HomeMy WebLinkAboutCROWNE AT OLD TOWN NORTH (FORMERLY CROWNE ON SUNIGA - RESIDENTIAL) - PDP - PDP170007 - SUBMITTAL DOCUMENTS - ROUND 2 - DRAINAGE REPORTPreliminary Drainage and Erosion Control Report
for
Crowne at Old Town North
Fort Collins, Colorado
April 19, 2017
April 19, 2017
Mr. Wes Lamarque
City of Fort Collins
Water Utilities--Storm water
700 Wood Street
Fort Collins, Colorado 80521
RE: Preliminary Drainage and Erosion Control Report Crowne at Old Town North
Dear Wes:
We are pleased to submit to you, for your review and approval, this Preliminary Drainage and
Erosion Control Report for Crowne at Old Town North. All computations within this report have
been completed in compliance with the City of Fort Collins Storm Drainage Design Criteria.
We appreciate your time and consideration in reviewing this submittal. Please call if you have any
questions.
Respectfully,
Aspen Engineering
John Gooch, P.E.
Principal
TABLE OF CONTENTS
DESCRIPTION PAGE
I. GENERAL LOCATION AND DESCRIPTION 5
A. LOCATION 5
B. DESCRIPTION OF PROPERTY 5
II. DRAINAGE BASINS 6
A. MAJOR BASIN DESCRIPTION 6
B. EXISTING SUB-BASIN DESCRIPTION 7
C. PROPOSED SUB-BASIN DESCRIPTION 7
III. DRAINAGE DESIGN CRITERIA 8
A. REGULATIONS 8
B. DEVELOPMENT CRITERIA REFERENCE AND CONSTRAINTS 8
C. HYDROLOGIC CRITERIA 8
D. HYDRAULIC CRITERIA 8
E. VARIANCES 9
IV. DRAINAGE FACILITY DESIGN 9
A. GENERAL CONCEPT 9
B. SPECIFIC DETAILS 9
C. DETENTION POND 14
D. STREET CAPACITIES 15
V. STORM WATER QUALITY 15
A. GENERAL CONCEPT & SPECIFIC DETAILS 15
VI. EROSION CONTROL 15
A. GENERAL CONCEPT 15
VII. CONCLUSIONS 16
A. COMPLIANCE WITH STANDARDS & STORMWATER 16
OPERATIONS/ MAINTENANCE PROCEDURE
B. DRAINAGE CONCEPT 17
C. STORM WATER QUALITY 17
D. EROSION CONTROL CONCEPT 17
E. EROSION CONTROL ESCROW ESTIMATE 17
REFERENCES 18
APPENDIX
PAGE
VICINITY MAP A
RATIONAL METHOD HYDROLOGY & POND SIZING B
STORM SEWER PIPE SIZING C
INLET & CONCRETE SIDEWALK CULVERT SIZING D
SWALE SIZING E
EROSION CONTROL & RIPRAP SIZING F
PROPOSED AND EXISTING DRAINAGE BASIN EXHIBITS G
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PRELIMINARY DRAINAGE
AND EROSION CONTROL REPORT
FOR CROWNE AT OLD TOWN NORTH
FORT COLLINS, COLORADO
I. GENERAL LOCATION AND DESCRIPTION
A. Location
The Crowne at Old Town North project is located approximately 450 feet east of
North College, along future Suniga Road. The property is bound to the west by a
portion of Dry Creek and Jax Outdoors. The property is bound to the north by
Conifer Street and to the south by future Suniga Road. The Aspen Heights
development bounds the property to the east.
The project site can also be described as situated in the southwest quarter of Section
1, Township 7 North, Range 69 West of the 6th P.M., City of Fort Collins, County of
Larimer, State of Colorado. The site (property boundary) comprises approximately
15.71 acres (see vicinity map Appendix A).
B. Description of Property
The project site currently is an existing 15.71-acre vacant field comprised of
primarily dirt with native weeds and grasses. The site was formerly used as a
materials staging area during the construction of the Aspen Heights development.
Dry Creek runs along the west boundary of the proposed site.
The majority of the existing site (east portion) has topography which generally slopes
from the northwest to the south-southeast at approximately 0.5%, with varying slopes
from 0.3% to 0.8%.
The proposed development consists of 289 apartment units housed in five buildings,
15 townhome units housed in four buildings, a Clubhouse with pool, and associated
street, water, sanitary sewer, storm sewer, and private infrastructure improvements,
as well as intermittent green spaces and outdoor spaces.
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II. DRAINAGE BASINS
A. Major Basin Description
The Crowne at Old Town North project lies within the City of Fort Collins Dry Creek
Drainage Basin. The Dry Creek Drainage Basin generally flows from the northwest to
southeast and ultimately outlets into the Poudre River.
A.1 NECCO Regional Storm Sewer System
In speaking with the City of Fort Collins Stormwater Department, the proposed
development is not required to provide detention or water quality as both water quality
and detention volume for the Crowne site is being provided in the NECCO regional
detention pond. The NECCO regional pond is scheduled to be constructed at the
beginning of 2018.
The development is part of the NECCO Master Plan. NECCO Storm Sewer C1 travels
along the southern boundary of the site, adjacent to Suniga Road. The storm sewer
starts at the NECCO regional pond and heads west as a 66-in reinforced concrete pipe
(RCP). Per the current NECCO materplan, the storm sewer is to transition to a 48-in
storm sewer at the southeast corner of the site. However, per the City Stormwater’s
request, the 66” RCP shall be extended further west and to the first private drive, that
runs north-south, within the southeast corner of the Crowne at Old Town North project.
The 66” RCP will transition down to a 48” RCP at the first private drive and will be
extended west to Crowne’s western property boundary.
It’s important to note that the NECCO masterplan improvements show the 48-in storm
sewer making a 90-degree bend at the southwest corner of the Crowne site and
traveling north along the existing Dry Creek alignment. Per discussions with City
Stormwater, the 48” extension to the north will not be required at this time, as the
intent of the 48” RCP is to serve the developed condition of properties to the west and
not the Crowne site.
Therefore, a storm sewer stub-out will be provided to the north (at Crowne’s southwest
corner) to allow for runoff, from properties to the west and northwest, that flows in the
existing open ditch (along Crowne’s western boundary) to be conveyed into the
NECCO 48” storm system that runs west-to-east along the north side of Suniga Road.
The flows from the attributable, adjacent, existing properties and from the proposed
project site will be conveyed east and into the regional detention pond. The 66-in
storm sewer was constructed with the Aspen Heights development. The extension of
the 66-inch storm sewer and the transition to the 48-in storm sewer will be constructed
with this project, as noted above.
7
The proposed site was broken into four major basins and included into the Dry Creek
master plan model to insure that the proposed design would meet the design intents of
the master plan. Basin Crowne-West represents basins 18-23. These basins will drain
into the 48-in storm sewer at the southwest corner of the property. Basin Crowne-Main
represents the majority of the proposed development (basins 1-17 and OS1). This
basin discharges into the 66-in storm sewer in the southeast quadrant of the site. The
modeling demonstrated that the proposed development can drain into the NECCO
system at both design points. The hydraulic grade line in the 48-in storm sewer is
reduced slightly from the master plan conditions.
The basins draining to Suniga Road were also adjusted in the master plan model as
well as the basins draining to Conifer Street. This was to insure that the minor change
in basin area does not negatively impact the NECCO storm sewer system. These
basins are described in more detailed in sections below.
B. Existing Sub-Basin Description
The existing site consists primarily of dirt with intermittent grasses and weeds. Dry
Creek runs along the west side of the property. The property can be broken into two
main existing drainage basins. The majority of the property consists of one basin
(EX1). The site drains from the northwest corner of the site to the southeast corner of
the site. This drainage continues south to two 14” x 23” HERCP. These culverts
cross under Blue Spruce and ultimately to Dry Creek. A smaller basin (EX2) flows
west to the Dry Creek channel that travels along the west side of the property. It’s
important to note that a small portion of the site (approximately 2.59 acres) from
Aspen Height’s basins OS6 and OS7 was modeled to drain into 5 inlets, located
along the western boundary (bottom west side of retaining walls) of Aspen Heights.
C. Proposed Sub-Basin Description
The proposed development consists of 289 apartment units housed in five buildings,
15 townhome units housed in four buildings, a Clubhouse with pool, and associated
street, water, sanitary sewer, storm sewer, and private infrastructure improvements,
as well as intermittent green spaces and outdoor spaces.
The majority of the runoff from the proposed 15.71+/- acre development will be
routed to the NECCO storm sewer systems located along the south and southwest
boundaries of the proposed site. The NECCO storm sewers will route the flows to
the NECCO regional detention pond. The regional detention pond provides detention
and water quality for the proposed development.
8
The proposed public roads will be paved with asphalt, while the private drives and
adjacent parking areas will be paved in concrete or asphalt. Interior sidewalks will
be paved in concrete to serve pedestrians and provide access throughout the site.
III. DRAINAGE BASIN CRITERIA
A. Regulations
The drainage design for the subject site is required to meet the current City of Fort
Collins Stormwater and Erosion Control Standards and requirements. Therefore, the
drainage design for the subject site has been designed in accordance with these
standards and provides for the site drainage. The proposed project is not required to
provide water quality or on-site detention, as both water quality and detention are
being provided in the NECCO Regional Detention pond. Previous masterplan
modeling, by Ayres Associates, provided for an impervious ratio of 89% for the
Crowne development. The calculated impervious ratio for the Crowne development
(including offsite basins) is 76%.
B. Development Criteria Reference and Constraints
The criteria and constraints from the City of Fort Collins will be met. The proposed
project is being routed to the NECCO storm sewer system. The capacity of the
system was verified in the Dry Creek Master Plan EPA SWMM model.
C. Hydrologic Criteria
The Rational Method for determining surface runoff was used for the project site.
The 2-year and 100-year storm event intensities were used in calculating runoff
values. The City of Fort Collins intensity duration frequency curves were used to
obtain rainfall data for each storm specified.
D. Hydraulic Criteria
All hydraulic calculations within this report have been prepared in accordance with
the City of Fort Collins Drainage Criteria and are also included in the Appendix.
Final storm sewer pipe and inlet/curb cut sizing will be completed during final design
using UDSewer and UDInlet from UDFCD, as well as other orifice/inlet control
sizing spreadsheets. Final Swale sizing will also be completed during final design
using AutoCadd Civil 3D Hydraulic Software, while final erosion control/riprap
sizing will be calculated using North American Green software.
9
E. Variances
No variances are being requested at this time.
IV. DRAINAGE FACILITY DESIGN
A. General Concept
Twenty-eight proposed onsite drainage basins and six offsite basins have been
created to analyze the drainage for the proposed development.
Basins 1-17 and OS1 drain ultimately to the southeast quadrant of the site via
overland flow, curb and gutter, and proposed storm sewer systems. The drainage is
ultimately collected in a proposed storm sewer which will connect into the 66-in
NECCO storm sewer. The 100-year peak flow to the 66-in storm sewer at this
location will be 56.98 cfs.
Basins 18-23 drain to the west side of the property via overland flow, curb and gutter,
and proposed storm sewer system. The basins ultimately drain to the 48-in NECCO
storm sewer located in the southwest corner of the site. The 100-year peak flow to
the 48-in storm sewer is 13.76 cfs.
The NECCO storm sewer drains to the east to the NECCO Regional Detention Pond.
The regional pond is anticipated to be constructed at the beginning of 2018.
The offsite basins OS3-OS6 drain to future Suniga Road. Basin 28 and offsite basins
OS2 drains to Conifer Street. The impacts of these flows to storm sewer systems on
Conifer Street and Suniga Road were verified in Dry Creek master plan EPA SWMM
model.
Please refer to the rational calculations in Appendix B and the Existing and Proposed
Drainage Basin Exhibits in Appendix G for additional information. The inlets and
storm sewer system will be sized with final design.
B. Specific Details
Drainage to the NECCO 66-inch Storm Sewer:
The runoff from the following basins is collected in a storm sewer system which
ultimately connected into the NECCO 66-in storm sewer located in the southeast
quadrant of the site. These basins represent basin Crowne-Main in the Dry Creek
EPA SWMM model. Basin Crowne-Main was modified to determine the impacts of
the proposed development to the NECCO system.
10
It’s important to note that Ayres Associates masterplan modeling provided an
impervious ratio of 89% for the Crowne development area, versus the calculated
impervious ratio of 76% (including offsite, adjacent basins), as seen in the rational
calculations of this report.
The following is the conveyance summary for the onsite and offsite basins for the
Crowne at Old Town North development:
Basin 1
Basin 1 will convey its flow overland to a LID Basin. The runoff is directed
to the LID basin through a curb cut. The LID Basin discharges into a
proposed storm sewer system at design point 1.
Basin 2
Basin 2 drains overland to dual inlets at design points 2. The inlets are
located in the grass strip between the parking lot and building and will drain
to a proposed storm sewer system.
Basin 3
Basin 3 drains via overland flow to a LID basin located at design point 3.
The LID basin is located in the middle of a parking lot median. The runoff is
directed to the LID Basin through two curb cuts. The LID Basin discharges
into the proposed storm sewer system.
Basin 4
Basin 4 drains via overland flow to a LID basin located at design point 4.
The LID basin is located in the middle of a parking lot median. The runoff is
directed to the LID Basin through two curb cuts. The LID Basin discharges
into the proposed storm sewer system.
Basin 5
Basin 5 drains via overland flow to a low spot at design point 5. An inlet is
located at the low spot which will collect the runoff and discharge into the
proposed storm sewer system. The inlet is located in a grassy area to the east
of the building.
Basin 6
Basin 6 drains via overland flow to a low spot at design point 6. Inlets
located in the low spot will collect the runoff and discharge into the proposed
storm sewer system. This basin contains pavers which discharge to the inlets
at design point 6.
Basin 7
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Basin 7 drains via overland flow, curb and gutter, and storm sewer to a low
spot at design point 7. Design point 7 contains inlets that are connected to
the proposed storm sewer system. The inlet at design point 7 is a Type R
curb inlet located along Lupine Drive.
Basin 8
Basin 8 drains via overland flow, curb and gutter, and storm sewer to a low
spot at design point 8. Design point 8 contains inlets that are connected to
the proposed storm sewer system. The inlet at design point 8 is a Type R
curb inlet located along Lupine Drive.
Basin 9
Basin 9 drains to a LID Basin located at design point 9. The LID Basin
connects into the proposed storm sewer system via a proposed inlet. The LID
Basin is located adjacent to a sidewalk in Basin 9.
Basin 10
Basin 10 drains to a low spot at design point 10, in the middle of a parking
lot. An inlet is located at the low spot. This inlet collects runoff from the
basin and conveys it to the proposed storm sewer system. This basin contains
pavers which discharge to the inlets at design point 10.
Basin 11
Basin 11 drains to an inlet at design point 11, which discharges into the
proposed storm sewer system. Drainage from basin 11 flows via overland
flow to a curb cut which directs the flow to the inlet.
Basin 12
Basin 12 drains via overland flow, curb and gutter and storm sewer to design
point 12. Design point 12 consists of a LID Basin with an inlet in the middle
of a parking lot median. This inlet connects into the proposed storm sewer
system.
Basin 13
Basin 13 drains to a low spot at design point 13, in the middle of a parking
lot. An inlet is located at the low spot. This inlet collects runoff from the
basin and conveys it to the proposed storm sewer system. This basin contains
pavers which discharge to the inlets at design point 13.
Basin 14
Basin 14 drains to low spot at design point 14. The inlet at design point 14
collects the runoff from the basin and connects into the proposed storm sewer
system. The inlet is located east of the curb and gutter. Runoff from the
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basin is directed via overland flow and curb cut to the low point. This basin
contains pavers which discharge to the inlets at design point 14.
Basin 15
Basin 15 consists of the area that drains to the east half of Jerome Street.
The runoff from this basin flows via overland flow and curb and gutter to a
low point located at design point 15. The inlet at design point 15 is a Type R
curb inlet located along Jerome Street. The inlet conveys the runoff to the
proposed storm sewer system.
Basin 16
Basin 16 consists of the area that drains to the west half of Jerome Street and
small western portion of Lupine Drive. The runoff from this basin flows via
overland flow and curb and gutter to a low point located at design point 16.
The inlet at design point 16 is a Type R curb inlet located along Jerome
Street. The inlet conveys the runoff to the proposed storm sewer system.
Basin 17
Basin 17 drains to a low spot at design point 17. The low spot is in a grassy
area between a building and the street and contains an inlet. This inlet ties
into the proposed storm sewer system.
Basin 24
Basin 24 is a small 0.03-acre basin that drains to an existing area inlet located
at the southeast corner of the development. The existing inlet will be raised to
match proposed grade of the Crowne Development.
Basins 25 and 26
These basins are a combined area of 0.04-acres and drain to Lupine Drive and
ultimately to Aspen Heights.
Basin 27
Basin 27 is a small 0.11 acre (predominantly green-area) that drains via
overland flow to two existing area inlets, located along the bottom of the
retaining wall, which was constructed with Aspen Heights. The existing
inlets will be raised to match proposed grade of the Crowne Development.
It’s important to note that though the Aspen Heights Drainage Report
provided for and allows approximately 2.59 acres of Crowne’s site to flow to
the existing inlets, only approximately 0.18 acres will be directed to the
existing inlets.
Basin OS1
Basin OS1 consists of the area that drains to the west half of Jerome Street,
north of Lupine Drive. The runoff from this basin flows via overland flow
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and curb and gutter to a low point located at design point 16. The inlet at
design point 16 is a Type R curb inlet located along Jerome Street. The inlet
conveys the runoff to the proposed storm sewer system.
Drainage to the NECCO 48-inch Storm Sewer:
The runoff from the following basins is collected in a storm sewer system which
ultimately connects into the NECCO 48-in storm sewer located along the western
boundary of the site. These basins represent basin Crowne-West in the Dry Creek
EPA SWMM model. Basin Crowne-West was modified to determine the impacts of
the proposed development to the NECCO system.
Basins 18-23
Basins 18-23 drain ultimately to a series of LID basins, located along the west
boundary of the site. Runoff is conveyed to the LID basins via overland flow,
curb and gutter, and curb cuts to the LID Basins. All LID basins will have
underdrain systems that will convey filtered runoff into the 48” NECCO
storm sewer system, via the inlets at design points 19, 21, and 23.
Offsite Drainage
The runoff from the following basins drain offsite.
Basin 28 and OS2
Basin 28 and OS2 represent a portion of the project that drains to the north
and onto Conifer Street. These basins are part of basin 26 in the Dry Creek
EPA SWMM model. Basin 26 was modified to correctly include the runoff
from these basins. This was done to insure that the impacts to the offsite
system were minimal and met the design intent of the NECCO storm sewer
system.
OS3 and OS4
Basins OS3 and OS4 represent a portion of the project that drains to the west
along Suniga Road. These basins are part of basin 316 in the Dry Creek EPA
SWMM model. Basin 316 was modified to correctly include the runoff from
these basins. This was done to insure that the impacts to the offsite system
were minimal and met the design intent of the NECCO storm sewer system.
Should Suniga Road be extended west of the Crowne development by the
City of Fort Collins, basins OS3 and OS4 will drain to proposed inlets at low
points along the north and south sides of Suniga Road. In the interim and
should the City not extend Suniga Road west of the Crowne development, a
riprap diversion channel will be installed at the west end of Suniga Road (at
Crowne’s western boundary) to convey runoff from OS3 and OS4 north and
into a 30” RCP that is stubbed out from the 48” NECCO storm sewer.
14
OS 5 and OS6
Basins OS5 and OS6 represent a portion of the project that drains to the east
along Suniga Road. These basins are part of basin 318 in the Dry Creek EPA
SWMM model. Basin 318 was modified to correctly include the runoff from
these basins. This was done to insure that the impacts to the offsite system
were minimal and met the design intent of the NECCO storm sewer system.
Overflow Conditions
Basins 1-6: Should the inlets at the low spots in these basins clog, the runoff will
flow through the parking lot to the inlets at design points 3, 4, and 6.
Basins 7 and 8: Should the Type R Inlets at design points 7 and 8 clog, storm runoff
will spill east and west down Lupine Drive.
Basin 9: Should the inlet in the LID Basin clog, storm runoff will east and into the
existing inlet near the bottom of the retaining wall along Aspen Heights’ west
boundary.
Basins 10-14: Should the inlets at the low spots in these basins clog, the runoff will
flow through the parking lot to the inlets at design points basins 10, 13 and 14.
Basins 15 and 16: Should the Type R Inlets at design points 15and 16 clog, storm
runoff will spill east down Lupine Drive.
Basin 17: Should the inlet in this basin clog, storm runoff will east onto Jerome
Street.
Basins 18-22: Should the curb cuts or inlets within the LID basins clog, the runoff
will spill south and eventually into the LID basin in basin 23.
Basin 23: Should the inlet in basin 23 clog, the runoff will spill south to Suniga
Road.
Basin 24: Should the existing inlet in basin 24 clog, the runoff will flow to the south
to Suniga Road.
Basin 27: Should the existing inlets in basin 27 clog, the runoff will flow to the
north to the inlet in basin 5.
C. Detention Pond
15
The proposed development does not contain a detention pond. The flow is ultimately
collected in the NECCO storm sewer system. Detention and water quality for the
proposed Crowne development is provided in the NECCO Regional Detention Pond.
D. Street Capacities
Street capacity calculations for public roads have been analyzed and calculated, with
the results provided in Appendix D.
V. STORM WATER QUALITY
A. General Concept & Specific Details
The NECCO regional detention pond provides water quality for the proposed
development.
LID treatment will be provided for the Crowne development through the utilization
of LID basins and porous paver areas. Final sizing and calculations, including the
final LID table will be provided in final design.
VI. EROSION CONTROL
A. General Concept
The subject site lies within the Moderate Rainfall Erodibility Zone and the Moderate
Wind Erodibility Zone per the City of Fort Collins zone maps. The potential exists
for erosion problems during construction, but should be minimal after completion of
proposed development.
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Silt fence has been installed along the north, west, south, and portions of the east side
of the site to prevent sediment from leaving the site, while also providing as a barrier
for adjacent prairie dog mitigation on-site. Vehicle tracking pads will also be placed
at entrances/exits to the site, with the exact location provided during final design.
Straw Wattles and gravel inlet filters will be placed at proposed inlet locations to
mitigate the build-up of sediment in the proposed inlet and manhole structures.
Straw wattle check dams will also be installed at 300' intervals in the proposed
swales throughout the site, as may be applicable.
Erosion Control Calculations and the Erosion Control Escrow Amount will be
provided during final design. Please refer to Appendix G for the Erosion Control
Plan and Erosion Control Notes and Detail Sheets.
VII. CONCLUSIONS
A. Compliance with Standards & Stormwater Operations/Maintenance Procedure
All computations within this report have been completed in compliance with the City
of Fort Collins Storm Drainage Design Criteria.
The City of Fort Collins Storm water Utility will not maintain the on-site storm
drainage facilities within the subject site. The owners of the subject site will
maintain their on-site storm drainage facilities on a regular basis. The following shall
be implemented for the private stormwater improvements’ operations/ maintenance
procedures for the project on an annual or bi-annual basis:
1) Storm Sewer Inlets, pipes and flared-end-sections, curb cuts and concrete
sidewalk culverts/chases, structures, manholes, and the LID outlet control
structures shall be cleaned through the removal of debris and sediment from
the associated items to allow for adequate drainage through the site to the
offsite regional detention facility
2) Re-vegetation through the use of Natural Seeding/ Sod shall be provided for
disturbed areas and other permanent erosion controls shall be provided for
areas where erosion has taken place and requires remediation back to the
proposed condition shown in the plans
The Stormwater Operating/ Maintenance Procedures listed above are guidelines to
the minimum procedures that shall be implemented for the site, with these and
additional measures being utilized on an as-needed basis.
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B. Drainage Concept
The proposed drainage concepts presented in this study and shown on the utility
plans adequately provide for the transmission of developed on-site runoff to the
NECCO regional detention pond. The proposed storm sewer system will provide for
the 100-year developed flows.
If groundwater is encountered at the time of construction, a Colorado Department of
Health Construction Dewatering Permit will be required.
C. Storm Water Quality
Water quality for the site will be provided in the NECCO regional detention pond.
LID measures have also been provided for the project and will be sized accordingly
during final design.
D. Erosion Control Concept
Proposed erosion control concepts will adequately provide for the control of wind
and rainfall erosion from the proposed development. Through the construction of the
proposed erosion control concepts, the City of Fort Collins standards will be met.
The proposed erosion control concepts presented in the preliminary report and shown
on the erosion control plan are in compliance with the City of Fort Collins Erosion
Control Criteria.
E. Erosion Control Escrow Estimate
The Erosion Control Escrow Estimate for the subject property will be provided at
final design.
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REFERENCES
1. Storm Drainage Design Criteria and Construction Standards by the City of Fort Collins,
Colorado, May 1984, Revised January 1997, & Associated UDFCD Updates and New City
of Fort Collins Stormwater Criteria manual, adopted January, 2012.
2. Erosion Control Reference Manual for Construction Sites by the City of Fort Collins,
Colorado, January 1991, Revised January 1997, & Associated UDFCD Updates and New
City of Fort Collins Stormwater Criteria manual, adopted January, 2012.
3. Urban Storm Drainage Criteria Manual Volume 1; Urban Drainage and Flood Control
District, Denver, Colorado, March, 1969.
4. Urban Storm Drainage Criteria Manual Volume 2; Urban Drainage and Flood Control
District, Denver, Colorado, March, 1969.
5. Urban Storm Drainage Criteria Manual Volume 3, Best Management Practices; Urban
Drainage and Flood Control District, Denver, Colorado, September, 1999.
6. Overall Drainage Plans, Aspen Heights, Fort Collins; Owen Consulting Group, Inc.,
October 17, 2013.
7. North East College Corridor Outfall Plans; Ayres Associates, May 2009.
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APPENDIX
18
APPENDIX A
19
VICINITY MAP
VICINITY MAP
20
APPENDIX B
21
RATIONAL METHOD
HYDROLOGY
NECCO Basin Basin(s) Location Drained to Area
(acre)
Composite
I%
Crowne-West 18-23 48-in NECCO Storm Sewer 1.61 68%
Crowne-Main 1-17, OS1 60-in NECCO Storm Sewer 11.10 75%
26 (NECCO Model) 28, OS-2 Add to Conifer (Basin 26; total =1.74ac) 0.60 97%
316 (NECCO Model) OS3
Adjusted NECOO Basin 316
(3.6 + 0.62 ac = 4.2ac )
to include OS3
0.62 76%
318 (NECCO Model) OS4
Adjusted NECOO Basin 318
(0.44 + 0.62ac = 1.11 ac)
to include OS4
0.44 87%
830 (NECCO Model) OS5
Adjusted NECOO Basin 380
(0.50 + 0.96ac = 1.46 ac)
to include OS5
0.96 67%
831 (NECCO Model) OS6
Adjusted NECOO Basin 831
(0.55 + 0.57ac = 1.12 ac)
to include OS6
0.57 89%
Design Points Basin(s) Location Drained to Area
(acre)
Composite
I%
25 25 Aspen Heights 0.02 62%
26 26 Aspen Heights 0.02 70%
27 27 Aspen Heights 0.11 39%
24 24 Existing Inlet 0.03 31%
Flow Summary
Crowne @ Old Town North
501-003
APEX ENGINEERING
6:55 PM
4/18/2017
TIME OF CONCENTRATION
2 year design storm
Crowne @ Old Town North
501-003
t c = t i + t L
C f = 1.00
SUB-BASIN DATA INITIAL/OVERLAND TIME TRAVEL TIME FINAL REMARKS
BASIN AREA C LENGTH SLOPE ti LENGTH CHANNEL SLOPE VELOCITY tL tc
NO. (ac) (ft) (%) (min) (ft) TYPE(a) (%) (ft/s) (min) (min)
1 2 3 4 5 6 7 8 10 12 13
1 0.52 0.70 30 2.0 3.2 120 PA 0.5 1.34 1.5 5.0 Drains to NECCO 66in Storm Sewer (South)
2 0.07 0.58 30 2.0 4.2 70 GW 2.0 2.18 0.5 5.0 Drains to NECCO 66in Storm Sewer (South)
3 0.79 0.88 40 2.0 2.0 200 PA 2.0 2.72 1.2 5.0 Drains to NECCO 66in Storm Sewer (South)
4 0.76 0.94 40 2.0 1.5 195 PA 2.0 2.72 1.2 5.0 Drains to NECCO 66in Storm Sewer (South)
5 0.14 0.39 20 2.0 4.7 60 GW 2.0 2.18 0.5 5.2 Drains to NECCO 66in Storm Sewer (South)
6 0.40 0.93 19 2.0 1.1 127 PA 2.0 2.72 0.8 5.0 Drains to NECCO 66in Storm Sewer (South)
7 0.65 0.64 40 2.0 4.3 220 PA 2.0 2.72 1.3 5.7 Drains to NECCO 66in Storm Sewer (South)
8 0.69 0.68 50 2.0 4.4 220 PA 2.0 2.72 1.3 5.7 Drains to NECCO 66in Storm Sewer (South)
9 0.19 0.54 40 2.0 5.2 60 PA 2.0 2.72 0.4 5.6 Drains to NECCO 66in Storm Sewer (South)
10 1.12 0.94 25 2.0 1.2 115 PA 2.0 2.72 0.7 5.0 Drains to NECCO 66in Storm Sewer (South)
11 0.25 0.92 38 2.0 1.6 125 PA 2.0 2.72 0.8 5.0 Drains to NECCO 66in Storm Sewer (South)
12 0.74 0.74 60 2.0 4.1 150 PA 2.0 2.72 0.9 5.0 Drains to NECCO 66in Storm Sewer (South)
13 0.86 0.77 30 2.0 2.7 210 PA 2.0 2.72 1.3 5.0 Drains to NECCO 66in Storm Sewer (South)
14 0.65 0.91 50 2.0 2.0 135 PA 2.0 2.72 0.8 5.0 Drains to NECCO 66in Storm Sewer (South)
15 1.84 0.66 90 2.0 6.2 370 PA 2.0 2.72 2.3 8.5 Drains to NECCO 48in Storm Sewer (West)
16 1.02 0.78 50 2.0 3.3 415 PA 0.5 1.34 5.2 8.5 Drains to NECCO 48in Storm Sewer (West)
17 0.14 0.50 20 2.0 4.0 120 PA 2.0 2.72 0.7 5.0 Drains to NECCO 48in Storm Sewer (West)
18 0.27 0.90 30 2.0 1.6 140 PA 2.0 2.72 0.9 5.0 Drains to NECCO 48in Storm Sewer (West)
19 0.37 0.68 20 2.0 2.8 125 PA 2.0 2.72 0.8 5.0 Drains to NECCO 48in Storm Sewer (West)
20 0.39 0.81 35 2.0 2.5 150 PA 2.0 2.72 0.9 5.0 Drains to NECCO 48in Storm Sewer (West)
21 0.21 0.62 30 2.0 3.9 75 PA 2.0 2.72 0.5 5.0 Drains to NECCO 48in Storm Sewer (West)
22 0.18 0.82 45 2.0 2.7 90 PA 2.0 2.72 0.6 5.0 Drains to NECCO 48in Storm Sewer (West)
23 0.18 0.32 30 2.0 6.3 115 GW 0.5 1.09 1.8 8.1 Drains to NECCO 48in Storm Sewer (West)
24 0.03 0.43 15 2.0 3.8 15 PA 2.0 2.72 0.1 5.0 Drains to existing inlet SE corner of the site
25 0.02 0.67 25 2.0 3.2 5PA2.02.72 0.0 5.0 Offsite to Aspen Heights
26 0.02 0.72 25 2.0 2.8 5PA2.02.72 0.0 5.0 Offsite to Aspen Heights
27 0.11 0.51 30 2.0 4.8 5PA2.02.72 0.0 5.0 Drains to NECCO 66in Storm Sewer (South)
28 0.48 0.61 30 2.0 4.0 100 PA 2.0 2.72 0.6 5.0 Drains to Conifer
t
CC D
i S
f
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0333
.( . )
.
ASPEN ENGINEERING
9:43 PM
2/13/2017
SUB-BASIN DATA INITIAL/OVERLAND TIME TRAVEL TIME FINAL REMARKS
BASIN AREA C LENGTH SLOPE ti LENGTH CHANNEL SLOPE VELOCITY tL tc
NO. (ac) (ft) (%) (min) (ft) TYPE(a) (%) (ft/s) (min) (min)
1 2 3 4 5 6 7 8 10 12 13
OS1 0.26 0.78 53 2.0 3.5 230 PA 0.5 1.34 2.9 6.4 Drains to NECCO 48in Storm Sewer (West)
OS2 0.12 0.83 11.0 0.5 1PA1.01.91 0.0 5.0 Drains to Conifer
OS3 0.62 0.77 60 2.0 3.8 245 PA 1.0 1.91 2.1 6.0 Drains to Suniga
OS4 0.44 0.84 60 2.0 2.9 245 PA 1.0 1.91 2.1 5.1 Drains to Suniga
OS5 0.96 0.70 60 2.0 4.5 350 PA 1.0 1.91 3.1 7.6 Drains to Suniga
OS6 0.57 0.86 60 2.0 2.8 350 PA 1.0 1.91 3.1 5.9 Drains to Suniga
Note:
a) Codes the channel type for velocity calculations.
PA = Paved, PL = Pasture & Lawns, GW = Grassed Waterway
ASPEN ENGINEERING
9:43 PM
2/13/2017
Basin Roof Area (sqft) Asphalt Area (sqft) Concrete Area (sqft) Gravel Area (sqft) Lawn Area (sqft) Total Area Total Area Composite
No. "C=0.90" "C=0.95" "C=0.90" "C=0.41" "C=0.25" (sqft) (acre) "C"
1 2,450 10,840 1,500 0 7,715 22,505 0.52 0.70
2 1,400 0 50 0 1,395 2,845 0.07 0.58
3 7,905 22,750 1,200 0 2,637 34,492 0.79 0.88
4 4,230 28,500 250 0 282 33,262 0.76 0.94
5 1,095 0 250 0 4,936 6,281 0.14 0.39
6 2,900 13,100 1,200 0 250 17,450 0.40 0.93
7 8,400 5,180 3,130 0 11,753 28,463 0.65 0.64
8 5,255 10,453 3,680 0 10,792 30,180 0.69 0.68
9 2,280 0 1,360 0 4,445 8,085 0.19 0.54
10 5,065 41,809 1,500 0 250 48,624 1.12 0.94
11 1,500 8,369 750 0 250 10,869 0.25 0.92
12 10,880 8,400 4,400 0 8,465 32,145 0.74 0.74
13 5,310 19,528 3,990 0 8,847 37,675 0.86 0.77
14 4,465 20,348 2,500 0 1,200 28,513 0.65 0.91
15 16,470 23,500 8,550 0 31,709 80,229 1.84 0.66
16 6,970 21,530 6,300 0 9,817 44,617 1.02 0.78
17 2,260 0 75 0 3,714 6,049 0.14 0.50
18 3,711 7,300 44 0 505 11,560 0.27 0.90
19 550 9,340 0 0 6,174 16,064 0.37 0.68
20 1,800 9,790 2,500 0 3,051 17,141 0.39 0.81
21 1,370 3,220 450 0 4,226 9,266 0.21 0.62
22 1,950 3,950 765 0 1,218 7,883 0.18 0.82
23 825 0 90 0 7,125 8,040 0.18 0.32
24 100 0 250 0 905 1,255 0.03 0.43
25 0 575 0 0 376 951 0.02 0.67
26 0 580 120 0 323 1,023 0.02 0.72
Developed Weighted Runoff Coefficients
Crowne @ Old Town North
501-003
aspen engineering
9:46 PM
2/13/2017
27 1,600 50 270 0 2,961 4,881 0.11 0.51
28 3,140 4,830 3,150 0 9,911 21,031 0.48 0.61
OS1 0 6,600 1,900 0 2,609 11,109 0.26 0.78
OS2 0 3,110 1,250 0 805 5,165 0.12 0.83
OS3 880 16,073 3,500 0 6,740 27,193 0.62 0.77
OS4 0 13,200 3,200 0 2,668 19,068 0.44 0.84
OS5 8,450 15,200 4,500 0 13,763 41,913 0.96 0.70
OS6 0 17,500 4,500 0 3,028 25,028 0.57 0.86
Total SITE 113,211 345,624 67,174 0 174,844 700,853 0.76
Total Acreage 2.60 7.93 1.54 0.00 4.01 16.09
Impervious Ratio
Basin Roof Area (sqft) Asphalt Area (sqft) Concrete Area (sqft) Gravel Area (sqft) Lawn Area (sqft) Total Area Imperviousness
No. (sqft) Ratio
1 2,450 10,840 1,500 0 7,715 22,505 66%
2 1,400 0 50 0 1,395 2,845 48%
3 7,905 22,750 1,200 0 2,637 34,492 90%
4 4,230 28,500 250 0 282 33,262 98%
5 1,095 0 250 0 4,936 6,281 24%
6 2,900 13,100 1,200 0 250 17,450 97%
7 8,400 5,180 3,130 0 11,753 28,463 58%
8 5,255 10,453 3,680 0 10,792 30,180 64%
9 2,280 0 1,360 0 4,445 8,085 45%
10 5,065 41,809 1,500 0 250 48,624 98%
11 1,500 8,369 750 0 250 10,869 96%
12 10,880 8,400 4,400 0 8,465 32,145 72%
13 5,310 19,528 3,990 0 8,847 37,675 76%
14 4,465 20,348 2,500 0 1,200 28,513 94%
15 16,470 23,500 8,550 0 31,709 80,229 60%
16 6,970 21,530 6,300 0 9,817 44,617 78%
17 2,260 0 75 0 3,714 6,049 38%
18 3,711 7,300 44 0 505 11,560 93%
19 550 9,340 0 0 6,174 16,064 63%
20 1,800 9,790 2,500 0 3,051 17,141 82%
21 1,370 3,220 450 0 4,226 9,266 55%
22 1,950 3,950 765 0 1,218 7,883 83%
23 825 0 90 0 7,125 8,040 15%
aspen engineering
9:46 PM
2/13/2017
24 100 0 250 0 905 1,255 31%
25 0 575 0 0 376 951 62%
26 0 580 120 0 323 1,023 70%
27 1,600 50 270 0 2,961 4,881 39%
28 3,140 4,830 3,150 0 9,911 21,031 54%
OS1 0 6,600 1,900 0 2,609 11,109 78%
OS2 0 3,110 1,250 0 805 5,165 85%
OS3 880 16,073 3,500 0 6,740 27,193 76%
OS4 0 13,200 3,200 0 2,668 19,068 87%
OS5 8,450 15,200 4,500 0 13,763 41,913 67%
OS6 0 17,500 4,500 0 3,028 25,028 89%
Total SITE 113,211 345,624 67,174 0 174,844 700,853 76%
Total Acreage 2.60 7.93 1.54 0.00 4.01 16.09 75%
aspen engineering
9:46 PM
2/13/2017
TIME OF CONCENTRATION
100 year design storm
Crowne @ Old Town North
501-003
t c = t i + t L
C f = 1.25
SUB-BASIN DATA INITIAL/OVERLAND TIME TRAVEL TIME FINAL REMARKS
BASIN AREA C LENGTH SLOPE ti LENGTH CHANNEL SLOPE VELOCITY tL tc
NO. (ac) (ft) (%) (min) (ft) TYPE(a) (%) (ft/s) (min) (min)
1 2 3 4 5 6 7 8 10 12 13
1 0.52 0.70 30 2.00 1.8 120 PA 0.50 1.34 1.5 5.0
2 0.07 0.58 30 2.00 3.0 70 GW 2.00 2.18 0.5 5.0
3 0.79 0.88 40 2.00 0.9 200 PA 2.00 2.72 1.2 5.0
4 0.76 0.94 40 2.00 0.9 195 PA 2.00 2.72 1.2 5.0
5 0.14 0.39 20 2.00 4.1 60 GW 2.00 2.18 0.5 5.0
6 0.40 0.93 19 2.00 0.6 127 PA 2.00 2.72 0.8 5.0
7 0.65 0.64 40 2.00 2.8 220 PA 2.00 2.72 1.3 5.0
8 0.69 0.68 50 2.00 2.6 220 PA 2.00 2.72 1.3 5.0
9 0.19 0.54 40 2.00 4.0 60 PA 2.00 2.72 0.4 5.0
10 1.12 0.94 25 2.00 0.7 115 PA 2.00 2.72 0.7 5.0
11 0.25 0.92 38 2.00 0.9 125 PA 2.00 2.72 0.8 5.0
12 0.74 0.74 60 2.00 2.0 150 PA 2.00 2.72 0.9 5.0
13 0.86 0.77 30 2.00 1.1 210 PA 2.00 2.72 1.3 5.0
14 0.65 0.91 50 2.00 1.0 135 PA 2.00 2.72 0.8 5.0
15 1.84 0.66 90 2.00 3.9 370 PA 2.00 2.72 2.3 6.2
16 1.02 0.78 50 2.00 1.3 415 PA 0.50 1.34 5.2 6.5
17 0.14 0.50 20 2.00 3.1 120 PA 2.00 2.72 0.7 5.0
18 0.27 0.90 30 2.00 0.8 140 PA 2.00 2.72 0.9 5.0
19 0.37 0.68 20 2.00 1.7 125 PA 2.00 2.72 0.8 5.0
20 0.39 0.81 35 2.00 0.9 150 PA 2.00 2.72 0.9 5.0
21 0.21 0.62 30 2.00 2.6 75 PA 2.00 2.72 0.5 5.0
22 0.18 0.82 45 2.00 1.0 90 PA 2.00 2.72 0.6 5.0
23 0.18 0.32 30 2.00 5.7 115 GW 0.50 1.09 1.8 7.4
24 0.03 0.43 15 2.00 3.2 15 PA 2.00 2.72 0.1 5.0
25 0.02 0.67 25 2.00 1.9 5 PA 2.00 2.72 0.0 5.0
26 0.02 0.72 25 2.00 1.5 5 PA 2.00 2.72 0.0 5.0
27 0.11 0.51 30 2.00 3.8 5 PA 2.00 2.72 0.0 5.0
28 0.48 0.61 30 2.00 2.8 100 PA 2.00 2.72 0.6 5.0
t
CC D
i S
f
187 11
0333
.( . )
.
ASPEN ENGINEERING
9:48 PM
2/13/2017
SUB-BASIN DATA INITIAL/OVERLAND TIME TRAVEL TIME FINAL REMARKS
BASIN AREA C LENGTH SLOPE ti LENGTH CHANNEL SLOPE VELOCITY tL tc
NO. (ac) (ft) (%) (min) (ft) TYPE(a) (%) (ft/s) (min) (min)
1 2 3 4 5 6 7 8 10 12 13
OS1 0.26 0.78 53 2.00 1.4 230 PA 0.50 1.34 2.9 5.0
OS2 0.12 0.83 1 1.00 0.2 1 PA 1.00 1.91 0.0 5.0
OS3 0.62 0.77 60 2.00 1.6 245 PA 1.00 1.91 2.1 5.0
OS4 0.44 0.84 60 2.00 1.1 245 PA 1.00 1.91 2.1 5.0
OS5 0.96 0.70 60 2.00 2.5 350 PA 1.00 1.91 3.1 5.6
OS6 0.57 0.86 60 2.00 1.1 350 PA 1.00 1.91 3.1 5.0
Note:
a) Codes the channel type for velocity calculations.
PA = Paved, PL = Pasture & Lawns, GW = Grassed Waterway
ASPEN ENGINEERING
9:48 PM
2/13/2017
Business:
Commercial areas
Neighborhood areas
Residential:
Single-family
Multiunit (detached)
Multiunit (attached)
Half-acre lot or larger
Apartments
Industrial:
Light areas
Heavy areas
Parks, cemeteries:
Playgrounds:
Schools:
Railroad yard areas:
Undeveloped areas:
Historical Flow Analysis
Greenbelts, agricultural
Off-site flow analysis
(when land use not defined)
Streets:
Paved
Gravel (packed)
Driveways and sidewalks:
Roofs:
Lawns, sandy soil
Lawns, clayey soil
*Refer to Figures RO-3 through RO-5 in Runoff Chapter
Land Use or Surface Characteristics Percent Imper-viousness
95
85
*
60
75
*
80
80
90
5
10
50
15
2
45
0
0
100
40
90
90
aspen engineering
9:46 PM
2/13/2017
31
LID Summary
New Impervious Area 328,794 sf
Required Minimum Impervious Area to be Treated (50% of Imp. Area) 164,397 sf
Impervious Area Treated by LID Treatment Method #1 (LID Basin DP 23) 64,806 sf
Impervious Area Treated by LID Treatment Method #2 (L0D DP 27) 6,531 sf
Impervious Area Treated by LID Treatment Method #3 (LID Basin DP 3) 31,196 sf
Impervious Area Treated by LID Treatment Method #4 (LID Basin DP 4) 32,571 sf
Impervious Area Treated by LID Treatment Method #5 (LID Basin DP 9) 3,634 sf
Impervious Area Treated by LID Treatment Method #6 (LOD DP 11) 10,482 sf
Impervious Area Treated by LID Treatment Method #7 (LID Basin DP 1) 14,931 sf
Impervious Area Treated by LID Treatment Method #8 (Porous Pavement) 20,074
Total Impervious Area Treated 184,224 sf
Percent LID Treatment Provided for Entire Site Area 56%
New Pavement Area 345,624 sf
Required Minimum Area of Porous Pavement (25% of New Pvmt. Area) 86,406 sf
Area of Paver Section #1 4,684 sf
Run‐on area for Paver Section #1 (up to 3:1 is permitted) 4,684 sf
Area of Paver Section #2 3,667 sf
Run‐on area for Paver Section #2 (up to 3:1 is permitted) 7,334 sf
Area of Paver Section #3 4,028 sf
Run‐on area for Paver Section #3 (up to 3:1 is permitted) 8,056 sf
Area of Paver Section #4 4,028 sf
Run‐on area for Paver Section #4 (up to 3:1 is permitted) 8,056 sf
Area of Paver Section #4 3,667 sf
Run‐on area for Paver Section #4 (up to 3:1 is permitted) 7,334 sf
Total Porous Pavement Area for Site 20,074 sf
Allowable Run‐on Area for Site 60,221 sf
Total Run‐on Area Utilized for Site 35,464 sf
LID TABLE
31
NECCO Summary
WSEL (ft) Flow (cfs) WSEL (ft) Flow (cfs)
Inlet_C3A 4971.23 72.64 4969.27 72.64
Inlet_C4B 4970.66 27.48 4969 28.71
In_803 4970.15 81.77 4968.44 130.32
In_804 4967.79 232.83 4964.16 168.96
In_805 4965.76 281.38 4963.04 225.22
Regional_Pond 4961.17 873.67 4961.07 873.67
Inlet_C6A 4962.97 10.75 4962.99 11.03
Area (ac) Q100 (cfs) Area (ac) Q100 (cfs)
404 19.2 191.46 ‐‐‐ ‐‐‐
316 4.2 27.48 4.2 28.7
318 1 9.83 1.11 10.87
830 1.1 10.75 1.46 14.04
831 1.1 10.84 1.12 11.03
26 1.2 11.69 1.74 16.73
Crowe‐Main ‐‐‐ ‐‐‐ 7.84 74.37
Crowe‐West ‐‐‐ ‐‐‐ 4.87 45.15
404a ‐‐‐ ‐‐‐ 2.35 22.24
NECCO EPA SWMM Impact Summary
Basin
Basin Summary Impacted by Project
Master Plan Proposed
Master Plan Proposed
Node Name
Node Summary Downstream of Project
EPA SWMM
EPASWMM Basins ‐ Master Plan
404
26
830
831
318
316
EPA SWMM
ne2
EPASWMM Basins – Proposed Project Adjustments
404a
26
830
831
318
316
Crowe‐Main
Crowe‐West
EPA SWMM
EPASWMM Basins – Master Plan Nodes
Inlet_C3A
Inlet_C6B
IN_803
Inlet_C6A
IN_804
IN_805 Regional Pond
22
APPENDIX C
23
STORM SEWER PIPE SIZING
(TO BE PROVIDED AT FINAL DESIGN)
Project Description
Friction Method Manning Formula
Solve For Full Flow Capacity
Input Data
Roughness Coefficient 0.013
Channel Slope 0.00400 ft/ft
Normal Depth 1.00 ft
Diameter 1.00 ft
Discharge 2.25 ft³/s
Results
Discharge 2.25 ft³/s
Normal Depth 1.00 ft
Flow Area 0.79 ft²
Wetted Perimeter 3.14 ft
Hydraulic Radius 0.25 ft
Top Width 0.00 ft
Critical Depth 0.64 ft
Percent Full 100.0 %
Critical Slope 0.00724 ft/ft
Velocity 2.87 ft/s
Velocity Head 0.13 ft
Specific Energy 1.13 ft
Froude Number 0.00
Maximum Discharge 2.42 ft³/s
Discharge Full 2.25 ft³/s
Slope Full 0.00400 ft/ft
Flow Type SubCritical
GVF Input Data
Downstream Depth 0.00 ft
Length 0.00 ft
Number Of Steps 0
GVF Output Data
Upstream Depth 0.00 ft
Profile Description
Profile Headloss 0.00 ft
Average End Depth Over Rise 0.00 %
12-in Pipe
2/13/2017 9:53:32 PM
Bentley Systems, Inc. Haestad Methods Solution Bentley Center FlowMaster V8i (SELECTseries 1) [08.11.01.03]
27 Siemons Company Drive Suite 200 W Watertown, CT 06795 USA +1-203-755-1666 Page 1 of 2
GVF Output Data
Normal Depth Over Rise 100.00 %
Downstream Velocity Infinity ft/s
Upstream Velocity Infinity ft/s
Normal Depth 1.00 ft
Critical Depth 0.64 ft
Channel Slope 0.00400 ft/ft
Critical Slope 0.00724 ft/ft
12-in Pipe
2/13/2017 9:53:32 PM
Bentley Systems, Inc. Haestad Methods Solution Bentley Center FlowMaster V8i (SELECTseries 1) [08.11.01.03]
27 Siemons Company Drive Suite 200 W Watertown, CT 06795 USA +1-203-755-1666 Page 2 of 2
Project Description
Friction Method Manning Formula
Solve For Full Flow Capacity
Input Data
Roughness Coefficient 0.013
Channel Slope 0.00400 ft/ft
Normal Depth 1.50 ft
Diameter 1.50 ft
Discharge 6.64 ft³/s
Results
Discharge 6.64 ft³/s
Normal Depth 1.50 ft
Flow Area 1.77 ft²
Wetted Perimeter 4.71 ft
Hydraulic Radius 0.38 ft
Top Width 0.00 ft
Critical Depth 1.00 ft
Percent Full 100.0 %
Critical Slope 0.00656 ft/ft
Velocity 3.76 ft/s
Velocity Head 0.22 ft
Specific Energy 1.72 ft
Froude Number 0.00
Maximum Discharge 7.15 ft³/s
Discharge Full 6.64 ft³/s
Slope Full 0.00400 ft/ft
Flow Type SubCritical
GVF Input Data
Downstream Depth 0.00 ft
Length 0.00 ft
Number Of Steps 0
GVF Output Data
Upstream Depth 0.00 ft
Profile Description
Profile Headloss 0.00 ft
Average End Depth Over Rise 0.00 %
18-in Pipe
2/13/2017 9:53:56 PM
Bentley Systems, Inc. Haestad Methods Solution Bentley Center FlowMaster V8i (SELECTseries 1) [08.11.01.03]
27 Siemons Company Drive Suite 200 W Watertown, CT 06795 USA +1-203-755-1666 Page 1 of 2
GVF Output Data
Normal Depth Over Rise 100.00 %
Downstream Velocity Infinity ft/s
Upstream Velocity Infinity ft/s
Normal Depth 1.50 ft
Critical Depth 1.00 ft
Channel Slope 0.00400 ft/ft
Critical Slope 0.00656 ft/ft
18-in Pipe
2/13/2017 9:53:56 PM
Bentley Systems, Inc. Haestad Methods Solution Bentley Center FlowMaster V8i (SELECTseries 1) [08.11.01.03]
27 Siemons Company Drive Suite 200 W Watertown, CT 06795 USA +1-203-755-1666 Page 2 of 2
Project Description
Friction Method Manning Formula
Solve For Full Flow Capacity
Input Data
Roughness Coefficient 0.013
Channel Slope 0.00400 ft/ft
Normal Depth 2.00 ft
Diameter 2.00 ft
Discharge 14.31 ft³/s
Results
Discharge 14.31 ft³/s
Normal Depth 2.00 ft
Flow Area 3.14 ft²
Wetted Perimeter 6.28 ft
Hydraulic Radius 0.50 ft
Top Width 0.00 ft
Critical Depth 1.36 ft
Percent Full 100.0 %
Critical Slope 0.00613 ft/ft
Velocity 4.55 ft/s
Velocity Head 0.32 ft
Specific Energy 2.32 ft
Froude Number 0.00
Maximum Discharge 15.39 ft³/s
Discharge Full 14.31 ft³/s
Slope Full 0.00400 ft/ft
Flow Type SubCritical
GVF Input Data
Downstream Depth 0.00 ft
Length 0.00 ft
Number Of Steps 0
GVF Output Data
Upstream Depth 0.00 ft
Profile Description
Profile Headloss 0.00 ft
Average End Depth Over Rise 0.00 %
24-in Pipe
2/13/2017 9:54:18 PM
Bentley Systems, Inc. Haestad Methods Solution Bentley Center FlowMaster V8i (SELECTseries 1) [08.11.01.03]
27 Siemons Company Drive Suite 200 W Watertown, CT 06795 USA +1-203-755-1666 Page 1 of 2
GVF Output Data
Normal Depth Over Rise 100.00 %
Downstream Velocity Infinity ft/s
Upstream Velocity Infinity ft/s
Normal Depth 2.00 ft
Critical Depth 1.36 ft
Channel Slope 0.00400 ft/ft
Critical Slope 0.00613 ft/ft
24-in Pipe
2/13/2017 9:54:18 PM
Bentley Systems, Inc. Haestad Methods Solution Bentley Center FlowMaster V8i (SELECTseries 1) [08.11.01.03]
27 Siemons Company Drive Suite 200 W Watertown, CT 06795 USA +1-203-755-1666 Page 2 of 2
Project Description
Friction Method Manning Formula
Solve For Full Flow Capacity
Input Data
Roughness Coefficient 0.013
Channel Slope 0.00400 ft/ft
Normal Depth 2.50 ft
Diameter 2.50 ft
Discharge 25.94 ft³/s
Results
Discharge 25.94 ft³/s
Normal Depth 2.50 ft
Flow Area 4.91 ft²
Wetted Perimeter 7.85 ft
Hydraulic Radius 0.63 ft
Top Width 0.00 ft
Critical Depth 1.74 ft
Percent Full 100.0 %
Critical Slope 0.00583 ft/ft
Velocity 5.28 ft/s
Velocity Head 0.43 ft
Specific Energy 2.93 ft
Froude Number 0.00
Maximum Discharge 27.90 ft³/s
Discharge Full 25.94 ft³/s
Slope Full 0.00400 ft/ft
Flow Type SubCritical
GVF Input Data
Downstream Depth 0.00 ft
Length 0.00 ft
Number Of Steps 0
GVF Output Data
Upstream Depth 0.00 ft
Profile Description
Profile Headloss 0.00 ft
Average End Depth Over Rise 0.00 %
30-in Pipe
2/13/2017 9:54:34 PM
Bentley Systems, Inc. Haestad Methods Solution Bentley Center FlowMaster V8i (SELECTseries 1) [08.11.01.03]
27 Siemons Company Drive Suite 200 W Watertown, CT 06795 USA +1-203-755-1666 Page 1 of 2
GVF Output Data
Normal Depth Over Rise 100.00 %
Downstream Velocity Infinity ft/s
Upstream Velocity Infinity ft/s
Normal Depth 2.50 ft
Critical Depth 1.74 ft
Channel Slope 0.00400 ft/ft
Critical Slope 0.00583 ft/ft
30-in Pipe
2/13/2017 9:54:34 PM
Bentley Systems, Inc. Haestad Methods Solution Bentley Center FlowMaster V8i (SELECTseries 1) [08.11.01.03]
27 Siemons Company Drive Suite 200 W Watertown, CT 06795 USA +1-203-755-1666 Page 2 of 2
Project Description
Friction Method Manning Formula
Solve For Full Flow Capacity
Input Data
Roughness Coefficient 0.013
Channel Slope 0.00400 ft/ft
Normal Depth 3.00 ft
Diameter 3.00 ft
Discharge 42.18 ft³/s
Results
Discharge 42.18 ft³/s
Normal Depth 3.00 ft
Flow Area 7.07 ft²
Wetted Perimeter 9.42 ft
Hydraulic Radius 0.75 ft
Top Width 0.00 ft
Critical Depth 2.12 ft
Percent Full 100.0 %
Critical Slope 0.00560 ft/ft
Velocity 5.97 ft/s
Velocity Head 0.55 ft
Specific Energy 3.55 ft
Froude Number 0.00
Maximum Discharge 45.37 ft³/s
Discharge Full 42.18 ft³/s
Slope Full 0.00400 ft/ft
Flow Type SubCritical
GVF Input Data
Downstream Depth 0.00 ft
Length 0.00 ft
Number Of Steps 0
GVF Output Data
Upstream Depth 0.00 ft
Profile Description
Profile Headloss 0.00 ft
Average End Depth Over Rise 0.00 %
36-in Pipe
2/13/2017 9:54:51 PM
Bentley Systems, Inc. Haestad Methods Solution Bentley Center FlowMaster V8i (SELECTseries 1) [08.11.01.03]
27 Siemons Company Drive Suite 200 W Watertown, CT 06795 USA +1-203-755-1666 Page 1 of 2
GVF Output Data
Normal Depth Over Rise 100.00 %
Downstream Velocity Infinity ft/s
Upstream Velocity Infinity ft/s
Normal Depth 3.00 ft
Critical Depth 2.12 ft
Channel Slope 0.00400 ft/ft
Critical Slope 0.00560 ft/ft
36-in Pipe
2/13/2017 9:54:51 PM
Bentley Systems, Inc. Haestad Methods Solution Bentley Center FlowMaster V8i (SELECTseries 1) [08.11.01.03]
27 Siemons Company Drive Suite 200 W Watertown, CT 06795 USA +1-203-755-1666 Page 2 of 2
Project Description
Friction Method Manning Formula
Solve For Full Flow Capacity
Input Data
Roughness Coefficient 0.013
Channel Slope 0.00400 ft/ft
Normal Depth 3.00 ft
Diameter 3.00 ft
Discharge 42.18 ft³/s
Results
Discharge 42.18 ft³/s
Normal Depth 3.00 ft
Flow Area 7.07 ft²
Wetted Perimeter 9.42 ft
Hydraulic Radius 0.75 ft
Top Width 0.00 ft
Critical Depth 2.12 ft
Percent Full 100.0 %
Critical Slope 0.00560 ft/ft
Velocity 5.97 ft/s
Velocity Head 0.55 ft
Specific Energy 3.55 ft
Froude Number 0.00
Maximum Discharge 45.37 ft³/s
Discharge Full 42.18 ft³/s
Slope Full 0.00400 ft/ft
Flow Type SubCritical
GVF Input Data
Downstream Depth 0.00 ft
Length 0.00 ft
Number Of Steps 0
GVF Output Data
Upstream Depth 0.00 ft
Profile Description
Profile Headloss 0.00 ft
Average End Depth Over Rise 0.00 %
42-in Pipe
2/13/2017 9:55:09 PM
Bentley Systems, Inc. Haestad Methods Solution Bentley Center FlowMaster V8i (SELECTseries 1) [08.11.01.03]
27 Siemons Company Drive Suite 200 W Watertown, CT 06795 USA +1-203-755-1666 Page 1 of 2
GVF Output Data
Normal Depth Over Rise 100.00 %
Downstream Velocity Infinity ft/s
Upstream Velocity Infinity ft/s
Normal Depth 3.00 ft
Critical Depth 2.12 ft
Channel Slope 0.00400 ft/ft
Critical Slope 0.00560 ft/ft
42-in Pipe
2/13/2017 9:55:09 PM
Bentley Systems, Inc. Haestad Methods Solution Bentley Center FlowMaster V8i (SELECTseries 1) [08.11.01.03]
27 Siemons Company Drive Suite 200 W Watertown, CT 06795 USA +1-203-755-1666 Page 2 of 2
Project Description
Friction Method Manning Formula
Solve For Full Flow Capacity
Input Data
Roughness Coefficient 0.013
Channel Slope 0.00400 ft/ft
Normal Depth 4.00 ft
Diameter 4.00 ft
Discharge 90.84 ft³/s
Results
Discharge 90.84 ft³/s
Normal Depth 4.00 ft
Flow Area 12.57 ft²
Wetted Perimeter 12.57 ft
Hydraulic Radius 1.00 ft
Top Width 0.00 ft
Critical Depth 2.89 ft
Percent Full 100.0 %
Critical Slope 0.00526 ft/ft
Velocity 7.23 ft/s
Velocity Head 0.81 ft
Specific Energy 4.81 ft
Froude Number 0.00
Maximum Discharge 97.72 ft³/s
Discharge Full 90.84 ft³/s
Slope Full 0.00400 ft/ft
Flow Type SubCritical
GVF Input Data
Downstream Depth 0.00 ft
Length 0.00 ft
Number Of Steps 0
GVF Output Data
Upstream Depth 0.00 ft
Profile Description
Profile Headloss 0.00 ft
Average End Depth Over Rise 0.00 %
48-in Pipe
2/13/2017 9:55:31 PM
Bentley Systems, Inc. Haestad Methods Solution Bentley Center FlowMaster V8i (SELECTseries 1) [08.11.01.03]
27 Siemons Company Drive Suite 200 W Watertown, CT 06795 USA +1-203-755-1666 Page 1 of 2
GVF Output Data
Normal Depth Over Rise 100.00 %
Downstream Velocity Infinity ft/s
Upstream Velocity Infinity ft/s
Normal Depth 4.00 ft
Critical Depth 2.89 ft
Channel Slope 0.00400 ft/ft
Critical Slope 0.00526 ft/ft
48-in Pipe
2/13/2017 9:55:31 PM
Bentley Systems, Inc. Haestad Methods Solution Bentley Center FlowMaster V8i (SELECTseries 1) [08.11.01.03]
27 Siemons Company Drive Suite 200 W Watertown, CT 06795 USA +1-203-755-1666 Page 2 of 2
24
APPENDIX D
25
*INLET, *CONCRETE SIDEWALK
CULVERT SIZING, PUBLIC
STREET CAPACITIES
(*TO BE PROVIDED AT FINAL DESIGN)
Street Capacity
Computes flow capacities for a given section of Road
Major Storm
Design contraints:
Local: The depth of water over the crown shall not exceed 6 inches.
Arterial and Major Arterial: Depth of water not to exceed 6 inches above the crown or 18 inches above gutter flowline.
* Road width equals the width of pavement covered by water for one side of the road out from the edge of gutter pan.
Driveover Curb & Gutter
Design Point 7 8 15 16 19 OS3 OS4 OS5 OS6
Input
*Width of road section from edge of gutter pan (ft.): 20.00 20.00 20.00 20.00 20.00 20.00 20.00 20.00 20.00
Road elevation at end of road width (ft.): 2.00 2.00 2.00 2.00 2.00 2.00 2.00 2.00 2.00
Flood water elevation (ft.): 2.50 2.50 2.50 2.50 2.50 2.50 2.50 2.50 2.50
Gutter slope (ft/ft): 0.01 0.01 0.01 0.01 0.01 0.01 0.01 0.01 0.01
Cross slope of road (ft/ft): 0.02 0.02 0.02 0.02 0.02 0.02 0.02 0.02 0.02
Cross slope behind back of walk (decimal): 0.02 0.02 0.02 0.02 0.02 0.02 0.02 0.02 0.02
Output
Theoretical Capacity (cfs): 74.29 74.29 74.29 74.29 74.29 74.29 74.29 74.29 74.29
Theoretical Velocity (ft/s): 3.02 3.02 3.02 3.02 3.02 3.02 3.02 3.02 3.02
Reduction Factor: 0.80 0.80 0.80 0.80 0.80 0.80 0.80 0.80 0.80
Allowable Capacity (cfs): 59.43 59.43 59.43 59.43 59.43 59.43 59.43 59.43 59.43
Q100 5.21 5.90 14.07 9.14 3.12 5.97 4.36 8.15 5.72
Vertical Curb & Gutter
Design Point 7 8 15 16 19 OS3 OS4 OS5 OS6
Input
*Width of road section from edge of gutter pan (ft.): 15.00 15.00 15.00 15.00 15.00 15.00 15.00 15.00 15.00
Road elevation at end of road width (ft.): 0.41 0.41 0.41 0.41 0.41 0.41 0.41 0.41 0.41
Flood water elevation (ft.): 0.91 0.91 0.91 0.91 0.91 0.91 0.91 0.91 0.91
Gutter slope (ft/ft): 0.005 0.005 0.005 0.005 0.005 0.005 0.005 0.005 0.005
Cross slope of road (ft/ft): 0.02 0.02 0.02 0.02 0.02 0.02 0.02 0.02 0.02
Cross slope of sidewalk (ft/ft): 0.02 0.02 0.02 0.02 0.02 0.02 0.02 0.02 0.02
Sidewalk width (ft.): 4.50 4.50 4.50 4.50 4.50 4.50 4.50 4.50 4.50
Detachment width (ft.): 5.50 5.50 5.50 5.50 5.50 5.50 5.50 5.50 5.50
Cross slope of detachment (ft/ft): 0.02 0.02 0.02 0.02 0.02 0.02 0.02 0.02 0.02
Cross slope behind back of walk (ft/ft): 0.02 0.02 0.02 0.02 0.02 0.02 0.02 0.02 0.02
Output
Check flood depth over gutter flowline (< 1.5 ft.) OK OK OK OK OK OK OK OK OK
Theoretical Capacity (cfs): 40.08 40.08 40.08 40.08 40.08 40.08 40.08 40.08 40.08
Theoretical Velocity (ft/s): 2.11 2.11 2.11 2.11 2.11 2.11 2.11 2.11 2.11
Reduction Factor: 0.65 0.65 0.65 0.65 0.65 0.65 0.65 0.65 0.65
Allowable Capacity (cfs): 26.05 26.05 26.05 26.05 26.05 26.05 26.05 26.05 26.05
Q100 5.21 5.90 14.07 9.14 3.12 5.97 4.36 8.15 5.72
Crowne @ Old Town North
501-003
The Sear-Brown Group
10:10 PM
2/13/2017
Street Capacity
Computes flow capacities for a given section of Road
Minor Storm
Design constraints:
Local: No curb-topping. Flow may spread to crown of streeet.
Collector: No curb-topping. Flow spread must leave at least one lane width free of water.
Major Arteial: No curb-topping. Flow must leave at least 1/2 of roadway width free of water in each direction.
Vertical Curb & Gutter
Design Point 7 8 15 16 19 OS3 OS4 OS5 OS6
Input
Flood water elevation (ft.): 0.50 0.50 0.50 0.50 0.50 0.50 0.50 0.50 0.50
Gutter flowline elevation (ft.): 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00
Cross slope of road (ft/ft): 0.02 0.02 0.02 0.02 0.02 0.02 0.02 0.02 0.02
Gutter slope (ft/ft): 0.005 0.005 0.005 0.005 0.005 0.005 0.005 0.005 0.005
Output
Lateral spread of water from edge of gutter pan: 16.50 16.50 16.50 16.50 16.50 16.50 16.50 16.50 16.50
Theoretical Capacity (cfs): 9.57 9.57 9.57 9.57 9.57 9.57 9.57 9.57 9.57
Theoretical Velocity (ft/s): 2.69 2.69 2.69 2.69 2.69 2.69 2.69 2.69 2.69
Reduction Factor: 0.65 0.65 0.65 0.65 0.65 0.65 0.65 0.65 0.65
Allowable Capacity (cfs): 6.22 6.22 6.22 6.22 6.22 6.22 6.22 6.22 6.22
Q2 1.15 1.30 2.86 1.89 0.71 1.29 1.05 1.67 1.32
Driveover Curb & Gutter
Design Point 7 8 15 16 19 OS3 OS4 OS5 OS6
Input
Flood water elevation (ft.): 0.39 0.39 0.39 0.39 0.39 0.39 0.39 0.39 0.39
Gutter flowline elevation (ft.): 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00
Cross slope of road (ft/ft): 0.02 0.02 0.02 0.02 0.02 0.02 0.02 0.02 0.02
Gutter slope (ft/ft): 0.01 0.01 0.00 0.00 0.00 0.00 0.00 0.00 0.00
Output
Lateral spread of water from edge of gutter pan: 13.80 13.80 13.80 13.80 13.80 13.80 13.80 13.80 13.80
Theoretical Capacity (cfs): 7.11 10.05 0.00 0.00 0.00 0.00 0.00 0.00 0.00
Theoretical Velocity (ft/s): 2.77 3.91 0.00 0.00 0.00 0.00 0.00 0.00 0.00
Reduction Factor: 0.80 0.80 -0.10 -0.10 -0.10 -0.10 -0.10 -0.10 -0.10
Allowable Capacity (cfs): 5.69 8.04 0.00 0.00 0.00 0.00 0.00 0.00 0.00
Q2 1.15 1.30 2.86 1.89 0.71 1.29 1.05 1.67 1.32
Crowne @ Old Town North
501-003
The Sear-Brown Group
10:09 PM
2/13/2017
26
APPENDIX E
27
SWALE SIZING
(TO BE PROVIDED AT FINAL DESIGN)
28
APPENDIX F
29
EROSION CONTROL & RIPRAP
SIZING & EROSION CONTROL
ESCROW ESTIMATE
(TO BE PROVIDED AT FINAL DESIGN)
30
APPENDIX G
31
PROPOSED & EXISTING DRAINAGE
BASIN EXHIBITS, EROSION
CONTROL PLAN, & EROSION
CONTROL NOTES AND DETAILS
SHEET