HomeMy WebLinkAbout014.07 - Appendix L.9 - Flood Study Waiver Memo
MEADOW BRIDGE SUBDIVISION
Project #BOZ-05021.28
Bozeman, Montana
MARCH 2025
MEMORANDUM PAGE 1 OF 2 MARCH 2025
MEMORANDUM
To: City of Bozeman Engineering Department - Floodplain
From: Bobby Egeberg, PE - Sanbell
Date: 3/6/2025
Reference: Meadow Bridge Subdivision Preliminary Plat - Floodplain
The purpose of this Memorandum is to provide existing floodplain information within the
proposed Meadow Bridge Subdivision Preliminary Plat currently under review with the City of
Bozeman, as well as request a waiver for additional Flood Study analysis as required in BMC
38.600.150.B. The Meadow Bridge Subdivision Preliminary Plat is located within Phases II & III of
Meadow Creek Subdivision which were partially constructed including utilities, ponds, curb &
gutter, and sections of asphalt paving. The development went bankrupt in the 2008 recession, and
construction was never completed. This portion Meadow Creek Subdivision is now proposed to be
subdivided and named the Meadow Bridge Subdivision utilizing most of the infrastructure already
in place.
As part of the original Meadow Creek Subdivision analysis, a Flood Study Report was prepared by
Allied Engineering Services, Inc. in 2005/2006. A copy of the report is included in Appendix A. The
City of Bozeman should have an approved copy of the report as well in their records. Stream 2 in
the Flood Study Report is the unnamed watercourse flowing within to the proposed Meadow
Bridge Subdivision. The post development hydrology in the Flood Study Report was calculated
using three separate methods, USGS Regression, SCS Curve Number, and Rational Method.
Ultimately, the Rational Method was selected as the hydrological calculation method. The
calculated post development 100-year flow for this stream was 41.42 cfs. Sanbell utilized the USGS
StreamStats application to compare the 100-year hydrology to the values calculated in the Flood
Study Report. StreamStats is a spatial analytical tool useful for water-resources planning and
management, and for engineering and design purposes. StreamStats calculated a 100-year flow of
38.1 cfs. Therefore, the 100-year flow in the Flood Study Report is realistic and appears to be
conservative. See Appendix B for the StreamStats Report.
The Flood Study Report demonstrates all the proposed culverts will convey the 100-year flow
MEMORANDUM PAGE 2 OF 2 MARCH 2025
without overtopping of roadways, and without exceeding the maximum headwater depth allowed
by the City of Bozeman of 1.5 times the diameter of the pipe. There are three (3) exiting 36-inch
equivalent arch reinforced concrete pipes within the proposed Meadow Bridge Subdivision
crossing Blackwood Road, Kurk Drive (identified as Ainsworth Drive in the record drawings), and
Parkway Avenue. In addition to the analysis provided in the Flood Study Report, Sanbell completed
an independent hydraulic capacity calculation of the culvert crossings utilizing FHWA HY-8
software. The HY-8 analysis was based on the record drawings of three (3) existing culvert
crossings and our results confirm the conclusions in the Flood Study Report. See Appendix C for
the record drawings of the culvert crossings and HY-8 output.
Based on the existing Flood Study Report prepared by Allied Engineering Services, Inc. and the
additional analysis prepared by Sanbell and presented in this Memorandum, we are requesting a
waiver of BMC 38.600.150.B. requiring another flood study be prepared for the Meadow Bridge
Subdivision Preliminary Plat. The existing Flood Study Report and additional analysis provide
sufficient information to determine flood risk within the proposed subdivision and demonstrate
that flood risk is sufficiently mitigated by the existing infrastructure.
APPENDICES
APPENDIX A – FLOOD STUDY REPORT – ALLIED ENGINEERING
APPENDIX B – STREAMSTATS REPORT
APPENDIX C – CULVERT CROSSING RECORD DRAWINGS & HY-8 RESULTS
MEADOW BRIDGE SUBDIVISION
Project #BOZ-05021.28
APPENDIX A FLOOD STUDY REPORT ALLIED ENGINEERING
MEADOW BRIDGE SUBDIVISION
Project #BOZ-05021.28
APPENDIX B STREAMSTATS REPORT
Middle Creek StreamStats Report
Collapse All
Basin Characteristics
Parameter Code Parameter Description Value Unit
CHANWD_RS Channel width determined from remotely sensed data sources, including aerial imagery 0 feet
CONTDA Area that contributes flow to a point on a stream 0.1 square miles
DRNAREA Area that drains to a point on a stream 0.1 square miles
EL6000 Percent of area above 6000 ft 0 percent
WACTCH Width of active channel 0 feet
WBANKFULL Width of channel at bankfull 0 feet
Peak-Flow Statistics
Peak-Flow Statistics Parameters [UpYellow CentMount Region BasinC 2015 5019F]
Parameter Code Parameter Name Value Units Min Limit Max Limit
CONTDA Contributing Drainage Area 0.1 square miles 0.39 2040
EL6000 Percent above 6000 ft 0 percent 0 100
Peak-Flow Statistics Parameters [UpYllw CentMount Region Act Channel SIR 2020 5142]
Parameter Code Parameter Name Value Units Min Limit Max Limit
WACTCH Width Of Active Channel 0 feet 1 150
Region ID:MT
Workspace ID:MT20250204172337277000
Clicked Point (Latitude, Longitude):45.64225, -111.06890
NHD Stream GNIS Name of Click Point: Middle Creek Ditch
Time:2025-02-04 10:24:09 -0700
Peak-Flow Statistics Parameters [UpYllw CentMount Region Bankfull SIR 2020 5142]
Parameter Code Parameter Name Value Units Min Limit Max Limit
WBANKFULL Width Of Bankfull Channel 0 feet 2.5 170
Peak-Flow Statistics Parameters [UpYllw CentMount Region Aerial Photo SIR 2020 5142]
Parameter Code Parameter Name Value Units Min Limit Max Limit
CHANWD_RS Channel_Width_remotely_sensed 0 feet 2.3 191.9
Peak-Flow Statistics Disclaimers [UpYellow CentMount Region BasinC 2015 5019F]
One or more of the parameters is outside the suggested range. Estimates were extrapolated with unknown errors.
Peak-Flow Statistics Flow Report [UpYellow CentMount Region BasinC 2015 5019F]
Statistic Value Unit
66.7-percent AEP flood 0.411 ft^3/s
50-percent AEP flood 0.746 ft^3/s
42.9-percent AEP flood 1.03 ft^3/s
20-percent AEP flood 3.47 ft^3/s
10-percent AEP flood 7.46 ft^3/s
4-percent AEP flood 16 ft^3/s
2-percent AEP flood 25.7 ft^3/s
1-percent AEP flood 38.1 ft^3/s
0.5-percent AEP flood 54.4 ft^3/s
0.2-percent AEP flood 82.5 ft^3/s
Peak-Flow Statistics Disclaimers [UpYllw CentMount Region Act Channel SIR 2020 5142]
One or more of the parameters is outside the suggested range. Estimates were extrapolated with unknown errors.
Peak-Flow Statistics Flow Report [UpYllw CentMount Region Act Channel SIR 2020 5142]
Statistic Value Unit
Active chan width 66.7 percent AEP flood 0 ft^3/s
Active Channel Width 50-percent AEP flood 0 ft^3/s
Active chan width 42.9 percent AEP flood 0 ft^3/s
Active Channel Width 20-percent AEP flood 0 ft^3/s
Active Channel Width 10-percent AEP flood 0 ft^3/s
Active Channel Width 4-percent AEP flood 0 ft^3/s
Active Channel Width 2-percent AEP flood 0 ft^3/s
Active Channel Width 1-percent AEP flood 0 ft^3/s
Active Channel Width 0.5-percent AEP flood 0 ft^3/s
Active Channel Width 0.2-percent AEP flood 0 ft^3/s
Peak-Flow Statistics Disclaimers [UpYllw CentMount Region Bankfull SIR 2020 5142]
One or more of the parameters is outside the suggested range. Estimates were extrapolated with unknown errors.
Peak-Flow Statistics Flow Report [UpYllw CentMount Region Bankfull SIR 2020 5142]
Statistic Value Unit
Bankfull width 66.7 percent AEP flood 0 ft^3/s
Bankfull Width 50-percent AEP flood 0 ft^3/s
Bankfull width 42.9 percent AEP flood 0 ft^3/s
Bankfull Width 20-percent AEP flood 0 ft^3/s
Bankfull Width 10-percent AEP flood 0 ft^3/s
Bankfull Width 4-percent AEP flood 0 ft^3/s
Bankfull Width 2-percent AEP flood 0 ft^3/s
Bankfull Width 1-percent AEP flood 0 ft^3/s
Bankfull Width 0.5-percent AEP flood 0 ft^3/s
Bankfull Width 0.2-percent AEP flood 0 ft^3/s
Peak-Flow Statistics Disclaimers [UpYllw CentMount Region Aerial Photo SIR 2020 5142]
One or more of the parameters is outside the suggested range. Estimates were extrapolated with unknown errors.
Peak-Flow Statistics Flow Report [UpYllw CentMount Region Aerial Photo SIR 2020 5142]
Statistic Value Unit
Rem sens chan width 66.7 percent AEP fld 0 ft^3/s
Rem_sens_chan_width_50_percent_AEP_flood 0 ft^3/s
Rem sens chan width 42.9 percent AEP fld 0 ft^3/s
Rem_sens_chan_width_20_percent_AEP_flood 0 ft^3/s
Rem_sens_chan_width_10_percent_AEP_flood 0 ft^3/s
Rem_sens_chan_width_4_percent_AEP_flood 0 ft^3/s
Rem_sens_chan_width_2_percent_AEP_flood 0 ft^3/s
Rem_sens_chan_width_1_percent_AEP_flood 0 ft^3/s
Rem_sens_chan_width_0_5_pct_AEP_flood 0 ft^3/s
Rem_sens_chan_width_0_2_pct_AEP_flood 0 ft^3/s
Peak-Flow Statistics Flow Report [Area-Averaged]
Statistic Value Unit
66.7-percent AEP flood 0.411 ft^3/s
50-percent AEP flood 0.746 ft^3/s
42.9-percent AEP flood 1.03 ft^3/s
20-percent AEP flood 3.47 ft^3/s
10-percent AEP flood 7.46 ft^3/s
4-percent AEP flood 16 ft^3/s
2-percent AEP flood 25.7 ft^3/s
1-percent AEP flood 38.1 ft^3/s
0.5-percent AEP flood 54.4 ft^3/s
0.2-percent AEP flood 82.5 ft^3/s
Active chan width 66.7 percent AEP flood 0 ft^3/s
Active Channel Width 50-percent AEP flood 0 ft^3/s
Statistic Value Unit
Active chan width 42.9 percent AEP flood 0 ft^3/s
Active Channel Width 20-percent AEP flood 0 ft^3/s
Active Channel Width 10-percent AEP flood 0 ft^3/s
Active Channel Width 4-percent AEP flood 0 ft^3/s
Active Channel Width 2-percent AEP flood 0 ft^3/s
Active Channel Width 1-percent AEP flood 0 ft^3/s
Active Channel Width 0.5-percent AEP flood 0 ft^3/s
Active Channel Width 0.2-percent AEP flood 0 ft^3/s
Bankfull width 66.7 percent AEP flood 0 ft^3/s
Bankfull Width 50-percent AEP flood 0 ft^3/s
Bankfull width 42.9 percent AEP flood 0 ft^3/s
Bankfull Width 20-percent AEP flood 0 ft^3/s
Bankfull Width 10-percent AEP flood 0 ft^3/s
Bankfull Width 4-percent AEP flood 0 ft^3/s
Bankfull Width 2-percent AEP flood 0 ft^3/s
Bankfull Width 1-percent AEP flood 0 ft^3/s
Bankfull Width 0.5-percent AEP flood 0 ft^3/s
Bankfull Width 0.2-percent AEP flood 0 ft^3/s
Rem sens chan width 66.7 percent AEP fld 0 ft^3/s
Rem_sens_chan_width_50_percent_AEP_flood 0 ft^3/s
Rem sens chan width 42.9 percent AEP fld 0 ft^3/s
Rem_sens_chan_width_20_percent_AEP_flood 0 ft^3/s
Rem_sens_chan_width_10_percent_AEP_flood 0 ft^3/s
Rem_sens_chan_width_4_percent_AEP_flood 0 ft^3/s
Rem_sens_chan_width_2_percent_AEP_flood 0 ft^3/s
Rem_sens_chan_width_1_percent_AEP_flood 0 ft^3/s
Rem_sens_chan_width_0_5_pct_AEP_flood 0 ft^3/s
Rem_sens_chan_width_0_2_pct_AEP_flood 0 ft^3/s
Peak-Flow Statistics Citations
Sando, Roy, Sando, S.K., McCarthy, P.M., and Dutton, D.M.,2016, Methods for estimating peak-flow frequencies at ungaged sites in
Montana based on data through water year 2011: U.S. Geological Survey Scientific Investigations Report 2015–5019–F, 30 p.
(https://doi.org/10.3133/sir20155019)
Chase, K.J., Sando, R., Armstrong, D.W., and McCarthy, P., 2021, Regional regression equations based on channel-width
characteristics to estimate peak-flow frequencies at ungaged sites in Montana using peak-flow frequency data through water year
2011 (ver. 1.1, September 2021): U.S. Geological Survey Scientific Investigations Report 2020–5142, 49 p.
(https://doi.org/10.3133/sir20205142)
NHD Features of Delineated Basin
NHD Streams Intersecting Basin Delineation Boundary
This functionality attempts to find the stream name at the delineation point. The name of the nearest intersecting National Hydrography Dataset (NHD)
stream is selected by default to appear in the report above. NHD streams do not correspond to the StreamStats stream grid and may not be accurate. If
you would like a different stream to appear in the above section, please make a selection below.
GNIS ID GNIS Name Distance from Clicked Point (ft)Feature Type Selected Stream Name
00787233 Middle Creek Ditch 3,191.31 Canal Ditch
Watershed Boundary Dataset (WBD) HUC 8 Intersecting Basin Delineation Boundary
This functionality attempts to find the intersecting HUC 8 of the delineated watershed. HUC boundaries do not correspond to the StreamStats data and
may not be accurate.
HUC 8 Name
10020008 Gallatin
NHD Hydrologic Features Citations
U.S. Geological Survey, 2022, USGS TNM - National Hydrography Dataset, accessed July 21, 2022 at URL
https://hydro.nationalmap.gov/arcgis/rest/services/nhd/MapServer/6.
(https://hydro.nationalmap.gov/arcgis/rest/services/nhd/MapServer/6) U.S. Geological Survey, 2022, USGS TNM - National
Hydrography Dataset, accessed July 21, 2022 at URL https://hydro.nationalmap.gov/arcgis/rest/services/wbd/MapServer/4.
(https://hydro.nationalmap.gov/arcgis/rest/services/wbd/MapServer/4)
Channel-width Methods Weighting
No method weighting results returned.
USGS Data Disclaimer: Unless otherwise stated, all data, metadata and related materials are considered to satisfy the quality standards relative to the purpose for which
the data were collected. Although these data and associated metadata have been reviewed for accuracy and completeness and approved for release by the U.S. Geological
Survey (USGS), no warranty expressed or implied is made regarding the display or utility of the data for other purposes, nor on all computer systems, nor shall the act of
distribution constitute any such warranty.
USGS Software Disclaimer: This software has been approved for release by the U.S. Geological Survey (USGS). Although the software has been subjected to rigorous review,
the USGS reserves the right to update the software as needed pursuant to further analysis and review. No warranty, expressed or implied, is made by the USGS or the U.S.
Government as to the functionality of the software and related material nor shall the fact of release constitute any such warranty. Furthermore, the software is released on
condition that neither the USGS nor the U.S. Government shall be held liable for any damages resulting from its authorized or unauthorized use.
USGS Product Names Disclaimer: Any use of trade, firm, or product names is for descriptive purposes only and does not imply endorsement by the U.S. Government.
Application Version: 4.26.0
StreamStats Services Version: 1.2.22
NSS Services Version: 2.2.1
Middle Creek Ditch
MEADOW BRIDGE SUBDIVISION
Project #BOZ-05021.28
APPENDIX C CULVERT CROSSING RECORD DRAWINGS & HY-8 RESULTS
HY-8 Culvert Analysis Report
Crossing Discharge Data
Discharge Selection Method: Specify Minimum, Design, and Maximum Flow
Minimum Flow: 7.46 cfs
Design Flow: 16.00 cfs
Maximum Flow: 41.42 cfs
Table 1 - Summary of Culvert Flows at Crossing: Blackwood RD
Headwater
Elevation (ft)
Total
Discharge
(cfs)
Culvert 1
Discharge
(cfs)
Roadway
Discharge
(cfs)
Iterations
17.93 7.46 7.46 0.00 1
18.14 10.86 10.86 0.00 1
18.36 14.25 14.25 0.00 1
18.47 16.00 16.00 0.00 1
18.79 21.04 21.04 0.00 1
19.02 24.44 24.44 0.00 1
19.25 27.84 27.84 0.00 1
19.49 31.23 31.23 0.00 1
19.74 34.63 34.63 0.00 1
20.00 38.02 38.02 0.00 1
20.28 41.42 41.42 0.00 1
22.00 58.91 58.91 0.00 Overtopping
Rating Curve Plot for Crossing: Blackwood RD
Culvert Data: Culvert 1
Table 1 - Culvert Summary Table: Culvert 1
Total
Disch
arge
(cfs)
Culve
rt
Disch
arge
(cfs)
Head
water
Elevat
ion
(ft)
Inle
t
Cont
rol
Dep
th
(ft)
Outl
et
Cont
rol
Dep
th
(ft)
Fl
ow
Ty
pe
Nor
mal
Dep
th
(ft)
Criti
cal
Dep
th
(ft)
Out
let
De
pth
(ft)
Tailw
ater
Dept
h (ft)
Outl
et
Velo
city
(ft/s
)
Tailw
ater
Veloc
ity
(ft/s)
7.46
cfs
7.46
cfs
17.93 0.87 0.0* 1-
JS1
t
0.42 0.63 1.0
6
1.06 2.21 2.38
10.86
cfs
10.86
cfs
18.14 1.08 0.0* 1-
S2
n
0.51 0.77 0.5
1
1.15 7.74 2.40
14.25
cfs
14.25
cfs
18.36 1.30 0.0* 1-
S2
n
0.58 0.90 0.5
8
1.21 8.49 2.49
16.00
cfs
16.00
cfs
18.47 1.41 0.0* 1-
S2
n
0.62 0.96 0.6
3
1.24 8.65 2.54
21.04
cfs
21.04
cfs
18.79 1.73 0.0* 1-
S2
n
0.72 1.12 0.7
4
1.30 9.43 2.67
24.44
cfs
24.44
cfs
19.02 1.96 0.0* 1-
S2
n
0.79 1.22 0.8
2
1.34 9.69 2.75
27.84
cfs
27.84
cfs
19.25 2.19 0.20
0
1-
S2
n
0.85 1.32 0.8
5
1.37 10.5
5
2.83
31.23
cfs
31.23
cfs
19.49 2.43 0.43
0
5-
S2
n
0.91 1.41 0.9
5
1.40 10.4
4
2.90
34.63
cfs
34.63
cfs
19.74 2.68 0.72
6
5-
S2
n
0.97 1.49 1.0
1
1.43 10.8
1
2.96
38.02
cfs
38.02
cfs
20.00 2.94 1.03
9
5-
S2
n
1.03 1.57 1.0
7
1.45 11.0
8
3.02
41.42
cfs
41.42
cfs
20.28 3.22 1.36
8
5-
S2
n
1.09 1.65 1.1
4
1.48 11.3
0
3.08
* Full Flow Headwater elevation is below inlet invert.
Culvert Barrel Data
Culvert Barrel Type Straight Culvert
Inlet Elevation (invert): 17.06 ft,
Outlet Elevation (invert): 15.16 ft
Culvert Length: 108.02 ft,
Culvert Slope: 0.0176
Culvert Performance Curve Plot: Culvert 1
Water Surface Profile Plot for Culvert: Culvert 1
Site Data - Culvert 1
Site Data Option: Culvert Invert Data
Inlet Station: 0.00 ft
Inlet Elevation: 17.06 ft
Outlet Station: 108.00 ft
Outlet Elevation: 15.16 ft
Number of Barrels: 1
Culvert Data Summary - Culvert 1
Barrel Shape: Pipe Arch
Barrel Span: 43.75 in
Barrel Rise: 26.62 in
Barrel Material: Concrete
Embedment: 0.00 in
Barrel Manning's n: 0.0130
Culvert Type: Straight
Inlet Configuration: Square Edge with Headwall (Ke=0.5)
Inlet Depression: None
Tailwater Data for Crossing: Blackwood RD
Table 2 - Downstream Channel Rating Curve (Crossing: Blackwood RD)
Flow (cfs) Water
Surface
Elev (ft)
Velocity
(ft/s)
Depth (ft) Shear (psf) Froude
Number
7.46 16.22 1.06 2.38 0.99 0.83
10.86 16.31 1.15 2.40 1.07 0.84
14.25 16.37 1.21 2.49 1.13 0.85
16.00 16.40 1.24 2.54 1.16 0.85
21.04 16.46 1.30 2.67 1.22 0.86
24.44 16.50 1.34 2.75 1.25 0.87
27.84 16.53 1.37 2.83 1.28 0.88
31.23 16.56 1.40 2.90 1.31 0.88
34.63 16.59 1.43 2.96 1.33 0.89
38.02 16.61 1.45 3.02 1.36 0.89
41.42 16.64 1.48 3.08 1.38 0.90
Tailwater Channel Data - Blackwood RD
Tailwater Channel Option: Irregular Channel
Channel Slope: Irregular Channel
User Defined Channel Cross-Section
Coord No. Station (ft) Elevation (ft) Manning's n
1 0.00 18.78 0.0300
2 62.84 16.18 0.0300
3 65.11 15.16 0.0300
4 66.71 15.99 0.0300
5 141.09 18.19 0.0000
Roadway Data for Crossing: Blackwood RD
Roadway Profile Shape: Constant Roadway Elevation
Crest Length: 200.00 ft
Crest Elevation: 22.00 ft
Roadway Surface: Paved
Roadway Top Width: 30.00 ft
Crossing Discharge Data
Discharge Selection Method: Specify Minimum, Design, and Maximum Flow
Minimum Flow: 7.46 cfs
Design Flow: 16.00 cfs
Maximum Flow: 41.42 cfs
Table 3 - Summary of Culvert Flows at Crossing: Ainsworth DR
Headwater
Elevation (ft)
Total
Discharge
(cfs)
Culvert 2
Discharge
(cfs)
Roadway
Discharge
(cfs)
Iterations
97.37 7.46 7.46 0.00 1
97.58 10.86 10.86 0.00 1
97.79 14.25 14.25 0.00 1
97.91 16.00 16.00 0.00 1
98.23 21.04 21.04 0.00 1
98.45 24.44 24.44 0.00 1
98.69 27.84 27.84 0.00 1
98.93 31.23 31.23 0.00 1
99.18 34.63 34.63 0.00 1
99.44 38.02 38.02 0.00 1
99.72 41.42 41.42 0.00 1
102.00 63.67 63.67 0.00 Overtopping
Rating Curve Plot for Crossing: Ainsworth DR
Culvert Data: Culvert 2
Table 2 - Culvert Summary Table: Culvert 2
Total
Disch
arge
(cfs)
Culve
rt
Disch
arge
(cfs)
Head
water
Elevat
ion
(ft)
Inle
t
Cont
rol
Dep
th
(ft)
Outl
et
Cont
rol
Dep
th
(ft)
Fl
ow
Ty
pe
Nor
mal
Dep
th
(ft)
Criti
cal
Dep
th
(ft)
Out
let
De
pth
(ft)
Tailw
ater
Dept
h (ft)
Outl
et
Velo
city
(ft/s
)
Tailw
ater
Veloc
ity
(ft/s)
7.46
cfs
7.46
cfs
97.37 0.88 0.0* 1-
S2
n
0.46 0.63 0.4
6
0.61 6.03 2.71
10.86
cfs
10.86
cfs
97.58 1.09 0.0* 1-
S2
n
0.56 0.77 0.5
6
0.70 6.86 2.98
14.25
cfs
14.25
cfs
97.79 1.30 0.0* 1-
S2
n
0.64 0.90 0.6
4
0.78 7.52 3.18
16.00
cfs
16.00
cfs
97.91 1.42 0.0* 1-
S2
n
0.69 0.96 0.6
9
0.81 7.81 3.28
21.04
cfs
21.04
cfs
98.23 1.74 0.26
5
1-
S2
n
0.80 1.12 0.8
1
0.91 8.37 3.43
24.44
cfs
24.44
cfs
98.45 1.96 0.51
0
1-
S2
n
0.88 1.22 0.8
9
0.98 8.75 3.36
27.84
cfs
27.84
cfs
98.69 2.20 0.77
0
1-
S2
n
0.95 1.32 0.9
7
1.05 9.05 3.28
31.23
cfs
31.23
cfs
98.93 2.44 1.04
7
5-
S2
n
1.02 1.41 1.0
4
1.10 9.36 3.21
34.63
cfs
34.63
cfs
99.18 2.69 1.34
0
5-
S2
n
1.09 1.49 1.1
2
1.14 9.62 3.19
38.02
cfs
38.02
cfs
99.44 2.95 1.65
0
5-
S2
n
1.17 1.57 1.2
0
1.18 9.86 3.20
41.42
cfs
41.42
cfs
99.72 3.23 1.97
6
5-
S2
n
1.24 1.65 1.2
7
1.21 10.0
7
3.22
* Full Flow Headwater elevation is below inlet invert.
Culvert Barrel Data
Culvert Barrel Type Straight Culvert
Inlet Elevation (invert): 96.49 ft,
Outlet Elevation (invert): 95.22 ft
Culvert Length: 104.01 ft,
Culvert Slope: 0.0122
Culvert Performance Curve Plot: Culvert 2
Water Surface Profile Plot for Culvert: Culvert 2
Site Data - Culvert 2
Site Data Option: Culvert Invert Data
Inlet Station: 0.00 ft
Inlet Elevation: 96.49 ft
Outlet Station: 104.00 ft
Outlet Elevation: 95.22 ft
Number of Barrels: 1
Culvert Data Summary - Culvert 2
Barrel Shape: Pipe Arch
Barrel Span: 43.75 in
Barrel Rise: 26.62 in
Barrel Material: Concrete
Embedment: 0.00 in
Barrel Manning's n: 0.0130
Culvert Type: Straight
Inlet Configuration: Square Edge with Headwall (Ke=0.5)
Inlet Depression: None
Tailwater Data for Crossing: Ainsworth DR
Table 4 - Downstream Channel Rating Curve (Crossing: Ainsworth DR)
Flow (cfs) Water
Surface
Elev (ft)
Velocity
(ft/s)
Depth (ft) Shear (psf) Froude
Number
7.46 95.83 0.61 2.71 0.57 0.86
10.86 95.92 0.70 2.98 0.66 0.88
14.25 96.00 0.78 3.18 0.73 0.90
16.00 96.03 0.81 3.28 0.76 0.91
21.04 96.13 0.91 3.43 0.85 0.92
24.44 96.20 0.98 3.36 0.92 0.91
27.84 96.27 1.05 3.28 0.98 0.91
31.23 96.32 1.10 3.21 1.03 0.91
34.63 96.36 1.14 3.19 1.07 0.91
38.02 96.40 1.18 3.20 1.10 0.91
41.42 96.43 1.21 3.22 1.13 0.91
Tailwater Channel Data - Ainsworth DR
Tailwater Channel Option: Irregular Channel
Channel Slope: Irregular Channel
User Defined Channel Cross-Section
Coord No. Station (ft) Elevation (ft) Manning's n
1 44.14 97.55 0.0300
2 99.23 96.24 0.0300
3 112.85 95.22 0.0300
4 114.08 96.11 0.0300
5 180.74 98.24 0.0000
Roadway Data for Crossing: Ainsworth DR
Roadway Profile Shape: Constant Roadway Elevation
Crest Length: 200.00 ft
Crest Elevation: 102.00 ft
Roadway Surface: Paved
Roadway Top Width: 30.00 ft
Crossing Discharge Data
Discharge Selection Method: Specify Minimum, Design, and Maximum Flow
Minimum Flow: 7.46 cfs
Design Flow: 16.00 cfs
Maximum Flow: 41.42 cfs
Table 5 - Summary of Culvert Flows at Crossing: Parkway AVE
Headwater
Elevation (ft)
Total
Discharge
(cfs)
Culvert 3
Discharge
(cfs)
Roadway
Discharge
(cfs)
Iterations
82.98 7.46 7.46 0.00 1
83.19 10.86 10.86 0.00 1
83.41 14.25 14.25 0.00 1
83.52 16.00 16.00 0.00 1
83.84 21.04 21.04 0.00 1
84.07 24.44 24.44 0.00 1
84.30 27.84 27.84 0.00 1
84.54 31.23 31.23 0.00 1
84.79 34.63 34.63 0.00 1
85.05 38.02 38.02 0.00 1
85.33 41.42 41.42 0.00 1
88.00 66.72 66.72 0.00 Overtopping
Rating Curve Plot for Crossing: Parkway AVE
Culvert Data: Culvert 3
Table 3 - Culvert Summary Table: Culvert 3
Total
Disch
arge
(cfs)
Culve
rt
Disch
arge
(cfs)
Head
water
Elevat
ion
(ft)
Inle
t
Cont
rol
Dep
th
(ft)
Outl
et
Cont
rol
Dep
th
(ft)
Fl
ow
Ty
pe
Nor
mal
Dep
th
(ft)
Criti
cal
Dep
th
(ft)
Out
let
De
pth
(ft)
Tailw
ater
Dept
h (ft)
Outl
et
Velo
city
(ft/s
)
Tailw
ater
Veloc
ity
(ft/s)
7.46
cfs
7.46
cfs
82.98 0.87 0.0* 1-
S2
n
0.42 0.63 0.4
2
0.67 6.83 2.69
10.86
cfs
10.86
cfs
83.19 1.08 0.0* 1-
S2
n
0.51 0.77 0.5
1
0.76 7.76 2.90
14.25
cfs
14.25
cfs
83.41 1.30 0.0* 1-
S2
n
0.58 0.90 0.5
8
0.83 8.51 3.08
16.00
cfs
16.00
cfs
83.52 1.41 0.0* 1-
S2
n
0.62 0.96 0.6
2
0.87 8.85 3.16
21.04
cfs
21.04
cfs
83.84 1.73 0.0* 1-
S2
n
0.72 1.12 0.7
3
0.95 9.47 3.36
24.44
cfs
24.44
cfs
84.07 1.96 0.0* 1-
S2
n
0.78 1.22 0.8
1
1.00 9.76 3.48
27.84
cfs
27.84
cfs
84.30 2.19 0.01
1
1-
S2
n
0.85 1.32 0.8
5
1.05 10.5
9
3.59
31.23
cfs
31.23
cfs
84.54 2.43 0.29
5
5-
S2
n
0.91 1.41 0.9
4
1.09 10.5
2
3.69
34.63
cfs
34.63
cfs
84.79 2.68 0.59
7
5-
S2
n
0.97 1.49 1.0
0
1.13 10.9
4
3.78
38.02
cfs
38.02
cfs
85.05 2.94 0.91
7
5-
S2
n
1.03 1.57 1.0
7
1.16 11.1
3
3.86
41.42
cfs
41.42
cfs
85.33 3.22 1.25
4
5-
S2
n
1.09 1.65 1.1
3
1.20 11.3
7
3.94
* Full Flow Headwater elevation is below inlet invert.
Culvert Barrel Data
Culvert Barrel Type Straight Culvert
Inlet Elevation (invert): 82.11 ft,
Outlet Elevation (invert): 80.05 ft
Culvert Length: 116.02 ft,
Culvert Slope: 0.0178
Culvert Performance Curve Plot: Culvert 3
Water Surface Profile Plot for Culvert: Culvert 3
Site Data - Culvert 3
Site Data Option: Culvert Invert Data
Inlet Station: 0.00 ft
Inlet Elevation: 82.11 ft
Outlet Station: 116.00 ft
Outlet Elevation: 80.05 ft
Number of Barrels: 1
Culvert Data Summary - Culvert 3
Barrel Shape: Pipe Arch
Barrel Span: 43.75 in
Barrel Rise: 26.62 in
Barrel Material: Concrete
Embedment: 0.00 in
Barrel Manning's n: 0.0130
Culvert Type: Straight
Inlet Configuration: Square Edge with Headwall (Ke=0.5)
Inlet Depression: None
Tailwater Data for Crossing: Parkway AVE
Table 6 - Downstream Channel Rating Curve (Crossing: Parkway AVE)
Flow (cfs) Water
Surface
Elev (ft)
Velocity
(ft/s)
Depth (ft) Shear (psf) Froude
Number
7.46 80.72 0.67 2.69 0.62 0.87
10.86 80.81 0.76 2.90 0.71 0.88
14.25 80.88 0.83 3.08 0.78 0.90
16.00 80.92 0.87 3.16 0.81 0.90
21.04 81.00 0.95 3.36 0.89 0.92
24.44 81.05 1.00 3.48 0.94 0.93
27.84 81.10 1.05 3.59 0.98 0.93
31.23 81.14 1.09 3.69 1.02 0.94
34.63 81.18 1.13 3.78 1.05 0.95
38.02 81.21 1.16 3.86 1.09 0.95
41.42 81.25 1.20 3.94 1.12 0.96
Tailwater Channel Data - Parkway AVE
Tailwater Channel Option: Irregular Channel
Channel Slope: Irregular Channel
User Defined Channel Cross-Section
Coord No. Station (ft) Elevation (ft) Manning's n
1 0.00 83.55 0.0300
2 30.00 80.55 0.0300
3 33.00 80.05 0.0300
4 36.00 80.55 0.0300
5 66.00 83.55 0.0000
Roadway Data for Crossing: Parkway AVE
Roadway Profile Shape: Constant Roadway Elevation
Crest Length: 200.00 ft
Crest Elevation: 88.00 ft
Roadway Surface: Paved
Roadway Top Width: 30.00 ft