HomeMy WebLinkAboutReports - Drainage - 06/26/2025FINAL DRAINAGE REPORT
FOR
COLLEGE & TRILBY MULTI-FAMILY
COMMUNITY
Prepared For:
ZOCAL COMMUNITY DEVELOPMENT
455 SHERMAN STREET, SUITE 250
COLORADO, DENVER 80020
KOLBY O’HERRON
(303) 820-8611
June 26th 2025
Project No. 39823.00
Prepared By:
JR Engineering, LLC
2900 South College Avenue, Suite 1A
Fort Collins, CO 80525
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TABLE OF CONTENTS
TABLE OF CONTENTS ......................................................................................................................... ii
APPENDIX ..................................................................................................................................... iii
Engineer’s Certification Block ........................................................................................................... iv
GENERAL DESCRIPTION AND LOCATION ............................................................................................ 1
LOCATION ..................................................................................................................................... 1
DESCRIPTION OF PROPERTY .......................................................................................................... 1
MASTER DRAINAGE BASIN DESCRIPTION ....................................................................................... 2
FLOODPLAIN SUBMITTAL REQUIREMENTS ..................................................................................... 3
DRAINAGE BASINS AND SUB-BASINS ................................................................................................. 3
MAJOR BASINS AND SUB-BASINS ................................................................................................... 3
EXISTING SUB-BASIN DESCRIPTION ................................................................................................ 4
EXISTING OFFSITE DRAINAGE BASINS ............................................................................................ 4
PROPOSED SUB-BASINS DESCRIPTIONS ......................................................................................... 5
ONSITE SWMM SUB-BASINS DESCRIPTIONS .................................................................................. 9
OFFSITE SWMM SUB-BASINS DESCRIPTIONS ................................................................................. 9
PROJECT DESCRIPTION .................................................................................................................... 14
PROJECT DESCRIPTION ................................................................................................................ 14
PROPOSED DRAINAGE FACILITIES .................................................................................................... 14
GENERAL CONCEPT ..................................................................................................................... 14
WATER QUALITY/ DETENTION FACILITIES .................................................................................... 15
LOW IMPACT DEVELOPMENT ...................................................................................................... 16
DRAINAGE DESIGN CRITERIA ........................................................................................................... 16
REGULATIONS ............................................................................................................................. 16
FOUR-STEP PROCESS TO PROTECT RECEIVING WATERS ............................................................... 16
DEVELOPMENT CRITERIA REFERENCE AND CONSTRAINTS ........................................................... 18
HYDROLOGIC CRITERIA ................................................................................................................ 18
HYDRAULIC CRITERIA ................................................................................................................... 19
FLOODPLAIN REGULATIONS COMPLIANCE ................................................................................... 20
MODIFICATIONS OF CRITERIA ...................................................................................................... 20
EROSION CONTROL ..................................................................................................................... 20
CONCLUSIONS ................................................................................................................................. 20
COMPLIANCE WITH STANDARDS ................................................................................................. 20
DRAINAGE CONCEPT ................................................................................................................... 21
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APPENDIX
Appendix A – Figures
Appendix B – Hydrologic Calculations
Appendix C – Hydraulic Calculations
Appendix D – Water Quality Calculations
Appendix E – Reference
Appendix F – Maps
Appendix G – LID Exhibit
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Engineer’s Certification Block
I hereby attest that this report for the final drainage design for the College & Trilby Multi-Family
Community was prepared by me or under my direct supervision, in accordance with the provisions of the
Fort Collins Stormwater Criteria Manual. I understand that the City of Fort Collins does not and will not
assume liability for drainage facilities designed by others.
Joseph M. Frank, PE
Registered Professional Engineer
State of Colorado No. 53399
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GENERAL DESCRIPTION AND LOCATION
LOCATION
The site is located in The Southeast Quarter of Section 11, Township 6 North, Range 69 West of the 6th
P.M. in the City of Fort Collins, Larimer County, Colorado. More specifically, the site is a 39.1803 acre
property that is currently undeveloped. The site borders College Ave to the East, to the South, the Site
Borders Trilby Road, South Gate Church, and a right in and right out with access to Ziggy's Coffee. To
the west, the site borders a detention pond that controls runoff for the First Free Will Baptist Church,
the Skyview South First Filing Subdivision, and a social services organization owned by Foothills Gateway
Inc. To the north, the site borders Hazel Self Storage, two current vacant parcels of land, and a portion
of Skyview Drive.
DESCRIPTION OF PROPERTY
The site generally drains west to east at a 10% to 4% slope. The majority of the site is undeveloped and
has several existing farm buildings scattered throughout the site. There are two existing culverts crossings
under College Avenue along the eastern boundary of the subject property. The Two existing culverts
drain from the site east under College Avenue. The two crossings are identified as south and north. The
north crossing is a 48" pipe that gets downsized to a 30" pipe downstream. The south crossing is a 24"
pipe. College Avenue creates two inadvertent detention ponds on the subject property due to
attenuation/ponding of storm runoff. The inverts of the culverts are such that standing water remains after
rainfall events, creating wetland areas on the site. The site is located in the Fossil Creek Basin, specifically
within the Stone Creek sub-Basin. The Stone Creek master drainage plans identify these two inadvertent
detention areas and specify that these be preserved with the future development of the site. The North
Loudon Ditch and Reservoir Company has a 30” gravity irrigation line that goes through the site adjacent
and along the northern boundary of the site. The site currently has a small shed and gravel access road;
the majority of the site is primarily vacant with native grass. The Natural Resources Conservation Service
(NRCS) soil survey shows that the majority of the soils on site are composed of type B soils, which have
a mild infiltration and runoff rate. The remaining site is made up of Type C and D soils, which are
characterized by a lower infiltration rate and corresponding higher runoff rates. For additional information,
refer to the NRCS soil map within Appendix A of this report.
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MASTER DRAINAGE BASIN DESCRIPTION
The site is located in the Fossil Creek Basin, specifically within the Stone Creek sub-Basin. The Stone
Creek Basin - Selected Plan of Improvements", Icon, September 2018 calls out two areas for onsite water
quality and detention. The Stone Creek master plan specifies that a smaller pond be built near the existing
right in and right out by Ziggy's Coffee and College Ave. Currently, that site drains through a 24" RCP
and outfalls across College Ave. The smaller pond will have a riprap-lined overflow channel that will outfall
north into the larger pond. The City of Fort Collins has two options for detaining runoff on the site.
Option A – construct an overflow channel between the two detention ponds and upsize the northern
30" pipe downstream of the 48" outfall to a 48" pipe. This option significantly increases the allowed release
rate onsite and lowers the required detention volume.Option B –the onsite overflow channel is not
built/ or built, and the existing 30" RCP storm pipe is not upsized. With each option, the proposed project
will need to be in continuity with the City's Stone Creek SWMM model, and the peak release rate for
either option is to not be exceeded. Wilson and Company is currently working on the capital
improvements for the College and Trilby intersection, the City's Stone Creek SWMM model, and is
working on modifying the design recommendations called out in the 2018 Stone Creek Master Plan by
Icon Engineering to treat and detain storm water for the College and Trilby intersection improvements.
JR Engineering has incorporated the drainage improvement from College and Trilby into the site by
following the general recommendations from the Wilson and Company's design and the 2018 Stone Creek
Master Plan. JR Engineering is proposing that the smaller pond (P366) will be a water quality pond, an
overflow channel will be built, and the runoff will be detained in the larger pond (P363), but the 30" RCP
will not be upsized to a 48" RCP. Currently, the site is zoned as general commercial, but the site will be
re-purposed as a medium-density mixed-use neighborhood district. The North Loudon Ditch that goes
along the northern portion of the site is not anticipated to influence the drainage on site since it is currently
piped in a 30” RCP gravity line throughout the site.
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FLOODPLAIN SUBMITTAL REQUIREMENTS
The site is on FEMA FIRM panels 08069C1200F and 08069C1000F. The flood map for this location has a
status of "not printed". This means that the entire area of the panel is in a single flood zone, so FEMA
chose to economize and not create a printable image for this location. The site lies within FEMA Zone X,
areas which are determined to be outside the 0.2% annual chance floodplain. The site is not located within
a FEMA regulated floodplain, as shown in Appendix A in the FEMA attachments. The site is also not located
in the City of Fort Collins Floodplain, as shown in Appendix A in the City of Fort Collins Flood map.
DRAINAGE BASINS AND SUB-BASINS
MAJOR BASINS AND SUB-BASINS
The College and Trilby site is 39.1803 acres; the site will be developed into a multi-family residential
community with a recreation facility and will include onsite and offsite detention. The site is located in the
Fossil Creek basin. The Fossil Creek drainage basin extends along the south end of Fort Collins, from the
foothills across Interstate 25 past CR 5. It encompasses 32 square miles in the City of Fort Collins and
Larimer County. More specifically, the site is in the Stone Creek sub-basin of the Fossil Creek Tributary.
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EXISTING SUB-BASIN DESCRIPTION
The existing site’s hydrology was modeled within the 2018 Stone Creek basin master plan. EPA
SWMM was used to model the hydrology of the site. Currently, the City has accepted an updated
hydrologic model for the Stone Creek master plan after some inaccuracies were found when
Wilson and Company modeled the College and Trilby Capital Improvements for the site. The
site is anticipated to be constructed after capital improvements for the College and Trilby
Intersection have been made. JR Engineering is currently referencing the SC_100Yearprop
SWMM model as the existing conditions model.
This model includes the proposed drainage and storm system improvements, basin modifications,
and increased imperviousness due to the College and Trilby intersection improvements by
Wilson and Company, which are anticipated to be in place while the College & Trilby Multi-Family
Community is developed.
EXISTING OFFSITE DRAINAGE BASINS
Currently, the site collects offsite runoff from three locations: Runoff from the southern portion
of West Trilby Road drains onto the site via a CMP FES that crosses Trilby Road and drains
directly onto the site. Runoff from the Northern portion of Trilby Road drains onto the site via
a grass swale in confluence with upstream runoff, as shown in the offsite SWMM Map by Wilson
and Company within Appendix E. An existing drainage pan goes south to north in the backyards
of Skyview South First Filing as shown in the Trilby College Ex-Drainage Exhibit in Appendix G.
The runoff then goes offsite to an adjacent swale along Gateway Center Drive. In the 100-year
event, it’s anticipated that the runoff will overflow within the back of the yards. The capacity of
the existing drainage pan has been modeled in SWMM, and the capacity is shown in Appendix F
of this report in the Drainage Report on typical cross section AA.
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PROPOSED SUB-BASINS DESCRIPTIONS
Basin A1, 1.90 acres and 16 % impervious, is composed of open space, a proposed walk, and a
swale where runoff will be conveyed to design point 1a, where it will drain onto Rover Way via
a chase drain.
Basin A2, 1.79 acres and 51.9% impervious, is composed of multi-family residential units and an
alley. The runoff from this basin will be conveyed to an inlet at design point 2a.
Basin A3, 1.62 acres and 38% impervious, is composed of multi-family duplex residential units,
paved walks and paved driveways, and a residential local street Rover Way. The runoff from this
basin goes to design point 4a at an on-grade inlet.
Basin A4, 0.42 acres and 59.3% impervious, is composed of a local residential street, paved walk,
and paved driveways. The runoff from this basin goes to design point 5a at an on-grade inlet.
Basin A5, 0.75 acres and 69.0% impervious. This basin is composed of a collector Street Mars,
paved walk, and multi-family residential units. The runoff from this basin goes to an on-grade inlet
at design point 6a.
Basin A6, 0.47 acres and 73.5% impervious, is composed of a collector street Mars, paved walk.
The runoff from this basin goes to an on-grade inlet at design point 7a.
Basin A7, 1.26 acres and 65.0% impervious, is composed of a collector street Mars, paved walk,
and multi-family residential units. The runoff from this basin goes to an on-grade inlet at design
point 8a.
Basin A8, 0.30 acres and 65.6% impervious this basin is composed of a collector street Mars,
paved walk, and paved driveways. The runoff from this basin goes to an on-grade inlet at design
point 9a.
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Basin A9, 0.18 acres and 65.7% impervious, is composed of a collector street Mars, paved walk.
The runoff from this basin goes to an on-grade inlet at design point 10a.
Basin B1, 0.63 acres and 76.3% impervious, comprises a residential alley, multi-family residential
units, and paved driveways. The runoff from this basin drains to design point 1b at a sump inlet.
Basin B2, 1.17 acres and 7.0% impervious, comprises open space and a side swale that runs
adjacent to the property line. The runoff from this basin drain into a type D sump inlet at design
point 2b in confluence with upstream runoff from the capital improvements of Trilby College.
Basin C1.1, 3.82 acres and 4.5% impervious, comprised of residential duplex units, paved walks
and paved driveways, and a local residential street – Rover Way. The runoff from this basin drains
into an on-grade inlet at design point 1.1C.
Basin C1.2, 0.72 acres and 38.1% impervious, comprised of residential multi-family units, paved
walks and paved driveways, and a local residential street – Rover Way. The runoff from this basin
drains into an on-grade inlet at design point 1.2C.
Basin C1.3, 0.18 acres and 66.2% impervious, comprised of residential duplex units, paved walks
and paved driveways, and a local residential street - Rover Way. The runoff from this basin drains
into an on-grade inlet at design point 1.3C.
Basin C2, 1.12 acres and 41.6% impervious, is composed of paved walk and paved and a local
residential street - Rover Way. The runoff from this basin drains into an on-grade inlet at design
point 2C.
Basin C3, 2.22 acres and 70.2% impervious is composed of paved driveways, a paved local
residential alley, onsite park spaces, and multi-family residential units. The runoff from this basin
drains into an on-grade inlet at design point 3a.
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Basin C4.1, 0.82 acres and 67.5% impervious, is composed of residential multi-family units, walks,
and a local collector, Mars Drive. Runoff from this basin drains to a on-grade inlet at design point
4c.
Basin C4.2, 1.76 acres and 52.1% impervious, is composed of residential multi-family units, walks,
and a local collector, Mars Drive. Runoff from this basin drains to a sump inlet at design point 4c.
Basin C5, 1.34 acres and 65.0% impervious, is composed of residential multi-family units, walk,
and a local collector Mars Drive. Runoff from this basin drains to a sump inlet at design point 5c.
Basin D1, 0.29 acres and 81.4% impervious, is composed of a local residential street – Stellar
Drive and paved walk. The runoff from this basin drains to a sump inlet at design point d1.
Basin D2, 0.50 acres and 67.5% impervious is comprised of a local residential street –Stellar Drive
and paved walk. The runoff from this basin drains to a sump inlet at design point d2.
Basin E1, 0.42 acres and 81.3% impervious is comprised of a local residential alley, and multi-
family residential units. The runoff for this basin will be treated for water quality in pond P366.
Basin E2, 0.73 acres and 78.1% impervious is comprised of a road (Lunar Court) and a residential
Cul-de-Sac. Runoff from this basin will drain into a sump inlet and will be treated for water quality
in Pond 366.
Basin E3, 0.23 acres and 78.1% impervious is comprised of a private parking lot. The runoff from
this basin drains to design point 3e.
Basin E4, 0.17 acres and 62.6% impervious is comprised of a recreation facility. Runoff from this
basin drains directly into the adjacent water quality pond P366.
Basin E5, 0.38 acres and 37.4% impervious is comprised of a recreation facility. Runoff from this
basin drains directly into the water quality pond P366.
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Basin E6 0.86 acres and 6.3% impervious is comprised of the water quality detention pond P366.
Basin F1, 1.20 acres and 31.9% impervious, is composed of the overflow channel between pond
P366 and pond P363, as shown within section CC on the drainage maps
Basin OF1, 0.53 acres and 12.2% impervious, is composed of an overflow swale that captures
runoff from Skyview South, First Filing. Runoff in the overflow swale is routed to detention pond
P363.
Basin G1, 1.49 acres and 74.0% impervious, is composed of a residential alley, paved walk, paved
driveways, and multi-family residential units. The runoff from this basin drains to an on-grade inlet
within the alley at design point 1g.
Basin G2, 0.62 acres and 83.1% impervious. This basin is composed of a residential alley, paved
driveways, and multi-family residential units. The runoff from this basin drains to an on-grade inlet
at design point 2g.
Basin G3 has 1.06 acres, and 56.8% is impervious. This basin is composed of walks and residential
units. The runoff from this basin drains to a series of inlets represented by design point 3g.
Basin G4, 0.82 acres and 76.6% impervious is composed of residential alleys, paved driveways,
and multi-family residential units. The runoff from this basin drains to a sump inlet at design point
4g.
Basin H1 has 5.81 acres and is 7.3% impervious. This basin is composed of the detention facility
P363 for the site. Runoff from this basin drains and is released to an outlet structure, where it
goes directly east of the site under College Ave to the Prairie Dog Meadows Natural Area.
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ONSITE SWMM SUB-BASINS DESCRIPTIONS
Basin CT-1, 24.68 Acres and 53.4% impervious is composed the College & Trilby Multi-Family
development. Runoff from this basin will be treated for water quality in the ADS isolator rows.
Basin CT-2, 5.37 Acres and 45.7% impervious is composed the College & Trilby Multi-Family
development, recreation center and onsite water quality pond P366. The conveyance between
Pond P366 and Pond P363 is both channelized and piped in events greater than the 25 year and
the channel will receive flow from the overflow weir. In events under the 25 year the runoff will
be piped.
Basin CT-3, 1.20 Acres and 31.7% impervious is composed of the overflow channel and adjacent
lots. The water quality for this basin will be treated for water quality in the drainage channel as a
grass buffer for water quality treatment. This is shown as basin F1 on the rational drainage maps
F1.
Basin CT-4 (H1), 5.81 Acres and 7.3% impervious is composed of pond P363. Runoff from the
townhomes adjacent to the pond will be treated for water quality as they drain down into the
pond via a grass buffer. This is shown as basin H1 on the rational drainage maps.
Basin OF1, 0.53 Acres and 34.3% impervious is composed of the overflow channel and walk on
the western boundary of the site.
The conveyance between Pond P366 and Pond P363 is both channelized and piped in events
greater than the 25 year. In events under the 25 year the runoff will be piped.
OFFSITE SWMM SUB-BASINS DESCRIPTIONS
The offsite basins delineated by Wilson and Company are shown in Appendix E. The comprehensive
proposed drainage map and SWMM map are shown in Appendix F. The offsite basins are part of the Stone
Creek master plan and have recently been updated to incorporate the College and Trilby Intersection
improvements by Wilson and Company in February of 2024.
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The existing onsite Basins B820 and B910 have been removed and replaced with additional sub
basin to represent the site and the frontage for the site on W Trilby Road and South College
Ave. These new basin are represent by basins CT-1 through CT04, OS1- OS6 and OF1.
The offsite basins B930, B840, and B850 have been modified to conform to the proposed site
grading and observed offsite drainage patterns. In addition, since B910B was part of the Trilby
frontage and part of the existing site, this basin was modified, and basins OS1, OS2, OS3, and OS4
have been added to the frontage on Trilby Ave. Basins OS5 and OS6 were added to represent
the frontage of South College Ave. The updated basins and delineations are shown in the
proposed drainage map in Appendix F of this report. A comprehensive table - SWMM Model
Comparison Table - shows the changes made to the basins as shown in Appendix B of this
Report.
The conveyance between Pond P366 and Pond P363 is both channelized and piped in events
greater than the 25 year and the channel will receive flow from the overflow weir. In events
under the 25 year the runoff will be piped.
Basin OS1, 0.73 acres and 82.0% impervious is composed of the intersection of Mars Drive and
West Trilby Road. Runoff from the intersection drains to an on-grade inlet, where it is piped and
treated in a water-quality pond P366. From then on, the runoff is piped and drains via the overflow
channel to the detention facility P363.
Basin OS2, 2.03 acres, 48.3% impervious, is composed of the northern portion of West Trilby
Road. The runoff from this basin drains into a roadside swale. The runoff drains to an inlet and is
piped and treated in a water-quality pond P366. From then on, the runoff is piped and drains into
a channel where it outfalls to the detention facility P363.
Basin OS3, 0.32 acres and 71.5% impervious, is composed of the south portion of West Trilby
Road and receives runoff. The runoff drains to a type D inlet from the CIP project and is piped
and treated in a water quality pond P366. From then on, the runoff goes into a channel and outlet
structure within a 30 “ RCP pipe where it outfalls to the detention facility P363.
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Basin OS4, 0.40 acres and 90.8% impervious this basin is composed of the south side of West
Trilby Road and includes the ROW improvements associated with the College and Trilby project.
The runoff from this basin drains into an on grade inlet built in Ridgewood Hills PUP First Filing.
Basin OS5, 1.69 acres and 76.3% impervious this basin drains undetained to an existing 10’ type
R inlet on the western portion of South College Ave directly adjacent to the pond outfall for
Pond P366. This inlet does not drain into the pond P363. The runoff from this basin drains to the
outfall pipe via the 10’ existing type R inlet.
Basin OS6, 0.88 acres and 78.3% impervious this basin drains undetained along the north western
portion of the site along South College Ave (east of the site) to a sump Inlet downstream of the
site adjacent to South College Ave and Skyway Drive.
Basin B770A, 0.36 acres, and 100.0% impervious, is composed of the southern portion of East
Trilby Road and the College and Trilby intersection. Runoff from this basin drains to an on-grade
type R inlet. Runoff is then piped to the water quality pond P366, and from there on the runoff
is routed in the overflow channel and outlet structure within a 30 “ RCP pipe to the detention
pond P363.
Basin B770B, 1.52 acres 89.0% impervious, composed of the eastern portion of South College
Ave South of Trilby road. Runoff from this basin drains to an on-grade type R inlet and is piped
to pond P363.
Basin B900A, 0.48 acres and 95.0% impervious, is composed of east Trilby Road. Runoff from this
basin drains to an on-grade type R-inlet; runoff is then piped to the water quality pond P366, and
from there on, the runoff is routed in the overflow channel and outlet structure within a 30”
RCP to the detention pond P363.
Basin B900B, 0.56 acres and 100.0% Impervious. This basin is composed of the eastern portion
of South College Ave north of the College and Trilby intersection. Runoff from this basin drains
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to an on-grade type R-Inlet. The runoff is piped to the water quality pond P366, and from there
on, the runoff is routed in the overflow channel and outlet structure with a 30” RCP to detention
pond P363.
Basin B910C, 1.30 acres and 90.0% impervious, this basin is composed of the northwestern
quadrant of the College and Trilby intersection. Runoff from this basin drains to an on-grade
type-R inlet. The runoff is piped to the water quality pond P366, and from there on the runoff is
routed in the overflow channel and outlet structure with a 30” RCP to detention pond P363.
Basin B920C, 1.71 acres and 66.0% impervious, is composed of commercial development, the
College and Trilby intersection, and is situated on the southwest quadrant of the College and
Trilby intersection. Runoff from this basin drains to an on-grade type R-Inlet; runoff is piped to
the water quality pond P366, and from there on, the runoff is routed in the overflow channel and
outlet structure with a 30” RCP to detention pond P363.
Basin B910D, 0.46 acres and 100.0% impervious. This basin is composed of the right in and right
for Ziggy's Coffee. Runoff from this basin drains to an on-grade type R inlet; runoff is then piped
to the water quality pond P366, and from there on, the runoff is routed in the overflow channel
and outlet structure with a 30” RCP to detention pond P363.
Basin B920A, 3.82 acres and 20.0% impervious. This basin is composed of the southern portion
of West Trilby Road. Runoff from this basin drains within a swale to a sump inlet; runoff is then
piped to the water quality P366, and from there on, the runoff is routed in the overflow channel
and outlet structure 30” RCP to detention pond P363.
Basin B920B, 0.99 acres and 63.0% impervious. This basin is composed of the southern portion
of West Trilby Rd. The runoff from this basin is conveyed within a swale to a sump inlet; runoff
is then piped to the water quality pond P366, and from there on, the runoff is routed in the
overflow channel and outlet structure with a 30” RCP to detention pond P363.
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Basin B910A, 2.99 acres and 74% impervious, is composed of Southgate Church and Ziggy's
Coffee. This basin drains to a detention pond situated near the northwest corner of the basin
and ultimately passes through pond P366 and Pond P363.
B830, 7.82 acres and 45% impervious; this basin is composed of Skyview South First Filing. The
runoff from this basin drains into a pan along side the eastern portion of the back of lots within
the subdivision. The runoff from this pan will overtop and go into an adjacent swale in the 100-
year event where the runoff will be detained in pond P363.
B840 11.79 acres and 45 % impervious; this basin is composed of Skyview South First Filing. The
runoff from this basin drains into a pan along site the eastern portion of the back of lots within
the subdivision. The runoff from this pan will overtop and go into an adjacent swale, where the
runoff will be detained in detention pond P363.
B930 4.71 acres and 31.2 % impervious; this basin is composed of the First Free Will Baptist
Church at 320 W Trilby Road. Runoff from this basin is detained in detention pond P930. Runoff
from this basin is released and ultimately is treated for water quality within pond P366 and is
detained within pond 363. This basin’s southern boundary was slightly modified to account for
the Frontage on W. Trilby Ave.
B876 16.97 acres and 60% impervious; this basin is made up of a social services organization
owned by Foothills Gateway Inc. that is composed of buildings and parking lots. This basin was
slightly modified to account for an inlet to accept runoff from basin B830 and B840, which drains
via a pan. The Stone Creek master plan specifies that B830 and B840 drain into pond P363. The
runoff from this basin drains to an existing swale on the western boundary of the College and
Trilby site and does not drain onto the College and Trilby Multi-Family site.
B850 17.24 acres and 10% impervious; this basin borders the northern boundary of the site and
is composed of Mars Collector Roadway and a self-storage facility. This basin’s southern boundary
was slightly modified to tie into the northern boundary of the College and Trilby Multi-Family
site.
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For additional information on offsite drainage basins and ponds in series, refer to the Wilson and
Company Stone Creek Proposed Conditions SWMM Schematic area of College and Trilby
Intersection Enhancements Storm System dated February of 2024 within Appendix E and the
Proposed SWMM map located in Appendix F.
PROJECT DESCRIPTION
PROJECT DESCRIPTION
College & Trilby is a residential multi-family development that will consist of a recreation center,
alleys, and local and collector roadways. The College & Trilby site will hold detention and water
quality improvements for the College and Trilby in continuity with the Stone Creek Master Plan.
PROPOSED DRAINAGE FACILITIES
GENERAL CONCEPT
The proposed improvements to the College and Trilby site will result in the developed condition
being treated for water quality and detained. Low-impact development best management
practices are proposed to improve the quality of runoff and aid in reducing peak flows. Specifically,
ADS isolator rows are proposed near the central portion of the site to treat and provide water
quality for the majority of the development. The remaining portion of the development will be
treated for water quality in the smaller water quality pond (P366) along with the tributary area
and which also treats runoff from the capital improvements to the Trilby and College intersection.
The majority of the runoff is treated for WQ/LID via ADS isolator row and extended detention
in P366. A small portion of the site’s impervious area is left untreated. Specifically, this impervious
area consists of residential lots facing Pond P363 and the channel in-between pond P363 and
P366, where runoff from water quality events will discharge across an extensive vegetated buffer.
This buffer provides significant infiltration and filtering, effectively reducing pollutants and
minimizing runoff before reaching Pond P366. No runoff from streets or alleys crosses this buffer,
resulting in fewer pollutants such as hydrocarbons typically associated with vehicular surfaces.
College & Trilby Multi-Family Community
Final Drainage Report
15
Given the reduced pollutant load and effective natural infiltration, this approach aligns with the
City of Fort Collins' intent and standards for stormwater quality management.
Runoff from the site is captured in inlets located in the alleys and on grade and sump inlets along
the curb and gutter. Runoff is conveyed in storm sewers, along the curb and gutter, and via surface
flow to the detention facility. Secondly, surface overflow paths will be provided such that the 100-
year storm flows remain at least one foot below the finished floor elevation at the time of the
final drainage report.
WATER QUALITY/ DETENTION FACILITIES
The majority of the water quality is treated within the onsite ADS isolator rows directly adjacent
to pond P363 and via Grass Buffers – that make up a small portion of the site’s treated impervious
area. The majority of the site is treated by LID methods via the ADS isolator row. The remaining
water quality within the site will be treated in tangent with water quality pond P366, which also
treats the College and Trilby Capital improvements.
The portion of the site that drains to the detention facility will drain over a grass buffer which
will provide water quality treatment when the runoff drains over and infiltrates the soil and
vegetation in a water quality event. The runoff that drains into the channel between pond 363
and 366 will act as a grass buffer, since the channel only receives overflow in events above the 25
year event.
While the grass buffers located within the overflow channel and adjacent to the detention pond
do not independently meet the City’s criteria for formal water quality or LID BMPs, they provide
supplemental treatment for the limited portion of impervious area that is not routed to dedicated
BMPs. This untreated impervious area is primarily composed of rooftop surfaces from
townhomes, which generate low pollutant loads and no vehicular runoff. As these areas discharge
to vegetated surfaces prior to entering the detention system, incidental infiltration and filtering
of runoff is expected to occur. Combined with the fact that over 90% of the site’s impervious
area is treated through engineered BMPs (e.g., ADS Isolator Rows and Pond P366), the design
College & Trilby Multi-Family Community
Final Drainage Report
16
exceeds the City’s minimum 75% LID treatment requirement and meets the overall intent of the
Stormwater Criteria Manual.
LOW IMPACT DEVELOPMENT
A minimum of 75 percent of the new impervious surface area is treated by a Low-Impact
Development (LID) best management practice (BMP) in accordance with City criteria. An
illustrative LID/ Surface Map is provided in Appendix G, and the sizing calculations of the LID
method is provided in Appendix D.
DRAINAGE DESIGN CRITERIA
REGULATIONS
This report was prepared to meet or exceed the City of Fort Collins stormwater criteria. The
City of Fort Collins Stormwater Criteria Manual (dated 2018)(FCSCM) and the Urban Drainage
Flood Control District’s (UDFCD) Drainage Criteria Manual (USDCM) Volumes 1, 2 and 3 were
referenced as guidelines for this design.
FOUR-STEP PROCESS TO PROTECT RECEIVING WATERS
The City of Fort Collins requires the Four Step Process to protect receiving waters. The four-
step process incorporates reducing runoff volume, treating water quality capture volume,
stabilizing streams, and implementing long-term source controls. Volume reduction is an
important part of the four-step process and is fundamental to effective stormwater management.
Per City criteria, a minimum of 75 percent of the new impervious surface area must be treated
by a Low-Impact Development (LID) best management practice (BMP). The site incorporates
underground ADS isolator rows, and a water quality pond designed to capture and treat at least
75% of the site’s water quality capture volume. The isolator rows need to be properly cleaned
and maintained to allow for long-term protection of the receiving waters. The proposed LID
BMPs will have the effect of slowing runoff through the site and increase infiltration and rainfall
interception by encouraging infiltration via the careful selection of vegetative cover. The dog park
will have a waste station, crusher fines and an underdrain system to provide infiltration so that in
a water quality event, a media of crusher fines with the underdrain system will effectively improve
water quality. The water quality for the dog park will ultimately be treated in the ADS isolator
College & Trilby Multi-Family Community
Final Drainage Report
17
rows. Some portions of the site do not drain directly to the ADS isolator rows or directly to the
water quality treatment pond. These portions of the site do not include roadways or alleys, and
there is a large degree of separation of land, generating a buffer to infiltrate and improve water
quality. These areas the P363 and the overflow channel between Pond P363 and P366 are
considered to be treated by a grass buffer bmp, the runoff is released out of Pond 363. The
improvements will decrease the runoff coefficient from the site and are expected to have no
adverse impact on the timing, quantity, or quality of stormwater runoff. The majority of the new
impervious area is treated by the proposed isolator rows in the mid-eastern portion of the site.
The remainder of the site is treated within water quality pond P366, as illustrated in the
LID/Surface Map provided in Appendix G.
Step 1 – Employ Runoff Reduction Practices
All of the developed runoff through the site will be routed through the onsite detention pond at pond
P363. The detention pond will restrict the flow rate of stormwater leaving the site and reduce the impact
on downstream drainage areas. Additionally, the design will allow for greater than 75% of the project’s
added impervious area to be routed through an approved LID water quality treatment train. The onsite
water quality BMPs includes a water quality pond, underground ADS StormTech isolator rows, and grass
buffers for water quality.
Step 2 – Implement BMPS that Provide a Water Quality Capture Volume
The site incorporates underground ADS isolator rows, and a water quality pond designed to capture and
treat at over 90% of the site’s water quality capture volume. The isolator rows need to be properly
cleaned and maintained to allow for long-term protection of the receiving waters. The proposed LID BMPs
will have the effect of slowing runoff through the site lot and increasing infiltration and rainfall interception
by encouraging infiltration and careful selection of vegetative cover.
Step 3 –Stabilize Drainageways
The stormwater improvements at College and Trilby improves the existing condition by eliminating flows
overtopping College Ave at Pond P363 and at Pond P366.
Step 4 – Implement site-specific and other source-control BMPs
The dog park will have a waste station, crusher fines, and an underdrain system to provide infiltration so
that in a water quality event, a media of crusher fines with the underdrain system will effectively improve
College & Trilby Multi-Family Community
Final Drainage Report
18
water quality before it is ultimately treated in the underground ADS StormTech isolator rows. An erosion
control plan and Stormwater Management Plan will be implemented to prevent erosion and control
sediment on the project site and downstream drainage ways during and after construction.
DEVELOPMENT CRITERIA REFERENCE AND CONSTRAINTS
The master drainage report for the Stone Creek Drainage Basin was prepared by ICON Engineering, Inc.
City of Fort Collins Stone Creek Basin Selected Plan of Improvements; Icon Engineering, Inc., October
2018. JR Engineering is following the general recommendations. The City of Fort Collins College and Trilby
intersection improvements plans are directly tributary to the site. The College and Trilby, intersection
improvement plan is being developed, and the Stone Creek basin master plan has been modified in a
memorandum from Wilson and Company dated 12/2023 that has been approved by the City of Fort
Collins.
Wilson and Company has designed the College and Trilby intersection improvements and provided an
updated corrected effective SWMM and proposed SWMM model for the site. JR Engineering is updating
and building off the Proposed SWMM model for the College and Trilby-Multi Family Development. JR
Engineering has incorporated the drainage improvement from College and Trilby into the site by
incorporating the site into the Wilson and Company’s design and the 2018 Stone Creek Master Plan (the
SC_100Yearprop SWMM model).
The Wilson and Company modeled pond P366 as a water quality pond with detention and improved
overtopping onto College Ave. JR Engineering is proposing that the smaller pond P366 be utilized as a
water quality pond with some detention, where an overflow channel will be built, and the majority of the
runoff will be detained in the larger pond - P363. The 30” RCP under College Avenue directly adjacent to
pond P363 will not be upsized to a 48” RCP per option B of the Stone Creek basin master plan. The
capacity of the existing 30” pipe is 60 cfs. Wilson and Company modeled the large pond with new LiDAR
topo and reduced the overtopping onto College Ave from the corrected effective condition to the
proposed condition. JR Engineering has eliminated overtopping onto College Ave.
The stormwater improvements at College and Trilby improve the existing condition by eliminating flows
overtopping College Ave at Pond P363 by adding additional volume to the detention pond. Overflow onto
College Avenue from Pond P366 is no longer present. Pond 366 will serve as a water quality pond with
additional attenuation provided up to the overflow weir (approximately 2ft). The overflow channel
College & Trilby Multi-Family Community
Final Drainage Report
19
between pond 366 and pond 363 element P366_OVERFLOW_CHANNEL, as shown within section CC
in the Drainage Map within Appendix F - receives flow overtopping from the weir in an event between
the 25-year and 50-year. The water quality Pond 366 was sized for onsite and offsite tributary area. To
develop a rating curve in SWMM, the volume used to calculate the WQCV in P366 was done in an MHFD
spreadsheet; the area in the spreadsheet override was multiplied by 1.2 to account for sediment
accumulation in accordance with the City of Fort Collins Criteria.
Table 1, as shown below, shows the 100-year volume and 100-year WSELV. Table 2 shows the maximum
release rate(s) for the detention for the facilities on site. Table 3 shows the approximate onsite pond drain
times modeled within SWMM.
Table 1: Pond Volumes
(Acre-Ft)WSELV RELEASE (CFS)
P363 9.78 5006.04 55.00
P366 1.41 5024.52 108.73
The water quality volume for P366 is 0.444 Acre-ft. – in a water quality event.
Table 2: 100 YR Release Rates
Rate (CFS)
Total overflow from pond P366
and runoff from channel basin.
unrestricted 30” outlet pipe.
48” RCP at 60 cfs capacity. Not
being upsized to 48” downstream.
Capacity is limited to a 30” pipe.
College & Trilby Multi-Family Community
Final Drainage Report
18
Table 3: Approx. Drain Times
P366 68 82
P363 67 85
CTL Thompson conducted groundwater monitoring for the site - the groundwater borings and
locations are shown in Appendix E of this report. The detention outfall elevation for Pond P363 will have
a dedicated outlet Structure. The proposed Storm-Tech isolator rows are situated approximately - 2’
above the high ground water elevation as shown in the ground water measurements from Aloterra in
Appendix E of this report. The water quality facility at Pond P366 is anticipated to be built before
construction starts on the College and Trilby Multi-Family Community is developed. Pond P366 will be
constructed by the City of Fort Collins for the College and Trilby Intersection improvements. Pond P366
will have its outlet structure replaced entirely to accommodate the College and Trilby development, and
the grading of the pond will be modified to have an access road from Stellar Drive.
HYDROLOGIC CRITERIA
Weighted percent imperviousness was calculated for each basin using the Fort Collins Stormwater
Criteria Manual Table 3.2-2 for each basin. EPA SWMM version 5.2 (Build 5.2.2) was used to model the
runoff for the site since the corresponding tributary area of the site is over 20 acres, and there are multiple
detention basins upstream of the site that are in series with one another. The City of Fort Collins area
has rainfall depths associated with the table below, as shown in Chapter 5 of the Fort Collins Stormwater
Criteria Manual. The corresponding site and tributary area were modeled in SWMM for the 2-year storm
and the 100-year storm and are shown in Table 4.1-4 below.
College & Trilby Multi-Family Community
Final Drainage Report
19
HYDRAULIC CRITERIA
StormCAD was utilized to determine the hydraulic capacity of the storm sewer system on site. Headloss
coefficients were input as recommended by AMEC. "Modeling Hydraulic and Energy Sewer Gradients in
Storm Sewers: A Comparison of Computational Methods." UDFCD, 6 Oct. 2009. The stormCAD V8i
input/results are shown in Appendix C.Additionally, hydraulic calculations for items such as street
capacity, inlet capacity, swales, channels, and the emergency spillway are provided within the Final Drainage
Report. The emergency spillway for pond P363 will not see flows overtopping College Avenue unless the
outlet structure is clogged in the 100 year event. Pond 363 has been graded to attenuate and detain runoff
and release into the 48" pipe, which is reduced downstream to a 30” pipe and has the capacity of a 30”
pipe.
College & Trilby Multi-Family Community
Final Drainage Report
20
FLOODPLAIN REGULATIONS COMPLIANCE
As previously stated, the site lies within FEMA Zone X, areas which are determined to be outside the
0.2% annual chance floodplain. The site is not located within a FEMA regulated floodplain, as shown in
Appendix A in the FEMA attachments. The site is also not located in the City of Fort Collins Floodplain,
as shown in Appendix A in the City of Fort Collins Flood map.
MODIFICATIONS OF CRITERIA
The site does not treat 100% of modified/ added impervious areas with traditional BMPs. 98.89% of
modified added onsite impervious area is treated for water quality. The small portion of runoff that is
untreated is from the overflow-swale on the western portion of the site composed of Basin OF1. This
basin is not directly tributary to any streets, alleys or roofs and will not negatively impact the water quality
of the site.
While the grass buffers located within the overflow channel and adjacent to the detention pond do not
independently meet the City’s criteria for formal water quality or LID BMPs, they provide supplemental
treatment for the limited portion of impervious area that is not routed to dedicated BMPs. This untreated
impervious area is primarily composed of rooftop surfaces from townhomes, which generate low pollutant
loads and no vehicular runoff. As these areas discharge to vegetated surfaces prior to entering the
detention system, incidental infiltration and filtering of runoff is expected to occur.
EROSION CONTROL
This Final Drainage Report has been prepared in accordance with applicable drainage, erosion control,
and stormwater management criteria and standards of the City of Fort Collins. The design and analysis
provided herein comply with local jurisdictional requirements and demonstrate adherence to the City of
Fort Collins Storm Drainage Criteria Manual. All erosion control measures and materials specified in the
Storm Water Management Plan and Grading, Erosion and Sediment control plan meet or exceed the City
of Fort Collins criteria.
CONCLUSIONS
COMPLIANCE WITH STANDARDS
The hydrologic and water quality calculations were performed using the required methods as outlined in
the City of Fort Collins Stormwater Criteria Manual. The proposed drainage improvements meet or
exceed the City’s requirements. This large detention pond (P363) is not held to the typical City of Fort
College & Trilby Multi-Family Community
Final Drainage Report
21
Collins detention release rates of the 2-year pre-developed event but the Stone Creek master plan release
rate of 60 cfs. This drainage report is in compliance with the detention requirement and recommendations
set forth within the Stone Creek drainage master plan. Pond P363 has been graded in and designed to
attenuate the runoff from the College and Trilby Multi-Family site. The large detention facility (P363) does
not exceed the existing maximum 60 cfs release rate, and there is an overflow channel with water quality
and additional attenuation provided within pond P366.
DRAINAGE CONCEPT
The proposed concept for the development of the Trilby College site involves surface flows and piping of
developed condition and offsite flow to the water quality pond, an onsite water quality facility with ADS
isolator rows, and the runoff for the site will be treated at detention facility P363 onsite. All the offsite
flows will be conveyed through the site and directly released at a rate under 60 cfs in compliance with the
Stone Creek Master plan. The existing conditions drainage patterns are maintained in the proposed. The
proposed improvements will have no adverse impacts on the flow rate, character, or quality of runoff
leaving the site. The proposed improvements will have no adverse impacts on adjacent properties.
College & Trilby Multi-Family Community
Final Drainage Report
22
REFERENCES
Fort Collins Stormwater Criteria Manual; City of Fort Collins, Colorado, December 2018.
Urban Storm Drainage Criteria Manual (Volumes 1, 2, and 3); Urban Drainage and Flood Control District,
June 2001.
City of Fort Collins Stone Creek Basin Selected Plan of Improvements; Icon Engineering, Inc., October
2018
Stone Creek SWMM Modeling for the College and Trilby Intersection Enhancements Project; Wilson and
Company, April 2022
College & Trilby Multi-Family Community
Final Drainage Report
APPENDIX A – FIGURES
A Westrian Company
Hydrologic Soil Group—Larimer County Area, Colorado
Natural Resources
Conservation Service
Web Soil Survey
National Cooperative Soil Survey
12/30/2020
Page 1 of 4
44
8
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493000 493100 493200 493300 493400 493500 493600
493000 493100 493200 493300 493400 493500 493600
40° 30' 9'' N
10
5
°
5
'
0
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W
40° 30' 9'' N
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5
°
4
'
3
0
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40° 29' 38'' N
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40° 29' 38'' N
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N
Map projection: Web Mercator Corner coordinates: WGS84 Edge tics: UTM Zone 13N WGS84
0 200 400 800 1200
Feet
0 50 100 200 300
Meters
Map Scale: 1:4,640 if printed on A portrait (8.5" x 11") sheet.
Soil Map may not be valid at this scale.
MAP LEGEND MAP INFORMATION
Area of Interest (AOI)
Area of Interest (AOI)
Soils
Soil Rating Polygons
A
A/D
B
B/D
C
C/D
D
Not rated or not available
Soil Rating Lines
A
A/D
B
B/D
C
C/D
D
Not rated or not available
Soil Rating Points
A
A/D
B
B/D
C
C/D
D
Not rated or not available
Water Features
Streams and Canals
Transportation
Rails
Interstate Highways
US Routes
Major Roads
Local Roads
Background
Aerial Photography
The soil surveys that comprise your AOI were mapped at
1:24,000.
Warning: Soil Map may not be valid at this scale.
Enlargement of maps beyond the scale of mapping can cause
misunderstanding of the detail of mapping and accuracy of soil
line placement. The maps do not show the small areas of
contrasting soils that could have been shown at a more detailed
scale.
Please rely on the bar scale on each map sheet for map
measurements.
Source of Map: Natural Resources Conservation Service
Web Soil Survey URL:
Coordinate System: Web Mercator (EPSG:3857)
Maps from the Web Soil Survey are based on the Web Mercator
projection, which preserves direction and shape but distorts
distance and area. A projection that preserves area, such as the
Albers equal-area conic projection, should be used if more
accurate calculations of distance or area are required.
This product is generated from the USDA-NRCS certified data as
of the version date(s) listed below.
Soil Survey Area: Larimer County Area, Colorado
Survey Area Data: Version 15, Jun 9, 2020
Soil map units are labeled (as space allows) for map scales
1:50,000 or larger.
Date(s) aerial images were photographed: Aug 11, 2018—Aug
12, 2018
The orthophoto or other base map on which the soil lines were
compiled and digitized probably differs from the background
imagery displayed on these maps. As a result, some minor
shifting of map unit boundaries may be evident.
Hydrologic Soil Group—Larimer County Area, Colorado
Natural Resources
Conservation Service
Web Soil Survey
National Cooperative Soil Survey
12/30/2020
Page 2 of 4
Hydrologic Soil Group
Map unit symbol Map unit name Rating Acres in AOI Percent of AOI
35 Fort Collins loam, 0 to 3
percent slopes
C 1.6 4.2%
36 Fort Collins loam, 3 to 5
percent slopes
C 0.7 1.7%
54 Kim loam, 3 to 5 percent
slopes
B 11.2 28.8%
56 Kim-Thedalund loams, 3
to 15 percent slopes
B 20.1 51.5%
63 Longmont clay, 0 to 3
percent slopes
D 4.1 10.6%
65 Midway clay loam, 5 to
25 percent slopes
D 1.2 3.0%
119 Wiley silt loam, 3 to 5
percent slopes
B 0.1 0.1%
Totals for Area of Interest 39.0 100.0%
Hydrologic Soil Group—Larimer County Area, Colorado
Natural Resources
Conservation Service
Web Soil Survey
National Cooperative Soil Survey
12/30/2020
Page 3 of 4
Description
Hydrologic soil groups are based on estimates of runoff potential. Soils are
assigned to one of four groups according to the rate of water infiltration when the
soils are not protected by vegetation, are thoroughly wet, and receive
precipitation from long-duration storms.
The soils in the United States are assigned to four groups (A, B, C, and D) and
three dual classes (A/D, B/D, and C/D). The groups are defined as follows:
Group A. Soils having a high infiltration rate (low runoff potential) when
thoroughly wet. These consist mainly of deep, well drained to excessively
drained sands or gravelly sands. These soils have a high rate of water
transmission.
Group B. Soils having a moderate infiltration rate when thoroughly wet. These
consist chiefly of moderately deep or deep, moderately well drained or well
drained soils that have moderately fine texture to moderately coarse texture.
These soils have a moderate rate of water transmission.
Group C. Soils having a slow infiltration rate when thoroughly wet. These consist
chiefly of soils having a layer that impedes the downward movement of water or
soils of moderately fine texture or fine texture. These soils have a slow rate of
water transmission.
Group D. Soils having a very slow infiltration rate (high runoff potential) when
thoroughly wet. These consist chiefly of clays that have a high shrink-swell
potential, soils that have a high water table, soils that have a claypan or clay
layer at or near the surface, and soils that are shallow over nearly impervious
material. These soils have a very slow rate of water transmission.
If a soil is assigned to a dual hydrologic group (A/D, B/D, or C/D), the first letter is
for drained areas and the second is for undrained areas. Only the soils that in
their natural condition are in group D are assigned to dual classes.
Rating Options
Aggregation Method: Dominant Condition
Component Percent Cutoff: None Specified
Tie-break Rule: Higher
Hydrologic Soil Group—Larimer County Area, Colorado
Natural Resources
Conservation Service
Web Soil Survey
National Cooperative Soil Survey
12/30/2020
Page 4 of 4
SITE
SITE
9,028
1,504.7
FCMaps
This map is a user generated static output from the City of Fort Collins FCMaps
Internet mapping site and is for reference only. Data layers that appear on this
map may or may not be accurate, current, or otherwise reliable.City of Fort Collins - GIS
1,143.0
1:
WGS_1984_Web_Mercator_Auxiliary_Sphere
Feet1,143.00571.50
Notes
Legend
6,859
SITE
College & Trilby Multi-Family Community
Final Drainage Report
APPENDIX B – HYDROLOGIC CALCULATIONS
Subdivision:College and Trilby Project Name:College and Trilby
Location:Fort Collins Project No.:
Calculated By:ARJ
Checked By:0
Date:12/5/24
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15
A1 1.90 100%0.15 7.8%40%0.00 0.0%90%0.14 6.4%2%1.62 1.7%16.0%
A2 1.79 100%0.48 27.0%40%0.00 0.0%90%0.48 24.0%2%0.83 0.9%51.9%
A3 1.62 100%0.42 26.1%40%0.09 2.1%90%0.15 8.4%2%1.05 1.3%38.0%
A4 0.42 100%0.25 58.4%40%0.00 0.0%90%0.00 0.0%2%0.18 0.8%59.3%
A5 0.75 100%0.36 47.9%40%0.00 0.0%90%0.17 20.5%2%0.22 0.6%69.0%
A6 0.47 100%0.35 72.9%40%0.00 0.0%90%0.00 0.0%2%0.13 0.5%73.5%
A7 1.26 100%0.45 35.7%40%0.00 0.0%90%0.40 28.6%2%0.41 0.7%65.0%
A8 0.30 100%0.20 64.9%40%0.00 0.0%90%0.00 0.0%2%0.11 0.7%65.6%
A9 0.18 100%0.11 65.0%40%0.00 0.0%90%0.00 0.0%2%0.06 0.7%65.7%
B1 0.63 100%0.28 43.7%40%0.00 0.0%90%0.23 32.1%2%0.13 0.4%76.3%
B2 1.17 100%0.06 5.1%40%0.00 0.0%90%0.00 0.0%2%1.11 1.9%7.0%
C1.1 3.82 100%1.16 30.3%40%0.00 0.0%90%0.55 13.1%2%2.11 1.1%44.5%
C1.2 0.72 100%0.16 22.9%40%0.00 0.0%90%0.11 13.9%2%0.44 1.2%38.1%
C1.3 0.18 100%0.07 38.8%40%0.00 0.0%90%0.05 26.7%2%0.06 0.6%66.2%
C2 1.12 100%0.45 40.4%40%0.00 0.0%90%0.00 0.0%2%0.67 1.2%41.6%
C3 2.22 100%0.88 39.7%40%0.00 0.0%90%0.74 29.9%2%0.60 0.5%70.2%
C4.1 0.82 100%0.47 57.1%40%0.00 0.0%90%0.09 9.7%2%0.26 0.6%67.5%
C4.2 1.76 100%0.51 29.2%40%0.00 0.0%90%0.43 21.9%2%0.81 0.9%52.1%
C5 1.34 100%0.86 64.3%40%0.00 0.0%90%0.00 0.0%2%0.48 0.7%65.0%
D1 0.29 100%0.22 75.6%40%0.00 0.0%90%0.00 0.0%2%0.07 0.5%76.1%
D2 0.50 100%0.26 53.0%40%0.00 0.0%90%0.08 13.9%2%0.16 0.6%67.5%
E1 0.42 100%0.20 47.0%40%0.00 0.0%90%0.16 34.1%2%0.06 0.3%81.3%
E2 0.73 100%0.57 77.7%40%0.00 0.0%90%0.00 0.0%2%0.16 0.4%78.1%
E3 0.23 100%0.18 77.6%40%0.00 0.0%90%0.00 0.0%2%0.05 0.4%78.1%
E4 0.17 100%0.08 46.6%40%0.00 0.0%90%0.03 15.2%2%0.06 0.7%62.6%
E5 0.38 100%0.11 28.0%40%0.00 0.0%90%0.03 8.1%2%0.24 1.3%37.4%
E6 0.86 100%0.04 4.4%40%0.00 0.0%90%0.00 0.0%2%0.82 1.9%6.3%
OF1 0.53 100%0.06 10.4%40%0.00 0.0%90%0.00 0.0%2%0.47 1.8%12.2%
F1 1.20 100%0.07 6.0%40%0.00 0.0%90%0.32 24.3%2%0.81 1.3%31.7%
G1 1.49 100%0.73 49.1%40%0.00 0.0%90%0.41 24.5%2%0.35 0.5%74.0%
G2 0.62 100%0.29 46.3%40%0.00 0.0%90%0.25 36.5%2%0.08 0.3%83.1%
G3 1.06 100%0.16 15.5%40%0.00 0.0%90%0.48 40.5%2%0.42 0.8%56.8%
G4 0.82 100%0.50 60.6%40%0.00 0.0%90%0.14 15.5%2%0.18 0.4%76.6%
H1 5.81 100%0.20 3.5%40%0.00 0.0%90%0.12 1.9%2%5.48 1.9%7.3%
TOTAL 39.59 42.4%
OS1 0.74 100%0.60 81.6%40%0.00 0.0%90%0.00 0.0%2%0.14 0.4%82.0%
OS2 2.03 100%0.66 32.3%40%0.00 0.0%90%0.33 14.7%2%1.38 1.4%48.3%
OS3 0.32 100%0.23 70.9%40%0.00 0.0%90%0.00 0.0%2%0.09 0.6%71.5%
OS4 0.40 100%0.36 90.6%40%0.00 0.0%90%0.00 0.0%2%0.04 0.2%90.8%
OS5 1.69 100%1.28 75.8%40%0.00 0.0%90%0.00 0.0%2%0.41 0.5%76.3%
OS6 0.88 100%0.63 71.7%40%0.00 0.0%90%0.00 0.0%2%0.25 0.6%72.2%
B920A 4.36 20.0%
B830 7.82 45.0%
B840 11.79 45.0%
B850 17.24 10.0%
B930 4.71 100%1.02 21.7%40%0.00 0.0%90%0.42 8.0%2%3.69 1.6%31.2%
B910A 2.99 74.0%
B910C 1.30 90.0%
B910D 0.46 90.0%
COMPOSITE % IMPERVIOUS CALCULATIONS
% Imp. Area (ac)% Imp.Area (ac)Weighted
% Imp.
39823.00
Weighted
% Imp.
Basins Total
Weighted %
Imp.Basin ID Total Area (ac) % Imp. Area (ac)% Imp. Area (ac)Weighted
% Imp.
Weighted
% Imp.
X:\3970000.all\3979303\Excel\Drainage\3979303 Drainage_Calcs_Template_v2.07.xlsm Page 1 of 1 12/5/2024
Subdivision:College and Trilby Project Name:College and Trilby
Location:Fort Collins Project No.:
Calculated By:ARJ
Checked By:0
Date:12/5/24
1.0 2.0 3.0 4.0 5.0 6.0 7.0 8.0 9.0 10.0 11.0 12.0 13.0 14.0 15.0 16.0 17.0 18.0 19.0 20.0 21.0
Hydrologic
Soils Group
A1 1.90 B 0.95 0.15 0.07 0.09 0.95 0.14 0.07 0.08 0.50 0.00 0.00 0.00 0.15 1.62 0.13 0.16 0.27 0.34
A2 1.79 B/D 0.95 0.48 0.26 0.32 0.95 0.48 0.25 0.32 0.50 0.00 0.00 0.00 0.20 0.83 0.09 0.12 0.60 0.75
A3 1.62 B 0.95 0.42 0.25 0.31 0.95 0.15 0.09 0.11 0.50 0.09 0.03 0.03 0.25 1.05 0.16 0.20 0.50 0.62
A4 0.42 B 0.95 0.25 0.56 0.69 0.95 0.00 0.00 0.00 0.50 0.00 0.00 0.00 0.20 0.18 0.08 0.10 0.64 0.80
A5 0.75 B/D 0.95 0.36 0.46 0.57 0.95 0.17 0.22 0.27 0.50 0.00 0.00 0.00 0.20 0.22 0.06 0.07 0.73 0.91
A6 0.47 D 0.95 0.35 0.69 0.87 0.95 0.00 0.00 0.00 0.50 0.00 0.00 0.00 0.25 0.13 0.07 0.08 0.76 0.95
A7 1.26 B 0.95 0.45 0.34 0.42 0.95 0.40 0.30 0.38 0.50 0.00 0.00 0.00 0.25 0.41 0.08 0.10 0.72 0.90
A8 0.30 A 0.95 0.20 0.62 0.77 0.95 0.00 0.00 0.00 0.50 0.00 0.00 0.00 0.20 0.11 0.07 0.09 0.69 0.86
A9 0.18 A 0.95 0.11 0.62 0.77 0.95 0.00 0.00 0.00 0.50 0.00 0.00 0.00 0.20 0.06 0.07 0.09 0.69 0.86
B1 0.63 D 0.95 0.28 0.42 0.52 0.95 0.23 0.34 0.42 0.50 0.00 0.00 0.00 0.20 0.13 0.04 0.05 0.80 0.99
B2 1.17 D 0.95 0.06 0.05 0.06 0.95 0.00 0.00 0.00 0.50 0.00 0.00 0.00 0.25 1.11 0.24 0.30 0.29 0.36
D1 0.29 D 0.95 0.22 0.72 0.90 0.95 0.00 0.00 0.00 0.50 0.00 0.00 0.00 0.20 0.07 0.05 0.06 0.77 0.96
D2 0.50 D 0.95 0.26 0.50 0.63 0.95 0.08 0.15 0.18 0.50 0.00 0.00 0.00 0.20 0.16 0.06 0.08 0.71 0.89
C1.1 3.82 B 0.95 1.16 0.29 0.36 0.95 0.55 0.14 0.17 0.50 0.00 0.00 0.00 0.25 2.11 0.14 0.17 0.56 0.70
C1.2 0.72 B/C 0.95 0.16 0.22 0.27 0.95 0.11 0.15 0.18 0.50 0.00 0.00 0.00 0.20 0.44 0.12 0.15 0.49 0.61
C1.3 0.18 B/C 0.95 0.07 0.37 0.46 0.95 0.05 0.28 0.35 0.50 0.00 0.00 0.00 0.20 0.06 0.06 0.08 0.71 0.89
C2 1.12 B 0.95 0.45 0.38 0.48 0.95 0.00 0.00 0.00 0.50 0.00 0.00 0.00 0.20 0.67 0.12 0.15 0.50 0.63
C3 2.22 B 0.95 0.88 0.38 0.47 0.95 0.74 0.32 0.39 0.50 0.00 0.00 0.00 0.25 0.60 0.07 0.08 0.76 0.95
C4.1 0.82 B 0.95 0.47 0.54 0.68 0.95 0.09 0.10 0.13 0.50 0.00 0.00 0.00 0.20 0.26 0.06 0.08 0.71 0.89
C4.2 1.76 B 1.95 0.51 0.57 0.71 1.95 0.43 0.48 0.59 1.50 0.00 0.00 0.00 1.20 0.81 0.56 0.70 1.00 1.00
C5 1.34 B 0.95 0.86 0.61 0.76 0.95 0.00 0.00 0.00 0.50 0.00 0.00 0.00 0.20 0.48 0.07 0.09 0.68 0.85
E1 0.42 B/D 0.95 0.20 0.45 0.56 0.95 0.16 0.36 0.45 0.50 0.00 0.00 0.00 0.20 0.06 0.03 0.04 0.84 1.00
E2 0.73 B 0.95 0.57 0.74 0.92 0.95 0.00 0.00 0.00 0.50 0.00 0.00 0.00 0.15 0.16 0.03 0.04 0.77 0.96
E3 0.23 B 0.95 0.18 0.74 0.92 0.95 0.00 0.00 0.00 0.50 0.00 0.00 0.00 0.15 0.05 0.03 0.04 0.77 0.96
E4 0.17 B/D 0.95 0.08 0.44 0.55 0.95 0.03 0.16 0.20 0.50 0.00 0.00 0.00 0.20 0.06 0.07 0.09 0.68 0.85
E5 0.38 D 0.95 0.11 0.27 0.33 0.95 0.03 0.09 0.11 0.50 0.00 0.00 0.00 0.25 0.24 0.16 0.20 0.51 0.64
E6 0.86 B/D 0.95 0.04 0.04 0.05 0.95 0.00 0.00 0.00 0.50 0.00 0.00 0.00 0.25 0.82 0.24 0.30 0.28 0.35
F1 1.20 B/D 0.95 0.07 0.06 0.07 0.95 0.32 0.26 0.32 0.50 0.00 0.00 0.00 0.20 0.81 0.13 0.17 0.45 0.56
G1 1.49 B 0.95 0.73 0.47 0.58 0.95 0.41 0.26 0.32 0.50 0.00 0.00 0.00 0.15 0.35 0.04 0.04 0.76 0.95
G2 0.62 B 0.95 0.29 0.44 0.55 0.95 0.25 0.39 0.48 0.50 0.00 0.00 0.00 0.15 0.08 0.02 0.02 0.84 1.00
G3 1.06 B 0.95 0.16 0.15 0.18 0.95 0.48 0.43 0.53 0.50 0.00 0.00 0.00 0.15 0.42 0.06 0.07 0.63 0.79
G4 0.82 B 0.95 0.50 0.58 0.72 0.95 0.14 0.16 0.20 0.50 0.00 0.00 0.00 0.15 0.18 0.03 0.04 0.77 0.97
H1 5.81 B 0.95 0.20 0.03 0.04 0.95 0.12 0.02 0.03 0.50 0.00 0.00 0.00 0.20 5.48 0.19 0.24 0.24 0.30
OF1 0.53 B 0.95 0.06 0.10 0.12 0.95 0.00 0.00 0.00 0.50 0.00 0.00 0.00 0.20 0.47 0.18 0.22 0.28 0.35
COMP.37.06 0.56 0.69
39823.00
Total Area
(ac)Runoff
Coefficient
COMPOSITE RUNOFF COEFFICIENT CALCULATIONS
Basin ID Area (ac) 2 - YEAR C 100 - YEAR C Runoff
Coefficient Area (ac)2 - YEAR C 100 - YEAR C
Gravel
Runoff
Coefficient Area (ac)2 - YEAR C
Basins Total Weighted 100
YEAR CRunoff
Coefficient Area (ac)2 - YEAR C 100 - YEAR C
Paved Roads/Ashphalt/Concrete Roofs Lawns
Basins Total Weighted 2
YEAR C100 - YEAR C
X:\3970000.all\3979303\Excel\Drainage\3979303 Drainage_Calcs_Template_v2.07.xlsm Page 1 of 1 12/5/2024
Subdivision:College and Trilby Project Name:College and Trilby
Location:Fort Collins Project No.:
Calculated By:ARJ
Checked By:0
Date:12/5/24
1.0 2.0 3.0 4.0 5.0 6.0 7.0 8.0 9.0 10.0 11.0 12.0 13.0 14.0 15.0 16.0 17.0 18.0 19.0 20.0 21.0
BASIN D.A. Hydrologic Impervious C2 C100 L S o t i - 2Year t i - 100 Year L t S t K VEL.t t COMP.t c-2 Year COMP.t c 100 - Year TOTAL Urbanized t c t c-2 Year t c-100 Year
ID (ac)Soils Group (%)(ft)(%)(min)(min)(ft)(%)(ft/s)(min)(min)(min)LENGTH (ft)(min)(min)(min)
A1 1.90 B 16%0.27 0.34 200 2.0%79.8 73.4 403 2.0%15.0 2.1 3.2 83.0 76.6 603.0 13.4 13.4 13.4
A2 1.79 B/D 52%0.60 0.75 40 2.0%21.4 14.9 424 1.1%20.0 2.1 3.4 24.8 18.3 464.0 12.6 12.6 12.6
A3 1.62 B 38%0.50 0.62 41.5 2.0%26.4 20.9 420 2.3%20.0 3.0 2.3 28.7 23.2 461.5 12.6 12.6 12.6
A4 0.42 B 59%0.64 0.80 32.5 2.0%17.9 11.7 404 2.8%20.0 3.3 2.0 19.9 13.7 436.5 12.4 12.4 12.4
A5 0.75 B/D 69%0.73 0.91 13 2.0%9.1 4.6 374 1.7%20.0 2.6 2.4 11.4 6.9 387.4 12.2 11.4 6.9
A6 0.47 D 73%0.76 0.95 13 2.0%8.3 3.7 354 1.9%20.0 2.7 2.2 10.5 5.8 367.0 12.0 10.5 5.8
A7 1.26 B 65%0.72 0.90 32 2.0%14.5 7.6 393 1.9%20.0 2.8 2.4 16.9 9.9 425.2 12.4 12.4 9.9
A8 0.30 A 66%0.69 0.86 32 2.0%15.9 9.3 183 2.2%20.0 3.0 1.0 16.9 10.3 215.0 11.2 11.2 10.3
A9 0.18 A 66%0.69 0.86 32 2.0%15.9 9.3 110 1.3%20.0 2.3 0.8 16.7 10.1 141.8 10.8 10.8 10.1
B1 0.63 D 76%0.80 0.99 21 8.0%6.0 2.1 189 2.8%20.0 3.4 0.9 6.9 3.0 210.0 11.2 6.9 5.0
B2 1.17 D 7%0.29 0.36 35 25.0%14.2 13.0 364 1.2%20.0 2.2 2.7 17.0 15.7 399.0 12.2 12.2 12.2
D1 0.29 D 76%0.77 0.96 13 2.0%8.2 3.5 243 2.4%20.0 3.1 1.3 9.5 4.8 256.0 11.4 9.5 5.0
D2 0.50 D 68%0.71 0.89 13 2.0%9.5 5.1 251 2.5%20.0 3.2 1.3 10.8 6.4 264.0 11.5 10.8 6.4
C1.1 3.82 B 44%0.56 0.70 32 2.0%20.6 15.2 1018 1.0%20.0 2.0 8.5 29.1 23.7 1050.0 15.8 15.8 15.8
C1.2 0.72 B/C 38%0.49 0.61 44 2.0%27.6 22.1 82 3.2%20.0 3.6 0.4 28.0 22.5 125.6 10.7 10.7 10.7
C1.3 0.18 B/C 66%0.71 0.89 46 2.0%17.8 9.6 53 3.0%20.0 3.5 0.3 18.1 9.8 99.0 10.6 10.6 9.8
C2 1.12 B 42%0.50 0.63 32 2.0%23.0 18.1 977 1.1%20.0 2.1 7.7 30.6 25.8 1008.7 15.6 15.6 15.6
C3 2.22 B 70%0.76 0.95 8 2.0%6.5 2.9 866 0.9%20.0 1.9 7.8 14.3 10.6 874.5 14.9 14.3 10.6
C4.1 0.82 B 67%0.71 0.89 13 2.0%9.6 5.2 360 1.9%20.0 2.8 2.2 11.8 7.4 373.0 12.1 11.8 7.4
C4.2 1.76 B 52%1.00 1.00 13 2.0%2.5 2.5 237 1.6%20.0 2.5 1.6 4.0 4.0 250.0 11.4 5.0 5.0
C5 1.34 B 65%0.68 0.85 13 2.0%10.2 6.1 745 1.4%20.0 2.4 5.2 15.5 11.3 758.1 14.2 14.2 11.3
E1 0.42 B/D 81%0.84 1.00 55 3.0%11.6 4.4 208 1.5%20.0 2.5 1.4 13.0 5.8 263.0 11.5 11.5 5.8
E2 0.73 B 78%0.77 0.96 13 2.0%8.1 3.3 313 1.8%20.0 2.7 1.9 10.0 5.3 326.0 11.8 10.0 5.3
E3 0.23 B 78%0.77 0.96 41 2.0%14.3 5.9 88 0.6%20.0 1.5 0.9 15.3 6.9 129.2 10.7 10.7 6.9
E4 0.17 B/D 63%0.68 0.85 10 2.0%9.1 5.5 64 6.3%20.0 5.0 0.2 9.3 5.7 74.0 10.4 9.3 5.7
E5 0.38 D 37%0.51 0.64 5 25.0%3.9 3.1 194 2.1%20.0 2.9 1.1 5.0 4.2 199.0 11.1 5.0 5.0
E6 0.86 B/D 6%0.28 0.35 34 25.0%14.1 12.9 114 2.0%20.0 2.8 0.7 14.8 13.6 148.0 10.8 10.8 10.8
F1 1.20 B/D 32%0.45 0.56 30 25.0%10.6 8.7 411 2.6%20.0 3.2 2.1 12.7 10.9 441.0 12.5 12.5 10.9
G1 1.49 B 74%0.76 0.95 20 3.0%9.0 4.0 573 1.7%20.0 2.6 3.7 12.7 7.7 593.0 13.3 12.7 7.7
G2 0.62 B 83%0.84 1.00 20 3.0%6.8 2.7 336 2.8%20.0 3.4 1.7 8.5 4.3 356.3 12.0 8.5 5.0
G3 1.06 B 57%0.63 0.79 50 1.5%24.6 16.2 295 2.7%20.0 3.3 1.5 26.1 17.7 345.0 11.9 11.9 11.9
G4 0.82 B 77%0.77 0.97 21 3.0%8.9 3.7 428 2.2%20.0 2.9 2.4 11.3 6.1 449.4 12.5 11.3 6.1
H1 5.81 B 7%0.24 0.30 115 25.0%27.2 25.3 434 0.5%20.0 1.4 5.1 32.3 30.4 549.0 13.1 13.1 13.1
OF1 0.53 B 12%0.28 0.35 5 2.0%12.5 11.4 435 0.5%20.0 1.4 5.1 17.6 16.6 440.0 12.4 12.4 12.4
NOTES:
STANDARD FORM SF-2
TIME OF CONCENTRATION
SUB-BASIN Time of Concentration -Check
39823.00
FINAL(Tc)DATA
INITIAL/OVERLAND
(Ti)
TRAVEL TIME
(Tt)
X:\3970000.all\3979303\Excel\Drainage\3979303 Drainage_Calcs_Template_v2.07.xlsm Page 1 of 1 12/5/2024
Project Name:College and Trilby
Subdivision:College and Trilby Project No.:
Location:Fort Collins Calculated By:ARJ
Design Storm:Checked By:0
Date:
TRAVEL TIME
STREET
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REMARKS
Runoff into chase goes onto Street
1a A1 1.90 0.27 13.4 0.51 1.96 1.0
Runoff from Alley goes to on-grade inlet
2a A2 1.79 0.60 12.6 1.08 2.01 2.2 0.0 0.00 3 80 3.5 0.4
Runoff Captured by On-grade inlet
2ai 12.6 1.08 2.01 2.2
On-grade inlet
3a A3 1.62 0.50 12.6 0.81 2.01 1.6 13.4 1.32 1.96 2.6 0.0 0.01 1.7 477 2.6 3.0 Tributary Runoff from from Basins A4 and A1 and bypass flow from basin 2a
Runoff Captured by On-grade inlet
3ai 13.4 1.31 1.96 2.6
Piped runoff
1.2 15.6 2.39 1.83 4.4 4.4 2.4 1.0 18 22 5.6 0.1 Tributary basins A4 and A1
Captured by on grade inlet
4a A4 0.42 0.64 12.4 0.27 2.02 0.5 12.4 0.27 2.02 0.5 0.0 0.00 2 430 2.8 2.5 Tributary Basin A5. Bypass to DP 8a
Runoff Captured by On-grade inlet
4ai 12.4 0.27 2.02 0.5
Piped runoff
1.3 15.7 2.66 1.83 4.9 4.9 2.7 2.0 18 51 7.5 0.1 Tributary basins A2,A3 and A4
Captured by on grade inlet
5a A5 0.75 0.73 11.4 0.55 2.10 1.2 0.0 0.00 1.7 472 2.6 3.0 Tributary Basin A6
5ai 11.4 0.55 2.10 1.2
Captured by on grade inlet
6a A6 0.47 0.76 10.5 0.36 2.17 0.8 0.0 0.00 2.9 300 3.4 1.5 Tributary Basin A7. Bypass to DP d2
Runoff Captured by On-grade inlet
6ai 10.5 0.36 2.17 0.8
Piped runoff from basins A5 and A6
1.1 11.4 0.91 2.10 1.9 1.9 0.9 1.0 18 52 2.0 0.4
Piped runoff basin A1-A6
1.4 15.6 3.57 1.83 6.5 6.5 3.6 1.0 24 244 6.2 0.7
Captured by on grade inlet Basin A8
8a A8 0.30 0.69 11.2 0.21 2.11 0.4 0.0 0.01 1.7 334 2.6 2.1 by-pass to DP 2d
8ai 11.2 0.20 2.11 0.4
Piped runoff basin A1-A7 and Basin A8
1.5 16.3 3.77 1.79 6.8 6.8 3.8 0.5 24 193 4.9 0.7
Bypass Flow to dp 4c
7a A7 1.26 0.72 12.4 0.91 2.02 1.8 15.6 0.92 1.83 1.7 0.0 0.00 0.6 305 1.5 3.3
Runoff captured in inlet
7ai 15.6 0.92 1.83 1.7
Bypass Flow to dp 5c
9a A9 0.18 0.69 10.8 0.12 2.15 0.3 0.0 0.00 0.6 305 1.5 3.3
Runoff Captured in Inlet
9ai 10.8 0.12 2.15 0.3
Piped runoff basin A1-A10
1.6 16.9 4.81 1.75 8.4 8.4 4.8 0.5 36 250 5.0 0.8
DIRECT RUNOFF TOTAL RUNOFF STREET PIPE
STANDARD FORM SF-3
STORM DRAINAGE SYSTEM DESIGN
(RATIONAL METHOD PROCEDURE)
X:\3970000.all\3979303\Excel\Drainage\3979303 Drainage_Calcs_Template_v2.07.xlsm Page 1 of 3 12/9/2024
Project Name:College and Trilby
Subdivision:College and Trilby Project No.:
Location:Fort Collins Calculated By:ARJ
Design Storm:Checked By:0
Date:
TRAVEL TIME
STREET
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t
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tt
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REMARKS
DIRECT RUNOFF TOTAL RUNOFF STREET PIPE
STANDARD FORM SF-3
STORM DRAINAGE SYSTEM DESIGN
(RATIONAL METHOD PROCEDURE)
1.2c C1.2 0.72 0.49 10.7 0.35 2.15 0.8 0.0 0.00 5 108 4.5 0.4
1.2ci 10.7 0.35 2.15 0.8
1.3c C1.3 0.18 0.71 10.6 0.13 2.17 0.3 0.0 0.00 5 80 4.5 0.3 By Passflow to inlet 4c
1.3ci 10.6 0.13 2.17 0.3
Runoff from basin C1.1 onto on grade inlet
1.1c C1.1 3.82 0.56 15.8 2.15 1.82 3.9 15.8 2.15 1.82 3.9 0.6 0.31 1.7 330 2.6 2.1
Runoff Captured by inlet
1.1ci 15.8 1.84 1.82 3.4
Piped Runoff
2.0 10.7 0.48 2.15 1.0 1.0 2.2 0.5 18 60 2.9 0.3 Tributary Basin C1.2 and C1.3
Piped Runoff
2.1 15.8 2.32 1.82 4.2 Tributary Basin C1.2 and C1.3 and Basin C1.1
On grade runoff from basin C2
2c C2 1.12 0.50 15.6 0.56 1.83 1.0 0.2 0.08 1.8 345 2.7 2.1
2ci 15.6 0.48 1.83 0.9 ByPass to DP 4C
Piped runoff
2.2 15.8 2.80 1.82 5.1 5.1 2.8 1.0 18 290 5.9 0.8 Basin C1.1 -C1.3 and Basin C2
3c C3 2.22 0.76 14.3 1.69 1.91 3.2 0.0 0.00 1.8 125 2.7 0.8 Bypass to DP 4c
3ci 14.3 1.69 1.91 3.2
Piped runoff basins C1.1-C1.3, C2 and C3
2.3 15.8 4.49 1.82 8.2 8.2 4.5 1.0 24 100 6.6 0.3
4.1c C4.1 0.82 0.71 11.8 0.58 2.07 1.2 17.9 0.97 1.70 1.7 0.0 0.00 1.2 300 2.2 2.3
4.1ci 17.9 0.97 1.70 1.7
Piped runoff basins C1.1-C1.3, C2, C3, C4.1
2.4 17.9 5.46 1.70 9.3
Sump Inlet - bypass flows from 4.1c and 8a
4.2c C4.2 1.76 1.00 5.0 1.76 2.85 5.0 20.2 1.76 1.60 2.8
Piped runoff Basins A1-A10 and basin C1.1-C1.3, C2, C3 and C4.1
2.5 20.2 12.03 1.60 19.2
Sump Inlet -by pass flow from 10a
5c C5 1.34 0.68 14.2 0.92 1.91 1.8 14.2 0.92 1.91 1.8
Piped runoff Basins A1-A10 and basin C1.1-C1.3, C2, C3 and C4
2.6 20.2 12.95 1.60 20.7 20.7 12.9 1.5 42 80 9.5 0.1 and Basin C5
Runoff Captured by on grade Alley inlet
1g G1 1.49 0.76 12.7 1.14 2.00 2.3 0.0 0.00 1.5 171 2.4 1.2 Tributary Basin G1
1gi 12.7 1.14 2.00 2.3
Piped Runoff
2.7 20.4 14.09 1.59 22.4 22.4 14.1 2.0 48 150 10.6 0.2 Tributary Basins A1-10 Basin C1.1-C1.3, C4, C5 and G1
Runoff from Alley
2g G2 0.62 0.84 8.5 0.53 2.35 1.2
X:\3970000.all\3979303\Excel\Drainage\3979303 Drainage_Calcs_Template_v2.07.xlsm Page 2 of 3 12/9/2024
Project Name:College and Trilby
Subdivision:College and Trilby Project No.:
Location:Fort Collins Calculated By:ARJ
Design Storm:Checked By:0
Date:
TRAVEL TIME
STREET
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C*
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REMARKS
DIRECT RUNOFF TOTAL RUNOFF STREET PIPE
STANDARD FORM SF-3
STORM DRAINAGE SYSTEM DESIGN
(RATIONAL METHOD PROCEDURE)
Runoff Captured by a series of inlets
3g G3 1.06 0.63 11.9 0.67 2.06 1.4
Runoff to inlet in alley at Dp 4g - sump
4g G4 0.82 0.77 11.3 0.63 2.10 1.3 13.9 1.16 1.93 2.2
Piped Runoff
3.1 13.9 1.79 1.93 3.5 3.5 1.8 1.0 36 150 4.9 0.5 Tributary basins G2-G4
3.2 20.6 15.88 1.58 25.1 Outfall into Forebay
Runoff from Alley Drains into Chase
1e E1 0.42 0.84 11.5 0.35 2.09 0.7
Runoff from Cu-de-Sac and Runoff from chase
2e E2 0.73 0.77 10.0 0.56 2.21 1.2 13.3 0.91 1.96 1.8 1.8 0.9 1.0 24 30 4.3 0.1 Tributary Runoff basin E1 and E2
Runoff from sump inlet
3e E3 0.23 0.77 10.7 0.18 2.15 0.4 0.4 0.2 1.0 12 65 2.8 0.1
Tributary runoff from basin E1-E3
4.1 11.5 1.68 2.09 3.5 3.5 1.7 1.0 18 39 5.3 0.1
J910B OFFSITE Runoff from Trilby Road - picked up by 15 ft PR and 10 ft type r inlets
5.1 14.88 Runoff entered in from SWMM MODEL from J910B
1b B1 0.63 0.80 6.9 0.50 2.53 1.3
Offsite Runoff
5.2 16.1 Offsite runoff + basin B1
2b B2 1.17 0.29 12.2 0.33 2.03 0.7
5.3 16.8 Offsite runoff + basin B1 and B2
L367_Orifice
P367 Outfall 0.12 Runoff entered in from SWMM MODEL
Sump inlet, Recives by pass flow from basin A7
2d D2 0.50 0.71 10.8 0.35 2.15 0.8 12.0 0.35 2.05 0.7
Offsite runoff from pond P367, Offsite runoff from Trilby Road
6.1 17.7 Onsite basins B1 and B2 and D2
1d D1 0.29 0.77 9.5 0.22 2.26 0.5
Offsite runoff from pond P367, Offsite runoff from Trilby Road
6.2 18.2 Onsite basins B1 and B2 and D2 and D1
Notes:
Street and Pipe C*A values are determined by Q/i using the catchment's intensity value.
X:\3970000.all\3979303\Excel\Drainage\3979303 Drainage_Calcs_Template_v2.07.xlsm Page 3 of 3 12/9/2024
Project Name:College and Trilby
Subdivision:College and Trilby Project No.:
Location:Fort Collins Calculated By:ARJ
Design Storm:Checked By:0
Date:
TRAVEL TIME
STREET
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REMARKS
Runoff into chase goes onto Street
1a A1 1.90 0.34 13.4 0.64 6.85 4.4
Runoff from Alley goes to on-grade inlet
2a A2 1.79 0.75 12.6 1.35 7.02 9.5 6.5 0.93 3 80 3.5 0.4
Runoff Captured by On-grade inlet
2ai 12.6 0.42 7.02 3.0
On-grade inlet
3a A3 1.62 0.62 12.6 1.01 7.02 7.1 13.4 2.58 6.85 17.6 5.5 0.81 1.7 477 2.6 3.0 Tributary Runoff from from Basins A4 and A1 and bypass flow from basin 2a
Runoff Captured by On-grade inlet
3ai 13.4 1.77 6.85 12.1
Piped runoff
1.2 15.6 2.19 6.39 14.0 14.0 2.2 1.0 18 22 7.9 0.0 Tributary basins A4 and A1
Captured by on grade inlet
4a A4 0.42 0.80 12.4 0.34 7.06 2.4 12.4 0.34 7.06 2.4 0.4 0.05 2 430 2.8 2.5 Tributary Basin A5. Bypass to DP 8a
Runoff Captured by On-grade inlet
4ai 12.4 0.29 7.06 2.0
Piped runoff
1.3 15.7 2.48 6.38 15.8 15.8 2.5 2.0 18 51 9.5 0.1 Tributary basins A2,A3 and A4
Captured by on grade inlet
5a A5 0.75 0.91 6.9 0.69 8.83 6.1 1.5 0.17 1.7 472 2.6 3.0 Tributary Basin A6
5ai 6.9 0.52 8.83 4.6
Captured by on grade inlet
6a A6 0.47 0.95 5.8 0.45 9.42 4.2 0.6 0.07 2.9 300 3.4 1.5 Tributary Basin A7. Bypass to DP d2
Runoff Captured by On-grade inlet
6ai 5.8 0.38 9.42 3.6
Piped runoff from basins A5 and A6
1.1 6.9 0.90 8.83 8.0 8.0 0.9 1.0 18 52 2.0 0.4
Piped runoff basin A1-A6
1.4 15.6 3.39 6.39 21.6 21.6 3.4 1.0 24 244 8.2 0.5
STORM DRAINAGE SYSTEM DESIGN
STANDARD FORM SF-3
(RATIONAL METHOD PROCEDURE)
PIPE
100-Year
DIRECT RUNOFF TOTAL RUNOFF
12/5/24
STREET
X:\3970000.all\3979303\Excel\Drainage\3979303 Drainage_Calcs_Template_v2.07.xlsm Page 1 of 4 12/9/2024
Project Name:College and Trilby
Subdivision:College and Trilby Project No.:
Location:Fort Collins Calculated By:ARJ
Design Storm:Checked By:0
Date:
TRAVEL TIME
STREET
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REMARKS
STORM DRAINAGE SYSTEM DESIGN
STANDARD FORM SF-3
(RATIONAL METHOD PROCEDURE)
PIPE
100-Year
DIRECT RUNOFF TOTAL RUNOFF
12/5/24
STREET
Captured by on grade inlet Basin A8
8a A8 0.30 0.86 10.3 0.26 7.62 2.0 0.7 0.09 1.7 334 2.6 2.1 by-pass to DP 2d
8ai 10.3 0.17 7.62 1.3
Piped runoff basin A1-A7 and Basin A8
1.5 16.1 3.56 6.28 22.4 22.4 3.6 0.5 24 193 7.1 0.5
Bypass Flow to dp 4c
7a A7 1.26 0.90 9.9 1.14 7.74 8.8 15.6 2.17 6.39 13.8 2.1 0.33 0.6 305 1.5 3.3
Runoff captured in inlet
7ai 15.6 1.83 6.39 11.7
Bypass Flow to dp 5c
9a A9 0.18 0.86 10.1 0.15 7.70 1.2 0.2 0.03 0.6 305 1.5 3.3
Runoff Captured in Inlet
9ai 10.1 0.12 7.70 0.9
Piped runoff basin A1-A10
1.6 16.6 5.52 6.19 34.1 34.1 5.5 0.5 36 250 7.3 0.6
1.2c C1.2 0.72 0.61 10.7 0.44 7.51 3.3 2.1 0.28 5 108 4.5 0.4
1.2ci 10.7 0.16 7.51 1.2
1.3c C1.3 0.18 0.89 9.8 0.16 7.77 1.2 0.1 0.01 5 80 4.5 0.3 By Passflow to inlet 4c
1.3ci 9.8 0.15 7.77 1.2
Runoff from basin C1.1 onto on grade inlet
1.1c C1.1 3.82 0.70 15.8 2.69 6.34 17.0 15.8 2.98 6.34 18.9 8.9 1.40 1.7 330 2.6 2.1
Runoff Captured by inlet
1.1ci 15.8 1.58 6.34 10.0
X:\3970000.all\3979303\Excel\Drainage\3979303 Drainage_Calcs_Template_v2.07.xlsm Page 2 of 4 12/9/2024
Project Name:College and Trilby
Subdivision:College and Trilby Project No.:
Location:Fort Collins Calculated By:ARJ
Design Storm:Checked By:0
Date:
TRAVEL TIME
STREET
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REMARKS
STORM DRAINAGE SYSTEM DESIGN
STANDARD FORM SF-3
(RATIONAL METHOD PROCEDURE)
PIPE
100-Year
DIRECT RUNOFF TOTAL RUNOFF
12/5/24
STREET
Piped Runoff
2.0 10.7 0.31 7.51 2.3 2.3 7.5 0.5 18 60 3.7 0.3 Tributary Basin C1.2 and C1.3
Piped Runoff
2.1 15.8 1.89 6.34 12.0 Tributary Basin C1.2 and C1.3 and Basin C1.1
On grade runoff from basin C2
2c C2 1.12 0.63 15.6 0.71 6.39 4.5 1.5 0.24 1.8 345 2.7 2.1
2ci 15.6 0.47 6.39 3.0 ByPass to DP 4C
Piped runoff
2.2 15.8 2.36 6.34 14.9 14.9 2.4 1.0 18 290 8.5 0.6 Basin C1.1 -C1.3 and Basin C2
3c C3 2.22 0.95 10.6 2.11 7.53 15.9 11.9 1.58 1.8 125 2.7 0.8 Bypass to DP 4c
3ci 10.6 0.53 7.53 4.0
Piped runoff basins C1.1-C1.3, C2 and C3
2.3 15.8 2.88 6.34 18.3 18.3 2.9 1.0 24 100 8.0 0.2
4.1c C4.1 0.82 0.89 7.4 0.73 8.63 6.3 17.9 3.96 5.93 23.5 8.9 1.50 1.2 300 2.2 2.3
4.1ci 17.9 2.45 5.93 14.5
Piped runoff basins C1.1-C1.3, C2, C3, C4.1
2.4 17.9 5.34 5.93 31.7
Sump Inlet - bypass flows from 4.1c and 8a
4.2c C4.2 1.76 1.00 5.0 1.76 9.95 17.5 20.2 3.60 5.57 20.0
Piped runoff Basins A1-A10 and basin C1.1-C1.3, C2, C3 and C4.1
2.5 20.2 14.45 5.57 80.5
Sump Inlet -by pass flow from 10a
5c C5 1.34 0.85 11.3 1.15 7.34 8.4 13.3 1.18 6.85 8.1
Piped runoff Basins A1-A10 and basin C1.1-C1.3, C2, C3 and C4
2.6 20.2 15.63 5.57 87.0 87.0 15.6 1.5 42 80 13.9 0.1 and Basin C5
Runoff Captured by on grade Alley inlet
1g G1 1.49 0.95 7.7 1.42 8.52 12.1 4.6 0.54 1.5 171 2.4 1.2 Tributary Basin G1
1gi 7.7 0.88 8.52 7.5
Piped Runoff
2.7 20.3 16.51 5.56 91.7 91.7 16.5 2.0 48 150 15.7 0.2 Tributary Basins A1-10 Basin C1.1-C1.3, C4, C5 and G1
Runoff from Alley
2g G2 0.62 1.00 5.0 0.62 9.95 6.2
Runoff Captured by a series of nyloplastic inlets
3g G3 1.06 0.79 11.9 0.84 7.18 6.0
Runoff to inlet in alley at Dp 4g - sump
4g G4 0.82 0.97 6.1 0.79 9.27 7.3 8.8 1.95 8.09 15.8
Piped Runoff
3.1 8.8 2.74 8.09 22.2 22.2 2.7 1.0 36 150 8.5 0.3 Tributary basins G2-G4
X:\3970000.all\3979303\Excel\Drainage\3979303 Drainage_Calcs_Template_v2.07.xlsm Page 3 of 4 12/9/2024
Project Name:College and Trilby
Subdivision:College and Trilby Project No.:
Location:Fort Collins Calculated By:ARJ
Design Storm:Checked By:0
Date:
TRAVEL TIME
STREET
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REMARKS
STORM DRAINAGE SYSTEM DESIGN
STANDARD FORM SF-3
(RATIONAL METHOD PROCEDURE)
PIPE
100-Year
DIRECT RUNOFF TOTAL RUNOFF
12/5/24
STREET
Runoff from Alley Drains into Chase
1e E1 0.42 1.00 5.8 0.42 9.43 4.0
Runoff from Cu-de-Sac and Runoff from chase
2e E2 0.73 0.96 5.3 0.70 9.79 6.8 12.5 1.12 7.05 7.9 7.9 1.1 1.0 24 30 6.5 0.1 Tributary Runoff basin E1 and E2
Runoff from sump inlet
3e E3 0.23 0.96 6.9 0.22 8.86 1.9 1.9 0.2 1.0 12 65 4.6 0.1
Tributary runoff from basin E1-E3
4.1 6.9 2.08 8.86 18.5 18.5 2.1 1.0 18 39 10.5 0.1
J910B OFFSITE Runoff from Trilby Road - picked up by 15 ft PR and 10 ft type r inlets
5.1 60.49 Runoff entered in from SWMM MODEL from J910B
1b B1 0.63 0.99 5.0 0.63 9.95 6.3
Offsite Runoff
5.2 66.8 Offsite runoff + basin B1
2b B2 1.17 0.36 12.2 0.42 7.11 3.0
5.3 69.7 Offsite runoff + basin B1 and B2
L367_Orifice
P367 Outfall 0.17 Runoff entered in from SWMM MODEL
Sump inlet, Recives by pass flow from basin A7
2d D2 0.50 0.89 6.4 0.44 9.09 4.0 7.3 0.51 8.67 4.4
Offsite runoff from pond P367, Offsite runoff from Trilby Road
6.1 74.3 Onsite basins B1 and B2 and D2
1d D1 0.29 0.96 5.0 0.28 9.95 2.8
Offsite runoff from pond P367, Offsite runoff from Trilby Road
6.2 77.1 Onsite basins B1 and B2 and D2 and D1
Notes:
Street and Pipe C*A values are determined by Q/i using the catchment's intensity value.
X:\3970000.all\3979303\Excel\Drainage\3979303 Drainage_Calcs_Template_v2.07.xlsm Page 4 of 4 12/9/2024
Subdivision:College and Trilby Project Name:College and Trilby
Location:Fort Collins Project No.:
Calculated By:ARJ
Checked By:0
Date:12/5/24
Tributary Area Length Width Slope % Imperv N-Imperv N-Perv Store Imperv. Dstore perv. Zero % imperv. Storage (max)Storage (min)Decay Rate
Sub-basin
B820 26.52 500.09 2310.00 3.90%5.0%0.016 0.25 0.1 0.3 1 0.51 0.5 6.48
B910 15.78 339.28 2026.00 3.00%20.0%0.016 0.25 0.1 0.3 1 0.51 0.5 6.48
B830 7.04 473.45 648.00 3.90%45.0%0.016 0.25 0.1 0.3 1 0.51 0.5 6.48
B910A 3.06 533.17 250.00 2.00%74.0%0.016 0.25 0.1 0.3 1 0.51 0.5 6.48
B876 17.03 420.06 1766.00 4.10%60.0%0.016 0.25 0.1 0.3 1 0.51 0.5 6.48
Subdivision:College and Trilby Project Name:College and Trilby
Location:Fort Collins Project No.:
Calculated By:ARJ
Checked By:0
Date:12/5/24
A1 1.90 100%0.15 7.8%40%0.00 0.0%90%0.14 6.4%2%1.62 1.7%14.3%
A2 1.79 100%0.48 27.0%40%0.00 0.0%90%0.48 24.0%2%0.83 0.9%51.0%
A3 1.62 100%0.42 26.1%40%0.09 2.1%90%0.15 8.4%2%1.05 1.3%36.7%
A4 0.42 100%0.25 58.4%40%0.00 0.0%90%0.00 0.0%2%0.18 0.8%58.4%
A5 0.75 100%0.36 47.9%40%0.00 0.0%90%0.17 20.5%2%0.22 0.6%68.4%
A6 0.47 100%0.35 72.9%40%0.00 0.0%90%0.00 0.0%2%0.13 0.5%72.9%
A7 1.26 100%0.45 35.7%40%0.00 0.0%90%0.40 28.6%2%0.41 0.7%64.3%
A8 0.30 100%0.20 64.9%40%0.00 0.0%90%0.00 0.0%2%0.11 0.7%64.9%
A9 0.18 100%0.11 65.0%40%0.00 0.0%90%0.00 0.0%2%0.06 0.7%65.0%
C1.1 3.82 100%1.16 30.3%40%0.00 0.0%90%0.55 13.1%2%2.11 1.1%43.4%
C1.2 0.72 100%0.16 22.9%40%0.00 0.0%90%0.11 13.9%2%0.44 1.2%36.8%
C1.3 0.18 100%0.07 38.8%40%0.00 0.0%90%0.05 26.7%2%0.06 0.6%65.6%
C2 1.12 100%0.45 40.4%40%0.00 0.0%90%0.00 0.0%2%0.67 1.2%40.4%
C3 2.22 100%0.88 39.7%40%0.00 0.0%90%0.74 29.9%2%0.60 0.5%69.6%
C4.1 0.82 100%0.47 57.1%40%0.00 0.0%90%0.09 9.7%2%0.26 0.6%66.8%
C4.2 1.76 100%0.51 29.2%40%0.00 0.0%90%0.43 21.9%2%0.81 0.9%51.2%
C5 1.34 100%0.86 64.3%40%0.00 0.0%90%0.00 0.0%2%0.48 0.7%64.3%
G1 1.49 100%0.73 49.1%40%0.00 0.0%90%0.41 24.5%2%0.35 0.5%73.5%
G2 0.62 100%0.29 46.3%40%0.00 0.0%90%0.25 36.5%2%0.08 0.3%82.8%
G3 1.06 100%0.16 15.5%40%0.00 0.0%90%0.48 40.5%2%0.42 0.8%56.0%
G4 0.82 100%0.50 60.6%40%0.00 0.0%90%0.14 15.5%2%0.18 0.4%76.1%
SWMM Basin CT-1 24.68 100%9.03 36.6%40%0.09 0.1%90%4.59 16.7%2%11.07 0.9%53.4%
B1 0.63 100%0.28 43.7%40%0.00 0.0%90%0.23 32.1%2%0.13 0.4%75.9%
B2 1.17 100%0.06 5.1%40%0.00 0.0%90%0.00 0.0%2%1.11 1.9%5.1%
D1 0.29 100%0.22 75.6%40%0.00 0.0%90%0.00 0.0%2%0.07 0.5%75.6%
D2 0.50 100%0.26 53.0%40%0.00 0.0%90%0.08 13.9%2%0.16 0.6%66.9%
E1 0.42 100%0.20 47.0%40%0.00 0.0%90%0.16 34.1%2%0.06 0.3%81.0%
E2 0.73 100%0.57 77.7%40%0.00 0.0%90%0.00 0.0%2%0.16 0.4%77.7%
E3 0.23 100%0.18 77.6%40%0.00 0.0%90%0.00 0.0%2%0.05 0.4%77.6%
E4 0.17 100%0.08 46.6%40%0.00 0.0%90%0.03 15.2%2%0.06 0.7%61.8%
E5 0.38 100%0.11 28.0%40%0.00 0.0%90%0.03 8.1%2%0.24 1.3%36.1%
E6 0.86 100%0.04 4.4%40%0.00 0.0%90%0.00 0.0%2%0.82 1.9%4.4%
SWMM Basin CT-2 5.37 100%1.99 37.0%40%0.00 0.0%90%0.52 8.8%2%2.86 1.1%45.7%
Sub-Basin F1 1.20 100%0.07 6.0%40%0.00 0.0%90%0.32 24.3%2%0.81 1.3%31.7%
SWMM Basin CT-3 1.20 100%0.07 6.0%90%0.00 0.0%90%0.32 24.3%2%0.81 1.3%31.7%
Sub-Basin H1 5.81 100%0.20 3.5%40%0.00 0.0%90%0.12 1.9%90%5.48 1.9%7.3%
SWMM Basin CT-4 5.81 100%0.20 3.5%40%0.00 0.0%90%0.12 1.9%90%5.48 1.9%7.3%
Subdivision:College and Trilby Project Name:College and Trilby
Location:Fort Collins Project No.:
Calculated By:ARJ
Checked By:0
Date:12/5/24
Tributary Area Length Width Slope % Imperv N-Imperv N-Perv Store Imperv. Dstore perv. Zero % imperv. Storage (max)Storage (min) Decay Rate
Sub-basin
CT-1 24.68 587.76 1829.09 1.53%53.4%0.016 0.25 0.1 0.3 1 0.51 0.5 6.48
CT-2 5.37 307.40 761.18 0.75%45.7%0.016 0.25 0.1 0.3 1 0.51 0.5 6.48
CT-3 1.20 338.70 154.85 2.40%31.7%0.016 0.25 0.1 0.3 1 0.51 0.5 6.48
CT-4 5.81 353.30 715.82 0.50%7.3%0.016 0.25 0.1 0.3 1 0.51 0.5 6.48
OF1 0.53 156.40 147.25 0.50%12.2%0.016 0.25 0.1 0.3 1 0.51 0.5 6.48
OS1 0.74 186.30 172.44 0.50%2.0%0.016 0.25 0.1 0.3 1 0.51 0.5 6.48
OS2 2.03 403.00 219.72 3.97%2.0%0.016 0.25 0.1 0.3 1 0.51 0.5 6.48
OS3 0.32 115.00 121.16 3.94%2.0%0.016 0.25 0.1 0.3 1 0.51 0.5 6.48
OS4 0.40 129.00 134.97 3.73%2.0%0.016 0.25 0.1 0.3 1 0.51 0.5 6.48
OS5 1.69 484.00 152.40 2.09%2.0%0.016 0.25 0.1 0.3 1 0.51 0.5 6.48
OS6 0.88 231.00 165.42 3.73%78.3%0.016 0.25 0.1 0.3 1 0.51 0.5 6.48
B840 11.79 300.17 1710.37 3.00%45.0%0.016 0.25 0.1 0.3 1 0.51 0.5 6.48
B830 7.82 473.45 719.26 3.90%45.0%0.016 0.25 0.1 0.3 1 0.51 0.5 6.48
B930 4.71 399.91 512.81 3.00%31.2%0.016 0.25 0.1 0.3 1 0.51 0.5 6.48
B910A 2.99 533.17 244.35 2.00%74.0%0.016 0.25 0.1 0.3 1 0.51 0.5 6.48
B910C 1.30 83.39 681.60 2.30%90.0%0.016 0.25 0.1 0.3 1 0.51 0.5 6.48
B910D 0.46 160.30 126.16 1.50%90.0%0.016 0.25 0.1 0.3 1 0.51 0.5 6.48
B850 17.24 419.98 1787.65 4.10%10.0%0.016 0.25 0.1 0.3 1 0.51 0.5 6.48
B876 16.97 420.06 1759.42 4.10%60.0%0.016 0.25 0.1 0.3 1 0.51 0.5 6.48
Basins Total
Weighted %
Imp.Basin ID Total Area (ac) % Imp. Area (ac)Weighted %
Imp.Area (ac)
SWMM INPUTS
39823.00
PROPOSED - SWMM INPUTS
Basin inputs City of Fort Collins Default Inputs City of Fort Collins Horton inputs
INTERIM - SWMM INPUTS
Paved Roads and Walks Gravel Roofs
PROPOSED ONSITE COMPOSITE SWMM IMPERVIOUS VALUES
39823.00
PROPOSED SWMM INPUTS
39823.00
Weighted %
Imp.
Sub-Basins
Sub-Basins
% Imp.Area (ac)Weighted %
Imp.% Imp.
* Updated Offsite Basins - kepth Lengths the same and updated area
Lawns
% Imp.Area (ac)Weighted %
Imp.
X:\3970000.all\3979303\Excel\Drainage\3979303 Drainage_Calcs_Template_v2.07.xlsm Page 1 of 1 12/9/2024
Project Name:College and Trilby
Subdivision:College and Trilby Project No.
Location:Fort Collins By:ARJ
Design Storm:0
Date:12/5/24
WILSON - Interim SC_100YearPROP JR - Proposed College and Trilby SC_100YearPROP
Name Basin Area (ac)Outlet Name Basin Area (ac)Diff Outlet Notes:
B100 1.88 J100 B100 1.88 0 J100 ---
B110 8.65 J100 B110 8.65 0 J100 ---
B300 1.2 J300 B300 1.2 0 J300 ---
B310 20.25 J316 B310 20.25 0 J316 ---
B320 11.31 J320 B320 11.31 0 J320 ---
B330 39.65 J330 B330 39.65 0 J330 ---
B340 31.27 J346 B340 31.27 0 J346 ---
B350 21.96 J350 B350 21.96 0 J350 ---
B360 2.34 J360 B360 2.34 0 J360 ---
B370 30.18 J360 B370 30.18 0 J360 ---
B380 4.9 J360 B380 4.9 0 J360 ---
B390 10.32 J390 B390 10.32 0 J390 ---
B400 22.57 J390 B400 22.57 0 J390 ---
B410 8.18 J410 B410 8.18 0 J410 ---
B420 5.85 P324 B420 5.85 0 P324 ---
B430 6.23 P324 B430 6.23 0 P324 ---
B440 9.56 P324 B440 9.56 0 P324 ---
B445 0.52 J452-TypeR B445 0.52 0 J452-TypeR ---
B450 3.2 J450 B450 3.2 0 J450 ---
B455 2.45 J508 B455 2.45 0 J508 ---
B460 2.55 J456 B460 2.55 0 J456 ---
B465 2.3 J456-TypeR B465 2.3 0 J456-TypeR ---
B470 3.93 J470 B470 3.93 0 J470 ---
B480 4.53 P343 B480 4.53 0 P343 ---
B490 2.12 P343 B490 2.12 0 P343 ---
B500 1.92 J500 B500 1.92 0 J500 ---
B510 0.92 J510 B510 0.92 0 J510 ---
B520 8.43 J520 B520 8.43 0 J520 ---
B530 1.95 J525 B530 1.95 0 J525 ---
B540 3.05 J540 B540 3.05 0 J540 ---
B600 12.46 J600 B600 12.46 0 J600 ---
B610 8.39 J600 B610 8.39 0 J600 ---
B620 5.29 J620 B620 5.29 0 J620 ---
B630 8.65 J630 B630 8.65 0 J630 ---
B640 6.92 J640 B640 6.92 0 J640 ---
B650 9.58 J650 B650 9.58 0 J650 ---
B660 1.75 P385 B660 1.75 0 P385 ---
B670 0.82 P384 B670 0.82 0 P384 ---
B680 2.02 P383 B680 2.02 0 P383 ---
B690 20 P382 B690 20 0 P382 ---
B700 42.95 P386 B700 42.95 0 P386 ---
B710 12.5 J710 B710 12.5 0 J710 ---
B720 26.49 J710 B720 26.49 0 J710 ---
B730 4.19 J730 B730 4.19 0 J730 ---
B740 1.75 J740 B740 1.75 0 J740 ---
B750 5.39 J740 B750 5.39 0 J740 ---
B760 1.2 J760 B760 1.2 0 J760 ---
B770 2.97 J770 B770 2.97 0 J770 ---
B770A 0.36 J770A B770A 0.36 0 J770A ---
B770B 1.52 J770B B770B 1.52 0 J770B ---
B780 2.27 J770 B780 2.27 0 J770 ---
B790 14.69 P790 B790 14.69 0 P790 ---
B800 25.72 J804 B800 25.72 0 J804 ---
B805 38.42 P400 B805 38.42 0 P400 ---
B810 22.95 J810 B810 22.95 0 J810 ---
B820 26.52 P363 Basin Removed
B830 7.43 J830 B830 7.82 -0.39 J830 Updated per site W. Site Boundary
B840 11.06 J840 B840 11.79 -0.73 J840 Updated per site W. Site Boundary
B850 16.94 P375 B850 17.24 -0.3 P375 Updated per site N. Site Boundary
B870 2.69 J870 B870 2.69 0 J870 ---
B874 5.38 P874 B874 5.38 0 P874 ---
B876 17.03 P876 B876 16.97 0.06 P876 Updated per site W. Site Boundary
B880 15.67 J880 B880 15.67 0 J880 ---
B900 2.17 J900 B900 2.17 0 J900 ---
B900A 0.48 J900A B900A 0.48 0 J900A ---
B900B 0.56 J900B B900B 0.56 0 J900B ---
B910 15.74 P366 B910 Basin Removed
B910A 3.06 P367 B910A 2.99 0.07 P367 Updated per SE Site Boundary
B910B 0.28 J910B B910B Basin Removed
B910C 1.34 J910C B910C 1.3 0.04 J910C Updated per E Site Boundary
B910D 0.46 J910D B910D 0.46 0 J910D ---
B920A 3.82 J920A B920A 3.82 0 J920A ---
B920B 0.99 J920B B920B 0.99 0 J920B ---
B920C 1.71 J920C B920C 1.71 0 J920C ---
B930 7.06 P930 B930 4.71 2.35 P930 ---
B940 15.47 P940 B940 15.47 0 P940 ---
B950 2.56 P950 B950 2.56 0 P950 ---
B970 8.66 P970 B970 8.66 0 P970 ---
CT-1 24.68 P363 On-site treated in Isolator Rows
CT-2 5.37 P366 Onsite treated in WQ Pond
CT-3 1.2 J910 Channel between P366 and P363
CT-4 5.81 P363 Open space/ P363
OF1 0.53 J829 W. Overflow channel
OS1 0.74 J931 W. Trilby RD
OS2 2.03 J931 W. Trilby RD
OS3 0.32 J932 W. Trilby RD
OS4 0.4 P940 W. Trilby RD
OS5 1.69 J363 S. College Ave.
OS6 0.88 J374 S. College Ave.
Total (ac).720.5 720.5
SWMM Model Comparison Table
(SWMM MODEL COMP. Interim SC_100YearPROP Vs. Proposed College and Trilby SC_100YearPROP )
100-Year
39823.00
X:\3970000.all\3979303\Excel\Drainage\3979303 Drainage_Calcs_Template_v2.07.xlsm Page 1 of 2 12/9/2024
X:\3970000.all\3979303\Excel\Drainage\3979303 Drainage_Calcs_Template_v2.07.xlsm Page 2 of 2 12/9/2024
Subdivision:College and Trilby Project Name:College and Trilby
Location:Fort Collins Project No.:39823.00
By:ARJ
Volume=1/3 x Depth x (A+B+(A*B)^0.5)Checked By:0
A - Upper Surface Date:12/5/24
B - Lower Surface
Stage Stage Elevation Stage Surface Area Stage Volume Cumulative Volume Cumulative Volume
(square feet)(cubic feet)(cubic feet)(acre feet)
0.00 4998.87 0 0 0 0.00
0.13 4999.00 207 9 9 0.00
1.13 5000.00 20,791 7,691 7,700 0.18
2.13 5001.00 54,621 36,370 44,070 1.01
3.13 5002.00 69,423 61,874 105,944 2.43
4.13 5003.00 77,422 73,386 179,330 4.12
5.13 5004.00 84,528 80,949 260,279 5.98
6.13 5005.00 91,786 88,132 348,411 8.00
7.13 5006.00 99,265 95,501 443,912 10.19
8.13 5007.00 107,023 103,119 547,031 12.56
9.13 5008.00 115,553 111,261 658,292 15.11
10.13 5009.00 122,656 119,087 777,379 17.85
Volume (acre feet)Volume Water Surface Elevation Stage
100-Year Detention 9.78 5006.04 7.17
*Volume modeled in SWMM
POND VOLUME CALCULATIONS
POND P363
X:\3970000.all\3979303\Excel\Drainage\3979303 Drainage_Calcs_Template_v2.07.xlsm Page 1 of 2 12/11/2024
Subdivision:College and Trilby Project Name:College and Trilby
Location:Fort Collins Project No.39823.00
By:ARJ
Checked By:0
Date:12/5/24
POND VOLUME CALCULATIONS
4998.00
5000.00
5002.00
5004.00
5006.00
5008.00
5010.00
-2.00 0.00 2.00 4.00 6.00 8.00 10.00 12.00 14.00 16.00 18.00 20.00
El
e
v
a
t
i
o
n
(
f
t
)
Pond Volume (ac-ft)
Pond Stage-Storage
X:\3970000.all\3979303\Excel\Drainage\3979303 Drainage_Calcs_Template_v2.07.xlsm Page 2 of 2 12/11/2024
Subdivision:College and Trilby Project Name:College and Trilby
Location:Fort Collins Project No.:39823.00
By:ARJ
Volume=1/3 x Depth x (A+B+(A*B)^0.5)Checked By:0
A - Upper Surface Date:12/5/24
B - Lower Surface
Stage Stage Elevation Stage Surface Area Stage Volume Cumulative Volume Cumulative Volume
(square feet)(cubic feet)(cubic feet)(acre feet)
0.00 5019.25 0 0 0 0.00
0.75 5020.00 3,204 801 801 0.02
1.75 5021.00 9,840 6,220 7,021 0.16
2.75 5022.00 13,392 11,570 18,591 0.43
3.75 5023.00 15,949 14,652 33,243 0.76
4.75 5024.00 18,716 17,314 50,557 1.16
5.75 5025.00 22,031 20,351 70,908 1.63
6.75 5026.00 25,665 23,825 94,733 2.17
Volume (acre feet)Volume Water Surface Elevation Stage
Water Quality 0.444 5022.01 2.76
100-Year 1.41 5024.52 5.27
* Volume Modeled in SWMM
POND VOLUME CALCULATIONS
POND P366
X:\3970000.all\3979303\Excel\Drainage\3979303 Drainage_Calcs_Template_v2.07.xlsm Page 1 of 2 12/9/2024
Subdivision:College and Trilby Project Name:College and Trilby
Location:Fort Collins Project No.39823.00
By:ARJ
Checked By:0
Date:12/5/24
POND VOLUME CALCULATIONS
5018.00
5019.00
5020.00
5021.00
5022.00
5023.00
5024.00
5025.00
5026.00
5027.00
0.00 0.50 1.00 1.50 2.00 2.50
El
e
v
a
t
i
o
n
(
f
t
)
Pond Volume (ac-ft)
Pond Stage-Storage
X:\3970000.all\3979303\Excel\Drainage\3979303 Drainage_Calcs_Template_v2.07.xlsm Page 2 of 2 12/9/2024
5 Year Drain Time - SWMM
Pond 366 Drain Time
5 Year Drain Time - SWMM
Pond P363 Drain Time
100 Year Drain Time - SWMM
Pond 366 Drain Time
100 Year Drain Time - SWMM
Pond P363 Drain Time
College & Trilby Multi-Family Community
Final Drainage Report
APPENDIX C – HYDRAULIC CALCULATIONS
Analysis of Trapezoidal Channel (Grass-Lined uses SCS Method)
NRCS Vegetal Retardance (A, B, C, D, or E)A, B, C, D, or E =
Manning's n (Leave cell D16 blank to manually enter an n value)n =0.013
O 0.0115
Bottom Width B =1.875 ft
Left Side Slope Z1 =33.33 ft/ft
Right Side Sloe Z2 =33.33 ft/ft
Check one of the following soil types:
MAX MAX
Non-Cohesive 5.0 fps 0.60
Cohesive 7.0 fps 0.80
Paved N/A N/A
Minor Storm Major Storm
TMAX =12.00 24.00 ft
dMAX =0.18 0.36 ft
Allowable Channel Capacity Based On Channel Geometry Minor Storm Major Storm
Qallow =2.6 16.8 cfs
dallow =0.15 0.33 ft
Water Depth in Channel Based On Design Peak Flow
Qo =2.3 12.1 cfs
Water Depth d =0.14 0.29 ft
MHFD-Inlet, Version 5.03 (August 2023)
AREA INLET IN A SWALE
This worksheet uses the NRCS vegetal
retardance method to determine
Manning's n for grass-lined channels.
An override Manning's n can be
entered for other channel materials.
Minor storm max. allowable capacity GOOD - greater than the design flow given on sheet 'Inlet Management'
Choose One:
Non-Cohesive
Cohesive
Paved
3979303 MHFD-Inlet_v5.03.xlsm, Inlet DP 1g 12/5/2024, 10:13 AM
MHFD-Inlet, Version 5.03 (August 2023)
AREA INLET IN A SWALE
College and Trilby
Inlet DP 1g
Inlet Design Information (Input)
Type of Inlet Inlet Type =
Angle of Inclined Grate (must be <= 30 degrees)θ =0.00 degrees
Width of Grate W =1.88 ft
Length of Grate L =12.00 ft
RATIO 0.70
B 0.00
f 0.50
d N/A
o 0.64
w 2.05
MINOR MAJOR
Water Depth at Inlet (for depressed inlets, 1 foot is added for depression)d =0.14 0.29
Total Inlet Interception Capacity (assumes clogged condition)Qa =2.6 7.5 cfs
Bypassed Flow Qb =0.0 4.6 cfs
Capture Percentage = Qa/Qo C% =100 62 %
User-DefinedUser-Defined
4 - On grade
CDOT type 13
Inlet
3979303 MHFD-Inlet_v5.03.xlsm, Inlet DP 1g 12/5/2024, 10:13 AM
Project:
Inlet ID:
Gutter Geometry:
Maximum Allowable Width for Spread Behind Curb TBACK =13.5 ft
Side Slope Behind Curb (leave blank for no conveyance credit behind curb)SBACK =0.020 ft/ft
Manning's Roughness Behind Curb (typically between 0.012 and 0.020)nBACK =0.016
Height of Curb at Gutter Flow Line HCURB =6.00 inches
Distance from Curb Face to Street Crown TCROWN =18.0 ft
Gutter Width W =2.00 ft
Street Transverse Slope SX =0.020 ft/ft
Gutter Cross Slope (typically 2 inches over 24 inches or 0.083 ft/ft)SW =0.083 ft/ft
Street Longitudinal Slope - Enter 0 for sump condition SO =0.031 ft/ft
Manning's Roughness for Street Section (typically between 0.012 and 0.020)nSTREET =0.016
Minor Storm Major Storm
Max. Allowable Spread for Minor & Major Storm TMAX =12.0 18.0 ft
Max. Allowable Depth at Gutter Flowline for Minor & Major Storm dMAX =6.0 8.2 inches
Allow Flow Depth at Street Crown (check box for yes, leave blank for no)
MINOR STORM Allowable Capacity is based on Spread Criterion Minor Storm Major Storm
MAJOR STORM Allowable Capacity is based on Spread Criterion Qallow =8.3 22.0 cfs
Minor storm max. allowable capacity GOOD - greater than the design peak flow of 0.55 cfs on sheet 'Inlet Management'
MHFD-Inlet, Version 5.03 (August 2023)
ALLOWABLE CAPACITY FOR ONE-HALF OF STREET (Minor & Major Storm)
(Based on Regulated Criteria for Maximum Allowable Flow Depth and Spread)
3979303 MHFD-Inlet_v5.03.xlsm, Inlet DP 4a 12/5/2024, 10:13 AM
Design Information (Input)MINOR MAJOR
Type of Inlet Type =
Local Depression (additional to continuous gutter depression 'a')aLOCAL =2.0 2.0 inches
Total Number of Units in the Inlet (Grate or Curb Opening)No =3 3
Length of a Single Unit Inlet (Grate or Curb Opening)Lo =3.00 3.00 ft
Width of a Unit Grate (cannot be greater than W, Gutter Width)Wo =1.73 1.73 ft
Clogging Factor for a Single Unit Grate (typical min. value = 0.5)Cf (G) =0.50 0.50
Clogging Factor for a Single Unit Curb Opening (typical min. value = 0.1)Cf (C) =0.10 0.10
Street Hydraulics: OK - Q < Allowable Street Capacity'MINOR MAJOR
Total Inlet Interception Capacity Q =0.5 2.0 cfs
Total Inlet Carry-Over Flow (flow bypassing inlet)Qb =0.0 0.4 cfs
Capture Percentage = Qa/Qo C% =100 85 %
INLET ON A CONTINUOUS GRADE
MHFD-Inlet, Version 5.03 (August 2023)
User-Defined CombinationUser-Defined Combination
3979303 MHFD-Inlet_v5.03.xlsm, Inlet DP 4a 12/5/2024, 10:17 AM
Project:
Inlet ID:
Gutter Geometry:
Maximum Allowable Width for Spread Behind Curb TBACK =13.5 ft
Side Slope Behind Curb (leave blank for no conveyance credit behind curb)SBACK =0.020 ft/ft
Manning's Roughness Behind Curb (typically between 0.012 and 0.020)nBACK =0.016
Height of Curb at Gutter Flow Line HCURB =6.00 inches
Distance from Curb Face to Street Crown TCROWN =18.0 ft
Gutter Width W =2.00 ft
Street Transverse Slope SX =0.020 ft/ft
Gutter Cross Slope (typically 2 inches over 24 inches or 0.083 ft/ft)SW =0.083 ft/ft
Street Longitudinal Slope - Enter 0 for sump condition SO =0.023 ft/ft
Manning's Roughness for Street Section (typically between 0.012 and 0.020)nSTREET =0.016
Minor Storm Major Storm
Max. Allowable Spread for Minor & Major Storm TMAX =12.0 18.0 ft
Max. Allowable Depth at Gutter Flowline for Minor & Major Storm dMAX =6.0 8.2 inches
Allow Flow Depth at Street Crown (check box for yes, leave blank for no)
MINOR STORM Allowable Capacity is based on Spread Criterion Minor Storm Major Storm
MAJOR STORM Allowable Capacity is based on Spread Criterion Qallow =7.1 19.0 cfs
Minor storm max. allowable capacity GOOD - greater than the design peak flow of 2.59 cfs on sheet 'Inlet Management'
MHFD-Inlet, Version 5.03 (August 2023)
ALLOWABLE CAPACITY FOR ONE-HALF OF STREET (Minor & Major Storm)
(Based on Regulated Criteria for Maximum Allowable Flow Depth and Spread)
3979303 MHFD-Inlet_v5.03.xlsm, Inlet DP 3a 12/5/2024, 10:13 AM
Design Information (Input)MINOR MAJOR
Type of Inlet Type =
Local Depression (additional to continuous gutter depression 'a')aLOCAL =2.0 2.0 inches
Total Number of Units in the Inlet (Grate or Curb Opening)No =4 4
Length of a Single Unit Inlet (Grate or Curb Opening)Lo =3.00 3.00 ft
Width of a Unit Grate (cannot be greater than W, Gutter Width)Wo =1.73 1.73 ft
Clogging Factor for a Single Unit Grate (typical min. value = 0.5)Cf (G) =0.50 0.50
Clogging Factor for a Single Unit Curb Opening (typical min. value = 0.1)Cf (C) =0.10 0.10
Street Hydraulics: OK - Q < Allowable Street Capacity'MINOR MAJOR
Total Inlet Interception Capacity Q =2.6 12.1 cfs
Total Inlet Carry-Over Flow (flow bypassing inlet)Qb =0.0 5.5 cfs
Capture Percentage = Qa/Qo C% =99 69 %
INLET ON A CONTINUOUS GRADE
MHFD-Inlet, Version 5.03 (August 2023)
User-Defined CombinationUser-Defined Combination
3979303 MHFD-Inlet_v5.03.xlsm, Inlet DP 3a 12/5/2024, 10:13 AM
Project:
Inlet ID:
Gutter Geometry:
Maximum Allowable Width for Spread Behind Curb TBACK =13.5 ft
Side Slope Behind Curb (leave blank for no conveyance credit behind curb)SBACK =0.020 ft/ft
Manning's Roughness Behind Curb (typically between 0.012 and 0.020)nBACK =0.016
Height of Curb at Gutter Flow Line HCURB =6.00 inches
Distance from Curb Face to Street Crown TCROWN =27.0 ft
Gutter Width W =2.00 ft
Street Transverse Slope SX =0.020 ft/ft
Gutter Cross Slope (typically 2 inches over 24 inches or 0.083 ft/ft)SW =0.083 ft/ft
Street Longitudinal Slope - Enter 0 for sump condition SO =0.017 ft/ft
Manning's Roughness for Street Section (typically between 0.012 and 0.020)nSTREET =0.016
Minor Storm Major Storm
Max. Allowable Spread for Minor & Major Storm TMAX =12.0 27.0 ft
Max. Allowable Depth at Gutter Flowline for Minor & Major Storm dMAX =6.0 9.2 inches
Allow Flow Depth at Street Crown (check box for yes, leave blank for no)
MINOR STORM Allowable Capacity is based on Spread Criterion Minor Storm Major Storm
MAJOR STORM Allowable Capacity is based on Spread Criterion Qallow =6.1 47.8 cfs
Minor storm max. allowable capacity GOOD - greater than the design peak flow of 1.15 cfs on sheet 'Inlet Management'
MHFD-Inlet, Version 5.03 (August 2023)
ALLOWABLE CAPACITY FOR ONE-HALF OF STREET (Minor & Major Storm)
(Based on Regulated Criteria for Maximum Allowable Flow Depth and Spread)
3979303 MHFD-Inlet_v5.03.xlsm, Inlet DP 5a 12/5/2024, 10:13 AM
Design Information (Input)MINOR MAJOR
Type of Inlet Type =
Local Depression (additional to continuous gutter depression 'a')aLOCAL =2.0 2.0 inches
Total Number of Units in the Inlet (Grate or Curb Opening)No =3 3
Length of a Single Unit Inlet (Grate or Curb Opening)Lo =3.00 3.00 ft
Width of a Unit Grate (cannot be greater than W, Gutter Width)Wo =1.73 1.73 ft
Clogging Factor for a Single Unit Grate (typical min. value = 0.5)Cf (G) =0.50 0.50
Clogging Factor for a Single Unit Curb Opening (typical min. value = 0.1)Cf (C) =0.10 0.10
Street Hydraulics: OK - Q < Allowable Street Capacity'MINOR MAJOR
Total Inlet Interception Capacity Q =1.2 4.6 cfs
Total Inlet Carry-Over Flow (flow bypassing inlet)Qb =0.0 1.5 cfs
Capture Percentage = Qa/Qo C% =100 75 %
INLET ON A CONTINUOUS GRADE
MHFD-Inlet, Version 5.03 (August 2023)
User-Defined CombinationUser-Defined Combination
3979303 MHFD-Inlet_v5.03.xlsm, Inlet DP 5a 12/5/2024, 10:13 AM
Project:
Inlet ID:
Gutter Geometry:
Maximum Allowable Width for Spread Behind Curb TBACK =13.5 ft
Side Slope Behind Curb (leave blank for no conveyance credit behind curb)SBACK =0.020 ft/ft
Manning's Roughness Behind Curb (typically between 0.012 and 0.020)nBACK =0.016
Height of Curb at Gutter Flow Line HCURB =6.00 inches
Distance from Curb Face to Street Crown TCROWN =27.0 ft
Gutter Width W =2.00 ft
Street Transverse Slope SX =0.020 ft/ft
Gutter Cross Slope (typically 2 inches over 24 inches or 0.083 ft/ft)SW =0.083 ft/ft
Street Longitudinal Slope - Enter 0 for sump condition SO =0.017 ft/ft
Manning's Roughness for Street Section (typically between 0.012 and 0.020)nSTREET =0.016
Minor Storm Major Storm
Max. Allowable Spread for Minor & Major Storm TMAX =12.0 27.0 ft
Max. Allowable Depth at Gutter Flowline for Minor & Major Storm dMAX =6.0 9.2 inches
Allow Flow Depth at Street Crown (check box for yes, leave blank for no)
MINOR STORM Allowable Capacity is based on Spread Criterion Minor Storm Major Storm
MAJOR STORM Allowable Capacity is based on Spread Criterion Qallow =6.1 47.8 cfs
Minor storm max. allowable capacity GOOD - greater than the design peak flow of 0.78 cfs on sheet 'Inlet Management'
MHFD-Inlet, Version 5.03 (August 2023)
ALLOWABLE CAPACITY FOR ONE-HALF OF STREET (Minor & Major Storm)
(Based on Regulated Criteria for Maximum Allowable Flow Depth and Spread)
3979303 MHFD-Inlet_v5.03.xlsm, Inlet DP 6a 12/5/2024, 10:13 AM
Design Information (Input)MINOR MAJOR
Type of Inlet Type =
Local Depression (additional to continuous gutter depression 'a')aLOCAL =2.0 2.0 inches
Total Number of Units in the Inlet (Grate or Curb Opening)No =3 3
Length of a Single Unit Inlet (Grate or Curb Opening)Lo =3.00 3.00 ft
Width of a Unit Grate (cannot be greater than W, Gutter Width)Wo =1.73 1.73 ft
Clogging Factor for a Single Unit Grate (typical min. value = 0.5)Cf (G) =0.50 0.50
Clogging Factor for a Single Unit Curb Opening (typical min. value = 0.1)Cf (C) =0.10 0.10
Street Hydraulics: OK - Q < Allowable Street Capacity'MINOR MAJOR
Total Inlet Interception Capacity Q =0.8 3.6 cfs
Total Inlet Carry-Over Flow (flow bypassing inlet)Qb =0.0 0.6 cfs
Capture Percentage = Qa/Qo C% =100 85 %
INLET ON A CONTINUOUS GRADE
MHFD-Inlet, Version 5.03 (August 2023)
User-Defined CombinationUser-Defined Combination
3979303 MHFD-Inlet_v5.03.xlsm, Inlet DP 6a 12/5/2024, 10:13 AM
Project:
Inlet ID:
Gutter Geometry:
Maximum Allowable Width for Spread Behind Curb TBACK =13.5 ft
Side Slope Behind Curb (leave blank for no conveyance credit behind curb)SBACK =0.020 ft/ft
Manning's Roughness Behind Curb (typically between 0.012 and 0.020)nBACK =0.016
Height of Curb at Gutter Flow Line HCURB =6.00 inches
Distance from Curb Face to Street Crown TCROWN =27.0 ft
Gutter Width W =2.00 ft
Street Transverse Slope SX =0.020 ft/ft
Gutter Cross Slope (typically 2 inches over 24 inches or 0.083 ft/ft)SW =0.083 ft/ft
Street Longitudinal Slope - Enter 0 for sump condition SO =0.020 ft/ft
Manning's Roughness for Street Section (typically between 0.012 and 0.020)nSTREET =0.016
Minor Storm Major Storm
Max. Allowable Spread for Minor & Major Storm TMAX =12.0 27.0 ft
Max. Allowable Depth at Gutter Flowline for Minor & Major Storm dMAX =6.0 9.2 inches
Allow Flow Depth at Street Crown (check box for yes, leave blank for no)
MINOR STORM Allowable Capacity is based on Spread Criterion Minor Storm Major Storm
MAJOR STORM Allowable Capacity is based on Spread Criterion Qallow =6.7 51.8 cfs
Minor storm max. allowable capacity GOOD - greater than the design peak flow of 0.44 cfs on sheet 'Inlet Management'
MHFD-Inlet, Version 5.03 (August 2023)
ALLOWABLE CAPACITY FOR ONE-HALF OF STREET (Minor & Major Storm)
(Based on Regulated Criteria for Maximum Allowable Flow Depth and Spread)
3979303 MHFD-Inlet_v5.03.xlsm, Inlet DP 8a 12/5/2024, 10:13 AM
Design Information (Input)MINOR MAJOR
Type of Inlet Type =
Local Depression (additional to continuous gutter depression 'a')aLOCAL =2.0 2.0 inches
Total Number of Units in the Inlet (Grate or Curb Opening)No =1 1
Length of a Single Unit Inlet (Grate or Curb Opening)Lo =3.00 3.00 ft
Width of a Unit Grate (cannot be greater than W, Gutter Width)Wo =1.73 1.73 ft
Clogging Factor for a Single Unit Grate (typical min. value = 0.5)Cf (G) =0.50 0.50
Clogging Factor for a Single Unit Curb Opening (typical min. value = 0.1)Cf (C) =0.10 0.10
Street Hydraulics: OK - Q < Allowable Street Capacity'MINOR MAJOR
Total Inlet Interception Capacity Q =0.4 1.3 cfs
Total Inlet Carry-Over Flow (flow bypassing inlet)Qb =0.0 0.7 cfs
Capture Percentage = Qa/Qo C% =95 67 %
INLET ON A CONTINUOUS GRADE
MHFD-Inlet, Version 5.03 (August 2023)
User-Defined CombinationUser-Defined Combination
3979303 MHFD-Inlet_v5.03.xlsm, Inlet DP 8a 12/5/2024, 10:13 AM
Project:
Inlet ID:
Gutter Geometry:
Maximum Allowable Width for Spread Behind Curb TBACK =13.5 ft
Side Slope Behind Curb (leave blank for no conveyance credit behind curb)SBACK =0.020 ft/ft
Manning's Roughness Behind Curb (typically between 0.012 and 0.020)nBACK =0.016
Height of Curb at Gutter Flow Line HCURB =6.00 inches
Distance from Curb Face to Street Crown TCROWN =27.0 ft
Gutter Width W =2.00 ft
Street Transverse Slope SX =0.020 ft/ft
Gutter Cross Slope (typically 2 inches over 24 inches or 0.083 ft/ft)SW =0.083 ft/ft
Street Longitudinal Slope - Enter 0 for sump condition SO =0.010 ft/ft
Manning's Roughness for Street Section (typically between 0.012 and 0.020)nSTREET =0.016
Minor Storm Major Storm
Max. Allowable Spread for Minor & Major Storm TMAX =12.0 27.0 ft
Max. Allowable Depth at Gutter Flowline for Minor & Major Storm dMAX =6.0 9.2 inches
Allow Flow Depth at Street Crown (check box for yes, leave blank for no)
MINOR STORM Allowable Capacity is based on Spread Criterion Minor Storm Major Storm
MAJOR STORM Allowable Capacity is based on Spread Criterion Qallow =4.7 36.6 cfs
Minor storm max. allowable capacity GOOD - greater than the design peak flow of 1.69 cfs on sheet 'Inlet Management'
MHFD-Inlet, Version 5.03 (August 2023)
ALLOWABLE CAPACITY FOR ONE-HALF OF STREET (Minor & Major Storm)
(Based on Regulated Criteria for Maximum Allowable Flow Depth and Spread)
3979303 MHFD-Inlet_v5.03.xlsm, Inlet DP 7a 12/5/2024, 10:13 AM
Design Information (Input)MINOR MAJOR
Type of Inlet Type =
Local Depression (additional to continuous gutter depression 'a')aLOCAL =2.0 2.0 inches
Total Number of Units in the Inlet (Grate or Curb Opening)No =4 4
Length of a Single Unit Inlet (Grate or Curb Opening)Lo =3.00 3.00 ft
Width of a Unit Grate (cannot be greater than W, Gutter Width)Wo =1.73 1.73 ft
Clogging Factor for a Single Unit Grate (typical min. value = 0.5)Cf (G) =0.50 0.50
Clogging Factor for a Single Unit Curb Opening (typical min. value = 0.1)Cf (C) =0.10 0.10
Street Hydraulics: OK - Q < Allowable Street Capacity'MINOR MAJOR
Total Inlet Interception Capacity Q =1.7 12.0 cfs
Total Inlet Carry-Over Flow (flow bypassing inlet)Qb =0.0 1.8 cfs
Capture Percentage = Qa/Qo C% =100 87 %
INLET ON A CONTINUOUS GRADE
MHFD-Inlet, Version 5.03 (August 2023)
User-Defined CombinationUser-Defined Combination
3979303 MHFD-Inlet_v5.03.xlsm, Inlet DP 7a 12/5/2024, 10:13 AM
Project:
Inlet ID:
Gutter Geometry:
Maximum Allowable Width for Spread Behind Curb TBACK =13.5 ft
Side Slope Behind Curb (leave blank for no conveyance credit behind curb)SBACK =0.020 ft/ft
Manning's Roughness Behind Curb (typically between 0.012 and 0.020)nBACK =0.016
Height of Curb at Gutter Flow Line HCURB =6.00 inches
Distance from Curb Face to Street Crown TCROWN =27.0 ft
Gutter Width W =2.00 ft
Street Transverse Slope SX =0.020 ft/ft
Gutter Cross Slope (typically 2 inches over 24 inches or 0.083 ft/ft)SW =0.083 ft/ft
Street Longitudinal Slope - Enter 0 for sump condition SO =0.010 ft/ft
Manning's Roughness for Street Section (typically between 0.012 and 0.020)nSTREET =0.016
Minor Storm Major Storm
Max. Allowable Spread for Minor & Major Storm TMAX =12.0 27.0 ft
Max. Allowable Depth at Gutter Flowline for Minor & Major Storm dMAX =6.0 9.2 inches
Allow Flow Depth at Street Crown (check box for yes, leave blank for no)
MINOR STORM Allowable Capacity is based on Spread Criterion Minor Storm Major Storm
MAJOR STORM Allowable Capacity is based on Spread Criterion Qallow =4.7 36.6 cfs
Minor storm max. allowable capacity GOOD - greater than the design peak flow of 0.26 cfs on sheet 'Inlet Management'
MHFD-Inlet, Version 5.03 (August 2023)
ALLOWABLE CAPACITY FOR ONE-HALF OF STREET (Minor & Major Storm)
(Based on Regulated Criteria for Maximum Allowable Flow Depth and Spread)
3979303 MHFD-Inlet_v5.03.xlsm, Inlet DP 9a 12/5/2024, 10:13 AM
Design Information (Input)MINOR MAJOR
Type of Inlet Type =
Local Depression (additional to continuous gutter depression 'a')aLOCAL =2.0 2.0 inches
Total Number of Units in the Inlet (Grate or Curb Opening)No =1 1
Length of a Single Unit Inlet (Grate or Curb Opening)Lo =3.00 3.00 ft
Width of a Unit Grate (cannot be greater than W, Gutter Width)Wo =1.73 1.73 ft
Clogging Factor for a Single Unit Grate (typical min. value = 0.5)Cf (G) =0.50 0.50
Clogging Factor for a Single Unit Curb Opening (typical min. value = 0.1)Cf (C) =0.10 0.10
Street Hydraulics: OK - Q < Allowable Street Capacity'MINOR MAJOR
Total Inlet Interception Capacity Q =0.3 0.9 cfs
Total Inlet Carry-Over Flow (flow bypassing inlet)Qb =0.0 0.2 cfs
Capture Percentage = Qa/Qo C% =100 81 %
INLET ON A CONTINUOUS GRADE
MHFD-Inlet, Version 5.03 (August 2023)
User-Defined CombinationUser-Defined Combination
3979303 MHFD-Inlet_v5.03.xlsm, Inlet DP 9a 12/5/2024, 10:13 AM
Project:
Inlet ID:
Gutter Geometry:
Maximum Allowable Width for Spread Behind Curb TBACK =13.5 ft
Side Slope Behind Curb (leave blank for no conveyance credit behind curb)SBACK =0.020 ft/ft
Manning's Roughness Behind Curb (typically between 0.012 and 0.020)nBACK =0.016
Height of Curb at Gutter Flow Line HCURB =6.00 inches
Distance from Curb Face to Street Crown TCROWN =18.0 ft
Gutter Width W =2.00 ft
Street Transverse Slope SX =0.020 ft/ft
Gutter Cross Slope (typically 2 inches over 24 inches or 0.083 ft/ft)SW =0.083 ft/ft
Street Longitudinal Slope - Enter 0 for sump condition SO =0.079 ft/ft
Manning's Roughness for Street Section (typically between 0.012 and 0.020)nSTREET =0.016
Minor Storm Major Storm
Max. Allowable Spread for Minor & Major Storm TMAX =6.0 18.0 ft
Max. Allowable Depth at Gutter Flowline for Minor & Major Storm dMAX =6.0 7.2 inches
Allow Flow Depth at Street Crown (check box for yes, leave blank for no)
MINOR STORM Allowable Capacity is based on Spread Criterion Minor Storm Major Storm
MAJOR STORM Allowable Capacity is based on Depth Criterion Qallow =3.3 19.5 cfs
Minor storm max. allowable capacity GOOD - greater than the design peak flow of 1.03 cfs on sheet 'Inlet Management'
MHFD-Inlet, Version 5.03 (August 2023)
ALLOWABLE CAPACITY FOR ONE-HALF OF STREET (Minor & Major Storm)
(Based on Regulated Criteria for Maximum Allowable Flow Depth and Spread)
3979303 MHFD-Inlet_v5.03.xlsm, Inlet DP 2c 12/5/2024, 10:13 AM
Design Information (Input)MINOR MAJOR
Type of Inlet Type =
Local Depression (additional to continuous gutter depression 'a')aLOCAL =2.0 2.0 inches
Total Number of Units in the Inlet (Grate or Curb Opening)No =4 4
Length of a Single Unit Inlet (Grate or Curb Opening)Lo =3.00 3.00 ft
Width of a Unit Grate (cannot be greater than W, Gutter Width)Wo =1.73 1.73 ft
Clogging Factor for a Single Unit Grate (typical min. value = 0.5)Cf (G) =0.50 0.50
Clogging Factor for a Single Unit Curb Opening (typical min. value = 0.1)Cf (C) =0.10 0.10
Street Hydraulics: OK - Q < Allowable Street Capacity'MINOR MAJOR
Total Inlet Interception Capacity Q =0.9 3.0 cfs
Total Inlet Carry-Over Flow (flow bypassing inlet)Qb =0.2 1.5 cfs
Capture Percentage = Qa/Qo C% =85 66 %
INLET ON A CONTINUOUS GRADE
MHFD-Inlet, Version 5.03 (August 2023)
User-Defined CombinationUser-Defined Combination
3979303 MHFD-Inlet_v5.03.xlsm, Inlet DP 2c 12/5/2024, 10:13 AM
Project:
Inlet ID:
Gutter Geometry:
Maximum Allowable Width for Spread Behind Curb TBACK =13.5 ft
Side Slope Behind Curb (leave blank for no conveyance credit behind curb)SBACK =0.020 ft/ft
Manning's Roughness Behind Curb (typically between 0.012 and 0.020)nBACK =0.016
Height of Curb at Gutter Flow Line HCURB =6.00 inches
Distance from Curb Face to Street Crown TCROWN =18.0 ft
Gutter Width W =2.00 ft
Street Transverse Slope SX =0.016 ft/ft
Gutter Cross Slope (typically 2 inches over 24 inches or 0.083 ft/ft)SW =0.083 ft/ft
Street Longitudinal Slope - Enter 0 for sump condition SO =0.025 ft/ft
Manning's Roughness for Street Section (typically between 0.012 and 0.020)nSTREET =0.016
Minor Storm Major Storm
Max. Allowable Spread for Minor & Major Storm TMAX =15.0 18.0 ft
Max. Allowable Depth at Gutter Flowline for Minor & Major Storm dMAX =6.0 8.0 inches
Allow Flow Depth at Street Crown (check box for yes, leave blank for no)
MINOR STORM Allowable Capacity is based on Spread Criterion Minor Storm Major Storm
MAJOR STORM Allowable Capacity is based on Depth Criterion Qallow =9.1 42.5 cfs
Minor storm max. allowable capacity GOOD - greater than the design peak flow of 4.56 cfs on sheet 'Inlet Management'
MHFD-Inlet, Version 5.03 (August 2023)
ALLOWABLE CAPACITY FOR ONE-HALF OF STREET (Minor & Major Storm)
(Based on Regulated Criteria for Maximum Allowable Flow Depth and Spread)
3979303 MHFD-Inlet_v5.03.xlsm, Inlet DP 1.1c 12/5/2024, 10:13 AM
Design Information (Input)MINOR MAJOR
Type of Inlet Type =
Local Depression (additional to continuous gutter depression 'a')aLOCAL =2.0 2.0 inches
Total Number of Units in the Inlet (Grate or Curb Opening)No =4 4
Length of a Single Unit Inlet (Grate or Curb Opening)Lo =3.00 3.00 ft
Width of a Unit Grate (cannot be greater than W, Gutter Width)Wo =1.73 1.73 ft
Clogging Factor for a Single Unit Grate (typical min. value = 0.5)Cf (G) =0.50 0.50
Clogging Factor for a Single Unit Curb Opening (typical min. value = 0.1)Cf (C) =0.10 0.10
Street Hydraulics: OK - Q < Allowable Street Capacity'MINOR MAJOR
Total Inlet Interception Capacity Q =4.0 13.2 cfs
Total Inlet Carry-Over Flow (flow bypassing inlet)Qb =0.6 8.9 cfs
Capture Percentage = Qa/Qo C% =88 60 %
INLET ON A CONTINUOUS GRADE
MHFD-Inlet, Version 5.03 (August 2023)
User-Defined CombinationUser-Defined Combination
3979303 MHFD-Inlet_v5.03.xlsm, Inlet DP 1.1c 12/5/2024, 10:13 AM
Project:
Inlet ID:
Gutter Geometry:
Maximum Allowable Width for Spread Behind Curb TBACK =13.0 ft
Side Slope Behind Curb (leave blank for no conveyance credit behind curb)SBACK =0.020 ft/ft
Manning's Roughness Behind Curb (typically between 0.012 and 0.020)nBACK =0.016
Height of Curb at Gutter Flow Line HCURB =6.00 inches
Distance from Curb Face to Street Crown TCROWN =27.0 ft
Gutter Width W =2.00 ft
Street Transverse Slope SX =0.020 ft/ft
Gutter Cross Slope (typically 2 inches over 24 inches or 0.083 ft/ft)SW =0.083 ft/ft
Street Longitudinal Slope - Enter 0 for sump condition SO =0.020 ft/ft
Manning's Roughness for Street Section (typically between 0.012 and 0.020)nSTREET =0.016
Minor Storm Major Storm
Max. Allowable Spread for Minor & Major Storm TMAX =12.0 27.0 ft
Max. Allowable Depth at Gutter Flowline for Minor & Major Storm dMAX =6.0 12.0 inches
Allow Flow Depth at Street Crown (check box for yes, leave blank for no)
MINOR STORM Allowable Capacity is based on Spread Criterion Minor Storm Major Storm
MAJOR STORM Allowable Capacity is based on Spread Criterion Qallow =6.7 51.8 cfs
Minor storm max. allowable capacity GOOD - greater than the design peak flow of 1.58 cfs on sheet 'Inlet Management'
MHFD-Inlet, Version 5.03 (August 2023)
ALLOWABLE CAPACITY FOR ONE-HALF OF STREET (Minor & Major Storm)
(Based on Regulated Criteria for Maximum Allowable Flow Depth and Spread)
3979303 MHFD-Inlet_v5.03.xlsm, Inlet DP 4.1c 12/5/2024, 10:13 AM
Design Information (Input)MINOR MAJOR
Type of Inlet Type =
Local Depression (additional to continuous gutter depression 'a')aLOCAL =2.0 2.0 inches
Total Number of Units in the Inlet (Grate or Curb Opening)No =4 4
Length of a Single Unit Inlet (Grate or Curb Opening)Lo =3.00 3.00 ft
Width of a Unit Grate (cannot be greater than W, Gutter Width)Wo =1.73 1.73 ft
Clogging Factor for a Single Unit Grate (typical min. value = 0.5)Cf (G) =0.50 0.50
Clogging Factor for a Single Unit Curb Opening (typical min. value = 0.1)Cf (C) =0.10 0.10
Street Hydraulics: OK - Q < Allowable Street Capacity'MINOR MAJOR
Total Inlet Interception Capacity Q =1.6 15.0 cfs
Total Inlet Carry-Over Flow (flow bypassing inlet)Qb =0.0 7.2 cfs
Capture Percentage = Qa/Qo C% =100 68 %
INLET ON A CONTINUOUS GRADE
MHFD-Inlet, Version 5.03 (August 2023)
User-Defined CombinationUser-Defined Combination
3979303 MHFD-Inlet_v5.03.xlsm, Inlet DP 4.1c 12/5/2024, 10:13 AM
Project:
Inlet ID:
Gutter Geometry:
Maximum Allowable Width for Spread Behind Curb TBACK =13.5 ft
Side Slope Behind Curb (leave blank for no conveyance credit behind curb)SBACK =0.020 ft/ft
Manning's Roughness Behind Curb (typically between 0.012 and 0.020)nBACK =0.016
Height of Curb at Gutter Flow Line HCURB =6.00 inches
Distance from Curb Face to Street Crown TCROWN =27.0 ft
Gutter Width W =2.00 ft
Street Transverse Slope SX =0.020 ft/ft
Gutter Cross Slope (typically 2 inches over 24 inches or 0.083 ft/ft)SW =0.083 ft/ft
Street Longitudinal Slope - Enter 0 for sump condition SO =0.000 ft/ft
Manning's Roughness for Street Section (typically between 0.012 and 0.020)nSTREET =0.016
Minor Storm Major Storm
Max. Allowable Spread for Minor & Major Storm TMAX =12.0 27.0 ft
Max. Allowable Depth at Gutter Flowline for Minor & Major Storm dMAX =6.0 9.0 inches
Check boxes are not applicable in SUMP conditions
MINOR STORM Allowable Capacity is not applicable to Sump Condition Minor Storm Major Storm
MAJOR STORM Allowable Capacity is not applicable to Sump Condition Qallow =SUMP SUMP cfs
MHFD-Inlet, Version 5.03 (August 2023)
ALLOWABLE CAPACITY FOR ONE-HALF OF STREET (Minor & Major Storm)
(Based on Regulated Criteria for Maximum Allowable Flow Depth and Spread)
3979303 MHFD-Inlet_v5.03.xlsm, Inlet DP 4.2c 12/5/2024, 10:13 AM
Design Information (Input)MINOR MAJOR
Type of Inlet Type =
Local Depression (additional to continuous gutter depression 'a' from above)alocal =3.00 3.00 inches
Number of Unit Inlets (Grate or Curb Opening)No =3 3
Water Depth at Flowline (outside of local depression)Ponding Depth =6.0 8.1 inches
Grate Information MINOR MAJOR
Length of a Unit Grate Lo (G) =N/A N/A feet
Width of a Unit Grate Wo =N/A N/A feet
Open Area Ratio for a Grate (typical values 0.15-0.90)Aratio =N/A N/A
Clogging Factor for a Single Grate (typical value 0.50 - 0.70)Cf (G) =N/A N/A
Grate Weir Coefficient (typical value 2.15 - 3.60)Cw (G) =N/A N/A
Grate Orifice Coefficient (typical value 0.60 - 0.80)Co (G) =N/A N/A
Curb Opening Information MINOR MAJOR
Length of a Unit Curb Opening Lo (C) =5.00 5.00 feet
Height of Vertical Curb Opening in Inches Hvert =6.00 6.00 inches
Height of Curb Orifice Throat in Inches Hthroat =6.00 6.00 inches
Angle of Throat Theta =63.40 63.40 degrees
Side Width for Depression Pan (typically the gutter width of 2 feet)Wp =2.00 2.00 feet
Clogging Factor for a Single Curb Opening (typical value 0.10)Cf (C) =0.10 0.10
Curb Opening Weir Coefficient (typical value 2.3-3.7)Cw (C) =3.60 3.60
Curb Opening Orifice Coefficient (typical value 0.60 - 0.70)Co (C) =0.67 0.67
Low Head Performance Reduction (Calculated)MINOR MAJOR
Depth for Grate Midwidth d =N/A N/A ft
Depth for Curb Opening Weir Equation d =0.33 0.51 ft
Grated Inlet Performance Reduction Factor for Long Inlets RF =N/A N/A
Curb Opening Performance Reduction Factor for Long Inlets RF =0.79 0.90
Combination Inlet Performance Reduction Factor for Long Inlets RF =N/A N/A
MINOR MAJOR
Total Inlet Interception Capacity (assumes clogged condition)Qa =9.7 20.9 cfs
Inlet Capacity IS GOOD for Minor and Major Storms (>Q Peak)Q PEAK REQUIRED =2.8 20.0 cfs
CDOT Type R Curb Opening
INLET IN A SUMP OR SAG LOCATION
MHFD-Inlet, Version 5.03 (August 2023)
H-VertH-Curb
W
Lo (C)
Lo (G)
Wo
WP
CDOT Type R Curb Opening
Override Depths
3979303 MHFD-Inlet_v5.03.xlsm, Inlet DP 4.2c 12/5/2024, 10:13 AM
Project:
Inlet ID:
Gutter Geometry:
Maximum Allowable Width for Spread Behind Curb TBACK =13.5 ft
Side Slope Behind Curb (leave blank for no conveyance credit behind curb)SBACK =0.020 ft/ft
Manning's Roughness Behind Curb (typically between 0.012 and 0.020)nBACK =0.016
Height of Curb at Gutter Flow Line HCURB =6.00 inches
Distance from Curb Face to Street Crown TCROWN =27.0 ft
Gutter Width W =2.00 ft
Street Transverse Slope SX =0.020 ft/ft
Gutter Cross Slope (typically 2 inches over 24 inches or 0.083 ft/ft)SW =0.083 ft/ft
Street Longitudinal Slope - Enter 0 for sump condition SO =0.000 ft/ft
Manning's Roughness for Street Section (typically between 0.012 and 0.020)nSTREET =0.016
Minor Storm Major Storm
Max. Allowable Spread for Minor & Major Storm TMAX =12.0 27.0 ft
Max. Allowable Depth at Gutter Flowline for Minor & Major Storm dMAX =6.0 9.0 inches
Check boxes are not applicable in SUMP conditions
MINOR STORM Allowable Capacity is not applicable to Sump Condition Minor Storm Major Storm
MAJOR STORM Allowable Capacity is not applicable to Sump Condition Qallow =SUMP SUMP cfs
MHFD-Inlet, Version 5.03 (August 2023)
ALLOWABLE CAPACITY FOR ONE-HALF OF STREET (Minor & Major Storm)
(Based on Regulated Criteria for Maximum Allowable Flow Depth and Spread)
3979303 MHFD-Inlet_v5.03.xlsm, Inlet DP 5c 12/5/2024, 10:13 AM
Design Information (Input)MINOR MAJOR
Type of Inlet Type =
Local Depression (additional to continuous gutter depression 'a' from above)alocal =3.00 3.00 inches
Number of Unit Inlets (Grate or Curb Opening)No =1 1
Water Depth at Flowline (outside of local depression)Ponding Depth =4.4 8.0 inches
Grate Information MINOR MAJOR
Length of a Unit Grate Lo (G) =N/A N/A feet
Width of a Unit Grate Wo =N/A N/A feet
Open Area Ratio for a Grate (typical values 0.15-0.90)Aratio =N/A N/A
Clogging Factor for a Single Grate (typical value 0.50 - 0.70)Cf (G) =N/A N/A
Grate Weir Coefficient (typical value 2.15 - 3.60)Cw (G) =N/A N/A
Grate Orifice Coefficient (typical value 0.60 - 0.80)Co (G) =N/A N/A
Curb Opening Information MINOR MAJOR
Length of a Unit Curb Opening Lo (C) =15.00 15.00 feet
Height of Vertical Curb Opening in Inches Hvert =6.00 6.00 inches
Height of Curb Orifice Throat in Inches Hthroat =6.00 6.00 inches
Angle of Throat Theta =63.40 63.40 degrees
Side Width for Depression Pan (typically the gutter width of 2 feet)Wp =2.00 2.00 feet
Clogging Factor for a Single Curb Opening (typical value 0.10)Cf (C) =0.10 0.10
Curb Opening Weir Coefficient (typical value 2.3-3.7)Cw (C) =3.60 3.60
Curb Opening Orifice Coefficient (typical value 0.60 - 0.70)Co (C) =0.67 0.67
Low Head Performance Reduction (Calculated)MINOR MAJOR
Depth for Grate Midwidth d =N/A N/A ft
Depth for Curb Opening Weir Equation d =0.20 0.50 ft
Grated Inlet Performance Reduction Factor for Long Inlets RF =N/A N/A
Curb Opening Performance Reduction Factor for Long Inlets RF =0.67 0.89
Combination Inlet Performance Reduction Factor for Long Inlets RF =N/A N/A
MINOR MAJOR
Total Inlet Interception Capacity (assumes clogged condition)Qa =3.8 20.2 cfs
Inlet Capacity IS GOOD for Minor and Major Storms (>Q Peak)Q PEAK REQUIRED =1.8 8.1 cfs
CDOT Type R Curb Opening
INLET IN A SUMP OR SAG LOCATION
MHFD-Inlet, Version 5.03 (August 2023)
H-VertH-Curb
W
Lo (C)
Lo (G)
Wo
WP
CDOT Type R Curb Opening
Override Depths
3979303 MHFD-Inlet_v5.03.xlsm, Inlet DP 5c 12/5/2024, 10:13 AM
Project:
Inlet ID:
Gutter Geometry:
Maximum Allowable Width for Spread Behind Curb TBACK =13.5 ft
Side Slope Behind Curb (leave blank for no conveyance credit behind curb)SBACK =0.020 ft/ft
Manning's Roughness Behind Curb (typically between 0.012 and 0.020)nBACK =0.016
Height of Curb at Gutter Flow Line HCURB =6.00 inches
Distance from Curb Face to Street Crown TCROWN =18.0 ft
Gutter Width W =2.00 ft
Street Transverse Slope SX =0.020 ft/ft
Gutter Cross Slope (typically 2 inches over 24 inches or 0.083 ft/ft)SW =0.083 ft/ft
Street Longitudinal Slope - Enter 0 for sump condition SO =0.000 ft/ft
Manning's Roughness for Street Section (typically between 0.012 and 0.020)nSTREET =0.016
Minor Storm Major Storm
Max. Allowable Spread for Minor & Major Storm TMAX =9.0 18.0 ft
Max. Allowable Depth at Gutter Flowline for Minor & Major Storm dMAX =5.0 6.1 inches
Check boxes are not applicable in SUMP conditions
MINOR STORM Allowable Capacity is not applicable to Sump Condition Minor Storm Major Storm
MAJOR STORM Allowable Capacity is not applicable to Sump Condition Qallow =SUMP SUMP cfs
MHFD-Inlet, Version 5.03 (August 2023)
ALLOWABLE CAPACITY FOR ONE-HALF OF STREET (Minor & Major Storm)
(Based on Regulated Criteria for Maximum Allowable Flow Depth and Spread)
3979303 MHFD-Inlet_v5.03.xlsm, Inlet DP 1d 12/5/2024, 10:13 AM
Design Information (Input)MINOR MAJOR
Type of Inlet Type =
Local Depression (additional to continuous gutter depression 'a' from above)alocal =3.00 3.00 inches
Number of Unit Inlets (Grate or Curb Opening)No =1 1
Water Depth at Flowline (outside of local depression)Ponding Depth =3.7 5.8 inches
Grate Information MINOR MAJOR
Length of a Unit Grate Lo (G) =N/A N/A feet
Width of a Unit Grate Wo =N/A N/A feet
Open Area Ratio for a Grate (typical values 0.15-0.90)Aratio =N/A N/A
Clogging Factor for a Single Grate (typical value 0.50 - 0.70)Cf (G) =N/A N/A
Grate Weir Coefficient (typical value 2.15 - 3.60)Cw (G) =N/A N/A
Grate Orifice Coefficient (typical value 0.60 - 0.80)Co (G) =N/A N/A
Curb Opening Information MINOR MAJOR
Length of a Unit Curb Opening Lo (C) =10.00 10.00 feet
Height of Vertical Curb Opening in Inches Hvert =6.00 6.00 inches
Height of Curb Orifice Throat in Inches Hthroat =6.00 6.00 inches
Angle of Throat Theta =63.40 63.40 degrees
Side Width for Depression Pan (typically the gutter width of 2 feet)Wp =2.00 2.00 feet
Clogging Factor for a Single Curb Opening (typical value 0.10)Cf (C) =0.10 0.10
Curb Opening Weir Coefficient (typical value 2.3-3.7)Cw (C) =3.60 3.60
Curb Opening Orifice Coefficient (typical value 0.60 - 0.70)Co (C) =0.67 0.67
Low Head Performance Reduction (Calculated)MINOR MAJOR
Depth for Grate Midwidth d =N/A N/A ft
Depth for Curb Opening Weir Equation d =0.14 0.32 ft
Grated Inlet Performance Reduction Factor for Long Inlets RF =N/A N/A
Curb Opening Performance Reduction Factor for Long Inlets RF =0.76 0.92
Combination Inlet Performance Reduction Factor for Long Inlets RF =N/A N/A
MINOR MAJOR
Total Inlet Interception Capacity (assumes clogged condition)Qa =1.8 7.7 cfs
Inlet Capacity IS GOOD for Minor and Major Storms (>Q Peak)Q PEAK REQUIRED =0.5 2.8 cfs
INLET IN A SUMP OR SAG LOCATION
MHFD-Inlet, Version 5.03 (August 2023)
CDOT Type R Curb Opening
H-VertH-Curb
W
Lo (C)
Lo (G)
Wo
WP
CDOT Type R Curb Opening
Override Depths
3979303 MHFD-Inlet_v5.03.xlsm, Inlet DP 1d 12/5/2024, 10:13 AM
Project:
Inlet ID:
Gutter Geometry:
Maximum Allowable Width for Spread Behind Curb TBACK =13.5 ft
Side Slope Behind Curb (leave blank for no conveyance credit behind curb)SBACK =0.020 ft/ft
Manning's Roughness Behind Curb (typically between 0.012 and 0.020)nBACK =0.016
Height of Curb at Gutter Flow Line HCURB =6.00 inches
Distance from Curb Face to Street Crown TCROWN =18.0 ft
Gutter Width W =2.00 ft
Street Transverse Slope SX =0.020 ft/ft
Gutter Cross Slope (typically 2 inches over 24 inches or 0.083 ft/ft)SW =0.083 ft/ft
Street Longitudinal Slope - Enter 0 for sump condition SO =0.000 ft/ft
Manning's Roughness for Street Section (typically between 0.012 and 0.020)nSTREET =0.016
Minor Storm Major Storm
Max. Allowable Spread for Minor & Major Storm TMAX =9.0 18.0 ft
Max. Allowable Depth at Gutter Flowline for Minor & Major Storm dMAX =5.0 6.1 inches
Check boxes are not applicable in SUMP conditions
MINOR STORM Allowable Capacity is not applicable to Sump Condition Minor Storm Major Storm
MAJOR STORM Allowable Capacity is not applicable to Sump Condition Qallow =SUMP SUMP cfs
MHFD-Inlet, Version 5.03 (August 2023)
ALLOWABLE CAPACITY FOR ONE-HALF OF STREET (Minor & Major Storm)
(Based on Regulated Criteria for Maximum Allowable Flow Depth and Spread)
3979303 MHFD-Inlet_v5.03.xlsm, Inlet DP 2d 12/5/2024, 10:13 AM
Design Information (Input)MINOR MAJOR
Type of Inlet Type =
Local Depression (additional to continuous gutter depression 'a' from above)alocal =3.00 3.00 inches
Number of Unit Inlets (Grate or Curb Opening)No =1 1
Water Depth at Flowline (outside of local depression)Ponding Depth =3.7 5.8 inches
Grate Information MINOR MAJOR
Length of a Unit Grate Lo (G) =N/A N/A feet
Width of a Unit Grate Wo =N/A N/A feet
Open Area Ratio for a Grate (typical values 0.15-0.90)Aratio =N/A N/A
Clogging Factor for a Single Grate (typical value 0.50 - 0.70)Cf (G) =N/A N/A
Grate Weir Coefficient (typical value 2.15 - 3.60)Cw (G) =N/A N/A
Grate Orifice Coefficient (typical value 0.60 - 0.80)Co (G) =N/A N/A
Curb Opening Information MINOR MAJOR
Length of a Unit Curb Opening Lo (C) =5.00 5.00 feet
Height of Vertical Curb Opening in Inches Hvert =6.00 6.00 inches
Height of Curb Orifice Throat in Inches Hthroat =6.00 6.00 inches
Angle of Throat Theta =63.40 63.40 degrees
Side Width for Depression Pan (typically the gutter width of 2 feet)Wp =2.00 2.00 feet
Clogging Factor for a Single Curb Opening (typical value 0.10)Cf (C) =0.10 0.10
Curb Opening Weir Coefficient (typical value 2.3-3.7)Cw (C) =3.60 3.60
Curb Opening Orifice Coefficient (typical value 0.60 - 0.70)Co (C) =0.67 0.67
Low Head Performance Reduction (Calculated)MINOR MAJOR
Depth for Grate Midwidth d =N/A N/A ft
Depth for Curb Opening Weir Equation d =0.14 0.32 ft
Grated Inlet Performance Reduction Factor for Long Inlets RF =N/A N/A
Curb Opening Performance Reduction Factor for Long Inlets RF =1.00 1.00
Combination Inlet Performance Reduction Factor for Long Inlets RF =N/A N/A
MINOR MAJOR
Total Inlet Interception Capacity (assumes clogged condition)Qa =1.5 5.0 cfs
Inlet Capacity IS GOOD for Minor and Major Storms (>Q Peak)Q PEAK REQUIRED =0.7 4.4 cfs
INLET IN A SUMP OR SAG LOCATION
MHFD-Inlet, Version 5.03 (August 2023)
CDOT Type R Curb Opening
H-VertH-Curb
W
Lo (C)
Lo (G)
Wo
WP
CDOT Type R Curb Opening
Override Depths
3979303 MHFD-Inlet_v5.03.xlsm, Inlet DP 2d 12/5/2024, 10:13 AM
Project:
Inlet ID:
Gutter Geometry:
Maximum Allowable Width for Spread Behind Curb TBACK =11.0 ft
Side Slope Behind Curb (leave blank for no conveyance credit behind curb)SBACK =0.020 ft/ft
Manning's Roughness Behind Curb (typically between 0.012 and 0.020)nBACK =0.016
Height of Curb at Gutter Flow Line HCURB =6.00 inches
Distance from Curb Face to Street Crown TCROWN =87.9 ft
Gutter Width W =1.73 ft
Street Transverse Slope SX =0.006 ft/ft
Gutter Cross Slope (typically 2 inches over 24 inches or 0.083 ft/ft)SW =0.083 ft/ft
Street Longitudinal Slope - Enter 0 for sump condition SO =0.000 ft/ft
Manning's Roughness for Street Section (typically between 0.012 and 0.020)nSTREET =0.016
Minor Storm Major Storm
Max. Allowable Spread for Minor & Major Storm TMAX =20.0 87.9 ft
Max. Allowable Depth at Gutter Flowline for Minor & Major Storm dMAX =4.0 6.0 inches
Check boxes are not applicable in SUMP conditions
MINOR STORM Allowable Capacity is not applicable to Sump Condition Minor Storm Major Storm
MAJOR STORM Allowable Capacity is not applicable to Sump Condition Qallow =SUMP SUMP cfs
MHFD-Inlet, Version 5.03 (August 2023)
ALLOWABLE CAPACITY FOR ONE-HALF OF STREET (Minor & Major Storm)
(Based on Regulated Criteria for Maximum Allowable Flow Depth and Spread)
3979303 MHFD-Inlet_v5.03.xlsm, Inlet DP 3e 12/5/2024, 10:13 AM
Design Information (Input)MINOR MAJOR
Type of Inlet Type =
Local Depression (additional to continuous gutter depression 'a' from above)alocal =2.00 2.00 inches
Number of Unit Inlets (Grate or Curb Opening)No =1 1
Water Depth at Flowline (outside of local depression)Ponding Depth =3.0 6.0 inches
Grate Information MINOR MAJOR
Length of a Unit Grate Lo (G) =3.00 3.00 feet
Width of a Unit Grate Wo =1.73 1.73 feet
Open Area Ratio for a Grate (typical values 0.15-0.90)Aratio =0.43 0.43
Clogging Factor for a Single Grate (typical value 0.50 - 0.70)Cf (G) =0.50 0.50
Grate Weir Coefficient (typical value 2.15 - 3.60)Cw (G) =3.30 3.30
Grate Orifice Coefficient (typical value 0.60 - 0.80)Co (G) =0.60 0.60
Curb Opening Information MINOR MAJOR
Length of a Unit Curb Opening Lo (C) =3.00 3.00 feet
Height of Vertical Curb Opening in Inches Hvert =6.50 6.50 inches
Height of Curb Orifice Throat in Inches Hthroat =5.25 5.25 inches
Angle of Throat Theta =0.00 0.00 degrees
Side Width for Depression Pan (typically the gutter width of 2 feet)Wp =1.73 1.73 feet
Clogging Factor for a Single Curb Opening (typical value 0.10)Cf (C) =0.10 0.10
Curb Opening Weir Coefficient (typical value 2.3-3.7)Cw (C) =3.70 3.70
Curb Opening Orifice Coefficient (typical value 0.60 - 0.70)Co (C) =0.66 0.66
Low Head Performance Reduction (Calculated)MINOR MAJOR
Depth for Grate Midwidth d =0.26 0.51 ft
Depth for Curb Opening Weir Equation d =0.11 0.36 ft
Grated Inlet Performance Reduction Factor for Long Inlets RF =0.47 0.94
Curb Opening Performance Reduction Factor for Long Inlets RF =N/A N/A
Combination Inlet Performance Reduction Factor for Long Inlets RF =0.47 0.94
MINOR MAJOR
Total Inlet Interception Capacity (assumes clogged condition)Qa =0.8 6.2 cfs
Inlet Capacity IS GOOD for Minor and Major Storms (>Q Peak)Q PEAK REQUIRED =0.4 1.9 cfs
INLET IN A SUMP OR SAG LOCATION
MHFD-Inlet, Version 5.03 (August 2023)
User-Defined Combination
H-VertH-Curb
W
Lo (C)
Lo (G)
Wo
WP
User-Defined Combination
Override Depths
3979303 MHFD-Inlet_v5.03.xlsm, Inlet DP 3e 12/5/2024, 10:13 AM
Project:
Inlet ID:
Gutter Geometry:
Maximum Allowable Width for Spread Behind Curb TBACK =13.0 ft
Side Slope Behind Curb (leave blank for no conveyance credit behind curb)SBACK =0.020 ft/ft
Manning's Roughness Behind Curb (typically between 0.012 and 0.020)nBACK =0.016
Height of Curb at Gutter Flow Line HCURB =6.00 inches
Distance from Curb Face to Street Crown TCROWN =18.0 ft
Gutter Width W =2.00 ft
Street Transverse Slope SX =0.020 ft/ft
Gutter Cross Slope (typically 2 inches over 24 inches or 0.083 ft/ft)SW =0.083 ft/ft
Street Longitudinal Slope - Enter 0 for sump condition SO =0.000 ft/ft
Manning's Roughness for Street Section (typically between 0.012 and 0.020)nSTREET =0.016
Minor Storm Major Storm
Max. Allowable Spread for Minor & Major Storm TMAX =9.0 18.0 ft
Max. Allowable Depth at Gutter Flowline for Minor & Major Storm dMAX =4.0 7.2 inches
Check boxes are not applicable in SUMP conditions
MINOR STORM Allowable Capacity is not applicable to Sump Condition Minor Storm Major Storm
MAJOR STORM Allowable Capacity is not applicable to Sump Condition Qallow =SUMP SUMP cfs
MHFD-Inlet, Version 5.03 (August 2023)
ALLOWABLE CAPACITY FOR ONE-HALF OF STREET (Minor & Major Storm)
(Based on Regulated Criteria for Maximum Allowable Flow Depth and Spread)
3979303 MHFD-Inlet_v5.03.xlsm, Inlet DP 2e 12/5/2024, 10:13 AM
Design Information (Input)MINOR MAJOR
Type of Inlet Type =
Local Depression (additional to continuous gutter depression 'a' from above)alocal =3.00 3.00 inches
Number of Unit Inlets (Grate or Curb Opening)No =1 1
Water Depth at Flowline (outside of local depression)Ponding Depth =3.7 5.8 inches
Grate Information MINOR MAJOR
Length of a Unit Grate Lo (G) =N/A N/A feet
Width of a Unit Grate Wo =N/A N/A feet
Open Area Ratio for a Grate (typical values 0.15-0.90)Aratio =N/A N/A
Clogging Factor for a Single Grate (typical value 0.50 - 0.70)Cf (G) =N/A N/A
Grate Weir Coefficient (typical value 2.15 - 3.60)Cw (G) =N/A N/A
Grate Orifice Coefficient (typical value 0.60 - 0.80)Co (G) =N/A N/A
Curb Opening Information MINOR MAJOR
Length of a Unit Curb Opening Lo (C) =5.00 5.00 feet
Height of Vertical Curb Opening in Inches Hvert =6.00 6.00 inches
Height of Curb Orifice Throat in Inches Hthroat =6.00 6.00 inches
Angle of Throat Theta =63.40 63.40 degrees
Side Width for Depression Pan (typically the gutter width of 2 feet)Wp =2.00 2.00 feet
Clogging Factor for a Single Curb Opening (typical value 0.10)Cf (C) =0.10 0.10
Curb Opening Weir Coefficient (typical value 2.3-3.7)Cw (C) =3.60 3.60
Curb Opening Orifice Coefficient (typical value 0.60 - 0.70)Co (C) =0.67 0.67
Low Head Performance Reduction (Calculated)MINOR MAJOR
Depth for Grate Midwidth d =N/A N/A ft
Depth for Curb Opening Weir Equation d =0.14 0.32 ft
Grated Inlet Performance Reduction Factor for Long Inlets RF =N/A N/A
Curb Opening Performance Reduction Factor for Long Inlets RF =1.00 1.00
Combination Inlet Performance Reduction Factor for Long Inlets RF =N/A N/A
MINOR MAJOR
Total Inlet Interception Capacity (assumes clogged condition)Qa =1.5 5.0 cfs
WARNING: Inlet Capacity < Q Peak for Minor and Major Storms Q PEAK REQUIRED =1.8 7.9 cfs
INLET IN A SUMP OR SAG LOCATION
MHFD-Inlet, Version 5.03 (August 2023)
CDOT Type R Curb Opening
H-VertH-Curb
W
Lo (C)
Lo (G)
Wo
WP
CDOT Type R Curb Opening
Override Depths
3979303 MHFD-Inlet_v5.03.xlsm, Inlet DP 2e 12/5/2024, 10:13 AM
Project:
Inlet ID:
Gutter Geometry:
Maximum Allowable Width for Spread Behind Curb TBACK =12.0 ft
Side Slope Behind Curb (leave blank for no conveyance credit behind curb)SBACK =0.020 ft/ft
Manning's Roughness Behind Curb (typically between 0.012 and 0.020)nBACK =0.012
Height of Curb at Gutter Flow Line HCURB =6.00 inches
Distance from Curb Face to Street Crown TCROWN =32.0 ft
Gutter Width W =2.00 ft
Street Transverse Slope SX =0.020 ft/ft
Gutter Cross Slope (typically 2 inches over 24 inches or 0.083 ft/ft)SW =0.083 ft/ft
Street Longitudinal Slope - Enter 0 for sump condition SO =0.014 ft/ft
Manning's Roughness for Street Section (typically between 0.012 and 0.020)nSTREET =0.016
Minor Storm Major Storm
Max. Allowable Spread for Minor & Major Storm TMAX =15.0 25.0 ft
Max. Allowable Depth at Gutter Flowline for Minor & Major Storm dMAX =4.0 6.8 inches
Allow Flow Depth at Street Crown (check box for yes, leave blank for no)
MINOR STORM Allowable Capacity is based on Depth Criterion Minor Storm Major Storm
MAJOR STORM Allowable Capacity is based on Depth Criterion Qallow =4.0 24.9 cfs
Minor storm max. allowable capacity GOOD - greater than the design peak flow of 3.00 cfs on sheet 'Inlet Management'
MHFD-Inlet, Version 5.03 (August 2023)
ALLOWABLE CAPACITY FOR ONE-HALF OF STREET (Minor & Major Storm)
(Based on Regulated Criteria for Maximum Allowable Flow Depth and Spread)
3979303 MHFD-Inlet_v5.03.xlsm, Inlet DP J910B 12/5/2024, 10:13 AM
Design Information (Input)MINOR MAJOR
Type of Inlet Type =
Local Depression (additional to continuous gutter depression 'a')aLOCAL =3.0 3.0 inches
Total Number of Units in the Inlet (Grate or Curb Opening)No =5 5 Modeled as 10' ex typ R and a 15'
Length of a Single Unit Inlet (Grate or Curb Opening)Lo =5.00 5.00 ft Proposed Type R inlet
Width of a Unit Grate (cannot be greater than W, Gutter Width)Wo =N/A N/A ft
Clogging Factor for a Single Unit Grate (typical min. value = 0.5)Cf (G) =N/A N/A
Clogging Factor for a Single Unit Curb Opening (typical min. value = 0.1)Cf (C) =0.10 0.10
Street Hydraulics: OK - Q < Allowable Street Capacity'MINOR MAJOR
Total Inlet Interception Capacity Q =3.0 20.2 cfs
Total Inlet Carry-Over Flow (flow bypassing inlet)Qb =0.0 1.8 cfs
Capture Percentage = Qa/Qo C% =100 92 %
INLET ON A CONTINUOUS GRADE
MHFD-Inlet, Version 5.03 (August 2023)
CDOT Type R Curb OpeningCDOT Type R Curb Opening
One type ex 10' type R and
one 15' type R
3979303 MHFD-Inlet_v5.03.xlsm, Inlet DP J910B 12/5/2024, 10:13 AM
Flow Rate (Q)Ponding Depth 4" (y)Ponding Depth 6" (y)Ponding Depth 9" (y)Ponding Depth 12" (y)Ponding Depth 18" (y)
0.0 0.00 0.00 0.00 0.00 0.00
1.0 0.79 0.16 0.11 0.13 0.13
2.0 2.22 0.45 0.24 0.24 0.23
3.0 4.06 0.81 0.37 0.35 0.33
4.0 6.23 1.24 0.51 0.45 0.42
5.0 8.69 1.73 0.65 0.55 0.51
6.0 11.40 2.27 0.79 0.65 0.60
7.0 14.35 2.85 0.94 0.75 0.68
8.0 17.51 3.47 1.08 0.84 0.76
9.0 20.87 4.13 1.23 0.94 0.84
9.2 21.56 4.27 1.26 0.96 0.86
10.0 24.41 4.83 1.38 1.03 0.92
11.0 28.14 5.56 1.54 1.13 1.00
12.0 32.03 6.33 1.69 1.22 1.07
13.0 36.09 7.12 1.85 1.31 1.15
14.0 40.30 7.95 2.01 1.40 1.23
y = Number of inlets
DP 2 Year Flow -cfs 100 Year Flow - cfs
4g
Inches
Ponding Depth 9 Inches
No. Inlet 100 Year Req to capture 100%3.0
No. of Inlets Provided 5.0
No Bypass Flow 0 cfs
Number of CDOT Type 13 Inlets required for given Capacity at a Sump
Flow Rate (Q)Ponding Depth 4" (y)Ponding Depth 6" (y)Ponding Depth 9" (y)Ponding Depth 12" (y)Ponding Depth 18" (y)
0.0 0.00 0.00 0.00 0.00 0.00
1.0 0.79 0.16 0.11 0.13 0.13
2.0 2.22 0.45 0.24 0.24 0.23
3.0 4.06 0.81 0.37 0.35 0.33
4.0 6.23 1.24 0.51 0.45 0.42
5.0 8.69 1.73 0.65 0.55 0.51
6.0 11.40 2.27 0.79 0.65 0.60
7.0 14.35 2.85 0.94 0.75 0.68
8.0 17.51 3.47 1.08 0.84 0.76
9.0 20.87 4.13 1.23 0.94 0.84
9.2 21.56 4.27 1.26 0.96 0.86
10.0 24.41 4.83 1.38 1.03 0.92
11.0 28.14 5.56 1.54 1.13 1.00
12.0 32.03 6.33 1.69 1.22 1.07
13.0 36.09 7.12 1.85 1.31 1.15
14.0 40.30 7.95 2.01 1.40 1.23
15.0 44.67 8.81 2.16 1.49 1.30
y = Number of inlets
DP 2 Year Flow -cfs 100 Year Flow - cfs
1b 1.26 6.27
Ponding Depth 6 Inches
No. Inlet 100 Year Req to capture 100%3.0
Inlets Provided 3.0
Number of CDOT Type 13 Inlets required for given Capacity at a Sump
Flow Rate (Q)Ponding Depth 4" (y)Ponding Depth 6" (y)Ponding Depth 9" (y)Ponding Depth 12" (y)Ponding Depth 18" (y)
0.0 0.00 0.00 0.00 0.00 0.00
1.0 0.79 0.16 0.11 0.13 0.13
2.0 2.22 0.45 0.24 0.24 0.23
3.0 4.06 0.81 0.37 0.35 0.33
4.0 6.23 1.24 0.51 0.45 0.42
5.0 8.69 1.73 0.65 0.55 0.51
6.0 11.40 2.27 0.79 0.65 0.60
7.0 14.35 2.85 0.94 0.75 0.68
8.0 17.51 3.47 1.08 0.84 0.76
9.0 20.87 4.13 1.23 0.94 0.84
9.2 21.56 4.27 1.26 0.96 0.86
10.0 24.41 4.83 1.38 1.03 0.92
11.0 28.14 5.56 1.54 1.13 1.00
12.0 32.03 6.33 1.69 1.22 1.07
13.0 36.09 7.12 1.85 1.31 1.15
14.0 40.30 7.95 2.01 1.40 1.23
15.0 44.67 8.81 2.16 1.49 1.30
y = Number of inlets
DP 2 Year Flow -cfs 100 Year Flow - cfs
1g 2.28 12.10
Ponding Depth 4 Inches
No. Inlet 100 Year Req to capture 100%33.0
No. of Inlets Provided 3
2 Year Bypass Flow 0 cfs
100 Year Bypass Flow 9.65 cfs
Number of CDOT Type 13 Inlets required for given Capacity at a Sump
Flow Rate (Q)Ponding Depth 4" (y)Ponding Depth 6" (y)Ponding Depth 9" (y)Ponding Depth 12" (y)Ponding Depth 18" (y)
0.0 0.00 0.00 0.00 0.00 0.00
1.0 0.79 0.16 0.11 0.13 0.13
2.0 2.22 0.45 0.24 0.24 0.23
3.0 4.06 0.81 0.37 0.35 0.33
4.0 6.23 1.24 0.51 0.45 0.42
5.0 8.69 1.73 0.65 0.55 0.51
6.0 11.40 2.27 0.79 0.65 0.60
7.0 14.35 2.85 0.94 0.75 0.68
8.0 17.51 3.47 1.08 0.84 0.76
9.0 20.87 4.13 1.23 0.94 0.84
9.2 21.56 4.27 1.26 0.96 0.86
10.0 24.41 4.83 1.38 1.03 0.92
11.0 28.14 5.56 1.54 1.13 1.00
12.0 32.03 6.33 1.69 1.22 1.07
13.0 36.09 7.12 1.85 1.31 1.15
14.0 40.30 7.95 2.01 1.40 1.23
15.0 44.67 8.81 2.16 1.49 1.30
y = Number of inlets
DP 2 Year Flow -cfs 100 Year Flow - cfs
3c 3.14 15.38
Ponding Depth 4 Inches
No. Inlet 100 Year Req to capture 100%47.0
No. of Inlets Provided 5
2 Year Bypass Flow 0 cfs
100 Year Bypass Flow 11.93 cfs
Number of CDOT Type 13 Inlets required for given Capacity at a Sump
Flow Rate (Q)Ponding Depth 4" (y)Ponding Depth 6" (y)Ponding Depth 9" (y)Ponding Depth 12" (y)Ponding Depth 18" (y)
0.0 0.00 0.00 0.00 0.00 0.00
1.0 0.79 0.16 0.11 0.13 0.13
2.0 2.22 0.45 0.24 0.24 0.23
3.0 4.06 0.81 0.37 0.35 0.33
4.0 6.23 1.24 0.51 0.45 0.42
5.0 8.69 1.73 0.65 0.55 0.51
6.0 11.40 2.27 0.79 0.65 0.60
7.0 14.35 2.85 0.94 0.75 0.68
8.0 17.51 3.47 1.08 0.84 0.76
9.0 20.87 4.13 1.23 0.94 0.84
9.2 21.56 4.27 1.26 0.96 0.86
10.0 24.41 4.83 1.38 1.03 0.92
11.0 28.14 5.56 1.54 1.13 1.00
12.0 32.03 6.33 1.69 1.22 1.07
13.0 36.09 7.12 1.85 1.31 1.15
14.0 40.30 7.95 2.01 1.40 1.23
15.0 44.67 8.81 2.16 1.49 1.30
y = Number of inlets
DP 2 Year Flow -cfs 100 Year Flow - cfs
2a 2.17 9.48
Ponding Depth 4 Inches
No. Inlet 100 Year Req to capture 100%23.0
No. of Inlets Provided 4
2 Year Bypass Flow 0 cfs
100 Year Bypass Flow 6.51 cfs
Number of CDOT Type 13 Inlets required for given Capacity at a Sump
Flow Rate (Q)Ponding Depth 4" (y)Ponding Depth 6" (y)Ponding Depth 9" (y)Ponding Depth 12" (y)Ponding Depth 18" (y)
0.0 0.00 0.00 0.00 0.00 0.00
1.0 0.79 0.16 0.11 0.13 0.13
2.0 2.22 0.45 0.24 0.24 0.23
3.0 4.06 0.81 0.37 0.35 0.33
4.0 6.23 1.24 0.51 0.45 0.42
5.0 8.69 1.73 0.65 0.55 0.51
6.0 11.40 2.27 0.79 0.65 0.60
7.0 14.35 2.85 0.94 0.75 0.68
8.0 17.51 3.47 1.08 0.84 0.76
9.0 20.87 4.13 1.23 0.94 0.84
9.2 21.56 4.27 1.26 0.96 0.86
10.0 24.41 4.83 1.38 1.03 0.92
11.0 28.14 5.56 1.54 1.13 1.00
12.0 32.03 6.33 1.69 1.22 1.07
13.0 36.09 7.12 1.85 1.31 1.15
14.0 40.30 7.95 2.01 1.40 1.23
y = Number of inlets
DP 2 Year Flow -cfs 100 Year Flow - cfs
1.2c
Ponding Depth 4 Inches
No. Inlet 100 Year Req to capture 100%5.0
No. of Inlets Provided 1
2 Year Bypass Flow 0 cfs
100 Year Bypass Flow 2.13 cfs
Number of CDOT Type 13 Inlets required for given Capacity at a Sump
Flow Rate (Q)Ponding Depth 4" (y)Ponding Depth 6" (y)Ponding Depth 9" (y)Ponding Depth 12" (y)Ponding Depth 18" (y)
0.0 0.00 0.00 0.00 0.00 0.00
1.0 0.79 0.16 0.11 0.13 0.13
2.0 2.22 0.45 0.24 0.24 0.23
3.0 4.06 0.81 0.37 0.35 0.33
4.0 6.23 1.24 0.51 0.45 0.42
5.0 8.69 1.73 0.65 0.55 0.51
6.0 11.40 2.27 0.79 0.65 0.60
7.0 14.35 2.85 0.94 0.75 0.68
8.0 17.51 3.47 1.08 0.84 0.76
9.0 20.87 4.13 1.23 0.94 0.84
9.2 21.56 4.27 1.26 0.96 0.86
10.0 24.41 4.83 1.38 1.03 0.92
11.0 28.14 5.56 1.54 1.13 1.00
12.0 32.03 6.33 1.69 1.22 1.07
13.0 36.09 7.12 1.85 1.31 1.15
14.0 40.30 7.95 2.01 1.40 1.23
15.0 44.67 8.81 2.16 1.49 1.30
y = Number of inlets
DP 2 Year Flow -cfs 100 Year Flow - cfs
1.3c 0.28 1.24
Ponding Depth 4 Inches
No. Inlet 100 Year Req to capture 100%2.0
No. of Inlets Provided 1
2 Year Bypass Flow 0 cfs
100 Year Bypass Flow 0.07 cfs
Number of CDOT Type 13 Inlets required for given Capacity at a Sump
6'-
0
9 16/"Ø
1
2/
1'
-
1
1
1'
-
1
1
1
2/
1'-95 8/3'-01 2/1'-95 8/
6'-713 16/
72'' ROUND TOP-MOUNT TRASH RACK
LDR-72
0
1 1
101 IRONWOOD ROAD
MIDDLESBORO, KY 40965
PH: (606) 248-5560
FAX: (606) 248-6308
JRHOE.COM
MADE IN THE U.S.A.
AVAILABLE MATERIALS:
MILD STEEL (NO FINISH) - WGT:
MILD STEEL (GALVANIZED) - WGT:
STAINLESS STEEL - WGT:
ALUMINUM - WGT:
CUSTOM SIZES AVAILABLE
AVAILABLE UPON REQUEST WITH:
496.7 lbs.
496.7 lbs.
496.7 lbs.
167.8 lbs.
ACCESS PORT
ANTI-VORTEX PLATE
TITLE:
SIZE DWG. NO.REV.
SHEET /A 118839
Trash Overflow for
J829 and J828
NW Corner of the Site
Subdivision:College and Trilby
Location:West Trilby and South College
Project Name:College and Trilby
Project Number:39793.03
Calculated By:ARJ
Checked By:
Date:4/10/2025
Design Point - J829 and J828 (6 ft. And 8ft. Dia Manhole w/ Trash Rack)
Design flow 102.63 and 20.74 cfs
Orifice Flow Calculation
Q = C*A* square root (2gH)
6' mh
C = 0.6 A = 28.274 sq ft g = 32.2
Head (ft)CA (2GH)Sqrt (2GH)Capacity -CFS
0.57 16.9644 36.60 6.050 102.6
1 16.9644 64.40 8.025 136.1
2 16.9644 128.80 11.349 192.5
3 16.9644 193.20 13.900 235.8
4 16.9644 257.60 16.050 272.3
5 16.9644 322.00 17.944 304.4
6 16.9644 386.40 19.657 333.5
8' mh
C = 0.6 A = 50.27 sq ft g = 32.2
Head (ft)CA (2GH)Sqrt (2GH)Capacity -CFS
0.007341949 30.162 0.47 0.688 20.7
1 30.162 64.40 8.025 242.0
2 30.162 128.80 11.349 342.3
3 30.162 193.20 13.900 419.2
4 30.162 257.60 16.050 484.1
5 30.162 322.00 17.944 541.2
6 30.162 386.40 19.657 592.9
Subdivision:College and Trilby Project Name:College and Trilby
Location:Fort Collins Project No.:
Calculated By:ARJ
Checked By:0
Date:12/19/23
Value Units
Va 4.59 ft/s
Gs 2.5
Gs 32.2 (ft/s ^2 )
C 0.86
D(50)0.29 feet
D(50)4 inches
*using type M riprap - 12"
OVERFLOW CHANNEL CC - RIPRAP CALCULATIONS
39823.00
RIP-RAP METHOD - ISBASH Method
D50 = stone size (ft)
V a = average channel velocity (ft/s)
G s = specific gravity of stone
G = gravitational constant (ft/s ^2 )
C = 0.86 for high turbulence zones 1.20 for low turbulence
zones
FORT COLLINS STORMWATER CRITERIA MANUAL Grading (Ch. 8)
3.0 Detention Basin Grading Design
3.5 Spillway
Page 13
Figure 3.5-1. Spillway Detail and Rock Sizing Chart
EMERCENCY OVERFLOW
SPILLWAY POND P363. TOTAL
INFOW AT POND 363 = 336 CFS
WEIR EQUATION
Q=CLH^(3/2)
C=WEIR COEFFICIENT
L=LENGTH
H=HEIGHT
C=3.0
L=320.5 FT
H=0.496 FT - UNDER 0.5 FT
DESIGN FLOW = 336 CFS
USING TYPE M RIP
RAP W/ TOE WALL
Scenario: 100 Year
C-4.8 (STORM)
C-4.9 (STORM)
C-1.11 (STORM)
C-1.12 (STORM)
C-8.1 (STORM)
C-363.3 (STORM)
C-363.2 (STORM)
C-363.1 (STORM)
C-12.1 (STORM)
C-1.1 (STORM)
C-4.1 (STORM)
C-11.2 (STORM)
C-1.4 (STORM)
C-1.2 (STORM)
C-12.4 (STORM)C-9.1 (STORM)
C-10.1 (STORM)
C-9.2 (STORM)
C-1.5 (STORM)C-13.1 (STORM)
C-1.6 (STORM)
C-19.1 (STORM)C-19.2 (STORM)
C-4.2 (STORM)
C-20.1 (STORM)
C-3.1 (STORM)
C-3.2 (STORM)
C-15.1 (STORM)
C-6.1 (STORM)
C-3.3 (STORM)
C -14.1 (STORM)
C-1.8 (STORM)
C-7.1 (STORM)
C-8.2 (STORM)
C-5.1 (STORM)
C-1.9 (STORM)
C-1.10 (STORM)
C-18.1 (STORM)
C-2.6 (STORM)
C-4.3 (STORM)
C-8.3 (STORM)
C-1.13 (STORM)
C-1.14 (STORM)
C-3.8 (STORM)
C-4.4 (STORM)
C-4.5 (STORM)
O-9
O-12
O-1
O-4
P363
O-3
P363.1 FES (STORM)P363.3 - MH (STORM)
12.4 - MH (STORM)
8.1 - MH (STORM)
1.2 - MH (STORM)
12.3 - MH (STORM)
11.3 - INLET (STORM)
11.4 - INLET (STORM)
11.2 - MH (STORM)
4.2 - MH (STORM)
11.1 - MH (STORM)
1.5 - INLET (STORM)
11.5 - INLET (STORM)
1.4 - MH (STORM)
1.3 - MH (STORM)
12.1 - OULET STRUCTURE (STORM)
12.2 - MH (STORM)9.2 - MH (STORM)
10.1 - INLET (STORM)
11.6 - INLET (STORM)
9.3 - INLET (STORM)
13.1 - INLET (STORM)1.6 - INLET (STORM)
1.7 - MH (STORM)
3.5 - INLET (STORM)
19.2 - INLET (STORM)
19.1 - INLET (STORM)
3.6 - MH (STORM)
2.1 - MH (STORM)
4.3 - MH (STORM)
20.1 - INLET (STORM)
3.3 - MH (STORM)
3.2 - INLET (STORM)
15.1 - INLET (STORM)
1.8 - MH (STORM)
6.1 - INLET (STORM)
2.3 - MH (STORM)
2.4 - MH (STORM)
14.1 - VALLEY INLET (STORM)
3.4 - MH (STORM)
1.9- MH (STORM)
8.2 - INLET (STORM)
7.1 - INLET (STORM)
2.5 - MH (STORM)
22.1 - INLET (STORM)
16.1 - INLET (STORM)
5.1 - MH (STORM)
1.10 - MH (STORM)
5.2 - INLET (STORM)
2.7 - INLET (STORM)
18.1 - INLET (STORM)
1.11 - MH (STORM)
2.6 - MH (STORM)
4.4 - MH (STORM)
17.1 - VALLEY INLET (STORM)
3.7 - MH (STORM)
1.13 - MH (STORM)
8.3 - INLET (STORM)
1.15 - INLET (STORM)
1.14 - MH (STORM)
3.8 - EX INLET (STORM)
3.9 - INLET (STORM)
4.5 - MH (STORM)
4.6 - MH (STORM)
4.7 - MH (STORM)
4.8 - MH (STORM)
4.9 - MH (STORM)
4.10 - MH (STORM)
1.12 - MH (STORM)
P363.2 - MH (STORM)
Page 1 of 176 Watertown Road, Suite 2D Thomaston, CT 06787 USA +1-203-755-16666/25/2025
StormCAD
[10.03.04.53]Bentley Systems, Inc. Haestad Methods Solution Center3979303 StormCAD.stsw
Urban Drainage and Flood Control District
Modeling Hydraulic and Energy Gradients in Storm Sewers: October 6, 2009
Page 19
6.3 Combined Junction Loss Equation
g
Vkg
Vkg
Vkg
V
g
VkHH ofi
bL
fi
m
fofT
bTsj 22222
22222
Equation (13)
where,Hj = UD Sewer junction loss
Hs = Standard method junction loss
kbT = Bend loss coefficient at truckling
kbL = Bend loss coefficient at lateral
VfT = Full flow velocity of trunk line at manhole
Vfi = Full flow velocity of incoming lateral at manhole
Vo = Full flow velocity of trunk line at manhole
k =Head Loss Coefficient
g =Acceleration due to Gravity
Table 2 StormCAD Standard Method Conversions
StormCAD Conversion Table
Be
n
d
L
o
s
s
Bend
Angle K coefficient Conversion
0 0.05
22.5 0.1
45 0.4
60 0.64
90 1.32
La
t
e
r
a
l
L
o
s
s
1 Lateral K coefficient Conversion
Bend
Angle
Non
Surcharged Surcharged
45 0.27 0.47
60 0.52 0.9
90 1.02 1.77
2 Laterals K coefficient Conversion
45 0.96
60 1.16
90 1.52
The engineering guidelines from this study provide the methodology needed to reach an HGL
analysis result using StormCAD which replicates that of UD-Sewer. However, the following
limitations apply:
The full pipe velocity should not exceed 18 fps
The conversion only applies for the storm sewer pipe sizes 42” or less
A regional storm sewer system should use UD-Sewer only
Scenario: 2 Year
Current Time Step: 0.000 h
FlexTable: Conduit Table
X:\3970000.all\3979303\StormCAD\Model\3979303 StormCAD.stsw
Upstream Structure Label Diameter
(in)
Slope
(Calculated)
(ft/ft)
Length
(User
Defined)
(ft)
Manning's
n
Flow
(cfs)
Capacity
(Full
Flow)
(cfs)
Invert
(Start)
(ft)
Invert
(Stop)
(ft)
Elevation
Ground
(Start) (ft)
Elevation
Ground
(Stop) (ft)
Hydraulic
Grade
Line (In)
(ft)
Hydraulic
Grade
Line (Out)
(ft)
Energy
Grade
Line (In)
(ft)
Energy
Grade
Line
(Out) (ft)
Upstream
Structure
Headloss
Coefficient
Velocity
(ft/s)
1.2 - MH (STORM)C-1.1 (STORM)42.0 0.025 70.8 0.013 25.10 158.20 5,001.75 5,000.00 5,015.37 5,003.97 5,003.29 5,001.00 5,003.88 5,002.90 0.050 12.02
1.13 - MH (STORM)C-1.12 (STORM)18.0 0.023 28.8 0.013 1.03 16.03 5,035.90 5,035.23 5,040.48 5,039.65 5,036.28 5,036.24 5,036.41 5,036.25 1.020 5.10
1.15 - INLET (STORM)C-1.14 (STORM)18.0 0.012 47.4 0.013 0.75 11.72 5,037.59 5,037.00 5,041.36 5,041.43 5,037.91 5,037.26 5,038.03 5,037.47 0.100 3.73
1.5 - INLET (STORM)C-1.4 (STORM)42.0 0.019 29.1 0.013 22.43 138.38 5,015.40 5,014.85 5,021.65 5,021.94 5,016.85 5,015.93 5,017.40 5,017.15 0.100 10.58
1.8 - MH (STORM)C-1.7 (STORM)30.0 0.015 251.9 0.013 9.30 50.31 5,026.29 5,022.50 5,032.74 5,028.74 5,027.31 5,023.60 5,027.69 5,023.91 1.020 7.82
1.10 - MH (STORM)C-1.9 (STORM)24.0 0.017 230.2 0.013 5.10 29.45 5,032.90 5,029.00 5,038.47 5,034.54 5,033.70 5,030.43 5,033.99 5,030.50 1.320 7.02
2.4 - MH (STORM)C-2.3 (STORM)30.0 0.019 32.5 0.013 6.54 56.63 5,028.47 5,027.85 5,034.09 5,033.42 5,029.32 5,029.09 5,029.63 5,029.20 0.050 7.69
2.7 - INLET (STORM)C-2.6 (STORM)18.0 0.010 26.3 0.013 1.15 10.45 5,034.23 5,033.97 5,038.68 5,039.34 5,034.63 5,034.67 5,034.77 5,034.70 0.050 3.89
3.3 - MH (STORM)C-3.2 (STORM)48.0 0.005 20.6 0.013 17.65 100.03 5,022.17 5,022.07 5,031.51 5,031.40 5,023.40 5,023.45 5,023.85 5,023.78 0.600 6.00
3.6 - MH (STORM)C-3.5 (STORM)42.0 0.005 109.8 0.013 16.14 71.22 5,024.21 5,023.66 5,029.22 5,029.59 5,025.44 5,024.79 5,025.88 5,025.35 1.770 5.99
3.9 - INLET (STORM)C-3.9 (STORM)24.0 0.022 2.7 0.013 3.03 33.85 5,038.86 5,038.80 5,043.70 5,043.53 5,039.47 5,039.31 5,039.69 5,039.67 0.050 6.67
4.3 - MH (STORM)C-4.2 (STORM)48.0 0.030 120.2 0.013 23.59 248.92 5,015.23 5,011.62 5,030.52 5,020.00 5,016.66 5,012.46 5,017.19 5,014.81 0.500 12.47
4.6 - MH (STORM)C-4.5 (STORM)48.0 0.023 99.3 0.013 23.59 217.18 5,039.40 5,037.13 5,049.47 5,046.81 5,040.83 5,038.04 5,041.36 5,039.90 0.600 11.32
4.9 - MH (STORM)C-4.8 (STORM)-0.010 60.3 0.013 23.59 101.08 5,050.67 5,050.07 5,057.55 5,055.75 5,051.93 5,051.06 5,052.41 5,051.99 1.320 8.09
5.1 - MH (STORM)C-5.1 (STORM)24.0 0.015 54.3 0.013 4.86 27.63 5,033.79 5,032.98 5,038.38 5,038.27 5,034.57 5,034.50 5,034.86 5,034.56 1.520 6.62
7.1 - INLET (STORM)C-7.1 (STORM)18.0 0.092 72.6 0.013 1.26 31.89 5,032.50 5,025.81 5,038.19 5,029.22 5,032.92 5,026.01 5,033.07 5,027.21 0.050 8.78
8.3 - INLET (STORM)C-8.3 (STORM)24.0 0.030 30.7 0.013 2.17 39.18 5,036.78 5,035.86 5,040.55 5,039.62 5,037.29 5,036.18 5,037.47 5,036.85 0.640 6.70
9.3 - INLET (STORM)C-9.2 (STORM)18.0 0.032 65.6 0.013 0.39 18.79 5,023.60 5,021.50 5,028.36 5,025.82 5,023.83 5,021.65 5,023.91 5,021.93 0.100 4.25
11.2 - MH (STORM)C-11.2 (STORM)36.0 0.005 72.5 0.013 3.46 46.98 5,014.01 5,013.65 5,019.38 5,021.74 5,014.59 5,014.40 5,014.79 5,014.50 1.320 3.88
11.5 - INLET (STORM)C-11.5 (STORM)12.0 0.021 81.8 0.013 0.46 5.17 5,018.80 5,017.08 5,021.67 5,019.60 5,019.08 5,017.28 5,019.18 5,017.54 0.050 4.06
12.4 - MH (STORM)C-12.1 (STORM)30.0 0.006 38.4 0.013 12.70 32.44 5,001.90 5,001.66 5,007.25 5,004.26 5,003.10 5,002.75 5,003.56 5,003.34 0.400 6.21
12.1 - OULET STRUCTURE (STORM)C-12.4 (STORM)30.0 0.005 66.4 0.013 12.70 28.91 5,018.50 5,018.17 5,022.71 5,023.96 5,019.70 5,019.56 5,020.16 5,019.88 0.050 5.70
16.1 - INLET (STORM)C-16.1 (STORM)18.0 0.015 17.3 0.013 0.87 12.90 5,034.76 5,034.50 5,038.37 5,038.74 5,035.11 5,035.10 5,035.23 5,035.13 0.050 4.16
18.1 - INLET (STORM)C-18.1 (STORM)18.0 0.016 25.2 0.013 0.78 13.24 5,034.37 5,033.97 5,038.69 5,039.34 5,034.70 5,034.67 5,034.81 5,034.68 0.050 4.10
20.1 - INLET (STORM)C-20.1 (STORM)18.0 0.020 21.6 0.013 0.72 14.83 5,026.95 5,026.52 5,032.28 5,031.51 5,027.27 5,026.74 5,027.38 5,027.04 0.050 4.34
P363.2 - MH (STORM)C-363.2 (STORM)48.0 0.018 83.4 0.013 30.36 191.40 4,998.35 4,996.87 5,008.06 5,008.33 4,999.98 4,999.21 5,000.60 4,999.45 0.500 11.13
Page 1 of 1
6/25/2025file:///C:/Users/WaterR/AppData/Local/Temp/Bentley/StormCAD/2s2t4myo.xml
Scenario: 2 Year
Current Time Step: 0.000 h
FlexTable: Manhole Table
Label
Flow
(Known)
(cfs)
Elevation
(Ground)
(ft)
Elevation
(Invert) (ft)Headloss Method
Hydraulic
Grade
Line (In)
(ft)
Hydraulic
Grade
Line (Out)
(ft)
Velocity
(Out)
(ft/s)
Flow (Total
Out) (cfs)
Headloss
Coefficient
(Standard)
1.5 - INLET (STORM)22.43 5,021.65 5,015.41 Standard 5,016.91 5,016.85 5.94 22.43 0.100
4.5 - MH (STORM)0.00 5,046.81 5,036.13 Standard 5,037.83 5,037.56 5.83 23.59 0.500
12.3 - MH (STORM)0.00 5,018.38 5,011.94 Standard 5,013.16 5,013.14 5.47 12.70 0.050
Page 1 of 2
6/25/2025file:///C:/Users/WaterR/AppData/Local/Temp/Bentley/StormCAD/xryi5yof.xml
Scenario: 100 Year
Current Time Step: 0.000 h
FlexTable: Conduit Table
X:\3970000.all\3979303\StormCAD\Model\3979303 StormCAD.stsw
Upstream Structure Label Diameter
(in)
Slope
(Calculated)
(ft/ft)
Length
(User
Defined)
(ft)
Manning's
n
Flow
(cfs)
Capacity
(Full
Flow)
(cfs)
Invert
(Start)
(ft)
Invert
(Stop)
(ft)
Elevation
Ground
(Start) (ft)
Elevation
Ground
(Stop) (ft)
Hydraulic
Grade
Line (In)
(ft)
Hydraulic
Grade
Line
(Out) (ft)
Energy
Grade
Line (In)
(ft)
Energy
Grade
Line
(Out) (ft)
Upstream
Structure
Headloss
Coefficient
Velocity
(ft/s)
1.2 - MH (STORM)C-1.1 (STORM)42.0 0.025 70.8 0.013 106.50 158.20 5,001.75 5,000.00 5,015.37 5,003.97 5,006.39 5,005.60 5,008.30 5,007.50 0.050 11.07
1.13 - MH (STORM)C-1.12 (STORM)18.0 0.023 28.8 0.013 2.30 16.03 5,035.90 5,035.23 5,040.48 5,039.65 5,037.30 5,037.29 5,037.33 5,037.31 1.020 6.45
1.15 - INLET (STORM)C-1.14 (STORM)18.0 0.012 47.4 0.013 1.17 11.72 5,037.59 5,037.00 5,041.36 5,041.43 5,037.99 5,037.32 5,038.14 5,037.60 0.100 4.24
1.5 - INLET (STORM)C-1.4 (STORM)42.0 0.019 29.1 0.013 91.70 138.38 5,015.40 5,014.85 5,021.65 5,021.94 5,018.37 5,017.88 5,020.10 5,019.55 0.100 15.38
1.8 - MH (STORM)C-1.7 (STORM)30.0 0.015 251.9 0.013 31.65 50.31 5,026.29 5,022.50 5,032.74 5,028.74 5,028.21 5,026.54 5,029.16 5,027.19 1.020 10.83
1.10 - MH (STORM)C-1.9 (STORM)24.0 0.017 230.2 0.013 14.95 29.45 5,032.90 5,029.00 5,038.47 5,034.54 5,034.29 5,031.33 5,034.93 5,031.68 1.320 9.41
2.4 - MH (STORM)C-2.3 (STORM)30.0 0.019 32.5 0.013 21.63 56.63 5,028.47 5,027.85 5,034.09 5,033.42 5,030.34 5,030.42 5,030.81 5,030.72 0.050 10.76
2.7 - INLET (STORM)C-2.6 (STORM)18.0 0.010 26.3 0.013 4.59 10.45 5,034.23 5,033.97 5,038.68 5,039.34 5,037.13 5,037.08 5,037.23 5,037.18 0.050 2.60
3.3 - MH (STORM)C-3.2 (STORM)48.0 0.005 20.6 0.013 74.08 100.03 5,022.17 5,022.07 5,031.51 5,031.40 5,025.23 5,025.21 5,026.03 5,025.97 0.600 8.71
3.6 - MH (STORM)C-3.5 (STORM)42.0 0.005 109.8 0.013 66.52 71.22 5,024.21 5,023.66 5,029.22 5,029.59 5,027.24 5,026.89 5,028.12 5,027.69 1.770 8.41
3.9 - INLET (STORM)C-3.9 (STORM)24.0 0.022 2.7 0.013 22.01 33.85 5,038.86 5,038.80 5,043.70 5,043.53 5,040.54 5,040.33 5,041.49 5,041.46 0.050 11.47
4.3 - MH (STORM)C-4.2 (STORM)48.0 0.030 120.2 0.013 102.63 248.92 5,015.23 5,011.62 5,030.52 5,020.00 5,018.30 5,013.58 5,019.83 5,017.94 0.500 18.85
4.6 - MH (STORM)C-4.5 (STORM)48.0 0.023 99.3 0.013 102.63 217.18 5,039.40 5,037.13 5,049.47 5,046.81 5,042.47 5,039.27 5,044.00 5,042.77 0.600 17.04
4.9 - MH (STORM)C-4.8 (STORM)-0.010 60.3 0.013 102.63 101.08 5,050.67 5,050.07 5,057.55 5,055.75 5,053.25 5,052.45 5,055.10 5,054.56 1.320 12.06
5.1 - MH (STORM)C-5.1 (STORM)24.0 0.015 54.3 0.013 15.84 27.63 5,033.79 5,032.98 5,038.38 5,038.27 5,036.56 5,036.29 5,036.96 5,036.69 1.520 5.04
7.1 - INLET (STORM)C-7.1 (STORM)18.0 0.092 72.6 0.013 6.27 31.89 5,032.50 5,025.81 5,038.19 5,029.22 5,033.47 5,028.79 5,033.89 5,028.99 0.050 14.02
8.3 - INLET (STORM)C-8.3 (STORM)24.0 0.030 30.7 0.013 2.97 39.18 5,036.78 5,035.86 5,040.55 5,039.62 5,038.20 5,038.21 5,038.23 5,038.22 0.640 7.35
9.3 - INLET (STORM)C-9.2 (STORM)18.0 0.032 65.6 0.013 1.95 18.79 5,023.60 5,021.50 5,028.36 5,025.82 5,025.62 5,025.60 5,025.64 5,025.62 0.100 1.10
11.2 - MH (STORM)C-11.2 (STORM)36.0 0.005 72.5 0.013 22.18 46.98 5,014.01 5,013.65 5,019.38 5,021.74 5,018.20 5,018.12 5,018.36 5,018.28 1.320 3.14
11.5 - INLET (STORM)C-11.5 (STORM)12.0 0.021 81.8 0.013 2.01 5.17 5,018.80 5,017.08 5,021.67 5,019.60 5,019.40 5,018.63 5,019.66 5,018.74 0.050 6.17
12.4 - MH (STORM)C-12.1 (STORM)30.0 0.006 38.4 0.013 51.59 32.44 5,001.90 5,001.66 5,007.25 5,004.26 5,006.21 5,005.60 5,007.92 5,007.32 0.400 10.51
12.1 - OULET STRUCTURE (STORM)C-12.4 (STORM)30.0 0.005 66.4 0.013 51.59 28.91 5,018.50 5,018.17 5,022.71 5,023.96 5,022.61 5,021.56 5,024.33 5,023.28 0.050 10.51
16.1 - INLET (STORM)C-16.1 (STORM)18.0 0.015 17.3 0.013 3.01 12.90 5,034.76 5,034.50 5,038.37 5,038.74 5,036.05 5,036.04 5,036.10 5,036.09 0.050 5.95
18.1 - INLET (STORM)C-18.1 (STORM)18.0 0.016 25.2 0.013 3.60 13.24 5,034.37 5,033.97 5,038.69 5,039.34 5,037.11 5,037.08 5,037.17 5,037.14 0.050 2.04
20.1 - INLET (STORM)C-20.1 (STORM)18.0 0.020 21.6 0.013 4.40 14.83 5,026.95 5,026.52 5,032.28 5,031.51 5,027.75 5,027.12 5,028.08 5,027.82 0.050 7.32
P363.2 - MH (STORM)C-363.2 (STORM)48.0 0.018 83.4 0.013 55.00 191.40 4,998.35 4,996.87 5,008.06 5,008.33 5,000.58 5,000.25 5,001.49 5,000.61 0.500 13.16
Page 1 of 1
6/25/2025file:///C:/Users/WaterR/AppData/Local/Temp/Bentley/StormCAD/rmegs1wu.xml
Scenario: 100 Year
Current Time Step: 0.000 h
FlexTable: Manhole Table
Label
Flow
(Known)
(cfs)
Elevation
(Ground)
(ft)
Elevation
(Invert) (ft)Headloss Method
Hydraulic
Grade
Line (In)
(ft)
Hydraulic
Grade
Line (Out)
(ft)
Velocity
(Out)
(ft/s)
Flow (Total
Out) (cfs)
Headloss
Coefficient
(Standard)
1.5 - INLET (STORM)91.70 5,021.65 5,015.41 Standard 5,018.54 5,018.37 10.55 91.70 0.100
4.5 - MH (STORM)0.00 5,046.81 5,036.13 Standard 5,039.96 5,039.20 9.92 102.63 0.500
12.3 - MH (STORM)0.00 5,018.38 5,011.94 Standard 5,014.35 5,014.26 10.86 51.59 0.050
Page 1 of 2
6/25/2025file:///C:/Users/WaterR/AppData/Local/Temp/Bentley/StormCAD/us4jf5kd.xml
Subdivision:College and Trilby Project Name:College and Trilby
Location:Fort Collins Project No.:39823.00
Calculated By:ARJ
Checked By:0
Date:4/9/25
DESIGN POINT DESIGN POINT DESIGN POINT DESIGN POINT DESIGN POINT Notes
6.1 4.1 P366_WQCV_OUTLET 3.2 J828
Q100 (cfs):74.3 18.5 51.55 106.5 123.57
Conduit Pipe Pipe Pipe Pipe Pipe
D c , Pipe Diameter (in):48 24 30 42 48
W , Box Width (ft):N/A N/A N/A N/A N/A
H , Box Height (ft):N/A N/A N/A N/A N/A
Y t , Tailwater Depth (ft):1.60 0.80 3.00 1.40 1.60 If unknown, use Y t /D c (or H )=0.4
Y t /Dc or Y t /H 0.40 0.40 1.20 0.40 0.40
Q/D2.5 or Q/(WH3/2)2.32 3.26 5.22 4.65 3.86
Supercritical?Yes Yes Yes Yes Yes
Y n , Normal Depth (ft) [Supercritical]:
D a ,H a (in) [Supercritical]:2.00 1.00 1.25 1.75 2.00 D a =(D c +Y n )/2
Riprap d 50 (in) [Supercritical]:9.48 6.66 3.56 16.60 15.76
Riprap d 50 (in) [Subcritical]:N/A N/A N/A N/A N/A
Required Riprap Size:M L L H H Fig. 9-38 or Fig. 9-36
d 50 (in):12 9 9 15 15 Use Type M (MIN.)
Expansion Factor, 1/(2 tan):6.00 6.00 7.00 6.00 6.00 Read from Fig. 9-35 or 9-36
0.08 0.08 0.07 0.08 0.08
Erosive Soils?No No No No No
Area of Flow,A t (ft2):10.62 2.64 7.36 15.21 17.65 A t =Q/V
Length of Protection, L p (ft):15.8 7.8 -0.3 44.2 42.2 L=(1/(2 tan ))(At/Yt - D)
Min Length (ft)12.0 6.0 7.5 10.5 12.0 Min L=3D or 3H
Max Length (ft)40.0 20.0 25.0 35.0 40.0 Max L=10D or 10H
Min Bottom Width,T (ft):6.6 3.3 2.5 10.9 11.0 T=2*(Lp*tan)+W
Design Length (ft)16.0 8.0 7.5 35.0 40.0
Design Width (ft)6.6 3.3 2.5 10.9 11.0
Riprap Depth (in)24 18 18 30 30 Depth=2(d50)
Type II Bedding Depth (in)*6 6 6 8 8 *Not used if Soil Riprap
Cutoff Wall Yes Yes Yes Yes Yes
Cutoff Wall Depth (in)30.0 24.0 24.0 38.0 38.0 Depth of Riprap and Base
Cutoff Wall Width (ft)10.0 7.3 8.3 9.5 10.0
* For use when the flow in the culvert is supercritical (and less than full).
STORM DRAIN SYSTEM
PIPE OUTFALL RIPRAP SIZING CALCULATIONS
X:\3970000.all\3979303\Excel\Drainage\3979303 Drainage_Calcs_Template_v2.07.xlsm Page 1 of 3 4/10/2025
X:\3970000.all\3979303\Excel\Drainage\3979303 Drainage_Calcs_Template_v2.07.xlsm Page 2 of 3 4/10/2025
For Supercritical
X:\3970000.all\3979303\Excel\Drainage\3979303 Drainage_Calcs_Template_v2.07.xlsm Page 3 of 3 4/10/2025
College & Trilby Multi-Family Community
Final Drainage Report
APPENDIX D – WATER QUALITY CALCULATIONS
Subdivision:College and Trilby Project Name:College and Trilby
Location:Fort Collins Project No.:39823.00
Calculated By:ARJ
Checked By:0
Date:4/23/24
Basin (ac)% Imp.
B1 0.63 77.5%
B2 1.17 9.1%
D1 0.29 81.4%
D2 0.50 67.2%
E1 0.42 81.3%
E2 0.73 78.1%
E3 0.23 78.1%
E4 0.17 62.6%
E5 0.38 36.2%
E6 0.86 6.3%
OS1 0.74 82.0%
OS2 2.03 48.3%
OS3 0.32 71.5%
B770A 0.36 100.0%
B770B 1.52 89.0%
B900A 0.48 95.0%
B900B 0.56 100.0%
B910C 1.30 90.0%
B920C 1.71 66.0%
B910D 0.46 90.0%
B920A 3.82 20.0%
B920B 0.99 63.0%
WQCV Drain Time (hr):40
Coefficient, a (Figure 3.2):1.0
WQCV (in):0.23
WQ Pond Tributary Areas
POND 366
X:\3970000.all\3979303\Excel\Drainage\3979303 Drainage_Calcs_Template_v2.07.xlsm Page 1 of 3 4/24/2024
Subdivision:College and Trilby Project Name:College and Trilby
Location:Fort Collins Project No.:39823.00
Calculated By:ARJ
Checked By:0
Date:4/23/24
Basin (ac)Value % Imp.
A1 1.90 0.16 15.6%
A2 1.76 0.12 51.6%
A3 0.31 0.07 72.3%
A4 1.65 0.13 47.4%
A5 0.42 0.10 59.3%
A6 0.75 0.07 68.6%
A7 0.47 0.09 71.2%
A8 1.23 0.09 62.0%
A9 0.30 0.09 65.6%
C1.1 3.84 0.13 47.0%
C1.2 0.72 0.19 37.8%
C1.3 0.18 0.07 68.1%
C2 1.12 0.11 55.2%
C3 1.91 0.05 76.1%
C4 2.55 0.10 58.0%
C5 1.34 0.09 63.6%
G1 1.49 0.05 72.2%
G2 0.62 0.02 83.0%
G3 1.06 0.08 52.4%
G4 0.82 0.03 80.7%
WQCV Drain Time (hr):12
Coefficient, a (Figure 3.2):0.8
WQCV (in):0.18
WQ Pond Tributary Areas
ADS Isolator Rows
X:\3970000.all\3979303\Excel\Drainage\3979303 Drainage_Calcs_Template_v2.07.xlsm Page 2 of 3 4/24/2024
X:\3970000.all\3979303\Excel\Drainage\3979303 Drainage_Calcs_Template_v2.07.xlsm Page 3 of 3 4/24/2024
Project:
Basin ID:
Depth Increment =1.00 ft
Watershed Information Top of Micropool --0.00 ------0 0.000
Selected BMP Type =EDB 5020 --0.75 ------3,204 0.074 1,201 0.028
Watershed Area =19.66 acres 5021 --1.75 ------9,840 0.226 7,724 0.177
Watershed Length =1,677 ft 5022 --2.75 ------13,392 0.307 19,340 0.444
Watershed Length to Centroid =1,006 ft 5023 --3.75 ------15,949 0.366 34,010 0.781
Watershed Slope =0.029 ft/ft 5024 --4.75 ------18,716 0.430 51,343 1.179
Watershed Imperviousness =56.90%percent 5025 --5.75 ------22,031 0.506 71,716 1.646
Percentage Hydrologic Soil Group A =0.0%percent 5026 --6.75 ------25,665 0.589 95,564 2.194
Percentage Hydrologic Soil Group B =0.0%percent --------
Percentage Hydrologic Soil Groups C/D =100.0%percent --------
Target WQCV Drain Time =40.0 hours --------
Location for 1-hr Rainfall Depths = User Input --------
--------
--------
Optional User Overrides --------
Water Quality Capture Volume (WQCV) =0.444 acre-feet 0.444 acre-feet --------
Excess Urban Runoff Volume (EURV) =1.069 acre-feet acre-feet --------
2-yr Runoff Volume (P1 = 0.82 in.) =0.699 acre-feet 0.82 inches --------
5-yr Runoff Volume (P1 = 1.09 in.) =1.033 acre-feet inches --------
10-yr Runoff Volume (P1 = 1.4 in.) =1.508 acre-feet 1.40 inches --------
25-yr Runoff Volume (P1 = 1.69 in.) =2.050 acre-feet inches --------
50-yr Runoff Volume (P1 = 1.99 in.) =2.552 acre-feet inches --------
100-yr Runoff Volume (P1 = 2.86 in.) =4.103 acre-feet 2.86 inches --------
500-yr Runoff Volume (P1 = 3.14 in.) =4.589 acre-feet inches --------
Approximate 2-yr Detention Volume =0.655 acre-feet --------
Approximate 5-yr Detention Volume =1.003 acre-feet --------
Approximate 10-yr Detention Volume =1.259 acre-feet --------
Approximate 25-yr Detention Volume =1.428 acre-feet --------
Approximate 50-yr Detention Volume =1.544 acre-feet --------
Approximate 100-yr Detention Volume =2.209 acre-feet --------
--------
Define Zones and Basin Geometry --------
Zone 1 Volume (WQCV) =0.444 acre-feet --------
Zone 2 Volume (User Defined - Zone 1) =0.000 acre-feet --------
0.000 acre-feet --------
Total Detention Basin Volume =0.444 acre-feet --------
Initial Surcharge Volume (ISV) =user ft 3 --------
Initial Surcharge Depth (ISD) =user ft --------
Total Available Detention Depth (Htotal) =user ft --------
Depth of Trickle Channel (HTC) =user ft --------
Slope of Trickle Channel (STC) =user ft/ft --------
Slopes of Main Basin Sides (Smain) =user H:V --------
Basin Length-to-Width Ratio (RL/W) =user --------
--------
Initial Surcharge Area (AISV) =user ft 2 --------
Surcharge Volume Length (LISV) =user ft --------
Surcharge Volume Width (WISV) =user ft --------
Depth of Basin Floor (HFLOOR) =user ft --------
Length of Basin Floor (LFLOOR) =user ft --------
Width of Basin Floor (WFLOOR) =user ft --------
Area of Basin Floor (AFLOOR) =user ft 2 --------
Volume of Basin Floor (VFLOOR) =user ft 3 --------
Depth of Main Basin (HMAIN) =user ft --------
Length of Main Basin (LMAIN) =user ft --------
Width of Main Basin (WMAIN) =user ft --------
Area of Main Basin (AMAIN) =user ft 2 --------
Volume of Main Basin (VMAIN) =user ft 3 --------
Calculated Total Basin Volume (Vtotal) =user acre-feet --------
Total detention
volume is less than
100-year volume.
After providing required inputs above including 1-hour rainfall
depths, click 'Run CUHP' to generate runoff hydrographs using
the embedded Colorado Urban Hydrograph Procedure.
Volume
(ft 3)
Volume
(ac-ft)
Area
(acre)
DETENTION BASIN STAGE-STORAGE TABLE BUILDER
Override
Area (ft 2)
Length
(ft)
Override
Stage (ft)
Stage
(ft)
Stage - Storage
Description
Area
(ft 2)
Width
(ft)
College and Trilby WQ Pond 366. WQ by factor of 1.2
Pond 366
MHFD-Detention, Version 4.06 (July 2022)
Example Zone Configuration (Retention Pond)
Pond 366 MHFD-Detention_v4-06.xlsm, Basin 12/6/2024, 11:13 AM
1 User Defined Stage-Area Booleans for Message
1 Equal Stage-Area Inputs Watershed L:W
1 CountA Watershed Lc:L
Watershed Slope
0 Calc_S_TC Booleans for CUHP
1 CUHP Inputs Complete
H_FLOOR 1 CUHP Results Calculated
L_FLOOR_OTHER
0.00 ISV 0.00 ISV
0.00 Floor 0.00 Floor
2.76 Zone 1 (WQCV)2.76 Zone 1 (WQCV)
2.76 Zone 2 (User)2.76 Zone 1 (WQCV)
2.76 Zone 3 (User)2.76 Zone 1 (WQCV)
DETENTION BASIN STAGE-STORAGE TABLE BUILDER
MHFD-Detention, Version 4.06 (July 2022)
0.000
0.550
1.100
1.650
2.200
0.000
0.150
0.300
0.450
0.600
0.00 2.00 4.00 6.00 8.00
Vo
l
u
m
e
(
a
c
-
f
t
)
Ar
e
a
(
a
c
r
e
s
)
Stage (ft.)
Area (acres)Volume (ac-ft)
0
6500
13000
19500
26000
0
5
10
15
20
0.00 2.00 4.00 6.00 8.00
Ar
e
a
(
s
q
.
f
t
.
)
Le
n
g
t
h
,
W
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d
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.
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Stage (ft)
Length (ft)Width (ft)Area (sq.ft.)
Pond 366 MHFD-Detention_v4-06.xlsm, Basin 12/6/2024, 11:13 AM
Project:
Basin ID:
Estimated Estimated
Stage (ft)Volume (ac-ft)Outlet Type
Zone 1 (WQCV)2.76 0.444 Orifice Plate
Zone 2 (User)2.76 0.000 Weir&Pipe (Restrict)
Zone 3 (User)2.76 0.000 Weir&Pipe (Restrict)
Total (all zones)0.444
User Input: Orifice at Underdrain Outlet (typically used to drain WQCV in a Filtration BMP)Calculated Parameters for Underdrain
Underdrain Orifice Invert Depth =N/A ft (distance below the filtration media surface)Underdrain Orifice Area =N/A ft2
Underdrain Orifice Diameter =N/A inches Underdrain Orifice Centroid =N/A feet
User Input: Orifice Plate with one or more orifices or Elliptical Slot Weir (typically used to drain WQCV and/or EURV in a sedimentation BMP)Calculated Parameters for Plate
Centroid of Lowest Orifice =0.00 ft (relative to basin bottom at Stage = 0 ft)WQ Orifice Area per Row =1.306E-02 ft2
Depth at top of Zone using Orifice Plate =2.76 ft (relative to basin bottom at Stage = 0 ft)Elliptical Half-Width =N/A feet
Orifice Plate: Orifice Vertical Spacing =12.10 inches Elliptical Slot Centroid =N/A feet
Orifice Plate: Orifice Area per Row =1.88 sq. inches (diameter = 1-9/16 inches)Elliptical Slot Area =N/A ft2
User Input: Stage and Total Area of Each Orifice Row (numbered from lowest to highest)
Row 1 (required)Row 2 (optional)Row 3 (optional)Row 4 (optional)Row 5 (optional)Row 6 (optional)Row 7 (optional)Row 8 (optional)
Stage of Orifice Centroid (ft)0.00 0.92 1.84
Orifice Area (sq. inches)1.88 1.88 1.88
Row 9 (optional)Row 10 (optional)Row 11 (optional)Row 12 (optional)Row 13 (optional)Row 14 (optional)Row 15 (optional)Row 16 (optional)
Stage of Orifice Centroid (ft)
Orifice Area (sq. inches)
User Input: Vertical Orifice (Circular or Rectangular)
Not Selected Not Selected Not Selected Not Selected
Invert of Vertical Orifice =N/A N/A ft (relative to basin bottom at Stage = 0 ft)Vertical Orifice Area =N/A N/A
Depth at top of Zone using Vertical Orifice =N/A N/A ft (relative to basin bottom at Stage = 0 ft)Vertical Orifice Centroid =N/A N/A
Vertical Orifice Diameter =N/A N/A inches
User Input: Overflow Weir (Dropbox with Flat or Sloped Grate and Outlet Pipe OR Rectangular/Trapezoidal Weir and No Outlet Pipe)
grate Zone 2 Weir Zone 3 Weir Zone 2 Weir Zone 3 Weir
Overflow Weir Front Edge Height, Ho =2.76 ft (relative to basin bottom at Stage = 0 ft)Height of Grate Upper Edge, Ht =4.26
Overflow Weir Front Edge Length =5.00 feet Overflow Weir Slope Length =6.18
Overflow Weir Grate Slope =4.00 H:V Grate Open Area / 100-yr Orifice Area =4.98
Horiz. Length of Weir Sides =6.00 feet Overflow Grate Open Area w/o Debris =24.46
Overflow Grate Type = Close Mesh Grate Overflow Grate Open Area w/ Debris =24.46
Debris Clogging % =0%%
User Input: Outlet Pipe w/ Flow Restriction Plate (Circular Orifice, Restrictor Plate, or Rectangular Orifice)
Zone 2 Restrictor Zone 3 Restrictor Zone 2 Restrictor Zone 3 Restrictor
Depth to Invert of Outlet Pipe =0.75 ft (distance below basin bottom at Stage = 0 ft)Outlet Orifice Area =4.91
Outlet Pipe Diameter =30.00 inches Outlet Orifice Centroid =1.25
Restrictor Plate Height Above Pipe Invert =30.00 inches Half-Central Angle of Restrictor Plate on Pipe =3.14
User Input: Emergency Spillway (Rectangular or Trapezoidal)Calculated Parameters for Spillway
Spillway Invert Stage=ft (relative to basin bottom at Stage = 0 ft)Spillway Design Flow Depth=feet
Spillway Crest Length =feet Stage at Top of Freeboard =feet
Spillway End Slopes =H:V Basin Area at Top of Freeboard =acres
Freeboard above Max Water Surface =feet Basin Volume at Top of Freeboard =acre-ft
Max Ponding Depth of Target Storage Volume =#N/A feet Discharge at Top of Freeboard =cfs
Routed Hydrograph Results
Design Storm Return Period =WQCV EURV 2 Year 5 Year 10 Year 25 Year 50 Year 100 Year
One-Hour Rainfall Depth (in) =N/A N/A 0.82 1.09 1.40 1.69 1.99 2.86
CUHP Runoff Volume (acre-ft) =0.444 1.069 0.699 1.033 1.508 2.050 2.552 4.103
Inflow Hydrograph Volume (acre-ft) =N/A N/A 0.699 1.033 1.508 2.050 2.552 4.103
CUHP Predevelopment Peak Q (cfs) =N/A N/A 0.2 1.4 5.0 10.9 15.0 28.2
OPTIONAL Override Predevelopment Peak Q (cfs) =N/A N/A
Predevelopment Unit Peak Flow, q (cfs/acre) =N/A N/A 0.01 0.07 0.26 0.55 0.76 1.44
Peak Inflow Q (cfs) =N/A N/A 9.5 14.1 20.9 29.5 36.8 59.0
Peak Outflow Q (cfs) =0.2 37.9 2.1 5.7 11.0 20.9 28.2 47.2
Ratio Peak Outflow to Predevelopment Q =N/A N/A N/A 4.0 2.2 1.9 1.9 1.7
Structure Controlling Flow =Overflow Weir 1 Outlet Plate 1 Overflow Weir 1 Overflow Weir 1 Overflow Weir 1 Overflow Weir 1 Overflow Weir 1 Outlet Plate 1
Max Velocity through Grate 1 (fps) =N/A 1.92 0.07 0.2 0.4 0.8 1.1 1.9
Max Velocity through Grate 2 (fps) =N/A N/A N/A N/A N/A N/A N/A N/A
Time to Drain 97% of Inflow Volume (hours) =37 36 39 37 35 32 30 25
Time to Drain 99% of Inflow Volume (hours) =40 41 43 42 41 40 39 35
Maximum Ponding Depth (ft) =2.76 4.49 3.02 3.25 3.49 3.79 3.97 4.48
Area at Maximum Ponding Depth (acres) =0.31 0.41 0.32 0.34 0.35 0.37 0.38 0.41
Maximum Volume Stored (acre-ft) =0.447 1.069 0.529 0.605 0.684 0.795 0.859 1.065
DETENTION BASIN OUTLET STRUCTURE DESIGN
MHFD-Detention, Version 4.06 (July 2022)
College and Trilby WQ Pond 366. WQ by factor of 1.2
Pond 366
The user can override the default CUHP hydrographs and runoff volumes by entering new values in the Inflow Hydrographs table (Columns W through AF).
Example Zone Configuration (Retention Pond)
Pond 366 MHFD-Detention_v4-06.xlsm, Outlet Structure 12/6/2024, 11:14 AM
COUNTA for Basin Tab =1 Ao Dia WQ Plate Type Vert Orifice 2
Count_Underdrain =0 0.11 2 1 1
Count_WQPlate =1 0.14
Count_VertOrifice1 =0 0.18 Outlet Plate 1 Outlet Plate 2 Drain Time Message Boolean
Count_VertOrifice2 =0 0.24 4 4 5yr, <72hr 0
Count_Weir1 =1 0.29 >5yr, <120hr 0
Count_Weir2 =0 0.36 Max Depth Row
Count_OutletPipe1 =1 0.42 WQCV 277
Count_OutletPipe2 =0 0.50 2 Year 303
COUNTA_2 (Standard FSD Setup)=1 0.58 EURV 450
Hidden Parameters & Calculations 0.67 5 Year 326
MaxPondDepth_Error?FALSE 0.76 10 Year 350 Spillway Depth
Cd_Broad-Crested Weir 3.00 0.86 25 Year 380
WQ Plate Flow at 100yr depth =0.35 0.97 50 Year 398
CLOG #1=100%1.08 100 Year 449 1 Z1_Boolean
n*Cdw #1 =0.44 1.20 500 Year 481 1 Z2_Boolean
n*Cdo #1 =1.83 1.32 Zone3_Pulldown Message 0 Z3_Boolean
Overflow Weir #1 Angle =0.245 1.45 1 Opening Message
CLOG #2=100%1.59 Draintime Running
n*Cdw #2 =0.00 1.73 Outlet Boolean Outlet Rank Total (1 to 4)
n*Cdo #2 =0.00 1.88 Vertical Orifice 1 0 0 1
Overflow Weir #2 Angle =0.000 2.03 Vertical Orifice 2 0 0 Boolean
Underdrain Q at 100yr depth =0.00 2.20 Overflow Weir 1 1 1 0 Max Depth
VertOrifice1 Q at 100yr depth =0.00 2.36 Overflow Weir 2 0 0 0 500yr Depth
VertOrifice2 Q at 100yr depth =0.00 2.54 Outlet Pipe 1 1 1 0 Freeboard
2.72 Outlet Pipe 2 0 0 0 Spillway
Count_User_Hydrographs 0 2.90 0 Spillway Length
CountA_3 (EURV & 100yr) =1 3.09 FALSE Time Interval
CountA_4 (100yr Only) =1 3.29 Button Visibility Boolean
COUNTA_5 (FSD Weir Only)=0 0 WQCV Underdrain
COUNTA_6 (EURV Weir Only)=1 1 WQCV Plate
0 EURV-WQCV Plate
Outlet1_Pulldown_Boolean 0 EURV-WQCV VertOriice
Outlet2_Pulldown_Boolean 0 Outlet 90% Qpeak
Outlet3_Pulldown_Boolean 0 Outlet Undetained
0 Weir Only 90% Qpeak
0 Five Year Ratio Plate
0 Five Year Ratio VertOrifice
EURV_draintime_user
Spillway Options
Offset
Overlapping
S-A-V-D Chart Axis Default X-axis Left Y-Axis Right Y-Axis
minimum bound 0.00 0 0
maximum bound 6.00 60,000 50
S-A-V-D Chart Axis Override X-axis Left Y-Axis Right Y-Axis
minimum bound
maximum bound
DETENTION BASIN OUTLET STRUCTURE DESIGN
MHFD-Detention, Version 4.06 (July 2022)
0
10
20
30
40
50
60
70
0.1 1 10
FL
O
W
[
c
f
s
]
TIME [hr]
500YR IN
500YR OUT
100YR IN
100YR OUT
50YR IN
50YR OUT
25YR IN
25YR OUT
10YR IN
10YR OUT
5YR IN
5YR OUT
2YR IN
2YR OUT
EURV IN
EURV OUT
WQCV IN
WQCV OUT
0
1
2
3
4
5
6
0.1 1 10 100
PO
N
D
I
N
G
D
E
P
T
H
[
f
t
]
DRAIN TIME [hr]
500YR
100YR
50YR
25YR
10YR
5YR
2YR
EURV
WQCV
0
5
10
15
20
25
30
35
40
45
50
0
10,000
20,000
30,000
40,000
50,000
60,000
0.00 1.00 2.00 3.00 4.00 5.00 6.00
OU
T
F
L
O
W
[
c
f
s
]
AR
E
A
[
f
t
^
2
]
,
V
O
L
U
M
E
[
f
t
^
3
]
PONDING DEPTH [ft]
User Area [ft^2]
Interpolated Area [ft^2]
Summary Area [ft^2]
Volume [ft^3]
Summary Volume [ft^3]
Outflow [cfs]
Summary Outflow [cfs]
Pond 366 MHFD-Detention_v4-06.xlsm, Outlet Structure 12/6/2024, 11:14 AM
Outflow Hydrograph Workbook Filename:
Inflow Hydrographs
The user can override the calculated inflow hydrographs from this workbook with inflow hydrographs developed in a separate program.
SOURCE CUHP CUHP CUHP CUHP CUHP CUHP CUHP CUHP CUHP
Time Interval TIME WQCV [cfs]EURV [cfs]2 Year [cfs] 5 Year [cfs] 10 Year [cfs] 25 Year [cfs] 50 Year [cfs] 100 Year [cfs] 500 Year [cfs]
5.00 min 0:00:00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00
0:05:00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00
0:10:00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.31 0.54
0:15:00 0.00 0.00 0.38 1.19 1.99 1.38 2.01 3.08 3.58
0:20:00 0.00 0.00 3.09 4.62 6.30 4.16 5.26 7.92 9.10
0:25:00 0.00 0.00 7.33 11.01 16.55 9.77 12.36 20.80 24.05
0:30:00 0.00 0.00 9.47 14.14 20.92 24.38 30.93 48.32 54.26
0:35:00 0.00 0.00 9.17 13.60 19.84 29.45 36.82 58.98 65.82
0:40:00 0.00 0.00 8.43 12.27 17.85 29.27 36.33 57.83 64.43
0:45:00 0.00 0.00 7.43 10.92 15.99 26.81 33.22 54.04 60.17
0:50:00 0.00 0.00 6.56 9.81 14.14 24.60 30.44 49.43 55.04
0:55:00 0.00 0.00 5.81 8.65 12.49 21.64 26.83 44.42 49.46
1:00:00 0.00 0.00 5.15 7.62 11.05 18.89 23.45 39.85 44.37
1:05:00 0.00 0.00 4.68 6.89 10.06 16.55 20.58 35.95 40.05
1:10:00 0.00 0.00 4.19 6.39 9.40 14.35 17.92 30.85 34.43
1:15:00 0.00 0.00 3.77 5.82 8.83 12.63 15.83 26.63 29.76
1:20:00 0.00 0.00 3.39 5.20 7.95 10.92 13.66 22.29 24.91
1:25:00 0.00 0.00 3.04 4.61 6.83 9.36 11.68 18.42 20.57
1:30:00 0.00 0.00 2.69 4.06 5.79 7.80 9.70 15.03 16.78
1:35:00 0.00 0.00 2.37 3.57 4.90 6.37 7.88 11.98 13.37
1:40:00 0.00 0.00 2.13 3.05 4.24 5.13 6.32 9.39 10.49
1:45:00 0.00 0.00 2.01 2.70 3.85 4.23 5.19 7.58 8.49
1:50:00 0.00 0.00 1.95 2.48 3.61 3.70 4.52 6.46 7.25
1:55:00 0.00 0.00 1.74 2.33 3.39 3.35 4.09 5.72 6.42
2:00:00 0.00 0.00 1.56 2.16 3.10 3.12 3.79 5.18 5.82
2:05:00 0.00 0.00 1.25 1.72 2.47 2.47 2.99 4.01 4.50
2:10:00 0.00 0.00 0.97 1.33 1.91 1.89 2.28 2.98 3.35
2:15:00 0.00 0.00 0.75 1.03 1.47 1.44 1.74 2.22 2.50
2:20:00 0.00 0.00 0.58 0.79 1.12 1.10 1.32 1.67 1.87
2:25:00 0.00 0.00 0.45 0.60 0.84 0.83 0.99 1.26 1.42
2:30:00 0.00 0.00 0.34 0.45 0.62 0.62 0.74 0.95 1.06
2:35:00 0.00 0.00 0.25 0.33 0.47 0.46 0.55 0.71 0.79
2:40:00 0.00 0.00 0.19 0.24 0.35 0.35 0.41 0.53 0.60
2:45:00 0.00 0.00 0.13 0.18 0.25 0.25 0.30 0.39 0.44
2:50:00 0.00 0.00 0.09 0.12 0.17 0.18 0.21 0.27 0.31
2:55:00 0.00 0.00 0.05 0.08 0.11 0.11 0.14 0.17 0.19
3:00:00 0.00 0.00 0.03 0.04 0.06 0.07 0.08 0.10 0.11
3:05:00 0.00 0.00 0.01 0.02 0.03 0.03 0.03 0.04 0.05
3:10:00 0.00 0.00 0.00 0.01 0.01 0.01 0.01 0.01 0.01
3:15:00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00
3:20:00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00
3:25:00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00
3:30:00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00
3:35:00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00
3:40:00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00
3:45:00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00
3:50:00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00
3:55:00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00
4:00:00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00
4:05:00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00
4:10:00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00
4:15:00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00
4:20:00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00
4:25:00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00
4:30:00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00
4:35:00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00
4:40:00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00
4:45:00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00
4:50:00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00
4:55:00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00
5:00:00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00
5:05:00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00
5:10:00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00
5:15:00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00
5:20:00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00
5:25:00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00
5:30:00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00
5:35:00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00
5:40:00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00
5:45:00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00
5:50:00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00
5:55:00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00
6:00:00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00
DETENTION BASIN OUTLET STRUCTURE DESIGN
Pond 366 MHFD-Detention_v4-06.xlsm, Outlet Structure 12/6/2024, 11:14 AM
Summary Stage-Area-Volume-Discharge Relationships
The user can create a summary S-A-V-D by entering the desired stage increments and the remainder of the table will populate automatically.
The user should graphically compare the summary S-A-V-D table to the full S-A-V-D table in the chart to confirm it captures all key transition points.
Stage Area Area Volume Volume
[ft][ft 2][acres][ft 3][ac-ft][cfs]
0.00 0 0.000 0 0.000 0.00
0.25 1,068 0.025 133 0.003 0.03
0.50 2,136 0.049 534 0.012 0.04
0.75 3,204 0.074 1,201 0.028 0.05
1.00 4,863 0.112 2,210 0.051 0.08
1.25 6,522 0.150 3,633 0.083 0.11
1.50 8,181 0.188 5,471 0.126 0.12
1.75 9,840 0.226 7,724 0.177 0.14
2.00 10,728 0.246 10,295 0.236 0.18
2.25 11,616 0.267 13,088 0.300 0.21
2.50 12,504 0.287 16,103 0.370 0.23
2.75 13,392 0.307 19,340 0.444 0.25
2.76 13,418 0.308 19,474 0.447 0.25
3.02 14,083 0.323 23,049 0.529 2.10
3.01 14,057 0.323 22,908 0.526 1.99
3.26 14,696 0.337 26,502 0.608 5.82
3.51 15,335 0.352 30,256 0.695 11.70
3.76 15,976 0.367 34,170 0.784 19.76
4.01 16,668 0.383 38,250 0.878 30.15
4.26 17,360 0.399 42,504 0.976 42.41
4.51 18,052 0.414 46,930 1.077 47.33
4.76 18,750 0.430 51,530 1.183 48.78
5.01 19,578 0.449 56,321 1.293 50.19
5.26 20,407 0.468 61,319 1.408 51.57
5.51 21,235 0.487 66,524 1.527 52.90
5.76 22,067 0.507 71,937 1.651 54.21
6.01 22,976 0.527 77,567 1.781 55.48
6.26 23,884 0.548 83,425 1.915 56.73
6.51 24,792 0.569 89,509 2.055 57.94
6.76 25,665 0.589 95,564 2.194 59.09
For best results, include the
stages of all grade slope
changes (e.g. ISV and Floor)
from the S-A-V table on
Sheet 'Basin'.
Also include the inverts of all
outlets (e.g. vertical orifice,
overflow grate, and spillway,
where applicable).
5024 -OVERFLOW SPILLWAY
DETENTION BASIN OUTLET STRUCTURE DESIGN
Stage - Storage
Description
5019.25
MHFD-Detention, Version 4.06 (July 2022)
5022.01 WQ - Overflow Weir
Pond 366 MHFD-Detention_v4-06.xlsm, Outlet Structure 12/6/2024, 11:14 AM
Project:
Chamber Model - MC-7200
Units -Imperial
Number of Chambers -82
Number of End Caps -14
Voids in the stone (porosity) - 40 %
Base of Stone Elevation -0.00 ft
Amount of Stone Above Chambers - 12 in
Amount of Stone Below Chambers -9 in
Area of system -5651 sf Min. Area -
Height of
System
Incremental Single
Chamber
Incremental
Single End Cap
Incremental
Chambers
Incremental
End Cap
Incremental
Stone
Incremental Ch,
EC and Stone
Cumulative
System Elevation
(inches)(cubic feet)(cubic feet)(cubic feet)(cubic feet)(cubic feet)(cubic feet)(cubic feet)(feet)
81 0.00 0.00 0.00 0.00 188.37 188.37 24244.25 6.75
80 0.00 0.00 0.00 0.00 188.37 188.37 24055.88 6.67
79 0.00 0.00 0.00 0.00 188.37 188.37 23867.52 6.58
78 0.00 0.00 0.00 0.00 188.37 188.37 23679.15 6.50
77 0.00 0.00 0.00 0.00 188.37 188.37 23490.78 6.42
76 0.00 0.00 0.00 0.00 188.37 188.37 23302.42 6.33
75 0.00 0.00 0.00 0.00 188.37 188.37 23114.05 6.25 #VALUE!
74 0.00 0.00 0.00 0.00 188.37 188.37 22925.68 6.17 #VALUE!
73 0.00 0.00 0.00 0.00 188.37 188.37 22737.32 6.08 Volume between elevations and =
72 0.00 0.00 0.00 0.00 188.37 188.37 22548.95 6.00 #VALUE!
71 0.00 0.00 0.00 0.00 188.37 188.37 22360.58 5.92 #VALUE!
70 0.00 0.00 0.00 0.00 188.37 188.37 22172.22 5.83 WQ Volume achieved at elevation
69 0.06 0.01 4.87 0.18 186.35 191.40 21983.85 5.75
68 0.19 0.03 15.59 0.47 181.94 198.01 21792.45 5.67
67 0.28 0.05 22.56 0.72 179.05 202.34 21594.44 5.58
66 0.36 0.07 29.29 0.92 176.28 206.50 21392.10 5.50
65 0.46 0.08 37.59 1.16 172.87 211.62 21185.61 5.42
64 0.74 0.11 60.81 1.47 163.45 225.74 20973.99 5.33
63 1.10 0.13 89.90 1.85 151.66 243.42 20748.25 5.25
62 1.32 0.16 108.12 2.25 144.22 254.59 20504.83 5.17
61 1.50 0.19 122.86 2.64 138.17 263.66 20250.24 5.08
60 1.65 0.22 135.67 3.06 132.88 271.60 19986.57 5.00
59 1.79 0.25 147.11 3.46 128.14 278.70 19714.97 4.92
58 1.92 0.28 157.41 3.85 123.86 285.13 19436.27 4.83
57 2.04 0.30 167.07 4.23 119.85 291.14 19151.14 4.75
56 2.15 0.33 175.92 4.59 116.17 296.67 18860.00 4.67
55 2.25 0.35 184.31 4.96 112.66 301.93 18563.33 4.58
54 2.34 0.38 192.14 5.37 109.36 306.87 18261.40 4.50
53 2.43 0.41 199.54 5.73 106.26 311.53 17954.53 4.42
52 2.52 0.44 206.56 6.17 103.27 316.01 17643.00 4.33
51 2.60 0.47 213.25 6.56 100.44 320.25 17326.99 4.25
50 2.68 0.50 219.63 6.93 97.74 324.30 17006.74 4.17
49 2.75 0.52 225.71 7.29 95.17 328.17 16682.43 4.08
48 2.82 0.54 231.52 7.62 92.71 331.85 16354.26 4.00
47 2.89 0.57 237.10 7.93 90.35 335.38 16022.41 3.92
46 2.96 0.59 242.42 8.24 88.10 338.76 15687.03 3.83
45 3.02 0.61 247.54 8.54 85.93 342.01 15348.26 3.75
44 3.08 0.63 252.45 8.85 83.85 345.15 15006.25 3.67
43 3.14 0.64 257.17 9.00 81.90 348.07 14661.10 3.58
42 3.19 0.68 261.73 9.48 79.88 351.09 14313.03 3.50
41 3.25 0.70 266.09 9.80 78.01 353.90 13961.94 3.42
40 3.30 0.72 270.30 10.11 76.20 356.61 13608.04 3.33
39 3.35 0.74 274.34 10.41 74.47 359.22 13251.42 3.25
38 3.39 0.76 278.24 10.70 72.79 361.73 12892.21 3.17
37 3.44 0.79 281.99 11.00 71.17 364.16 12530.48 3.08
36 3.48 0.80 285.60 11.24 69.63 366.47 12166.32 3.00
35 3.53 0.82 289.08 11.48 68.14 368.70 11799.85 2.92
34 3.57 0.84 292.43 11.74 66.70 370.87 11431.15 2.83
33 3.61 0.85 295.66 11.92 65.34 372.91 11060.29 2.75
32 3.64 0.86 298.77 12.03 64.05 374.85 10687.37 2.67
31 3.68 0.89 301.76 12.45 62.68 376.89 10312.53 2.58
30 3.71 0.90 304.63 12.66 61.45 378.74 9935.64 2.50
29 3.75 0.92 307.39 12.84 60.27 380.51 9556.90 2.42
28 3.78 0.92 310.04 12.88 59.20 382.12 9176.39 2.33
27 3.81 0.94 312.59 13.21 58.05 383.84 8794.27 2.25
26 3.84 0.96 315.02 13.39 57.00 385.41 8410.43 2.17
25 3.87 0.97 317.35 13.56 56.00 386.92 8025.02 2.08
24 3.90 0.98 319.59 13.74 55.04 388.36 7638.10 2.00
23 3.92 0.97 321.72 13.60 54.24 389.56 7249.74 1.92
22 3.95 1.00 323.76 14.05 53.25 391.05 6860.18 1.83
21 3.97 1.01 325.70 14.16 52.42 392.28 6469.13 1.75
20 3.99 1.02 327.55 14.29 51.63 393.47 6076.85 1.67
19 4.02 1.03 329.31 14.42 50.87 394.61 5683.38 1.58
18 4.04 1.04 330.97 14.54 50.16 395.67 5288.78 1.50
17 4.06 1.05 332.54 14.65 49.49 396.68 4893.10 1.42
16 4.07 1.05 334.03 14.76 48.85 397.64 4496.42 1.33
15 4.09 1.05 335.42 14.71 48.32 398.44 4098.78 1.25
14 4.11 1.06 336.75 14.79 47.75 399.29 3700.34 1.17
13 4.12 1.08 338.01 15.06 47.14 400.21 3301.05 1.08
12 4.14 1.08 339.20 15.16 46.62 400.98 2900.84 1.00
11 4.15 1.09 340.30 15.23 46.15 401.69 2499.86 0.92
10 4.17 1.11 342.02 15.49 45.36 402.87 2098.17 0.83
9 0.00 0.00 0.00 0.00 188.37 188.37 1695.30 0.75
8 0.00 0.00 0.00 0.00 188.37 188.37 1506.93 0.67
7 0.00 0.00 0.00 0.00 188.37 188.37 1318.57 0.58
6 0.00 0.00 0.00 0.00 188.37 188.37 1130.20 0.50
5 0.00 0.00 0.00 0.00 188.37 188.37 941.83 0.42
4 0.00 0.00 0.00 0.00 188.37 188.37 753.47 0.33
3 0.00 0.00 0.00 0.00 188.37 188.37 565.10 0.25
2 0.00 0.00 0.00 0.00 188.37 188.37 376.73 0.17
1 0.00 0.00 0.00 0.00 188.37 188.37 188.37 0.08
REV0 College_Trilby (S442099) 12-06-24
5384 sf min. area
StormTech MC-7200 Cumulative Storage Volumes
Include Perimeter Stone in Calculations
Click Here for Metric
Click for Stage Area Data
Click to Invert Stage Area Data
A B C D E F G H I J K L M N
VAULT
ID
TOTAL
REQUIRED
WQCV
(CF)
WQ FLOW
(CFS)CHAMBER TYPE
RELEASE RATE/
CHAMBER
(CFS)
CHAMBER
VOLUME
(CF)
CHAMBER
VOLUME +
AGGREGATE
(CF)
NUMBER OF
CHAMBERS
RELEASE RATE
WQCV
METHOD
(CFS)
REQUIRED
STORAGE
VOLUME
(CF)
NUMBER OF
CHAMBERS
(FAA)
VOLUME
(CHAMBERS
ONLY)
(CF)
RELEASE
RATE FAA
METHOD
(CFS)
TOTAL
NUMBER OF
CHAMBERS
REQUIRED
TOTAL
SYSTEM
VOLUME
(CF)
WQ A 15,651.83 12.35 MC-7200 0.043 175.9 267.3 59 2.53 14,325 82 14,424 3.51
CONFIRM CONFIRM
A MHFD Extended Detention Basin Spreadsheet WQCV
B 1/2 of the 2-year developed flow rate for the basin being sized
C Chamber type based on site constraints
D Flow rate thru the bottom of the isolator row chamber which is equal to the area of the bottom of the chamber multiplied by the flow rate per unit area (see calculations below)
E Volume within chamber only, not accounting for void spaces in surrounding aggregate (standard spec)
F Volume includes chamber and void space (40%) in surrounding aggregate , per chamber unit. (standard spec)
G Number of chambers required to provide full WQCV within total installed system, include aggregate = A / F
H Release rate per chamber times number of chambers = D * G
I FAA calc based on Flow, WQ and Total Release Rate
J Number of chambers required to provide required FAA staorage volume stored within the chamber only (no aggregate stone) = I / E
K Volume provided in chambers only (no aggregate storage). This must meet or exceed the required FAA storage volume. Greater of G or J * E
L Release rate per chamber times number of chambers = D * J
M Total number of chambers (Greater of J or G)
N Total system volume. Includes number of chambers plus aggregate. This must meet or exceed required WQCV
MC-7200
60.0 60.0 45.0 30.0 16.0 12.0 HEIGHT (IN)5
100.0 100.0 77.0 51.0 34.0 25.0 WIDTH (IN)8.3333333
79.1 48.3 86.0 85.4 85.4 85.4 INSTALLED LENGTH (IN)6.5916667
54.9 33.5 46.0 30.2 20.2 14.8 FLOOR AREA (SF)54.9
175.9 106.5 109.9 45.9 14.7 6.9 CHAMBER VOLUME (CF)175.9
267.3 162.6 175.0 74.9 31.0 15.0 CHAMBER/AGGREGATE VOLUME (CF)267.3
CHAMBER FLOW RATE CONVERSION (GPM/SF TO CFS)
0.35 GPM/SF
1 CF =7.48052 GAL
1 GALLON =0.133681 CF
1 GPM =0.002228 CFS
*FLOW RATE BASED ON 1/2 OF NOV 07 QMAX IN FIGURE 17 OF UNH TESTING REPORT
MC-7200 MC-4500 MC-3500 SC-740 SC-310 SC-160LP
0.043 0.026 0.036 0.024 0.016 0.012 (COLUMN D)FLOW RATE / CHAMBER (CFS)
STORMTECH CHAMBER VOLUME AND RELEASE RATE CALCULATIONS
FLOOR AREA (SF)
CHAMBER VOLUME (CF)
CHAMBER/AGGREGATE VOLUME (CF)
FLOW RATE*
CHAMBER FLOW RATE
WIDTH (IN)
INSTALLED LENGTH (IN)
HEIGHT (IN)
STORMTECH CHAMBER DATA
Subdivision:College and Trilby Project Name:College and Trilby
Location:Fort Collins Project No.:39823.00
Calculated By:ARJ
Checked By:0
Date:11/5/24
WQ Storm
Composite 'C'0.64 ft3 acre-ft.
Area 24.68 Modified Modified 14325.0 0.329
Release Rate 2.53 M. FATER D. JUDISH C. Li
May-95 Apr-98 Nov-98
DETENTION POND SIZING
TIME TIME INTENSITY Q 2 Runoff Release Required Required
cum 1/2 of 2 year Volume Cum total Detention Detention
(mins)(secs)(in/hr)(cfs)(ft^3)(ft^3)(ft^3)(ac-ft)
0 0 0 0.00 0 0.0 0.0 0.0000
5 300 1.425 22.51 6752.448 759.0 5993.4 0.1376
10 600 1.105 17.45 10472.22 1518.0 8954.2 0.2056
15 900 0.935 14.77 13291.66 2277.0 11014.7 0.2529
20 1200 0.805 12.72 15258.16 3036.0 12222.2 0.2806
25 1500 0.715 11.29 16940.35 3795.0 13145.4 0.3018
30 1800 0.650 10.27 18480.38 4554.0 13926.4 0.3197
35 2100 0.585 9.24 19404.4 5313.0 14091.4 0.3235
40 2400 0.535 8.45 20281.04 6072.0 14209.0 0.3262
45 2700 0.495 7.82 21110.28 6831.0 14279.3 0.3278
50 3000 0.460 7.27 21797.38 7590.0 14207.4 0.3262
55 3300 0.435 6.87 22674.01 8349.0 14325.0 0.3289
60 3600 0.410 6.48 23313.72 9108.0 14205.7 0.3261
65 3900 0.385 6.08 23716.49 9867.0 13849.5 0.3179
70 4200 0.365 5.77 24214.04 10626.0 13588.0 0.3119
75 4500 0.345 5.45 24522.05 11385.0 13137.0 0.3016
80 4800 0.330 5.21 25019.6 12144.0 12875.6 0.2956
85 5100 0.315 4.98 25374.99 12903.0 12472.0 0.2863
90 5400 0.305 4.82 26014.69 13662.0 12352.7 0.2836
95 5700 0.290 4.58 26109.47 14421.0 11688.5 0.2683
100 6000 0.280 4.42 26535.94 15180.0 11355.9 0.2607
105 6300 0.270 4.26 26867.64 15939.0 10928.6 0.2509
110 6600 0.260 4.11 27104.56 16698.0 10406.6 0.2389
115 6900 0.255 4.03 27791.65 17457.0 10334.7 0.2373
120 7200 0.245 3.87 27862.73 18216.0 9646.7 0.2215
Required detention
WQ Pond Tributary Areas
SC-160 25 84.4 12 14.65 6.9 15 0.35 0.0007798 0.011
SC-310 34 85.4 16 20.16 14.7 31 0.35 0.0007798 0.016
SC-740 51 85.4 30 30.25 45.9 74 0.35 0.0007798 0.024
DC-780 51 85.4 30 30.25 46.2 78.4 0.35 0.0007798 0.024
MC-3500 77 90 45 48.13 109.9 46.9 0.35 0.0007798 0.038
* Flow Rate given by City of Fort Collins based on UNH Testing Report
Using Highlighted row
Chamber & Aggregate Volume (cf)Flow Rate*
(gpm/sf)
Flow Rate
(cfs/sf)
Flow Rate per Chamber
(cfs)Chamber Type Width
(in)
Length
(in)
Height
(in)
Floor Area
(sf)Chamber Volume (cf)
This document was created by an application that isn't licensed to use novaPDF.
Purchase a license to generate PDF files without this notice.
Using this
College & Trilby Multi-Family Community
Final Drainage Report
APPENDIX E – REFERENCES
LEGEND
EFFECTIVE SWMM DRAINAGE
BASIN DIVIDE LINE
DIRECTION OF FLOW
SUBBASIN
CONVEYANCE ELEMENT - PIPE
DETENTION POND
NODE
CONVEYANCE ELEMENT - SURFACE FLOW
CONVEYANCE ELEMENT - ORIFICE
CONVEYANCE ELEMENT
PORTION OF THE STONE CREEK
EFFECTIVE SWMM SCHEMATIC
3-25-22
8
LEGEND
CORRECTED EFFECTIVE SWMM DRAINAGE
BASIN DIVIDE LINE
(WITH DIRECTION OF FLOW)
SUBBASIN
CONVEYANCE ELEMENT - PIPE
DETENTION POND
NODE
CONVEYANCE ELEMENT - SURFACE FLOW
CONVEYANCE ELEMENT - ORIFICE
CORRECTED CONVEYANCE ELEMENT
EFFECTIVE SWMM DRAINAGE
BASIN DIVIDE LINE
CONVEYANCE ELEMENT
CORRECTED EFFECTIVE SUBBASIN
CORRECTED CONVEYANCE ELEMENT - PIPE
CORRECTED CONVEYANCE ELEMENT - SURFACE FLOW
CORRECTED CONVEYANCE ELEMENT - ORIFICE
CORRECTED EFFECTIVE NODE
CORRECTED EFFECTIVE DETENTION POND
PORTION OF STONE CREEK
CORRECTED EFFECTIVE SWMM SCHEMATIC
2-6-24
(WITH DIRECTION OF FLOW)
10
LEGEND
PROPOSED SWMM DRAINAGE
BASIN DIVIDE LINE
SUBBASIN
CONVEYANCE ELEMENT - PIPE
DETENTION POND
NODE
CONVEYANCE ELEMENT - SURFACE FLOW
CONVEYANCE ELEMENT - ORIFICE
PROPOSED CONVEYANCE ELEMENT
EFFECTIVE SWMM DRAINAGE
BASIN DIVIDE LINE
(WITH DIRECTION OF FLOW)
CONVEYANCE ELEMENT
PROPOSED SUBBASIN
PROPOSED CONVEYANCE ELEMENT - PIPE
PROPOSED CONVEYANCE ELEMENT - SURFACE FLOW
PROPOSED CONVEYANCE ELEMENT - ORIFICE
PROPOSED NODE
PROPOSED DETENTION POND
PORTION OF STONE CREEK
PROPOSED CONDTIONS SWMM SCHEMATIC
2-6-24
(WITH DIRECTION OF FLOW)
12
PROPOSED SWMM DRAINAGE
BASIN DIVIDE LINE
PROPOSED DIRECTION OF FLOW
SUBBASIN
CONVEYANCE ELEMENT - PIPE
DETENTION POND
NODE
CONVEYANCE ELEMENT - SURFACE FLOW
CONVEYANCE ELEMENT - ORIFICE
PROPOSED CONVEYANCE ELEMENT
EFFECTIVE SWMM DRAINAGE
BASIN DIVIDE LINE
DIRECTION OF FLOW
CONVEYANCE ELEMENT
PROPOSED SUBBASIN
PROPOSED CONVEYANCE ELEMENT - PIPE
PROPOSED CONVEYANCE ELEMENT - SURFACE FLOW
PROPOSED CONVEYANCE ELEMENT - ORIFICE
PROPOSED NODE
LEGEND
PROPOSED DETENTION POND
STONE CREEK
PROPOSED CONDTIONS SWMM SCHEMATIC
AREA OF COLLEGE AND TRILBY
INTERSECTION ENHANCEMENTS STORM SYSTEM
2-6-24
13
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E. TRILBY ROAD
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RICK DRIVE
NCOLLEGE AND TRILBY
INTERSECTION ENHANCEMENTS
STORM SYSTEM LAYOUT
9-1-23
0
SCALE: 1" =60'
60 6030 120
C3415
Portion of West Trilby Currently
untreated. Treated within the onsite
Pond P366 as basin OS2
Portion of West Trilby Currently
untreated. Treated within the onsite
Pond P366 as basin OS4. Runoff
rom basin OS3 Drains onto site
T
T
ST
M
ST
M
A1
A2
A3
A4 A5 A6
A7
A8 A9
B1 B2 B3
acres
A1
0.83
1.00 0.09
acres
A2
0.71
0.89 0.39
acres
A3
0.29
0.37 0.52
acres
A4
0.81
1.00 0.24
acres
A5
0.86
1.00 0.48
acres
A6
0.64
0.80 0.86
acres
A7
0.83
1.00 0.18
acres
A8
0.95
1.00 0.34 acres
A9
0.95
1.00 0.34
acres
B1
0.37
0.46 0.14
acres
B3
0.62
0.78 0.01
acres
B2
0.30
0.38 0.20
acres
OS1
0.25
0.31 1.55
-
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STAMP
Date:
Drawn By:
Project No:
Checked By:
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THESE PLANS ARE AN INSTRUMENT OF SERVICE
AND ARE THE PROPERTY OF GALLOWAY, AND MAY
NOT BE DUPLICATED, DISCLOSED, OR REPRODUCED
WITHOUT THE WRITTEN CONSENT OF GALLOWAY.
COPYRIGHTS AND INFRINGEMENTS WILL BE
ENFORCED AND PROSECUTED.
COPYRIGHT
GallowayUS.com
5265 Ronald Reagan Blvd., Suite 210
Johnstown, CO 80534
970.800.3300
PRE
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09.09.2020
GNK000008
JEP
DBC
CAUTION - NOTICE TO CONTRACTOR
1.ALL UTILITY LOCATIONS SHOWN ARE BASED ON MAPS
PROVIDED BY THE APPROPRIATE UTILITY COMPANY AND
FIELD SURFACE EVIDENCE AT THE TIME OF SURVEY AND IS TO
BE CONSIDERED AN APPROXIMATE LOCATION ONLY. IT IS THE
CONTRACTOR'S RESPONSIBILITY TO FIELD VERIFY THE FIELD
LOCATION OF ALL UTILITIES, PUBLIC OR PRIVATE, WHETHER
SHOWN ON THE PLANS OR NOT, PRIOR TO CONSTRUCTION.
REPORT ANY DISCREPANCIES TO THE ENGINEERED PRIOR TO
CONSTRUCTION.
2.WHERE A PROPOSED UTILITY CROSSES AN EXISTING UTILITY,
IT IS THE CONTRACTOR'S RESPONSIBILITY TO FIELD VERIFY
THE HORIZONTAL AND VERTICAL LOCATION OF SUCH
EXISTING UTILITY, EITHER THROUGH POTHOLING OR
ALTERNATIVE METHOD. REPORT INFORMATION TO THE
ENGINEER PRIOR TO CONSTRUCTION.
3.CONTRACTOR RESPONSIBLE FOR AS-BUILT DRAWINGS,
TESTS, REPORTS AND/OR ANY OTHER CERTIFICATES OR
INFORMATION AS REQUIRED FOR ACCEPTANCE OF WORK
FROM CITY, UTILITY DISTRICTS OR ANY OTHER GOVERNING
AGENCY.
4.CONTRACTOR SHALL PROTECT ALL EXISTING SURVEY
MONUMENTATION. CONTRACTOR SHALL HAVE LICENSED
SURVEYOR REPLACE ANY DAMAGED OR DISTURBED
MONUMENTATION AT THEIR COST.
Know what's
before you dig.
DRAINAGE PLAN
C8.0
SCALE: 1"=30'
0 15 30
LEGEND:
PROPOSED STORM SEWER
EXISTING STORM SEWER
PROPOSED STORM INLET
PROPOSED LOTLINE
EASEMENT LINE
EXISTING MINOR CONTOUR
EXISTING MAJOR CONTOUR
PROPOSED MINOR CONTOUR
PROPOSED MAJOR CONTOUR
PROPERTY BOUNDARY
EXISTING MANHOLE
DRAINAGE SYMBOLS:
DESIGN POINT
MAJOR BASIN BOUNDARY (i.e., C-STORE)
SUB-BASIN BOUNDARY (i.e., RATIONAL METHOD)
OVERLAND FLOW DIRECTION
(I.E., LANDSCAPING)
DIRECT FLOW DIRECTION
(I.E., PAVEMENT, CURB AND
GUTTER)
BASIN ID
MINOR (2YEAR) RUNOFF
COEFFICIENT
MAJOR (100YEAR) RUNOFF
COEFFICIENT
BASIN AREA
(ACRES)
acres
A1
0.23
0.45
1.00
A1
HIGH POINT
TRILBY ROAD TRILBY ROAD
CO
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SKYWAY DRIVE
CO
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NORTH TRIBUTARY
MIDDL
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HUN
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SOUTH TRIBUTARY
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TRIBUTARY
C1: PROPOSED STORM
SEWER SYSTEM
STON
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D1: FLOODPLAIN REGULATIONS
D2: CROWN RIDGE LANE
CULVERT IMPROVEMENTS
(10'W X 3'H BOX CULVERT)
CROWN RIDGE LANE
PROVINCETOWNE
DEVELOPMENT
RICK DRIVE
A1: FLOODPLAIN DEVELOPMENT
REGULATIONS
A2: OVERFLOW CHANNEL TO POND
363 (RIPRAP LINED CHANNEL)
E1: Ditch Crossing Structure
B1: FLOODPLAIN
DEVELOPMENT REGULATIONS
B2: INCREASED CAPACITY
UNDER COLLEGE AVE
LEMAY AVENUE
CROSSING
IMPROVEMENTS
A
PROBLEM IDENTIFICATION
AREA LOCATIONS
COLLEGE AVENUE APPROXIMATELY
600-FEET NORTH OF TRILBY ROAD
B
COLLEGE AVENUE AT SKYWAY DRIVEC
D
E
SPILL FLOW TO PROVINCETOWNE
LOUDEN DITCH CROSSING
COLLEGE AVENUE 1,500-FEET
NORTH OF TRILBY ROAD
NORTH
0
SCALE : 1" = 300
300 600
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SELECTED PLAN IMPROVEMENTS
PROJECT NO: 17-049-SCBAPPR.REVISIONSNo. DATE
ICON
ENGINEERING, INC.
PREPARED BY:
Know what's below.
Call before you dig.1-1
VERIFY SCALE
0 1"
BAR IS ONE INCH
ON ORIGINAL
DRAWINGS
SEPT 2018
PREPARED FOR:
5000
50
0
0
501
0
50
0
0
50
0
5
0+00
1+00
2+00 3+00 4+00 5+00 6+00 7+00
EXISTING 30" RCP TO BE
REPLACED WITH 48" RCP
PROPOSED
MANHOLE
CO
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A
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EXISTING 48" RCP
EXTEND EXISTING 48" RCP
TO COLLEGE AVE LIMITS
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F:
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LOCATION A: OVERFLOW CHANNEL FROM POND 366 TO POND 363
PROJECT NO: 17-049-SCBAPPR.REVISIONSNo. DATE
ICON
ENGINEERING, INC.
PREPARED BY:
Know what's below.
Call before you dig.1 OF 1
VERIFY SCALE
0 1"
BAR IS ONE INCH
ON ORIGINAL
DRAWINGS
SEPT 2018
PREPARED FOR:
NOT FOR CONSTRUCTION
Conceptual Design.
See JR design within
Appendix F section
CC in the Proposed
Drainage Map.
ST ST
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LOCATION B: INCREASED CAPACITY UNDER COLLEGE AVENUE
PROJECT NO: 17-049-SCBAPPR.REVISIONSNo. DATE
ICON
ENGINEERING, INC.
PREPARED BY:
Know what's below.
Call before you dig.
PREPARED FOR:
1 OF 1
VERIFY SCALE
0 1"
BAR IS ONE INCH
ON ORIGINAL
DRAWINGS
SEPT 2018
PLAN AND PROFILE
NOTES:
NORTH
0
SCALE : 1" = 100'
100 200
400 North Link Lane | Fort Collins, Colorado 80524
Telephone: 970-206-9455 Fax: 970-206-9441
April 24, 2024
Zocalo Community Development
455 Sherman Street, Suite 205
Denver, Colorado 80203
Attention:
Subject:Supplementary Groundwater Monitoring
Core Spaces
Fort Collins, Colorado
CTL|T Project Number: FC10864-112
CTL|Thompson, Inc. is performing a groundwater monitoring study at the above
referenced project. This letter presents the most recent groundwater measurements from
piezometers at the site.
On June 19th through 26th, 2023, twelve borings were drilled at the locations shown on
Figure 1 (TH-1 through TH-12) using solid-stem augers and a truck-mounted drill rig. The
monitoring holes were fitted with temporary PVC piezometers to facilitate monthly groundwater
measurements. Groundwater was measured relative to the existing ground surface by a
representative from our firm. The table below summarizes our groundwater measurements to
date.
We appreciate the opportunity to work with you on this project. If you have any
additional questions or concerns, please contact the undersigned.
Sincerely,
CTL|THOMPSON, INC.
Jesus Martinez , PE
Staff Geotechnical Technician Senior Engineer
04.24.2024
ZOCALO COMMUNITY DEVELOPMENT
CORE SPACES
CTL | T PROJECT NO. FC10864-112
2
ZO
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College & Trilby Multi-Family Community
Final Drainage Report
APPENDIX F – MAPS
A
W
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s
t
r
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a
n
C
o
m
p
a
n
y
WEST TRILBY ROAD
SO
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T
Know what's below.
before you dig.Call
R
WEST TRILBY ROAD
SO
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L
L
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G
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A
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SO
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C
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U
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T
LEGEND
EFFECTIVE SWMM DRAINAGE
BASIN DIVIDE LINE
(WITH DIRECTION OF FLOW)
CONVEYANCE ELEMENT
PROPOSED SWMM DRAINAGE
BASIN DIVIDE LINE
CIP PROPOSED CONVEYANCE ELEMENT
(WITH DIRECTION OF FLOW)
SUBBASIN
CIP SUBBASIN
CONVEYANCE ELEMENT - PIPE
CIP PROPOSED CONVEYANCE ELEMENT - PIPE
CONVEYANCE ELEMENT - SURFACE FLOW
CIP PROPOSED CONVEYANCE ELEMENT - SURFACE FLOW
CONVEYANCE ELEMENT - ORIFICE
CIP PROPOSED CONVEYANCE ELEMENT - ORIFICE
DETENTION POND
CIP PROPOSED DETENTION POND
NODE
CIP PROPOSED NODE
A
W
e
s
t
r
i
a
n
C
o
m
p
a
n
y
WEST TRILBY ROAD
SO
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A
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N
U
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SO
L
A
R
C
O
U
R
T
Know what's below.
before you dig.Call
R
LEGEND
EFFECTIVE SWMM DRAINAGE
BASIN DIVIDE LINE
(WITH DIRECTION OF FLOW)
CONVEYANCE ELEMENT
PROPOSED SWMM DRAINAGE
BASIN DIVIDE LINE
CIP PROPOSED CONVEYANCE ELEMENT
(WITH DIRECTION OF FLOW)
SUBBASIN
CIP SUBBASIN
CONVEYANCE ELEMENT - PIPE
CIP PROPOSED CONVEYANCE ELEMENT - PIPE
CONVEYANCE ELEMENT - SURFACE FLOW
CIP PROPOSED CONVEYANCE ELEMENT - SURFACE FLOW
CONVEYANCE ELEMENT - ORIFICE
CIP PROPOSED CONVEYANCE ELEMENT - ORIFICE
DETENTION POND
CIP PROPOSED DETENTION POND
NODE
CIP PROPOSED NODE
A
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R
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SEE SHEET 23
SEE SHEET 24
A
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WEST TRILBY ROAD
SO
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before you dig.Call
R
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A Westrian Company
ONSITE BASIN LENGTHS - SWMM MAP
COLLEGE & TRILBY MULTI-FAMILY COMMUNITY
Altitud
e
:
0
.
0
0
0
0
_
_
_
_
_
_
_
_
_
Name: C
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_
_
_
_
_
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_
_
_
_
_
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_
Longitu
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:
-
1
0
5
.
0
7
6
8
6
9
7
9
0
8
1
2
0
0
Latitud
e
:
4
0
.
4
9
4
5
6
2
4
2
7
4
7
3
3
3
_
_
LEGEND
(WITH DIRECTION OF FLOW)
CONVEYANCE ELEMENT
CIP SWMM DRAINAGE
BASIN DIVIDE LINE
CIP PROPOSED CONVEYANCE ELEMENT
(WITH DIRECTION OF FLOW)
SUBBASIN
CIP SUBBASIN
CONVEYANCE ELEMENT - PIPE
CONVEYANCE ELEMENT - SURFACE FLOW
CIP PROPOSED CONVEYANCE ELEMENT - SURFACE FLOW
CONVEYANCE ELEMENT - ORIFICE
CIP PROPOSED CONVEYANCE ELEMENT - ORIFICE
DETENTION POND
CIP PROPOSED DETENTION POND
NODE
CIP PROPOSED NODE
JR MODIFIED BASIN
BASIN DIVIDE LINE
JR PROPOSED NODE
JR MODIFIED SWMM DRAINAGE
JR PROPOSED DETENTION / WQ POND
JR PROPOSED CONVEYANCE ELEMENT - ORIFICE
JR PROPOSED RATING CURVE
JR PROPOSED CONVEYANCE ELEMENT
(WITH DIRECTION OF FLOW)
CIP PROPOSED CONVEYANCE ELEMENT - PIPE
JR PROPOSED BASIN LENGTH
A Westrian Company
COLLEGE & TRILBY MULTI-FAMILY COMMUNITY
#
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PROPOSED SWMM MAP
Altitud
e
:
0
.
0
0
0
0
_
_
_
_
_
_
_
_
_
Name: C
o
l
l
e
g
e
_
T
r
i
l
b
y
_
G
E
_
_
_
_
_
_
_
_
_
_
_
_
_
_
_
_
_
Longitu
d
e
:
-
1
0
5
.
0
7
6
8
6
9
7
9
0
8
1
2
0
0
Latitud
e
:
4
0
.
4
9
4
5
6
2
4
2
7
4
7
3
3
3
_
_
LEGEND
(WITH DIRECTION OF FLOW)
CONVEYANCE ELEMENT
CIP SWMM DRAINAGE
BASIN DIVIDE LINE
CIP PROPOSED CONVEYANCE ELEMENT
(WITH DIRECTION OF FLOW)
SUBBASIN
CIP SUBBASIN
CONVEYANCE ELEMENT - PIPE
CONVEYANCE ELEMENT - SURFACE FLOW
CIP PROPOSED CONVEYANCE ELEMENT - SURFACE FLOW
CONVEYANCE ELEMENT - ORIFICE
CIP PROPOSED CONVEYANCE ELEMENT - ORIFICE
DETENTION POND
CIP PROPOSED DETENTION POND
NODE
CIP PROPOSED NODE
JR MODIFIED BASIN
BASIN DIVIDE LINE
JR PROPOSED NODE
JR MODIFIED SWMM DRAINAGE
JR PROPOSED DETENTION / WQ POND
JR PROPOSED CONVEYANCE ELEMENT - ORIFICE
JR PROPOSED RATING CURVE
JR PROPOSED CONVEYANCE ELEMENT
(WITH DIRECTION OF FLOW)
CIP PROPOSED CONVEYANCE ELEMENT - PIPE
A Westrian Company
TRILBY / COLLEGE
EX-DRAINAGE EXHIBT
College & Trilby Multi-Family Community
Final Drainage Report
APPENDIX G –LID EXHIBIT
WEST TRILBY ROAD
SO
U
T
H
C
O
L
L
E
G
E
A
V
E
N
U
E
SO
L
A
R
C
O
U
R
T
A
W
e
s
t
r
i
a
n
C
o
m
p
a
n
y
Know what's below.
before you dig.Call
R
VA
U
L
T
VA
U
L
T
VA
U
L
T
VA
U
L
T
VA
U
L
T
VA
U
L
T
VA
U
L
T
VA
U
L
T
VA
U
L
T
VA
U
L
T
M
M
M
M
M
M
M
M
M
M
M
M
M
M
M
M
M
M
M
M
M
M
M
M
M
M
M
M
M
M
M
M
M
M
M
M
M
VA
U
L
T
M
M
M
M
M
M
M
M
M
VA
U
L
T
VA
U
L
T
VA
U
L
T
M
M
M
M
VAULT
AA
B B
GA
L
A
C
T
I
C
L
A
N
E
GA
L
A
C
T
I
C
L
A
N
E
RO
V
E
R
W
A
Y
MA
R
S
D
R
I
V
E
MO
O
N
B
E
A
M
W
A
Y
NO
V
A
L
A
N
E
WEST TRILBY ROAD
SO
U
T
H
C
O
L
L
E
G
E
A
V
E
N
U
E
SO
L
A
R
C
O
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R
T
A
W
e
s
t
r
i
a
n
C
o
m
p
a
n
y
VA
U
L
T
VA
U
L
T
VA
U
L
T
VA
U
L
T
VA
U
L
T
VA
U
L
T
M
M
M
M
M
M
M
M
M
M
M
M
M
M
M
M
M
M
M
M
M
M
M
M
M
M
M
M
M
M
VAULT
VAULT
VA
U
L
T
M
M
M
M
M
M
M
B B
C C
RO
V
E
R
W
A
Y
MA
R
S
D
R
I
V
E
NO
V
A
L
A
N
E
NO
V
A
L
A
N
E
LUNAR COURT
MA
R
S
D
R
I
V
E
STELLAR DRIVE
ST
A
R
D
U
S
T
L
A
N
E
MO
O
N
B
E
A
M
W
A
Y
A
W
e
s
t
r
i
a
n
C
o
m
p
a
n
y
Know what's below.
before you dig.Call
R
Altitud
e
:
0
.
0
0
0
0
_
_
_
_
_
_
_
_
_
Name: C
o
l
l
e
g
e
_
T
r
i
l
b
y
_
G
E
_
_
_
_
_
_
_
_
_
_
_
_
_
_
_
_
_
Long
i
t
u
d
e
:
-
1
0
5
.
0
7
6
8
6
9
7
9
0
8
1
2
0
0
Latitud
e
:
4
0
.
4
9
4
5
6
2
4
2
7
4
7
3
3
3
_
_
VA
U
L
T
VA
U
L
T
VA
U
L
T
VA
U
L
T
VA
U
L
T
VA
U
L
T
VAULT
VAULT
VA
U
L
T
MA
R
S
D
R
I
V
E