HomeMy WebLinkAboutFEEDER SUPPLY - FDP - FDP130039 - SUBMITTAL DOCUMENTS - ROUND 1 - DRAINAGE REPORTFINAL DRAINAGE AND EROSION
CONTROL REPORT
FEEDER SUPPLY PROJECT
PRELIMINARY DRAINAGE AND EROSION
CONTROL REPORT
FEEDER SUPPLY PROJECT
Prepared for:
Jon Prouty
Lagunitas
Fort Collins, CO 80216
Prepared by:
North Star Design
700 Automation Drive, Unit I
Windsor, Colorado 80550
(970) 686-6939
October 4, 2013
Job Number 173-10
October 4, 2013
Glen Schlueter
City of Fort Collins Stormwater
700 Wood Street
Fort Collins, CO 80522
RE: Drainage and Erosion Control Report for Feeder Supply Project
Dear Glen,
I am pleased to submit for your review and approval, this Drainage & Erosion Control Report for
the Feeder Supply project. I certify that this report for the drainage design of the Feeder supply
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 if you have any
questions.
Prepared by:
Patricia Kroetch P.E.
Project Manager
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
1.3 Major Basin Description ..........................................................................................2
1.4 Sub Basin Description .............................................................................................2
2. DRAINAGE DESIGN CRITERIA
2.1 Regulations ..............................................................................................................2
2.2 Development Criteria Reference and Constraints ...................................................2
2.3 Hydrologic Criteria ..................................................................................................3
2.4 Hydraulic Criteria ....................................................................................................3
3. DRAINAGE FACILITY DESIGN
3.1 General Concept ......................................................................................................3
3.2 Specific Flow Routing .............................................................................................3
3.3 Drainage Summary ..................................................................................................4
4. STORM WATER MANAGEMENT CONTROLS
4.1 Written Analysis .....................................................................................................4
4.2 SWMP contact information .....................................................................................5
4.3 Identification and location of all potential pollution sources ..................................6
4.4 Best Management Practices (BMP’s) for Stormwater Pollution Prevention ...........6
4.5 BMP Implementation .............................................................................................10
5. CONCLUSIONS
5.1 Compliance with Standards ..................................................................................13
5.2 Drainage Concept ..................................................................................................13
6. REFERENCES ..................................................................................................................14
APPENDICES
A Vicinity Map
B Hydrologic Computations
C Hydraulic Computations
1
1. GENERAL LOCATION AND DESCRIPTION
1.1. Location
The Feeder Supply redevelopment project, hereafter referred to as the Feeder Supply, is
located at 359 Linden. The proposed project is located on a portion of Blocks 6 & 7, City
of Fort Collins Old Town in the Northeast Quarter of Section 12, Township 7 North,
Range 69 West of the Sixth Principal Meridian, in the City of Fort Collins, Larimer
County, Colorado. See the location map in Appendix A.
This project is bounded on the northeast by Willow Street, on the southeast by Linden
Street, on the northwest by Schrader Oil Company, and on the southwest by existing
office and commercial development.
1.2. Description of Property
The project consists of approximately 1.4 acres of land. There is currently one original
historic building on site that has several additions which were added after the original
building and gravel drives and parking. There is no existing vegetation on site. The
original historic building will be preserved and the additions will be removed with this
project. The original building will be expanded and an additional residential and retail
building with parking on the main floor will be located northwest of the existing structure
that will remain. Willow Street will be widened with this project and internal drives and
parking will be paved with asphalt.
All elevations given in this report and in the construction plans are based on the 1929
NGVD unadjusted datum. See the grading sheet for specific elevations on the site and
elevation of the building at each entry point.
Stormwater from the Cache La Poudre Drainage Basin is ultimately routed to the Poudre
River in the existing streets and existing storm pipes in historic flow routes. Runoff from
this site will flow to a storm pipe that will be relocated with this project. This storm
system will convey the runoff to an existing inlet at the intersection of Willow and
Linden. From this point the runoff will be routed through a Bay Saver water quality
structure and into a regional detention facility. Because of this, no on site detention is
being provided.
2
Currently water quality and detention measures have not been provided for the existing
development. With this project, it is proposed to construct approximately 22,000 sq.ft of
additional roof area, 16,600 sq. ft. of additional asphalt pavement area and no
additional concrete area. The original development (historic condition) had
approximately 5230 square feet of roof area, 1760 square feet of concrete and no asphalt.
The entire site (except for the building area that will remain) is expected to undergo
clearing, excavating and grading. Since there additional impervious area being
constructed, water quality and detention would normally be required for the new
impervious area. With this project the City will allow the runoff from the site to enter the
existing storm system without detention because detention for this area is provided in a
regional facility downstream.
Even though the runoff from the site is directed through a Bay Saver water quality
structure, additional water quality enhancement is proposed for site in the form of water
quality enhancement (L.I.D.) swales and approximately 3500 square feet of porous
concrete.
1.3. Major Basin Description
This site is located in the Cache La Poudre Drainage Basin and all runoff from the site
will reach the Poudre River. The site is not located within the FEMA designated 100 year
floodplain or the City designated flood plain.
1.4. Sub-basin Description
The majority of the site will be collected in an onsite L.I.D. and storm system and
conveyed to the existing inlet located at the intersection of Willow and Linden. A small
portion of the entry drives will directly enter the adjacent streets and flow in the streets to
the same storm system. See Section 3 of this report for specific details.
2. DRAINAGE DESIGN CRITERIA
2.1. Regulations
Drainage for this site has been designed to meet or exceed the “City of Fort Collins
Stormwater Criteria Manual” specifications, the City of Fort Collins Cache la Poudre
Basin Master Plan and the update to Chapter 26 of the City Code. Where applicable, the
criteria established in the “Urban Storm Drainage Criteria Manual” (UDFCD), 2001 has
been used.
3
2.2. Development Criteria Reference and Constraints
Stormwater runoff from this site has been routed to conform to the requirements of the
City Stormwater Department. Detention would normally be required for this site but
because the runoff will enter the storm system and be conveyed to a regional facility,
detention will not be provided.
Water quality facilities are required for the improvements and are being provided by an
existing off site Bay Saver water quality structure, 3500 square feet of porous concrete
and proposed water quality swales (LID) on the site. These water quality enhancement
measures serve to meet the City criteria for new developed runoff.
2.3. Hydrologic Criteria
Runoff computations were prepared for the 2 year and 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.
2.4. Hydraulic Criteria
Hydraulic calculations for the onsite storm pipes are provided in the appendix and were
prepared in accordance with the City of Fort Collins Drainage Criteria and the Urban
Area Drainage Criteria Manual.
3. DRAINAGE FACILITY DESIGN
3.1. General Concept
All of the runoff from this site historically sheet flows to the adjacent streets and is
intercepted by the existing inlets located in Willow and Linden Streets. With the
construction of these proposed improvements, onsite stormwater will be collected in an
onsite storm and LID system and conveyed to the existing storm system in Willow Street.
3.2. Specific Flow Routing
Basin 1 encompasses the entire site. This basin includes a majority of the asphalt drives
on site and all of the buildings (existing and proposed) on site. Improvements proposed
in the right of way for Willow or existing improvements along Linden are not included in
this basin. Runoff from this basin will sheet flow to proposed 4’ concrete pans on site
and into a proposed L.I.D. swale or into a storm inlet. Roof runoff will be collected in an
4
onsite storm system and piped to the relocated storm system in Willow. Water quality is
provided for this basin by the L.I.D. swales, porous concrete and a downstream Bay
Saver structure.
3.3. Drainage Summary
Drainage for this site was designed to conform to the City of Fort Collins stormwater and
water quality requirements. Water quality is provided for a majority of the site utilizing
water quality swales and porous concrete. Water quality for the site is also provided by
routing runoff through a Bay Saver sediment trap downstream.
4. STORMWATER MANAGEMENT CONTROLS
4.1 Written Analysis
The soils on this site are classified by the USGS Soil Survey as Altvan-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 geotechnical report indicates that the soils on site have a porosity as high
as 108 feet per day. 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 perimeter to control sediment transport
from rainfall and from wind. The silt fence that is located in the proposed pavement areas
will be removed prior to placing new pavement. Rock socks will be utilized in the
existing curb 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 and on the existing concrete sidewalks.
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.
5
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 4.5 for the timing of the construction phases and the sequential
installation of all BMP phasing for this site.
Refer to the end of Section 4.4 for the Erosion Control Surety calculations.
4.2 SWMP contact information
Permit holder:
Name:
Address:
Phone Number:
Email Address:
Appointed agent:
Name:
Address:
Phone Number:
Email Address:
6
4.3 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
4.4 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 demolition, 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
7
material, the sediment will be trapped and not transported downstream. Rock socks shall be
implemented in the existing curb line of Linden Street as shown on the Drainage & Erosion
Control Plan. Inlet Protection shall be located around the existing curb inlet in Linden. Once
construction of Willow is complete, rock socks will be placed in the curb line and inlet
protection will be placed around the existing inlet.
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 existing curb, refer to site map X
Earthen diversion dams
Vegetated swales
Sediment trap/pond
Pipe slope drains
Geogrid
Inlet/outlet protection Existing inlet, refer to site map X
Culverts
Riprap
Erosion control mats
Inlet protection At inlets, refer to site map 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
8
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.
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
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
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 16 $160.00
12 RRB LF $0.00
13 SB LF $0.00
14 SCL LF $0.00
15 SM AC $0.00
16 SF LF 625 $1,875.00
17 RS LF 35 $350.00
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
$5,085.00
$762.75
$5,847.75
$1,500.00
Maintenance & replacements (15%)
$3.00
$10.00
Construction Fence
Vehicle Tracking Control (2)
Topsoil (6-inch Lift)
Temporary Stream Crossing
Surface Roughening
Stabilized Staging Area
Reinforced Rock Berm
Sediment Basin
(1)
Rock Sock
Silt Fence
Construction Markers
Culvert Inlet Filter
Dewatering
Diversion Ditch (Unlined)
Diversion Ditch (ECM or plastic)
Sediment/Erosion Control Matting
Inlet Protection
Unit
FEEDERS SUPPLY REDEVELOPMENT
g
__________________________________________________________________________________________
Seeding and Mulching
Sediment Control Log (Wattle)
Item
No.
Check Dam (Reinforced)
Concrete Washout Area
Check Dam
$10.00
10
4.5 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. Because this is
an
Infill and redevelopment site, natural BMP’s will be difficult to implement.
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 storm drain inlet protection at existing inlets, install rock socks
in existing curb flowline, set dumpster.
Phase 2 – Demolition
Demo existing building section slated for demolition, remove debris from site. Demo
existing pavements and remove debris from site.
Phase 3 - Overlot Grading
Cut and fill on site to achieve subgrade elevations
Phase 4 - Utilities
Excavate and install for water and sewer, excavate and install dry utilities, install storm
and pipe for LID swales.
Phase 5 – Exterior concrete
Establish temporary concrete washout area, cut for curb and gutter and walks, place
concrete curbs and walks.
Phase 6 – Site Paving
Install sub base, install Asphalt pavement, install additional rock socks in new curb.
Phase 7 – Building construction
Install concrete foundation, remove concrete washout. Complete building construction
Phase 8 – Landscape installation
Backfill curbs and final shape planting areas, complete LID swale construction, Install
irrigation system, Landscape plant installation, Install mulch ground cover, remove silt
fence.
Phase 9 – Final Stabilization
11
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. Remove rock socks and inlet protection
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 Refer to site map X
Fuel storage located in bulk tanks
with secondary containment &
spill kit
Mobile fueling performed at least
200 feet away from drainages &
fully attended
Refer to site map X
Fertilizers, form oil, solvents,
cleaners, detergent stored in 55 gal
or smaller containers, kept in
storage units
Refer to site map X
Dumpsters containing used
chemicals containers & liquid
wastes kept covered
Refer to site map 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:
12
Vehicle tracking control pad shall be installed wherever construction vehicle access
routes intersect paved public roads. Vehicle tracking control pads shall be installed to
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 is shown on the site map. 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.
13
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:
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.
5. CONCLUSIONS
5.1. Compliance with Standards
All computations that have been completed within this report will be in compliance with
the City of Fort Collins Erosion Control Reference Manual for Construction Sites and the
City of Fort Collins Stormwater Criteria Manual.
5.2. Drainage Concept
The proposed drainage concepts presented in this report, in the final drainage report and
on the construction plans, will adequately provide for stormwater quality treatment for
the proposed improvements. Conveyance elements have been designed to convey
required flows to the proposed water quality swales and the existing regional detention
facility and ultimately to the Cache la Poudre River.
If, at the time of construction, groundwater is encountered, a Colorado Department of
Health Construction Dewatering Permit will be required.
14
6. REFERENCES
1. City of Fort Collins, “Storm Drainage Criteria Manual”, (SDCM), dated March
1999.
2. Urban Drainage and Flood Control District, “Urban Storm Drainage Criteria
Manual”, Volumes 1 and 2, dated June 2001, and Volume 3 dated September
2001.
A
APPENDIX A
VICINITY MAP
B
APPENDIX B
HYDROLOGIC COMPUTATIONS
North Star Design, Inc.
700 Automation Drive, Unit I
Windsor, CO 80550
LOCATION: Feeder Supply
PROJECT NO: 173-09
COMPUTATIONS BY: PPK
DATE: 10/7/2013
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
historic basin 1.14 49,853 5,233 0 1,760 18673 24,187 28% 0.21 0.29 0.37 0.56
Basin 1A 0.75 32,718 18,525 10,002 508 0 3,683 83% 0.63 0.66 0.69 0.77
Basin 1B 0.39 17,135 9,041 6,624 1,028 0 442 92% 0.75 0.77 0.79 0.85
Basin 1 Total 1.14 49,853 27,566 16,626 1,536 0 4,125 86% 0.67 0.69 0.72 0.79
RUNOFF COEFFICIENTS & % IMPERVIOUS
Flow.xls Cval
North Star Design, Inc.
700 Automation Drive, Unit I
Windsor, CO 80550
LOCATION: Feeder Supply
PROJECT NO: 173-09
COMPUTATIONS BY: PPK
DATE: 10/7/2013
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)
historic basin historic basin 1.14 0.29 35 0.010 8.7 305 0.005 D 10 0.7 7.2 15.9 340 11.9 11.9
Basin 1A Basin 1A 0.75 0.66 26 0.030 2.9 205 0.005 F 20 1.4 2.4 5.3 231 11.3 5.3
Basin 1B Basin 1B 0.39 0.77 26 0.030 2.2 205 0.005 F 20 1.4 2.4 4.6 231 11.3 5.0
Basin 1 Total Basin 1 Total 1.14 0.69 26 0.030 2.6 205 0.005 F 20 1.4 2.4 5.1 231 11.3 5.1
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.xls TOC5
North Star Design, Inc.
700 Automation Drive, Unit I
Windsor, CO 80550
LOCATION: Feeder Supply
PROJECT NO: 173-09
COMPUTATIONS BY: PPK
DATE: 10/7/2013
DIRECT RUNOFF TOTAL Inlet Capacity REMARKS
DESIGN SUBBASIN A C2 tc iQ2 Q2 Total
POINT ID
(ac) (min) (in/hr) (cfs) (cfs) (cfs)
historic basin historic basin 1.14 0.21 11.9 2.08 0.5 0.5
Basin 1A Basin 1A 0.75 0.63 5.3 2.84 1.3 1.3
Basin 1B Basin 1B 0.39 0.75 5.0 2.84 0.8 0.8
Basin 1 Total Basin 1 Total 1.14 0.67 5.1 2.84 2.2 2.2
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.xls Q2
North Star Design, Inc.
700 Automation Drive, Unit I
Windsor, CO 80550
LOCATION: Feeder Supply
PROJECT NO: 173-09
COMPUTATIONS BY: PPK
DATE: 10/7/2013
DIRECT RUNOFF TOTAL Inlet Capacity REMARKS
DESIGN SUBBASIN A C10 tc iQ10 Q10 Total
POINT ID
(ac) (min) (in/hr) (cfs) (cfs) (cfs)
historic basin historic basin 1.14 0.37 11.9 3.56 1.5 1.5
Basin 1A Basin 1A 0.75 0.69 5.3 4.85 2.5 2.5
Basin 1B Basin 1B 0.39 0.79 5.0 4.85 1.5 1.5
Basin 1 Total Basin 1 Total 1.14 0.72 5.1 4.85 4.0 4.0
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.xls Q10
North Star Design, Inc.
700 Automation Drive, Unit I
Windsor, CO 80550
LOCATION: Feeder Supply
PROJECT NO: 173-09
COMPUTATIONS BY: PPK
DATE: 10/7/2013
DIRECT RUNOFF TOTAL Inlet Capacity REMARKS
DESIGN SUBBASIN A C100 t
c iQ100
Q100 Total
POINT ID
(ac) (min) (in/hr) (cfs) (cfs) (cfs)
historic basin historic basin 1.14 0.56 11.9 7.26 4.7 4.7
Basin 1A Basin 1A 0.75 0.77 5.3 9.91 5.7 5.7 to LID swales
Basin 1B Basin 1B 0.39 0.85 5.0 9.91 3.3 3.3 to Inlet
Basin 1 Total Basin 1 Total 1.14 0.79 5.1 9.91 9.0 9.0
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.xls Q100
C
APPENDIX C
HYDRAULIC COMPUTATIONS
Project =
Inlet ID =
Design Information (Input) MINOR MAJOR
Type of Inlet Type =
Local Depression (additional to continuous gutter depression 'a' from 'Q-Allow') alocal
= 1.00 1.00 inches
Number of Unit Inlets (Grate or Curb Opening) No = 1 1
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
Area Opening Ratio for a Grate (typical values 0.15-0.90) Aratio
= 0.47 0.47
Clogging Factor for a Single Grate (typical value 0.50 - 0.70) Cf
(G) = 0.50 0.50
Grate Weir Coefficient (typical value 3.00) Cw
(G) = 3.00 3.00
Grate Orifice Coefficient (typical value 0.67) Co
(G) = 0.67 0.67
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
= 5.50 5.50 inches
Height of Curb Orifice Throat in Inches Hthroat
= 5.25 5.25 inches
Angle of Throat (see USDCM Figure ST-5) Theta = 0.0 0.0 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 2.30-3.00) Cw
(C) = 2.30 2.30
Curb Opening Orifice Coefficient (typical value 0.67) Co
(C) = 0.67 0.67
Resulting Gutter Flow Depth for Grate Inlet Capacity in a Sump MINOR MAJOR
Clogging Coefficient for Multiple Units Coef = 1.00 1.00
Clogging Factor for Multiple Units Clog = 0.50 0.50
Grate as a Weir: The Controlling Factor Will Be: Curb Opening as Weir Curb Opening As Vertical Orifice
Flow Depth at Local Depression without Clogging (1.5 cfs grate, 0 cfs curb) dwi
= 3.77 5.27 inches
Flow Depth (Curb Opening Only) without Clogging (0 cfs grate, 1.5 cfs curb) dcurb-un
= 2.56 4.34 inches
Flow Depth at Local Depression with Clogging (1.5 cfs grate, 0 cfs curb) dwa
= 5.05 7.41 inches
Flow Depth (Curb Opening Only) with Clogging (0 cfs grate, 1.5 cfs curb) dcurb-cl
= 2.65 5.70 inches
Grate as an Orifice MINOR MAJOR
Flow Depth at Local Depression without Clogging (1.5 cfs grate, 0 cfs curb) doi
= 1.47 2.48 inches
Flow Depth at Local Depression with Clogging (1.5 cfs grate, 0 cfs curb) doa
= 2.33 3.06 inches
Resulting Gutter Flow Depth Outside of Local Depression da-Grate = 1.65 4.70 inches
Resulting Gutter Flow Depth for Curb Opening Inlet Capacity in a Sump MINOR MAJOR
Clogging Coefficient for Multiple Units Coef = 1.00 1.00
Clogging Factor for Multiple Units Clog = 0.10 0.10
Curb as a Weir, Grate as an Orifice MINOR MAJOR
Flow Depth at Local Depression without Clogging (1.05 cfs grate, 0.45 cfs curb) dwi
= 1.16 1.96 inches
Project Description
Friction Method Manning Formula
Solve For Discharge
Input Data
Roughness Coefficient 0.010
Channel Slope 1.30 %
Normal Depth 11.50 in
Diameter 12 in
Results
Discharge 5.66 ft³/s
Flow Area 0.77 ft²
Wetted Perimeter 2.73 ft
Hydraulic Radius 3.40 in
Top Width 0.40 ft
Critical Depth 0.94 ft
Percent Full 95.8 %
Critical Slope 0.01292 ft/ft
Velocity 7.31 ft/s
Velocity Head 0.83 ft
Specific Energy 1.79 ft
Froude Number 0.93
Maximum Discharge 5.68 ft³/s
Discharge Full 5.28 ft³/s
Slope Full 0.01494 ft/ft
Flow Type SubCritical
GVF Input Data
Downstream Depth 0.00 in
Length 0.00 ft
Number Of Steps 0
GVF Output Data
Upstream Depth 0.00 in
Profile Description
Profile Headloss 0.00 ft
Average End Depth Over Rise 0.00 %
Normal Depth Over Rise 95.83 %
Downstream Velocity Infinity ft/s
Worksheet for Storm 1A
10/7/2013 3:05:43 PM
Bentley Systems, Inc. Haestad Methods Solution Center Bentley FlowMaster [08.11.00.03]
27 Siemons Company Drive Suite 200 W Watertown, CT 06795 USA +1-203-755-1666 Page 1 of 2
GVF Output Data
Upstream Velocity Infinity ft/s
Normal Depth 11.50 in
Critical Depth 0.94 ft
Channel Slope 1.30 %
Critical Slope 0.01292 ft/ft
Worksheet for Storm 1A
10/7/2013 3:05:43 PM
Bentley Systems, Inc. Haestad Methods Solution Center Bentley FlowMaster [08.11.00.03]
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 Normal Depth
Input Data
Roughness Coefficient 0.013
Channel Slope 2.00 %
Diameter 12 in
Discharge 3.30 ft³/s
Results
Normal Depth 7.08 in
Flow Area 0.48 ft²
Wetted Perimeter 1.75 ft
Hydraulic Radius 3.30 in
Top Width 0.98 ft
Critical Depth 0.78 ft
Percent Full 59.0 %
Critical Slope 0.00952 ft/ft
Velocity 6.84 ft/s
Velocity Head 0.73 ft
Specific Energy 1.32 ft
Froude Number 1.72
Maximum Discharge 5.42 ft³/s
Discharge Full 5.04 ft³/s
Slope Full 0.00858 ft/ft
Flow Type SuperCritical
GVF Input Data
Downstream Depth 0.00 in
Length 0.00 ft
Number Of Steps 0
GVF Output Data
Upstream Depth 0.00 in
Profile Description
Profile Headloss 0.00 ft
Average End Depth Over Rise 0.00 %
Normal Depth Over Rise 59.02 %
Downstream Velocity Infinity ft/s
Worksheet for Storm 1B
10/7/2013 3:07:58 PM
Bentley Systems, Inc. Haestad Methods Solution Center Bentley FlowMaster [08.11.00.03]
27 Siemons Company Drive Suite 200 W Watertown, CT 06795 USA +1-203-755-1666 Page 1 of 2
GVF Output Data
Upstream Velocity Infinity ft/s
Normal Depth 7.08 in
Critical Depth 0.78 ft
Channel Slope 2.00 %
Critical Slope 0.00952 ft/ft
Worksheet for Storm 1B
10/7/2013 3:07:58 PM
Bentley Systems, Inc. Haestad Methods Solution Center Bentley FlowMaster [08.11.00.03]
27 Siemons Company Drive Suite 200 W Watertown, CT 06795 USA +1-203-755-1666 Page 2 of 2
Flow Depth at Local Depression with Clogging (0.85 cfs grate, 0.65 cfs curb) dwa
= 1.60 2.69 inches
Curb as an Orifice, Grate as an Orifice MINOR MAJOR
Flow Depth at Local Depression without Clogging (1.5 cfs grate, 0 cfs curb) doi
= 1.47 2.48 inches
Flow Depth at Local Depression with Clogging (1.5 cfs grate, 0 cfs curb) doa
= 2.33 3.06 inches
Resulting Gutter Flow Depth Outside of Local Depression da-Curb = 1.33 2.06 inches
Resultant Street Conditions MINOR MAJOR
Total Inlet Length L = 3.0 3.0 feet
Total Inlet Interception Capacity (Design Discharge from Q-Peak ) Qa = 1.5 3.3 cfs
Resultant Gutter Flow Depth (based on sheet Q-Allow geometry) d = 1.65 4.24 inches
Resultant Street Flow Spread (based on sheet Q-Allow geometry) T = 1.3 9.3 feet
Resultant Flow Depth at Street Crown dCROWN = 0.00 0.00 inches
CDOT/Denver 13 Combination
INLET IN A SUMP OR SAG LOCATION
Feeders Supply
Inlet 1
H-Vert
H-Curb
W
Lo (C)
Lo (G)
Wo
W
P
Inlet 1.xls, Inlet In Sump 10/7/2013, 2:47 PM
$1,200.00
SEDIMENT/EROSION CONTROL
BEST MANAGEMENT PRACTICES (BMPs)
COST OPINION SPREADSHEET
BMP ID
Installation
Unit Cost
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Erosion control escrow amount
Subtotal