HomeMy WebLinkAbout14 - Design Report - Cattail Properties - Stormwater 1
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Storm Water Management Design Report
Cattail Townhomes
Corner of Cattail Street and Black Bird Dr.
Bozeman, Montana
October 2014
Prepared By:
Genesis Engineering, Inc.
GEI Project#: 1097.001.040
Prepared For:
Taylor Properties
Bozeman, Montana
204 N. 1 P Ave.,Bozeman,MT 59715 Cell:(406)581-3319 www.q-e-i.net Page 1 of 8
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ENGINEERING,INC
Storm Water Management Design Report
Table of Contents
I. Project Background.............................................................................................................. 4
1. Introduction............................................................................................................................... 4
2. Soil and Groundwater.............................................................................................................. 4
3. Land Use..................................................................................................................................... 4
II. Existing Conditions.................................................................................................................. 4
1. Drainage Basins and Pre-Development Peak Flows............................................................ 4
III. Proposed Drainage Plan and Post-Development Peak Flows........................................ 5
1. Major Drainage System........................................................................................................... 6
2. Minor Drainage System........................................................................................................... 6
3. Maintenance............................................................................................................................. 7
IV. Conclusion................................................................................................................................ 7
List of Tables
Table 1. Estimated Pre-Development Peak Flows................................................................................... 5
Table 2. Estimated Capacity of Existing Drainage Facilities................................................................... 5
Table 3. Estimated Post-Development Peak Flows................................................................................. 5
Table4. Required Pond Volumes.............................................................................................................. 6
Table 5. Proposed Drainage Facility Capacity.......................................................................................... 6
Appendix A—Calculations
Grading and Drainage Exhibits
Pre/Post Development Runoff Computations
Storm Pond Computations
Street&Alley Gutter Flow Modeling
List of References
City of Bozeman Design Standards and Specifications Policy, March 2004,and all addenda.
204 N. 11t'Ave.,Bozeman,MT 59715 Cell:(406)581-3319 www.g-e-i.net ' Page 2 of 8
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I. Project Background
Introduction
The Cattail Townhomes Project consists of 50 proposed townhome units on two existing lots(Lots 3&4)
within the existing Cattail Creek Subdivision. These existing lots are shaded in green in Figure 1 below and
consist of approximately 5.21 acres,more specifically located at the corner of Cattail Street and Blackbird Drive
in Bozeman,Gallatin County, Montana.
This report outlines the storm water analysis conducted for the site and describes the storm water drainage
and management facilities necessary for the Cattail Townhomes by state and local regulations. We also
explore the capacity of the existing stormwater facilities already provided for and how runoff from the
proposed project fits into this existing infrastructure. The storm water plan follows the design standards set
forth by the City of Bozeman in Design Standards and Specifications Policy,March 2004 and three subsequent
addenda.
Soil and Groundwater
The NRCS Soil Survey identifies the major soil types on the site as Enbar and Meadow Creek Loams(509B&
510B). These soils belong to hydrologic soil group B as they are comprised primarily of loams and silt loams
with moderately high saturated hydraulic conductivity.
Land Use
The existing land use is high density multifamily with up to 87 units from the original Cattail Creek Subdivision
Phases 2A and 2B in 2003. However,the currently proposed use is for only 50 townhome units.
_ u J Ir�wV'• PUT OF CATTAIL CREEK SUBONISION PHASES 2A&YB
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NGINEERING,INC
Figure 1—Lots 3 and 4 and existing storm pond within the
existing Cattail Creek Plat.
II. Existing Conditions
The Cattail Townhome Project lies south of Cattail Street + /
with Blackbird Drive on the east boundary.The existing land
slopes generally to the northeast at a grade of j d rr
approximately 1.6%. The high point of the property is I
located on the south west corner of the property. These '" 5
natural topographic features convey the pre-development
runoff overland into the Cattail Steet and Balckbird Drive '
curb and gutter systems. The runoff then flows to the east f
along Cattail Street where it is intercepted by two sets of r
double"H"storm drain inlets and fed into the existing 8,900 }. N
CFT detention pond just north of Cattail Street. This e 3,
description of the stormwater path is consistent with the `r `--
storm water masterplan as defined during the Cattail CreekSubarea
Subdivision process and as-built plan sheets can be found int�`�•-
the appendix. A post development plan for these two lots
was already accounted for in the original Plat submittal and
design report complete by TD&H in 2002. E
Genesis will verify if that the existing stormwater facilities ,
provide the stormwater management required for the most
recent proposed development of the subject lots. V '�
Figure 2— e $
Offsite basin A&Regional basin C b'
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Figure 3—Project specific basins B-1 through B-4 and Regional Pond in NE corner.
204 N. 11`"Ave.,Bozeman,MT 59715 Cell:(406)581-3319 www.q-e-i.net Page 4 of 8
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Drainage Basins and Pre-development Peak Flows
As part of our analysis,Genesis identified the existing offsite drainage basin and the onsite drainage basin onsite as
shown on drawings GD1 in Appendix A. The 28 acre off-site basin stretches from the south boundary of the subject lots
to the south,approximately 2300 feet ending at Baxter Lane. Estimates of runoff and their respective calculations for
the existing and subareas were completed using the Modified Rational Method. Our large basin model uses a pre-
development runoff coefficient of 0.55 which represents developed ground cover resulting in more conservative
calculations of peak flow bypassing around the subject lots. We will also use a pre-development C=0.20 for our onsite
drainage basins when calculating pre-development flow rates and detention pond volumes.
Genesis looked at many storm events such as the 10-year,25-year and 100-yr in the analysis of the existing storm water
conveyance facilities within the site. A summary of estimated pre-development peak runoff rates as well as existing
drainage facility capacities can be found in Tables 1 and 2. Detailed calculations are available in Appendix A.
Table 1. Estimated Pre-Development Peak Flows
Sub Area Description Area Tc Q10 Q25 Q100
(acres) (min) (cfs) (cfs) (cfs)
A Offsite Basin 28 70 3.6 4.7 5.7
B-1 Project Specific Basin 1.0 10 0.4 0.5 0.7
B-2 Project Specific Basin 3.1 10 1.3 1.5 2.1
B-3 Project Specific Basin 1.9 10 0.8 0.9 1.2
B-4 Project Specific Basin 0.4 10 0.2 0.2 0.3
c Regional Pond Basin 12.17 20 2.8 3.3 4.4
III. Proposed Drainage Plan and Estimated Post-Development Peak Flows
The proposed drainage plan shall utilize the existing drainage systems that are currently in place. Genesis'drainage
plan consists of two drainage systems. First,the major drainage system or backbone usually consists of natural
streams,site grading,and street conveyance. These facilities are designed to have a much higher conveyance capacity
and shall convey the excess runoff from the 100-year storm without inundating any building structures. Secondly,the
minor drainage system(s)fit within the major drainage system and are designed to accommodate moderate and
relatively frequent storm events without inconveniencing the public. The minor drainage system is comprised of the
curb and gutters,inlets,piping,and shallow swales designed to convey runoff from the 25-year event,and retention or
detention ponds designed for the 10-year storm event. Table 2 presents a summary of expected post-development
peak flow rates passing through the proposed project.
Table 2. Estimated Post-Development Peak Flows
Sub Area Description Area Tc Q10 Q25 Q300
(acres) (min) (cfs) (cfs) (cfs)
A Offsite Basin 28 60 9.9 11.7 15.6
B-1 Project Specific Basin 1.0 10 1.3 1.5 2.0
B-2 Project Specific Basin 3.1 10 4.0 4.6 6.3
B-3 Project Specific Basin 1.9 10 2.4 2.8 3.8
B-4 Project Specific Basin 0.4 10 0.6 0.6 0.9
c Regional Pond Basin 12.17 25 9.8 11.7 15.7
9 204 N. 11"Ave., Bozeman,MT 59715 Cell:(406)581-3319 www.q-e-i.net i*� Page 5 of 8
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Major Drainage System
The project's major drainage system is comprised of a natural Swale on the south boundary of Lots 3 and 4,the two
public streets and alleys,and the existing stream on the east boundary of the park area. Additional grading onsite shall
be completed as necessary so that runoff resulting from storm events between the 25-year and 100-year will be
conveyed down the Swale,streets,and alleys without inundating any structures or causing significant erosion. Table 3
has the results of Manning Equation flow calculations for open channel flow in swales and streets.
Table 3. Drainage Structure Capacities
Structure Type of Contributing Depth Slope Q25post Q100post QCap Passes
Flow Subareas (ft) W (cfs) (cfs) (cfs) Design Storm
South Swale Channel A 1.0 0.5 11.7 15.6 18 y
Street A Street B-3 0.5 0.6 2.8 3.8 28 y
Alley A&B Street B-2 0.3 1.0 6.3 6.3 10 y
Cattail Street A+C 0.5 1.2 13.4 18 66 y
Existing HH Inlets Inlets A+C 0.5 1.2 13.4 18 15 y
All existing and proposed drainage structures are adequately sized to convey the large event post-development runoff
that is generated by the Cattail Townhome Subdivision and
contributing adjacent areas.
Regional Pond
Minor Drainage System (Subarea C) \
The proposed minor drainage system includes inverted alleys
and city streets with curb and gutter to direct runoff into the
existing detention pond. The existing detention pond is
located at the north side of Cattail Drive and will attenuate I
runoff generated by the existing and new site development
(Subarea C).The design storm event is the 10-year event with
discharge from the detention pond limited to the 10-year pre- P �, 1:. '
development peak flow rate as designed by TD&H. The City of
Bozeman Design Standards and Specifications Policy requires
that detention pond volume be adequate to accommodate the
oa
difference in peak runoff between the pre-development and �\4e
post-development design storm of 10 years,while retention
ponds must contain the entire 10-year 2-hour design storm
volume. All pond side slopes have been sloped to finished
grade at 4H:1V. \
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Figures 4&5—Existing Pond "C"off of
° > Cattail Drive from TD&H as-builts.
1-3319 www.q-a-i.net Page 6 of 8
CGIVE
GINEERING,INC
The existing detention pond can be seen in Figures 4&5 above. It has an outlet structure comprised of an arch culvert
sized and sloped to only convey only the 10-year pre-development flow rate from the design basin. Larger storm
events will overtop the weir and safely flow down into the existing drainage way. Genesis used the modified rational
method with a basin size of 12.17 acres,a time of concentration of 20 minutes,and a weighted runoff coefficient of C=
0.61. Since the proposed Townhome lots are the last contributing area to develop,we believe the estimate of the
weighted runoff coefficient for the entire design basin is very representative of the actual ground cover. Table 4 shows
the calculated pond volume compared to the measured pond volume.
Table 4. Existing Pond Volumes
Pond Type Location Contributing Q10Pre Q10Post Q25Post Volume
Subarea (cfs) (cfs) (cfs) (cft)
Existing"C" Detention Regional C 2.8 9.8 11.8 8,500
Existing"C" As meas.in the field C 2.8 9.8 11.8 9,200
Therefore the existing detention pond has the available capacity to receive runoff from the proposed Cattail Townhome
project as described and still provide the required attenuation before releasing.
Maintenance
Regular maintenance of storm water facilities is necessary for proper functioning of the drainage system. In general,
regular mowing of any grass swales and storage ponds and unclogging of inlets and outlet works will be required to
prevent standing water,clogging,and the growth of weeds and wetland plants. More substantial maintenance,such as
sediment removal with heavy equipment, may be required in coming decades to restore detention pond volume.
All maintenance and repair should be prioritized and scheduled in advance. Inlets&pipes should be visually inspected
yearly. Typical maintenance items include removing obstructions,cleaning and flushing pipes, mowing grass and
weeds,tree maintenance to prevent limbs from falling and blocking swales,and establishing groundcover on bare
ground.
IV. Conclusion
Our Storm water analysis and calculations indicate that the existing storm water facilities and management plan for the
subdivision including the proposed project is adequate to safely convey the 10-year,25-year,and 100-year storm
events and to satisfy state and local regulations for 10-year peak attenuation utilizing the existing detention pond north
of Cattail Drive.
H:\1097\001\DOCS\Design\Storm\StormwaterDR.doc
204 N. 11`h Ave.,Bozeman,MT 59715 Cell:(406)581-3319 www.o-e-i.net R Page 7 of 8
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Appendix A
Calculations
204 N. 11"Ave.,Bozeman,MT 59715 Cell:(406)581-3319 www.q-e-i.net Page 8 of 8
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FIGURE?-1 TIME CF CONCEN'IRA ION nalFormula",
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GE111: 1097.001
DATE: 10/24/2014
ENGINEER: JRM
Subarea A-10YR
MODIFIED RATIONAL METHOD
Qp=CiA
PRE-DEVELOPMENT
RAINFALL FREQ= 10 YR(DURATION=1) i=A*(Tc/60) ° (CITY OF BOZEMAN)
BASIN AREA PRE= 28 AC STORM EVENT STORM i COEFF INTENSITY
IYR _ A B IN HR
PRE-DEV Tc= 60.0 MIN 2 0.36 0.6 0.36
5 0.52 0.64 0.52
PRE-DEV C= 0.20 10 0.64 0.66 0.64
25 0.78 0.64 0.78
STORM A= 0.64 50 0.92 0.66 0.92
B= 0.66 100 1.01 0.67 1.01
STORM INTENSITY= 0.64 IN/HR
PRE-DEV Qp= 3.58 CFS
POST-DEVELOPMENT
BASIN AREA POST= 28.00 AC
POST-DEV Tc= 60.0 MIN
POST-DEV C= 0.55
STORM INTENSITY= 0.64 IN/HR
POST-DEV Qp= 9.86 CFS
H:\1097\001\DOGS\Design\Storm\Sub A-10YR.xls 1 OF 1 PRINTED: 11/5/2014
GEI#: 1097.001
DATE: 10/24/2014
ENGINEER: 1RM
Subarea A-25YR
MODIFIED RATIONAL METHOD
Qp=CiA
PRE-DEVELOPMENT
RAINFALL FREQ= 25 YR(DURATION=1) i=A*(Tc/60)_e (CITY OF BOZEMAN)
BASIN AREA PRE= 28 AC STORM EVENT STORM i COEFF INTENSITY
YR A B IN/HR
PRE-DEV Tc= 60.0 MIN --Z____..__._ .._.....___
0.36 0.6 0.36
5 0.52 0.64 0.52
PRE-DEV C= 0.20 10 0.64 0.66 0.64
25 0.78 0.64 0.78
STORM A= 0.78 50 0.92 0.66 0.92
B= 0.64 1 100 1.01 0.67 1.01
STORM INTENSITY= 0.78 IN/HR
PRE-DEV Qp= 4.37 CFS
POST-DEVELOPMENT
BASIN AREA POST= 28.00 AC
POST-DEV Tc= 60.0 MIN
POST-DEV C= 0.55
STORM INTENSITY= 0.78 IN/HR
POST-DEV Qp= 12.01 CFS
HAl 097\001\DOCS\Design\Storm\Sub A-25YR.xls 1 OF 1 PRINTED 11/5/2014
GEW 1097.001
DATE: 10/24/2014
ENGINEER: 1RM
Subarea A -100YR
MODIFIED RATIONAL METHOD
Qp=CiA
PRE-DEVELOPMENT
RAINFALL FREQ= 100 YR(DURATION=1) i=A*(Tc/60).e (CITY OF BOZEMAN)
BASIN AREA PRE= 28 AC STORM EVENT STORM i COEFF INTENSITY
YR _ A_ B IN/HR
PRE-DEV Tc= 60.0 MIN 2 0.36� 0.6 0.36
S 0.52 0.64 0.52
PRE-DEV C= 0.20 10 0.64 0.66 0.64
25 0.78 0.64 0.78
STORM A= 1.01 50 0.92 0.66 0.92
B= 0.67 100 1.01 0.67 1.01
STORM INTENSITY= 1.01 IN/HR
PRE-DEV Qp= 5.66 CFS
POST-DEVELOPMENT
BASIN AREA POST= 28.00 AC
POST-DEV Tc= 60.0 MIN
POST-DEV C= 0.55
STORM INTENSITY= 1.01 IN/IiR
POST-DEV Qp= 15.55 CFS
H:\1097\001\DOGS\Design\Storm\Sub A-100YR.xls 1 OF'I PRINTED: 11/5/2014
GEI#: 1097.001
DATE: 10/24/2014
ENGINEER: JRM
Subarea B-1 -10YR
MODIFIED RATIONAL METHOD
Qp=CiA
PRE-DEVELOPMENT
RAINFALL FREQ= 10 YR(DURATION=1) i=A"(Tc/60)'6 (CITY OF BOZEMAN)
BASIN AREA PRE= 0.99 AC STORM EVENT STORM i COEFF INTENSITY
YR_ _ A B INMR
PRE-DEV Tc= 10.0 MIN 2 0.36 0.6 1..0.5
5 0.52 0.64 1.64
PRE-DEV C= 0.20 10 0.64 0.66 2.09
25 0.78 0.64 2.46
STORM A= 0.64 50 0.92 0.66 3.00
B= 0.66 100 1.01 0.67 3.35
STORM INTENSITY= 2.09 IN/HR
PRE-DEV Qp= 0.41 CFS
POST-DEVELOPMENT
BASIN AREA POST= 0.99 AC
POST-DEV Tc= 10.0 MIN
POST-DEV C= 0.61
STORM INTENSITY= 2.09 IN/FIR
POST-DEV Qp= 1.26 CFS
H:\1097\001\DOCS\Design\Storm\Sub B-1-10YR.xls 1 OF 1 PRINTED: 11/5/2014
GEI#: 1097.001
DATE: 10/24/2014
ENGINEER: 1RM
Subarea B-1 -25YR
MODIFIED RATIONAL METHOD
Qp=CiA
PRE-DEVELOPMENT
RAINFALL FREQ= 25 YR(DURATION=1) i=A"(Tc/60).g (CITY OF BOZEMAN)
BASIN AREA PRE= 0.99 AC STORM EVENT STORM i COEFF INTENSITY
YR A B IN/HR
PRE-DEVTc= 10.0 MIN 2 0.36 0.6 1.05
5 0.52 0.64 1.64
PRE-DEV C= 0.20 10 0.64 0.66 2.09
25 0.78 0.64 2.46
STORM A= 0.78 50 0.92 0.66 3.00
B= 0.64 100 1.01 0.67 3.35
STORM INTENSITY= 2.46 IN/HR
PRE-DEV Qp= 0.49 CFS
POST-DEVELOPMENT
BASIN AREA POST= 0.99 AC
POST-DEV Tc= 10.0 MIN
POST-DEV C= 0.61
STORM INTENSITY= 2.46 IN/HR
POST-DEV Qp= 1.48 CFS
H:\1097\001\DOGS\Design\Storm\Sub B-1-25YR.xls 1 OF 1 PRINTED: 11/5/2014
GEI##: 1097.001
DATE: 10/24/2014
ENGINEER: 1RM
Subarea B-1 -100YR
MODIFIED RATIONAL METHOD
Qp=CiA
PRE-DEVELOPMENT
RAINFALL FREQ= 100 YR(DURATION=1) i=A*(Tc/60) (CITY OF BOZEMAN)
BASIN AREA PRE= 0.99 AC STORM EVENT STORM i COEFF INTENSITY
YR) A B IN/HR
PRE-DEV Tc= 10.0 MIN 2 0.36 0.6 1..05
5 0.52 0.64 1.64
PRE-DEV C= 0.20 10 0.64 0.66 2.09
25 0.78 0.64 2.46
STORM A= 1.01 50 0.92 0.66 3.00
B= 0.67 1 100 1.01 0.67 3.35
STORM INTENSITY= 3.35 IN/HR
PRE-DEV Qp= 0.66 CFS
POST-DEVELOPMENT
BASIN AREA POST= 0.99 AC
POST-DEV Tc= 10.0 MIN
POST-DEV C= 0.61
STORM INTENSITY= 3.35 IN/HR
POST-DEV Qp= 2.03 CFS
H:\1097\001\DOGS\Design\Storm\Sub B-1-100YR.xis 1 OF 1 PRINTED: 11/5/2014
GEI#: 1097.001
DATE: 10/24/2014
ENGINEER: 1RM
Subarea B-2 -10YR
MODIFIED RATIONAL METHOD
Qp=CIA
PRE-DEVELOPMENT
RAINFALL FREQ= 10 YR(DURATION=1) i=A*(Tc/60) (CITY OF BOZEMAN)
BASIN AREA PRE= 3.1 AC STORM EVENT STORM i COEFF INTENSITY
(YR) A B IN/HR
PRE-DEVTc= 10.0 MIN 2 0.36 0.6 1.05
5 0.52 0.64 1.64
PRE-DEV C= 0.20 10 0.64 0.66 2.09
25 0.78 0.64 2.46
STORM A= 0.64 50 0.92 0.66 3.00
B= 0.66 100 1.01 0.67 3.35
STORM INTENSITY= 2.09 IN/HR
PRE-DEV Qp= 1.29 CFS
POST-DEVELOPMENT
BASIN AREA POST= 3.10 AC
POST-DEV Tc= 10.0 MIN
POST-DEV C= 0.61
STORM INTENSITY= 2.09 IN/IiR
POST-DEV Qp= 3.95 CFS
H:\1097\001\DOGS\Design\Storm\Sub B-2-10YR.xls 1 OF 1 PRINTED: 11/.5/2014
GEIM 1097.001
DATE: 10/24/2014
ENGINEER: JRM
Subarea B-2 -25YR
MODIFIED RATIONAL METHOD
Qp=CiA
PRE-DEVELOPMENT
RAINFALL FREQ= 25 YR(DURATION=1) i=A*(Tc/60)'° (CITY OF BOZEMAN)
BASIN AREA PRE= 3.1 AC STORM EVENT STORM i COEFF INTENSITY
(YR) A B (IN/HR
PRE-DEVTc= 1.0.0 ' MIN 2 0.36 0.6 1.05
5 0.52 0.64 1.64
PRE-DEV C= 0.20 10 0.64 0.66 2.09
25 0.78 0.64 2.46
STORM A= 0.78 50 0.92 0.66 3.00
B= 0.64 100 1.01 0.67 3.35
STORM INTENSITY= 2.46 IN/HR
PRE-DEV Qp= 1.52 CFS
POST-DEVELOPMENT
BASIN AREA POST= 3.10 AC
POST-DEV Tc= 10.0 MIN
POST-DEV C= 0.61
STORM INTENSITY= 2.46 IN/HR
POST-DEV Qp= 4.64 CFS
H:\1097\001\DOCS\Design\Storm\Sub B-2-25YR.xis 1 OF 1 PRINTED: 11/5/2014
GEW 1097.001
DATE: 10/24/2014
ENGINEER: JRM
Subarea B-2 -100YR
MODIFIED RATIONAL METHOD
Qp=CiA
PRE-DEVELOPMENT
RAINFALL FREQ= 100 YR(DURATION=1) i=A*(Tc/60).e (CITY OF BOZEMAN)
BASIN AREA PRE= 3.1 AC STORM EVENT STORM i COEFF INTENSITY
(YR _ A B IN/HR
PRE-DEV Tc= 10.0 MIN 2 0.36 0.6 1.05
5 0.52 0.64 1.64
PRE-DEV C= 0.20 10 0.64 0.66 2.09
25 0.78 0.64 2.46
STORM A= 1.01 50 0.92 0.66 3.00
B= 0.67 100 1.01 0.67 3.35
STORM INTENSITY= 3.35 IN/HR
PRE-DEV Qp= 2.08 CFS
POST-DEVELOPMENT
BASIN AREA POST= 3.10 AC
POST-DEV Tc= 10.0 MIN
POST-DEV C= 0.61
STORM INTENSITY= 3.35 IN/HR
POST-DEV Qp= 6.34 CFS
H:\1097\001\DOCS\Design\Storm\Sub B-2-100YR.xls 1 OF 1 PRINTED: 1 1/512 0 1 4
GEI#: 1097.001
DATE: 10/24/2014
ENGINEER: JRM
Subarea R-3 -10YR
MODIFIED RATIONAL METHOD
Qp=CiA
PRE-DEVELOPMENT
RAINFALL FREQ= 10 YR(DURATION=1) i=A`(Tc/60)-e (CITY OF BOZEMAN)
BASIN AREA PRE= 1.85 AC STORM EVENT STORM i COEFF INTENSITY
(YR) A B IN/HR
PRE-DF..V Tc= 10.0 MIN 2 0.36 0.6 1.05
S 0.S2 0.64 1.64
PRE-DEV C= 0.20 10 0.64 0.66 2.09
25 0.78 0.64 2.46
STORM A= 0.64 SO 0.92 0.66 3.00
B= 0.66 100 1.01 0.67 3.35
STORM INTENSITY= 2.09 IN/HR
PRE-DEV Qp= 0.77 CFS
POST-DEVELOPMENT
BASIN AREA POST= 1.85 AC
POST-DEV Tc= 10.0 MIN
POST-DEV C= 0.61
STORM INTENSITY= 2.09 IN/HR
POST•DEV Qp= 2.36 CFS
H:\1097\001\DOGS\Design\Stone\Sub B-3-10YR.xls 1 OF 1 PRINTED: 11/5/2014
GEM 1097.001
DATE: 10/24/2014
ENGINEER: JRM
Subarea B-3 -2SYR
MODIFIED RATIONAL METHOD
Qp=CiA
PRE-DEVELOPMENT
RAINFALL FREQ= 25 YR(DURATION=1) i=A*(Tc/60)_e (CITY OF BOZEMAN)
BASIN AREA PRE= 1.85 AC STORM EVENT STORM i COEFF INTENSITY
(YR) A B IN/HR
PRE-DEV Tc= 10.0 MIN 2 0.36 0.6 1.05
5 0.52 0.64 1.64
PRE-DEV C= 0.20 10 0.64 0.66 2.09
25 0.78 0.64 2.46
STORM A= 0.78 50 0.92 0.66 3.00
B= 0.64 100 1.01 0.67 3.35
STORM INTENSITY= 2.46 IN/HR
PRE-DEV Qp= 0.91 CFS
POST-DEVELOPMENT
BASIN AREA POST= 1.85 AC
POST-DEV Tc= 10.0 MIN
POST-DEV C= 0.61
STORM INTEN5ITY= 2.46 IN/HR
POST-DEV Qp= 2.77 CFS
H:\1097\001\DOCS\Design\Storm\Sub B-3-25YR.xls 1 OF 1 PRINTED: 11/5/2014
GEI#: 1097.001
DATE: 10/24/2014
ENGINEER: JRM
Subarea B-3 -100YR
MODIFIED RATIONAL METHOD
Qp=CiA
PRE-DEVELOPMENT
RAINFALL FREQ= 100 YR(DURATION=1) i=A*(Tc/60)"6 (CITY OF BOZEMAN)
BASIN AREA PRE= 1.85 AC STORM EVENT STORM i COEFF INTENSITY
YR A B IN/HR
PRE-DEV Tc= 10.0 MIN 2 0.36 0.6 1..05
5 0.52 0.64 1.64
PRE-DEV C= 0.20 10 0.64 0.66 2.09
25 0.78 0.64 2.46
STORM A= 1.01 50 0.92 0.66 3.00
B= 0.67 100 1.01 0.67 3.35
STORM INTENSITY= 3.35 IN/HR
PRE-DEV Qp= 1.24 CFS
POST-DEVELOPMENT
BASIN AREA POST= 1.85 AC
POST-DEV Tc= 10.0 MIN
POST-DEV C= 0.61
STORM INTENSITY= 3.35 IN/HR
POST-DEV Qp= 3.79 CFS
H:\1097\001\DOCS\Design\Storm\Sub B-3-100YR.xls 1 OF 1 PRINTED: 11/5/2014
GEI#: 1097.001
DATE: 10/24/2014
ENGINEER: 1RM
Subarea B-4 -10YR
MODIFIED RATIONAL METHOD
Qp=CiA
PRE-DEVELOPMENT
RAINFALL FREQ= 10 YR(DURATION=1) i=A"(Tc/60).e (CITY OF BOZENIAN)
BASIN AREA PRE= 0.43 AC STORM EVENT STORM i COEFF INTENSITY
iYR A B IN/HR
PRE-DEV Tc= 10.0 MIN 2 0.36 0.6 1..05
5 0.52 0.64 1.64
PRE-DEV C= 0.20 10 0.64 0.66 2.09
25 0.78 0.64 2.46
STORM A= 0.64 50 0.92 0.66 3.00
B= 0.66 100 1.01 0.67 3.35
STORM INTENSITY= 2.09 IN/HR
PRE-DEV Qp= 0.18 CFS
POST-DEVELOPMENT
BASIN AREA POST= 0.43 AC
POST-DEV Tc= 10.0 MIN
POST-DEV C= 0.61
STORM INTENSITY= 2.09 IN/HR
POST-DEV Qp= 0.55 CFS
HA1097\001\DOCS\Design\Storm\Sub B-4-10YR.xls 1 OF 1 PRINTED: 11/5/2014
GEI#: 1097.001
DATE: 10/24/2014
ENGINEER: JRM
Subarea R-4 -25YR
MODIFIED RATIONAL METHOD
Qp=CiA
PRE-DEVELOPMENT
RAINFALL FREQ= 2.5 YR(DURATION=1) i=A"(Tc/60)_e (CITY OF BOZEMAN)
BASIN AREA PRE= 0.43 AC STORM EVENT STORM i COEFF INTENSITY
YR) _A _ B IN/HR
PRE-DEVTc= 10.0 MIN 2 �0.36 0.6 1.05
5 0.52 0.64 1.64
PRE-DEV C= 0.20 10 0.64 0.66 2.09
25 0.78 0.64 2.46
STORM A= 0.78 50 0.92 0.66 3.00
B= 0.64 100 1.01 0.67 3.35
STORM INTENSITY= 2.46 IN/HR
PRE-DEV Qp= 0.21 CFS
POST-DEVELOPMENT
BASIN AREA POST= 0.43 AC
POST-DEV Tc= 10.0 MIN
POST-DEV C= 0.61
STORM INTENSITY= 2.46 IN/I1R
POST-DEV Qp= 0.64 CFS
H:\1097\001\DOCS\Design\Storm\Sub B-4-25YR.xls 1 OF 1 PRINTED: 11/5/2014
GEW: 1097.001
DATE: 10/24/2014
ENGINEER: JRM
Subarea B-4-100YR
MODIFIED RATIONAL METHOD
Qp=CiA
PRE-DEVELOPMENT
RAINFALL FREQ= 100 YR(DURATION=1) i=A"(Tc/60) ° (CITY OF BOZEMAN)
BASIN AREA PRE= 0.43 AC STORM EVENT STORM i COEFF INTENSITY
YR _A B IN/HR
PRE-DEVTc= 10.0 MIN 2 0.36 0.6 1.05
5 0.52 0.64 1.64
PRE-DEV C= 0.20 10 0.64 0.66 2.09
25 0.78 0.64 2.46
STORM A= 1.01 50 0.92 0.66 3.00
B= 0.67 100 1.01 0.67 3.35
STORM INTENSITY= 3.35 IN/HR
PRE-DEV Qp= 0.29 CFS
POST-DEVELOPMENT
BASIN AREA POST= 0.43 AC
POST-DEV Tc= 10.0 MIN
POST-DEV C= 0.61
STORM INTENSITY= 3.35 IN/IAR
POST-DEV Qp= 0.88 CFS
H:\1097\001\DOCS\Design\Storm\Sub B-4-100YR.xis 1 OF 1 PRINTED: 11/5/2014
GEIN: 1097.001
DATE: 10/24/2014
ENGINEER: 1RM
Subarea C-10YR
MODIFIED RATIONAL METHOD
Qp=CIA
PRE-DEVELOPMENT
RAINFALL FREQ= 10 YR(DURATION=1) i=A*(Tc/60) ° (CITY OF BOZEMAN)
BASIN AREA PRE= 12.17 AC STORM EVENT STORM i COEFF INTENSITY
YR A B IN/HR
PRE-DEVTc= 25.0 MIN 2 0.36 0.6 0.61
5 0.52 0.64 0.91
PRE-DEV C= 0.20 10 0.64 0.66 1.14
25 0.78 0.64 1.37
STORM A= 0.64 50 0.92 0.66 1.64
B= 0.66 100 1.01 0.67 1.82
STORM INTENSITY= 1.14 IN/HR
PRE-DEV Qp= 2.78 CPS
POST-DEVELOPMENT
BASIN AREA POST= 12.17 AC
POST-DEV Tc= 20.0 MIN
POST-DEV C= 0.61
STORM INTENSITY= 1.32 IN/HR
POST-DEV Qp= 9.81 CPS
H:\1097\001\DOCS\Design\Storm\Sub C-10YR.xls 1 OF 1 PRINTED: 1 1/512 0 1 4
GEM 1097.001
DATE: 10/24/2014
ENGINEER: 1RM
Subarea C-25YR
MODIFIED RATIONAL METHOD
Qp=CiA
PRE-DEVELOPMENT
RAINFALL FREQ= 25 YR(DURATION=1) i=A*(Tc/60).6 (CITY OF BOZEMAN)
BASIN AREA PRE= 12.17 AC STORM EVENT STORM i COEFF INTENSITY
YR A B N/HR
PRE-DEV Tc= 25.0 MIN 2 0.36 0.6 0.61
5 0.52 0.64 0.91
PRE-DEV C= 0.20 10 0.64 0.66 1.14
25 0.79 0.64 1.37
STORM A= 0.78 50 0.92 0.66 1.64
B= 0.64 100 1.01 0.67 1.82
STORM INTENSITY= 1.37 IN/HR
PRE-DEV Qp= 3.32 CFS
POST-DEVELOPMENT
BASIN AREA POST= 12.17 AC
POST-DEV Tc= 20.0 MIN
POST-DEV C= 0.61
STORM INTENSITY= 1.58 IN/I-IR
POST-DEV Qp= 11.70 CFS
H:\1097\001\DOGS\Design\Storm\Sub C-25YR.xls 1 OF 1 PRINTED 11/5/2014
GEW 1097.001
DATE: 10/24/ 0014
ENGINEER: JRM
Subarea C-100YR
MODIFIED RATIONAL METHOD
QP=CiA
PRE-DEVELOPMENT
RAINFALL FREQ= 100 YR(DURATION=1) i=A'(Tc/60).a (CITY OF BOZEMAN)
BASIN AREA PRE= 12.17 AC STORM EVENT STORM i COEFF INTENSITY
YR _ A B IN/HR
PRE-DEV Tc= 25.0 MIN 2 0.36 0.6 0.61
5 0.52 0.64 0.91
PRE-DEV C= 0.20 10 0.64 0.66 1.14
25 0.78 0.64 1.37
STORM A= 1.01 50 0.92 0.66 1.64
B= 0.67 100 1.01 0.67 1.82
STORM INTENSITY= 1.82 IN/HR
PRE-DEV Qp= 4.42 CFS
POST-DEVELOPMENT
BASIN AREA POST= 12.17 AC
POST-DEV Tc= 20.0 MIN
POST-DEV C= 0.61
STORM INTENSITY= 2.11 IN/HR
POST-DEV Qp= 15.65 CFS
H.\1 097\00 1\DOC S\Design\Storm\Sub C-100YR.xls 1 OF 1 PRINTED: 11/5/2014
GEIN: 1097.001
DATE: 10/24/2014
ENGINEER: JRM
Subarea A+C-10YR
MODIFIED RATIONAL METHOD
Qp=CiA
PRE-DEVELOPMENT
RAINFALL FREQ= 10 YR(DURATION=1) i=A"(Tc/60).e (CITY OF BOZEMAN)
BASIN AREA PRE= 30.17 AC STORM EVENT STORM i COEFF INTENSITY
YR_ A B (IN/HR
PRE-DEV Tc= 60.0 MIN 2 0.36 0.6 0.36
5 0.52 0.64 0.52
PRE-DEV C= 0.20 10 0.64 0.66 0.64
25 0.78 0.64 0.78
STORM A= 0.64 50 0.92 0.66 0.92
B= 0.66 100 1.01 0.67 1.01
STORM INTENSITY= 0.64 IN/HR
PRE-DEV Qp= 3.86 CFS
POST-DEVELOPMENT
BASIN AREA POST= 30.17 AC
POST-DEV Tc= 60.0 MIN
POST-DEV C= 0.57
STORM INTENSITY= 0.64 IN/HR
POST-DEV Qp= 11.01 CFS
HAI097\001\ROCS\Design\Storm\SubA+C-10YR.xls 1 OF 1 PRINTED: 11(5(2014
GEIN: 1097.001
DATE: 10/24/2014
ENGINEER: JRM
Subarea A+C -25YR
MODIFIED RATIONAL METHOD
QP=CIA
PRE-DEVELOPMENT
RAINFALL FREQ= 25 YR(DURATION=1) 1=A+(Tc/60) ° (CITY OF BOZEMAN)
BASIN AREA PRE= 30.17 AC STORM EVENT STORM i COEFF INTENSITY
(YR) A B IN/HR
PRE-DEVTc= 60.0 MIN 2 0.36 0.6 0.36
5 0.52 0.64 0.52
PRE-DEV C= 0.20 10 0.64 0.66 0.64
25 0.78 0.64 0.78
STORM A= 0.78 50 0.92 0.66 0.92
B= 0.64 100 1.01 0.67 1.01
STORM INTENSITY= 0.78 IN/HR
PRE-DEV Qp= 4.71 CFS
POST-DEVELOPMENT
BASIN AREA POST= 30.17 AC
POST-DEV Tc= 60.0 MIN
POST-DEV C= 0.57
STORM INTENSITY= 0.78 IN/HR
POST-DEV Qp= 13.41 CFS
HAl097\001\DOGS\Design\Storm\Sub A+C-25YR.xis 1 OF 1 PRINTED. 11/5/2014
GEIN: 1097.001
DATE: 10/24/2014
ENGINEER: 1RM
Subarea A+C-100YR
MODIFIED RATIONAL METHOD
Qp=CiA
PRE-DEVELOPMENT
RAINFALL FREQ= 100 YR(DURATION=1) i=A*(Tc/60)'B (CITY OF BOZEMAN)
BASIN AREA PRE= 30.17 AC STORM EVENT STORM i COEFF INTENSITY
YR A IN/HR
PRE-DEVTc= 60.0 MIN 2 0.36 0.6 0.36
5 0.52 0.64 0.52
PRE-DEV C= 0.20 10 0.64 0.66 0.64
25 0.78 0.64 0.78
STORM A= 1.01 50 0.92 0.66 0.92
B= 0.67 100 1.01 0.67 1.01
STORM INTENSITY= 1.01 IN/HR
PRE•DEV Qp= 6.09 CFS
POST-DEVELOPMENT
BASIN AREA POST= 30.17 AC
POST-DEV Tc= 60.0 MIN
POST-DEV C= 0.57
STORM INTENSITY= 1.01 IN/IiR
POST-DE.V Qp= 17,37 CFS
H:\109'\001\DOCS\DesigMStorm\Sub A+C-100YR.xis 1 OF 1 PRINTED: 11/512014
GE14: 1097.001
DATE: 10/22/2014
ENGINEER: Jeremy May
Subarea C - 10Yr Regional Detention Pond NESIS
MODIFIED RATIONAL METHOD IIiNEFlC7y INC
Qp=CiA
Xir d .nAa:: tBr..zna .ti.z 5@9� -x
PRE-DEVELOPMENT
RAINFALL FREQ= 10 YR(DURATION=1) 1=A*(Tc/60)_a (CITY OF BOZEMAN)
BASIN AREA PRE= 12.17 AC STORM EVENT STORM i COEFF INTENSITY
YR _ A_ B _(IN HR
PRE-DEVTc= 25.0 MIN 2 0.36 0.6 0.61
5 0.52 0.64 0.91
PRE-DEV C= 0.20 10 0.64 0.66 1.14
25 0.78 0.64 1.37
STORM A= 0.64 50 0.92 0.66 1.64
B= 0.66 100 1.01 0.67 1.82
STORM INTENSITY= 1.14 IN/HR
PRE-DEV Qp= 2.78 CFS
POST-DEVELOPMENT POND VOLUME: CONSTAELEASE
(CF)'
BASIN AREA PRE= 12.17 AC 644383
POST-DEV Tc= 20.0 MIN TRIANGLE RELEASE
DETENTION (CF)'
POST-DEV C= 0.61 1054040
STORM INTENSITY= 1.32 IN/HR AVERAGE VOLUME
(CF)
POST-DEV Qp= 9.81 CFS 8492.12
OUTLET STRUCTURE DESIGN RETENTION
(CF)
POND: Subarea C-10Yr Regional Detention Pond 2191436
REQUIRED VOL= 8492.12 CF (AVG.R/WCONST.&TRIANGLE RELEASE)
DIAMETER= 6.00 IN
LENGTH OF PIPE= 20.00 FT QPRE= 2.78 CFS
HEAD WATER= 1.50 FT AREA= N/A SF
N= 0.012 ORIFICE= N/A IN
Ke= 0.50 ORIFICE FLOW= N/A CFS
SLOPE OF PIPE= 0.005 FT/FT
FLOW OUT= 0.98 CFS *`FLOW GOOD
AVE SURF AREA= 4295.89 SF
H:\1097\001\DOCS\Design\Storm\Sub C-Regional Storm Pond.xls 1 OF 2 PRINTED 11/5/2014
Subarea C- 10Yr Regional Detention Pond
POND VOLUME CALC'S OUTLET STRUCUTRE CALLS
Triangle Release Constant Release SLOPE OF ENERGY ORIFICE
DURATION INTENSITY Qp POND VOLUME POND VOLUME PIPE FLOW OUT
(MIN) (IN/HR) (CFS) (CF) (CF) (FT/FT) (CFS) (CFS)
19.00 1.37 10.15 8321.24 5984.46 0.000 0.936 0.741
20.00 1.32 9.81 8441.49 6052.81 0.001 0.945
21.00 1.28 9.50 8555.13 6114.02 0.002 0.954
22.00 1.24 9.21 8662.68 6168.63 0.003 0.963
23.00 1.21 8.95 8764.58 6217.14 0.004 0.972
24.00 1.17 8.70 8861.24 6259.96 0.005 0.981
25.00 1.14 8.47 8953.02 6297.49 0.006 0.990
26.00 1.11 8.25 9040.24 6330.07 0.007 0.999
27.00 1.08 3.05 9123.18 6358.00 0.008 1.008
28.00 1.06 7.96 9202.11 6381.56 0.009 1.016
29.00 1.03 7.68 9277.25 6401.00 0.010 1.025
30.00 1.01 7.51 9348.83 6416.55 0.011 1.033
31.00 0.99 7.35 9417.04 6428.43 0.012 1.042
32.00 0.97 7.19 9482.06 6436.82 0.013 1.050
33.00 0.95 7.05 9544.05 6441.90 0.014 1.058
34.00 0.93 6.91 9603.16 6443.83 0.015 1.067
35.00 0.91 6.78 9659.53 6442.77 0.016 1.075
36.00 0.90 6.66 9713.30 6438.84 0.017 1,083
37.00 0.88 6.54 9764.57 6432.19 0.018 1.091
38.00 0.87 6.42 9813.47 6422.92 0.019 1.099
39.00 0.85 6.31 9860,09 6411.16 0.020 1.107
40.00 0.84 6.21 9904.53 6396.99 0.021 1.115
41.00 0.82 6.11 9946.88 6380.53 0.022 1.123
42.00 0.81 6.01 9987.22 6361.86 0.023 1.130
43.00 0.80 S.92 10025.63 6341.07 0.024 1.138
44.00 0.79 5.83 10062.19 6318.23 0.025 1.146
45.00 0.77 5.74 10096.97 6293.42 0.026 1.153
46.00 0.76 5.66 10130.03 6266.72 0.027 1.161
47.00 0.75 5.58 10161.43 6238.19 0.028 1.168
48.00 0.74 5.51 10191.23 6207.88 0.029 1.176
49.00 0.73 5.43 10219.48 6175.87 0.030 1.183
50.00 0.72 5.36 10246.25 6142.21 0.031 1.191
51.00 0.71 5.29 10271.57 6106.95 0.032 1.198
52.00 0.70 5.22 10295.49 6070.15 0.033 1.205
53.00 0.69 5.16 10318.06 6031.84 0.034 1.213
54.00 0.69 5.09 10339.32 5992.08 0.035 1.220
55.00 0.68 5.03 10359.31 5950.91 0.036 1.227
56.00 0.67 4.97 10378.07 5908.37 0.037 1.234
57.00 0.66 4.91 10395.64 5864.51 0.038 1.241
58.00 0.65 4.86 10412.04 5819.35 0.039 1.248
59.00 0.65 4.80 10427,31 5772.94 0.040 1.255
HA1 097\001\DOC S\Design\S torm\Sub C-Regional Storm PonclAs 2 OF 2 PRINTED: 11/5/2014
Typha Court
Asphalt&Concrete 55119 sf
Roofs 28863 sf
Total 83982 sf
North of Cattail
Asphalt&Concrete 5666 sf
Roofs 5523 sf
Total 11189 sf
Cattail
L= 837
Road 35991
Sidewalk 4185
Total 40176 sf
Blackbird
L= 610
Road 20130
Sidewalk 6100
Total 26230 sf
Local ROW
L= 340
Road 10540
Sidewalk 3400
Total 13940 sf
Alley wide
1= 408
Road 12648
Sidewalk 4080
Total 17136
Alleys 19480
Townhomes 62601 sf
Drives 22440 sf
patio 5737.5 sf
back patio 4896 sf
Total 95674.5 sf
Total Impervious
308557.5 sf 7.083506
Trails 1500 gravel 0.034435
Total Acreage 12.17
C value
Impervious 7.0835055 0.9
Grass 5.0864945 0.2
Weighted:
Park 3.6 0.2
Total Area 15.77
Weighted 0.61,44232
Alley
Worksheet for Irregular Channel
Project Description
Project File h:11097i0011docstdesignlstormistreetfl.fm2
Worksheet 22'alley
Flow Element Irregular Channel
Method Manning's Formula
Solve For Dischar e
Input Data
Channel Slope 0.010000 ft/ft
Water Surface Elevation 0,33 ft
Elevation range; 0.00 ft to 0.33 ft,
Station(ft) Elevation(ft) Start Station End Station Roughness
0.00 0,33 0,00 22,00 0,016
11.00 0.00
22.00 0.33
Results
Wtd. Mannings Coefficient 0.016
Discharge 10.14 cfs
Flow Area 3.63 ft2
Wetted Perimeter 22.01 ft
Top Width 22.00 ft
Height 0.33 ft
Critical Depth 0.35 ft
Critical Slope 0.006539 ft/ft
Velocity 2,79 ft/s
Velocity Mead 0,12 ft
Specific Energy 0.45 ft
Froude Number 1.21
Flow is su ercritical.
11/05/14 FiowMaster v5.17
06:04:36 PM Haested Methods,Inc. 37 Brookside Road Waterbury.CT 06708 (203)755-1666 Page 1 of 1
32 Street Flaw - one side only
Worksheet for Irregular Channel
Project Description
Project File h:l5109710011docstdesignlstorrntstreetfi,fm2
Worksheet 32' Street Flow
Flow Element Irregular Channel
Method Manning's Formula
Solve For Discharge
Input Data
Channel Slope 0.006000 ft/ft
Water Surface Elevation 100.00 ft
Elevation range: 99.50 ft to 100.00 ft.
Station (ft) Elevation(ft) Start Station End Station Roughness
0,00 100,00 0,00 16.10 0,013
16,00 99.50
16,10 100.00
Results
Wtd. Mannings Coefficient 0.013
Discharge 13.90 cfs
Flow Area 4.03 ft2
Wetted Perimeter 16.52 ft
Top Width 16.10 ft
Height 0.50 ft
Critical Depth 100.04 ft
Critical Slope 0.003894 ft/ft
Velocity 3.45 ft/$
Velocity Head 0.19 ft
Specific Energy 100.19 ft
Froude Number 1.22
Flow is su ercritical.
11/05114 FlowMaster v5.17
06,05:41 PM Haestad Methods,Inc, 37 Brookside Road Waterbury,CT 06708 (203)7 55-1666 Page 1 of 1
40' Street Flow - one side only
Worksheet for Irregular Channel
Project Description
Project File h:110971001idocsldesignlstormtstreetfl.fm2
Worksheet 40'Street Flow
Flow Element Irregular Channel
Method Manning's Formula
Solve For Discharge
Input Data
Channel Slope 0.012000 ftlft
Water Surface Elevation 100.00 ft
Elevation range: 99,40 ft to 100.00 ft.
Station(ft) Elevation (ft) Start Station End Station Roughness
0,00 100,00 0,00 20,10 0,013
20.00 99,40
20.10 100.00
Results
Wtd. Mannings Coefficient 0.013
Discharge 33.27 cfs
Flow Area 6.03 ft2
Wetted Perimeter 20.62 ft
Top Width 20.10 ft
Height 0.60 ft
Critical Depth 100.14 ft
Critical Slope 0,003410 ft/ft
Velocity 5.52 ft/s
Velocity Head 0,47 ft
Specific Energy 100.47 ft
Froude Number 1.78
Flow is su ercritical.
1 tf05/14 FIowMaster v5.17
D6'07:14 PM Haestad Methods,Inc. 37 Brookside Road Waterbury,CT 06708 (203)755-1666 Page 1 of 1
South Swale
Worksheet for Trapezoidal Channel
Pra'ect Description
Project File h:\1097\00INdocs\design\stormNstreetfl.fm2
Worksheet South Swale
Flow Element Trapezoidal Channel
Method Manning's Formula
Solve For Dischar e
Input Data
Mannings Coefficient 0.030
Channel Slope 0,007500 ft/ft
Depth 1,00 ft
Left Side Slope 4.000000 H :V
Right Side Slope 4.000000 H :V
Bottom Width 2.00 ft
Results
Discharge 18.01 cfs
Flow Area 6.00 fe
Wetted Perimeter 10.25 ft
Top Width 10.00 ft
Critical Depth 0.83 ft
Critical Slope 0.016909 ft/ft
Velocity 3.00 ft/s
Velocity Head 0.14 ft
Specific Energy 1.14 ft
Froude Number 0.68
Flow is subcritical,
11/05/14 FlowMaster v5.17
0&07,36 PM Haestad Methods,Inc. 37 Brookside Road Waterbury,GT 06708 (203)755-1666 Page 1 of 1