) (FT) (1N) (FT)
(IN) (FT) (FT)
---------- - -----------------------------------------------------------
1.00 1.00 1.00 ROUND 10.45 15.00
12.00 0.00
2.00 3.00 2.00 ROUND 8.57 15.00
DIVERSION UNITS FOR ROUND AND ARCH SEWER ARE IN INCHES
12.00 0.00
DIMENSION UNITS FOR BOX SEWER ARE IN FEET
'
r
' REQUIRED DIAMETER WAS DETERMINED BY SEWER HYDRAULIC CAPACITY.
S➢GGESTED DIAMETER WAS DETERMINED BY COMMERCIALLY AVAILABLE SIZE.
FOR A NEW SEWER, FLOW WAS ANALYZED BY THE SUGGESTED SEWER SIZE; OTHERWISE,
EKISITNG SIZE WAS USED
SEWER DESIGN FLOW NORMAL
NORAAL
CRITIC CRITIC FULL FROUDE COMMENT
ID FLOW Q FULL Q DEPTH
VLCITY
DEPTH VLCITY VLCITY NO.
NUMBER CFS CFS FEET
FPS
FEET FPS FPS
----------------------------------------------------------------------
1.0 1.6 2.3 0.61
3.19
0.54 3.70 2.04 0.78 V-OK
2.0 1.6 3.9 0.44
4.76
0.54 3.70 2.04 1.44 V-OK
'
FROUDE NUMBER=0 INDICATES THAT A
PRESS➢RED
FLOW OCCDRS
----------------------------------------------------------------------
SEWER SLOPE INVERT ELEVATION
BURIED DEPTH COMMENTS
'
ID NUMBER UPSTREAM DNSTREAM
UPSTREAM DNSTREAM
3 (FT)
(FT)
(FT) (FT)
'
-----------------------------------------------------------
1.00 0.25 5046.44
5046.13
1.01 0.37 OE
2.00 0.72 5047.49
5046.44
1.01 1.01 OK
OE MEANS BURIED DEPTH IS GREATER
THAN REQUIRED
SOIL COVER OF 1 FEET
M 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
1.00 125.38 0.00
5047.44
5047.13 5047.22 5047.13 SUBCR
'
2.00 146.21 0.00
5048.49
5047.44 5048.03 5047.22 JUMP
PRSS'ED=PRESSDRED FLOW; JUMP=POSSIBLE HYDRAULIC JUMP; SUBCR=SUBCRITICAL FLOW
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 2.00 5047.31 0.18
0.05
----- ---------------------------
0.00 0.00 0.00 1.00 5047.13
2.0 3.00 5048.24 0.84
1.32
0.09 0.00 0.00 2.00 5047.31
BEND LOSS =BEND K+ FLOWING FULL VHEA.D IN SEWER.
LATERAL LOSS= OUTFLOW FULL VHEAD-JCT LOSS K=INFLOW FULL VHEAD
FRICTION LOSS4 MEANS IT IS NEGLIGIBLE OR POSSIBLE ERROR DUE TO JUMP.
' FRICTION LOSS INCLUDES SEWER INVERT DROP AT MANHOLE
NOTICE: VREAD DENOTES THE VELOCITY HEAD OF FULL FLOW CONDITION.
A MINIMUM JUCTION LOSS OF 0.05 FT WORLD BE INTRODUCED UNLESS LATERAL K=O.
' FRICTION LOSS WAS ESTIMATED BY BACKWATER CURVE COMPUTATIONS,
------------------------------------------------------------------------------
------------------------------------------------------------------------------
STORY SEWER SYSTEM DESIGN USING UDSEWER YODEL
Developed by Dr. Jaies Gun, Civil Eng. Dept, U. of Colorado at Denver
Metro Denver Cities/Counties A UDFCD Pool Fund Study
------------------------------------------------------------------------------
------------------------------------------------------------------------------
USER:NORTHERN EKG SERVICES INC-FT COLLINS COLORADO ...........................
ON DATA 05-17-1995 AT TIME 06:59:38 VERSION43-26-1994
PROJECT TITLE :Landings P.U.D.: Storm Sewer Line D8
ff= RETURN PERIOD OF FLOOD IS 100 YEARS
RAINFALL INTENSITY FORMULA IS GIVEN
Ot SUMMARY OF SUBBASIN RUNOFF PREDICTIONS
TIME OF CONCENTRATION
MANHOLE BASIN OVERLAND GUTTER BASIN RAIN I PEAK FLOW
.1D NUMBER AREA = C To (MIN) Tf (MIN) Tc (MIN) INCH/HR CFS
----------------------------------------------------------------------
1.00 0.05 0.00 0.00 0.00 4.58 0.23
2.00 0.05 0.00 0.00 0.00 4.58 0.23
3.00 0.05 0.00 0.00 0.00 4.58 0.23
4.00 0.05 0.00 0.00 5.00 10.16 0.50
THE SHORTEST DESIGN RAINFALL DURATION 1S FIVE MINUTES
DENVER CRITERIA WAS NOT USED TO CHECK THE COMPUTATED Tc.
__= SUMMARY OF HYDRAULICS AT MANHOLES
MANHOLE CRTRBTING RAINFALL RAINFALL DESIGN GROUND WATER COMMENTS
ID NUMBER AREA 3 C DURATION INTENSITY PEAK FLOW ELEVATION ELEVATION
MINUTES INCH/HR, CFS FEET FEET
1.00 0.00 0.00 0.00 0.50 5044.00 5042.33 OE
2.00 0.15 12.02 3.39 0.50 5045.80 5042.34 OE
3.00 0.10 5.00 5.08 0.50 5045.40 5043.18 OE
4.00 0.05 5.00 10.16 0.50 5044.50 5043.35 OE
OK MEANS WATER ELEVATION IS LOWER THAN GROUND ELEVATION
6
SUMMARY OF SEWER HYDRAULICS
NOTE: THE GIVEN FLOW DEPTH -TO -SEWER SIZE RATIO= .8
-------------------------------------------------------------------------------
SEWER MANHOLE NUMBER SEWER REQUIRED SUGGESTED EXISTING
1D NUMBER UPSTREAM DNSTREAM SHAPE DIA(RISE) DIA(RISE) DIA(RISE) WIDTH
-------- ID NO. ID N0. (IN) (FT) (IN) (FT) (IN) (FT) (FT)
-- - ----------------------------------------------------------
1.00 2.00 1.00 ROUND 5.37 6.00 6.00 0.00
2.00 3.00 2.00 ROUND 5.37 6.00 6.00 0.00
3.00 4.00 3.00 ROUND 5.37 6.00 6.00 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
SEWER DESIGN FLOW NORMAL BORAML CRITIC CRITIC FULL FROUDE COMMENT
ID FLOW Q FULL Q DEPTH VLCITY DEPTH VLCITY VLCITY NO.
NUMBER CFS CPS FEET FPS FEET FPS FPS
-------------------------------------------------------------------------------
1.0 0.5 0.7 0.32 3.76 0.35 3.36 2.55 1.26 V-OK
2.0 0.5 0.7 0.32 3.76 0.35 3.36 2.55 1.26 V-OK
3.0 0.5 0.7 0.32 3.76 0.35 3.36 2.55 1.26 V-OK
FROUDE NUMBER=O INDICATES THAT A PRESSURED FLOW OCCURS
SEWER SLOPE INVERT ELEVATION BURIED DEPTH COMMENTS
ID NUMBER UPSTREAM DNSTREAM UPSTREAM DNSTREAM
3 (FT) (FT) (FT) (FT)
----------------------------------------------------------------------
1.00 0.85 5041.99 5041.83 3.31 1.67 OE
2.00 0.85 5042.83 5041.99 2.07 3.31 OE
3.00 0.85 5043.00 5042.83 1.00 2.07 OK
OE MEANS BURIED DEPTH IS GREATER THAN REQUIRED SOIL COVER OF 1 FEET
ttt SUMMARY OF HYDRAULIC GRADIENT LIKE ALONG SEWERS
SEWER SEWER SDRCHARGED CROWN ELEVATION WATER ELEVATION FLOW
ID NUMBER LENGTH LENGTH UPSTREAM DNSTREAM UPSTREAM DNSTREAM CONDITION
FEET FEET FEET FEET FEET FEET
-------------------------------------------------------------------------------
1.00 18.30 0.00 5042.49 5042.33 5042.34 5042.33 JUMP
2.00 99.21 0.00 5043.33 5042.49 5043.18 942.34 JUMP
3.00 20.07 0.00 5043.50 5043.33 5043.35 5043.18 JUMP
PRSS'ED=PRESSDRED FLOW; JUMP=POSSIBLE HYDRAULIC JUMP; SOBCR=SDBCRITICAL FLOW
I
0
' M SUMMARY OF ENERGY GRADIENT LINE ALONG SEVERS
'
UPST MANHOLE SEWER JUNCTURE LOSSES DOWNST
MANHOLE
SEWER MANHOLE ENERGY FRCTION BEND BEND LATERAL LATERAL MANHOLE
ENERGY
NO ID NO. ELEV FT FT K COEF LOSS FT E COEF LOSS FT ID
FT
-ID
- ---- -------- -------- -------- -------- ----------------------------------
1.0 2.00 5042.52 0.19 0.05 0.00 0.00 0.00 1.00
5042.33
2.0 3.00 5043.36 0.83 0.08 0.01 0.00 0.00 2.00
5042.52
'
3.0 4.00 5043.53 0.16 0.08 0.01 0.00 0.00 3.00
5043.36
BEND LOSS =BEND K= FLOWING FULL VHEAD IN SEWER.
LATERAL LOSS= OUTFLOW FULL VBEAD-JCT LOSS K=INFLOW FULL VHEAD
'
FRICTION LOSS=O MEANS IT IS NEGLIGIBLE OR POSSIBLE ERROR DOE TO JUMP.
FRICTION LOSS INCLUDES SEWER INVERT DROP AT MANHOLE
NOTICE: VBEAD DENOTES THE VELOCITY BEAD OF FULL FLOW CONDITION.
A MINIMUM JUCTION LOSS OF 0.05 FT WORLD BE INTRODUCED UNLESS
LATERAL K=O.
FRICTION LOSS WAS ESTIMATED BY BACKWATER CURVE COMPUTATIONS.
SUMMARY OF EARTH EXCAVATION VOLUME FOR COST ESTIMATE.
THE TRENCH SIDE SLOPE = 1
---------------------------------------------------------------------
MANHOLE GROUND INVERT MANHOLE
ID NUMBER ELEVATION ELEVATION HEIGHT
FT
-----------------F-------------------F-----------------------------------------
1.00 5044.00 5041.83 1.17
2.00 5045.80 5041.99 3.81
3.00 5045.40 5042.83 2.57
4.00 5044.50 5043.00 1.50
-------------------------------------------------------------------------------
SEWER UPST TRENCH WIDTH DNST TRENCH WIDTH TRENCH WALL
EARTH
ID NUMBER ON GROUND AT INVERT ON GROUND AT INVERT LENGTH THICKNESS
VOLUME
FT FT FT FT FT INCHES
-------------------------------------------------------------------------------
CUBIC YD
1.00 8.87 2.75 5.58 2.75 18.30 1.50
11.3
'
2.00 6.39 2.75 8.88 2.75 99.21 1.50
65.7
3.00 4.25 2.75 6.39 2.75 20.07 1.50
7.6
TOTAL EARTH VOLUME FOR SEWER TRENCHES = 84.60274 CUBIC YARDS
EARTH VOLUME WAS ESTIMATED TO HAVE
BOTTOM WIDTH=DIAMETER OR WIDTH OF SEWER + 2 = B
B=ONE FEET WHEN DIAMETER OR WIDTH <=48 INCHES
B=TWO FEET WHEN DIAMETER OR WIDTH >48 INCHES
IF BOTTOM. WIDTH <MINIMUM WIDTH, 2 FT, THE MINIMUM WIDTH WAS USED.
BACKFILL DEPTH UNDER SEWER WAS ASSUMED TO BE ONE FOOT
'
SEWER WALL THICKNESS=EQIVLNT DIAMATER 1N INCH/12 +1 IN INCHES
1
OFF -SITE SWALE DESIGN
Northern Engineering CLIENT JOB NO.
Services, Inc. PROJECT CALCULATIONS FOR
Fort Collins. Colorado 80521 MADE BY M-24oy DATE CHECKED BY DATE� SHEET_ OF
I
Triangular Channel Analysis & Design
Open Channel - Uniform flow
Worksheet Name: Landings P.U.D.
Comment: Capacity of Off -site Swale
Solve For Depth
Given Input Data:
Left Side Slope.. 4.00:1 (H:V)
Right Side Slope. 4.00:1 (H:V)
Manning's n...... 0.030
Channel Slope.... 0.0068 ft/ft
Discharge........ 9.40 cfs
Computed Results:
Depth............
Velocity.........
Flow Area........
Flow Top Width...
Wetted Perimeter.
Critical Depth...
Critical Slope...
Froude Number....
0.97 ft
2.48 f p s v S� �✓i , r. _-- _
3.79 sf
7.79 ft
8.03 ft
0.81 ft
0.0185 ft/ft
0.63 (flow is Subcritical)
Open Channel Flow Module, Version 3.42 (c) 1991.
Haestad Methods, Inc. * 37 Brookside Rd * Waterbury, Ct 06708
I
11
Triangular Channel Analysis & Design
Open Channel - Uniform flow
Worksheet Name: Landings P.U.D.
Comment: 100-Yr Velocity Check of Off -site Swale
Solve For Depth
Given Input Data:
Left Side Slope..
Right Side Slope.
Manning's n......
Channel Slope....
Discharge........
Computed Results:
Depth............
Velocity.........
Flow Area........
Flow Top Width...
Wetted Perimeter.
Critical Depth...
Critical Slope...
Froude Number....
4.00:1 (H:V)
4.00:1 (H:V)
0.030
0.0190 ft/ft
7.00 cfs
0.72 ft
3.38 fps
2.07 sf
5.75 ft
5.93 ft
0.72 ft
0.0192 ft/ft
0.99 (flow is Subcritical)
Open Channel Flow Module, Version 3.42 (c) 1991
Haestad Methods, Inc. * 37 Brookside Rd * Waterbury, Ct 06708
i
Q1
-r
4-
Y
4-
O
Q
N
O
O
Co
Ln
to
LA
Ln
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EROSION CONTROL CALCULATIONS
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S.
RAINFALL PERFORMANCE STANDARD EVALUATION
PROJECT: Landings Office Park P.U.D. STANDARD FORM A
COMPLETED BY: Mary B. Wohnrade DATE: June 20, 1995
Developed Erodibility Asb Lab Ssb Lb Sb PS(Table 8-A)
Sub -Basin Zone (ac) (ft) (%) (ft) (%) (%)
D1
Moderate
0.844
333
2.40
D5
0.450
257
4.67
D7
0.185
118
4.49
D8
0.052
80
4.69
D9
1.038
465
3.18
Total =
2.568
308
3.31
82.2
D4
Moderate
0.380
186
3.76
82.2
D2
Moderate
0.294
50
8.26
83.7
D3
Moderate
0.336
65
7.52
83.5
D6
Moderate
0.500
43
8.53
83.7
Lb = sum (Lsb x Asb) / sum Asb
Sb = sum (Ssb x Asb) / sum Asb
Performance Standard (PS) = See Table 5.1
CAW P5\DRAT NAGE\STNDFRMB. ERS
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CONSTRUCTION SEQUENCE
SEQUENCE FOR 1995— 96 COMPLETED BY: MBW DATE: SEPT 15, 1995
1995— 96
MONTH
UG
EP
T
OV
DEC
JAN
FEB
M
PR
MAY
JUNJJLY
OVERLOT GRADING:
ha
es'
I &
II
WIND EROSION CONTROL'
Soil Roughening
Perimeter Barger
Additional Barriers
VS5eeqgetsoetavlee Methods
WOtheont
RAINFALL EROSION
CONTROL STRUCTURAL:
Sediment Trap/Basin
Inlet Filters
Straw Barriers ,
Silt Fence. Barriers
Ph
ses'
1
11
Band q s
Bore oilg Preparation
Contour Furrows
Terracin
Aspholt�oncrete Paving
RipRop Outlet Control
pas
I
Pas
II
VEGETATIVE:
Permanent Seed Pic tin
Mulching%Sealant
Temporary Seed Planting
Sod Ins allatr n
has
I
Ph
ses'
18
II
P
ose
I
Iasi!
Netting�Mats%Blankets
Other
STRUCTURES: INSTALLED BY MAINTAINED BY
VEGETATION/MULCHING CONTRACTOR
DATE SUBMITTED: 05/22/95 APPROVED BY CITY OF FORT COLLINS ON
I
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I
I
EFFECTIVENESS CALCULATIONS
PROJECT: Landings Office Park P.U.D. STANDARD FORM B
COMPLETED BY: Mary B. Wohnrade DATE: June 20, 1995
Erosion Control Method
C-Factor
P-Factor_
Comment
Roads/Walks
0.01
1.00
All Basins
Hay Mulch
0.06
1.00
All Basins
Gravel Filter
1.00
0.80
Basin D4
Straw Bale Barriers
1.00
0.80
Basins' D5, D9
Established Grass
0.03
1.00
Pond D1
Silt Fence
1.00
0.50
Basins' D2, D3, D6
Sod Grass
0.01
1.00
All Basins
Major Performance Sub -Basin Area Calculations
Basin Standard (%) (Ac)
D1, D5 82.2
2.568 Roads/Walks = 1.20 ac
D7, D8, D9
Sod Grass = 0.409 ac
Hay Mulch = 0.738 ac
Established Grass = 0.221
Net C Factor = 1.20(0.01)+ 0.409(0.01)+0.738(0.06)
+0.221(0.03)/2.568 = 0.067
Net P Factor = 0.80
EFF = (1-(0.067 x 0.80))/100= 94.6%
D4 82.2
0.380 Roads/Walks = 0.217 ac
Sod Grass = 0.055 ac
Hay Mulch = 0.108 ac
Net C Factor = 0.217(0.01)+0.055(0.01)
+0.108(0.06)/0.380 = 0.0242
Net P Factor = 0.80
EFF = (1-(0.0242 x 0.80))/100=98.1%
D2 83.7
0.294 Roads/Walks = 0.156 ac
Sod Grass = 0.138 ac
Net C Factor = 0.156(0.01)+0.138(0.01)
/0.294 = 0.01
Net P Factor = 0.50
EFF = (1-(0.01 x o.50))/100=99.5%
BASINS' D3 AND D6 WILL ALSO HAVE AN EFF= 99.5%
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DESIGN CRITERIA
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Northern Engineering CuENT
JOB NO
SeMces, Inc. CALCULATIONS FOR
Fort Collins. Colorado 80521 MADE BY pAT�� / �, �y NECKED BY DATE SHEET
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DRAINAGE CRITERIA MANUAL
¢.
RIPRAP
Use Do instead of D whenever flow is supercritical in the barrel.
**Use Type L for a distance of 3D downstream.
FIGURE 5-7. RIPRAP EROSION PROTECTION AT CIRCULAR
CONDUIT OUTLET.
11-15-82
URBAN DRAINAGE 5 FLOOD CONTROL DISTRICT
I7I
1 53
Circular Channel Analysis & Design
Solved with Manning's Equation
Open Channel - Uniform flow
Worksheet Name: Landings P.U.D.
Comment: Storm Sewer Line D1
Solve For Actual Discharge
Given Input Data:
Diameter..........
Slope .............
Manning's n.......
Depth.............
Computed Results:
Discharge.........
Velocity..........
'
Flow Area.........
Critical Depth....
Critical Slope....
Percent Full......
Full Capacity.....
QMAX @.94D.
Froude Number.....
11
I
'1
1.25 ft
0.0045 ft/ft
0.010
1.18 ft
6.06 cfs
5.06 fps
1.20 sf
1.00 ft
0.0055 ft/ft
94.00 %
5.63 cfs
6.06 cfs
0.63 (flow is Subcritical)
Open Channel Flow Module, Version 3.42 (c) 1991
Haestad Methods, Inc. * 37 Brookside Rd * Waterbury, Ct 06708
I
19
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1
FINAL DRAINAGE REPORT
HEART SPECIAL*--IMPR. DISTRICT
CITY OF FO
COUNTY OF LARIMER
STATE OF COLORADO
DECEMBER, 1984
REVISED: JANUARY 1985
PROJECT NO.: 311.2
Prepared by:
Engineering Professionals, Inc.
2625 Redwing Rd., Suite 110
Fort Collins, CO 80526
(303) 226-3852
8
11
' INTRODUCTION
This final drainage report is submitted in conjunction with
construction drawings for Heart Special Improvement District
prepared by Engineering Professionals, Inc. The City of Fort
Collins "Storm Drainage Design Criteria and Construction
Standards" were used as guidelines for runoff calculations and
storm sewer system design.
SITE DESCRIPTION
Heart Special Improvement District is located in the West
half of Section 36, Township 7 North, Range 69 West of the Sixth
i" P.M. Proposed improvements consist of construction of portions
of JFR Parkway and Troutman Parkway, realignment of the Larimer
#2 Canal, construction of a 5-foot by 20-foot box culvert under
the intersection of JFR and Troutman Parkways, and construction
of water, sanitary sewer, and storm sewer utilities. Future
land use in the District will primarily be commercial and
business -related, although approximately 10 acres in the
southeast portion of the District is intended to be developed as
high -density residential. The District contains approximately
45.3 acres, is predominantly covered with native vegetation, and
slopes to the south and east at from .5 to 2%. The site is
bordered on the north and east by Boardwalk Drive, on the west
by business and residential properties, and on the south by
agricultural land. The Larimer #2 Canal crosses the site in a
general northeast -to -southwest direction.
IHISTORIC DRAINAGE
Before construction of the Landings and Whaler's Cove
residential areas, the portion of the site below the Larimer #2
Canal drained to the major basin thalweg to the south, while the
area above the Larimer #2 Canal discharged into the canal. At
present, the majority of the site drains into the Larimer #2
Canal, a portion drains south toward the basin thalweg, and the
remainder drains into an open channel leading to Harmony
Reservoir (see Figure 1). Estimated historic 2-year and 100-year
peak discharges into the Larimer #2 Canal from the site are 5.9
cfs and 20.5 cfs, respectively. Estimated 2-year and 100-year
historic peak discharges from the site area below the Larimer #2
11 Canal are 4.2 cfs and 15.5' cfs, respectively.
I
!!ASTER DRAINAGE
A report entitled "Master Storm Drainage Report for the
Landings P.U.D.," by Cornell Consulting Company recommended that
' areas above the Larimer #2 Canal be allowed to release storm
flows at the historic 2-year level directly to the Larimer #2
Canal. Those portions of the site below the Larimer #2 Canal,
with the exception of Troutman Parkway, were to drain into an
open channel running to Harmony Reservoir, as outlined in the
above report.
' DRAINAGE UNDER DEVELOPED CONDITIONS
'
City
of Fort Collins
Storm Drainage
Utility
staff has
recommended that the Larimer
#2 canal running
through
the site be
sized for
flows and
a total discharge of 240 cfs, 155
85 cfs of stormwater flows. Assuming
cfs of
only
irrigation
those areas
above the
canal and to the
east of College
Avenue,
(with the
exception of the Jetty P.U.D., which discharges to Harmony
Reservoir) contribute to stormwater discharge into the canal, the
allowable release rate per tributary acre is approximately 0.87
cfs per acre (see Figure 1). We request that the City of Fort
Collins require all future developers in this basin east of
College Avenue above the Larimer #2 canal to design and construct
facilities sized to detain the developed 100-year runoff volume
and release at a rate of 0.87 cfs per tributary acre.
' Curb inlet lengths were sized for the 10-year event
according to City of Fort Collins Drainage Design Criteria.
Storm sewers discharging from future building sites into curb
inlets were sized based on a detained release rate of .87 cfs per
acre summed with any offsite discharge. The remainder of the
storm sewer system from curb inlets to the Larimer #2 Canal were
sized to handle the larger of the peak discharge from the 10-year
street runoff intercepted by the curb inlets, or 10-year peak
discharge from the total tributary area assuming a time of
concentration of 20 minutes.
'
According
to recommendations made in the Cornell
Report,
those portions
of the District below the Larimer #2 Canal
(basins
'
H, I, and M;
see map) were to drain undetained to
Harmony
Reservoir via
a grass lined, trapezoidal channel.
Due to
circumstances unforeseen during preparation of the Cornell
Report, we propose that detention facilities sufficient to detain
the 100-yearevent and releasing onto "Somerset" at the 2-year
historic rate be constructed by future developers of basins H, I,
and M.
An undeveloped area of 3.6 acres at the Northwest corner of
Landings Drive and Boardwalk discharges under Boardwalk via curb
inlet and culvert onto Basin E. The inlet and culvert were sized
by others based on undeveloped conditions; future developers of
that parcel will need to detain on -site to limit future
discharges to .87 cfs per acre, as this area historically
' discharged into the Larimer #2 Canal. We assumed that these
undeveloped flows passed through Heart S.I.D. undetained to the
' Larimer #2 Canal.
' ENGINEERING PROFESSIONALS, INC.
Jonathan B. Howard
' Michael N. Schmid, P.E.
' JBH:psm
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Ct•• ,tl• • • a i• °• / Al
' August 10, 1993
Mr. Glen Schlueter
City of Fort Collins
Stormwater Department
235 Mathews, P.O. Box 580
Fort Collins, CO 80522-0580
1 Re: ShopKo P.U.D./JFK Parkway Oversizing
Project No. 10-724-000
Dear Mr. Schlueter:
' We are writing this letter to address the drainage facilities associated with the oversizing of
the JFK Parkway adjacent to the ShopKo P.U.D. The City Engineering Department has
' indicated that ShopKo will be responsible for designing and constructing 100 L.F. of full
width (70 feet FL -FL) asphalt and the associated curb and gutter on the east side of JFK
Parkway at the intersection with Boardwalk Drive. From this point, a temporary asphalt
' taper will be constructed to the north to end in a 35-foot paved roadway.
On June 21, 1993, myself and Rich Dvorak (TST, Inc.) met with you, Mike Herzig and
Kerrie Ashbeck of the Engineering Department to discuss the particulars of this portion of
the ShopKo site. We discussed several options for dealing with the drainage issues and
_ settled on the following:
1. The east pond has approximately 2.5 feet of freeboard so it has some excess capacity.
f 2. If we can assume that the site on the east side of JFK Parkway will be graded such
that it will drain away from the intersection, a permanent curb inlet can be installed
directly opposite Inlet #5 shown on the ShopKo P.U.D. Utility Plans.
3. If the pond has the excess capacity and the pipe sizes, as designed in the Drainage
' Report for the ShopKo P.U.D., do not increase, the new inlet could be permanently
tied to ShopKo Inlet #5.
' 4. All of the above would be contingent on the site to the east not allowing any more
runoff to reach the new inlet than what would be expected from a sub -basin covering
the area from the high point on JFK south to Boardwalk, and from the centerline of
JFK to the east right-of-way line.
Boardwalk Drive slopes downhill to the west as it crosses JFK Parkway. Boardwalk has no
crown, so runoff sheetflows across the street from north to south. There is an existing curb
and gutter on the north side of the street and the gutter will carry nuisance flows west to
College Avenue: Mike Herzig indicated that a cross pan in JFK is not an option, so the
nuisance flows will have to be routed around the curb return and into the new inlet.
TST, INC. 748 Whalers Way • Building D 102 Inverness Terrace East
' Consulting Engineers Fort Collins. CO 80525 Englewood, CO 80112
(303)226-0557 (303)792.0557
Metro Denver(303) 595.9103 FAX (303)792.9489
FAX (303) 226-0204
TST, INC.
Mr. Glen Schlueter
August 10, 1993
'
Page 2
I
fl
Our analysis was based on the previously mentioned scenario. We assumed a sub -basin
identical to Sub -basin L in the Final Drainage Report for the ShopKo P.U.D. and will call
this Sub -basin Ll. Runoff was calculated using the rational method and peaks for the 10-
year and 100-year storms were derived. Although the proposed inlet, Inlet #5A, is
technically in a sump, there is only a minimal ponding. depth available because of the lack
of a crown in Boardwalk, so the inlet was analyzed as an on -grade inlet. Our analysis
indicates a 17-foot inlet would be required for 100 % interception; however, we are
suggesting a 15-foot inlet be used. The available ponding depth should be enough to keep
the passing flow (less than 0.50 cfs) from entering Boardwalk. The proposed Pipeline B1
linking Inlet ##5A and Inlet #5 was calculated manually using a variation of Manning's
Equation. A 15" diameter RCP will be more than adequate. Line B of the ShopKo P.U.D.
Utility Plans was regraded to accommodate the connection of Inlets #5 and #5A and the
capacity was re -checked. It turned out that the original 15" pipe would suffice, but the
contractor needed to order the pipe some time ago, so as a worst case scenario, we indicated
a pipe size based on a minimum grade which is a 24" RCP. All of the pipes down stream
of Inlet #1 were adequate to carry the additional 2.76 cfs. The additional flow into the
ShopKo P.U.D. east pond was analyzed and results in a peak inflow of 43.17 cfs during the
100-year storm and leaves 2.0 feet of freeboard.
We believe this system satisfies all of the City of Fort Collins Stormwater Utility Design
Criteria. The following pages show the calculations which support the information we have
previously presented in this letter. It should be noted that the property to the north, when
developed, can direct no more than 2.76 cfs to this inlet during the 100-year storm if it is
to remain connected to the ShopKo system.
If you have any questions or comments, please feel free to contact us.
Sincerely,
' TST, INC., CONSULTING ENGINEERS
' tephen F. Human, P.E.
' DL/lc
1
1
L
n
Dave Lindsay
0
No Text
TARANTO, STANTON 3 TAGGE (OZ
Consulting Engineers
CLIENT JOC[ /FiGr%VJOBNO.
PROJECT-5L'201�ZR CALCULATION$FOR 5cA961
t5/'-U/%1— MADE BY'/�%L DATE `'�J3 CHECKED SY DATE SHEETOF
UN nFF
G0507r}Bt
� ( i
FINAL DRAINAGE REPORT
FOR
HIGH POINTE P.U.D.
LOCATED AT
•-BOARDWALK DRIVE & LANDINGS DRIVE
FORT COLLINS, COLORADO
REVISED 8/22/89
I
TO BE DEVELOPED:BY:
FAIRFIELD HOMES
LAKEWOOD, COLORADO
11
IPREPARED BY: PARSONS & ASSOCIATES
' 432 Link Lane Plaza
IFort:Collins, Colorado 80524
(303) 221-2400
PROJECT NO. 89.10 JET
1
�r
FINAL DRAINAGE REPORT
FOR THE HIGH POINTE P.U.D.
INTRODUCTION
This drainage investigation has been performed for the
purpose of providing design information for the development of the
High Pointe P.J.D., a residential development to be located at the
northeast corner of the intersection of Boardwalk°Drive and the
Landings Drive, Fort Collins, Colorado. The City of Fort Collins
"Storm Drainage Design •Criteria and Construction Standards" was
used as a basis for guidelines and criteria throughout this
investigation.
SITE DESCRIPTION
The High Pointe P:U.D. is situated in the West one-half of
Section 36, Township 7 North, Range 69 West of the 6th Principal
Meridian, City of Fort Collins, Larimer County, Colorado. The
site is bounded by Landings Drive on the west, Boardwalk Drive on
the south and by Larimer County Canal No. 2 on the north and east
side. The site contains approximately 12.15 acres. Eighteen (18)
single family residential lots along with open space are proposed
for. the site. .
HISTORIC DRAINAGE
A ridge line separates existing flows on the site with
approximately 1/2 of the site draining northerly to Larimer County
Canal No. 2 and approximately 1/2 of the site draining easterly to
'Canal No. 2. Approximately, 1.38 'cfs flows to Canal No. 2
downstream of the existing check structure.
An area of 0.68 acres to the south of the Landings Drive
flows to this site (2.75' cfs), and will be directed through
detention Pond "A" and on through to Larimer County Canal No. 2.
DEVELOPED CONDITIONS
In compliance with, the Master Drainage Study prepared by
Cornell Consulting Company for The Landings P.U.D. dated January
1979, the release rate to.the Larimer County Canal No. 2 will be
restricted to the 2-year historic rate and detention will be
provided on -site to accommodate the 100-year developed flows.
Runoff coefficient used for the developed site is 0.45. Detention
has been provided for a portion of Landings Drive and Boardwalk
Drive which are. adjacent' to the site., Total release from this
site into Canal No. 2 is 6.09 cfs. (2.09 cfs from Pond A,•1.25
cfs from Pond B,& 2.75 cfs from off -site area-0-1) Detention
required for this site is-49,000 cubic feet. (18,200 cubic feet
in Pond:A, 30,800 cubic feet in Pond B). Landscaping ponds are to
be lined, and water supplied to be domestic. All required permits
shall be acquired from the state. No water from ponds is to be
released from landscaping .ponds to the storm drainage system.
Ground water is 4.0 to 4.5 feet below finished grade at Pond B and
1 8.0 feet below finished grade at Pond A.
r. There exists a check structure which diverts flows fromlthecanal to Warren Lake_ From the previously approved Jetty P.U.D.
-plans dated January,"1986. ..There was 1.85 cfs released into Canal
■ .y .:.No.' 2 downstream of :the .check :structure.- -In the Heart "Special
® :;4-Aiproveient'District and "in the improvement of Canal `No."2;
.;.release rates' -..for all areas draining to Canal No. 2 have been
limited to"0.87 cfs per developed acre . When Fort Collins Retail
Center .was `developed, runoff from 4.03 acres was piped :under"the
canal and allowed to outf all in an open :field to the east. At
0.87 :'cfs ^�per,.Z_acre (and 4.02 -acres), this should allow an
"'''additional 3.5 cfs to be released into Canal No. 2 downstream of
the check structure without impacting anticipated design flows.
The present design of this 'site. allows for the release of
1.38 cfs downstream of the check structure, to match the
historical condition. This is 0.47 cfs less'than the previously
.' approved plan of this site and is.2.12 cfs less than the unused
capacity of the Canal from the Fort Collins Retail Center.
W
IA-9224.ESM
' DESCRIPTION FOR DRAINAGE EASEMENT
That portion of the West Half of Section 36, Township 7 North,
' Range 69 West of the 6th P.M., Larimer County, Colorado, described
as follows:
Considering the West line of the Northwest Quarter of Section 36 as
bearing North and South and with all bearings contained herein
relative thereto.
' Commencing at the Northwest corner of said Section 36; thence South
28"44132" East 2772.12 feet to the intersection of a 20-inch CMP
drainage pipe with the Southerly right-of-way line of Boardwalk
Drive and the True Point of Beginning of the centerline of a 10-
foot drainage easement. Thence along said drainage easement
centerline South 26"4410011 East 22.54 feet; thence South 25"131301'
East 18.58 feet to the beginning of a tangent curve concave to the
Northwest, having a central angle of 53"31'07" and a radius of
200.00 feet; thence Southwesterly along the arc of said curve and
continuing along said easement centerline 186.82 feet to the
beginning of a tangent curve concave to the Southeast, having a
central angle of 27"511'58" and a radius of 161.60 feet; thence
Southwesterly along the arc of said curve and continuing along said
easement centerline 78.60 feet; thence tangent from said curve and
continuing along said easement centerline South 00"251139" West
480.00 feet to the approximate centerline of the Larimer County
Canal No. 2 and the terminus of said easement centerline. The
sidelines of said easement to be shortened or lengthened to meet
with said Southerly right-of-way line of Boardwalk Drive.
r
I
I
I
I
I
I
' LICENSE TO ENTER PRIVATE PROPERTY
THE CITY OF FORT COLLINS, a Colorado Municipal Corporation, is
' the owner of certain real property in Larimer county, Colorado,
legally described in that Treasurer's Deed recorded at Reception
Number 02066317 in the Larimer County Records, does hereby grant
permission to Lagunitas Landings. Inc., its employees, authorized
agents, contractors, and assigns to enter the property shown on
Exhibit "A", attached hereto and incorporated herein by this
reference, for the sole purpose of constructing a storm drainage
Swale in accordance with the Utility Plans for Landings Office Park
P.U.D., dated July 7, 1995.
' As a condition of granting this license, the Grantee agrees
that upon completion of these construction activities remaining portion of the above , the
-described property will be restored
to its former condition at the Grantee's expense.
THE CITY OF FORT COLLINS, a Colorado
Municipal Corporation
' Date: 3 4City
ana
ATTEST:
City C r `
rA PROVED A8 TO ORM;
Ass stant City Atto ney
GRANTEE:
LAGUNITAS LANDINGS• INC.
Date:
ATTEST:
Title:
1
p.01
SEP-S1-`�3 MON 13:36
July 14, 1995
City of Fort Collins
281 K College
Fort Collins, CO 80525
RE: Landings Office Park Storm Drainage
Dear sirs:
We have looked at the drainage plann for hhiproject
pro project and
are our n agreement with how
the proposed storm water Will proceed
One exception we have is that we ditch and that the grassy p4� be constructedie to withtnpr putorog out, as
be continued directly into th
shown.
Furthermore, we agree to indicate our approval to the landings Office Park storm
drainage plan by our signature on the plat.
Yours truly,
ehn Strachan
President, Ladmer Canal #2
EXHIBIT A
DRAINAGE EASEMENT
rtw
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-Ar C.M.P.
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NOTE: THIS DRAWING IS NOT A "LAND SURVEY PLAT" AS DEFINED BY COLORADO REVISED STATUTES
38-51-107 AND SURVEY MONUMENTS WERE NOT SET FOR THIS PROJECT, IT IS FOR PRELIMINARY
INFORMATION ONLY.
SCALE
DATE
I DRAWN
I REVISED
I FILE NO.
EXHIBIT
SHEET
1'W100�
... CP-1/
RB
A9130EX1
LANDSTAR SURVEYING INC. 1327 N. Uncoln Ave. • Loveland, CO 80537 • (303) 067, 420� • fA 3�. 687-71b1;1
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aFF-
NORTHERN ENGINEERING SERVICESI PFOjEC`
420 SOUTH HOMES SUITE 202, FT. COLLINS, COLORADO 80521 I SCSIALEe 4
OECNEF
(303) 221-4155
tlfi
OCT 3 0 1995 t 5
P DS
ISO Iy,Fp{s o15. RCP ^zvl,4
BKanT P2E1 - W39:zs PR(W. IT
W AT OUTLET
�\ TO LAF ER Ca
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SA2/ CT
TO W5)- 3tI55 U.F.
v� SECTION A -A
x.us.
#8 CANAL
10' OFF -SHE MMW4 WEMFNT
HE
2.0
NOTICE IT L ERING
sTOIM1TATIR Pam v N 116 1.5'
PAIIRIIIJ AlOIANO A
NA 0l 131 �I..
(2T WGN LETTERING) Ir
�iCL /ice
LEGEND
-��
EXISIMG STORM SEWER
«�
PROPOSED STORM SEWER
Exlenw STDPY uRmwE INLET
�.+
PROPYRA) WNW DW.IWGE INLET
I1111111111111111
AWN ORO(40F EUM
-'
EX5N11CW FLOW PATTERN
-55-
FROWNED Comm
1
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MFA N1 4GRES
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GRAPHIC SCALE
30
�Eie�l ao
DITCH CO, APPROVAL BLOCK
LARWER CANAL CO. .
CANAL NO. 2
�c
CITY APPROVAL BLOCK:
CITY OF FORT COLLINS„ COLORADO
UTILITY PLAN APPROVAL
wPR�Xw
WE HE& AM dWR
m w ex�muw '- wT-
CNECXm BYr
G xO. M3M'OIMi wl
m M w
IT
CHECKED W.
IDINGS OFFICE PARK P.U.D.
FINAL
DRAINAGE PLAN