Final Hydraulic Report_Stamped.pdf

Final Hydraulics Report

NM FTBL 2004(1)

Wild Rivers Back Country Byway

Prepared for:

Federal Highway Administration Central Federal Lands Highway Division 12300 West Dakota Avenue Lakewood, CO 80228

July 2020

Prepared By:

Jacobs Engineering Group 9191 South Jamaica Street Englewood, CO 80112

07/27/2020

Wild Rivers Back Country Byway i

Contents

1. Introduction and Purpose

1.1 Project Location

1.2 Project Description

1.3 Previous Studies

1.4 Field Survey

1.5 Floodplain Investigation

1.6 Wetlands Investigation

2. Drainage Design Criteria and Methodology

2.1 General

2.2 Hydrologic Analysis

2.3 Hydraulic Analysis

2.4 Roadside Ditches

2.5 Pavement Drainage

2.6 Erosion Control

2.7 Miscellaneous

3. Hydrologic Analysis

3.1 Major Basin Analysis

3.2 Minor Basin Analysis

4. Hydraulic Analysis

4.1 Major Culverts

4.2 Minor Culverts

4.3 Culvert Material Selection

4.4 Curb Sections and Inlets

4.5 Ditches

5. Recommended Improvements

5.1 Existing Culverts

5.2 Proposed Culvert Improvements

5.3 Montoso Campground Improvements

6. Erosion and Sediment Control

6.1 Construction BMP’s

6.2 Permanent BMP’s

7. References

Wild Rivers Back Country Byway ii

List of Figures

Figure 1.1: Vicinity Map

List of Tables

Table 3.1: Hydrologic Summary - Montoso Campground Table 4.1: Montoso Campground Proposed Culvert Summary

List of Appendices

Appendix A. FEMA FIRM Maps

Appendix B. Culvert Inventory

Appendix C. Hydrologic Analysis

Appendix D. Hydraulic Analysis

Acronyms and Abreviations

ADT Average Daily Traffic BMP Best Management Practices CMP Corrugated Metal Pipe CFLHD Central Federal Lands Highway Division FEMA Federal Emergency Management Agency FES Flared End Section FIRM Flood Insurance Rate Map HDS Hydraulic Design Series HEC Hydraulic Engineering Circular HW/D Headwater Depth per Diameter MP Milepost PPDM Project Development and Design Manual State Route WSE Water Surface Elevation

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1. Introduction and Purpose

This Final Hydraulic Report describes the hydrologic and hydraulic design and drainage improvement recommendations for the Wild Rivers Back Country Byway (BCB). The Wild Rivers BCB is a 12.5-mile two-lane road that offers access points for recreational biking and mountain biking on 3 designated trails, swimming, camping, fishing and hiking on 10 designated trails. The access road is used for school visitations, architectural survey, geology education services, horseback riding, and fishing tour trips.

The purpose of this project is to enhance overall public access to the Wild Rivers area with surfacing improvements to rehabilitate, restore, and resurface the roads and parking areas while encouraging non-vehicular traffic and enhanced livability by improving facilities for bicycle traffic. The project is funded through the Federal Lands Transportation Program (FLTP).

The initial project was subsequently separated into two separate projects: The Entrance Road and the Loop Road, both along the Back-Country Byway. This Final Hydraulics Report describes the project as a whole but focuses on the Loop Road improvements. A separate hydraulics report will be prepared to describe drainage work on the Entrance Road.

1.1 Project Location

The Wild Rivers BCB is located within the Wild Rivers Recreation Area, a portion of the Rio Grande del Norte National Monument in Taos County, New Mexico. It begins 28 miles north of Taos, NM near the town of Cerro, NM, where NM State Highway 378 dead-ends into the Byway. Refer to Figure 1 – Vicinity Map on the next page for a general location of the project.

1.2 Project Description

The initial project was divided into three segments. The first segment includes the 7.75-mile Entrance Road, with the second segment including the 4.75-mile southern loop and the third segment including facilities located throughout the site. Segments 2 and 3 are being proposed to be constructed first with this project and Segment 1 to be constructed as subsequent project due to funding constraints.

1.2.1 Segment 1

The following improvements are being proposed for the entrance road.

Widen paved surface to 30 feet to provide wider shoulders for bicycles. Proposed pavement typical section is two 11-foot lanes and two 6-foot shoulders with safety edge and proper shouldering material to the top of pavement.

Flatten 2 curves near Guadalupe Trail access.

Rebuild (or add) asphalt aprons at approach roads to formal overlooks.

Embankment grading for slope flattening and culvert extensions in several areas.

Culvert cleaning.

Replace signing and pavement markings.

Replace / install delineators as necessary for corridor consistency.

Replace existing cattle guards to match the widened roadway.

Include gate at Chiflo Recreation Access.

Reset guardrail to meet safety standards.

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Figure 1.1: Vicinity Map

1.2.2 Segment 2

The following improvements are being proposed for the loop road.

Change Loop Road traffic pattern. Two‐way traffic will remain from the top of the loop to the Visitor Center.

The rest of the Loop Road will be changed to one‐way traffic (clockwise).

Widen paved surface on two‐way portion matching the Entrance Road.

Utilize existing width of paved surface on one‐way portion of 22 feet (2‐foot left shoulder, 14‐foot lane, and 6‐foot right bike lane).

Install shouldering material to top of pavement.

Embankment grading for slope flattening and culvert extensions in several areas.

Regrade trail crossings to eliminate drop‐offs at edges of roadway.

Loop Road

Entrance Road

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Install sleeves for future waterline repairs.

Culvert cleaning.

Reset guardrail to proper elevations (if it is not removed).

Replace signing, pavement markings, and delineators per new traffic pattern.

1.2.3 Segment 3

The following improvements are being proposed for other areas.

Pave roadway to La Junta Overlook.

Rehabilitate pavement at the Visitor Center parking lot. Minor modification of grades at ADA parking space and ramp to meet criteria.

Recondition aggregate roads servicing:

- Chawalauna Overlook,

- Big Arsenic Campground,

- Little Arsenic Campground,

- Montoso Campground, and

- El Aguaje Campground.

1.3 Previous Studies

No known previous studies have been identified for this area.

1.4 Field Survey

Field survey was completed by Jacobs staff in December 2019 that includes culvert invert, size, type, condition, and evident erosion that will be used for the proposed improvements of the project. Site investigations were also completed to confirm culvert condition. A culvert inventory has been included in Appendix B that includes each culverts assessment for documentation.

1.5 Floodplain Investigation

There are no FEMA regulated floodplain crossings within the project limits as shown in Effective FEMA FIRM Panels 35055C0275E and 35055C0450E dated October 6, 2010. These FIRM maps can be found in Appendix A

1.6 Wetlands Investigation

An initial site investigation conducted on August 1, 2019 with Jacobs and CFLHD staff did not indicate any wetlands that will require mitigation for the proposed improvements as the site is mostly comprised of dry and arid rangeland. Confirmation and delineation of any potential wetlands along with any necessary mitigation will occur in the future with the environmental permitting documents. Fish passage and stream restoration is not required since all culverts convey ephemeral flows. Water Quality will be mitigated during and after construction using temporary and permanent best management practices (BMP’s). Further discussion on erosion control can be found in Section 6 of this report.

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2. Drainage Design Criteria and Methodology

2.1 General

The drainage design for the project will be in accordance with the Federal Lands’ Project Development and Design Manual (PDDM) Chapter 7. The scope of this project includes extending existing culverts that are in fair to good condition and replacing in kind existing culverts in poor condition. Most culverts in the project limits will require no hydrologic or hydraulic analysis since there are not any known overtopping or safety concerns with the existing culverts with the exception of the culvert to be replaced near Montoso Campground. This was confirmed through the initial walkthrough of the project with CFLHD and Jacobs staff. The following sections describe the criteria that will be used for the Montoso Campground culvert analysis.

2.2 Hydrologic Analysis

The Rational Method, using the procedures described in HDS-2, will be used to calculate the flow for the culvert at Montoso Campground since the tributary area is less than 200 acres. All other culverts will remain and will be extended as needed or replaced in kind dependent upon pipe condition, or the need to replace due to future outfall conditions; therefore, no further hydrologic analysis is needed as the existing conditions do not indicate capacity issues. Flowrates will be calculated for the 2, 5, 10, 25 (design), and 50-year (check) storm events per definition of a Low-Standard Road.

2.3 Hydraulic Analysis

The culvert at Montoso Campground has been designed using the FHWA HY-8 computer software utilizing HDS-5 procedures. The crossing is classified as a Low-Standard Road which requires accommodation of the 25-year flood.

The minimum pipe size for new crossing culverts is 24-inches and 18-inches for access road culverts. New culverts will be replaced with the minimum size as cover allows. Equivalent diameter arch pipes will be utilized where low cover exists. Recommended hydraulic design standards and criteria can be found in Exhibit 7.1-A of the PDDM. A maximum headwater to depth ratio of 1.5 will be used for minor culverts. Minimum cover over proposed culverts will be a minimum of 12 inches from finished grade, which is assumed to match existing conditions.

2.4 Roadside Ditches

Roadside ditch flows and capacity are not being analyzed as part of this project.

2.5 Pavement Drainage

Existing drainage patterns will be maintained for the project. A minor increase in peak flow rates is anticipated from an increase in the proposed roadway width in Segment 1; however, this can be considered negligible and does not warrant increasing any facility sizes. Most pavement drainage will sheet flow off the roadway as there is no curb and gutter being proposed along the linear portion of project. Existing curb and gutter exist at the visitor’s center on the eastern side of the loop in Segment 2; however, no proposed changes are being made within impervious areas or the curb and gutter at this location.

2.6 Erosion Control

Temporary BMP’s, as shown in the standard Central Federal Lands Highway Division (CFLHD) details, will be used for control of erosion during construction. Placed riprap aprons will be used as a permanent erosion control measure at new culvert outfalls, including pipe extensions. Seeding will be used as permanent erosion control along disturbed embankments.

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2.7 Miscellaneous

The project is not within a mapped FEMA Floodplain. Neither a Conditional Letter of Map Revision (CLOMR) nor a Letter of Map Revision (LOMR) will be needed. Fish passage will not be accommodated since all streams crossing the roadway are ephemeral. Increases in impervious surfaces due to widening of the road will have a minimal increase in peak discharges; however, this increase in storm flow will be negligible, and thus, will not need to be mitigated through detention or retention.

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3. Hydrologic Analysis

3.1 Major Basin Analysis

There are no major basins discharging through the project that will require hydrologic analysis.

3.2 Minor Basin Analysis

The existing terrain varies throughout the project and consists of wooded areas, sage brush, and grasses. Aerial imagery, site reconnaissance, and NRCS soils information will be used to determine the appropriate time of concentration and runoff coefficients for use with the Rational Method in determining the flowrates at the proposed culvert at Montoso Campground. Precipitation values have been gathered from NOAA Atlas 14 data to develop intensity discharge frequency (IDF) curves.

The basin for the culvert at Montoso Campground was delineated using survey data and aerial photographs. The time of concentration was calculated using the velocity method; which is the combination of the sheet flow, shallow concentrated flow, and channel flow as described in HDS-2 Section 2.6.2. Time of concentration was calculated using the FHWA Hydraulic Toolbox. The rainfall intensity is then presented from the IDF curves at the basins calculated time of concentration.

The Rational Method (Q=CIA) was utilized for the hydrology for this project using the FHWA’s Hydraulic Toolbox utilizing the procedures from HDS-2. The output reports can be found in Appendix C for the basin tributary to the culvert north of Montoso Campground. Table 3.1 below summarizes the calculations.

Table 3.1: Hydrologic Summary - Montoso Campground

Basin ID Area (ac)

Runoff Coefficient

(C)

Rainfall Intensity (in/hr) Peak Storm Flow (cfs)

I2 I5 I10 I25 I50 Q2 Q5 Q10 Q25 Q50

CV45 13.75 0.25 0.92 1.25 1.52 1.92 2.24 3.2 4.3 5.3 6.7 7.8

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4. Hydraulic Analysis

4.1 Major Culverts

There are no major culverts that require hydraulic analysis for this project.

4.2 Minor Culverts

The culvert near Montoso Campground was analyzed using the FHWA’s HY8 computer program. The existing 21-inch by 15-inch culvert has the capacity to convey the 25-year and 50-year storm event flowrates without adversely affecting the road while meeting PDDM requirement for headwater to depth ratio. However, since there are observed sediment issues, and known drainage concerns, an increased pipe size will be proposed to allow for increased hydraulic performance. A 24-inch CMP is proposed to replace the existing culvert. There is adequate cover with the proposed culvert under the proposed roadway surface. The existing and proposed HY8 output for this culvert can be found in Appendix D and is summarized below in Tables 4.1.

Table 4.1: Montoso Campground Culvert Summary

Location 25-year

Design Flow (cfs)

Culvert Diameter

(D)(in)

Upstream Invert (feet)

Upstream

WSE

(feet)

HW/D

Outlet Depth (feet)

Outlet Velocity

(fps)

Existing CV45 6.7 21x15 Arch 7507.62 7509.14 1.22 0.81 5.20

Proposed CV45 6.7 24 7507.89 7509.28 0.70 0.80 5.70

The calculations show CV45 near Montoso Campground is outlet controlled.

Hydraulic analysis was not performed for any other culverts.

4.3 Culvert Material Selection

To be consistent with all other pipes within the project limits, corrugated metal pipe (CMP) will be used for cross culvert extensions and new culverts. New CMP pipes will match existing pipes in kind for thickness. No plastic pipe will be used for this project due to the potential damage from wildfire. No soil testing was performed for resistivity, pH, chloride and sulfate for this project. Minimum pipe gage should be per FWHA Customary Standard 602-1 as existing pipe are not experiencing any known corrosion issues, as seen during field investigations. However, the pavement design report indicated that corrosion risk is moderate to high. Corrosion mitigation measures that can be utilized are applying a layer of structural backfill or aggregate base course to separate native material, using galvanized or epoxy coatings, using cathodic protection, or using a heaver gauge steel. Since the project is a net import project, it is recommended to use structural backfill for new culverts to provide corrosion protection.

4.4 Curb Sections and Inlets

There is existing curb and gutter at the visitor center on the eastern loop that will remain. There is no proposed curb and gutter with this project; therefore, no proposed inlets will be required.

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4.5 Ditches

Ditches will maintain their existing flow patterns, capacity, and outlet locations; therefore, no ditch calculations have been performed. Any increases in storm flow from the widened roadway will be negligible. Widening of the roadway may cause a minimal reduction in ditch capacity on catch fill slopes. The proposed roadway grading will attempt to match the existing longitudinal grade and geometry to maintain existing ditch flow patterns. Any disturbed embankments due to roadway widening will be revegetated and protected with appropriate BMP’s as discussed in Section 6 of this report.

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5. Recommended Improvements

5.1 Existing Culverts

Existing culverts found to be in poor condition will be replaced in kind with an equivalent size and material to maintain existing flow patterns. Culverts in fair or good condition that require extension because of new roadway grading will be extended with an equivalent size pipe and material to the new toe of slope. An attempt was made during the field survey to identify the condition of culverts and end sections.

Poor condition is described as culverts, or end sections, that have significant dents, dings, corrosion, rust, holes, and/or deformation that is nearing or succeeded its design life. Photos of poor condition are representative below:

Culvert 32– Sta. 462+05

Culvert 52 – Sta. 646+61

Fair condition is described as culverts, or end sections, that have minor amounts of dents, dings, corrosion, rust, holes, and/or deformation but still have useful life and functionality. Photos of fair condition are representative below:

Culvert 29 – Sta. 429+95

Culvert 37 – Sta. 489+51

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Good condition is described as culverts, or end sections, that have minimal amounts of dents, dings, corrosion, rust, holes, and/or deformation and still have a significant useful life. Photos of good condition are representative below:

Culvert 39 – Sta. 520+64

Culvert 53 – 658+75

5.2 Proposed Culvert Improvements

Existing culvert pipes underneath the roadway will remain if found to be in fair or good condition and will be extended to the new toe of slope to match the proposed grading. Proposed culvert extensions will be short sections of pipe that will minimally impact the hydraulics of the culvert. The existing flared end sections (FES) will be removed with the new extensions being installed with an equivalent sized pipe and material. Connection details, erosion control plan sheets, and culvert cross sections can all be found in the plans.

End sections found to be in fair or poor condition will be replaced in kind throughout the project limits. End sections in good condition may be salvaged and reset after grading operations along with new riprap, or buried riprap, installed to mitigate erosion. Existing culverts to remain that are exhibiting silting or debris accumulations will be cleaned. These culverts were identified during the field survey. Refer to the culvert inventory in Appendix B for a list of culverts experiencing erosion and sedimentation issues.

Because some of the culverts within the project limits are exhibiting erosion, riprap will be placed at locations of existing culverts experiencing erosion and at locations of new culvert extensions. Riprap aprons have been sized using CFL standard drawing C251-50.

5.3 Montoso Campground Improvements

The culvert at Montoso Campground will be replaced with a larger 24-inch culvert to increase conveyance due to existing drainage concerns. The proposed culvert will meet PDDM requirements for size and hydraulic performance. This culvert will drain an area between the east leg and the west leg of the Segment 2 loop road that is experiencing observed sedimentation issues that warrant upsizing the pipe.

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6. Erosion and Sediment Control

6.1 Construction BMP’s

Fiber roll, riprap, or gravel bag check dams will be utilized in disturbed cut ditches and immediately upstream of existing and proposed culvert crossings to minimize the amount of sediment leaving the project within concentrated flows. Silt fencing or fiber rolls will be used at the base of disturbed slopes to minimize sediment leaving the project via sheet flow. To minimize soil tracking from project vehicles, stabilized construction exits will be used where construction traffic is leaving disturbed areas.

6.2 Permanent BMP’s

Proposed slopes in the project will be constructed at 1:4. Native seed and mulch mix will be applied by drilling and mulching for these slopes. Erosion control blankets will be placed on slopes equal to, or greater than, 1:3, or as needed at unstable locations. Seeding and mulching should be applied using drilling methods.

Some of the proposed culvert extensions outfall onto fill slopes. To protect the slope from erosion caused by concentrated flows, riprap protection will be used. Due to the number of existing culverts experiencing erosion, culverts that are being extended or replaced will have proposed riprap protection placed at the downstream ends of the culverts. Additional water quality mitigation measures are not proposed.

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7. References

• Hydraulic Design Series No. 2, Highway Hydrology, U.S. Department of Transportation Federal Highway Administration, second edition, October 2002.

• Hydraulic Design Series No. 5, Hydraulic Design of Highway Culverts, U.S. Department of Transportation Federal Highway Administration, third edition, January 2012.

• Hydraulic Engineering Circular No. 22, Urban Drainage Design Manual, U.S. Department of Transportation Federal Highway Administration, third edition, revised August 2013.

• FHWA Hydraulic Toolbox, U.S. Department of Transportation Federal Highway Administration, Version 4.4, July 10, 2018.

• Draft Final Pavement Report, NM FTBL 2004(1) Wild Rivers Back Country Byway, Yeh and Associates, Inc., June 15, 2020.

• HY-8, U.S. Department of Transportation Federal Highway Administration, Version 7.60, July 30, 2019.

Appendix A. FEMA FIRM Map

Entrance Road

Begin Loop Road (Project Limits)

Appendix B. Culvert Inventory

Wild Rivers Back Country Byway Appendix B

Culvert ID Station to Station Shape Span (in) Rise (in) Material Slope (%) Length (ft) Condition U/S Condition D/S Sediment U/S Sediment D/S Erosion U/S Erosion D/S Recommended Improvement Comments CV29 429+88 430+02 Circular 18 18 CMP-16G 1.47 40.24 Good Fair 1" to 2" 1" to 2" Minor Major Extended Full of branches D/S CV30 437+28 437+61 Pipe-Arch 21 15 CMP-16G 1.64 44.56 Fair Fair 1" to 2" 1" to 2" Major Major Extended CV31 448+86 448+86 Circular 18 18 CMP-16G 4.09 40.63 Fair Good 1" to 2" 1" to 2" Major Minor Extended CV32 462+04 462+05 Pipe-Arch 21 15 CMP-16G 2.08 42.73 Fair Poor 1" to 2" 1" to 2" Minor Minor Upsized to 24" CV33 464+00 464+05 Pipe-Arch 21 15 CMP-16G 2.33 42.49 Poor Poor 1" to 6" 1" to 6" Major Major Upsized to 24" CV34 465+12 465+72 Circular 12 12 CMP-16G 1.15 62.77 Poor Poor Full Full Major Major Upsized to 28"x20" CV35 470+15 470+84 Circular 21 15 CMP-16G 0.38 74.42 Fair Poor 1" to 2" 1" to 2" Minor Major Replaced with 18" Lots of branches U/S, smaller culvert insided biger culvert CV36 481+04 481+05 Circular 18 18 CMP-16G 1.71 44.54 Poor Fair 1" to 2" 1" to 2" Minor Major Extended Lots of branches U/S and D/S CV37 489+51 489+51 Circular 18 18 CMP-16G 5.58 46.65 Fair Fair 1" to 2" 1" to 2" Major Major Extended CV38 506+48 506+77 Pipe-Arch 21 15 CMP-16G 2.78 46.46 Fair Fair 1" to 2" 6" to 12" Minor Major Extended Full of branches D/S CV39 520+47 520+87 Circular 18 18 CMP-16G 3.77 52.77 Good Good 1" to 2" 1" to 2" Minor Minor Extended CV40 529+01 529+20 Pipe-Arch 21 15 CMP-16G 4.57 52.55 Good Good 1" to 2" None Minor Minor Extended CV41 532+55 532+61 Circular 18 18 CMP-16G 6.02 42.57 Fair Good 1" to 2" None Minor None Extended CV42 536+99 537+02 Circular 18 18 CMP-16G 7.18 56.97 Good Good 1" to 2" None Minor None Extended CV43 555+39 555+50 Pipe-Arch 21 15 CMP-16G 1.48 40.62 Poor Fair 6" to 12" 1" to 2" Major Minor Upsized to 24" Full of branches U/S CV44 559+24 559+25 Pipe-Arch 21 15 CMP-16G 1.01 38.68 Fair Fair 1" to 2" 1" to 2" Minor Minor Extended CV45 582+66 582+75 Pipe-Arch 21 15 CMP-16G 2.23 42.53 Poor Fair 1" to 2" 1" to 2" Major Major Upsized to 24" Full of branches U/S & D/S CV46 590+98 590+99 Pipe-Arch 21 15 CMP-16G 2.53 38.40 Fair Fair 1" to 2" 1" to 2" Minor Minor Extended CV47 602+45 602+51 Pipe-Arch 21 15 CMP-16G 3.55 38.64 Fair Fair 1" to 2" 1" to 2" Minor Major Upsized to 24" CV48 615+14 615+14 Pipe-Arch 28 20 CMP-16G 1.95 38.47 Fair Fair 1" to 2" 1" to 2" Minor Major Extended Full of branches D/S CV49 629+69 629+78 Circular 18 18 CMP-16G 2.70 38.54 Poor Fair 1" to 2" 1" to 2" Major Minor Extended Full of branches D/S CV50 636+80 636+92 Circular 30 30 CMP-16G 1.14 52.59 Poor Fair 1" to 2" 1" to 2" Minor Minor Replaced with 30" Full of branches D/S CV51 645+89 646+49 Circular 18 18 CMP-16G 1.75 60.01 Good Good 1" to 2" 1" to 2" Minor None N/A CV52 646+51 646+73 Circular 18 18 CMP-16G 0.99 42.48 Poor Poor 1" to 6" 1" to 6" Major Major Upsized to 28"x20" Full of branches U/S & D/S CV53 658+63 658+86 Circular 18 18 CMP-16G 1.43 42.78 Good Poor 1" to 6" None Major None Upsized to 24"

Culvert Inventory Survey Condition Assessment

Appendix C. Hydrologic Analysis

Wild Rivers Back County Byway Rainfall and Precipitation Data

5 10 15 30 60 5 10 15 30 60 2-yr 0.23 0.35 0.44 0.59 0.73 2.78 2.12 1.75 1.18 0.73 5-yr 0.32 0.48 0.60 0.80 0.99 3.78 2.89 2.38 1.60 0.99

10-yr 0.38 0.58 0.72 0.97 1.21 4.60 3.50 2.89 1.95 1.21 25-yr 0.48 0.73 0.91 1.22 1.52 5.78 4.40 3.64 2.44 1.52 50-yr 0.56 0.86 1.06 1.43 1.77 6.76 5.14 4.24 2.86 1.77

100-yr 0.65 0.99 1.23 1.66 2.05 7.84 5.96 4.92 3.32 2.05

St or m Duration (min)

Precipitation (in) Intensity (in/hr)

Hydraulic Analysis Report Project Data Project Title: NM Wild Rivers - Montoso Campground Hydrology Designer: David Bergh Project Date: February, 2020 Project Units: U.S. Customary Units Notes: Rational Analysis for proposed culvert near Montoso Campground.

Rational Analysis: Rational Method Analysis Notes:

Rational Method Input Parameters Runoff Coefficient: 0.25 Basin Area: 13.7500 acres Rainfall Intensity: 1.92 in/hr Time of Concentration: 42.92 minutes Recurrence Year: 25 year

Rational Method Results Flowrate: 6.7 cfs

IDF Input Parameters User Supplied Data 2 year Recurrence, 5 min duration: 2.78 in/hr 2 year Recurrence, 10 min duration: 2.12 in/hr 2 year Recurrence, 15 min duration: 1.75 in/hr 2 year Recurrence, 30 min duration: 1.18 in/hr 2 year Recurrence, 60 min duration: 0.73 in/hr 5 year Recurrence, 5 min duration: 3.78 in/hr 5 year Recurrence, 10 min duration: 2.89 in/hr 5 year Recurrence, 15 min duration: 2.38 in/hr 5 year Recurrence, 30 min duration: 1.6 in/hr 5 year Recurrence, 60 min duration: 0.99 in/hr 10 year Recurrence, 5 min duration: 4.6 in/hr 10 year Recurrence, 10 min duration: 3.5 in/hr 10 year Recurrence, 15 min duration: 2.89 in/hr 10 year Recurrence, 30 min duration: 1.95 in/hr 10 year Recurrence, 60 min duration: 1.21 in/hr 25 year Recurrence, 5 min duration: 5.78 in/hr 25 year Recurrence, 10 min duration: 4.4 in/hr 25 year Recurrence, 15 min duration: 3.64 in/hr 25 year Recurrence, 30 min duration: 2.44 in/hr 25 year Recurrence, 60 min duration: 1.52 in/hr 50 year Recurrence, 5 min duration: 6.76 in/hr 50 year Recurrence, 10 min duration: 5.14 in/hr 50 year Recurrence, 15 min duration: 4.24 in/hr 50 year Recurrence, 30 min duration: 2.86 in/hr 50 year Recurrence, 60 min duration: 1.77 in/hr 100 year Recurrence, 5 min duration: 7.84 in/hr 100 year Recurrence, 10 min duration: 5.96 in/hr 100 year Recurrence, 15 min duration: 4.92 in/hr 100 year Recurrence, 30 min duration: 3.32 in/hr 100 year Recurrence, 60 min duration: 2.05 in/hr

IDF Results 25 year IDF equation: i = 45.747 / (Tc + 8.08009)^0.80636 Intensity: 1.9205 in/hr

Time of Concentration Input Parameters Minimum Time of Concentration: 5.00 min

Computed Time of Concentration Time of Concentration: 42.92 min

Sheet Flow Input Parameters Top Elevation: 7535.00 ft Bottom Elevation: 7530.00 ft Length: 100.00 ft

Recommended length not to exceed 100'. Maximum length is 300' Manning's n: 0.2400

See HDS-2 Table 2.1 2 yr, 24 hr precip: 1.2500 in

Sheet Flow Results Slope: 0.0500 ft/ft Time of Concentration: 15.83 min

Shallow Concentrated Flow Input Parameters Top Elevation: 7530.00 ft Bottom Elevation: 7512.70 ft Length: 1550.00 ft k: 0.3050

See HDS-2 Table 2.2

Shallow Concentrated Flow Results Slope: 0.0112 ft/ft Velocity: 1.0633 ft/s

HDS-2 equation 2.7 Time of Concentration: 24.29 min

Channel Flow Input Parameters Define as: Channel Calculation Channel Name: Channel Analysis Top Elevation: 7512.70 ft Bottom Elevation: 7507.51 ft

Length: 510.00 ft Manning's n: 0.0250

Channel Flow Results Slope: 0.0102 ft/ft Velocity: 3.0311 ft/s

Determined by Channel or Curb & Gutter Calculator Time of Concentration: 2.80 min

Total Time of Concentration

Time of Concentration: 42.92 min Final Iterated Solution

Report for channel used in Time of Concentration calculations

Channel Analysis: Channel Analysis Notes:

Input Parameters Channel Type: Triangular Side Slope 1 (Z1): 4.0000 ft/ft

Side Slope 2 (Z2): 4.0000 ft/ft Longitudinal Slope: 0.0102 ft/ft Manning's n: 0.0250 Flow: 6.6567 cfs

Result Parameters Depth: 0.7410 ft

Area of Flow: 2.1961 ft^2 Wetted Perimeter: 6.1101 ft Hydraulic Radius: 0.3594 ft Average Velocity: 3.0311 ft/s

Top Width: 5.9277 ft Froude Number: 0.8776 Critical Depth: 0.7033 ft Critical Velocity: 3.3649 ft/s

Critical Slope: 0.0134 ft/ft Critical Top Width: 5.63 ft Calculated Max Shear Stress: 0.4705 lb/ft^2 Calculated Avg Shear Stress: 0.2282 lb/ft^2

Hydrograph - Rational - Rational Hydrograph Method 25 year recurrence Interval, Peak Discharge: 6.193 cfs, Time to Peak: 6.00 (min), Total Volume: 2170.73 ft^3

Time (minutes) Flow cfs

0.00 0.00

1.00 0.97

2.00 1.93

3.00 2.90

4.00 3.87

5.00 4.83

6.00 6.19

7.00 5.16

8.00 4.13

9.00 3.10

10.00 2.06

11.00 1.03

12.00 0.00

Hydraulic Analysis Report Project Data Project Title: NM Wild Rivers - Montoso Campground Hydrology Designer: David Bergh Project Date: February6, 2020 Project Units: U.S. Customary Units Notes: Rational Analysis for proposed culvert near Montoso Campground.

Rational Analysis: Rational Method Analysis

Rational Method Input Parameters Runoff Coefficient: 0.25 Basin Area: 13.7500 acres Rainfall Intensity: 2.24 in/hr Time of Concentration: 42.82 minutes Recurrence Year: 50 year

Rational Method Results Flowrate: 7.8 cfs

IDF Input Parameters User Supplied Data 2 year Recurrence, 5 min duration: 2.78 in/hr 2 year Recurrence, 10 min duration: 2.12 in/hr 2 year Recurrence, 15 min duration: 1.75 in/hr 2 year Recurrence, 30 min duration: 1.18 in/hr 2 year Recurrence, 60 min duration: 0.73 in/hr 5 year Recurrence, 5 min duration: 3.78 in/hr 5 year Recurrence, 10 min duration: 2.89 in/hr 5 year Recurrence, 15 min duration: 2.38 in/hr 5 year Recurrence, 30 min duration: 1.6 in/hr 5 year Recurrence, 60 min duration: 0.99 in/hr 10 year Recurrence, 5 min duration: 4.6 in/hr 10 year Recurrence, 10 min duration: 3.5 in/hr 10 year Recurrence, 15 min duration: 2.89 in/hr 10 year Recurrence, 30 min duration: 1.95 in/hr 10 year Recurrence, 60 min duration: 1.21 in/hr 25 year Recurrence, 5 min duration: 5.78 in/hr 25 year Recurrence, 10 min duration: 4.4 in/hr 25 year Recurrence, 15 min duration: 3.64 in/hr 25 year Recurrence, 30 min duration: 2.44 in/hr 25 year Recurrence, 60 min duration: 1.52 in/hr 50 year Recurrence, 5 min duration: 6.76 in/hr 50 year Recurrence, 10 min duration: 5.14 in/hr 50 year Recurrence, 15 min duration: 4.24 in/hr 50 year Recurrence, 30 min duration: 2.86 in/hr 50 year Recurrence, 60 min duration: 1.77 in/hr 100 year Recurrence, 5 min duration: 7.84 in/hr 100 year Recurrence, 10 min duration: 5.96 in/hr 100 year Recurrence, 15 min duration: 4.92 in/hr 100 year Recurrence, 30 min duration: 3.32 in/hr 100 year Recurrence, 60 min duration: 2.05 in/hr

IDF Results 50 year IDF equation: i = 49.5322 / (Tc + 7.47373)^0.789777 Intensity: 2.2443 in/hr

Time of Concentration Input Parameters Minimum Time of Concentration: 5.00 min

Computed Time of Concentration Time of Concentration: 42.82 min

Sheet Flow Input Parameters Top Elevation: 7535.00 ft Bottom Elevation: 7530.00 ft Length: 100.00 ft

Recommended length not to exceed 100'. Maximum length is 300' Manning's n: 0.2400

See HDS-2 Table 2.1 2 yr, 24 hr precip: 1.2500 in

Sheet Flow Results Slope: 0.0500 ft/ft Time of Concentration: 15.83 min

Shallow Concentrated Flow Input Parameters Top Elevation: 7530.00 ft Bottom Elevation: 7512.70 ft Length: 1550.00 ft k: 0.3050

See HDS-2 Table 2.2

Shallow Concentrated Flow Results Slope: 0.0112 ft/ft Velocity: 1.0633 ft/s

HDS-2 equation 2.7 Time of Concentration: 24.29 min

Channel Flow Input Parameters Define as: Channel Calculation Channel Name: Channel Analysis Top Elevation: 7512.70 ft Bottom Elevation: 7507.51 ft

Length: 510.00 ft Manning's n: 0.0250

Channel Flow Results Slope: 0.0102 ft/ft Velocity: 3.1515 ft/s

Determined by Channel or Curb & Gutter Calculator Time of Concentration: 2.70 min

Total Time of Concentration Time of Concentration: 42.82 min Final Iterated Solution

Report for channel used in Time of Concentration calculations

Channel Analysis: Channel Analysis

Input Parameters Channel Type: Triangular Side Slope 1 (Z1): 4.0000 ft/ft

Side Slope 2 (Z2): 4.0000 ft/ft Longitudinal Slope: 0.0102 ft/ft Manning's n: 0.0250 Flow: 7.7792 cfs

Result Parameters Depth: 0.7856 ft

Area of Flow: 2.4684 ft^2 Wetted Perimeter: 6.4778 ft Hydraulic Radius: 0.3810 ft Average Velocity: 3.1515 ft/s

Top Width: 6.2844 ft Froude Number: 0.8862 Critical Depth: 0.7485 ft Critical Velocity: 3.4714 ft/s

Critical Slope: 0.0132 ft/ft Critical Top Width: 5.99 ft Calculated Max Shear Stress: 0.4988 lb/ft^2 Calculated Avg Shear Stress: 0.2420 lb/ft^2

Hydrograph - Rational - Rational Hydrograph Method 50 year recurrence Interval, Peak Discharge: 6.193 cfs, Time to Peak: 6.00 (min), Total Volume: 2170.73 ft^3

Time (minutes) Flow cfs

0.00 0.00

1.00 0.97

2.00 1.93

3.00 2.90

4.00 3.87

5.00 4.83

6.00 6.19

7.00 5.16

8.00 4.13

9.00 3.10

10.00 2.06

11.00 1.03

12.00 0.00

Appendix D. Hydraulic Analysis

HY-8 Culvert Analysis Report – CV45-EX Crossing Discharge Data

Discharge Selection Method: Recurrence

Table 1 - Summary of Culvert Flows at Crossing: NMWR-EX

Headwater Elevation (ft) Discharge Names Total Discharge

(cfs)

CV45-EX21-15

Discharge (cfs)

Roadway Discharge (cfs) Iterations

7508.49 2 year 3.20 3.20 0.00 1

7508.66 5 year 4.30 4.30 0.00 1

7508.83 10 year 5.30 5.30 0.00 1

7509.14 25 year 6.70 6.70 0.00 1

7509.40 50 year 7.80 7.80 0.00 1

7511.47 Overtopping 12.50 12.50 0.00 Overtopping

Rating Curve Plot for Crossing: NMWR-EX

Table 2 - Culvert Summary Table: CV45-EX21-15

Discharge Names

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) 2 year 3.20 3.20 7508.49 0.869 0.0* 1-S2n 0.496 0.533 0.496 0.565 4.226 2.507 5 year 4.30 4.30 7508.66 1.039 0.109 1-S2n 0.598 0.631 0.598 0.631 4.595 2.700 10 year 5.30 5.30 7508.83 1.210 0.411 1-S2n 0.691 0.711 0.691 0.682 4.849 2.845 25 year 6.70 6.70 7509.14 1.502 1.516 7-M2c 0.829 0.813 0.813 0.745 5.195 3.016 50 year 7.80 7.80 7509.40 1.776 1.674 7-M2c 0.959 0.885 0.885 0.789 5.584 3.133

* Full Flow Headwater elevation is below inlet invert.

Straight Culvert

Inlet Elevation (invert): 7507.62 ft, Outlet Elevation (invert): 7506.67 ft

Culvert Length: 42.20 ft, Culvert Slope: 0.0225

Culvert Performance Curve Plot: CV45-EX21-15

Water Surface Profile Plot for Culvert: CV45-EX21-15

Site Data - CV45-EX21-15 Site Data Option: Culvert Invert Data Inlet Station: 0.00 ft Inlet Elevation: 7507.62 ft Outlet Station: 42.19 ft

Outlet Elevation: 7506.67 ft Number of Barrels: 1

Culvert Data Summary - CV45-EX21-15 Barrel Shape: Pipe Arch Barrel Span: 21.00 in Barrel Rise: 15.00 in

Barrel Material: Steel or Aluminum Embedment: 0.00 in Barrel Manning's n: 0.0250 Culvert Type: Straight

Inlet Configuration: Mitered Inlet Depression: None

Table 3 - Downstream Channel Rating Curve (Crossing: NMWR-EX)

Tailwater Channel Data - NMWR-EX Tailwater Channel Option: Triangular Channel Side Slope (H:V): 4.00 (_:1) Channel Slope: 0.0100

Channel Manning's n: 0.0250 Channel Invert Elevation: 7506.67 ft

Roadway Data for Crossing: NMWR-EX Roadway Profile Shape: Constant Roadway Elevation Crest Length: 10.00 ft Crest Elevation: 7511.47 ft

Roadway Surface: Paved Roadway Top Width: 23.00 ft

Flow (cfs) Water Surface Elev (ft) Depth (ft) Velocity (ft/s) Shear (psf) Froude Number

3.20 7507.23 0.56 2.51 0.35 0.83

4.30 7507.30 0.63 2.70 0.39 0.85

5.30 7507.35 0.68 2.84 0.43 0.86

6.70 7507.42 0.75 3.02 0.47 0.87

7.80 7507.46 0.79 3.13 0.49 0.88

HY-8 Culvert Analysis Report – CV45-Prop Crossing Discharge Data

Discharge Selection Method: Recurrence

Table 1 - Summary of Culvert Flows at Crossing: NMWR-PR

Headwater Elevation (ft) Discharge Names Total Discharge

(cfs)

CV45-PR24

Discharge (cfs) Roadway

Discharge (cfs) Iterations

7508.80 2 year 3.20 3.20 0.00 1

7508.96 5 year 4.30 4.30 0.00 1

7509.10 10 year 5.30 5.30 0.00 1

7509.28 25 year 6.70 6.70 0.00 1

7509.42 50 year 7.80 7.80 0.00 1

7511.60 Overtopping 21.29 21.29 0.00 Overtopping

Rating Curve Plot for Crossing: NMWR-PR

Table 2 - Culvert Summary Table: CV45-PR24

Discharge Names

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) 2 year 3.20 3.20 7508.80 0.908 0.0* 1-S2n 0.543 0.625 0.543 0.565 4.640 2.507 5 year 4.30 4.30 7508.96 1.068 0.0* 1-S2n 0.632 0.728 0.632 0.631 5.045 2.700 10 year 5.30 5.30 7509.10 1.206 0.0* 1-S2n 0.706 0.812 0.706 0.682 5.347 2.845 25 year 6.70 6.70 7509.28 1.390 0.0* 1-S2n 0.801 0.917 0.801 0.745 5.700 3.016 50 year 7.80 7.80 7509.42 1.529 0.0* 1-S2n 0.871 0.993 0.871 0.789 5.935 3.133

* Full Flow Headwater elevation is below inlet invert.

Straight Culvert

Inlet Elevation (invert): 7507.89 ft, Outlet Elevation (invert): 7506.25 ft

Culvert Length: 62.89 ft, Culvert Slope: 0.0261

Culvert Performance Curve Plot: CV45-PR24

Water Surface Profile Plot for Culvert: CV45-PR24

Site Data - CV45-PR24 Site Data Option: Culvert Invert Data Inlet Station: 0.00 ft Inlet Elevation: 7507.89 ft Outlet Station: 62.87 ft

Outlet Elevation: 7506.25 ft Number of Barrels: 1

Culvert Data Summary - CV45-PR24 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 Inlet Configuration: Thin Edge Projecting

Inlet Depression: None

Table 3 - Downstream Channel Rating Curve (Crossing: NMWR-PR)

Tailwater Channel Data - NMWR-PR Tailwater Channel Option: Triangular Channel Side Slope (H:V): 4.00 (_:1) Channel Slope: 0.0100

Channel Manning's n: 0.0250 Channel Invert Elevation: 7506.25 ft

Roadway Data for Crossing: NMWR-PR Roadway Profile Shape: Constant Roadway Elevation Crest Length: 10.00 ft Crest Elevation: 7511.60 ft

Roadway Surface: Paved Roadway Top Width: 23.00 ft

Flow (cfs) Water Surface Elev (ft) Depth (ft) Velocity (ft/s) Shear (psf) Froude Number

3.20 7506.81 0.56 2.51 0.35 0.83

4.30 7506.88 0.63 2.70 0.39 0.85

5.30 7506.93 0.68 2.84 0.43 0.86

6.70 7507.00 0.75 3.02 0.47 0.87

7.80 7507.04 0.79 3.13 0.49 0.88