Hydraulic_Report RIMO.pdf

Hydraulic Report

Entrance Road and Parking Areas

Rio Mora National Wildlife Refuge

NM FTFW RIMO 10(1)

Federal Highway Administration

Central Federal Lands Highway Division

US Fish & Wildlife Service

Mora County, New Mexico

August 7, 2020

August 7, 2020 | i

Table of Contents

Executive Summary

1 Introduction

2 Drainage Basins

3 Drainage Design Assumptions

4 Culverts

4.1 Hydraulic Design Standards and Methods for Culverts

4.2 Culvert Analysis and Results

5 Ditches

5.1 Roadway Hydraulics

5.2 Hydraulic Design Standards and Methods

5.3 Hydraulic Analysis and Results

6 Outlet Protection

7 References

Tables

Table 1 Peak discharge calculations for a 25 year storm event using TR-55 method ……… ................…..4

Table 2 Culverts Design Criteria

Table 3 – Culverts Summary

Table 4 – Design Criteria for Ditches

Figures

Figure 1 – Project Location – Rio Mora National Wildlife Refuge in Mora County, NM

Figure 2 – Site Photos of the Culvert Channel Bottom (Outlet Left, Inlet Right)

Figure 3 – Table 3-4 of FHWA Urban Drainage Design Manual

Figure 4 – Site Photos of Channel Bottom for Ditches

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Executive Summary

The proposed project is the rehabilitation of the existing Rio Mora National Wildlife Refuge (RIMO) main entrance road from New Mexico 161 (NM161), administration parking area, Thaw lodge parking area, bunkhouse parking area, environmental education parking area, and additional roads to these parking areas. It is located in Mora County, northwest of Interstate 25, in northern New

Mexico. All existing vehicular access roadway surfaces are gravel, native soil, or a combination of the two. The main entrance road length is approximately 1.58 miles and mostly two-way roadway with a graveled width of 18 to 22 feet. This Hydraulic Report provides a summary of the hydraulic and hydrologic analysis of the existing drainage impacting the project and the drainage conveyance design for proposed improvements.

During large storm events, the existing stock pond overflows around the existing embankment adjacent to the roadway and causes erosion and washout of the roadway and downstream channel.

Four (4) 24 inch diameter culverts have been proposed to convey the 25 year design storm flow for this locaton without overflowing the road. A 20’ wide opening ditch is proposed from the stock pond bottom through berm toward the proposed culvert inlets location.

The profile of the proposed road was designed to mimic the horizontal alignment and vertical profile of the existing road to reduce the need for new ditches and stormwater management and reduce the overall ground disturbance and project costs. Pavement base course materials and subgrade at the low-water crossings will be protected from erosion with concrete barrier installed below the concrete pavement to mitigate soil erosion and prevent loss of roadway base materials during runoff events which exceed the design capacity of the four (4) 24 inch diameter culverts.

Other existing culverts within the project limits will remain, be extended, or be replaced with new culverts. All Existing culverts were analyzed to determine their capacity before overtopping and where necessary, new culverts were added to the project. To mitigate potential scour, riprap will be installed at the existing and proposed culvert outlets.

Roadside ditches are provided to match the existing conveyance as applicable. The capacity of the ditches was determined by comparing maximum flows the ditches can convey to a downstream culvert for the 10-year event contributing from the drainage sub-basin created by the ditches and roadway cross slope and profile. The existing upland section of the entrance road has limited ditches on either side of the roadway to allow overland dispersion of stormwater runoff without creating concentrated flow conditions. Overland dispersion is a preferred stormwater disposal method and was requested to be perpetuated by Refuge staff. On the narrow canyon descent roadway section there is a ditch on the uphill side of the roadway with culvert crossings out letting on the on the downhill side similar to existing conditions. The proposed canyon descent roadway design enhances the existing uphill side ditch with rock armoring to prevent erosion and loss of the roadway shoulder materials. Riprap and/or check dams will be required to mitigate erosion and reduce velocities where determined necessary.

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1 Introduction

The scope of work for this project is to perform engineering, surveying, hydraulic, and project management services towards delivery of a final set of plans, specifications and estimate for the Federal Highway Administration, Central Federal Lands Highway

Division (CFLHD) for proposed improvements to Rio Mora National Wildlife Refuge

Entrance Road and Visitor Center Parking Lots.

The existing two main roadways (10 AZ and 10 BZ) are varying width two-way gravel surface roadway with a width of 18 to 22 feet. 10AZ road is approximately 1.58 miles and

10BZ is approximately 0.3 miles in length which are located in Mora County, northwest of

Interstate 25, in northern New Mexico (Figure 1).

Rio Mora National Wildlife Refuge is currently closed to the public and only accessible by appointment. The proposed improvements to the access roads and parking areas are intended to improve car and bus accessibility for use by the public.

Figure 1 – Project Location – Rio Mora National Wildlife Refuge in Mora County, NM

The purpose of this Hydraulic Report is to provide a summary of the hydraulic analysis of the existing roadway and impoundment drainage, along with the proposed roadway and drainage improvements. Assessment of the existing drainage was performed to identify

Project Location

4 | August 7, 2020 conditions or performance problems and determine whether existing drainage structures and features would need to be replaced, rehabilitated, or modified (FLH, 2014). Design of the proposed drainage improvements includes replacing culverts, extending culverts, installing culvert outlet erosion protection, placing and armoring roadside ditches along the side of the roadway to convey runoff, and other safety-related features necessary to meet current design practice.

2 Drainage Basins

Five (5) drainage basins were identified along the length of the project requiring a hydraulic road crossing as identified in table 1. Appendix A exhibits the Basin delineations along with the drainage path. Following HEC-22 the time of concentration (Tc) was computed for the large sized basins. The NRCS TR-55

Method was used to determine the peak runoff hydrographs flowing to the Basins during the 2, 10, and 25, 100-year storm events. An NRCS Type II storm event is valid for this region of New Mexico. Storm depths were obtained from NOAA Atlas

14, Volume 1 for the 24-hour runoff depths (Appendix E).

Table 1: Peak discharge calculations for a 25 year storm event using TR-55 method

Basin ID Existing Culvert

Station

Area

(ac) q

(cfs)

Remarks

A 136+77 90.9 77.01 NRCS Method

B 159+25 8.1 7.94 NRCS Method

C 166+50 10.7 4.77 NRCS Method

D 173+72 32.0 10.69 NRCS Method

E 182+56 5.1 1.99 NRCS Method

3 Drainage Design Assumptions

The following assumptions were used to layout and design the proposed drainage system. These include:

1. The NRCS TR-55 Method was used to perform the calculations of peak discharge of the drainage Basins for the 2, 10, 25 and 100-year events which was used for analysis and design of the project culverts, based on the consistent ground cover and the basin sizes.

2. The 10-year design frequency is used for calculating flow rates for ditch.

3. All existing culverts that cross main roadway will remain or be extended, except the 18” culvert at 136+77 which would be removed and replaced with 4 of 24” culverts to be located at 136+46, 136+50, and 136+54, 136+58. Also the existing

24” culvert at 182+56 would be replaced in-kind. The capacity of the new and

August 7, 2020 | 5 existing culverts to remain were analyzed for capacity before overtopping the road.

4 Culverts

4.1 Hydraulic Design Standards and Methods for Culverts

Design Flood

According to Project Development and Design Manual (PDDM), culverts are to be designed based on the roadway classification. Since the roadway for this project is not a critical access road, it is classified as a low-standard road. Culverts for low-standard roads are designed to convey runoff from the 25-year flood without creating a headwater effect. Headwater elevation for existing culverts should not be greater than the edge of the paving improvements hinge point at the roadway low point (FLH, 2014).

Stability Design

The stability design flood standard refers to the ability of roadway culverts and embankments at culvert locations to be stable for the 25-year flood.

Design Criteria Summary

According to the PDDM, culverts are to be designed with the design criteria summarized in Table 1.

Table 2 – Culverts Design Criteria

Criteria Standard

Design Standards 25-year flood

Stability Design 25-year flood

Headwater

New: WSEL ≤ bottom of aggregate base layer Existing: WSEL ≤ shoulder hinge point.

HW/D ratio: 48” or smaller = 1.5 Larger than 48” = 1.2

Minimum Size Cross-road culvert = 24” Parallel culvert = 18”

Slope Stream Crossings: Match streambed Ditch Relief: Min. = 2%, Max. = 25% for metal pipes

4.2 Culvert Analysis and Results

For this project, four (4) new culverts are proposed at the low point of 10AZ road near the existing stock pond. Other existing culverts will be maintained or replaced with new culverts. Existing and new culverts were analyzed to determine their capacity before overtopping with HY8. Reports from HY8 are included in Appendix C. Manning’s

6 | August 7, 2020 roughness coefficients were assigned based on information gathered during the site inspection and Table 3-4 of FHWA Urban Drainage Design Manual to determine the appropriate coefficient. The channel bottoms were classified as a small open channel with bare soil and some vegetation. Manning’s ‘n’ values of 0.020 for channel and 0.024 for CMP were used for the design. Photos of the channel used as reference for determining the roughness coefficient are provided below in Figure 2, and a written description of the channel material is shown in Table 3-4 in Figure 3. The existing culverts capacity and characteristics are summarized in Table 3. Proposed culverts will require riprap at culvert outlets. See Section 6 of this report for outlet protection at the culverts.

Figure 2 – Site Photos of the Open Channel Bottom (Outlet Left, Inlet Right)

Figure 3 – Table 3-4 of FHWA Urban Drainage Design Manual

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On the east side of the roadway at station 136+50 there is a stock pond for livestock and wildlife in the Rio Mora National Wildlife. During large storm events the pond overflows the impoundment berm and causes erosion and washout of the roadway and downstream channel.

The drainage basin contributing to the existing stock pond is approximately 91 acres in size, and the maximum pond storage capacity is approximately 62,000 cubic feet. During small events runoff enters the pond and infiltrates or evaporates.

Four (4) 24 inch diameter culverts have been included at the roadway to convey the 25 year design storm flow without overflowing the road. A 20’ wide opening ditch is proposed from the stock pond bottom through berm toward the proposed culvert inlets location. Drainage basin runoff calculations are provided in Appendix B. HY-8 culvert capacity analysis reports are included in Appendix C.

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Table 3 – Culverts Summary

Station Design

Flow

(Basin

Discharge) cfs

Pipe

Material

Existing Condition Proposed Condition

Pipe

Dia.

HW Slope Length No of

Barrels

Flow

Capacity at

HW/D = 1.5

Roadway

Discharge

Control Pipe

Dia.

HW Slope Length No of

Barrels

Flow Capacity at HW/D = 1.5

Roadway

Discharge

Control

(ft) (ft) (%) (ft.) (Each) (cfs) (cfs) Inlet/

Outlet

(ft) (ft) (%) (ft.) (Each) (cfs) (cfs) Inlet/

Outlet

136+77 77.01 CMP 1.50 2.25 0.44 20.68 1 8.73 68.32 Inlet

136+50 77.01 CMP 2.00 3.00 2.20 57.0 4 84.86 0.00 Inlet

159+25 7.94 CMP 2.00 3.00 3.21 20.29 1 16.21 0.00 Inlet 2.00 3.00 3.21 23.00 1 16.23 0.00 Inlet

166+50 4.77 CMP 2.00 3.00 5.41 27.93 1 11.69 0.00 Inlet 2.00 3.00 5.41 28.05 1 11.73 0.00 Inlet

173+72 10.69 CMP 2.00 3.00 6.21 25.66 1 15.97 0.00 Inlet 2.00 3.00 6.21 26.05 1 15.96 0.00 Inlet

182+56 1.99 CMP 2.00 3.00 1.02 35.27 1 19.14 0.00 Outlet 2.00 3.00 1.14 37.00 1 19.15 0.00 Outlet

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5 Ditches

Roadsides within the upland portion of the access road will not have ditches and continue to allow overland dispersion of runoff from the roadway. The portion of the access road descending into the canyon will utilize existing ditch along the uphill side of the road to convey roadway runoff and contributing overland runoff from uphill slopes to cross culverts as at existing culvert locations. No new ditch will be graded as part of the roadway construction. However near the canyon descend landing, new ditch will be graded from 182+81 to 186+00 to convey roadway runoff and contributing overland runoff to the nearby culver location.

5.1 Roadway Hydraulics

The proposed ditches will generally match the existing ditch size, location and grade due to existing conditions and topography constraints. Areas of sedimentation and existing check dams were observed onsite within the ditch system. Existing ditches along the canyon descent section will be enhanced with riprap lining and culvert inlets will be re-graded to improve hydraulics.

5.2 Hydraulic Design Standards and Methods

Stability Design

According to PDDM, roadside ditches are to be designed for stability based on the 10-year design event for both High and Low-Standard roadways. Temporary linings will be needed to protect ditches from erosion. The ditches along the canyon descent section are proposing to be lined with riprap.

Design Criteria Summary

The design depth of new ditches is to be limited to a depth of 1-foot from the top of road surfacing to limit cut/excavation of the existing rock cut along the canyon descent section which will nearly match the existing ditch along this section of roadway. Depth of the ditch is defined as the allowable depth of flow relative to the ditch invert. Considering limited area with the presence of the rock cut, it was determined to use 1:2 slopes on both sides of the ditch. The design criteria for ditch is summarized in Table 4.

Table 4 – Design Criteria for Ditches

Criteria Standard

Capacity Design 10-year event

Stability Design 10-year event

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5.3 Hydraulic Analysis and Results

Since all basins for ditch design are smaller than 200 acres, time of concentration and

Rational Peak Flow Method described in FHWA Urban Drainage Design Manual was used to analyze ditch capacity. The roadside ditch capacities were analyzed for a 10 year event flow contributed from corresponding basins (Appendix B). Considering a ditch side slope 2:1 for the design event, the ditch flow appears to be supercritical in nature.

The depth of flow (super critical) varies in the range of 0.3’ to 0.5’ where the subcritical flow depth of the respective ditches varies in the range of 0.75’ to 1.35’. The analysis results are summarized in Appendix D.

Manning’s roughness coefficients were assigned based on examination of site photos and aerial image and using Tables 3-2 and 3-4 of FHWA Urban Drainage Design

Manual. Figure 4 shows existing conditions of the channel for ditch. The channel bottom for ditch is classified as a bare soil with some vegetation. Manning’s ‘n’ value for open channel flow is 0.023.

Figure 4 – Site Photos of Channel Bottom for Ditches

Intensity-duration-frequency curves based on precipitation frequency depths from NOAA

Atlas were used for value of rain intensity and are shown in Appendix E.

6 Outlet Protection

The culverts were analyzed for outlet protection for the design event. At the stock pond location the approximated 25-year exit flow rate of was assumed as 19.3 cfs through each of the 4 culvert barrels. Equation 10.4 from HEC-14 was used to calculate the resulting D50 for the riprap aprons. The calculated D50 sizes varied from 0.24 to 6.12 inch. Due to the project size and small quantity a single riprap size of Class 2 was selected for the project. Class 2 has an approximate D50 size of 6 inches. The gradation will provide adequate scour protection of the culverts installed on the project. HEC-14 calculations are provided in Appendix C.

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7 References

EPA. (2013, October 30). Water: Rivers & Streams . Retrieved from United States

Environmental Protection Agency:

https://archive.epa.gov/water/archive/web/html/streams.html

FLH. (2014, 12 29). Project Development and Design Manual (PDDM). Retrieved from USDOT, Federal Highway Administration: https://flh.fhwa.dot.gov/resources/design/pddm/

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Appendix A.

Drainage Basins

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Appendix B.

TR-55 Analyses

Note: Estimates the direct runoff using the NRCS Curve Number Method (HEC-22, Manual)

Project: Rio Mora NWR Project No: NM FTFW RIMO10(1)

Location: New Mexico Designer: Utpal Datta

HDR Engineering, Inc.

Return Frequency 24-Hour Precip

Depth (in) 100 4.52 50 4.01 25 3.53 10 2.92 5 2.49 2 1.96

From NOAA ATLAS 2, Volume 1

Project Sub-Basin Name A

Curve Number Area (ft2) CN x Area Grassland or Range 81 3,970,993 321,650,433

Total 3,970,993 321,650,433 Total Area (ac) 91.161 Weighted CN 81.00

SR 2.35

Basin Area 0.142439774 mi2

DIRECT RUNOFF BY THE NRCS PEAK FLOW METHOD

Pre-Development Post-Developed

Ia = 0.2SR : 0.469

Pre-Developed Post-Developed P Ia/P

(Calculated) Ia/P

(Selected)

100 Year 2.57 4.52 0.10 0.1

50 Year 2.13 4.01 0.12 25 Year 1.73 3.53 0.13 0.1 10 Year 1.25 2.92 0.16 0.1 5 Year 0.94 2.49 0.19 2 Year 0.58 1.96 0.24 0.3

PEAK OUTFLOW BY THE TABULAR HYDROGRAPH METHOD

Direct Runoff, QD (in)

Project Sub-Basin Name A

Basin Area: 0.142439774 mi2

ActualTravel Time: 0.38 QD QD QD QD QD QD QD

Selected Travel Time: 0.40 0.00 0.00 0.00 0.58 1.25 1.73 2.57

Time Unit Discharge

(csm/in) 2-Year Flow (cfs) 10-Year Flow

(cfs) 100-Year Flow

(cfs) 2-Year Flow

(cfs) 10-Year

Flow (cfs) 25-Year

Flow (cfs) 100-Year Flow (cfs)

9 18.00 1.485 3.211 4.443 6.577

9.3 25.00 2.063 4.459 6.171 9.135

9.6 34.00 2.806 6.065 8.392 12.424

9.9 46.00 3.796 8.205 11.354 16.809

10 53.00 4.374 9.454 13.082 19.367

10.1 66.00 5.446 11.773 16.291 24.117

10.2 96.00 7.922 17.124 23.696 35.079

10.3 157.00 12.956 28.005 38.752 57.369

10.4 255.00 21.043 45.486 62.942 93.180

10.5 312.00 25.747 55.654 77.011 114.008

10.6 300.00 24.756 53.513 74.049 109.623

10.7 251.00 20.713 44.773 61.955 91.718

10.8 199.00 16.422 35.497 49.119 72.717

11 126.00 10.398 22.476 31.101 46.042

11.2 90.00 7.427 16.054 22.215 32.887

11.4 73.00 6.024 13.022 18.019 26.675

11.6 64.00 5.281 11.416 15.797 23.386

Pre-Developed Post-Developed

11.8 59.00 4.869 10.524 14.563 21.559 12 56.00 4.621 9.989 13.823 20.463

12.3 52.00 4.291 9.276 12.835 19.001

12.6 48.00 3.961 8.562 11.848 17.540

13 44.00 3.631 7.849 10.861 16.078

13.5 40.00 3.301 7.135 9.873 14.616

14 36.00 2.971 6.422 8.886 13.155

14.5 32.00 2.641 5.708 7.899 11.693

15 30.00 2.476 5.351 7.405 10.962

15.5 29.00 2.393 5.173 7.158 10.597

16 28.00 2.311 4.995 6.911 10.232 17 26.00 2.146 4.638 6.418 9.501 18 25.00 2.063 4.459 6.171 9.135 20 21.00 1.733 3.746 5.183 7.674 24 14.00 1.155 2.497 3.456 5.116

Note: Curve Number was determined from Natural Resources Conservation Service, U.S. Department of Agriculture, Technical Release, TR-55, Urban Hydrology for Small Watersheds. Second edition 1986.

9 10 11 12 13 14 15

Fl ow

(c fs

Time (hours)

Hydrographs

Post-Dev 2-year

Post-Dev 10-Year

Post-Dev 100-Year

Post-Dev 25 Year

Note: Estimates the time of concentration using equations from HEC-22

Project Sub-Basin: BASIN A

Time of Concentration

Sheet Flow Tc Eq 3.3

For this Basin:

n = 0.15 L = 80 ft I = 4.13 inches/hr s = 0.013 ft/ft

Tt = 8.65 Min

Shallow Concentrated Tc

Eq 3.4

Tc = L/(60V) Eq 3.6

Ku 3.28 k 0.213 s = 0.85 % V = 0.64 ft/s L= 300.00

Tc = 7.76 min

Open Channel (Channel and/or Pipe) Tc

V = (1.486R2/3 s1/2)/n Eq 3.5

Tc = L/(60V) Eq 3.6

V = average velocity, ft/s R = hydraulic radisus = A/WP, ft

A = flow area = [Bd]+[d2/2(Z1+Z2)], ft

WP = wetted perimeter of channel = bd +[d/sin(tan-1(1/Z1))+d/sin(tan-1(1/Z2))], ft B = bottom width of gutter or ditch, ft d = depth of flow in channel, ft - 10-year depth

Z1 = inverse of cross slope one of channel Z2 = inverse of cross slope two of channel s = land slope, ft/ft n = Manning's roughness coefficient

Tc = time of concentration, min L = flow length, ft D= Pipe Diameter, ft

For this Basin: Open Channel L = 2000 ft

Z1 = 35 Z2 = 35 B = 0 ft n = 0.035 s = 0.03 ft/ft d* = 0.6420 ft

A = 14.43 ft2

WP = 23.23 ft R = 0.621 ft Open Channel V = 5.34 ft/s Q (assumed) = 77.01 cfs

Open Channel Tc = 6.24 min Q (actual) = 77.09 cfs

*Iterate this depth until Q(assumed) = Q(actual)

Sheet Flow Tc + Shallow Concentrated Tc + Open Channel Tc = 22.65 min

Return Frequency 24-Hour Precip Depth

(in) 100 4.52 50 4.01 25 3.53 10 2.92 5 2.49 2 1.96

Project Sub-Basin Name B

Grassland or Range 81 353,800 28,657,800

Total 353,800 28,657,800 Total Area (ac) 8.122 Weighted CN 81.00

SR 2.35

Basin Area 0.012690829 mi2

Ia = 0.2SR : 0.469

Ia/P

(Calculated) Ia/P

(Selected)

100 Year 2.57 4.52 0.10 0.1

50 Year 2.13 4.01 0.12 25 Year 1.73 3.53 0.13 0.1 10 Year 1.25 2.92 0.16 0.1 5 Year 0.94 2.49 0.19 2 Year 0.58 1.96 0.24 0.3

Project Sub-Basin Name B

Basin Area: 0.012690829 mi2

ActualTravel Time: 0.25 QD QD QD QD QD QD QD

Selected Travel Time: 0.20 0.00 0.00 0.00 0.58 1.25 1.73 2.57

Time Unit Discharge

(csm/in) 2-Year Flow

(cfs) 10-Year Flow

(cfs) 100-Year Flow

(cfs) 2-Year Flow

(cfs) 10-Year

Flow (cfs) 25-Year

Flow (cfs) 100-Year Flow (cfs)

9 23.00 0.169 0.366 0.506 0.749

9.3 30.00 0.221 0.477 0.660 0.977

9.6 41.00 0.301 0.652 0.902 1.335

9.9 60.00 0.441 0.954 1.320 1.953

10 82.00 0.603 1.303 1.803 2.670

10.1 129.00 0.948 2.050 2.837 4.200

10.2 227.00 1.669 3.608 4.992 7.390

10.3 361.00 2.654 5.737 7.939 11.753

10.4 360.00 2.647 5.721 7.917 11.720

10.5 269.00 1.978 4.275 5.916 8.758

10.6 194.00 1.426 3.083 4.266 6.316

10.7 147.00 1.081 2.336 3.233 4.786

10.8 118.00 0.868 1.875 2.595 3.842

11 85.00 0.625 1.351 1.869 2.767

11.2 71.00 0.522 1.128 1.561 2.312

11.4 63.00 0.463 1.001 1.385 2.051

11.6 58.00 0.426 0.922 1.276 1.888

11.8 55.00 0.404 0.874 1.210 1.791

12 53.00 0.390 0.842 1.166 1.726

12.3 49.00 0.360 0.779 1.078 1.595

12.6 46.00 0.338 0.731 1.012 1.498

13 43.00 0.316 0.683 0.946 1.400

13.5 39.00 0.287 0.620 0.858 1.270

14 35.00 0.257 0.556 0.770 1.139

14.5 31.00 0.228 0.493 0.682 1.009

15 29.00 0.213 0.461 0.638 0.944

15.5 29.00 0.213 0.461 0.638 0.944

16 28.00 0.206 0.445 0.616 0.912 17 26.00 0.191 0.413 0.572 0.846 18 24.00 0.176 0.381 0.528 0.781 20 21.00 0.154 0.334 0.462 0.684 24 14.00 0.103 0.222 0.308 0.456

Note: Curve Number was determined from Natural Resources Conservation Service, U.S. Department of Agriculture, Technical Release, TR-55, Urban Hydrology for Small Watersheds. Second edition 1986.

9 10 11 12 13 14 15

Fl ow

(c fs

Time (hours)

Hydrographs

Post-Dev 2-year

Post-Dev 10-Year

Project Sub-Basin: BASIN B

L = 80 ft I = 4.78 inches/hr s = 0.022 ft/ft

Tt = 6.96 Min

Ku 3.28 k 0.213 s = 2.2 % V = 1.04 ft/s L= 300.00

Tc = 4.83 min

Open Channel (Channel and/or Pipe) Tc

V = (1.486R2/3 s1/2)/n Eq 3.5

Tc = L/(60V) Eq 3.6

V = average velocity, ft/s R = hydraulic radisus = A/WP, ft

A = flow area = [Bd]+[d2/2(Z1+Z2)], ft

WP = wetted perimeter of channel = bd +[d/sin(tan-1(1/Z1))+d/sin(tan-1(1/Z2))], ft B = bottom width of gutter or ditch, ft d = depth of flow in channel, ft - 10-year depth

Z1 = inverse of cross slope one of channel

L = flow length, ft D= Pipe Diameter, ft

For this Basin: Open Channel segment 1 L = 355 ft

Z1 = 10 Z2 = 10 B = 0 ft n = 0.032 s = 0.06 ft/ft d* = 0.1000 ft

A = 0.10 ft2

WP = 1.11 ft R = 0.090 ft V = 2.27 ft/s

Open Channel Tc = 2.60 min

For this Basin: Open Channel segment 2 L = 675 ft

Z1 = 2 Open Chan Z2 = 2 Q (assumed) = 7.94 cfs B = 0 ft Q (actual) = 7.93 cfs n = 0.023 *Iterate this depth until Q(assumed) = Q(actual) s = 0.082 ft/ft d* = 0.5600 ft

A = 0.63 ft2

WP = 1.11 ft R = 0.567 ft V = 12.65 ft/s

Open Channel Tc = 0.89 min

Tc= 3.4931

Sheet Flow Tc + Shallow Concentrated Tc + Open Channel Tc = 15.28 min

24-Hour Precip Depth

(in) 100 4.52 50 4.01 25 3.53 10 2.92 5 2.49 2 1.96

Project Sub-Basin Name C

Range/Grassland 81 155,269 12,576,789 Mountain brush mixture 63 311,657 19,634,391

Total 466,926 32,211,180 Total Area (ac) 10.719 Weighted CN 68.99

SR 4.50

Basin Area 0.016748666 mi2

Ia = 0.2SR : 0.899

Ia/P

(Calculated)

Ia/P (Selected)

100 Year 1.62 4.52 0.20 0.1

50 Year 1.27 4.01 0.22 25 Year 0.97 3.53 0.25 0.3 10 Year 0.63 2.92 0.31 0.1 5 Year 0.42 2.49 0.36 2 Year 0.20 1.96 0.46 0.3

Note: Estimates the peak flow using the NRCS Tabular Hydrograph Method (HEC-22, Manual)

Project Sub-Basin Name C

Basin Area: 0.016748666 mi2

ActualTravel Time: 0.64 QD QD QD QD QD QD QD

Selected Travel Time: 0.50 0.00 0.00 0.00 0.20 0.63 0.97 1.62

Time Unit Discharge

(csm/in) 2-Year Flow (cfs) 10-Year Flow

(cfs) 100-Year Flow

(cfs) 2-Year Flow

(cfs) 10-Year

Flow (cfs) 25-Year

Flow (cfs) 100-Year Flow (cfs)

9 18.00 0.061 0.189 0.293 0.487

9.3 24.00 0.081 0.252 0.390 0.649

9.6 32.00 0.109 0.336 0.521 0.866

9.9 44.00 0.149 0.462 0.716 1.190

10 50.00 0.170 0.525 0.813 1.353

10.1 61.00 0.207 0.640 0.992 1.650

10.2 84.00 0.285 0.882 1.366 2.273

10.3 133.00 0.451 1.396 2.163 3.598

10.4 214.00 0.726 2.246 3.481 5.789

10.5 280.00 0.950 2.939 4.555 7.575

10.6 293.00 0.994 3.075 4.766 7.927

10.7 265.00 0.899 2.781 4.311 7.169

10.8 221.00 0.750 2.320 3.595 5.979

11 144.00 0.488 1.511 2.342 3.896

11.2 99.00 0.336 1.039 1.610 2.678

11.4 77.00 0.261 0.808 1.253 2.083

11.6 66.00 0.224 0.693 1.074 1.786

11.8 60.00 0.204 0.630 0.976 1.623

12 56.00 0.190 0.588 0.911 1.515

12.3 52.00 0.176 0.546 0.846 1.407

12.6 49.00 0.166 0.514 0.797 1.326

13 45.00 0.153 0.472 0.732 1.217

13.5 41.00 0.139 0.430 0.667 1.109

14 37.00 0.126 0.388 0.602 1.001

14.5 32.00 0.109 0.336 0.521 0.866

15 30.00 0.102 0.315 0.488 0.812

15.5 29.00 0.098 0.304 0.472 0.785

16 28.00 0.095 0.294 0.455 0.758 17 27.00 0.092 0.283 0.439 0.730 18 25.00 0.085 0.262 0.407 0.676 20 21.00 0.071 0.220 0.342 0.568 24 14.00 0.047 0.147 0.228 0.379

9 10 11 12 13 14 15

Fl ow

(c fs

Time (hours)

Hydrographs

Post-Dev 2-year

Post-Dev 10-Year

Project Sub-Basin: BASIN C n = 0.4 L = 80 ft I = 2.93 inches/hr s = 0.012 ft/ft

Tt = 18.30 Min

Ku 3.28 k 0.152 s = 1.4 % V = 0.59 ft/s L= 300.00

Tc = 8.48 min

Open Channel (Channel and/or Pipe) Tc

V = (1.486R2/3 s1/2)/n Eq 3.5

Tc = L/(60V) Eq 3.6

V = average velocity, ft/s R = hydraulic radisus = A/WP, ft

A = flow area = [Bd]+[d2/2(Z1+Z2)], ft

WP = wetted perimeter of channel = bd +[d/sin(tan-1(1/Z1))+d/sin(tan-1(1/Z2))], ft B = bottom width of gutter or ditch, ft d = depth of flow in channel, ft - 10-year depth

Z1 = inverse of cross slope one of channel

L = flow length, ft D= Pipe Diameter, ft

For this Basin: Open Channel Segment 1 L = 1220 ft

Z1 = 30 Z2 = 30 B = 0 ft n = 0.035 s = 0.05 ft/ft d* = 0.1000 ft

A = 0.30 ft2

WP = 3.11 ft R = 0.096 ft V = 1.98 ft/s

Open Channel Tc1 = 10.27 min

Open Channel Segment 2

L = 165 Z1 = 10 Z2 = 10 B = 0 n = 0.035 s = 0.18 d* = 0.3500 A = 1.23

WP = 3.11

R = 0.393 V = 9.64

Open Channel Tc2 = 0.29

Open Channel Segment 3 L = 465

Z1 = 2 Z2 = 2 B = 0 n = 0.023 s = 0.12 d* = 0.5590 A = 0.62

WP = 3.11

R = 0.201 V = 7.63

Open Channel Tc3 = 1.02

Open Chan Tc= 11.57 min Q (assumed) = 4.77 cfs

Q (actual) = 4.77 cfs

Sheet Flow Tc + Shallow Concentrated Tc + Open Channel Tc = 38.35 min

24-Hour Precip Depth

(in) 100 4.52 50 4.01 25 3.53 10 2.92 5 2.49 2 1.96

Project Sub-Basin Name D

Range/Grassland 81 283,000 22,923,000 Mountain brush mixture 63 1,109,554 69,901,902

Total 1,392,554 92,824,902 Total Area (ac) 31.969 Weighted CN 66.66

SR 5.00

Basin Area 0.049951001 mi2

Ia = 0.2SR : 1.000

Ia/P

(Calculated) Ia/P

(Selected)

100 Year 1.45 4.52 0.22 0.1

50 Year 1.13 4.01 0.25 25 Year 0.85 3.53 0.28 0.3 10 Year 0.53 2.92 0.34 0.1 5 Year 0.34 2.49 0.40 2 Year 0.15 1.96 0.51 0.3

Note: Estimates the peak flow using the NRCS Tabular Hydrograph Method (HEC-22, Manual)

Project Sub-Basin Name D

Basin Area: 0.049951001 mi2

ActualTravel Time: 0.68 QD QD QD QD QD QD QD

Selected Travel Time: 0.75 0.00 0.00 0.00 0.15 0.53 0.85 1.45

Time Unit Discharge

(csm/in) 2-Year Flow (cfs) 10-Year Flow

(cfs) 100-Year Flow

(cfs) 2-Year Flow

(cfs) 10-Year

Flow (cfs) 25-Year

Flow (cfs) 100-Year Flow (cfs)

9 14.00 0.108 0.372 0.594 1.017

9.3 19.00 0.147 0.505 0.806 1.380

9.6 25.00 0.193 0.665 1.061 1.815

9.9 34.00 0.262 0.904 1.443 2.469

10 38.00 0.293 1.011 1.613 2.759

10.1 43.00 0.332 1.143 1.825 3.122

10.2 49.00 0.378 1.303 2.080 3.558

10.3 62.00 0.478 1.649 2.631 4.502

10.4 88.00 0.679 2.340 3.735 6.390

10.5 134.00 1.034 3.563 5.687 9.730

10.6 190.00 1.466 5.053 8.063 13.796

10.7 234.00 1.805 6.223 9.931 16.991

10.8 252.00 1.944 6.701 10.695 18.298

11 221.00 1.705 5.877 9.379 16.047

11.2 162.00 1.250 4.308 6.875 11.763

11.4 115.00 0.887 3.058 4.881 8.351

11.6 87.00 0.671 2.314 3.692 6.317

11.8 71.00 0.548 1.888 3.013 5.156

12 63.00 0.486 1.675 2.674 4.575

12.3 56.00 0.432 1.489 2.377 4.066

12.6 52.00 0.401 1.383 2.207 3.776

13 47.00 0.363 1.250 1.995 3.413

13.5 43.00 0.332 1.143 1.825 3.122

14 39.00 0.301 1.037 1.655 2.832

14.5 35.00 0.270 0.931 1.485 2.541

15 31.00 0.239 0.824 1.316 2.251

15.5 29.00 0.224 0.771 1.231 2.106

16 29.00 0.224 0.771 1.231 2.106 17 27.00 0.208 0.718 1.146 1.961 18 25.00 0.193 0.665 1.061 1.815 20 22.00 0.170 0.585 0.934 1.597 24 15.00 0.116 0.399 0.637 1.089

Note: Curve Number was determined from Natural Resources Conservation Service, U.S. Department of Agriculture, Technical Release, TR-55, Urban Hydrology for Small Watersheds. Second edition 1986.

9 10 11 12 13 14 15

Fl ow

(c fs

Time (hours)

Hydrographs

Post-Dev 2-year

Post-Dev 10-Year

Project Sub-Basin: BASIN D

Time of Concentration n = 0.4 L = 80 ft I = 2.75 inches/hr s = 0.01 ft/ft

Tt = 19.83 Min

Ku 3.28 k 0.152 s = 1 % V = 0.50 ft/s L= 300.00

Tc = 10.03 min

Open Channel (Channel and/or Pipe) Tc

V = (1.486R2/3 s1/2)/n Eq 3.5

Tc = L/(60V) Eq 3.6

V = average velocity, ft/s R = hydraulic radisus = A/WP, ft

A = flow area = [Bd]+[d2/2(Z1+Z2)], ft

WP = wetted perimeter of channel = bd +[d/sin(tan-1(1/Z1))+d/sin(tan-1(1/Z2))], ft B = bottom width of gutter or ditch, ft d = depth of flow in channel, ft - 10-year depth

Z1 = inverse of cross slope one of channel

L = flow length, ft D= Pipe Diameter, ft

For this Basin: Open Channel L = 927 ft

Z1 = 30 Z2 = 30 B = 0 ft n = 0.023 s = 0.04 ft/ft d* = 0.1500 ft

A = 0.68 ft2

WP = 4.67 ft R = 0.144 ft V = 3.54 ft/s

Open Channel Tc1 = 4.37 min

For this Basin: Open Channel L = 490 ft

Z1 = 10 Z2 = 10 B = 0 ft n = 0.035 s = 0.25 ft/ft d* = 0.1000 ft

A = 0.10 ft2

WP = 4.67 ft R = 0.021 ft V = 1.62 ft/s

Open Channel Tc2 = 5.05 min

For this Basin: Open Channel L = 640 ft

Z1 = 2 Z2 = 2 B = 2 ft n = 0.023 s = 0.07 ft/ft Open Channel d* = 0.5300 ft Q (assumed) = 10.69 cfs

A = 1.62 ft2 Q (actual) = 10.75 cfs WP = 6.67 ft *Iterate this depth until Q(assumed) = Q(actual)

R = 0.243 ft V = 6.63 ft/s

Open Channel Tc3 = 1.61 min

Tc 11.03 min

Sheet Flow Tc + Shallow Concentrated Tc + Open Channel Tc = 40.89 min

24-Hour Precip Depth

(in) 100 4.52 50 4.01 25 3.53 10 2.92 5 2.49 2 1.96

Project Sub-Basin Name E

Grassland or Range (HSG C) 63 227,895 14,357,385

Total 227,895 14,357,385 Total Area (ac) 5.232 Weighted CN 63.00

SR 5.87

Basin Area 0.008174608 mi2

Ia = 0.2SR : 1.175

Ia/P

(Calculated) Ia/P

(Selected)

100 Year 1.21 4.52 0.26 0.1

50 Year 0.92 4.01 0.29 25 Year 0.67 3.53 0.33 0.3 10 Year 0.40 2.92 0.40 0.1 5 Year 0.24 2.49 0.47 2 Year 0.09 1.96 0.60 0.3

Note: Estimates the peak flow using the NRCS Tabular Hydrograph Method (HEC-22, Manual)

Project Sub-Basin Name E

Basin Area: 0.008174608 mi

ActualTravel Time: 0.14 QD QD QD QD QD QD QD

Selected Travel Time: 0.20 0.00 0.00 0.00 0.09 0.40 0.67 1.21

Time

Unit Discharge

(csm/in) 2-Year Flow (cfs)

10-Year Flow

(cfs)

100-Year Flow

(cfs)

2-Year Flow

(cfs)

10-Year

Flow (cfs)

25-Year

Flow (cfs)

100-Year

Flow (cfs)

9 23.00 0.017 0.075 0.127 0.228

9.3 30.00 0.023 0.098 0.165 0.298

9.6 41.00 0.031 0.134 0.226 0.407

9.9 60.00 0.045 0.196 0.331 0.595

10 82.00 0.062 0.268 0.452 0.814

10.1 129.00 0.098 0.422 0.711 1.280

10.2 227.00 0.172 0.742 1.251 2.253

10.3 361.00 0.273 1.180 1.990 3.583

10.4 360.00 0.273 1.177 1.984 3.573

10.5 269.00 0.204 0.879 1.483 2.670

10.6 194.00 0.147 0.634 1.069 1.925

10.7 147.00 0.111 0.481 0.810 1.459

10.8 118.00 0.089 0.386 0.650 1.171

11 85.00 0.064 0.278 0.468 0.844

11.2 71.00 0.054 0.232 0.391 0.705

11.4 63.00 0.048 0.206 0.347 0.625

11.6 58.00 0.044 0.190 0.320 0.576

11.8 55.00 0.042 0.180 0.303 0.546

12 53.00 0.040 0.173 0.292 0.526

12.3 49.00 0.037 0.160 0.270 0.486

12.6 46.00 0.035 0.150 0.254 0.457 13 43.00 0.033 0.141 0.237 0.427

13.5 39.00 0.030 0.127 0.215 0.387 14 35.00 0.027 0.114 0.193 0.347

14.5 31.00 0.023 0.101 0.171 0.308 15 29.00 0.022 0.095 0.160 0.288

15.5 29.00 0.022 0.095 0.160 0.288 16 28.00 0.021 0.092 0.154 0.278 17 26.00 0.020 0.085 0.143 0.258 18 24.00 0.018 0.078 0.132 0.238 20 21.00 0.016 0.069 0.116 0.208 24 14.00 0.011 0.046 0.077 0.139

Note: Curve Number was determined from Natural Resources Conservation Service, U.S. Department of Agriculture, Technical Release, TR-55, Urban Hydrology for Small Watersheds. Second edition 1986.

9 10 11 12 13 14 15

Fl ow

(c fs

Time (hours)

Hydrographs

Post-Dev 2-year

Post-Dev 10-Year

Project Sub-Basin: BASIN E

L = 80 ft I = 6.1 inches/hr s = 0.3 ft/ft

Tt = 2.88 Min

Ku 3.28 k 0.213 s = 35 % V = 4.13 ft/s L= 300.00

Tc = 1.21 min

Open Channel (Channel and/or Pipe) Tc

V = (1.486R2/3 s1/2)/n Eq 3.5

Tc = L/(60V) Eq 3.6

V = average velocity, ft/s R = hydraulic radisus = A/WP, ft

A = flow area = [Bd]+[d2/2(Z1+Z2)], ft

WP = wetted perimeter of channel = bd +[d/sin(tan-1(1/Z1))+d/sin(tan-1(1/Z2))], ft B = bottom width of gutter or ditch, ft d = depth of flow in channel, ft - 10-year depth

Z1 = inverse of cross slope one of channel

L = flow length, ft D= Pipe Diameter, ft

For this Basin: Open Channel L = 960 ft

Z1 = 10 Z2 = 10 B = 0 ft n = 0.023 s = 0.025 ft/ft d* = 0.2350 ft

A = 0.55 ft2

WP = 2.60 ft R = 0.212 ft Open Channel V = 3.62 ft/s Q (assumed) = 1.99 cfs

Open Channel Tc = 4.42 min Q (actual) = 2.00 cfs

Sheet Flow Tc + Shallow Concentrated Tc + Open Channel Tc = 8.52 min

14 | August 7, 2020

Appendix C.

Culvert Analyses

Outlet Protection Calculations

HY-8 Culvert Analysis Report

Crossing Discharge Data

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

Minimum Flow: 1 cfs

Design Flow: 77.01 cfs

Maximum Flow: 80 cfs

Table 1 - Summary of Culvert Flows at Crossing: STA 136+77_Ex_Culvert

Headwater Elevation

(ft) Total Discharge (cfs) Culvert 1 Discharge

(cfs) Roadway Discharge

(cfs) Iterations

6788.09 1.00 1.00 0.00 1

6789.53 8.90 7.50 1.32 34

6789.61 16.80 7.70 8.97 6

6789.66 24.70 7.91 16.57 4

6789.71 32.60 8.09 24.41 4

6789.75 40.50 8.23 32.23 4

6789.78 48.40 8.35 39.91 3

6789.82 56.30 8.46 47.75 3

6789.85 64.20 8.54 55.61 3

6789.90 77.01 8.73 68.32 3

6789.91 80.00 8.73 71.21 2

6789.50 7.40 7.40 0.00 Overtopping

Table 2 - Culvert Summary Table: Culvert 1

Straight Culvert

Inlet Elevation (invert): 6787.48 ft, Outlet Elevation (invert): 6787.39 ft

Culvert Length: 20.68 ft, Culvert Slope: 0.0044

Total Discharge

(cfs)

Culvert Discharge

(cfs)

Headwater Elevation

(ft)

Inlet Control

Depth (ft)

Outlet Control

Depth (ft) Flow Type

Normal Depth (ft)

Critical Depth (ft)

Outlet Depth (ft)

Tailwater Depth (ft)

Outlet Velocity

(ft/s)

Tailwater Velocity

(ft/s)

1.00 1.00 6788.09 0.550 0.612 2-M2c 0.528 0.373 0.373 0.027 2.918 1.462

8.90 7.50 6789.53 1.946 2.050 7-M2c 1.500 1.061 1.061 0.097 5.615 3.296

16.80 7.70 6789.61 1.996 2.132 7-M2c 1.500 1.075 1.075 0.140 5.682 4.116

24.70 7.91 6789.66 2.050 2.181 7-M2c 1.500 1.090 1.090 0.174 5.755 4.688

32.60 8.09 6789.71 2.097 2.226 7-M2c 1.500 1.102 1.102 0.204 5.816 5.138

40.50 8.23 6789.75 2.134 2.267 7-M2c 1.500 1.111 1.111 0.230 5.862 5.512

48.40 8.35 6789.78 2.167 2.305 7-M2c 1.500 1.119 1.119 0.254 5.904 5.836

56.30 8.46 6789.82 2.199 2.340 7-M2c 1.500 1.127 1.127 0.276 5.945 6.119

64.20 8.54 6789.85 2.222 2.374 7-M2c 1.500 1.132 1.132 0.297 5.973 6.373

77.01 8.73 6789.90 2.274 2.423 7-M2c 1.500 1.143 1.143 0.328 6.037 6.739

80.00 8.73 6789.91 2.276 2.435 7-M2c 1.500 1.144 1.144 0.335 6.040 6.816

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: 6787.48 ft

Outlet Station: 20.68 ft

Outlet Elevation: 6787.39 ft

Number of Barrels: 1

Culvert Data Summary - Culvert 1

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

Minimum Flow: 1 cfs

Design Flow: 7.94 cfs

Maximum Flow: 25 cfs

Table 4 - Summary of Culvert Flows at Crossing: STA 159+25_Ex_Culvert

(cfs) Roadway Discharge

(cfs) Iterations

6785.99 1.00 1.00 0.00 1

6786.43 3.40 3.40 0.00 1

6786.77 5.80 5.80 0.00 1

6787.04 7.94 7.94 0.00 1

6787.38 10.60 10.60 0.00 1

6787.70 13.00 13.00 0.00 1

6788.07 15.40 15.40 0.00 1

6788.25 17.80 16.48 1.27 11

6788.29 20.20 16.73 3.43 5

6788.32 22.60 16.93 5.62 4

6788.36 25.00 17.10 7.88 4

6788.20 16.21 16.21 0.00 Overtopping

Table 5 - Culvert Summary Table: Culvert 1

Total Discharge

(cfs)

Culvert Discharge

(cfs)

Headwater Elevation

(ft)

Inlet Control

Depth (ft)

Outlet Control

Depth (ft) Flow Type

Normal Depth (ft)

Critical Depth (ft)

Outlet Depth (ft)

Tailwater Depth (ft)

Outlet Velocity

(ft/s)

Tailwater Velocity

(ft/s)

1.00 1.00 6785.99 0.491 0.0* 1-S2n 0.289 0.344 0.289 0.139 3.556 3.157

3.40 3.40 6786.43 0.933 0.045 1-S2n 0.531 0.645 0.531 0.281 5.081 4.723

5.80 5.80 6786.77 1.267 0.347 1-S2n 0.701 0.851 0.701 0.378 5.906 5.562

7.94 7.94 6787.04 1.541 0.626 1-S2n 0.831 1.003 0.836 0.449 6.380 6.104

10.60 10.60 6787.38 1.879 1.003 1-S2n 0.979 1.166 0.987 0.524 6.863 6.633

13.00 13.00 6787.70 2.203 1.379 5-S2n 1.107 1.297 1.116 0.584 7.216 7.027

15.40 15.40 6788.07 2.567 1.792 5-S2n 1.234 1.415 1.242 0.638 7.510 7.368

17.80 16.48 6788.25 2.746 1.990 5-S2n 1.292 1.463 1.301 0.688 7.617 7.669

20.20 16.73 6788.29 2.790 2.037 5-S2n 1.306 1.474 1.315 0.734 7.642 7.941

22.60 16.93 6788.32 2.824 2.074 5-S2n 1.317 1.483 1.325 0.777 7.661 8.186

25.00 17.10 6788.36 2.855 2.107 5-S2n 1.326 1.490 1.335 0.817 7.677 8.413

* Full Flow Headwater elevation is below inlet invert.

Straight Culvert

Inlet Elevation (invert): 6785.50 ft, Outlet Elevation (invert): 6784.85 ft

Culvert Length: 20.29 ft, Culvert Slope: 0.0321

Inlet Station: 0.00 ft

Inlet Elevation: 6785.50 ft

Outlet Station: 20.28 ft

Outlet Elevation: 6784.85 ft

Number of Barrels: 1

Culvert Data Summary - Culvert 1

Barrel Shape: Circular

Barrel Diameter: 2.00 ft

Barrel Material: Corrugated Steel

Embedment: 0.00 in

Barrel Manning's n: 0.0240

Culvert Type: Straight

Minimum Flow: 1 cfs

Design Flow: 4.77 cfs

Maximum Flow: 10 cfs

Table 7 - Summary of Culvert Flows at Crossing: STA 166+50_Ex_Culvert

(cfs) Roadway Discharge

(cfs) Iterations

6726.98 1.00 1.00 0.00 1

6727.17 1.90 1.90 0.00 1

6727.32 2.80 2.80 0.00 1

6727.46 3.70 3.70 0.00 1

6727.61 4.77 4.77 0.00 1

6727.70 5.50 5.50 0.00 1

6727.82 6.40 6.40 0.00 1

6727.94 7.30 7.30 0.00 1

6728.05 8.20 8.20 0.00 1

6728.16 9.10 9.10 0.00 1

6728.28 10.00 10.00 0.00 1

6728.50 11.69 11.69 0.00 Overtopping

Table 8 - Culvert Summary Table: Culvert 1

(cfs)

Culvert Discharge

(cfs)

Headwater Elevation

(ft)

Inlet Control

Depth (ft)

Outlet Control

Depth (ft) Flow Type

Normal Depth (ft)

Critical Depth (ft)

Outlet Depth (ft)

Tailwater Depth (ft)

Outlet Velocity

(ft/s)

Tailwater Velocity

(ft/s)

1.00 1.00 6726.98 0.481 0.0* 1-S2n 0.256 0.344 0.256 0.043 4.261 3.279

1.90 1.90 6727.17 0.672 0.0* 1-S2n 0.349 0.478 0.349 0.062 5.165 4.208

2.80 2.80 6727.32 0.824 0.0* 1-S2n 0.422 0.583 0.422 0.079 5.787 4.874

3.70 3.70 6727.46 0.956 0.0* 1-S2n 0.485 0.674 0.485 0.093 6.276 5.422

4.77 4.77 6727.61 1.106 0.0* 1-S2n 0.552 0.768 0.552 0.108 6.749 5.958

5.50 5.50 6727.70 1.205 0.0* 1-S2n 0.594 0.828 0.594 0.117 7.029 6.289

6.40 6.40 6727.82 1.323 0.0* 1-S2n 0.643 0.896 0.643 0.128 7.335 6.652

7.30 7.30 6727.94 1.438 0.0* 1-S2n 0.689 0.960 0.689 0.138 7.609 6.982

8.20 8.20 6728.05 1.552 0.0* 1-S2n 0.733 1.020 0.741 0.148 7.742 7.283

9.10 9.10 6728.16 1.665 0.0* 1-S2n 0.776 1.077 0.776 0.158 8.081 7.564

10.00 10.00 6728.28 1.779 0.105 1-S2n 0.817 1.131 0.817 0.167 8.289 7.830

Straight Culvert

Inlet Elevation (invert): 6726.50 ft, Outlet Elevation (invert): 6724.99 ft

Culvert Length: 27.93 ft, Culvert Slope: 0.0541

Inlet Station: 0.00 ft

Inlet Elevation: 6726.50 ft

Outlet Station: 27.89 ft

Outlet Elevation: 6724.99 ft

Number of Barrels: 1

Culvert Data Summary - Culvert 1

Barrel Shape: Circular

Barrel Diameter: 2.00 ft

Barrel Material: Corrugated Steel

Embedment: 0.00 in

Barrel Manning's n: 0.0240

Culvert Type: Straight

Minimum Flow: 5 cfs

Design Flow: 10.69 cfs

Maximum Flow: 30 cfs

Table 10 - Summary of Culvert Flows at Crossing: STA 173+72_Ex_Culvert

(cfs) Roadway Discharge

(cfs) Iterations

6656.00 5.00 5.00 0.00 1

6656.33 7.50 7.50 0.00 1

6656.73 10.69 10.69 0.00 1

6656.97 12.50 12.50 0.00 1

6657.34 15.00 15.00 0.00 1

6657.54 17.50 16.23 1.19 12

6657.59 20.00 16.50 3.44 5

6657.63 22.50 16.71 5.72 4

6657.66 25.00 16.89 8.08 4

6657.69 27.50 17.05 10.36 3

6657.71 30.00 17.20 12.73 3

6657.50 15.97 15.97 0.00 Overtopping

Table 11 - Culvert Summary Table: Culvert 1

(cfs)

Culvert Discharge

(cfs)

Headwater Elevation

(ft)

Inlet Control

Depth (ft)

Outlet Control

Depth (ft) Flow Type

Normal Depth (ft)

Critical Depth (ft)

Outlet Depth (ft)

Tailwater Depth (ft)

Outlet Velocity

(ft/s)

Tailwater Velocity

(ft/s)

5.00 5.00 6656.00 1.129 0.0* 1-S2n 0.546 0.788 0.552 0.096 7.078 6.061

7.50 7.50 6656.33 1.455 0.0* 1-S2n 0.674 0.973 0.684 0.118 7.904 6.791

10.69 10.69 6656.73 1.860 0.117 1-S2n 0.816 1.172 0.831 0.141 8.664 7.480

12.50 12.50 6656.97 2.103 0.414 5-S2n 0.890 1.271 0.908 0.152 9.014 7.804

15.00 15.00 6657.34 2.473 0.861 5-S2n 0.988 1.396 1.011 0.166 9.422 8.194

17.50 16.23 6657.54 2.674 1.098 5-S2n 1.036 1.452 1.061 0.179 9.588 8.540

20.00 16.50 6657.59 2.720 1.151 5-S2n 1.046 1.464 1.072 0.191 9.624 8.845

22.50 16.71 6657.63 2.756 1.192 5-S2n 1.054 1.473 1.080 0.201 9.651 9.123

25.00 16.89 6657.66 2.788 1.229 5-S2n 1.061 1.481 1.087 0.211 9.676 9.381

27.50 17.05 6657.69 2.815 1.260 5-S2n 1.067 1.488 1.094 0.221 9.697 9.615

30.00 17.20 6657.71 2.842 1.291 5-S2n 1.073 1.495 1.100 0.230 9.717 9.843

Straight Culvert

Inlet Elevation (invert): 6654.87 ft, Outlet Elevation (invert): 6653.28 ft

Culvert Length: 25.66 ft, Culvert Slope: 0.0621

Inlet Station: 0.00 ft

Inlet Elevation: 6654.87 ft

Outlet Station: 25.61 ft

Outlet Elevation: 6653.28 ft

Number of Barrels: 1

Culvert Data Summary - Culvert 1

Barrel Shape: Circular

Barrel Diameter: 2.00 ft

Barrel Material: Corrugated Steel

Embedment: 0.00 in

Barrel Manning's n: 0.0240

Culvert Type: Straight

Minimum Flow: 1 cfs

Design Flow: 1.99 cfs

Table 13 - Summary of Culvert Flows at Crossing: STA 182+56_Ex_Culvert

(cfs) Roadway Discharge

(cfs) Iterations

6549.19 1.00 1.00 0.00 1

6549.43 1.99 1.99 0.00 1

6549.59 2.80 2.80 0.00 1

6549.74 3.70 3.70 0.00 1

6549.88 4.60 4.60 0.00 1

6550.01 5.50 5.50 0.00 1

6550.13 6.40 6.40 0.00 1

6550.24 7.30 7.30 0.00 1

6550.35 8.20 8.20 0.00 1

6550.46 9.10 9.10 0.00 1

6550.57 10.00 10.00 0.00 1

6552.00 19.15 19.15 0.00 Overtopping

Table 14 - Culvert Summary Table: Culvert 1

Straight Culvert

Inlet Elevation (invert): 6548.64 ft, Outlet Elevation (invert): 6548.28 ft

Culvert Length: 35.27 ft, Culvert Slope: 0.0102

Total Discharge

(cfs)

Culvert Discharge

(cfs)

Headwater Elevation

(ft)

Inlet Control

Depth (ft)

Outlet Control

Depth (ft) Flow Type

Normal Depth (ft)

Critical Depth (ft)

Outlet Depth (ft)

Tailwater Depth (ft)

Outlet Velocity

(ft/s)

Tailwater Velocity

(ft/s)

1.00 1.00 6549.19 0.501 0.550 2-M2c 0.383 0.344 0.344 0.039 2.773 5.572

1.99 1.99 6549.43 0.717 0.789 2-M2c 0.541 0.489 0.489 0.059 3.340 7.303

2.80 2.80 6549.59 0.859 0.946 2-M2c 0.646 0.583 0.583 0.073 3.674 8.334

3.70 3.70 6549.74 0.997 1.099 2-M2c 0.748 0.674 0.674 0.086 3.980 9.271

4.60 4.60 6549.88 1.126 1.238 2-M2c 0.843 0.754 0.754 0.098 4.244 10.082

5.50 5.50 6550.01 1.249 1.366 2-M2c 0.933 0.828 0.828 0.109 4.480 10.801

6.40 6.40 6550.13 1.367 1.487 2-M2c 1.019 0.896 0.896 0.120 4.697 11.434

7.30 7.30 6550.24 1.482 1.602 2-M2c 1.103 0.960 0.960 0.129 4.899 12.012

8.20 8.20 6550.35 1.596 1.714 2-M2c 1.187 1.020 1.020 0.139 5.093 12.555

9.10 9.10 6550.46 1.709 1.822 2-M2c 1.273 1.077 1.077 0.148 5.277 13.058

10.00 10.00 6550.57 1.823 1.930 2-M2c 1.361 1.131 1.131 0.156 5.456 13.531

Inlet Station: 0.00 ft

Inlet Elevation: 6548.64 ft

Outlet Station: 35.27 ft

Outlet Elevation: 6548.28 ft

Number of Barrels: 1

Culvert Data Summary - Culvert 1

Barrel Shape: Circular

Barrel Diameter: 2.00 ft

Barrel Material: Corrugated Steel

Embedment: 0.00 in

Barrel Manning's n: 0.0240

Culvert Type: Straight

Minimum Flow: 1 cfs

Design Flow: 77.01 cfs

Maximum Flow: 80 cfs

Table 16 - Summary of Culvert Flows at Crossing: STA 136+50_Proposed

(cfs) Roadway Discharge

(cfs) Iterations

6787.74 1.00 1.00 0.00 1

6788.25 8.90 8.90 0.00 1

6788.56 16.80 16.80 0.00 1

6788.83 24.70 24.70 0.00 1

6789.08 32.60 32.60 0.00 1

6789.33 40.50 40.50 0.00 1

6789.59 48.40 48.40 0.00 1

6789.87 56.30 56.30 0.00 1

6790.20 64.20 64.20 0.00 1

6790.78 77.01 77.01 0.00 1

6790.93 80.00 80.00 0.00 1

6791.20 84.88 84.88 0.00 Overtopping

Table 17 - Culvert Summary Table: Culvert 1

(cfs)

Culvert Discharge

(cfs)

Headwater Elevation

(ft)

Inlet Control

Depth (ft)

Outlet Control

Depth (ft) Flow Type

Normal Depth (ft)

Critical Depth (ft)

Outlet Depth (ft)

Tailwater Depth (ft)

Outlet Velocity

(ft/s)

Tailwater Velocity

(ft/s)

1.00 1.00 6787.74 0.243 0.0* 1-S2n 0.164 0.171 0.164 0.029 2.033 1.355

8.90 8.90 6788.25 0.752 0.0* 1-S2n 0.477 0.518 0.477 0.106 3.872 3.102

16.80 16.80 6788.56 1.059 0.0* 1-S2n 0.661 0.719 0.661 0.154 4.638 3.897

24.70 24.70 6788.83 1.327 0.0* 1-S2n 0.812 0.879 0.812 0.192 5.156 4.460

32.60 32.60 6789.08 1.578 0.266 1-S2n 0.949 1.016 0.949 0.225 5.546 4.904

40.50 40.50 6789.33 1.828 0.632 1-S2n 1.080 1.139 1.080 0.255 5.852 5.276

48.40 48.40 6789.59 2.089 1.040 5-S2n 1.209 1.250 1.209 0.282 6.096 5.596

56.30 56.30 6789.87 2.371 1.491 5-S2n 1.341 1.351 1.341 0.307 6.286 5.879

64.20 64.20 6790.20 2.684 2.701 7-M2c 1.485 1.444 1.444 0.331 6.607 6.137

77.01 77.01 6790.78 3.276 3.035 7-M2c 2.000 1.578 1.578 0.366 7.242 6.502

80.00 80.00 6790.93 3.431 3.168 7-M2c 2.000 1.606 1.606 0.374 7.397 6.582

Straight Culvert

Inlet Elevation (invert): 6787.50 ft, Outlet Elevation (invert): 6786.30 ft

Culvert Length: 57.01 ft, Culvert Slope: 0.0211

Inlet Station: 0.00 ft

Inlet Elevation: 6787.50 ft

Outlet Station: 57.00 ft

Outlet Elevation: 6786.30 ft

Number of Barrels: 4

Culvert Data Summary - Culvert 1

Barrel Shape: Circular

Barrel Diameter: 2.00 ft

Barrel Material: Corrugated Steel

Embedment: 0.00 in

Barrel Manning's n: 0.0240

Culvert Type: Straight

Minimum Flow: 1 cfs

Design Flow: 7.94 cfs

Maximum Flow: 15 cfs

Table 19 - Summary of Culvert Flows at Crossing: STA 159+25_Pro_Culvert

(cfs) Roadway Discharge

(cfs) Iterations

6785.99 1.00 1.00 0.00 1

6786.27 2.40 2.40 0.00 1

6786.49 3.80 3.80 0.00 1

6786.68 5.20 5.20 0.00 1

6786.87 6.60 6.60 0.00 1

6787.04 7.94 7.94 0.00 1

6787.22 9.40 9.40 0.00 1

6787.40 10.80 10.80 0.00 1

6787.59 12.20 12.20 0.00 1

6787.79 13.60 13.60 0.00 1

6788.00 15.00 15.00 0.00 1

6788.20 16.23 16.23 0.00 Overtopping

Table 20 - Culvert Summary Table: Culvert 1

(cfs)

Culvert Discharge

(cfs)

Headwater Elevation

(ft)

Inlet Control

Depth (ft)

Outlet Control

Depth (ft) Flow Type

Normal Depth (ft)

Critical Depth (ft)

Outlet Depth (ft)

Tailwater Depth (ft)

Outlet Velocity

(ft/s)

Tailwater Velocity

(ft/s)

1.00 1.00 6785.99 0.489 0.0* 1-S2n 0.280 0.344 0.280 0.139 3.741 3.157

2.40 2.40 6786.27 0.771 0.0* 1-S2n 0.430 0.539 0.430 0.231 4.834 4.229

3.80 3.80 6786.49 0.985 0.0* 1-S2n 0.542 0.683 0.542 0.299 5.519 4.890

5.20 5.20 6786.68 1.182 0.076 1-S2n 0.637 0.804 0.637 0.356 6.032 5.383

6.60 6.60 6786.87 1.366 0.257 1-S2n 0.723 0.910 0.728 0.406 6.389 5.781

7.94 7.94 6787.04 1.536 0.437 1-S2n 0.799 1.003 0.799 0.449 6.777 6.104

9.40 9.40 6787.22 1.720 0.644 1-S2n 0.877 1.095 0.885 0.492 7.013 6.409

10.80 10.80 6787.40 1.900 0.854 1-S2n 0.949 1.178 0.959 0.529 7.253 6.669

12.20 12.20 6787.59 2.087 1.077 5-S2n 1.020 1.255 1.029 0.565 7.488 6.904

13.60 13.60 6787.79 2.285 1.312 5-S2n 1.089 1.328 1.100 0.598 7.679 7.118

15.00 15.00 6788.00 2.498 1.561 5-S2n 1.158 1.396 1.170 0.629 7.860 7.315

Straight Culvert

Inlet Elevation (invert): 6785.50 ft, Outlet Elevation (invert): 6784.65 ft

Culvert Length: 23.02 ft, Culvert Slope: 0.0370

Inlet Station: 0.00 ft

Inlet Elevation: 6785.50 ft

Outlet Station: 23.00 ft

Outlet Elevation: 6784.65 ft

Number of Barrels: 1

Culvert Data Summary - Culvert 1

Barrel Shape: Circular

Barrel Diameter: 2.00 ft

Barrel Material: Corrugated Steel

Embedment: 0.00 in

Barrel Manning's n: 0.0240

Culvert Type: Straight

Minimum Flow: 1 cfs

Design Flow: 4.77 cfs

Maximum Flow: 20 cfs

Table 22 - Summary of Culvert Flows at Crossing: STA 166+50_Pro_Culvert

(cfs) Roadway Discharge

(cfs) Iterations

6726.98 1.00 1.00 0.00 1

6727.33 2.90 2.90 0.00 1

6727.60 4.77 4.77 0.00 1

6727.85 6.70 6.70 0.00 1

6728.10 8.60 8.60 0.00 1

6728.34 10.50 10.50 0.00 1

6728.52 12.40 11.90 0.42 14

6728.56 14.30 12.20 2.04 5

6728.59 16.20 12.43 3.72 4

6728.62 18.10 12.63 5.45 4

6728.65 20.00 12.79 7.14 3

6728.50 11.73 11.73 0.00 Overtopping

Table 23 - Culvert Summary Table: Culvert 1

(cfs)

Culvert Discharge

(cfs)

Headwater Elevation

(ft)

Inlet Control

Depth (ft)

Outlet Control

Depth (ft) Flow Type

Normal Depth (ft)

Critical Depth (ft)

Outlet Depth (ft)

Tailwater Depth (ft)

Outlet Velocity

(ft/s)

Tailwater Velocity

(ft/s)

1.00 1.00 6726.98 0.478 0.0* 1-S2n 0.248 0.344 0.248 0.043 4.446 3.279

2.90 2.90 6727.33 0.834 0.0* 1-S2n 0.418 0.594 0.418 0.080 6.087 4.940

4.77 4.77 6727.60 1.099 0.0* 1-S2n 0.536 0.768 0.542 0.108 6.922 5.958

6.70 6.70 6727.85 1.355 0.0* 1-S2n 0.639 0.917 0.639 0.132 7.742 6.766

8.60 8.60 6728.10 1.595 0.0* 1-S2n 0.729 1.045 0.729 0.153 8.297 7.406

10.50 10.50 6728.34 1.837 0.0* 1-S2n 0.813 1.161 0.824 0.172 8.608 7.965

12.40 11.90 6728.52 2.022 0.226 5-S2n 0.872 1.239 0.884 0.189 8.886 8.458

14.30 12.20 6728.56 2.063 0.276 5-S2n 0.884 1.255 0.897 0.206 8.936 8.893

16.20 12.43 6728.59 2.095 0.316 5-S2n 0.893 1.267 0.907 0.221 8.975 9.297

18.10 12.63 6728.62 2.122 0.350 5-S2n 0.901 1.278 0.915 0.236 9.008 9.663

20.00 12.79 6728.65 2.145 0.380 5-S2n 0.908 1.286 0.923 0.250 9.025 10.009

Straight Culvert

Inlet Elevation (invert): 6726.50 ft, Outlet Elevation (invert): 6724.80 ft

Culvert Length: 28.05 ft, Culvert Slope: 0.0607

Inlet Station: 0.00 ft

Inlet Elevation:…