Final Percent Joe Tank Hydraulics Report.pdf

CENTRAL FEDERAL LANDS HIGHWAY DIVISION

100 PERCENT HYDRAULICS REPORT

JOE TANK ROAD

NAVAJO COUNTY, ARIZONA

PROJECT #32782022

DECEMBER 14, 2022

100 PERCENT

HYDRAULICS

REPORT

JOE TANK ROAD

NAVAJO COUNTY, ARIZONA

CENTRAL FEDERAL LANDS

HIGHWAY DIVISION

PROJECT NO.: 32782022

DATE: DECEMBER 14, 2022

WSP

2000 S. COLORADO BLVD., STE. 2-1000

DENVER, CO 80222

T: +0 303-935-6505

F: +0 303-935-6575

WSP.COM

100 Percent Hydraulic Report Project No. 32782202 Central Federal Lands

WSP

December 2022

Page i

EXECUTIVE SUMMARY

Hydrologic and hydraulic analyses were conducted for the AZ FLAP FR136 Joe Tank Road project located in

Navajo County, Arizona. Proposed improvements include widening the roadway, new asphalt, modifications to existing culverts and drainage ditches, new storm drain, and new curb-and-gutter inlet design. The hydraulic design frequency is the 25-year flood for all cross culverts and the 10-year flood for all side drainages and inlet design.

All design flows were estimated using the Rational Method as presented by the Rational Method Tool developed by the Arizona Department of Transportation (ADOT). Hydraulic analysis of the cross culverts was evaluated using HY-8 (FHWA, 2021), and open channel hydraulics necessary for the roadside ditches were modeled using Bentley FlowMaster V8i (Bentley Systems, Inc., 2009).

All cross culverts and side-drainage culverts will be replaced with corrugated metal pipes. Riprap will provide outlet protection for each culvert and was designed per Federal Highway Administration (FHWA) standard details.

Triangular roadside ditches will convey along the north and south of the proposed roadway until approximately

300 feet west of State Road 260. The remaining 300 feet will be lined with curb and gutter.

Drainage will be mitigated through the curb-and-gutter sections via inlets and a proposed storm sewer. Outlet protection at the storm drain outfall will be a riprap apron.

100 Percent Hydraulics Report

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TABLE OF

CONTENTS

Figure 1: Project Location Map

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TABLE OF

CONTENTS

EXECUTIVE SUMMARY ....................................... I

1 PROJECT BACKGROUND INFORMATION

2 HYDROLOGY

2.1 Hydrologic Setting

2.2 FEMA Flood Insurance Study

2.3 Available Hydrologic Data

3 HYDRAULIC DESIGN CRITERIA

3.1 Determination of Design Discharge

3.1.1 Drainage Basin Delineations

3.1.2 Rational Method

4 EXISTING CONDITIONS MODEL

DEVELOPMENT

4.1 Existing Conditions Culvert and storm sewer

Geometry

4.2 Existing Conditions Model Results

4.2.1 Cross Culverts

4.2.2 Side-Drainage Culverts

5 PROPOSED CONDITIONS MODEL

DEVELOPMENT

5.1 Proposed Conditions Culvert Geometry

5.2 Proposed Conditions Culvert Results

5.3 Proposed Culvert Outlet Protection

5.4 Roadside Ditches

5.5 Inlet Design

5.6 Storm Sewer Design

5.7 Storm Sewer Outlet Protection

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TABLE OF

CONTENTS

6 CONCLUSIONS AND

RECOMMENDATIONS

7 REFERENCES

TABLES

TABLE 1: PDDM HYDRAULIC DESIGN CRITERIA FOR LOW-

STANDARD ROADWAYS

TABLE 2: SUB-BASIN PEAK FLOWS

TABLE 3: EXISTING CROSS-CULVERT GEOMETRY

TABLE 4: EXISTING SIDE-DRAINAGE CULVERT GEOMETRY

TABLE 5: EXISTING STORM SEWER GEOMETRY

TABLE 6: EXISTING CONDITIONS HYDRAULIC RESULTS

FOR THE DESIGN EVENT

TABLE 7: EXISTING CONDITIONS HYDRAULIC RESULTS

FOR THE DESIGN EVENT

TABLE 8: PROPOSED CROSS-CULVERT GEOMETRY

TABLE 9: PROPOSED SIDE-DRAINAGE CULVERT

GEOMETRY

TABLE 10: PROPOSED CONDITIONS CROSS CULVERTS –

HYDRAULIC RESULTS FOR THE 25-YEAR

DESIGN EVENT

TABLE 11: PROPOSED CONDITIONS SIDE-DRAINAGE

CULVERTS – HYDRAULIC RESULTS FOR

THE 10-YEAR DESIGN EVENT

TABLE 12: PROPOSED RIPRAP APRON DIMENSIONS FOR

CULVERTS

TABLE 13: MAXIMUM DITCH PEAK FLOWS (10-YEAR

DESIGN EVENT)

TABLE 14: STORM SEWER PROPOSED RIPRAP APRON AT

OUTLET

FIGURES

FIGURE 1: PROJECT LOCATION MAP .................................. II

FIGURE 2: EXISTING CULVERTS

FIGURE 3: DRAINAGE BASIN MAP

FIGURE 4: EXCERPT OF FHWA CLFHD DETAIL FOR

PLACED RIPRAP AT CULVERT OUTLETS

(FHWA, 2021)

APPENDICES

APPENDIX A: FIRMETTE – PORTION OF MAP NUMBER

04017C4488F

APPENDIX B: PEAK FLOW ADOT RATIONAL METHOD

RESULTS

APPENDIX C: EXISTING CONDITIONS MODELING RESULTS

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TABLE OF

CONTENTS

APPENDIX D: PROPOSED CONDITIONS MODELING

RESULTS

APPENDIX E: MARICOPA ASSOCIATION OF

GOVERNMENTS CATCH BASIN TYPE “E”

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December 2022

1 PROJECT BACKGROUND

INFORMATION

The Federal Highway Administration (FHWA), Central Federal Lands Highway Division (CFLHD) in partnership with the City of Show Low and the United Stated Forest Service (USFS) will be improving approximately 3,170 feet (0.60 miles) of Joe Tank Road from State Route 260 to Apache-Sitgreaves National

Forest Land.

Joe Tank Road will be widened from 20 feet to 28 feet, adding a paved shoulder to both sides. Existing drainage ditches, cross culverts, and side-drainage culverts must be modified to accommodate the wider roadway. In conjunction with the widening of the road, approximately 300 feet of curb and gutter will be installed in lieu of roadside ditches.

Across the project site, six cross culverts, three side-drainage culverts, and storm sewer infrastructure are designed as part of this project.

2 HYDROLOGY

2.1 HYDROLOGIC SETTING

The project is located entirely within Navajo County, Arizona in the Apache-Sitgreaves National Forest just west of the City of Show Low.

Joe Tank Road runs along a ridgeline between steep forest land and a subdivision. Overland flow that is not captured by the subdivision’s drainage infrastructure generally drains toward Joe Tank Road.

2.2 FEMA FLOOD INSURANCE STUDY

The Federal Emergency Management Agency (FEMA) provides flood insurance rate maps that detail special flood hazard areas. Land that is inundated by the base (100-year) flood are subject to National Flood Insurance

Program (NFIP) floodplain management regulations.

The national flood hazard map indicates that the project limits for Joe Tank Road fall within Zone X. FEMA

Zone X is defined as an area outside of the 500-year flood zone. A FEMA FIRMette is included in Appendix A that presents FEMA floodplain mapping near Joe Tank Road project site.

2.3 AVAILABLE HYDROLOGIC DATA

The project site does not include any National Hydrography Dataset (NHD) stream crossings. No flow records are available at the project site.

3 HYDRAULIC DESIGN CRITERIA

The Federal Lands Highway (FLH) Project Development and Design Manual (PDDM) establishes the hydraulic design criteria for this project (FLH, 2012). Joe Tank Road has a speed limit of 25 miles per hour and an average daily traffic (ADT) estimate of 250. The relatively slow speed and low traffic volume indicate that the roadway should be classified as “low standard” for hydraulic design purposes. The corresponding PDDM hydraulic design criterion are detailed in Table 1.

Hydraulic adequacy for roadway culverts is determined by conformance to all applicable design criterion including allowable headwater (AHW) and the respective headwater to depth ratio (HW/D).

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December 2022

The design event for cross culverts on a low-standard roadway is the 25-year event. Roadside ditches, driveway culverts, and storm sewer inlet design must be designed to meet the 10-year event.

In the PDDM, three sets of criteria are used to determine the allowable headwater elevation:

1. New versus existing culvert,

2. Ratio of headwater depth to culvert diameter or rise (HW/D), and

3. Site-specific reference elevations.

There are no site-specific reference elevations that would represent unacceptable hazards at any of the culvert locations.

The FLH prefers cross culverts be replaced with pipe sizes no smaller than 24 inches. The minimum size for culverts in the drainage ditch is 18 inches. Design exceptions may be requested via the procedures outlined in the PDDM Section 9.1.3.

Figure 2 presents the existing drainage conditions along Joe Tank Road.

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December 2022

Table 1: PDDM Hydraulic Design Criteria for Low-Standard Roadways

TOPIC DESIGN EVENT CRITERIA VALUE

Cross Culvert Design Flood: 25-Year

Check Flood: Overtopping

Allowable Headwater (AHW) New: AHW ≤ bottom of aggregate base layer

Existing: AHW ≤ shoulder hinge point.

Headwater to Structure Depth Ratio

(HW/D)

48 inches or smaller: HW/D ≤ 1.5

Larger than 48 inches: HW/D ≤ 1.2

Minimum Size 24 inches

Slope Stream Crossings: Match Streambed

Ditch Relief: Min 2%, Max 10%

Ditches Capacity Design: 10-Year

Permanent Linings: 10-Year

Flood

Temporary Linings: 2-Year Flood

Depth New: WSEL ≤ Bottom of Aggregate Base Layer

Existing: WSEL ≤ Shoulder Hinge Point

Existing: WSEL ≤ Shoulder Hinge

Point

Minimum 0.5%

Slope Permissible shear stress

Pavement

Drainage

Design Flood: 10-Year

Sumps: 50-Year

Spread Half of One Travel Lane

Depth On-Grade and Sags: Allowable spread, not to exceed curb height

Sumps and Parking Areas: 6 inches

Inlet Clogging Factor 50%

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December 2022

Figure 2: Existing Culverts

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3.1 DETERMINATION OF DESIGN DISCHARGE

3.1.1 DRAINAGE BASIN DELINEATIONS

The contributing drainage basins for each crossing along the project corridor were delineated against a 1-meter resolution Digital Elevation Model (DEM) coupled with detailed survey along the existing Joe Tank Road corridor. The 1-meter DEM encompassing the project site was published by the USFS in 2019 (Quantum

Spatial, Inc., 2019).

The City Engineer for the City of Show Low verified that the subdivision south of Joe Tank Road contains a raised curb-and-gutter system, so the sub-basin delineations (See Figure 3) account for this independent drainage system. Note that sub-basin South 1 includes a region where an existing culvert conveys flow from the subdivision towards Joe Tank Road.

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December 2022

Figure 3: Drainage Basin Map

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December 2022

3.1.2 RATIONAL METHOD

The drainage basins contributing to the culverts and roadside ditches along Joe Tank Road were relatively small and generally uniform in slope and coverage. Peak flows from the 11 drainage sub-basins along Joe Tank Road were estimated using the Rational Method Tool available on the ADOT website (ADOT, 2014).

Landcover was characterized as “developed” based on aerial imagery from the ArcGIS Pro base maps.

Imperviousness across the sub-basins ranged from approximately 10 to 90 percent.

Rainfall intensity values were obtained at the centroid of the contributing watershed using the National Oceanic and Atmospheric Administration (NOAA) Atlas 14-point precipitation frequency server (NOAA, 2017). The time of concentration was calculated for each sub-basin directly within ADOT’s Rational Method tool based on inputs for the longest flow path and sub-basin slope.

Table 2 presents the maximum design peak flows from each drainage sub-basin. A full presentation of output from the ADOT Rational Method tool is included in Appendix B.

Table 2: Sub-basin Peak Flows

DRAINAGE

SUB-

BASIN

PEAK FLOW (CFS)

2-YEAR 5-YEAR

10-

YEAR

25-

YEAR

50-

YEAR

100-

YEAR

South 1 22.4 35.8 46.9 63.5 76.0 90.0

South 2 5.0 8.0 10.5 14.1 16.9 20.0

South 3 1.9 3.5 4.7 6.4 7.9 9.4

South 4 4.5 7.2 9.4 12.8 15.3 18.1

South 5 2.4 3.7 4.8 6.4 7.6 8.9

South 6 0.6 0.8 1.0 1.3 1.5 1.7

South 7 0.5 0.6 0.8 1.0 1.2 1.3

South 8 0.6 0.9 1.1 1.4 1.6 1.9

North 1 0.7 1.2 1.6 2.2 2.7 3.2

North 2 0.3 0.5 0.7 0.9 1.1 1.3

North 3 0.3 0.5 0.7 0.9 1.2 1.4

4 EXISTING CONDITIONS MODEL

DEVELOPMENT

The repair/replacement design for every cross culvert must meet the FLH HW/D requirements for the design event. Hydraulic analysis was performed for the existing conditions to identify whether any of the cross drainages should be enlarged to comply with the requirements laid out in the PDDM.

The hydraulic performance of the existing culverts was evaluated using the FHWA’s HY-8 Version 7.6 software package (FHWA, 2021). Required input included design discharge, upstream and downstream invert elevations, culvert dimensions, culvert material, inlet type, tailwater data, and roadway data.

Hydraulic analyses of ditch capacities were performed using Bentley FlowMaster V8i (Bentley Systems, Inc., 2009).

All culvert and ditch analyses were based on the flows reported in Table 2.

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4.1 EXISTING CONDITIONS CULVERT AND STORM SEWER

GEOMETRY

Six cross culverts and three side-drainage culverts are to be replaced as part of this project. All existing culverts have a “thin edge projecting” inlet configuration.

Summaries of the existing cross-culvert geometry and side-drainage culvert geometry are provided in Table 3 and Table 4, respectively. A storm sewer system will be included in the proposed design as discussed in later sections. For reference, the existing storm sewer system properties are provided in Table 5.

Table 3: Existing Cross-Culvert Geometry

CULVERT

APPROXIMATE

STATIONING EXISTING PIPE

INVERT INLET

ELEVATION

(FT)

INVERT

OUTLET

ELEVATION

(FT)

ROADWAY

ELEVATION

(NAVD, FT) LENGTH (FT)

107+83 18-inch CMP 6345.91 6344.85 6348.91 35

112+53 12-inch CMP 6364.76 6362.29 6365.89 31

122+20 18-inch CMP 6361.08 6360.52 6367.21 46

126+46 18-inch CMP 6348.38 6348.07 6351.23 58

129+85 18-inch CMP 6342.39 6342.06 6346.39 54

132+05 18-inch CMP 6337.11 6335.32 6340.22 54

Table 4: Existing Side-Drainage Culvert Geometry

CULVERT

APPROXIMATE

STATIONING EXISTING PIPE

INVERT INLET

ELEVATION

INVERT

OUTLET

ELEVATION

(FT)

ROADWAY

ELEVATION

(NAVD, FT)

LENGTH

(FT)

109+53 18-inch CMP 6350.99 6349.30 6350.91 50

129+20 18-inch CMP 6342.99 6342.00 6345.11 72

131+44 18-inch CMP 6340.14 6336.93 6341.98 141

Table 5: Existing Storm Sewer Geometry

APPROXIMATE

STATIONING EXISTING PIPE

INVERT INLET

ELEVATION

INVERT

OUTLET

ELEVATION

(FT)

ROADWAY

ELEVATION

(NAVD, FT)

LENGTH

(FT)

132+44 to

135+74

10x24-inch elliptical CMP

6334.92 6315.81 Varies – storm sewer system

4.2 EXISTING CONDITIONS MODEL RESULTS

Detailed output information for the existing cross and side-drainage culverts is included in Appendix C.

4.2.1 CROSS CULVERTS

A summary of the hydraulic results for the existing conditions cross drainage structures and the 25-year (design) event is shown in Table 6.

The total thickness of the asphalt and base course is approximately 1 foot. Crossings where the headwater elevation exceeds 1 foot lower than the existing roadway surface are indicated in red text to indicate non-compliance. Additionally, three crossings had unallowable headwater to depth ratios for the design event.

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Table 6: Existing Conditions Hydraulic Results for the Design Event

CULVERT

APPROXIMATE

STATIONING

25-YEAR

DESIGN

EVENT

DISCHARGE

HEADWATER

ELEVATION

(NAVD88 FT) HW/D

CULVERT

EXIT

DEPTH

(FT)

CULVERT

EXIT

VELOCITY

(FPS)

CONTRIBUTING

DRAINAGE

AREA

107+83 77.6 6349.27 2.2 1.31 7.26 South 1

South 2

112+53 6.4 6365.94 1.2 0.48 6.84 South 3

122+20 12.8 6365.82 3.0 1.34 7.67 South 4

126+46 6.4 6350.39 1.1 0.98 5.24 South 5

129+85 1.3 6343.09 0.5 0.43 3.14 South 6

132+05 1.0 6337.64 0.5 0.31 3.72 South 7

4.2.2 SIDE-DRAINAGE CULVERTS

A summary of the hydraulic results for the existing conditions side-drainage structures and the 10-year (design) event is shown in Table 7.

Table 7: Existing Conditions Hydraulic Results for the Design Event

CULVERT

APPROXIMATE

STATIONING

10-YEAR

DESIGN

EVENT

DISCHARGE

(CFS)

HEADWATER

ELEVATION

(NAVD88 FT) HW/D

CULVERT

EXIT

DEPTH

(FT)

CULVERT

EXIT

VELOCITY

(FPS)

CONTRIBUTING

DRAINAGE AREA

109+53 10.5 6351.00 0.7 0.58 3.74 South 2

129+20 16.8 6345.21 1.4 1.09 5.76 North 1 South 4 South 5 South 6

131+44 17.50 6342.09 1.3 1.05 5.56 North 1 North 2 South 4 South 5

South 6

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5 PROPOSED CONDITIONS MODEL

DEVELOPMENT

The replacement design for every cross culvert, roadside ditch, and curb-and-gutter inlet must meet CFLHD criteria for their respective design events.

5.1 PROPOSED CONDITIONS CULVERT GEOMETRY

Geotechnical field testing identifies naturally corrosive soils exist at the project site. The City of Show Low has historically had success using corrugated metal piping (CMPs) despite the corrosivity of soils in the area. Per recommendation from the City of Show Low, all replaced culverts will be CMP. Reference the geotechnical investigation for further information.

Summaries of the design geometries for the six proposed cross-culvert geometry and two proposed side-drainage culverts are provided in Table 8 and Table 9, respectively. The side-drainage culvert that is proposed at

Station 109+53 has been separated into two culvert segments by a manhole that intercepts an existing 12-inch line from the southwest. It is assumed that the 12-inch line has a minimal baseflow and will negligibly impact culvert hydraulics for this segment. See Civil Plans for culvert configuration and additional information for culverts at Station 109+53. Detailed model output information for the proposed drainage structures is included in Appendix D.

There is a proposed storm sewer system from station 132+08.76 to 135+91.96. See Section 5.6.

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Table 8: Proposed Cross-Culvert Geometry

CULVERT

APPROXIMATE

STATIONING

ROADWAY

ELEVATION

(NAVD88 FT)

SUBGRADE

ELEVATION

PROPOSED

PIPE(S)

END

TREATMENT

INVERT

INLET

ELEVATION

(NAVD88 FT)

INVERT

OUTLET

ELEVATION

(NAVD88 FT)

LENGTH

(FT)

MAXIMUM

ALLOWABLE

DESIGN HW/D

MAXIMUM

ALLOWABLE

DESIGN

HEADWATER

ELEVATION

(NAVD88 FT)

107+83 6350.15 6348.82 One

54-inch CMP

Square Edge with

Headwall

6343.61 6339.71 49 1.2 6348.82

112+51 6366.36 6365.12 24-inch CMP Flared End

Section

6363.11 6361.35 46 1.5 6365.12

121+18 6366.66 6365.62 Two

24-inch CMP

Flared End

Section

6363.09 6361.80 66 1.5 6365.62

126+46 6351.50 6350.38 18-inch CMP Flared End

Section

6348.52 6347.88 56 1.5 6350.38

129+81 6345.29 6344.10 24-inch CMP Flared End

Section

6342.16 6340.86 49 1.5 6344.10

132+06 6340.38 6339.11 18-inch RCP Into Catch

Basin

6337.26 6335.85 44 1.5 6339.11

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Table 9: Proposed Side-Drainage Culvert Geometry

CULVERT

APPROXIMATE

STATIONING

ROADWAY

ELEVATION

(NAVD88

FT)

SUBGRADE

ELEVATION

PROPOSED

PIPE(S) END TREATMENT

INVERT INLET

ELEVATION

(NAVD88 FT)

INVERT

OUTLET

ELEVATION

(NAVD88

FT)

LENGTH

(FT)

MAXIMUM

ALLOWABLE

DESIGN

HW/D

MAXIMUM

ALLOWABLE

DESIGN

HEADWATER

ELEVATION

(NAVD88 FT)

109+53 (into catch basin)*

6353.14 6352.04 24-inch

CMP

Flared End Section 6349.44 6347.89 48 1.5 6352.04

109+53 (out of catch basin)*

6353.14 6352.04 24-inch

CMP

Flared End Section 6347.89 6347.80 19 1.5 6352.04

129+20 6346.45 6345.41 30-inch

CMP

Flared End Section 6342.73 6341.62 63 1.5 6345.41

131+44 (inlet station

130+73.60)*

6342.78 6341.74 30-inch

RCP

Into Catch Basin 6338.50 6334.00 128 1.5 6341.74

*Refer to Civil Plans for configuration.

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5.2 PROPOSED CONDITIONS CULVERT RESULTS

A summary of the hydraulic results for the proposed culvert replacements is included in Table 10 and Table 11. The design headwater elevation is below the aggregate base course at all crossings and HW/D requirements are met for all culverts. No roadway overtopping is observed during the 100-year event.

Table 10: Proposed Conditions Cross Culverts – Hydraulic Results for the 25-Year Design Event

CULVERT

APPROXIMATE

STATIONING

25-YEAR

DESIGN

EVENT

DISCHARGE

(CFS)

MAXIMUM

ALLOWABLE

MAXIMUM

ALLOWABLE

25-YEAR

DESIGN

HEADWATER

ELEVATION

(NAVD88 FT)

25-YEAR

DESIGN

HEADWATER

ELEVATION

(NAVD88 FT) HW/D

CULVERT

EXIT

DEPTH

(FT)

CULVERT

EXIT

VELOCITY

(FPS)

APPROXIMATE

TAILWATER

DEPTH

(FT)

APPROXIMATE

TAILWATER

VELOCITY

(FPS)

CONTRIBUTING

DRAINAGE

AREA

107+83 77.6 6348.82 6347.25 0.81 1.63 14.92 2.19 5.38 South 1

South 2

112+51 6.4 6365.12 6364.47 0.68 0.70 6.47 0.70 4.36 South 3

121+18 12.8 6365.62 6350.21 0.63 0.85 5.07 0.97 4.52 South 4

126+46 6.4 6350.38 6350.21 1.13 0.98 5.24 0.84 3.04 South 5

129+81 1.3 6344.10 6342.73 0.29 0.34 3.59 0.46 2.04 South 6

132+06 1.0 6339.11 6337.76 0.33 0.23 5.99 0.42 1.91 South 7

Table 11: Proposed Conditions Side-Drainage Culverts – Hydraulic Results for the 10-Year Design Event

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CULVERT

APPROXIMATE

STATIONING

10-YEAR

DESIGN

EVENT

DISCHARGE

(CFS)

MAXIMUM

ALLOWABLE

10-YEAR

DESIGN

HEADWATER

ELEVATION

(NAVD88 FT)

10-YEAR

DESIGN

HEADWATER

ELEVATION

(NAVD88 FT) HW/D

CULVERT

EXIT DEPTH

(FT)

CULVERT

EXIT

VELOCITY

(FPS)

APPROXIMATE

TAILWATER

DEPTH

(FT)

APPROXIMATE

TAILWATER

VELOCITY

(FPS)

CONTRIBUTING

DRAINAGE

AREA

109+53 (into catch basin)

10.50 6351.58 6351.31 0.94 0.97 6.94 1.04 3.26 South 2

109+53 (out of catch basin)

10.50 6351.58 6349.90 0.95 1.16 5.55 1.04 3.26 South 2

129+20 16.80 6345.41 6344.85 0.85 1.35 6.21 1.20 3.87 North 1

South 4

South 5

South 6

131+44 (inlet station

130+73.60)

17.50 6341.74 6340.62 0.80 0.79 13.08 0.44 4.00 North 1

North 2

South 4

South 5

South 6

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December 2022

5.3 PROPOSED CULVERT OUTLET PROTECTION

Outlet protection for all proposed culverts was designed according to the methods outlined in the FHWA’s

CFLHD Detail for Placed Riprap at Culvert Outlets (FHWA, 2006). The minimum required riprap sizes for cross culverts and side-drainage culverts were based on their respective parameters according to the FHWA’s

Standard Detail (FHWA, 2021). A 54-inch culvert is not included in the FHWA Standard Detail; however, the dimensions and riprap class were extrapolated with additional conservancy included.

Table 12: Proposed Riprap Apron Dimensions for Culverts

CULVERT

APPROXIMATE

STATIONING

FHWA RIPRAP

CLASS

APRON LENGTH

(FT)

APRON THICKNESS

(FT)

107+83 Class 4 30 2.5

109+53 (into catch basin)

Culvert connects directly to catch basin

109+53 (out of catch basin)

Class 2 8 1.5

112+51 Class 2 8 1.5

121+18 Class 2 8 1.5

126+46 Class 2 6 1.5

129+20 Class 3 12.5 2

129+81 Class 2 8 1.5

131+44 Culvert connects directly to catch basin

132+06 Culvert connects directly to catch basin

Figure 4: Excerpt of FHWA CLFHD Detail for Placed Riprap at Culvert Outlets (FHWA, 2021)

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5.4 ROADSIDE DITCHES

The PDDM requires that roadside ditches be designed to convey the 10-year event with a maximum water surface elevation no higher than the bottom of the aggregate base layer. Proposed roadside ditch cross-sections were designed using Bentley FlowMaster V8i (Bentley Systems, Inc., 2009).

The proposed grass-lined ditches are not expected to carry a baseflow. A Manning’s roughness coefficient of

0.035 was selected to represent the proposed ditch coverage. Calculated 10-year design velocities are below 5 feet per second and are not expected to scour or erode the grass-lined roadside ditches.

The proposed ditch cross-sections are triangular with 1:3 (H:V) and 1:4 (H:V) side slopes. Roadside ditches are identified by their approximate stationing noted on the design plan set. A summary of the approximate stationing, channel location, slope, and minimum channel depths to maintain compliance with the PDDM are presented in Table 13.

Table 13: Maximum Ditch Peak Flows (10-Year Design Event)

APPROXIMATE

STATIONING

(FT)

CHANNEL

SLOPE

(FT/FT)

10-YEAR

PEAK

FLOW

(CFS)

10-YEAR

DEPTH

(FT)

10-YEAR

VELOCITY

(FPS)

UPSTREAM

DRAINAGE

AREA

DOWNSTREAM

ROUTING

CULVERT

STATION

North Ditch

120+50 to

130+67

0.01745 16.8 1.01 4.68 South 4

South 5

South 6

North 1

131+44 to catch basin

South Ditch

104+68 to

112+56

0.01523 57.4 1.84 4.83 South 1

South 2

107+83

112+56 to

116+68.75

0.04596 4.7 0.59 3.91 South 3 112+51

116+68.75 to

121+02

0.03176 9.4 0.81 4.05 South 4 121+18

121+02 to

126+28

0.03176 4.8 0.63 3.42 South 5 126+46

126+28 to

129+73

0.01745 1.0 0.39 1.85 South 6 129+81

129+73 to

132+04

0.01745 0.8 0.36 1.75 South 7 132+06 to catch basin

5.5 INLET DESIGN

The proposed inlet design for the curb-and-gutter section is based on the standard details presented in adjacent

Maricopa County standard details for a Catch Basin Type “E”. The City of Show Low uses Maricopa

Association of Governments standard details. The PDDM specifies that the design storm for inlets is the 10-year event.

The roadside ditches from approximately station 129+73 to 132+04 south and 120+50 to 130+67 north drain to culverts at Station 132+06 and 131+44, respectively. Culverts at Station 132+06 and 131+45 are proposed to connect directly to a 60-inch storm drain manhole at station 132+08.76 just north of Joe Tank Road. Roadway drainage past the culverts at stations 132+06 and 131+45 will be accommodated with the proposed curb-and-gutter inlet design.

Central Federal Lands

WSP

December 2022

The curb-and-gutter inlet design includes Catch Basin Type “E” inlets on both the south and north of the proposed Joe Tank Road (See Appendix E for the referenced standard detail).

5.6 STORM SEWER DESIGN

The proposed 24-inch trunkline begins at a catch basin at station 132+08.76 and runs along the northwest side of

Joe Tank Road at a 4.68% slope to a manhole at station 133+96.50 and then to another manhole at a 4.01% slope at station 135+30.42. The slope of the trunkline in this area must be less than 5% to ensure velocities are below 15 feet per second. Storm drain inlets at the east end of Joe Tank Road (at approximately station 135+30) will drain via 18-inch reinforced concrete pipes (RCPs) with a slope between 0.96% to 1.00% to the manhole at station 135+30.42. These 18-inch RCP’s must have a maximum slope of 11%. From there, stormwater will flow through a 30-inch RCP at a slope of 0.50% to the outfall at 135+91.96.

5.7 STORM SEWER OUTLET PROTECTION

Outlet protection for the storm drain system was designed using the FHWA table presented in Section 5.3. A proposed riprap apron has the riprap class and dimensions summarized in Table 14.

Table 14: Storm Sewer Proposed Riprap Apron at Outlet

FHWA RIPRAP CLASS

APRON LENGTH

(FT) APRON THICKNESS (FT)

Class 3 16 2

6 CONCLUSIONS AND

RECOMMENDATIONS

As part of the 100 percent design submittal, WSP has the following recommendations:

1. All cross culverts should be replaced with CMPs. All culverts not directly connecting to the storm drain system shall have riprap aprons at the outlet.

2. Triangular roadside ditches will line most of the proposed roadway. A curb-and-gutter system is proposed for the approximately 300-feet length of section nearest State Route 260.

3. A new storm sewer trunkline is proposed through the curb-and-gutter section of the proposed roadway.

Stormwater will be routed to the trunkline via two manholes and on-grade inlets.

4. The outlet of the storm drain system where the pipe daylights is proposed to have a riprap apron consisting of FHWA Class 3 riprap with a length of 16 feet and thickness of two feet.

5. Refer to Table 8 and Table 9 for recommended culvert sizes and Table 12 for riprap recommendations.

7 REFERENCES

ADOT. (2014). Highway Drainage Design Manual, Volume 2: Hydrology Second Edition. Phoenix, AZ:

Arizona Department of Transportation.

Bentley Systems, Inc. (2009). FlowMaster V8i (SELECTseries1). Watertown, CT: Bentley.

FHWA. (2006). Hydraulic Engineering Circular No. 14 – Hydraulic Design of Energy Dissipators for

Culverts and Channels, Chapter 10: Riprap Basins and Aprons. U.S. Department of

Transportation.

FHWA. (2021). FP-14 Standard Specifications: Table 705-1 Gradation Requirements for Riprap. U.S.

Department of Transportation, Federal Lands Highway.

Central Federal Lands

WSP

December 2022

FHWA. (2021). HY-8 7.60. Environmental Modeling Research Laboratory: Aquaveo LLC.

FLH. (2012). Project Development and Design Manual, Chapter 7 Hydrology and Hydraulics. Federal

Highway Administration.

NOAA. (2017). NOAA Atlas 14, Volume 6, Version 2: Point Precipitation Frequency Server. Silver Spring, MD: National Weather Service.

Quantum Spatial, Inc. (2019). 3DEP Prozessing AZ LiDAR Quality Level 1 (QL1) Standards. USFS.

USGS. (2021). USGS 1/3 Arc Second n35w111 20210811. U.S. Geological Survey.

APPENDIX

Appendix A: FIRMette – Portion of Map

Number 04017C4488F

Appendix A - FIRMette - Portion of Map Number 04017C4488F A-1

Appendix B: Peak Flow ADOT Rational

Method Results

ADOT RATIONAL METHOD PROGRAM

Compution Date and Time: 05/24/2022 14:49:47

Project Name: Joe Tank Road Project Location: Navajo County, Arizona Company: Wood PLC Project Notes:

Prepared by: CAF Prepared by date: 5/19/2022

Checked by: JAH Checked by date: 5/19/2022

Summary Table for 2-Year event:

Rational Rainfall Time of Time of Subbasin ID Discharge Coeff. Intensity Area Concentration Concentration Q C i A Computed Tc Applied Tc (cfs) (inches/hour) (acres) (minutes) (minutes) South 1 22.4 0.40 3.02 18.59 5.8 10.0* South 2 5.0 0.40 3.02 4.14 4.7 10.0* South 3 1.9 0.30 3.02 2.14 6.1 10.0* South 4 4.5 0.40 3.02 3.74 7.8 10.0* South 5 2.4 0.48 3.02 1.64 4.8 10.0* South 6 0.6 0.79 3.02 0.25 4.5 10.0* South 7 0.5 0.79 3.02 0.19 3.5 10.0* South 8 0.6 0.79 3.02 0.27 3.0 10.0* North 1 0.7 0.30 3.02 0.73 7.3 10.0* North 2 0.3 0.30 3.02 0.30 4.0 10.0* North 3 0.3 0.30 3.02 0.31 3.2 10.0* *Some computed Tc values reduced to a maximum value of 1 hour

Summary Table for 5-Year event:

Rational Rainfall Time of Time of Subbasin ID Discharge Coeff. Intensity Area Concentration Concentration Q C i A Computed Tc Applied Tc (cfs) (inches/hour) (acres) (minutes) (minutes) South 1 35.8 0.48 4.01 18.59 5.1 10.0* South 2 8.0 0.48 4.01 4.14 4.2 10.0* South 3 3.5 0.41 4.01 2.14 5.4 10.0* South 4 7.2 0.48 4.01 3.74 6.9 10.0* South 5 3.7 0.56 4.01 1.64 4.3 10.0*

South 6 0.8 0.84 4.01 0.25 4.0 10.0* South 7 0.6 0.84 4.01 0.19 3.2 10.0* South 8 0.9 0.84 4.01 0.27 2.7 10.0* North 1 1.2 0.41 4.01 0.73 6.4 10.0* North 2 0.5 0.41 4.01 0.30 3.6 10.0* North 3 0.5 0.41 4.01 0.31 2.9 10.0* *Some computed Tc values reduced to a maximum value of 1 hour

Summary Table for 10-Year event:

Rational Rainfall Time of Time of Subbasin ID Discharge Coeff. Intensity Area Concentration Concentration Q C i A Computed Tc Applied Tc (cfs) (inches/hour) (acres) (minutes) (minutes) South 1 46.9 0.53 4.76 18.59 4.8 10.0* South 2 10.5 0.53 4.76 4.14 3.9 10.0* South 3 4.7 0.46 4.76 2.14 5.0 10.0* South 4 9.4 0.53 4.76 3.74 6.4 10.0* South 5 4.8 0.61 4.76 1.64 4.0 10.0* South 6 1.0 0.87 4.76 0.25 3.7 10.0* South 7 0.8 0.87 4.76 0.19 2.9 10.0* South 8 1.1 0.87 4.76 0.27 2.5 10.0* North 1 1.6 0.46 4.76 0.73 5.9 10.0* North 2 0.7 0.46 4.76 0.30 3.3 10.0* North 3 0.7 0.46 4.76 0.31 2.7 10.0* *Some computed Tc values reduced to a maximum value of 1 hour

Summary Table for 25-Year event:

Rational Rainfall Time of Time of Subbasin ID Discharge Coeff. Intensity Area Concentration Concentration Q C i A Computed Tc Applied Tc (cfs) (inches/hour) (acres) (minutes) (minutes) South 1 63.5 0.59 5.79 18.59 4.4 10.0* South 2 14.1 0.59 5.79 4.14 3.6 10.0* South 3 6.4 0.52 5.79 2.14 4.6 10.0* South 4 12.8 0.59 5.79 3.74 5.8 10.0* South 5 6.4 0.67 5.79 1.64 3.7 10.0* South 6 1.3 0.91 5.79 0.25 3.4 10.0* South 7 1.0 0.91 5.79 0.19 2.7 10.0* South 8 1.4 0.91 5.79 0.27 2.3 10.0* North 1 2.2 0.52 5.79 0.73 5.4 10.0* North 2 0.9 0.52 5.79 0.30 3.1 10.0* North 3 0.9 0.52 5.79 0.31 2.5 10.0*

*Some computed Tc values reduced to a maximum value of 1 hour

Summary Table for 50-Year event:

Rational Rainfall Time of Time of Subbasin ID Discharge Coeff. Intensity Area Concentration Concentration Q C i A Computed Tc Applied Tc (cfs) (inches/hour) (acres) (minutes) (minutes) South 1 76.0 0.62 6.59 18.59 4.2 10.0* South 2 16.9 0.62 6.60 4.14 3.4 10.0* South 3 7.9 0.56 6.60 2.14 4.4 10.0* South 4 15.3 0.62 6.60 3.74 5.5 10.0* South 5 7.6 0.70 6.60 1.64 3.5 10.0* South 6 1.5 0.93 6.60 0.25 3.3 10.0* South 7 1.2 0.93 6.60 0.19 2.6 10.0* South 8 1.6 0.93 6.60 0.27 2.2 10.0* North 1 2.7 0.56 6.60 0.73 5.2 10.0* North 2 1.1 0.56 6.60 0.30 2.9 10.0* North 3 1.2 0.56 6.60 0.31 2.4 10.0* *Some computed Tc values reduced to a maximum value of 1 hour

Summary Table for 100-Year event:

Rational Rainfall Time of Time of Subbasin ID Discharge Coeff. Intensity Area Concentration Concentration Q C i A Computed Tc Applied Tc (cfs) (inches/hour) (acres) (minutes) (minutes) South 1 90.0 0.65 7.45 18.59 3.9 10.0* South 2 20.0 0.65 7.44 4.14 3.2 10.0* South 3 9.4 0.59 7.44 2.14 4.1 10.0* South 4 18.1 0.65 7.44 3.74 5.2 10.0* South 5 8.9 0.73 7.44 1.64 3.3 10.0* South 6 1.7 0.94 7.44 0.25 3.1 10.0* South 7 1.3 0.94 7.44 0.19 2.5 10.0* South 8 1.9 0.94 7.44 0.27 2.1 10.0* North 1 3.2 0.59 7.44 0.73 4.9 10.0* North 2 1.3 0.59 7.44 0.30 2.8 10.0* North 3 1.4 0.59 7.44 0.31 2.3 10.0* *Some computed Tc values reduced to a maximum value of 1 hour

Appendix C: Existing Conditions Modeling

Results

Existing Conditions HY-8 Culvert Analysis Report

Crossing Discharge Data

Discharge Selection Method: Specify Minimum, Design, and Maximum Flow

Minimum Flow: 27.40 cfs

Design Flow: 77.60 cfs

Maximum Flow: 110.00 cfs

Table 1 - Summary of Culvert Flows at Crossing: Existing 107+83 (SC2)

Headwater Elevation (ft)

Total Discharge (cfs)

Existing SC2 Discharge (cfs)

Roadway Discharge (cfs)

Iterations

6349.05 27.40 11.35 15.87 9

6349.10 35.66 11.46 24.00 4

6349.14 43.92 11.56 32.26 4

6349.17 52.18 11.65 40.48 4

6349.21 60.44 11.73 48.52 3

6349.24 68.70 11.81 56.76 3

6349.27 77.60 11.89 65.63 3

6349.30 85.22 11.95 73.23 3

6349.33 93.48 12.02 81.44 3

6349.35 101.74 12.08 89.42 2

6349.38 110.00 12.15 97.56 2

6348.91 10.97 10.97 0.00 Overtopping

Culvert Data: Existing SC2

Table 2 - Culvert Summary Table: Existing SC2

Total Disch arge (cfs)

Culve rt Disch arge (cfs)

Head water Elevat ion (ft)

Inle t Con trol Dep th (ft)

Outl et Con trol Dep th (ft)

Fl ow Ty pe

Nor mal Dep th (ft)

Crit ical 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)

27.40 cfs

11.35 cfs

6349.0

3.14 2.88

7- M2 c

1.50 1.29 1.2

0.58 7.04 4.74

35.66 cfs

11.46 cfs

6349.1

3.19 2.94

7- M2 c

1.50 1.29 1.2

0.68 7.08 5.23

43.92 cfs

11.56 cfs

6349.1

3.23 3.00

7- M2 c

1.50 1.30 1.3

0.78 7.12 5.65

52.18 cfs

11.65 cfs

6349.1

3.26 3.05

7- M2 c

1.50 1.30 1.3

0.87 7.16 6.01

60.44 cfs

11.73 cfs

6349.2

3.30 3.10

7- M2 c

1.50 1.30 1.3

0.95 7.20 6.34

68.70 cfs

11.81 cfs

6349.2

3.33 3.14

7- M2 c

1.50 1.31 1.3

1.03 7.23 6.64

77.60 cfs

11.89 cfs

6349.2

3.36 3.18

7- M2 c

1.50 1.31 1.3

1.12 7.26 6.93

85.22 cfs

11.95 cfs

6349.3

3.39 3.22

7- M2 c

1.50 1.31 1.3

1.19 7.29 7.16

93.48 cfs

12.02 cfs

6349.3

3.42 3.25

7- M2 c

1.50 1.31 1.3

1.26 7.32 7.40

101.7 4 cfs

12.08 cfs

6349.3

3.44 3.28

7- M2 t

1.50 1.32 1.3

1.34 7.27 7.62

110.0 0 cfs

12.15 cfs

6349.3

3.47 3.34

7- M2 t

1.50 1.32 1.4

1.41 7.06 7.82

Culvert Barrel Data

Culvert Barrel Type Straight Culvert

Inlet Elevation (invert): 6345.91 ft, Outlet Elevation (invert): 6344.85 ft

Culvert Length: 35.02 ft, Culvert Slope: 0.0303

Site Data - Existing SC2

Site Data Option: Culvert Invert Data

Inlet Station: 0.00 ft

Inlet Elevation: 6345.91 ft

Outlet Station: 35.00 ft

Outlet Elevation: 6344.85 ft

Number of Barrels: 1

Culvert Data Summary - Existing SC2

Barrel Shape: Circular

Barrel Diameter: 1.50 ft

Barrel Material: Corrugated Steel

Embedment: 0.00 in

Barrel Manning's n: 0.0240

Culvert Type: Straight

Inlet Configuration: Thin Edge Projecting

Inlet Depression: None

Tailwater Data for Crossing: Existing 107+83 (SC2)

Table 3 - Downstream Channel Rating Curve (Crossing: Existing 107+83 (SC2))

Flow (cfs) Water Surface Elev (ft)

Velocity (ft/s)

Depth (ft) Shear (psf) Froude Number

27.40 6345.43 0.58 4.74 1.08 1.10

35.66 6345.53 0.68 5.23 1.28 1.12

43.92 6345.63 0.78 5.65 1.46 1.13

52.18 6345.72 0.87 6.01 1.62 1.14

60.44 6345.80 0.95 6.34 1.78 1.14

68.70 6345.88 1.03 6.64 1.94 1.15

77.60 6345.97 1.12 6.93 2.10 1.15

85.22 6346.04 1.19 7.16 2.23 1.16

93.48 6346.11 1.26 7.40 2.37 1.16

101.74 6346.19 1.34 7.62 2.50 1.16

110.00 6346.26 1.41 7.82 2.63 1.16

Tailwater Channel Data - Existing 107+83 (SC2)

Tailwater Channel Option: Rectangular Channel

Bottom Width: 10.00 ft

Channel Slope: 0.0300

Channel Manning's n: 0.0350

Channel Invert Elevation: 6344.85 ft

Roadway Data for Crossing: Existing 107+83 (SC2)

Roadway Profile Shape: Constant Roadway Elevation

Crest Length: 100.00 ft

Crest Elevation: 6348.91 ft

Roadway Surface: Paved

Roadway Top Width: 26.00 ft

Crossing Discharge Data

Discharge Selection Method: Specify Minimum, Design, and Maximum Flow

Minimum Flow: 10.50 cfs

Design Flow: 14.10 cfs

Maximum Flow: 20.00 cfs

Table 4 - Summary of Culvert Flows at Crossing: Existing 109+53 (SD4)

Headwater Elevation (ft)

Total Discharge (cfs)

Existing SD4 Discharge (cfs)

Roadway Discharge (cfs)

Iterations

6351.00 10.50 2.39 8.05 8

6351.01 11.45 2.42 9.01 3

6351.01 12.40 2.44 9.94 3

6351.02 13.35 2.47 10.76 2

6351.03 14.10 2.49 11.59 3

6351.03 15.25 2.52 12.62 2

6351.04 16.20 2.54 13.50 2

6351.04 17.15 2.57 14.57 3

6351.05 18.10 2.60 15.46 2

6351.06 19.05 2.62 16.36 2

6351.06 20.00 2.64 17.29 2

6350.91 2.01 2.01 0.00 Overtopping

Culvert Data: Existing SD4

Table 5 - Culvert Summary Table: Existing SD4

Total Disch arge (cfs)

Culve rt Disch arge (cfs)

Head water Elevat ion (ft)

Inle t Con trol Dep th (ft)

Outl et Con trol Dep th (ft)

Fl ow Ty pe

Nor mal Dep th (ft)

Crit ical 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)

10.50

2.39 cfs

6351.0

0.82 1.02

2- M2 c

1.21 0.58 0.5

0.32 3.74 3.29

11.45 cfs

2.42 cfs

6351.0

0.82 1.02

2- M2 c

1.23 0.59 0.5

0.34 3.76 3.40

12.40 cfs

2.44 cfs

6351.0

0.83 1.03

2- M2 c

1.24 0.59 0.5

0.35 3.77 3.51

13.35 cfs

2.47 cfs

6351.0

0.83 1.04

2- M2 c

1.26 0.59 0.5

0.37 3.78 3.61

14.10 cfs

2.49 cfs

6351.0

0.84 1.04

2- M2 c

1.27 0.60 0.6

0.38 3.79 3.69

15.25 cfs

2.52 cfs

6351.0

0.84 1.05

2- M2 c

1.30 0.60 0.6

0.40 3.81 3.80

16.20 cfs

2.54 cfs

6351.0

0.85 1.05

2- M2 c

1.31 0.60 0.6

0.42 3.82 3.89

17.15 cfs

2.57 cfs

6351.0

0.85 1.06

2- M2 c

1.35 0.61 0.6

0.43 3.83 3.97

18.10 cfs

2.60 cfs

6351.0

0.86 1.07

2- M2 c

1.50 0.61 0.6

0.45 3.84 4.06

19.05 cfs

2.62 cfs

6351.0

0.86 1.07

2- M2 c

1.50 0.61 0.6

0.46 3.85 4.14

20.00 cfs

2.64 cfs

6351.0

0.87 1.08

2- M2 c

1.50 0.62 0.6

0.47 3.86 4.21

Culvert Barrel Data

Culvert Barrel Type Straight Culvert

Inlet Elevation (invert): 6349.98 ft, Outlet Elevation (invert): 6349.89 ft

Culvert Length: 50.00 ft, Culvert Slope: 0.0018

Site Data - Existing SD4

Site Data Option: Culvert Invert Data

Inlet Station: 0.00 ft

Inlet Elevation: 6349.98 ft

Outlet Station: 50.00 ft

Outlet Elevation: 6349.89 ft

Number of Barrels: 1

Culvert Data Summary - Existing SD4

Barrel Shape: Circular

Barrel Diameter: 1.50 ft

Barrel Material: Corrugated Steel

Embedment: 0.00 in

Barrel Manning's n: 0.0240

Culvert Type: Straight

Inlet Configuration: Square Edge with Headwall

Inlet Depression: None

Tailwater Data for Crossing: Existing 109+53 (SD4)

Table 6 - Downstream Channel Rating Curve (Crossing: Existing 109+53 (SD4))

Flow (cfs) Water Surface Elev (ft)

Velocity (ft/s)

Depth (ft) Shear (psf) Froude Number

10.50 6350.21 0.32 3.29 0.60 1.03

11.45 6350.23 0.34 3.40 0.63 1.03

12.40 6350.24 0.35 3.51 0.66 1.04

13.35 6350.26 0.37 3.61 0.69 1.05

14.10 6350.27 0.38 3.69 0.72 1.05

15.25 6350.29 0.40 3.80 0.75 1.06

16.20 6350.31 0.42 3.89 0.78 1.06

17.15 6350.32 0.43 3.97 0.81 1.07

18.10 6350.34 0.45 4.06 0.84 1.07

19.05 6350.35 0.46 4.14 0.86 1.07

20.00 6350.36 0.47 4.21 0.89 1.08

Tailwater Channel Data - Existing 109+53 (SD4)

Tailwater Channel Option: Rectangular Channel

Bottom Width: 10.00 ft

Channel Slope: 0.0300

Channel Invert Elevation: 6349.89 ft

Roadway Data for Crossing: Existing 109+53 (SD4)

Roadway Profile Shape: Constant Roadway Elevation

Crest Length: 100.00 ft

Crest Elevation: 6350.91 ft

Roadway Surface: Paved

Roadway Top Width: 13.00 ft

Crossing Discharge Data

Discharge Selection Method: Specify Minimum, Design, and Maximum Flow

Minimum Flow: 4.70 cfs

Design Flow: 6.40 cfs

Maximum Flow: 9.40 cfs

Table 7 - Summary of Culvert Flows at Crossing: Existing 112+53 (SC5)

Headwater Elevation (ft)

Total Discharge (cfs)

Existing SC5 Discharge (cfs)

Roadway Discharge (cfs)

Iterations

6365.93 4.70 2.51 2.17 9

6365.93 5.17 2.53 2.61 3

6365.94 5.64 2.54 3.08 3

6365.94 6.11 2.55 3.54 3

6365.94 6.40 2.55 3.78 2

6365.95 7.05 2.57 4.46 3

6365.96 7.52 2.58 4.87 2

6365.96 7.99 2.59 5.39 3

6365.96 8.46 2.60 5.81 2

6365.97 8.93 2.60 6.25 2

6365.97 9.40 2.61 6.69 2

6365.89 2.42 2.42 0.00 Overtopping

Culvert Data: Existing SC5

Table 8 - Culvert Summary Table: Existing SC5

Total Disch arge (cfs)

Culve rt Disch

Head water Elevat

Inle t Con trol

Outl et Con trol

Fl ow Ty pe

Nor mal Dep

Crit ical Dep

Out let De

Tailw ater Dept h (ft)

Outl et Velo city

Tailw ater Veloc arge (cfs) ion (ft)

Dep th (ft)

Dep th (ft) th (ft) th (ft) pth (ft)

(ft/s ity (ft/s)

4.70 cfs

2.51 cfs

6365.9

1.17 0.0* 5- S2 n

0.48 0.68 0.4

0.19 6.81 2.41

5.17 cfs

2.53 cfs

6365.9

1.17 0.0* 5- S2 n

0.48 0.68 0.4

0.21 6.82 2.50

5.64 cfs

2.54 cfs

6365.9

1.18 0.0* 5- S2 n

0.48 0.68 0.4

0.22 6.82 2.59

6.11 cfs

2.55 cfs

6365.9

1.18 0.0* 5- S2 n

0.48 0.68 0.4

0.23 6.83 2.67

6.40 cfs

2.55 cfs

6365.9

1.18 0.0* 5- S2 n

0.48 0.68 0.4

0.24 6.84 2.72

7.05 cfs

2.57 cfs

6365.9

1.19 0.0* 5- S2 n

0.48 0.69 0.4

0.25 6.85 2.82

7.52 cfs

2.58 cfs

6365.9

1.20 0.0* 5- S2 n

0.48 0.69 0.4

0.26 6.85 2.89

7.99 cfs

2.59 cfs

6365.9

1.20 0.0* 5- S2 n

0.48 0.69 0.4

0.27 6.86 2.96

8.46 cfs

2.60 cfs

6365.9

1.20 0.0* 5- S2 n

0.49 0.69 0.4

0.28 6.86 3.03

8.93 cfs

2.60 cfs

6365.9

1.21 0.0* 5- S2 n

0.49 0.69 0.4

0.29 6.87 3.09

9.40 cfs

2.61 cfs

6365.9

1.21 0.0* 5- S2 n

0.49 0.69 0.4

0.30 6.87 3.16

* Full Flow Headwater elevation is below inlet invert.

Culvert Barrel Data

Culvert Barrel Type Straight Culvert

Inlet Elevation (invert): 6364.76 ft, Outlet Elevation (invert): 6362.29 ft

Culvert Length: 31.10 ft, Culvert Slope: 0.0797

Site Data - Existing SC5

Inlet Station: 0.00 ft

Inlet Elevation: 6364.76 ft

Outlet Station: 31.00 ft

Outlet Elevation: 6362.29 ft

Number of Barrels: 1

Culvert Data Summary - Existing SC5

Barrel Shape: Circular

Barrel Diameter: 1.00 ft

Barrel Material: Corrugated Steel

Embedment: 0.00 in

Barrel Manning's n: 0.0240

Culvert Type: Straight

Inlet Configuration: Thin Edge Projecting

Inlet Depression: None

Tailwater Data for Crossing: Existing 112+53 (SC5)

Table 9 - Downstream Channel Rating Curve (Crossing: Existing 112+53 (SC5))

Flow (cfs) Water Surface Elev (ft)

Velocity (ft/s)

Depth (ft) Shear (psf) Froude Number

4.70 6362.48 0.19 2.41 0.36 0.96

5.17 6362.50 0.21 2.50 0.39 0.97

5.64 6362.51 0.22 2.59 0.41 0.98

6.11 6362.52 0.23 2.67 0.43 0.98

6.40 6362.53 0.24 2.72 0.44 0.99

7.05 6362.54 0.25 2.82 0.47 1.00

7.52 6362.55 0.26 2.89 0.49 1.00

7.99 6362.56 0.27 2.96 0.50 1.01

8.46 6362.57 0.28 3.03 0.52 1.01

8.93 6362.58 0.29 3.09 0.54 1.01

9.40 6362.59 0.30 3.16 0.56 1.02

Tailwater Channel Data - Existing 112+53 (SC5)

Tailwater Channel Option: Rectangular Channel

Bottom Width: 10.00 ft

Channel Slope: 0.0300

Channel Manning's n: 0.0350

Channel Invert Elevation: 6362.29 ft

Roadway Data for Crossing: Existing 112+53 (SC5)

Roadway Profile Shape: Constant Roadway Elevation

Crest Length: 100.00 ft

Crest Elevation: 6365.89 ft

Roadway Surface: Paved

Roadway Top Width: 26.00 ft

Crossing Discharge Data

Discharge Selection Method: Specify Minimum, Design, and Maximum Flow

Minimum Flow: 9.40 cfs

Design Flow: 12.80 cfs

Maximum Flow: 18.10 cfs

Table 10 - Summary of Culvert Flows at Crossing: Existing 122+20 (NC1)

Headwater Elevation (ft)

Total Discharge (cfs)

Existing NC1 Discharge (cfs)

Roadway Discharge (cfs)

Iterations

6363.93 9.40 9.40 0.00 1

6364.38 10.27 10.27 0.00 1

6364.84 11.14 11.14 0.00 1

6365.34 12.01 12.01 0.00 1

6365.82 12.80 12.80 0.00 1

6366.43 13.75 13.75 0.00 1

6367.02 14.62 14.62 0.00 1

6367.22 15.49 14.91 0.50 26

6367.24 16.36 14.93 1.32 4

6367.25 17.23 14.94 2.22 4

6367.26 18.10 14.96 3.03 3

6367.21 14.89 14.89 0.00 Overtopping

Culvert Data: Existing NC1

Table 11 - Culvert Summary Table: Existing NC1

Total Disch arge (cfs)

Culve rt Disch arge (cfs)

Head water Elevat ion (ft)

Inle t Con trol Dep th (ft)

Outl et Con trol Dep th (ft)

Fl ow Ty pe

Nor mal Dep th (ft)

Crit ical 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)

9.40 cfs

9.40 cfs

6363.9

2.47 2.85

7- M2 c

1.50 1.18 1.1

0.30 6.28 3.16

10.27 cfs

10.27 cfs

6364.3

2.76 3.29

7- M2 c

1.50 1.23 1.2

0.31 6.61 3.27

11.14 cfs

11.14 cfs

6364.8

3.08 3.76

7- M2 c

1.50 1.28 1.2

0.33 6.95 3.37

12.01 cfs

12.01 cfs

6365.3

3.43 4.25

7- M2 c

1.50 1.31 1.3

0.35 7.32 3.47

12.80 cfs

12.80 cfs

6365.8

3.77 4.73

7- M2 c

1.50 1.34 1.3

0.36 7.67 3.55

13.75 cfs

13.75 cfs

6366.4

4.23 5.34

7- M2 c

1.50 1.37 1.3

0.38 8.11 3.65

14.62 cfs

14.62 cfs

6367.0

4.68 5.93

7- M2 c

1.50 1.40 1.4

0.39 8.53 3.74

15.49 cfs

14.91 cfs

6367.2

4.83 6.14

7- M2 c

1.50 1.40 1.4

0.41 8.67 3.82

16.36 cfs

14.93 cfs

6367.2

4.85 6.15

7- M2 c

1.50 1.40 1.4

0.42 8.68 3.90

17.23 cfs

14.94 cfs

6367.2

4.85 6.17

7- M2 c

1.50 1.40 1.4

0.43 8.69 3.98

18.10 cfs

14.96 cfs

6367.2

4.86 6.17

7- M2 c

1.50 1.40 1.4

0.45 8.70 4.06

Culvert Barrel Data

Culvert Barrel Type Straight Culvert

Inlet Elevation (invert): 6361.08 ft, Outlet Elevation (invert): 6360.52 ft

Culvert Length: 46.00 ft, Culvert Slope: 0.0122

Site Data - Existing NC1

Site Data Option: Culvert Invert Data

Inlet Station: 0.00 ft

Inlet Elevation: 6361.08 ft

Outlet Station: 46.00 ft

Outlet Elevation: 6360.52 ft

Number of Barrels: 1

Culvert Data Summary - Existing NC1

Barrel Shape: Circular

Barrel Diameter: 1.50 ft

Barrel Material: Corrugated Steel

Embedment: 0.00 in

Barrel Manning's n: 0.0240

Culvert Type: Straight

Inlet Configuration: Thin Edge Projecting

Inlet Depression: None

Tailwater Data for Crossing: Existing 122+20 (NC1)

Table 12 - Downstream Channel Rating Curve (Crossing: Existing 122+20 (NC1))

Flow (cfs) Water Surface Elev (ft)

Velocity (ft/s)

Depth (ft) Shear (psf) Froude Number

9.40 6360.82 0.30 3.16 0.56 1.02

10.27 6360.83 0.31 3.27 0.59 1.03

11.14 6360.85 0.33 3.37 0.62 1.03

12.01 6360.87 0.35 3.47 0.65 1.04

12.80 6360.88 0.36 3.55 0.67 1.04

13.75 6360.90 0.38 3.65 0.70 1.05

14.62 6360.91 0.39 3.74 0.73 1.05

15.49 6360.93 0.41 3.82 0.76 1.06

16.36 6360.94 0.42 3.90 0.78 1.06

17.23 6360.95 0.43 3.98 0.81 1.07

18.10 6360.97 0.45 4.06 0.84 1.07

Tailwater Channel Data - Existing 122+20 (NC1)

Tailwater Channel Option: Rectangular Channel

Bottom Width: 10.00 ft

Channel Slope: 0.0300

Channel Manning's n: 0.0350

Channel Invert Elevation: 6360.52 ft

Roadway Data for Crossing: Existing 122+20 (NC1)

Roadway Profile Shape: Constant Roadway Elevation

Crest Length: 100.00 ft

Crest Elevation: 6367.21 ft

Roadway Surface: Paved

Roadway Top Width: 26.00 ft

Crossing Discharge Data

Discharge Selection Method: Specify Minimum, Design, and Maximum Flow

Minimum Flow: 4.80 cfs

Design Flow: 6.40 cfs

Maximum Flow: 8.90 cfs

Table 13 - Summary of Culvert Flows at Crossing: Existing 126+46 (NC2)

Headwater Elevation (ft)

Total Discharge (cfs)

Existing NC2 Discharge (cfs)

Roadway Discharge (cfs)

Iterations

6349.90 4.80 4.80 0.00 1

6349.99 5.21 5.21 0.00 1

6350.10 5.62 5.62 0.00 1

6350.22 6.03 6.03 0.00 1

6350.39 6.40 6.40 0.00 1

6350.56 6.85 6.85 0.00 1

6350.75 7.26 7.26 0.00 1

6350.93 7.67 7.67 0.00 1

6351.13 8.08 8.08 0.00 1

6351.24 8.49 8.29 0.11 26

6351.24 8.90 8.31 0.51 4

6351.23 8.28 8.28 0.00 Overtopping

Culvert Data: Existing NC2

Table 14 - Culvert Summary Table: Existing NC2

Total Disch arge (cfs)

Culve rt Disch arge (cfs)

Head water Elevat ion (ft)

Inle t Con trol Dep th (ft)

Outl et Con trol Dep th (ft)

Fl ow Ty pe

Nor mal Dep th (ft)

Crit ical 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)

4.80 cfs

4.80 cfs

6349.9

1.36 1.51

7- M2 c

1.50 0.84 0.8

0.20 4.70 2.43

5.21 cfs

5.21 cfs

6349.9

1.44 1.61

7- M2 c

1.50 0.88 0.8

0.21 4.84 2.51

5.62 cfs

5.62 cfs

6350.1

1.52 1.71

7- M2 c

1.50 0.91 0.9

0.22 4.98 2.58

6.03 cfs

6.03 cfs

6350.2

1.61 1.84

7- M2 c

1.50 0.95 0.9

0.23 5.12 2.66

6.40 cfs

6.40 cfs

6350.3

1.69 2.01

7- M2 c

1.50 0.98 0.9

0.24 5.24 2.72

6.85 cfs

6.85 cfs

6350.5

1.79 2.18

7- M2 c

1.50 1.01 1.0

0.25 5.40 2.79

7.26 cfs

7.26 cfs

6350.7

1.89 2.36

7- M2 c

1.50 1.04 1.0

0.25 5.53 2.86

7.67 cfs

7.67 cfs

6350.9

1.99 2.55

7- M2 c

1.50 1.07 1.0

0.26 5.67 2.92

8.08 cfs

8.08 cfs

6351.1

2.09 2.75

7- M2 c

1.50 1.10 1.1

0.27 5.81 2.98

8.49 cfs

8.29 cfs

6351.2

2.15 2.85

7- M2 c

1.50 1.12 1.1

0.28 5.89 3.03

8.90 cfs

8.31 cfs

6351.2

2.16 2.86

7- M2 c

1.50 1.12 1.1

0.29 5.89 3.09

Culvert Barrel Data

Inlet Elevation (invert): 6348.38 ft, Outlet Elevation (invert): 6348.07 ft

Culvert Length: 58.00 ft, Culvert Slope: 0.0053

Site Data - Existing NC2

Site Data Option: Culvert Invert Data

Inlet Station: 0.00 ft

Inlet Elevation: 6348.38 ft

Outlet Station: 58.00 ft

Outlet Elevation: 6348.07 ft

Number of Barrels: 1

Culvert Data Summary - Existing NC2

Barrel Shape: Circular

Barrel Diameter: 1.50 ft

Barrel Material: Corrugated Steel

Embedment: 0.00 in

Barrel Manning's n: 0.0240

Culvert Type: Straight

Inlet Configuration: Thin Edge Projecting

Inlet Depression: None

Tailwater Data for Crossing: Existing 126+46 (NC2)

Table 15 - Downstream Channel Rating Curve (Crossing: Existing 126+46 (NC2))

Flow (cfs) Water Surface Elev (ft)

Velocity (ft/s)

Depth (ft) Shear (psf) Froude Number

4.80 6348.27 0.20 2.43 0.37 0.96

5.21 6348.28 0.21 2.51 0.39 0.97

5.62 6348.29 0.22 2.58 0.41 0.98

6.03 6348.30 0.23 2.66 0.42 0.98

6.40 6348.31 0.24 2.72 0.44 0.99

6.85 6348.32 0.25 2.79 0.46 0.99

7.26 6348.32 0.25 2.86 0.48 1.00

7.67 6348.33 0.26 2.92 0.49 1.00

8.08 6348.34 0.27 2.98 0.51 1.01

8.49 6348.35 0.28 3.03 0.52 1.01

8.90 6348.36 0.29 3.09 0.54 1.01

Tailwater Channel Data - Existing 126+46 (NC2)

Tailwater Channel Option: Rectangular Channel

Bottom Width: 10.00 ft

Channel Slope: 0.0300

Channel Manning's n: 0.0350

Channel Invert Elevation: 6348.07 ft

Roadway Data for Crossing: Existing 126+46 (NC2)

Roadway Profile Shape: Constant Roadway Elevation

Crest Length: 100.00 ft

Crest Elevation: 6351.23 ft

Roadway Surface: Paved

Roadway Top Width: 26.00 ft

Crossing Discharge Data

Discharge Selection Method: Specify Minimum, Design, and Maximum Flow

Minimum Flow: 1.00 cfs

Design Flow: 1.30 cfs

Maximum Flow: 1.70 cfs

Table 16 - Summary of Culvert Flows at Crossing: Existing 129+85 (NC4)

Headwater Elevation (ft)

Total Discharge (cfs)

Existing NC4 Discharge (cfs)

Roadway Discharge (cfs)

Iterations

6343.00 1.00 1.00 0.00 1

6343.02 1.07 1.07 0.00 1

6343.04 1.14 1.14 0.00 1

6343.06 1.21 1.21 0.00 1

6343.09 1.30 1.30 0.00 1

6343.10 1.35 1.35 0.00 1

6343.12 1.42 1.42 0.00 1

6343.14 1.49 1.49 0.00 1

6343.16 1.56 1.56 0.00 1

6343.18 1.63 1.63 0.00 1

6343.19 1.70 1.70 0.00 1

6346.39 10.64 10.64 0.00 Overtopping

Culvert Data: Existing NC4

Table 17 - Culvert Summary Table: Existing NC4

Total Disch arge (cfs)

Culve rt Disch arge (cfs)

Head water Elevat ion (ft)

Inle t Con trol Dep th (ft)

Outl et Con trol Dep th (ft)

Fl ow Ty pe

Nor mal Dep th (ft)

Crit ical 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)

1.00 cfs

1.00 cfs

6343.0

0.55 0.60

2- M2 c

0.48 0.37 0.3

0.08 2.92 1.31

1.07 cfs

1.07 cfs

6343.0

0.57 0.62

2- M2 c

0.50 0.39 0.3

0.08 2.97 1.35

1.14 cfs

1.14 cfs

6343.0

0.59 0.64

2- M2 c

0.52 0.40 0.4

0.08 3.03 1.38

1.21 cfs

1.21 cfs

6343.0

0.61 0.66

2- M2 c

0.53 0.41 0.4

0.09 3.08 1.41

1.30 cfs

1.30 cfs

6343.0

0.63 0.69

2- M2 c

0.55 0.43 0.4

0.09 3.14 1.45

1.35 cfs

1.35 cfs

6343.1

0.64 0.71

2- M2 c

0.57 0.44 0.4

0.09 3.17 1.48

1.42 cfs

1.42 cfs

6343.1

0.66 0.73

2- M2 c

0.58 0.45 0.4

0.09 3.22 1.51

1.49 cfs

1.49 cfs

6343.1

0.68 0.75

2- M2 c

0.60 0.46 0.4

0.10 3.26 1.54

1.56 cfs

1.56 cfs

6343.1

0.69 0.76

2- M2 c

0.61 0.47 0.4

0.10 3.31 1.56

1.63

1.63 cfs

6343.1

0.71 0.78

2- M2 c

0.63 0.48 0.4

0.10 3.35 1.59

1.70 cfs

1.70 cfs

6343.1

0.73 0.80

2- M2 c

0.64 0.49 0.4

0.11 3.39 1.62

Culvert Barrel Data

Culvert Barrel Type…