HomeMy WebLinkAboutFORT COLLINS VETERINARY EMERGENCY & REHABILITATION HOSPITAL - FDP - FDP130038 - SUBMITTAL DOCUMENTS - ROUND 1 - DRAINAGE REPORTFINAL DRAINAGE AND EROSION
CONTROL STUDY
FORT COLLINS VETERINARY EMERGENCY
HOSPITAL & REHABILITATION CLINIC
Prepared for:
Hauser Architects
3780 E 15th St, Ste 201
Loveland, CO 80538
970-669-8220
Prepared by:
North Star Design, Inc.
700 Automation Drive, Unit I
Windsor, Colorado 80550
(970) 686-6939
September 26, 2013
Job Number 346-01
ii
September 26, 2013
Glen Schlueter
City of Fort Collins Stormwater
700 Wood Street
Fort Collins, CO 80522-0580
RE: Final Drainage and Erosion Control Study for Fort Collins Veterinary
Emergency Hospital & Rehabilitation Clinic
Dear Glen,
I am pleased to submit for your review and approval, this Final Drainage and Erosion Control
Study for the Fort Collins Veterinary Emergency Hospital & Rehabilitation Clinic located at 816
Lemay Avenue and the proposed expansion onto 808 Lemay Avenue. I certify that this report
for the drainage design was prepared in accordance with the criteria in the City of Fort Collins
Storm Drainage Manual.
I appreciate your time and consideration in reviewing this submittal. Please call or email if you
have any questions or require clarifications.
Sincerely,
Patricia Kroetch, P.E.
700 Automation Drive, Unit I
Windsor, CO 80550
Phone: 970-686-6939
Fax: 970-686-1188
iii
TABLE OF CONTENTS
TABLE OF CONTENTS ............................................................................................................... iii
1. GENERAL LOCATION AND DESCRIPTION
1.1 Location ...................................................................................................................1
1.2 Description of Property ............................................................................................1
2. DRAINAGE BASINS AND SUB-BASINS
2.1 Major Basin Description ..........................................................................................2
2.2 Sub-Basin Description .............................................................................................2
3. DRAINAGE DESIGN CRITERIA
3.1 Regulations ..............................................................................................................2
3.2 Development Criteria Reference and Constraints ...................................................2
3.3 Hydrologic Criteria ..................................................................................................2
3.4 Hydraulic Criteria ....................................................................................................3
4. DRAINAGE FACILITY DESIGN
4.1 General Concept ......................................................................................................3
4.2 Specific Flow Routing .............................................................................................3
4.3 Drainage Summary ..................................................................................................4
5. STORMWATER MANAGEMENT CONTROLS
5.1 Written Analysis .....................................................................................................4
5.2 SWMP Contact Information ...................................................................................5
5.3 Identification and location of all potential pollution sources ..................................6
5.4 Best Management Practices (BMP’s) for Stormwater Pollution Prevention ...........6
5.5 BMP Implementation .............................................................................................10
6. CONCLUSIONS
6.1 Compliance with Standards ..................................................................................13
6.2 Drainage Concept ..................................................................................................13
7. REFERENCES ..................................................................................................................14
APPENDICES
A Vicinity Map
B Hydrologic Computations
C Excerpts from Previous Reports
1
1. GENERAL LOCATION AND DESCRIPTION
1.1 Location
The existing Fort Collins Veterinary Emergency Hospital & Rehabilitation Clinic (Vet
Clinic) site is located on Lot 2, 800 Lemay Properties and the proposed expansion is
located on Lot 1, Lemay Ltd First Subdivision. This project is located in Section 18,
Township 7 North, Range 68 West of the Sixth Principal Meridian, in the City of Fort
Collins, Larimer County, Colorado. See the location map in Appendix A.
The project is located east of Lemay Avenue between Riverside Avenue and Elizabeth
Street. The project is bounded on all sides by existing commercial & retail development.
1.2 Description of Property
The entire site (both lots) consists of approximately 0.6 acres of land. The site at 816
Lemay is currently developed with asphalt drives and parking and a building that
contains the existing Vet Clinic. The site at 808 Lemay is currently developed with a car
wash building, a storage building, asphalt drives and parking. A majority of the existing
asphalt will be preserved with some reconfiguration to allow the site to meet minimum
parking setbacks. The existing care wash building will be demolished and the storage
building and vet clinic building will be preserved. Sidewalks on site will also be
reconfigured to accommodate the new parking and new building and to meet the arterial
street standards and provide a parkway. The existing site at 816 Lemay currently drains
to the parking lot to a flow path in the asphalt which conveys the runoff to Lemay
through the drive access. The existing site at 808 Lemay currently drains to the shared
private drive on the north boundary of the site and flows east into an existing detention
pond which releases into an existing area inlet. None of the site appears to drain onto the
adjacent properties.
The site will continue to generally drain in the existing flow paths. The runoff from the
site at 816 Lemay will be routed through a grassed swale prior to entering Lemay
Avenue. The proposed development will reduce the amount of imperviousness and will
therefore reduce the amount of anticipated runoff. No additional detention is proposed
for this site.
3
2. DRAINAGE BASINS AND SUB-BASINS
2.1 Major Basin Description
The proposed development lies within the Old Town Drainage Basin.
2.2 Sub-basin Description
This site (800 Lemay) is included in the drainage calculations for “800 Lemay Carwash
and Tunex” by Stewart & Associates dated July 15, 1986, included in Appendix C of this
report.
3. DRAINAGE DESIGN CRITERIA
3.1 Regulations
This report was prepared to meet or exceed the “City of Fort Collins Storm Drainage
Design Criteria Manual” specifications. Where applicable, the criteria established in the
“Urban Storm Drainage Criteria Manual” (UDFCD), 1984, developed by the Denver
Regional Council of Governments, has been used.
3.2 Development Criteria Reference and Constraints
The runoff from this site has been routed to maintain the existing drainage patterns on
site. The Old Town Basin is normally required to detain to the 2 year historic runoff rate
but, because there is no increase in imperviousness proposed on this site, no detention
will be provided with this development.
3.3 Hydrologic Criteria
Runoff computations were prepared for the 10-year minor and 100-year major storm
frequency utilizing the rational method.
All hydrologic calculations associated with the basins are included in Appendix B of this
report. Standard Form 8 (SF-8) provides time of concentration calculations for all sub-
4
basins. Standard Form 9 (SF-9) provides a summary of the design flows for all Sub-
basins and Design Points associated with this site.
3.4 Hydraulic Criteria
No hydraulic calculations were completed for this site because the amount of runoff from
this site will not increase. It is assumed that the existing storm conveyances currently
operate adequately in storm events and this development will not impact the existing
operation.
4. DRAINAGE FACILITY DESIGN
4.1 General Concept
The runoff from this site will be collected in the flowpath in the asphalt and be conveyed
to Lemay Avenue or to the existing detention pond and inlet in the northeast corner of the
site. No runoff from this site will impact the adjacent properties.
4.2 Specific Flow Routing
A summary of the drainage patterns within each basin is provided in the following
paragraphs.
Basin 1 encompasses the majority of the lot at 816 South Lemay Avenue and the existing
Vet Clinic building. Very minor changes will be made to this lot and will include the
removal of some existing parking adjacent to Lemay to meet the parking setbacks. The
existing flow path is in the center of the asphalt which conveys runoff west and into
Lemay Avenue. A majority of this asphalt and flowpath will remain but runoff from this
lot will be routed through a grassed swale prior to entering Lemay in the historic manner.
This will provided some opportunity for the runoff from the site to have sediment
removal. The amount of asphalt will be reduced, therefore the amount of runoff will be
reduced.
Basin 2 includes the majority of the lot at 808 South Lemay Avenue which is the existing
carwash to be demolished. The building expansion will be located on this lot and the
existing parking lot will be reconfigured. Runoff from this basin historically flows to an
existing detention pond in the northeast corner of the lot located in the parking lot. This
5
detention pond will be maintained and all runoff from the site will continue to flow to
this detention area. The amount of imperviousness in this basin will also be reduced,
therefore the amount of runoff anticipated will also be reduced with this proposed
redevelopment.
Basin 3 includes a small area along the west boundary of 808 South Lemay that will
drain directly to Lemay Avenue as it has historically done. The majority of this basin is
landscape area.
4.3 Drainage Summary
All runoff from this site and the adjacent sites will be safely conveyed via surface flow to
the street or existing storm system. The site will maintain the drainage patterns that
currently exist on site.
The City of Fort Collins will be responsible for maintenance of the existing storm
drainage facilities located within the right-of-way. The drainage facilities located on the
site will be maintained by the property owner.
5. STORMWATER MANAGEMENT CONTROLS
5.1 Written Analysis
The soils on this site are classified by the USGS Soil Survey as Santana Loams and are
classified in the hydrologic group B. The soils are described as being well drained and
having a moderately high to high ability to transmit water (0.6 to 2.0 inches per hour).
The rainfall and wind erodibility is deemed to be moderate.
The site is surrounded by developed sites including streets and paved areas. The
construction shall utilize silt fence around the west and south perimeter to control
sediment transport from rainfall and from wind. Existing pavement on the north and east
boundaries is to remain. Rock socks will be utilized in the existing curb and around the
existing inlet in Basin 1 to capture sediments that are not fully contained by the silt fence
placement. The locations of the rock socks will be in the areas of concentrated flow such
as the existing curb, existing inlet and on the existing concrete sidewalks.
6
The site may also utilize a vehicle tracking control pad to minimize sediment from being
tracked onto adjacent pavements. Sediment that is tracked will be removed and placed
within the site or permanently disposed of offsite. A concrete washout will be used on
site during the concrete placement. All hardened concrete will be disposed of offsite.
These BMP’s have not been located on the site map due to the fact that the site is very
small and these BMP’s will need to be placed by the contractor in locations that are most
beneficial and will minimize disruption of adjacent traffic.
Permanent erosion control consists of covering the soils with a building, concrete walks,
concrete drives and sod. No soil will be left exposed to erosion after the construction is
complete. Refer to the landscape plan for areas of and instructions for placement of sod
and soil amendments required prior to placement of sod.
Refer to section 5.5 for the timing of the construction phases and the sequential
installation of all BMP phasing for this site.
Refer to the end of Section 5.4 for the Erosion Control Surety calculations.
5.2 SWMP contact information
Permit holder:
Name:
Address:
Phone Number:
Email Address:
Appointed agent:
Name:
Address:
Phone Number:
Email Address:
7
5.3 Identification and location of all potential pollution sources
Potential Pollutant Source Activity Potential Pollutant Generated Applicable to
this project
Disturbed Areas Sediment X
Soil stockpiles Sediment X
Travel to adjacent public streets Tracked sediment X
Contaminated soils Sediment, chemicals
Loading and unloading chemicals Chemicals
Outdoor storage of chemicals Chemicals
On site equipment maintenance Oil, grease
On site equipment fueling Diesel, gasoline X
Dust generating activities Particulates, sediment X
Use of fertilizer, pesticides, herbicides Fertilizer, pesticides
Use of detergents, solvents, oils Detergents, solvents, oil X
Waste dumpsters, waste piles Chemicals X
Concrete washout Concrete, sediment X
On site equipment washing Detergents, oil
On site asphalt batch plant Asphaltic cement, sediment
On site concrete batch plant Cement, sediment
Portable toilets Domestic sewage X
5.4 Best Management Practices (BMP’s) for Stormwater Pollution Prevention
Structural Practices for Erosion and Sediment Control
Structural practices for the site will consist mainly of silt fence and rock sock filters and are
described in detail in the following paragraphs. These BMP's are expected to change as the
construction progresses and it is the responsibility of the contractor to ensure appropriate BMP's
are in place and/or removed at the appropriate time in the construction sequence. All temporary
and permanent erosion and sediment control practices must be maintained and repaired as
needed to assure continued performance of their intended function.
Silt fence and rock sock filters shall be in place prior to commencement of construction
activities. During clearing and grubbing necessary for silt fence installation, all cleared material
shall be placed on the uphill side so that if erosion occurs from the cleared material, the sediment
will be trapped and not transported downstream. Rock socks shall be implemented in the existing
curb line as shown on the Drainage & Erosion Control Plan.
8
All BMP's shall be installed per the details shown on the construction plan set.
Temporary & Permanent Structural BMP’s:
Structural BMP Approximate location on site Applicable to this
Project
Silt Fence Site perimeter, refer to site map X
Straw bale dams
Rock Socks At proposed sidewalk culverts, refer to site
map X
Earthen diversion dams
Vegetated swales
Sediment trap/pond
Pipe slope drains
Geogrid
Inlet/outlet protection
Culverts
Riprap
Erosion control mats
Inlet protection X
Non-Structural Practices for Erosion and Sediment Control:
Soils exposed during the earthwork phase and landscape prep phase shall be kept in a roughened
condition by ripping or disking along land contours until mulch, vegetation, or other permanent
erosion control is installed. No large amount of soils (in excess of 15 yards) will be allowed to be
stock piled on site. Overburden from the utility pipe trenching will be piled adjacent to trenches
upstream of sediment controls and will be replaced in the trenches within 72 hours.
Excess excavated materials from the demolition and grading phases of the project that cannot be
reused on site will be exported as it is excavated. This includes any asphalt pavement from the
existing site that is to be removed.
A vehicle tracking pad will be installed at a location most beneficial to the site construction as
determined by the contractor. Vehicles will not be permitted in the excavated area if soil is
muddy. Gravel sub base will be placed and compacted in the areas indicated for pavement
following excavation. In the current pre construction state the site enables tracking of silt onto
the adjacent streets during wet conditions. During construction activities the street will be
monitored for foreign debris tracked out of the site and mechanical sweeping and clean up will
be performed as needed.
9
No area shall remain exposed by land disturbing activity for more than thirty (30) days before
required temporary or permanent erosion control (e.g. seed/mulch, landscaping, etc.) is installed.
Temporary & Permanent non-structural BMP’s:
Non-Structural BMP Approximate location on site Applicable to this
Project
Surface roughening Entire site X
Soil stockpile height limit (less
than 10’)
Perimeter vegetative buffer South and west boundary of site X
Minimization of site disturbance
Mulch
Seed & mulch stockpiles after 30
days
Stockpile toe protection (silt fence,
wattles or ditch)
Preservation & protection of
existing vegetation & trees South boundary of site X
Good site housekeeping (routine
cleanup of trash & constr debris) Entire Site X
Heavy equip staged on site,
properly maintained & inspected
daily (no onsite maintenance)
Staging area X
Quantity Cost
1 CDR LF $0.00
2 CDR LF $0.00
3 CWA EA 1 $1,200.00
4 CF LF $0.00
5 CM LF $0.00
6 CIF LF $0.00
7 DW EA $0.00
8 DD LF $0.00
9 DD LF $0.00
10 ECM SY $0.00
11 IP LF 12 $120.00
12 RRB LF $0.00
13 SB LF $0.00
14 SCL LF 15 $69.00
15 SM AC $0.00
16 SF LF 250 $750.00
17 RS LF 30 $300.00
18 SSA SY $0.00
19 SR AC $0.00
20 TSC EA $0.00
21 TSL AC $0.00
22 VTC EA 1 $1,500.00
$3,939.00
$590.85
$4,529.85
$1,500.00
Maintenance & replacements (15%)
$4.60
$3.00
$10.00
Construction Fence
Vehicle Tracking Control (2)
Topsoil (6-inch Lift)
Temporary Stream Crossing
Surface Roughening
Stabilized Staging Area
$10.00
Construction Markers
Culvert Inlet Filter
Dewatering
Diversion Ditch (Unlined)
Diversion Ditch (ECM or plastic)
Sediment/Erosion Control Matting
Inlet Protection
Reinforced Rock Berm
Sediment Basin
(1)
Rock Sock
Silt Fence
Seeding and Mulching
Sediment Control Log (Wattle)
Item
No.
Check Dam (Reinforced)
Concrete Washout Area
Check Dam
SEDIMENT/EROSION CONTROL
BEST MANAGEMENT PRACTICES (BMPs)
COST OPINION SPREADSHEET
11
5.5 BMP Implementation
1) Phased BMP Implementation
BMP’s are expected to change as the construction progresses and it is the responsibility
of the contractor to ensure appropriate BMP’s are in place and/or removed at the
appropriate time in the construction sequence. All BMP’s shall be inspected and
repaired or replaced as required to satisfy the conditions of the Stormwater Discharge
Permit. All BMP’s must be maintained and repaired as needed to assure continued
performance of their intended function.
The following phase depictions and erosion controls are suggestions to the contractor only
and are in no way intended to dictate construction phasing or control of the work on site.
The contractor shall be responsible to control construction phasing and provide adequate
erosion control associated with each phase in order to comply with the SWM Plan and
Permit that is obtained by the contractor (or owner) for the site.
Phase 1 – Mobilization
Install silt fence, Install rock socks, set dumpster.
Phase 2 – Site demolition, Overlot Grading
Demolish existing car wash, Clear existing asphalt that is to be removed. Complete minor
cut and fill on site to achieve subgrade elevations
Phase 3 - Utilities
Excavate and install for water service and sewer service modification, excavate and
install dry utilities.
Phase 4 – Install Concrete Foundation
Establish temporary concrete washout area, cut for building foundation, place
concrete foundation. Install concrete curb & gutter. Remove concrete wash out.
Phase 5 –Site Paving
Install sub base, install asphalt pavement.
Phase 6 – Building construction
Complete vertical building construction
Phase 7 – Landscape installation
Final shaping of planting areas, Install irrigation system, Install soil amendments,
Landscape plant installation, Install mulch ground cover
Phase 8 – Final Stabilization
Final stabilization is complete when constructed improvements are in place, Inspect
completed construction for possible sources of erosion and amend the plan as required to
trap sediments.
12
2) Materials Handling and Spill Prevention:
Materials Handling & Spill
Prevention BMP Approximate location on site
Applicable to this
Project
Portable toilets, anchored &
located away from drainages Contractor to determine X
Fuel storage located in bulk tanks
with secondary containment &
spill kit
Mobile fueling performed at least
200 feet away from drainages &
fully attended
Contractor to determine X
Fertilizers, form oil, solvents,
cleaners, detergent stored in 55 gal
or smaller containers, kept in
storage units
Contractor to determine X
Dumpsters containing used
chemicals containers & liquid
wastes kept covered
Contractor to determine X
Equipment cleaning (on site) uses
no detergents & flows to onsite
retention basin
In case of a release of fuel or other
chemicals, absorbent booms or
earthen berms will be immediately
constructed to contain the spill &
prevent runoff to adjacent surface
waters
Location of spill X
MSDS sheets for onsite chemicals
will be kept at the construction
trailer to facilitate spill response &
cleanup
Construction trailer X
3) Dedicated Asphalt or Concrete Batch Plant:
Not proposed with this development.
4) Vehicle Tracking Pad:
Vehicle tracking control pad shall be installed wherever construction vehicle access
routes intersect paved public roads. Vehicle tracking control pads shall be installed to
13
minimize the transport of sediment (mud) by runoff or vehicles tracking onto the paved
surface. Any mud tracked to public roads shall be removed on a daily basis and after
any significant storm that causes sediment to be transported.
It is unlawful to track sediment/mud onto public streets and may be enforced by the City
of Fort Collins or by the State of Colorado.
5) Waste Management and Disposal:
Portable toilets will be anchored & periodically maintained by waste management
company. Dumpsters on site will be covered & periodically emptied by waste
management company. Concrete waste will be allowed to harden and then will be
removed from site.
No washing activities will occur on site.
Location of the concrete washout will be determined by the contractor. The washout
will be sufficiently deep to accommodate all anticipated concrete truck wash water.
Waste concrete will be allowed to harden and be removed from site periodically as the
washout reaches 50% of its capacity. Truck wash water will not be allowed to reach the
curb & gutter or any other water course.
6) Groundwater and Stormwater Dewatering:
No groundwater encountered during soils exploration
therefore not anticipated to be an issue.
If groundwater is encountered a groundwater discharge permit shall be obtained and a
detailed report shall be completed describing the location and the route of where
pumped groundwater will be conveyed and the measures taken to prevent the transport
of any pollutants to downstream waters.
7) Inspection & Maintenance:
14
It is required that routine site inspections are performed to effectively address maintenance and
repair of Best Management Practices (BMP's). The site inspections are to performed by the
contractor or an inspector designated by the administrator at a minimum of once every fourteen
(14) calendar days on active construction sites and after any significant storm event (an event
causing runoff). As part of the site inspections the inspector is required to keep documentation of
all inspections and BMP maintenance, including an updated Site Map indicating new BMP's or
the removal of BMP's since the previous inspection.
Any maintenance, repair, or necessary installation of BMP's that are noted during the inspection
must be completed within seven (7) calendar days from the date of the inspection.
6. CONCLUSIONS
6.1 Compliance with Standards
All computations that have been completed within this report are in compliance with the
City of Fort Collins Storm Drainage Design Criteria Manual and the drainage
calculations for 800 Lemay Carwash and Tunex.
6.2 Drainage Concept
The proposed drainage concepts presented in this report and on the construction plans
adequately provide for conveyance of runoff to the street or existing storm system. No
new storm conveyances are proposed on site.
If, at the time of construction, groundwater is encountered, a Colorado Department of
Health Construction Dewatering Permit would be required.
15
7. REFERENCES
1. City of Fort Collins, “Storm Drainage Criteria Manual”, (SDCM), dated June,
2001 and Ordinance 174 adopted in December 2011.
2. Urban Drainage and Flood Control District, “Urban Storm Drainage Criteria
Manual”, Volumes 1 and 2, dated March, 1969, and Volume 3 dated September,
1992.
3. Old Town Master Drainage Plan Update by Anderson Consulting currently in
progress.
4. Drainage calculations for 800 Lemay Carwash and Tunex dated July 15, 1986 by
Stewart & Associates.
A
APPENDIX A
VICINITY MAP
B
APPENDIX B
HYDROLOGIC COMPUTATIONS
North Star Design, Inc.
700 Automation Drive, Unit I
Windsor, CO 80550
LOCATION: FC Vet Hospital
PROJECT NO: 346-01
COMPUTATIONS BY: PPK
DATE: 6/28/2013
Recommended % Impervious from Urban Storm Drainage Criteria Manual
%
Impervious
Roofs: 90%
Streets and Parking (Asphalt) 100%
Concrete Drives and Walks 90%
Packed Gravel: 40%
Landscaped Areas (Clayey soil, 0-1% slopes): 0%
SUBBASIN TOTAL TOTAL ROOF ASPHALT CONCRETE GRAVEL LANDSCAPE % RUNOFF RUNOFF RUNOFF RUNOFF
ID AREA AREA AREA AREA AREA AREA AREA Impervious COEFF. COEFF. COEFF. COEFF.
(ac.) (sq.ft) (sq.ft) (sq.ft) (sq.ft) (sq.ft) (sq.ft) C2 C5 C10 C100
EX 1 0.21 9,026 2,880 5,349 216 0 581 90% 0.73 0.75 0.78 0.84
EX 2 0.31 13,620 2,254 8,630 218 0 2,518 80% 0.59 0.62 0.66 0.74
EX 3 0.03 1,224 0 156 0 0 1,068 13% 0.13 0.13 0.13 0.13
DEV 1 0.21 9,026 2,532 4,450 138 0 1,906 76% 0.55 0.58 0.62 0.71
DEV 2 0.31 13,620 4,390 5,695 343 0 3,192 73% 0.52 0.56 0.60 0.70
DEV 3 0.03 1,224 0 136 72 0 1,016 16% 0.15 0.15 0.15 0.15
RUNOFF COEFFICIENTS & % IMPERVIOUS
Flow site.xls Cval
North Star Design, Inc.
700 Automation Drive, Unit I
Windsor, CO 80550
LOCATION: FC Vet Hospital
PROJECT NO: 346-01
COMPUTATIONS BY: PPK
DATE: 6/28/2013
SUB-BASIN DATA INITIAL / OVERLAND TIME TRAVEL TIME / GUTTER OR CHANNEL FLOW tc CHECK FINAL REMARKS
(ti)(tt) (URBANIZED BASIN) tc
DESIGN SUBBASIN Area C5 Length Slope ti Length Slope Chan. Cv Vel. tt tc = Total L tc=(l/180)+10
POINT ID (ac) (ft) (ft/ft) (min) (ft) (ft/ft) Type (ft/s) (min) ti + tt (ft) (min) (min)
(1) (2) (3) (4) (5) (6) (7) (8) (9) (10) (11) (12) (13) (14)
EX 1 EX 1 0.21 0.75 15 0.020 2.0 155 0.013 F 20 2.3 1.1 3.1 170 10.9 5.0
EX 2 EX 2 0.31 0.62 32 0.010 4.9 170 0.005 F 20 1.4 2.0 7.0 202 11.1 7.0
EX 3 EX 3 0.03 0.13 12 0.010 6.2 12 0.010 F 20 2.0 0.1 6.3 24 10.1 6.3
DEV 1 DEV 1 0.21 0.58 15 0.020 2.9 155 0.013 F 15 1.7 1.5 4.4 170 10.9 5.0
DEV 2 DEV 2 0.31 0.56 32 0.010 5.6 170 0.005 F 20 1.4 2.0 7.6 202 11.1 7.6
DEV 3 DEV 3 0.03 0.15 12 0.010 6.0 12 0.010 F 20 2.0 0.1 6.1 24 10.1 6.1
EQUATIONS: Channel Type Cv
tc = t
i + tt
A 2.5
B 5.0
ti = [0.395 (1.1 - C
5 ) L
0.5
] / S
1/3
C 7.0
D 10.0
tt = L/V V = C
v*S
0.5
E 15.0
F 20.0
final tc = minimum of t
i + tt
and urbanized basin check
minimum tc = 5 minutes
TIME OF CONCENTRATION
Paved
Grassed Waterway
Bare Ground
Short Pasture/ Lawn
Tillage / Field
Heavy Meadow
Flow site.xls TOC5
North Star Design, Inc.
700 Automation Drive, Unit I
Windsor, CO 80550
LOCATION: FC Vet Hospital
PROJECT NO: 346-01
COMPUTATIONS BY: PPK
DATE: 6/28/2013
DIRECT RUNOFF TOTAL Inlet Capacity REMARKS
DESIGN SUBBASIN A C2 tc iQ2 Q2 Total
POINT ID
(ac) (min) (in/hr) (cfs) (cfs) (cfs)
EX 1 EX 1 0.21 0.73 5.0 2.85 0.43 0.4 to Lemay
EX 2 EX 2 0.31 0.59 7.0 2.52 0.47 0.5 To existing pond
EX 3 EX 3 0.03 0.13 6.3 2.68 0.01 0.0 To Lemay
DEV 1 DEV 1 0.21 0.55 5.0 2.85 0.32 0.3 to Lemay
DEV 2 DEV 2 0.31 0.52 7.6 2.37 0.39 0.4 To existing pond
DEV 3 DEV 3 0.03 0.15 6.1 2.71 0.01 0.0 To Lemay
Q = C i A
Q = peak discharge (cfs)
C = runoff coefficient
i = rainfall intensity (in/hr) from IDF curve
A = drainage area (acres)
RATIONAL METHOD PEAK RUNOFF
(2-YEAR)
Flow site.xls Q2
North Star Design, Inc.
700 Automation Drive, Unit I
Windsor, CO 80550
LOCATION: FC Vet Hospital
PROJECT NO: 346-01
COMPUTATIONS BY: PPK
DATE: 6/28/2013
DIRECT RUNOFF TOTAL Inlet Capacity REMARKS
DESIGN SUBBASIN A C10 tc iQ10 Q10 Total
POINT ID
(ac) (min) (in/hr) (cfs) (cfs) (cfs)
EX 1 EX 1 0.21 0.78 5.0 4.87 0.78 0.8 to Lemay
EX 2 EX 2 0.31 0.66 7.0 4.31 0.89 0.9 To existing pond
EX 3 EX 3 0.03 0.13 6.3 4.51 0.02 0.0 to Lemay
DEV 1 DEV 1 0.21 0.62 5.0 4.87 0.63 0.6 to Lemay
DEV 2 DEV 2 0.31 0.60 7.6 4.05 0.76 0.8 To existing pond
DEV 3 DEV 3 0.03 0.15 6.1 4.52 0.02 0.0 to Lemay
Q = C i A
Q = peak discharge (cfs)
C = runoff coefficient
i = rainfall intensity (in/hr) from IDF curve
A = drainage area (acres)
RATIONAL METHOD PEAK RUNOFF
(10-YEAR)
Flow site.xls Q10
North Star Design, Inc.
700 Automation Drive, Unit I
Windsor, CO 80550
LOCATION: FC Vet Hospital
PROJECT NO: 346-01
COMPUTATIONS BY: PPK
DATE: 6/28/2013
DIRECT RUNOFF TOTAL Inlet Capacity REMARKS
DESIGN SUBBASIN A C100 t
c iQ100
Q100 Total
POINT ID
(ac) (min) (in/hr) (cfs) (cfs) (cfs)
EX 1 EX 1 0.21 0.84 5.0 9.95 1.72 1.7 to Lemay
EX 2 EX 2 0.31 0.74 7.0 8.80 2.04 2.0 To existing pond
EX 3 EX 3 0.03 0.13 6.3 9.51 0.03 0.0 to Lemay
DEV 1 DEV 1 0.21 0.71 5.0 9.95 1.47 1.5 to Lemay
DEV 2 DEV 2 0.31 0.70 7.6 8.27 1.80 1.8 To existing pond
DEV 3 DEV 3 0.03 0.15 6.1 9.24 0.04 0.0 to Lemay
Q = C i A
Q = peak discharge (cfs)
C = runoff coefficient
i = rainfall intensity (in/hr) from IDF curve
A = drainage area (acres)
RATIONAL METHOD PEAK RUNOFF
(100-YEAR)
Flow site.xls Q100
C
APPENDIX C
EXCERPTS FROM PREVIOUS REPORTS
This unofficial copy was downloaded on Apr-27-2013 from the City of Fort Collins Public Records Website: http://citydocs.fcgov.com
For additional information or an official copy, please contact City of Fort Collins Utilities 700 Wood Street Fort Collins, CO 80524 USA
This unofficial copy was downloaded on Apr-27-2013 from the City of Fort Collins Public Records Website: http://citydocs.fcgov.com
For additional information or an official copy, please contact City of Fort Collins Utilities 700 Wood Street Fort Collins, CO 80524 USA
This unofficial copy was downloaded on Apr-27-2013 from the City of Fort Collins Public Records Website: http://citydocs.fcgov.com
For additional information or an official copy, please contact City of Fort Collins Utilities 700 Wood Street Fort Collins, CO 80524 USA
This unofficial copy was downloaded on Apr-27-2013 from the City of Fort Collins Public Records Website: http://citydocs.fcgov.com
For additional information or an official copy, please contact City of Fort Collins Utilities 700 Wood Street Fort Collins, CO 80524 USA
BMP ID
Installation
Unit Unit Cost
FORT COLLINS VETERINARY CLINIC & EMERGENCY HOSPITAL
g
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Erosion control escrow amount
Subtotal
$1,200.00