HomeMy WebLinkAbout46_Flood Hazard Eval
Flood Hazard Evaluation Report
Baxter Creek
Urban Farm Phase 2
Northwest of Huffine Ln & S Cottonwood Rd Intersection
Gallatin County, Montana
November, 2023
Prepared By:
Hyalite Engineers, PLLC
2304 N 7th Ave. Suite L
Bozeman, MT 59715
11/16/2023
BAXTER CREEK FLOOD STUDY – Bozeman, MT
Table of Contents Page ii
Version 11/15/2023
Table of Contents
Table of Contents ........................................................................................................................ ii
List of Appendices ...................................................................................................................... iii
1 Introduction ...................................................................................................................... 1-1
1.1 Purpose of Report ..................................................................................................... 1-1
1.2 Overview ................................................................................................................... 1-2
2 Location and Site Information .......................................................................................... 2-1
2.1 Location .................................................................................................................... 2-1
2.2 Local Topography ..................................................................................................... 2-1
2.3 Site Geology and Soil Conditions .............................................................................. 2-2
2.4 Regional Groundwater Conditions ............................................................................ 2-2
3 Hydrologic Analysis.......................................................................................................... 3-3
3.1 General Hydrologic Information and Basin Description ............................................. 3-3
3.2 Floodplain Characteristics ......................................................................................... 3-3
3.3 Determination of 100-year Flows .............................................................................. 3-3
3.4 Flow Contribution from Up-Gradient Hydraulic Structures ......................................... 3-4
3.5 Total Flows Used in Hydraulic Modeling ................................................................... 3-4
4 Hydraulic Analysis ........................................................................................................... 4-5
4.1 Hydraulic Analysis and Methodology ........................................................................ 4-5
4.2 HEC RAS 2D Modeling Analysis & Assumptions ...................................................... 4-5
4.3 Discussion of Results ................................................................................................ 4-7
5 Study Limitations ............................................................................................................. 5-1
References ............................................................................................................................. 5-2
BAXTER CREEK FLOOD STUDY – Bozeman, MT
List of Appendices Page iii
Version 11/15/2023
List of Figures
Figure 1 - Study area (project site) map. ................................................................................ 2-1
Figure 2 - Flow hydrograph used in the hydraulic analysis. .................................................... 3-4
Figure 3 - Overview of existing conditions model geometry. Flow boundaries IN
and OUT noted. Computational mesh does not cover areas where no
flow is calculated. ................................................................................................... 4-6
Figure 4 - Overview of proposed conditions model geometry. Flow boundaries IN
and OUT noted. Computational mesh does not cover areas where no
flow is calculated. ................................................................................................... 4-6
Figure 5 - Existing condition results map showing maximum flood depths. ............................ 4-7
Figure 6 - Proposed condition results map showing maximum flood depths. .......................... 4-8
List of Appendices
Appendix A – Flood Mapping
Appendix B – Basin Map
Appendix C – Hydrology Calculations
Appendix D – Farmers Canal Headgate Calculations
BAXTER CREEK FLOOD STUDY – Bozeman, MT
Introduction Page 1-1
Version 11/15/2023
1 Introduction
1.1 Purpose of Report
Per Section 38.600.150 of the City of Bozeman Code of Ordinances 2023:
B. If any portion of a proposed development contains a watercourse or drainway draining an area less than 25
square miles, and regulated flood hazard areas under BMC section 38.600.110 have not been designated or
identified, then, except as provided in subsection B.1 of this section, the development applicant shall prepare
a flood hazard evaluation report in conformance with subsection C of this section, which shall be provided
with a preliminary plat or site plan application.
1. The requirement to provide a flood hazard evaluation report may be waived by the floodplain
administrator if the development applicant demonstrates to the satisfaction of the floodplain
administrator that the base flood discharge of the watercourse will not adversely affect the land
proposed for development at the time of concept site plan or subdivision pre-application plan.
C. Contents of the flood hazard evaluation report shall include the following information at a minimum:
1. Certification by a professional engineer that the flood hazard evaluation report is prepared in
accordance with this section;
2. Description of any mitigation required to protect the proposed development and adjacent lands from
100-year flood hazards;
3. Scaled plan view exhibit(s) showing the following: watercourses and drainways, property boundaries,
existing topographic contours, proposed grading and drainage contours, existing (pre-project) 100-year
floodplain boundary, proposed (post-project) 100-year floodplain boundary, and proposed project
improvements. Exhibit(s) shall be neat and orderly and contain a linetype legend, north arrow, and
drawing scale;
4. Hydrologic analysis performed in accordance with standard engineering practices containing at a
minimum: exhibit(s) depicting delineation of overall contributing drainage basin and individual sub-
basins, determination of base flood discharge, narrative describing the basin delineation approach and
hydrologic method(s) used in discharge determination, and any supporting digital files and outputs
produced for the hydrologic analysis;
5. Hydraulic analysis performed in accordance with standard engineering practices containing at a
minimum: hydraulic modeling of the base flood discharge for existing conditions (pre-project) and
proposed conditions (post-project), scaled plan view exhibit(s) depicting modeled cross sections,
narrative describing hydraulic model development and data sources used for critical inputs, description
of existing and proposed hydraulic structures, model outputs of water surface elevation in both profile
and cross section view, and digital model files; and
6. The report shall be formatted as a PDF document and include all digital supporting files.
The purpose of this report is to present hydraulic modeling that defines the 100-year floodplain
boundaries for Baxter Creek within the defined study area per the above requirement. The authors
of this report hereby certify general conformance to the above. This study has been prepared as
a guide to assist with the future land use planning of properties within the study area and to
provide regulators with the details required to evaluate conformance with regulatory requirements
BAXTER CREEK FLOOD STUDY – Bozeman, MT
Introduction Page 1-2
Version 11/15/2023
governing future development. This report may also be used as an engineering guide for the
design of hydraulic structures, i.e. future bridges and/or culverts, within the study area.
1.2 Overview
Hyalite Engineers has completed a study of the 100-year flood on Baxter Creek from its junction
with Farmers Canal to Huffine Road approximately 4,400 feet to the south. The specific purpose
of the study is to present the results of detailed hydraulic model and to define the 100-year flood
elevations (or Base Flood Elevation (BFE) associated with a 1 percent chance flood event) and
floodplain boundaries within the study area.
This report presents areas of increased flood risk associated with Baxter Creek and the Farmer’s
Canal. Industry standard methods were utilized with flood flows obtained from USGS sources and
modeling from US Army Corps of Engineers HEC-RAS software. The results presented constitute
a reasonable conservative estimation of flood risk for the site.
BAXTER CREEK FLOOD STUDY – Bozeman, MT
Location and Site Information Page 2-1
Version 11/15/2023
2 Location and Site Information
2.1 Location
The study area is located in Gallatin County, Montana and encompasses approximately 70 acres
of Section 9, Township 25, Range 5E, P.M.M. This detailed study includes 100-year Base
Floodplain Elevations (BEF’s) and floodplain determination for approximately 4,000 feet of Baxter
Creek directly north of its junction with the Farmers Canal. Current land uses along this stretch of
Baxter Creek include medium density residential, light industrial, agricultural and pasture land.
The Federal Emergency Management Agency (FEMA) flood insurance rate maps indicate that
the study area is not a mapped floodway but rather an “Area of Minimal Flood Hazard.”
Figure 1 - Study area (project site) map.
2.2 Local Topography
The topography of the site and surrounding area is gently sloping (0 to 4 percent slopes)
residential, commercial and agricultural land. The site slopes to the north in conjunction with flow
direction of Baxter Creek. Both eastern and western side slopes of Baxter Creek are relatively
gradual. Dense shrubbery and wetlands occupy the majority of the area near the top of the banks.
Baxter Creek flows parallel to the west the study area flowing from the southeast to the northwest.
The photographs and maps attached hereto provide a representative view of the site topography.
BAXTER CREEK FLOOD STUDY – Bozeman, MT
Location and Site Information Page 2-2
Version 11/15/2023
2.3 Site Geology and Soil Conditions
Previous studies by others indicate that the Gallatin Valley is part of the Three Forks structural
basin that was formed as a result of crustal movements during early Tertiary time. The valley is
filled with tertiary sediments, coalescing alluvial fans, alluvium, and bedrock. The study area is
located in the central part of the Gallatin Valley, which is covered by Quaternary Alluvium
deposited primarily by Hyalite Creek (aka Middle Creek), and other smaller drainages flowing
north out of the Gallatin Range. As presented by others, the alluvium consists primarily of cobbles
and gravel intermixed with sand, silt, and clay.
A United States Department of Agriculture (USDA) Natural Resources Conservation Service
(NRCS) soils report was obtained for the study area. A copy of the report is attached in Appendix
F. Please refer to the attached soil report for additional information on site soils. In general, the
site soils are loams and cobbly loams overlying various stratum of gravelly loam, gravelly sandy
clay loam, and cobbly clay loam.
2.4 Regional Groundwater Conditions
Groundwater levels within the study area fluctuate seasonally. Four (4) monitoring wells on the
property located on the west side of Baxter Creek and north of Huffine Lane monitored by Hyalite
Engineers from May of 2021 to September of 2022. The monitoring indicated that the groundwater
levels throughout the site generally rise from spring to late summer and fall throughout the rest of
the year. Over the course of monitoring the groundwater, the depths varied from 1 foot deep to 5
feet.
BAXTER CREEK FLOOD STUDY – Bozeman, MT
Hydrologic Analysis Page 3-3
Version 11/15/2023
3 Hydrologic Analysis
3.1 General Hydrologic Information and Basin Description
Baxter Creek originates from the Farmers Canal south east of the area of study, and flows in a
north and northwest direction to its confluence with the East Gallatin River near Belgrade, MT.
Baxter Creek (from its origin at Farmers Canal to I-90 crossing) is a loosing stream during the
summer months from irrigation diversions and the gravelly porous nature of the native soils
beneath the creek bed. In this part of the valley there are numerous irrigation canals and ditches
which affect the drainage pattern of the creek and the resultant peak discharge. Information on
quantifying changes in the peak discharge due to irrigation and infiltration is limited so worst case
flows must be assumed.
Flood basins were determined from the existing and proposed topography of the area to be
analyzed. The Farmers Canal to the south was used as the southern boundary of the flood area,
and five total basins were delineated and analyzed (see Appendix B). It is assumed that the flows
from each basin will end up meeting at the Baxter Creek culvert crossing beneath Fallon Street.
Knowing this, peak flows for the flood area were analyzed at that culvert, as it is expected to
generate the highest peak flow rate from our drainage area.
3.2 Floodplain Characteristics
The floodplain surrounding the watercourse within the study area is generally quite flat and the
channel banks are level or slightly higher than the adjacent plain. The study area is generally
used as residential, commercial and pasture lots with some dense vegetation and shrubbery near
the top of the stream bank.
3.3 Determination of 100-year Flows
Due to the urban nature of the basin and its small size, it was determined that stormwater flow
quantification techniques would be more appropriate for determining flooding characteristics,
namely the SCS method. This method also allows for the estimation of time-resolved hydrographs
that can be used in unsteady flow modeling, which increases the accuracy of the results.
The Hydraflow Hydrographs Extension for Autodesk Civil 3D was used to calculate the peak
flows, and hydrographs for each basin. 24-hr precipitation data was analyzed from the NOAA
Atlas 2- Precipitation Frequency Atlas of the Western United States, Volume 1- Montana (1973).
Curve numbers were determined for each basin using existing and proposed site conditions, and
hydrologic soil group classifications were determined with the NRCS soil mapping program. Using
the basin area, precipitation data, and topographic characteristics- flow paths, time of
concentration, and peak flows were determined for each basin via the SCS method. With the peak
flows from each basin, an overall peak flow, and hydrograph, was estimated for the entire basin.
Since the 24-hr precipitation data was used, the Hydraflow program calculates and allows us to
view the overall peak flow hydrographs in the 2-yr, 10-yr, 25-yr, 50-yr, and 100-yr 24-hr storm
events. See Appendix C for the Hydraflow inputs and results for each basin during the analyzed
storm events.
BAXTER CREEK FLOOD STUDY – Bozeman, MT
Hydrologic Analysis Page 3-4
Version 11/15/2023
3.4 Flow Contribution from Up-Gradient Hydraulic Structures
Baxter Creek originates at a headgate off of Farmers Canal at the northern boundary of the Loyal
Gardens Subdivision. As a worst case, it is assumed that the Farmers Canal to Baxter Creek
headgate is fully open during the storm event that would generate the 100-year flow. When fully
open, the headgate can be approximated as a 36” culvert with a submerged inlet. HY-8 software
(by the US Federal Highway Administration) is well suited to estimate the flow from this structure.
The HY-8 analysis can be found in Appendix D. As a worst case, it was assumed that the Farmers
Canal would be completely full, and the headgate completely open. This condition correlates to
the overtopping flow reported in Appendix D of 50.85 CFS.
3.5 Total Flows Used in Hydraulic Modeling
The 100-year hydrograph determined as described in Section 3.3 were added to the assumed
constant 50.85 CFS worst case flow from the farmers canal to arrive at the final 100-year
hydrograph to be used in the hydraulic modeling. Figure 2 shows the 100-year hydrograph that
was modeled.
Figure 2 - Flow hydrograph used in the hydraulic analysis.
BAXTER CREEK FLOOD STUDY – Bozeman, MT
Hydraulic Analysis Page 4-5
Version 11/15/2023
4 Hydraulic Analysis
4.1 Hydraulic Analysis and Methodology
Flood flows through the study are were simulated with a 2D HEC-RAS model. 2D modeling, as
opposed to 1D, provides much greater detail as the result of the significant amount of data and
effort needed. The results of the 2D analysis were used to develop the Flood Study Model Maps
in Appendix A.
4.2 HEC RAS 2D Modeling Analysis & Assumptions
The 2D HEC-RAS model is calculated using a numerical approach that simulates the behavior of
water flow in two dimensions (both horizontally and vertically) across a terrain. The model solves
the full two-dimensional shallow flow equations to simulate the flow dynamics, including
momentum, energy, and continuity equations. The first step is to create a computational mesh
that divides the study area into a grid of interconnected cells. This mesh represents the study
area terrain and is used to discretize the governing equations. The model solves the 2D shallow
flow equations, which are partial differential equations, using numerical methods. This numerical
approach discretizes the equations into algebraic equations for each cell and iteratively solves
them for each time step. Once the simulation is complete, the results are analyzed and visualized
to understand the flow patterns, water depths, velocities, and areas of inundation.
The existing and proposed ground surfaces are taken from the project design files and converted
into HEC-RAS terrain data for modeling. Existing culverts were surveyed and added into the
model. The upstream boundary condition was input as a flow hydrograph as described in Section
3.5. Normal depth was used for the downstream boundary conditions. Manning’s N was
determined to be .04 for the floodplain and .03 for the water courses. Figure 3 and Figure 4 show
an overview of the model study area, terrain, structures, and boundary locations.
BAXTER CREEK FLOOD STUDY – Bozeman, MT
Hydraulic Analysis Page 4-6
Version 11/15/2023
Figure 3 - Overview of existing conditions model geometry. Flow boundaries IN and OUT noted.
Computational mesh does not cover areas where no flow is calculated.
Figure 4 - Overview of proposed conditions model geometry. Flow boundaries IN and OUT noted.
Computational mesh does not cover areas where no flow is calculated.
Huffine S. Ditch OUT Baxter IN
Baxter OUT
Huffine S. Ditch OUT Baxter IN
Baxter OUT
BAXTER CREEK FLOOD STUDY – Bozeman, MT
Hydraulic Analysis Page 4-7
Version 11/15/2023
Unsteady flow analysis of both the existing and proposed conditions were preformed using a
computation interval of 5 seconds and an output interval of 1 hour. The analysis was set to
diffusion wave for the most accurate results. The analysis shows a time-resolved estimate of how
the hydrograph (applied at the upstream boundary) moves through the study area. A map of the
maximum flood water depth experienced at each 2D cell is the primary result output result chosen
for this analysis, but other metrics can also be reported upon request.
4.3 Discussion of Results
The results of the existing conditions 2D model shows predicts shallow flooding within the study
area and overtopping of Huffine Ln. Existing culverts are predicted to be inundated and existing
roadways are impacted. Please see Appendix A for greater detail. Generally, flow to the study
area is predicted to be shallow sheet flow that is less than 0.5 feet in depth outside of the Baxter
Creek channel. Flow is predicted to be attenuated by Huffine Ln, and some excess flow is
predicted to flow to the west in the southern roadside ditch outside of the study area. Mitigation
of the shallow flooding will be required as discussed later within this section of the report.
Although not shown, it should be noted that a flood of this magnitude would have significant
impacts to existing residential and commercial development both upstream and downstream of
the study area.
Figure 5 - Existing condition results map showing maximum flood depths.
Huffine Ln.
Competition Dr.
Fallon St. S. Cottonwood Rd.
BAXTER CREEK FLOOD STUDY – Bozeman, MT
Hydraulic Analysis Page 4-8
Version 11/15/2023
Figure 6 - Proposed condition results map showing maximum flood depths.
The proposed conditions model is an exact copy of the existing conditions model, but with the
addition of proposed street geometries, proposed culverts, and preliminary lot grading. The
modifications that are proposed are predicted to mitigate the shallow flooding by directing it back
into the exiting Baxter Creek channel. Modifications to the Baxter Creek channel itself are also
modeled and include a new crossing at Competition Drive, and stream restoration work that is
intended to bring the stream channel back to a more natural alignment. The Competition Dr.
crossing is modeled to require a 10’ span by 4.5’ depth concrete box culvert (or equivalent) able
to convey 125 CFS. Modifications to the Stream bed itself do not significantly affect the flood
depths, but flooding should be considered in the final design, and the channel should be modified
to convey an equal or greater flow rate than exists now.
The most significant proposed hydraulic feature that will direct shallow flow back to the Baxter
Creek channel is the Huffine Ln Ditch as shown in Figure 6. The proposed Huffine Ln Ditch is on
the northern seif of the road, and will normally take stormwater that originates in the Loyal Garden
Subdivision and crosses Huffine via a 24” diameter culvert. During a flood event though, this ditch
and any culvert on the ditch will take floodwaters that overtop Huffine and direct the floodwaters
back to Baxter Creek, and away from the proposed development. The capacity of the ditch and
any associated culverts must be at least 30 CFS to convey the portion of the 100-year event that
is predicted to flow through this area at its peak.
Each of these structures discussed above have been included in the HEC-RAS 2D proposed
conditions model. Final design of these structures may differ relative to what is modeled, but
capacities should be matched or exceeded. No upsizing of existing structures is required.
Huffine Ln.
Competition Dr.
Fallon St. S. Cottonwood Rd. Huffine Ln. Ditch
BAXTER CREEK FLOOD STUDY – Bozeman, MT
Study Limitations Page 5-1
Version 11/15/2023
5 Study Limitations
The analysis prepared for this report utilizes several assumptions to simplify the evaluation and
reflect reasonable and conservative estimates for flooding water surface elevations throughout
the study area. The analysis presented herein represents a best current estimate of flooding water
surface elevations with the best available data and accepted industry standard techniques.
Ice damming and channel migration were not analyzed in detail but may pose flooding and
avulsion threats to the planned building sites. These anthropogenic structures include upstream
dams, culverts, and irrigation ditches. For example, the failure of the Farmers Canal was not
considered quantitatively.
BAXTER CREEK FLOOD STUDY – Bozeman, MT
References Page 5-2
Version 11/15/2023
References
Brunner, Gary W. 2016. “HEC-RAS River Analysis System Hydraulic Reference Manual Version
5.0.”
FEMA. 2009. “Appendix C: Guidence for Riverine Flooding Analysis and Mapping.” In
Guidelines and Specifications for Flood Hazard Mapping Partners.
Veseth, R., and C. Montagne. 1980. “Geologic Parent Materials of Montana Soils.”
Appendix A: Flood Mapping
481548204825
482048254830M:\203430\Drawings\PHASE 2\FLOOD HAZARD EVAL\FIGURE 1 EXTG FLOOD.dwg
0'200'400'600'HUFFINE LN.HUFFINE LN.S. COTTONWOOD RD.S. COTTONWOOD RD.
BAXTER CR.BAXTER CR.FALLON ST.W. BABCOCK ST.COMPETITION DR.LAUREL PKWY.LAUREL PKWY.
4
8
2
0
48254830M:\203430\Drawings\PHASE 2\FLOOD HAZARD EVAL\FIGURE 2 PROP FLOOD.dwg
0'200'400'600'HUFFINE LN.HUFFINE LN.S. COTTONWOOD RD.S. COTTONWOOD RD.
BAXTER CR.BAXTER CR.FALLON ST.W. BABCOCK ST.COMPETITION DR.LAUREL PKWY.LAUREL PKWY.
Appendix B: Basin Map
GASFO
8''W 8''W
S
S
S S
SSS
HYD
HYD
HYD
SS
S
8''WHYD
HYD
HYD
FO FO FO FOFOFOFOFO
FO
HYD>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>
>
>>>>>>>>>>>>>>>>>>>>>>>>>>M:\203430\Drawings\PHASE 2\FLOOD HAZARD EVAL\C-FLOOD BASINS.dwgFLOOD HAZARD BASIN FIGURE
EXHIBIT "A"
203430JOB NUMBER :
SHEET :
SCALE :AS NOTED
1 OF 10Feet500
DATE :10/25/2023URBAN + FARM MAJOR
SUBDIVISION
FLOOD HAZARD ANALYSISW E B : w w w . h y a l i t e e n g . c o m
2304 NORTH 7TH AVENUE STE. L B O Z E M A N , M T 5 9 7 1 8
P H O N E : ( 4 0 6) 5 8 7 - 2 7 8 1 F A X : ( 4 0 6 ) 5 2 2 - 9 2 2 5
HUFFINE LNBAXTER
CREEKBAXTER CREEKS. COTTONWOOD RDBASIN C
63.31 ACRES
BASIN D
51.20 ACRES
BASIN A
24.45 ACRES
BASIN B
22.36 ACRES FLOW PATH
FALLON ST
FARME
R
S
C
A
N
A
L
BASIN E
24.57 ACRES
Appendix C: Hydrology Calculations
1 2
3 45
6
1
Watershed Model Schematic Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2023
Project: Hydrograph.gpw Wednesday, 10 / 25 / 2023
Hyd.Origin Description
Legend
1 SCS Runoff Basin A
2 SCS Runoff Basin B
3 SCS Runoff BASIN C
4 SCS Runoff BASIN D
5 SCS Runoff BASIN E
6 Combine BAXTER CREEK CULVERT
BASIN A BASIN B
BASIN C BASIN D
BASIN E
Hydrograph Return Period Recap
2
Hyd. Hydrograph Inflow Peak Outflow (cfs)Hydrograph
No. type hyd(s)Description
(origin) 1-yr 2-yr 3-yr 5-yr 10-yr 25-yr 50-yr 100-yr
1 SCS Runoff ------ ------- 15.92 ------- ------- 35.64 47.08 56.27 62.75 Basin A
2 SCS Runoff ------ ------- 18.97 ------- ------- 36.25 45.72 53.20 58.41 Basin B
3 SCS Runoff ------ ------- 12.69 ------- ------- 43.97 63.94 80.89 93.21 BASIN C
4 SCS Runoff ------ ------- 14.03 ------- ------- 29.59 38.41 45.45 50.41 BASIN D
5 SCS Runoff ------ ------- 23.84 ------- ------- 45.49 57.35 66.71 73.25 BASIN E
6 Combine 1, 2, 3,
4, 5
------- 73.91 ------- ------- 168.31 223.89 268.96 300.95 BAXTER CREEK CULVERT
Proj. file: Hydrograph.gpw Wednesday, 10 / 25 / 2023
Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2023
Hydrograph Summary Report
3
Hyd. Hydrograph Peak Time Time to Hyd. Inflow Maximum Total Hydrograph
No. type flow interval Peak volume hyd(s) elevation strge used Description
(origin) (cfs) (min) (min) (cuft) (ft) (cuft)
1 SCS Runoff 15.92 2 722 41,890 ------ ------ ------ Basin A
2 SCS Runoff 18.97 2 722 53,197 ------ ------ ------ Basin B
3 SCS Runoff 12.69 2 726 50,570 ------ ------ ------ BASIN C
4 SCS Runoff 14.03 2 756 103,226 ------ ------ ------ BASIN D
5 SCS Runoff 23.84 2 720 61,828 ------ ------ ------ BASIN E
6 Combine 73.91 2 722 310,711 1, 2, 3,
4, 5
------ ------ BAXTER CREEK CULVERT
Hydrograph.gpw Return Period: 2 Year Wednesday, 10 / 25 / 2023
Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2023
Hydrograph Report
Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2023 Wednesday, 10 / 25 / 2023
Hyd. No. 1
Basin A
Hydrograph type = SCS Runoff Peak discharge = 15.92 cfs
Storm frequency = 2 yrs Time to peak = 12.03 hrs
Time interval = 2 min Hyd. volume = 41,890 cuft
Drainage area = 24.450 ac Curve number = 90*
Basin Slope = 0.0 % Hydraulic length = 0 ft
Tc method = TR55 Time of conc. (Tc) = 13.20 min
Total precip. = 1.20 in Distribution = Type II
Storm duration = 24 hrs Shape factor = 484
* Composite (Area/CN) = [(5.000 x 74) + (19.450 x 94)] / 24.450
4
0 2 4 6 8 10 12 14 16 18 20 22 24 26
Q (cfs)
0.00 0.00
3.00 3.00
6.00 6.00
9.00 9.00
12.00 12.00
15.00 15.00
18.00 18.00
Q (cfs)
Time (hrs)
Basin A
Hyd. No. 1 -- 2 Year
Hyd No. 1
TR55 Tc Worksheet
5
Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2023
Hyd. No. 1
Basin A
Description A B C Totals
Sheet Flow
Manning's n-value = 0.016 0.000 0.000
Flow length (ft) = 65.0 0.0 0.0
Two-year 24-hr precip. (in) = 1.13 0.00 0.00
Land slope (%) = 1.10 0.00 0.00
Travel Time (min) = 2.48 + 0.00 + 0.00 = 2.48
Shallow Concentrated Flow
Flow length (ft) = 420.80 70.00 0.00
Watercourse slope (%) = 2.00 0.03 0.00
Surface description = Paved Unpaved Paved
Average velocity (ft/s) =2.87 0.28 0.00
Travel Time (min) = 2.44 + 4.17 + 0.00 = 6.61
Channel Flow
X sectional flow area (sqft) = 1.77 3.14 1.77
Wetted perimeter (ft) = 2.36 3.14 2.36
Channel slope (%) = 1.70 1.00 0.10
Manning's n-value = 0.013 0.013 0.013
Velocity (ft/s) =12.32
11.46
2.99
Flow length (ft) ({0})202.7 418.8 576.8
Travel Time (min) = 0.27 + 0.61 + 3.22 = 4.10
Total Travel Time, Tc .............................................................................. 13.20 min
Hydrograph Report
Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2023 Wednesday, 10 / 25 / 2023
Hyd. No. 2
Basin B
Hydrograph type = SCS Runoff Peak discharge = 18.97 cfs
Storm frequency = 2 yrs Time to peak = 12.03 hrs
Time interval = 2 min Hyd. volume = 53,197 cuft
Drainage area = 22.360 ac Curve number = 94
Basin Slope = 0.0 % Hydraulic length = 0 ft
Tc method = TR55 Time of conc. (Tc) = 16.00 min
Total precip. = 1.20 in Distribution = Type II
Storm duration = 24 hrs Shape factor = 484
6
0 2 4 6 8 10 12 14 16 18 20 22 24 26
Q (cfs)
0.00 0.00
3.00 3.00
6.00 6.00
9.00 9.00
12.00 12.00
15.00 15.00
18.00 18.00
21.00 21.00
Q (cfs)
Time (hrs)
Basin B
Hyd. No. 2 -- 2 Year
Hyd No. 2
TR55 Tc Worksheet
7
Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2023
Hyd. No. 2
Basin B
Description A B C Totals
Sheet Flow
Manning's n-value = 0.011 0.011 0.011
Flow length (ft) = 85.5 0.0 0.0
Two-year 24-hr precip. (in) = 1.13 0.00 0.00
Land slope (%) = 2.00 0.00 0.00
Travel Time (min) = 1.80 + 0.00 + 0.00 = 1.80
Shallow Concentrated Flow
Flow length (ft) = 1459.00 0.00 0.00
Watercourse slope (%) = 1.00 0.00 0.00
Surface description = Paved Paved Paved
Average velocity (ft/s) =2.03 0.00 0.00
Travel Time (min) = 11.96 + 0.00 + 0.00 = 11.96
Channel Flow
X sectional flow area (sqft) = 1.77 0.00 0.00
Wetted perimeter (ft) = 2.36 0.00 0.00
Channel slope (%) = 0.20 0.00 0.00
Manning's n-value = 0.013 0.015 0.015
Velocity (ft/s) =4.23
0.00
0.00
Flow length (ft) ({0})570.5 0.0 0.0
Travel Time (min) = 2.25 + 0.00 + 0.00 = 2.25
Total Travel Time, Tc .............................................................................. 16.00 min
Hydrograph Report
Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2023 Wednesday, 10 / 25 / 2023
Hyd. No. 3
BASIN C
Hydrograph type = SCS Runoff Peak discharge = 12.69 cfs
Storm frequency = 2 yrs Time to peak = 12.10 hrs
Time interval = 2 min Hyd. volume = 50,570 cuft
Drainage area = 63.310 ac Curve number = 83
Basin Slope = 0.0 % Hydraulic length = 0 ft
Tc method = TR55 Time of conc. (Tc) = 16.90 min
Total precip. = 1.20 in Distribution = Type II
Storm duration = 24 hrs Shape factor = 484
8
0 2 4 6 8 10 12 14 16 18 20 22 24 26
Q (cfs)
0.00 0.00
2.00 2.00
4.00 4.00
6.00 6.00
8.00 8.00
10.00 10.00
12.00 12.00
14.00 14.00
Q (cfs)
Time (hrs)
BASIN C
Hyd. No. 3 -- 2 Year
Hyd No. 3
TR55 Tc Worksheet
9
Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2023
Hyd. No. 3
BASIN C
Description A B C Totals
Sheet Flow
Manning's n-value = 0.011 0.011 0.011
Flow length (ft) = 169.5 27.0 0.0
Two-year 24-hr precip. (in) = 1.13 1.13 0.00
Land slope (%) = 1.60 1.50 0.00
Travel Time (min) = 3.40 + 0.80 + 0.00 = 4.20
Shallow Concentrated Flow
Flow length (ft) = 662.75 0.00 0.00
Watercourse slope (%) = 0.50 0.00 0.00
Surface description = Paved Paved Paved
Average velocity (ft/s) =1.44 0.00 0.00
Travel Time (min) = 7.68 + 0.00 + 0.00 = 7.68
Channel Flow
X sectional flow area (sqft) = 1.23 12.00 0.00
Wetted perimeter (ft) = 1.96 6.00 0.00
Channel slope (%) = 1.00 1.60 0.00
Manning's n-value = 0.015 0.026 0.000
Velocity (ft/s) =7.27
11.53
0.00
Flow length (ft) ({0})346.7 2902.0 0.0
Travel Time (min) = 0.79 + 4.19 + 0.00 = 4.99
Total Travel Time, Tc .............................................................................. 16.90 min
Hydrograph Report
Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2023 Wednesday, 10 / 25 / 2023
Hyd. No. 4
BASIN D
Hydrograph type = SCS Runoff Peak discharge = 14.03 cfs
Storm frequency = 2 yrs Time to peak = 12.60 hrs
Time interval = 2 min Hyd. volume = 103,226 cuft
Drainage area = 51.200 ac Curve number = 92
Basin Slope = 0.0 % Hydraulic length = 0 ft
Tc method = TR55 Time of conc. (Tc) = 68.30 min
Total precip. = 1.20 in Distribution = Type II
Storm duration = 24 hrs Shape factor = 484
10
0 2 4 6 8 10 12 14 16 18 20 22 24 26
Q (cfs)
0.00 0.00
3.00 3.00
6.00 6.00
9.00 9.00
12.00 12.00
15.00 15.00
Q (cfs)
Time (hrs)
BASIN D
Hyd. No. 4 -- 2 Year
Hyd No. 4
TR55 Tc Worksheet
11
Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2023
Hyd. No. 4
BASIN D
Description A B C Totals
Sheet Flow
Manning's n-value = 0.150 0.011 0.011
Flow length (ft) = 300.0 0.0 0.0
Two-year 24-hr precip. (in) = 1.13 0.00 0.00
Land slope (%) = 1.60 0.00 0.00
Travel Time (min) = 43.41 + 0.00 + 0.00 = 43.41
Shallow Concentrated Flow
Flow length (ft) = 2779.00 0.00 0.00
Watercourse slope (%) = 1.60 0.00 0.00
Surface description = Unpaved Paved Paved
Average velocity (ft/s) =2.04 0.00 0.00
Travel Time (min) = 22.69 + 0.00 + 0.00 = 22.69
Channel Flow
X sectional flow area (sqft) = 12.00 0.00 0.00
Wetted perimeter (ft) = 6.00 0.00 0.00
Channel slope (%) = 1.60 0.00 0.00
Manning's n-value = 0.026 0.015 0.015
Velocity (ft/s) =11.53
0.00
0.00
Flow length (ft) ({0})1498.7 0.0 0.0
Travel Time (min) = 2.17 + 0.00 + 0.00 = 2.17
Total Travel Time, Tc .............................................................................. 68.30 min
Hydrograph Report
Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2023 Wednesday, 10 / 25 / 2023
Hyd. No. 5
BASIN E
Hydrograph type = SCS Runoff Peak discharge = 23.84 cfs
Storm frequency = 2 yrs Time to peak = 12.00 hrs
Time interval = 2 min Hyd. volume = 61,828 cuft
Drainage area = 24.570 ac Curve number = 94
Basin Slope = 0.0 % Hydraulic length = 0 ft
Tc method = TR55 Time of conc. (Tc) = 12.40 min
Total precip. = 1.20 in Distribution = Type II
Storm duration = 24 hrs Shape factor = 484
12
0 2 4 6 8 10 12 14 16 18 20 22 24 26
Q (cfs)
0.00 0.00
4.00 4.00
8.00 8.00
12.00 12.00
16.00 16.00
20.00 20.00
24.00 24.00
Q (cfs)
Time (hrs)
BASIN E
Hyd. No. 5 -- 2 Year
Hyd No. 5
TR55 Tc Worksheet
13
Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2023
Hyd. No. 5
BASIN E
Description A B C Totals
Sheet Flow
Manning's n-value = 0.011 0.011 0.011
Flow length (ft) = 30.0 0.0 0.0
Two-year 24-hr precip. (in) = 1.20 0.00 0.00
Land slope (%) = 2.00 0.00 0.00
Travel Time (min) = 0.76 + 0.00 + 0.00 = 0.76
Shallow Concentrated Flow
Flow length (ft) = 416.00 28.00 0.00
Watercourse slope (%) = 0.50 1.00 0.00
Surface description = Paved Paved Paved
Average velocity (ft/s) =1.44 2.03 0.00
Travel Time (min) = 4.82 + 0.23 + 0.00 = 5.05
Channel Flow
X sectional flow area (sqft) = 1.23 4.91 12.00
Wetted perimeter (ft) = 1.96 7.85 6.00
Channel slope (%) = 1.00 1.00 1.60
Manning's n-value = 0.010 0.013 0.026
Velocity (ft/s) =10.90
8.37
11.53
Flow length (ft) ({0})1357.0 167.0 2909.0
Travel Time (min) = 2.07 + 0.33 + 4.20 = 6.61
Total Travel Time, Tc .............................................................................. 12.40 min
Hydrograph Report
Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2023 Wednesday, 10 / 25 / 2023
Hyd. No. 6
BAXTER CREEK CULVERT
Hydrograph type = Combine Peak discharge = 73.91 cfs
Storm frequency = 2 yrs Time to peak = 12.03 hrs
Time interval = 2 min Hyd. volume = 310,711 cuft
Inflow hyds. = 1, 2, 3, 4, 5 Contrib. drain. area = 185.890 ac
14
0 2 4 6 8 10 12 14 16 18 20 22 24 26
Q (cfs)
0.00 0.00
10.00 10.00
20.00 20.00
30.00 30.00
40.00 40.00
50.00 50.00
60.00 60.00
70.00 70.00
80.00 80.00
Q (cfs)
Time (hrs)
BAXTER CREEK CULVERT
Hyd. No. 6 -- 2 Year
Hyd No. 6 Hyd No. 1 Hyd No. 2 Hyd No. 3
Hyd No. 4 Hyd No. 5
Hydrograph Summary Report
15
Hyd. Hydrograph Peak Time Time to Hyd. Inflow Maximum Total Hydrograph
No. type flow interval Peak volume hyd(s) elevation strge used Description
(origin) (cfs) (min) (min) (cuft) (ft) (cuft)
1 SCS Runoff 35.64 2 720 92,382 ------ ------ ------ Basin A
2 SCS Runoff 36.25 2 722 103,121 ------ ------ ------ Basin B
3 SCS Runoff 43.97 2 726 144,257 ------ ------ ------ BASIN C
4 SCS Runoff 29.59 2 756 213,332 ------ ------ ------ BASIN D
5 SCS Runoff 45.49 2 720 119,850 ------ ------ ------ BASIN E
6 Combine 168.31 2 722 672,941 1, 2, 3,
4, 5
------ ------ BAXTER CREEK CULVERT
Hydrograph.gpw Return Period: 10 Year Wednesday, 10 / 25 / 2023
Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2023
Hydrograph Report
Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2023 Wednesday, 10 / 25 / 2023
Hyd. No. 1
Basin A
Hydrograph type = SCS Runoff Peak discharge = 35.64 cfs
Storm frequency = 10 yrs Time to peak = 12.00 hrs
Time interval = 2 min Hyd. volume = 92,382 cuft
Drainage area = 24.450 ac Curve number = 90*
Basin Slope = 0.0 % Hydraulic length = 0 ft
Tc method = TR55 Time of conc. (Tc) = 13.20 min
Total precip. = 1.90 in Distribution = Type II
Storm duration = 24 hrs Shape factor = 484
* Composite (Area/CN) = [(5.000 x 74) + (19.450 x 94)] / 24.450
16
0 2 4 6 8 10 12 14 16 18 20 22 24 26
Q (cfs)
0.00 0.00
10.00 10.00
20.00 20.00
30.00 30.00
40.00 40.00
Q (cfs)
Time (hrs)
Basin A
Hyd. No. 1 -- 10 Year
Hyd No. 1
Hydrograph Report
Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2023 Wednesday, 10 / 25 / 2023
Hyd. No. 2
Basin B
Hydrograph type = SCS Runoff Peak discharge = 36.25 cfs
Storm frequency = 10 yrs Time to peak = 12.03 hrs
Time interval = 2 min Hyd. volume = 103,121 cuft
Drainage area = 22.360 ac Curve number = 94
Basin Slope = 0.0 % Hydraulic length = 0 ft
Tc method = TR55 Time of conc. (Tc) = 16.00 min
Total precip. = 1.90 in Distribution = Type II
Storm duration = 24 hrs Shape factor = 484
17
0 2 4 6 8 10 12 14 16 18 20 22 24 26
Q (cfs)
0.00 0.00
10.00 10.00
20.00 20.00
30.00 30.00
40.00 40.00
Q (cfs)
Time (hrs)
Basin B
Hyd. No. 2 -- 10 Year
Hyd No. 2
Hydrograph Report
Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2023 Wednesday, 10 / 25 / 2023
Hyd. No. 3
BASIN C
Hydrograph type = SCS Runoff Peak discharge = 43.97 cfs
Storm frequency = 10 yrs Time to peak = 12.10 hrs
Time interval = 2 min Hyd. volume = 144,257 cuft
Drainage area = 63.310 ac Curve number = 83
Basin Slope = 0.0 % Hydraulic length = 0 ft
Tc method = TR55 Time of conc. (Tc) = 16.90 min
Total precip. = 1.90 in Distribution = Type II
Storm duration = 24 hrs Shape factor = 484
18
0 2 4 6 8 10 12 14 16 18 20 22 24 26
Q (cfs)
0.00 0.00
10.00 10.00
20.00 20.00
30.00 30.00
40.00 40.00
50.00 50.00
Q (cfs)
Time (hrs)
BASIN C
Hyd. No. 3 -- 10 Year
Hyd No. 3
Hydrograph Report
Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2023 Wednesday, 10 / 25 / 2023
Hyd. No. 4
BASIN D
Hydrograph type = SCS Runoff Peak discharge = 29.59 cfs
Storm frequency = 10 yrs Time to peak = 12.60 hrs
Time interval = 2 min Hyd. volume = 213,332 cuft
Drainage area = 51.200 ac Curve number = 92
Basin Slope = 0.0 % Hydraulic length = 0 ft
Tc method = TR55 Time of conc. (Tc) = 68.30 min
Total precip. = 1.90 in Distribution = Type II
Storm duration = 24 hrs Shape factor = 484
19
0 2 4 6 8 10 12 14 16 18 20 22 24 26
Q (cfs)
0.00 0.00
5.00 5.00
10.00 10.00
15.00 15.00
20.00 20.00
25.00 25.00
30.00 30.00
Q (cfs)
Time (hrs)
BASIN D
Hyd. No. 4 -- 10 Year
Hyd No. 4
Hydrograph Report
Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2023 Wednesday, 10 / 25 / 2023
Hyd. No. 5
BASIN E
Hydrograph type = SCS Runoff Peak discharge = 45.49 cfs
Storm frequency = 10 yrs Time to peak = 12.00 hrs
Time interval = 2 min Hyd. volume = 119,850 cuft
Drainage area = 24.570 ac Curve number = 94
Basin Slope = 0.0 % Hydraulic length = 0 ft
Tc method = TR55 Time of conc. (Tc) = 12.40 min
Total precip. = 1.90 in Distribution = Type II
Storm duration = 24 hrs Shape factor = 484
20
0 2 4 6 8 10 12 14 16 18 20 22 24 26
Q (cfs)
0.00 0.00
10.00 10.00
20.00 20.00
30.00 30.00
40.00 40.00
50.00 50.00
Q (cfs)
Time (hrs)
BASIN E
Hyd. No. 5 -- 10 Year
Hyd No. 5
Hydrograph Report
Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2023 Wednesday, 10 / 25 / 2023
Hyd. No. 6
BAXTER CREEK CULVERT
Hydrograph type = Combine Peak discharge = 168.31 cfs
Storm frequency = 10 yrs Time to peak = 12.03 hrs
Time interval = 2 min Hyd. volume = 672,941 cuft
Inflow hyds. = 1, 2, 3, 4, 5 Contrib. drain. area = 185.890 ac
21
0 2 4 6 8 10 12 14 16 18 20 22 24 26
Q (cfs)
0.00 0.00
20.00 20.00
40.00 40.00
60.00 60.00
80.00 80.00
100.00 100.00
120.00 120.00
140.00 140.00
160.00 160.00
180.00 180.00
Q (cfs)
Time (hrs)
BAXTER CREEK CULVERT
Hyd. No. 6 -- 10 Year
Hyd No. 6 Hyd No. 1 Hyd No. 2 Hyd No. 3
Hyd No. 4 Hyd No. 5
Hydrograph Summary Report
22
Hyd. Hydrograph Peak Time Time to Hyd. Inflow Maximum Total Hydrograph
No. type flow interval Peak volume hyd(s) elevation strge used Description
(origin) (cfs) (min) (min) (cuft) (ft) (cuft)
1 SCS Runoff 47.08 2 720 122,304 ------ ------ ------ Basin A
2 SCS Runoff 45.72 2 722 131,371 ------ ------ ------ Basin B
3 SCS Runoff 63.94 2 726 205,165 ------ ------ ------ BASIN C
4 SCS Runoff 38.41 2 756 277,043 ------ ------ ------ BASIN D
5 SCS Runoff 57.35 2 720 152,684 ------ ------ ------ BASIN E
6 Combine 223.89 2 722 888,568 1, 2, 3,
4, 5
------ ------ BAXTER CREEK CULVERT
Hydrograph.gpw Return Period: 25 Year Wednesday, 10 / 25 / 2023
Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2023
Hydrograph Report
Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2023 Wednesday, 10 / 25 / 2023
Hyd. No. 1
Basin A
Hydrograph type = SCS Runoff Peak discharge = 47.08 cfs
Storm frequency = 25 yrs Time to peak = 12.00 hrs
Time interval = 2 min Hyd. volume = 122,304 cuft
Drainage area = 24.450 ac Curve number = 90*
Basin Slope = 0.0 % Hydraulic length = 0 ft
Tc method = TR55 Time of conc. (Tc) = 13.20 min
Total precip. = 2.28 in Distribution = Type II
Storm duration = 24 hrs Shape factor = 484
* Composite (Area/CN) = [(5.000 x 74) + (19.450 x 94)] / 24.450
23
0 2 4 6 8 10 12 14 16 18 20 22 24 26
Q (cfs)
0.00 0.00
10.00 10.00
20.00 20.00
30.00 30.00
40.00 40.00
50.00 50.00
Q (cfs)
Time (hrs)
Basin A
Hyd. No. 1 -- 25 Year
Hyd No. 1
Hydrograph Report
Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2023 Wednesday, 10 / 25 / 2023
Hyd. No. 2
Basin B
Hydrograph type = SCS Runoff Peak discharge = 45.72 cfs
Storm frequency = 25 yrs Time to peak = 12.03 hrs
Time interval = 2 min Hyd. volume = 131,371 cuft
Drainage area = 22.360 ac Curve number = 94
Basin Slope = 0.0 % Hydraulic length = 0 ft
Tc method = TR55 Time of conc. (Tc) = 16.00 min
Total precip. = 2.28 in Distribution = Type II
Storm duration = 24 hrs Shape factor = 484
24
0 2 4 6 8 10 12 14 16 18 20 22 24 26
Q (cfs)
0.00 0.00
10.00 10.00
20.00 20.00
30.00 30.00
40.00 40.00
50.00 50.00
Q (cfs)
Time (hrs)
Basin B
Hyd. No. 2 -- 25 Year
Hyd No. 2
Hydrograph Report
Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2023 Wednesday, 10 / 25 / 2023
Hyd. No. 3
BASIN C
Hydrograph type = SCS Runoff Peak discharge = 63.94 cfs
Storm frequency = 25 yrs Time to peak = 12.10 hrs
Time interval = 2 min Hyd. volume = 205,165 cuft
Drainage area = 63.310 ac Curve number = 83
Basin Slope = 0.0 % Hydraulic length = 0 ft
Tc method = TR55 Time of conc. (Tc) = 16.90 min
Total precip. = 2.28 in Distribution = Type II
Storm duration = 24 hrs Shape factor = 484
25
0 2 4 6 8 10 12 14 16 18 20 22 24 26
Q (cfs)
0.00 0.00
10.00 10.00
20.00 20.00
30.00 30.00
40.00 40.00
50.00 50.00
60.00 60.00
70.00 70.00
Q (cfs)
Time (hrs)
BASIN C
Hyd. No. 3 -- 25 Year
Hyd No. 3
Hydrograph Report
Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2023 Wednesday, 10 / 25 / 2023
Hyd. No. 4
BASIN D
Hydrograph type = SCS Runoff Peak discharge = 38.41 cfs
Storm frequency = 25 yrs Time to peak = 12.60 hrs
Time interval = 2 min Hyd. volume = 277,043 cuft
Drainage area = 51.200 ac Curve number = 92
Basin Slope = 0.0 % Hydraulic length = 0 ft
Tc method = TR55 Time of conc. (Tc) = 68.30 min
Total precip. = 2.28 in Distribution = Type II
Storm duration = 24 hrs Shape factor = 484
26
0 2 4 6 8 10 12 14 16 18 20 22 24 26
Q (cfs)
0.00 0.00
10.00 10.00
20.00 20.00
30.00 30.00
40.00 40.00
Q (cfs)
Time (hrs)
BASIN D
Hyd. No. 4 -- 25 Year
Hyd No. 4
Hydrograph Report
Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2023 Wednesday, 10 / 25 / 2023
Hyd. No. 5
BASIN E
Hydrograph type = SCS Runoff Peak discharge = 57.35 cfs
Storm frequency = 25 yrs Time to peak = 12.00 hrs
Time interval = 2 min Hyd. volume = 152,684 cuft
Drainage area = 24.570 ac Curve number = 94
Basin Slope = 0.0 % Hydraulic length = 0 ft
Tc method = TR55 Time of conc. (Tc) = 12.40 min
Total precip. = 2.28 in Distribution = Type II
Storm duration = 24 hrs Shape factor = 484
27
0 2 4 6 8 10 12 14 16 18 20 22 24 26
Q (cfs)
0.00 0.00
10.00 10.00
20.00 20.00
30.00 30.00
40.00 40.00
50.00 50.00
60.00 60.00
Q (cfs)
Time (hrs)
BASIN E
Hyd. No. 5 -- 25 Year
Hyd No. 5
Hydrograph Report
Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2023 Wednesday, 10 / 25 / 2023
Hyd. No. 6
BAXTER CREEK CULVERT
Hydrograph type = Combine Peak discharge = 223.89 cfs
Storm frequency = 25 yrs Time to peak = 12.03 hrs
Time interval = 2 min Hyd. volume = 888,568 cuft
Inflow hyds. = 1, 2, 3, 4, 5 Contrib. drain. area = 185.890 ac
28
0 2 4 6 8 10 12 14 16 18 20 22 24 26
Q (cfs)
0.00 0.00
30.00 30.00
60.00 60.00
90.00 90.00
120.00 120.00
150.00 150.00
180.00 180.00
210.00 210.00
240.00 240.00
Q (cfs)
Time (hrs)
BAXTER CREEK CULVERT
Hyd. No. 6 -- 25 Year
Hyd No. 6 Hyd No. 1 Hyd No. 2 Hyd No. 3
Hyd No. 4 Hyd No. 5
Hydrograph Summary Report
29
Hyd. Hydrograph Peak Time Time to Hyd. Inflow Maximum Total Hydrograph
No. type flow interval Peak volume hyd(s) elevation strge used Description
(origin) (cfs) (min) (min) (cuft) (ft) (cuft)
1 SCS Runoff 56.27 2 720 146,678 ------ ------ ------ Basin A
2 SCS Runoff 53.20 2 722 153,991 ------ ------ ------ Basin B
3 SCS Runoff 80.89 2 724 256,614 ------ ------ ------ BASIN C
4 SCS Runoff 45.45 2 756 328,475 ------ ------ ------ BASIN D
5 SCS Runoff 66.71 2 720 178,974 ------ ------ ------ BASIN E
6 Combine 268.96 2 722 1,064,731 1, 2, 3,
4, 5
------ ------ BAXTER CREEK CULVERT
Hydrograph.gpw Return Period: 50 Year Wednesday, 10 / 25 / 2023
Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2023
Hydrograph Report
Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2023 Wednesday, 10 / 25 / 2023
Hyd. No. 1
Basin A
Hydrograph type = SCS Runoff Peak discharge = 56.27 cfs
Storm frequency = 50 yrs Time to peak = 12.00 hrs
Time interval = 2 min Hyd. volume = 146,678 cuft
Drainage area = 24.450 ac Curve number = 90*
Basin Slope = 0.0 % Hydraulic length = 0 ft
Tc method = TR55 Time of conc. (Tc) = 13.20 min
Total precip. = 2.58 in Distribution = Type II
Storm duration = 24 hrs Shape factor = 484
* Composite (Area/CN) = [(5.000 x 74) + (19.450 x 94)] / 24.450
30
0 2 4 6 8 10 12 14 16 18 20 22 24 26
Q (cfs)
0.00 0.00
10.00 10.00
20.00 20.00
30.00 30.00
40.00 40.00
50.00 50.00
60.00 60.00
Q (cfs)
Time (hrs)
Basin A
Hyd. No. 1 -- 50 Year
Hyd No. 1
Hydrograph Report
Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2023 Wednesday, 10 / 25 / 2023
Hyd. No. 2
Basin B
Hydrograph type = SCS Runoff Peak discharge = 53.20 cfs
Storm frequency = 50 yrs Time to peak = 12.03 hrs
Time interval = 2 min Hyd. volume = 153,991 cuft
Drainage area = 22.360 ac Curve number = 94
Basin Slope = 0.0 % Hydraulic length = 0 ft
Tc method = TR55 Time of conc. (Tc) = 16.00 min
Total precip. = 2.58 in Distribution = Type II
Storm duration = 24 hrs Shape factor = 484
31
0 2 4 6 8 10 12 14 16 18 20 22 24 26
Q (cfs)
0.00 0.00
10.00 10.00
20.00 20.00
30.00 30.00
40.00 40.00
50.00 50.00
60.00 60.00
Q (cfs)
Time (hrs)
Basin B
Hyd. No. 2 -- 50 Year
Hyd No. 2
Hydrograph Report
Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2023 Wednesday, 10 / 25 / 2023
Hyd. No. 3
BASIN C
Hydrograph type = SCS Runoff Peak discharge = 80.89 cfs
Storm frequency = 50 yrs Time to peak = 12.07 hrs
Time interval = 2 min Hyd. volume = 256,614 cuft
Drainage area = 63.310 ac Curve number = 83
Basin Slope = 0.0 % Hydraulic length = 0 ft
Tc method = TR55 Time of conc. (Tc) = 16.90 min
Total precip. = 2.58 in Distribution = Type II
Storm duration = 24 hrs Shape factor = 484
32
0 2 4 6 8 10 12 14 16 18 20 22 24 26
Q (cfs)
0.00 0.00
10.00 10.00
20.00 20.00
30.00 30.00
40.00 40.00
50.00 50.00
60.00 60.00
70.00 70.00
80.00 80.00
90.00 90.00
Q (cfs)
Time (hrs)
BASIN C
Hyd. No. 3 -- 50 Year
Hyd No. 3
Hydrograph Report
Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2023 Wednesday, 10 / 25 / 2023
Hyd. No. 4
BASIN D
Hydrograph type = SCS Runoff Peak discharge = 45.45 cfs
Storm frequency = 50 yrs Time to peak = 12.60 hrs
Time interval = 2 min Hyd. volume = 328,475 cuft
Drainage area = 51.200 ac Curve number = 92
Basin Slope = 0.0 % Hydraulic length = 0 ft
Tc method = TR55 Time of conc. (Tc) = 68.30 min
Total precip. = 2.58 in Distribution = Type II
Storm duration = 24 hrs Shape factor = 484
33
0 2 4 6 8 10 12 14 16 18 20 22 24 26
Q (cfs)
0.00 0.00
10.00 10.00
20.00 20.00
30.00 30.00
40.00 40.00
50.00 50.00
Q (cfs)
Time (hrs)
BASIN D
Hyd. No. 4 -- 50 Year
Hyd No. 4
Hydrograph Report
Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2023 Wednesday, 10 / 25 / 2023
Hyd. No. 5
BASIN E
Hydrograph type = SCS Runoff Peak discharge = 66.71 cfs
Storm frequency = 50 yrs Time to peak = 12.00 hrs
Time interval = 2 min Hyd. volume = 178,974 cuft
Drainage area = 24.570 ac Curve number = 94
Basin Slope = 0.0 % Hydraulic length = 0 ft
Tc method = TR55 Time of conc. (Tc) = 12.40 min
Total precip. = 2.58 in Distribution = Type II
Storm duration = 24 hrs Shape factor = 484
34
0 2 4 6 8 10 12 14 16 18 20 22 24 26
Q (cfs)
0.00 0.00
10.00 10.00
20.00 20.00
30.00 30.00
40.00 40.00
50.00 50.00
60.00 60.00
70.00 70.00
Q (cfs)
Time (hrs)
BASIN E
Hyd. No. 5 -- 50 Year
Hyd No. 5
Hydrograph Report
Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2023 Wednesday, 10 / 25 / 2023
Hyd. No. 6
BAXTER CREEK CULVERT
Hydrograph type = Combine Peak discharge = 268.96 cfs
Storm frequency = 50 yrs Time to peak = 12.03 hrs
Time interval = 2 min Hyd. volume = 1,064,731 cuft
Inflow hyds. = 1, 2, 3, 4, 5 Contrib. drain. area = 185.890 ac
35
0 2 4 6 8 10 12 14 16 18 20 22 24 26
Q (cfs)
0.00 0.00
40.00 40.00
80.00 80.00
120.00 120.00
160.00 160.00
200.00 200.00
240.00 240.00
280.00 280.00
Q (cfs)
Time (hrs)
BAXTER CREEK CULVERT
Hyd. No. 6 -- 50 Year
Hyd No. 6 Hyd No. 1 Hyd No. 2 Hyd No. 3
Hyd No. 4 Hyd No. 5
Hydrograph Summary Report
36
Hyd. Hydrograph Peak Time Time to Hyd. Inflow Maximum Total Hydrograph
No. type flow interval Peak volume hyd(s) elevation strge used Description
(origin) (cfs) (min) (min) (cuft) (ft) (cuft)
1 SCS Runoff 62.75 2 720 164,039 ------ ------ ------ Basin A
2 SCS Runoff 58.41 2 722 169,946 ------ ------ ------ Basin B
3 SCS Runoff 93.21 2 724 294,037 ------ ------ ------ BASIN C
4 SCS Runoff 50.41 2 754 364,919 ------ ------ ------ BASIN D
5 SCS Runoff 73.25 2 720 197,517 ------ ------ ------ BASIN E
6 Combine 300.95 2 722 1,190,461 1, 2, 3,
4, 5
------ ------ BAXTER CREEK CULVERT
Hydrograph.gpw Return Period: 100 Year Wednesday, 10 / 25 / 2023
Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2023
Hydrograph Report
Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2023 Wednesday, 10 / 25 / 2023
Hyd. No. 1
Basin A
Hydrograph type = SCS Runoff Peak discharge = 62.75 cfs
Storm frequency = 100 yrs Time to peak = 12.00 hrs
Time interval = 2 min Hyd. volume = 164,039 cuft
Drainage area = 24.450 ac Curve number = 90*
Basin Slope = 0.0 % Hydraulic length = 0 ft
Tc method = TR55 Time of conc. (Tc) = 13.20 min
Total precip. = 2.79 in Distribution = Type II
Storm duration = 24 hrs Shape factor = 484
* Composite (Area/CN) = [(5.000 x 74) + (19.450 x 94)] / 24.450
37
0 2 4 6 8 10 12 14 16 18 20 22 24 26
Q (cfs)
0.00 0.00
10.00 10.00
20.00 20.00
30.00 30.00
40.00 40.00
50.00 50.00
60.00 60.00
70.00 70.00
Q (cfs)
Time (hrs)
Basin A
Hyd. No. 1 -- 100 Year
Hyd No. 1
Hydrograph Report
Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2023 Wednesday, 10 / 25 / 2023
Hyd. No. 2
Basin B
Hydrograph type = SCS Runoff Peak discharge = 58.41 cfs
Storm frequency = 100 yrs Time to peak = 12.03 hrs
Time interval = 2 min Hyd. volume = 169,946 cuft
Drainage area = 22.360 ac Curve number = 94
Basin Slope = 0.0 % Hydraulic length = 0 ft
Tc method = TR55 Time of conc. (Tc) = 16.00 min
Total precip. = 2.79 in Distribution = Type II
Storm duration = 24 hrs Shape factor = 484
38
0 2 4 6 8 10 12 14 16 18 20 22 24 26
Q (cfs)
0.00 0.00
10.00 10.00
20.00 20.00
30.00 30.00
40.00 40.00
50.00 50.00
60.00 60.00
Q (cfs)
Time (hrs)
Basin B
Hyd. No. 2 -- 100 Year
Hyd No. 2
Hydrograph Report
Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2023 Wednesday, 10 / 25 / 2023
Hyd. No. 3
BASIN C
Hydrograph type = SCS Runoff Peak discharge = 93.21 cfs
Storm frequency = 100 yrs Time to peak = 12.07 hrs
Time interval = 2 min Hyd. volume = 294,037 cuft
Drainage area = 63.310 ac Curve number = 83
Basin Slope = 0.0 % Hydraulic length = 0 ft
Tc method = TR55 Time of conc. (Tc) = 16.90 min
Total precip. = 2.79 in Distribution = Type II
Storm duration = 24 hrs Shape factor = 484
39
0 2 4 6 8 10 12 14 16 18 20 22 24 26
Q (cfs)
0.00 0.00
10.00 10.00
20.00 20.00
30.00 30.00
40.00 40.00
50.00 50.00
60.00 60.00
70.00 70.00
80.00 80.00
90.00 90.00
100.00 100.00
Q (cfs)
Time (hrs)
BASIN C
Hyd. No. 3 -- 100 Year
Hyd No. 3
Hydrograph Report
Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2023 Wednesday, 10 / 25 / 2023
Hyd. No. 4
BASIN D
Hydrograph type = SCS Runoff Peak discharge = 50.41 cfs
Storm frequency = 100 yrs Time to peak = 12.57 hrs
Time interval = 2 min Hyd. volume = 364,919 cuft
Drainage area = 51.200 ac Curve number = 92
Basin Slope = 0.0 % Hydraulic length = 0 ft
Tc method = TR55 Time of conc. (Tc) = 68.30 min
Total precip. = 2.79 in Distribution = Type II
Storm duration = 24 hrs Shape factor = 484
40
0 2 4 6 8 10 12 14 16 18 20 22 24 26
Q (cfs)
0.00 0.00
10.00 10.00
20.00 20.00
30.00 30.00
40.00 40.00
50.00 50.00
60.00 60.00
Q (cfs)
Time (hrs)
BASIN D
Hyd. No. 4 -- 100 Year
Hyd No. 4
Hydrograph Report
Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2023 Wednesday, 10 / 25 / 2023
Hyd. No. 5
BASIN E
Hydrograph type = SCS Runoff Peak discharge = 73.25 cfs
Storm frequency = 100 yrs Time to peak = 12.00 hrs
Time interval = 2 min Hyd. volume = 197,517 cuft
Drainage area = 24.570 ac Curve number = 94
Basin Slope = 0.0 % Hydraulic length = 0 ft
Tc method = TR55 Time of conc. (Tc) = 12.40 min
Total precip. = 2.79 in Distribution = Type II
Storm duration = 24 hrs Shape factor = 484
41
0 2 4 6 8 10 12 14 16 18 20 22 24 26
Q (cfs)
0.00 0.00
10.00 10.00
20.00 20.00
30.00 30.00
40.00 40.00
50.00 50.00
60.00 60.00
70.00 70.00
80.00 80.00
Q (cfs)
Time (hrs)
BASIN E
Hyd. No. 5 -- 100 Year
Hyd No. 5
Hydrograph Report
Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2023 Wednesday, 10 / 25 / 2023
Hyd. No. 6
BAXTER CREEK CULVERT
Hydrograph type = Combine Peak discharge = 300.95 cfs
Storm frequency = 100 yrs Time to peak = 12.03 hrs
Time interval = 2 min Hyd. volume = 1,190,461 cuft
Inflow hyds. = 1, 2, 3, 4, 5 Contrib. drain. area = 185.890 ac
42
0 2 4 6 8 10 12 14 16 18 20 22 24 26
Q (cfs)
0.00 0.00
40.00 40.00
80.00 80.00
120.00 120.00
160.00 160.00
200.00 200.00
240.00 240.00
280.00 280.00
320.00 320.00
Q (cfs)
Time (hrs)
BAXTER CREEK CULVERT
Hyd. No. 6 -- 100 Year
Hyd No. 6 Hyd No. 1 Hyd No. 2 Hyd No. 3
Hyd No. 4 Hyd No. 5
Hydraflow Rainfall Report
43
Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2023 Wednesday, 10 / 25 / 2023
Return Intensity-Duration-Frequency Equation Coefficients (FHA)
Period
(Yrs) B D E (N/A)
1 0.0000 0.0000 0.0000 --------
2 69.8703 13.1000 0.8658 --------
3 0.0000 0.0000 0.0000 --------
5 79.2597 14.6000 0.8369 --------
10 88.2351 15.5000 0.8279 --------
25 102.6072 16.5000 0.8217 --------
50 114.8193 17.2000 0.8199 --------
100 127.1596 17.8000 0.8186 --------
File name: SampleFHA.idf
Intensity = B / (Tc + D)^E
Return Intensity Values (in/hr)
Period
(Yrs) 5 min 10 15 20 25 30 35 40 45 50 55 60
1 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00
2 5.69 4.61 3.89 3.38 2.99 2.69 2.44 2.24 2.07 1.93 1.81 1.70
3 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00
5 6.57 5.43 4.65 4.08 3.65 3.30 3.02 2.79 2.59 2.42 2.27 2.15
10 7.24 6.04 5.21 4.59 4.12 3.74 3.43 3.17 2.95 2.77 2.60 2.46
25 8.25 6.95 6.03 5.34 4.80 4.38 4.02 3.73 3.48 3.26 3.07 2.91
50 9.04 7.65 6.66 5.92 5.34 4.87 4.49 4.16 3.88 3.65 3.44 3.25
100 9.83 8.36 7.30 6.50 5.87 5.36 4.94 4.59 4.29 4.03 3.80 3.60
Tc = time in minutes. Values may exceed 60.
Rainfall Precipitation Table (in)
Precip. file name: Sample.pcp
Storm
Distribution 1-yr 2-yr 3-yr 5-yr 10-yr 25-yr 50-yr 100-yr
SCS 24-hour 0.00 1.20 0.00 3.30 1.90 2.28 2.58 2.79
SCS 6-Hr 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00
Huff-1st 0.00 0.00 0.00 2.75 0.00 0.00 0.00 0.00
Huff-2nd 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00
Huff-3rd 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00
Huff-4th 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00
Huff-Indy 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00
Custom 0.00 0.00 0.00 2.80 0.00 0.00 0.00 0.00
Hydraflow Table of Contents Hydrograph.gpw
Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2023 Wednesday, 10 / 25 / 2023
Watershed Model Schematic...................................................................................... 1
Hydrograph Return Period Recap............................................................................. 2
2 - Year
Summary Report......................................................................................................................... 3
Hydrograph Reports................................................................................................................... 4
Hydrograph No. 1, SCS Runoff, Basin A.................................................................................. 4
TR-55 Tc Worksheet............................................................................................................ 5
Hydrograph No. 2, SCS Runoff, Basin B.................................................................................. 6
TR-55 Tc Worksheet............................................................................................................ 7
Hydrograph No. 3, SCS Runoff, BASIN C................................................................................ 8
TR-55 Tc Worksheet............................................................................................................ 9
Hydrograph No. 4, SCS Runoff, BASIN D.............................................................................. 10
TR-55 Tc Worksheet.......................................................................................................... 11
Hydrograph No. 5, SCS Runoff, BASIN E.............................................................................. 12
TR-55 Tc Worksheet.......................................................................................................... 13
Hydrograph No. 6, Combine, BAXTER CREEK CULVERT................................................... 14
10 - Year
Summary Report....................................................................................................................... 15
Hydrograph Reports................................................................................................................. 16
Hydrograph No. 1, SCS Runoff, Basin A................................................................................ 16
Hydrograph No. 2, SCS Runoff, Basin B................................................................................ 17
Hydrograph No. 3, SCS Runoff, BASIN C.............................................................................. 18
Hydrograph No. 4, SCS Runoff, BASIN D.............................................................................. 19
Hydrograph No. 5, SCS Runoff, BASIN E.............................................................................. 20
Hydrograph No. 6, Combine, BAXTER CREEK CULVERT................................................... 21
25 - Year
Summary Report....................................................................................................................... 22
Hydrograph Reports................................................................................................................. 23
Hydrograph No. 1, SCS Runoff, Basin A................................................................................ 23
Hydrograph No. 2, SCS Runoff, Basin B................................................................................ 24
Hydrograph No. 3, SCS Runoff, BASIN C.............................................................................. 25
Hydrograph No. 4, SCS Runoff, BASIN D.............................................................................. 26
Hydrograph No. 5, SCS Runoff, BASIN E.............................................................................. 27
Hydrograph No. 6, Combine, BAXTER CREEK CULVERT................................................... 28
50 - Year
Summary Report....................................................................................................................... 29
Hydrograph Reports................................................................................................................. 30
Hydrograph No. 1, SCS Runoff, Basin A................................................................................ 30
Hydrograph No. 2, SCS Runoff, Basin B................................................................................ 31
Hydrograph No. 3, SCS Runoff, BASIN C.............................................................................. 32
Hydrograph No. 4, SCS Runoff, BASIN D.............................................................................. 33
Hydrograph No. 5, SCS Runoff, BASIN E.............................................................................. 34
Hydrograph No. 6, Combine, BAXTER CREEK CULVERT................................................... 35
Contents continued...Hydrograph.gpw
100 - Year
Summary Report....................................................................................................................... 36
Hydrograph Reports................................................................................................................. 37
Hydrograph No. 1, SCS Runoff, Basin A................................................................................ 37
Hydrograph No. 2, SCS Runoff, Basin B................................................................................ 38
Hydrograph No. 3, SCS Runoff, BASIN C.............................................................................. 39
Hydrograph No. 4, SCS Runoff, BASIN D.............................................................................. 40
Hydrograph No. 5, SCS Runoff, BASIN E.............................................................................. 41
Hydrograph No. 6, Combine, BAXTER CREEK CULVERT................................................... 42
IDF Report.................................................................................................................. 43
Appendix D: Farmers Canal to Baxter
Creek Headgate Calculations
HY-8 Culvert Analysis Report
Crossing Discharge Data
Discharge Selection Method: Specify Minimum, Design, and Maximum Flow
Minimum Flow: 0.00 cfs
Design Flow: 30.00 cfs
Maximum Flow: 60.00 cfs
Table 1 - Summary of Culvert Flows at Crossing: Farmers Canal Heagate on
Baxter
Headwater
Elevation (ft)
Total
Discharge
(cfs)
Culvert 1
Discharge
(cfs)
Roadway
Discharge
(cfs)
Iterations
5.00 0.00 0.00 0.00 1
6.03 6.00 6.00 0.00 1
6.49 12.00 12.00 0.00 1
6.89 18.00 18.00 0.00 1
7.26 24.00 24.00 0.00 1
7.61 30.00 30.00 0.00 1
7.98 36.00 36.00 0.00 1
8.36 42.00 42.00 0.00 1
8.78 48.00 48.00 0.00 1
9.07 54.00 51.74 2.23 13
9.15 60.00 52.74 7.22 6
9.00 50.85 50.85 0.00 Overtopping
Rating Curve Plot for Crossing: Farmers Canal Heagate on Baxter
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)
Inlet
Con
trol
Dep
th
(ft)
Outl
et
Con
trol
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
Velo
city
(ft/s)
0.00
cfs
0.00
cfs
5.00 0.00 0.00
0
0-
NF
0.00 0.00 0.0
0
0.00 0.00 0.00
6.00
cfs
6.00
cfs
6.03 1.03 0.0* 1-
S2
n
0.63 0.77 0.6
4
0.60 5.46 2.77
12.00
cfs
12.00
cfs
6.49 1.49 0.20
5
1-
S2
n
0.90 1.10 0.9
0
0.90 6.73 3.43
18.00
cfs
18.00
cfs
6.89 1.89 0.59
5
1-
S2
n
1.11 1.36 1.1
2
1.13 7.46 3.85
24.00 24.00 7.26 2.26 1.00 1-1.31 1.58 1.3 1.33 8.05 4.18
cfs cfs 1 S2
n
1
30.00
cfs
30.00
cfs
7.61 2.61 1.43
4
1-
S2
n
1.48 1.77 1.5
0
1.50 8.52 4.44
36.00
cfs
36.00
cfs
7.98 2.98 1.90
0
1-
S2
n
1.65 1.95 1.6
7
1.66 8.91 4.66
42.00
cfs
42.00
cfs
8.36 3.36 2.40
4
5-
S2
n
1.83 2.11 1.8
4
1.80 9.24 4.86
48.00
cfs
48.00
cfs
8.78 3.78 3.31
7
5-
S2
n
2.00 2.26 2.0
1
1.93 9.51 5.03
54.00
cfs
51.74
cfs
9.07 4.07 3.63
1
5-
S2
n
2.12 2.34 2.1
3
2.06 9.65 5.19
60.00
cfs
52.74
cfs
9.15 4.15 3.71
9
5-
S2
n
2.15 2.36 2.1
6
2.17 9.69 5.34
* Full Flow Headwater elevation is below inlet invert.
Culvert Barrel Data
Culvert Barrel Type Straight Culvert
Inlet Elevation (invert): 5.00 ft,
Outlet Elevation (invert): 4.00 ft
Culvert Length: 35.01 ft,
Culvert Slope: 0.0286
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: 5.00 ft
Outlet Station: 35.00 ft
Outlet Elevation: 4.00 ft
Number of Barrels: 1
Culvert Data Summary - Culvert 1
Barrel Shape: Circular
Barrel Diameter: 3.00 ft
Barrel Material: Corrugated Steel
Embedment: 0.00 in
Barrel Manning's n: 0.0240
Culvert Type: Straight
Inlet Configuration: Square Edge with Headwall (Ke=0.5)
Inlet Depression: None
Tailwater Data for Crossing: Farmers Canal Heagate on Baxter
Table 2 - Downstream Channel Rating Curve (Crossing: Farmers Canal Heagate on
Baxter)
Flow (cfs) Water
Surface
Elev (ft)
Velocity
(ft/s)
Depth (ft) Shear (psf) Froude
Number
0.00 4.00 0.00 0.00 0.00 0.00
6.00 4.60 0.60 2.77 0.45 0.68
12.00 4.90 0.90 3.43 0.67 0.71
18.00 5.13 1.13 3.85 0.85 0.72
24.00 5.33 1.33 4.18 0.99 0.73
30.00 5.50 1.50 4.44 1.12 0.74
36.00 5.66 1.66 4.66 1.24 0.74
42.00 5.80 1.80 4.86 1.35 0.75
48.00 5.93 1.93 5.03 1.45 0.75
54.00 6.06 2.06 5.19 1.54 0.76
60.00 6.17 2.17 5.34 1.63 0.76
Tailwater Channel Data - Farmers Canal Heagate on Baxter
Tailwater Channel Option: Trapezoidal Channel
Bottom Width: 3.00 ft
Side Slope (H:V): 1.00 (_:1)
Channel Slope: 0.0120
Channel Manning's n: 0.0350
Channel Invert Elevation: 4.00 ft
Roadway Data for Crossing: Farmers Canal Heagate on Baxter
Roadway Profile Shape: Constant Roadway Elevation
Crest Length: 50.00 ft
Crest Elevation: 9.00 ft
Roadway Surface: Gravel
Roadway Top Width: 30.00 ft