FINAL-HYDReport-NMFTBL2004(2)(3)WildRiver.pdf

Final Hydraulics Report

NM FTBL 2004(2)

Wild Rivers Back County Byway – Phases 2 & 3

Prepared for:

Federal Highway Administration

Central Federal Lands Highway Division

12300 West Dakota Avenue

Lakewood, CO 80228

August 2023

(Revised December 2023)

Prepared By:

Jacobs Engineering Group

6312 S. Fiddlers Green Circle

Suite 300N

Greenwood Village, CO 80111

12/14/2023

Wild Rivers Back Country Byway - Phase 2 & 3 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 Proposed Ditch Lining

6. Erosion and Sediment Control

6.1 Construction BMP’s

6.2 Permanent BMP’s

7. References

Wild Rivers Back Country Byway - Phase 2 & 3 ii

List of Figures

Figure 1.1: Vicinity Map

List of Tables

Table 3-1. Runoff Coefficients Table 4.1: Montoso Campground Culvert Summary Table 4-1. Ditch Lining Summary

List of Appendices

Appendix A. Maps and Figures

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

CFS Cubic Feet per Second

CLOMR Conditional Letter of Map Revision

DEM Digital Elevation Model

FEMA Federal Emergency Management Agency

FES Flared End Section

FPS Feet per Second

FIRM Flood Insurance Rate Map

FT Feet

GIS Geographics Informations System

HDS Hydraulic Design Series

HEC Hydraulic Engineering Circular

HW/D Headwater Depth per Diameter

LOMR Letter of Map Revision

MP Milepost

PPDM Project Development and Design Manual

RECP Rolled Erosion Control Product

SR State Route

WSE Water Surface Elevation

Wild Rivers Back Country Byway – Phase 2 & 3 Page | 1

1. Introduction and Purpose

This Draft Final Hydraulics 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 BCB. Construction of the Loop Road improvements was completed in 2022. This Draft Final

Hydraulics Report describes the Entrance Road improvements.

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 1.1 – 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 were constructed as Phase 1 with Segment 1 being constructed as part of

Phase 2 and Phase 3. Phase 2 will include construction of roadway and drainage improvements from Ice Hill to the completed Phase 1 Loop Road improvements. Phase 3 will be constructed with a future project including roadway and drainage improvements that will connect to the limits of Phase 2 with the entrance to the park for Segment 1.

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 replacements in several areas.

Culvert cleaning.

Replace / install culverts.

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.

Wild Rivers Back Country Byway – Phase 2 & 3 Page | 2

Reset guardrail to meet safety standards.

Figure 1.1: Vicinity Map

1.2.2 Segment 2

The following improvements were completed 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.

Phase 2 Limits

Phase 1 Limits

Phase 3 Limits

Ice Hill

Wild Rivers Back Country Byway – Phase 2 & 3 Page | 3

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 were completed 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

Refer to the Final Hydraulics Report by Jacobs dated July 2020, for Phase1 analyses and discussions of the Loop

Road (Segment 2) and other area (Segment 3) improvements. No known previous studies were identified within

Phase 2 and 3 (Segment 1) project limits.

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 is included in Appendix B.

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. No wetlands were observed within the project limits. 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.

Wild Rivers Back Country Byway – Phase 2 & 3 Page | 4

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 is replacing and upsizing existing culverts. Culverts smaller than 24-inches will be replaced with the larger 24-inch culvert or equivalent sized pipe. Where cover does not facilitate a 24-inch pipe, multiple barrels of an 18-inch or equivalent will be used. Culverts within the project limits require no hydrologic or hydraulic analysis since there isn’t any known overtopping or safety concerns with the existing culverts. This was confirmed through the initial walkthrough of the project with CFLHD and Jacobs staff.

Existing capacities of culverts and ditches will be maintained with the proposed project. The following sections describe the criteria that will be used for the project.

2.2 Hydrologic Analysis

The Rational Method, following the procedures described in HDS-2, is being used where the tributary area is less than 200 acres. Hydrologic analyses were completed to calculate flows to the roadside ditches and one new culvert location at Guadalupe Trail. Flowrates for the ditches were calculated for the 10-year storm event per PDDM

Chapter 7, Exhibit 7.1-A with the new culvert being sized to convey the 25-year flood. For this project, all hydrologic calculations were completed with FHWA’s Hydraulic Toolbox Version 5.2 Rational Method Analysis routine. All culverts will be replaced in kind dependent upon condition. No hydrologic or hydraulic analyses were completed for existing culvert crossings.

2.3 Hydraulic Analysis

Hydraulic analysis for the project was primarily limited to ditch flow calculations only as the existing culverts are to be replaced in kind. Culverts that are to be replaced will be done so with equivalent sized pipe and material with a minimum slope of the existing culvert to maintain existing capacity. One new culvert is required at the Guadalupe

Trail access. The hydraulics analysis of this culvert 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 capacities were analyzed using Manning’s Equation through FHWA’s Hydraulic Toolbox

Version 5.2 Channel Analysis routine. Shear stresses were calculated using the Channel Lining Design Analysis routine. Results can be found in Appendix D.

2.5 Pavement Drainage

Existing drainage patterns will be maintained for the project. A negligible increase in peak flowrates is anticipated from the proposed additional roadway width; 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 the project.

Wild Rivers Back Country Byway – Phase 2 & 3 Page | 5

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. Temporary erosion control plans have not been provided. Placed riprap aprons will be used as a permanent erosion control measure at new culvert outfalls.

2.7 Miscellaneous

The project is not located within a mapped FEMA Floodplain, therefore, 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.

Wild Rivers Back Country Byway – Phase 2 & 3 Page | 6

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 Rational Method Analysis routine was used within the FHWA’s Hydraulic Toolbox to determine flowrates for each roadside ditch. Only flows tributary to roadside ditches were analyzed. The Rational Method (Q=CIA) is limited to basins of less than 200 acres per PDDM Chapter 7.2.4.1.1. ArcGIS version 10.8.2 was used to aid in providing the required input parameters to complete the hydrologic analyses.

Flows directly tributary to a culvert via ephemeral stream beds, natural swales, or other drainage conveyances not directly tributary to a ditch were not analyzed. Calculations and results stated in this report relate only to the flows tributary to the ditches.

3.2.1 Land Coverage

The existing terrain varies throughout the project and consists of paved areas, steep heavy wooded areas, and high prairie areas with minimal existing development. Aerial imagery, site reconnaissance, and NRCS soils information was used to determine the appropriate runoff coefficients for use within the Rational Method. ArcGIS was used to develop a composite runoff coefficient for each basin. The runoff coefficients (C) used for this project are described in Table 3-1:

Table 3-1. Runoff Coefficients

Land Coverage Description Runoff Coefficient (C)

Paved Areas 0.90

Prairie Areas 0.20

Steep Heavy Wooded Areas / Embankments 0.25

3.2.2 Basin Delineation

The aerial topography and survey that Jacobs completed for the project discussed in Section 1.4 is limited to about a 100-foot swath centered on the roadway; therefore, additional topography was required to delineate basins. Each subbasin’s area (A) tributary to the roadside ditches was delineated in ArcGIS using a 10-meter (33-feet) digital elevation model (DEM). The DEM was imported from the U.S. Geological Service as Jacobs was unable to locate higher resolution data for the area.

Additionally, the centroid of the subbasin was converted into a latitude and longitude within ArcGIS. This information was then used as input to determine the precipitation values. Offsite and onsite ditch subbasin maps were created and added to Appendix A with the hydrological calculations added to Appendix C. In addition, a summary table of calculated flowrates can be found in Appendix C.

Offsite ditch subbasins are considered basins tributary the ditch that feature large offsite areas associated with them typically occurring to the east side of the roadway centerline. Onsite basins are much smaller that are made up of smaller areas with roadway asphalt surfacing and the embankment. The onsite basins are typically located to the west of the roadway centerline. Both offsite and onsite basin calculations were completed to check for ditch capacity and required channel lining.

Wild Rivers Back Country Byway – Phase 2 & 3 Page | 7

3.2.3 Precipitation

Rainfall Intensities (I) were obtained from NOAA Atlas 14 data to develop intensity discharge frequency (IDF) curves. Rainfall intensity for each basin was then derived from the IDF curves based on calculated times of concentration. IDF curves were directly extrapolated from NOAA within the Hydraulic Toolbox with the basin centroid latitude and longitude developed within ArcGIS.

3.2.4 Time of Concentration

The times of concentration were 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 using the FHWA’s Hydraulic

Toolbox.

3.2.5 Peak Flowrate Calculations

Using the parameters discussed in Section 3.2, peak flowrates were calculated for ditches within the Hydraulic

Toolbox. A hydrologic summary and output report for each basin can be found in Appendix C for the basin’s tributary to the ditches and the culvert at Guadalupe Trail.

Wild Rivers Back Country Byway – Phase 2 & 3 Page | 8

4. Hydraulic Analysis

4.1 Major Culverts

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

4.2 Minor Culverts

A new culvert is required at the Guadalupe Trail access and 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. The proposed

HY8 output for this culvert can be found in Appendix D and is summarized below in Table 4.1.

Table 4.1: Guadalupe Access 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)

165+05 L 4.8 21x15 Arch 7475.50 7473.00 0.91 0.52 4.43

4.3 Culvert Material Selection

To be consistent with all other pipes within the project limits, corrugated metal pipe (CMP) will be used for 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 pipes 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 include installing a layer of aggregate base course to separate native material, galvanized or epoxy coatings, cathodic protection, or 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 no proposed curb and gutter with this project; therefore, no proposed inlets will be required.

4.5 Ditches

Widening of the roadway may cause a reduction in existing ditch capacities if just a fill slope is added. A proposed ditch section will be added in fill slope locations to convey flows to existing culverts. Using the design flowrates developed in Section 3 of this report, hydraulic analyses were performed that evaluate capacity and erosive potential. Hydraulic capacities of the existing and proposed ditches were analyzed using the Channel Analysis routine within the Hydraulic Toolbox utilizing Manning’s Equation for the minimum ditch slope. Proposed ditches were designed so that the capacities are not reduced when compared to existing.

Hydraulic shear stresses were calculated for the existing and proposed ditches and calculations were completed using the Channel Lining Design Analysis routine within the Hydraulic Toolbox. Analyzing the existing ditch, not only for capacity, but for existing shear stresses, allows for more comprehensive identification of inadequate existing roadside ditches. The existing ditch shear stresses were analyzed using a “fair” vegetative condition.

Proposed ditch lining sections were analyzed using the same routine to determine the maximum shear stress in

Wild Rivers Back Country Byway – Phase 2 & 3 Page | 9 the ditch section. Proposed channel linings are based on the maximum shear stress calculated and compared to tables 713-3 and 713-4 in the Standard Specifications (FP-14). Proposed ditch linings can be summarized with the following relationship of shear stresses at maximum ditch slopes per ditch section.

• Vegetation: 0-0.25 pounds per square foot

• Rolled Erosion Control Products (RECP) (Classes used 2.C, 2.D, and 4) – Erosion Control Blankets: 0.25-

2.25 pounds per square foot

• RECP – Turf Reinforcement Mats (Class used 5A): 2.25-10 pounds per square foot

• Riprap: 10+ pounds per square foot

Project type requires that proposed ditches meet or exceed the capacity of the existing ditch but do not require providing additional freeboard. Proposed ditches will be lined using the recommendations discussed herein and as shown in Table 4-2 below. Ditches that only require vegetation lining are not included below as the project will be reseeded in all disturbed areas per the specifications.

Table 4-2. Ditch Lining Summary

Beginning

Station

Ending

Station Offset Subbasin ID Q10 (cfs)

Shear Stress

@ Min Slope

(lb/ft2)

Shear Stress

@ Max Slope

(lb/ft2)

Lining†

Type & Class

12+50 37+22 L ON1 36.1 0.52 0.92 RECP – 2.C

37+22 50+75 L ON2 18.2 0.22 0.81 RECP – 2.C

50+75 57+83 L ON3 3.0 0.06 0.41 RECP – 2.C

57+83 79+61 L ON4 34.4 1.19 2.09 RECP – 4

79+61 98+46 L ON5 6.5 0.58 1.55 RECP – 2.D

98+46 112+56 L ON6 6.2 0.26 0.54 RECP – 2.C

112+56 119+96 L ON7 1.1 0.28 0.59 RECP – 2.C

119+96 138+07 L ON8 1.7 0.13 0.44 RECP – 2.C

138+07 144+42 L ON9 0.6 0.13 0.50 RECP – 2.C

144+42 159+50 L ON10 1.8 0.22 0.47 RECP – 2.C

159+50 170+90 L ON11 18.3 0.81 1.98 RECP – 4

161+80 167+60 R 167R 1.4 1.18 1.18 RECP – 2.C

176+75 184+63 L ON12 1.2 0.34 0.99 RECP – 2.C

170+90 176+75 L ON13 2.8 0.50 1.11 RECP – 2.C

184+63 191+51 L ON14 6.0 1.09 1.41 RECP – 2.C

191+51 196+27 L ON37 0.5 0.21 0.65 RECP – 2.C

197+46 199+24 L ON36 0.5 0.34 0.34 RECP – 2.C

199+24 201+33 L ON15 0.9 0.55 1.42 RECP – 2.C

201+33 212+49 L ON17 3.3 0.75 1.39 RECP – 2.C

Wild Rivers Back Country Byway – Phase 2 & 3 Page | 10

Beginning

Station

Ending

Station Offset Subbasin ID Q10 (cfs)

Shear Stress

@ Min Slope

(lb/ft2)

Shear Stress

@ Max Slope

(lb/ft2)

Lining†

Type & Class

212+49 217+50 L ON18 18.2 1.12 2.49 RECP – 5.A

217+50 220+35 L ON16 2.2 0.24 0.37 RECP – 2.C

220+35 234+19 L ON19 3.0 0.41 1.09 RECP – 2.C

234+19 243+77 L ON20 4.9 0.87 1.43 RECP – 2.C

243+77 252+99 L ON21 1.0 0.48 1.48 RECP – 2.C

253+06 279+17 L ON22 2.3 0.52 2.42 RECP – 5.A

274+80 281+25 R 275R 2.0 0.55 1.15 RECP – 4

280+39 308+40 L ON23 3.2 0.55 0.92 RECP – 2.C

308+52 319+50 L ON24 2.0 0.26 0.86 RECP – 2.C

320+50 348+04 L ON25 3.0 0.16 0.72 RECP – 2.C

352+35 363+65 L ON26 6.5 0.55 1.16 RECP – 2.C

366+74 374+61 L ON29 3.2 0.32 0.97 RECP – 2.C

375+97 388+71 L ON31 1.5 0.15 0.51 RECP – 2.C

388+83 396+75 L ON32 2.2 0.21 0.70 RECP – 2.C

398+24 404+27 L ON33 0.8 0.21 0.44 RECP – 2.C

406+92 412+74 L ON34 1.4 0.38 0.65 RECP – 2.C

412+91 418+00 L ON35 5.2 0.67 1.40 RECP – 2.C

† Where RECP equals Rolled Erosion Control Product and type per Standard Specification (FP-14) Tables 713-3 and 713-4.

Wild Rivers Back Country Byway – Phase 2 & 3 Page | 11

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. Existing culverts that are 18-inches in diameter, or smaller, will be replaced with

24-inch diameter, or equivalent, where site conditions allow. Where there is insufficient cover to achieve this, the culverts will be replaced in-kind with a parallel culvert of same type and size added either up-station or down-station, as indicated on the plans. An attempt was made during the field survey to identify the condition of culverts and end sections to determine which culverts should be extended and which should be replaced. The initial guideline was that culverts in fair or good condition would be extended and culverts in poor condition would be replaced. CFLHD requested during final design that all culverts be replaced. The culvert condition descriptions below remain in the Final Hydraulics Report for informational and documentation purposes.

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 representing poor condition are provided below:

Culvert 12 – Sta. 137+93

Culvert 14– Sta. 144+44

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 representing fair condition are provided below:

Culvert 6 – Sta. 50+76

Culvert 18 – Sta. 197+44

Wild Rivers Back Country Byway – Phase 2 & 3 Page | 12

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 representing good condition are provided below:

Culvert 9 – Sta. 98+45

Culvert 20 – 253+14

5.2 Proposed Culvert Improvements

All existing pipes underneath the roadway will be removed and replaced to match the proposed roadway grading.

Proposed culvert slopes will be equal to or greater than existing, where possible, to maintain, at a minimum, the existing hydraulics of the culvert. The existing flared end sections (FES) will be removed and replaced with new.

Riprap will be placed at the outfalls of all new culverts. Where erosion was observed at the inlets to existing culverts, riprap was designated to be placed at the inlets of new culverts at those locations. Riprap aprons will be sized per

Standard Drawing C251-50.

5.3 Proposed Ditch Lining

Proposed ditch linings are discussed in Section 4.5 and are shown in the construction drawings.

Wild Rivers Back Country Byway – Phase 2 & 3 Page | 13

6. Erosion and Sediment Control

6.1 Construction BMPs

Fiber roll, riprap, or gravel bag check dams should be utilized in disturbed cut ditches and immediately upstream of existing and proposed culvert crossings to minimize the amount of sediment leaving the project via concentrated flow. Silt fencing or fiber rolls should 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. Temporary erosion control BMPs will not be shown on the plans and will be part of the requirements for the contractor to provide locations and temporary erosion control BMPs as part of the Storm Water Pollution Prevention Plan.

6.2 Permanent BMPs

Proposed roadway fore-slopes in the project will be constructed at 1:4 while back-slopes will be generally constructed at 1:3. Back-slopes may be cut steeper in rock cut areas up to a maximum of 1:2 slope. Native seed and mulch mix will be applied by drill seeding and dry application methods. Rolled Erosion Control Product (RECP) will be placed along cut ditches and toe of fill slopes where shown on the plans. No RECP will be used in rock cut areas. Seeding and mulching shall be applied using drilling methods.

Some proposed culverts will 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 will have proposed riprap or buried riprap. Additional water quality mitigation measures are not proposed.

Wild Rivers Back Country Byway – Phase 2 & 3 Page | 14

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. 14, Hydraulic Design of Energy Dissipators for Culverts and Channels, U.S. Department of Transportation Federal Highway Administration, third edition, July 2006.

• 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 5.2, October 18, 2022.

• ArcGIS Desktop, Esri Inc., Version 10.8.2, 2021.

• USGS 1/3 Arc Second n37w106 20220801 Digital Elevation Model, U.S. Geological Survey, August 1, 2022.

• Final Hydraulics Report - NM FTBL 2004(1) Wild Rivers Back Country Byway, Jacobs Engineering Group, July 2020.

Appendix A. Maps and Figures

A.1 FEMA FIRM Map

A.2 FEMA FIRM Map

A.3 Offsite Ditch Subbasin Map

A.4 Onsite Ditch Subbasin Map Sheet 1

A.5 Onsite Ditch Subbasin Map Sheet 2

A.6 Onsite Ditch Subbasin Map Sheet 3

Project Limits

FIGURE A.1

Project Limits

FIGURE A.2

FIGURE A.3

TRIBUTARY DITCHES

OFFSITE SUBBASIN MAP

PN:

g e c k o

\T B

G \C

F L

N

M -W ild R iv e r\

-D e s ig n \3

H y d ra u lic \4

D e s ig n \G

IS

\S u b b a s in

M a p .m x d

DATE: 11/16/2023

LOCATOR MAP

CREATED BY:

REVIEWED BY:

CV37

CV26

CV25

CV23/24

CV38/39

CV35/36

CV33/34

CV31/32

CV29/30

CV27/28

ON26

ON20

ON35

O N

O N

ON29

ON18

O N

ON24

O N31 O

N

ON19

ON22

ON21

ON33

ON30

ON28

ON27

ON16

Source: Esri, Maxar, Earthstar Geographics, and the GIS User Community

National Geographic, Esri, Garmin, HERE, UNEP-

WCMC, USGS, NASA, ESA,

FHWA CFLHD

New Mexico

Wild Rivers

Phase 2 Project Location

CV4

CV9

CV3

CV22

CV21

CV20

CV19

CV18

CV17

CV16

CV15

CV10

CV7/8

CV5/6

CV1/2

CV13/14

CV11/12

EXIST-PIP

ON4

ON1

ON11

ON18

ON2

ON5

ON6

ON20

ON14

O N

O N17

O N

O N

ON13

ON16

ON10

ON7

ON12

ON15

ON9

ON38

ON36

ON37

8575 8600

81008125

Source: Esri, Maxar, Earthstar Geographics, and the GIS User Community

1,000 0 1,000 2,000500

Feet

Legend

Multipatches !. Culvert BCBW Contour 25ft Contour 5ft DitchSubbasin

MATCHLINE SEE BELOW LEFT

MATCHLINE SEE ABOVE RIGHT

Appendix B. Culvert Inventory

Wild Rivers Back Country Byway - Phase 2 and 3 Appendix B

Culvert ID 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 Field Comments US Riprap US FES Pipe DS FES DS Riprap Recommended

Improvement US Riprap US FES Pipe DS FES DS Riprap

Recommended

Improvement

CV1 11+57 Pipe-Arch 35 24 CMP-16G 0.44 36.08 Poor Poor 6" to 12" 12" to 18" None Minor Full of branches D/S N N Y N Y Replace N Y Y Y Y Replace

CV2 15+92 Circular 18 CMP-16G 3.09 29.82 Poor Poor 12" to 18" 12" to 18" None None Buried D/S N N N N Y Clean N Y Y Y Y Clean

CV3 37+19 Pipe-Arch 21 15 CMP-16G 1.24 36.41 Poor Poor 1" to 2" 6" to 12" None None Full of branches U/S N N Y N Y Replace N Y Y Y Y Replace

CV4 37+26 Pipe-Arch 21 15 CMP-16G 1.57 36.23 Poor Poor 3" to 6" 6" to 12" None None Full of branches U/S N N Y N Y Replace N Y Y Y Y Replace

CV5 50+76 Pipe-Arch 21 15 CMP-16G 2.66 38.40 Fair Poor 1" to 2" 6" to 12" Minor Major Buried D/S Y N Y N Y Replace Y Y Y Y Y Replace

CV6 79+52 Pipe-Arch 21 15 CMP-16G 1.40 41.35 Poor Poor 6" 6" Minor Minor Full of branches D/S Y N Y N Y Replace Y Y Y Y Y Replace

CV7 98+45 Circular 36 CMP-16G 2.06 38.43 Good Good None None None None N N N N Y Extend N Y Y Y Y Replace

CV8 119+94 Pipe-Arch 35 24 CMP-16G 2.39 40.59 Fair Fair 1" to 2" 1" to 2" Minor Minor Full of branches U/S & D/S Y N N N Y Extend Y Y Y Y Y Replace

CV9 137+93 Pipe-Arch 21 15 CMP-16G 2.17 38.63 Fair Poor 1" to 2" 3" to 6" Minor Minor Full of branches U/S Y N N N Y Repalce Y Y Y Y Y Replace

CV10 144+44 Pipe-Arch 21 15 CMP-16G 2.11 36.53 Poor Poor 1" to 2" 3" to 6" None Minor Full of branches U/S N N Y N Y Replace N Y Y Y Y Replace

CV11 170+89 Circular 18 CMP-16G 1.44 40.96 Fair Fair 1" to 2" None Minor Minor Y N N N Y Extend Y Y Y Y Y Replace

CV12 184+63 Circular 36 CMP-16G 7.52 45.23 Fair Fair 1" to 2" 1" to 2" Minor Minor Full of branches U/S Y N N N Y Extend Y Y Y Y Y Replace

CV13 191+50 Circular 24 CMP-16G 4.96 44.97 Poor Fair 1" to 2" 1" to 2" Major Minor Full of branches U/S & D/S N N N N Y Extend N Y Y Y Y Replace

CV14 197+44 Circular 18 CMP-16G 7.80 40.50 Poor Fair 1" to 2" 2" to 4" None None Full of branches U/S N N N N Y Extend N Y Y Y Y Replace

CV15 201+36 Circular 24 CMP-16G 2.57 45.07 Fair Fair 1" to 2" 2" to 4" Minor None Full of branches U/S Y N Y N Y Replace Y Y Y Y Y Replace

CV16 212+30 Circular 24 CMP-16G 1.35 46.04 Poor Poor 18" to 24" 18" to 24" None None Mostly buried U/S & D/S N N N N Y Replace N Y Y Y Y Replace

CV17 220+17 Circular 24 CMP-16G 2.97 50.57 Fair Fair 1" to 2" 1" to 2" Minor Minor Full of branches U/S Y N N N Y Repalce Y Y Y Y Y Replace

CV18 220+25 Circular 24 CMP-16G 1.20 50.67 Fair Fair 1" to 2" 1" to 2" Minor Minor Full of branches U/S Y N N N Y Extend Y Y Y Y Y Replace

CV19 243+97 Pipe-Arch 21 15 CMP-16G 3.82 40.56 Good Fair None 1" to 2" None None N N N N Y Extend N Y Y Y Y Replace

CV20 253+14 Circular 48 CMP-16G 1.54 53.16 Good Good None 1" to 2" None None N N N N Y Extend N Y Y Y Y Replace

CV21 257+87 Circular 18 18 CMP-16G 4.54 40.29 Good Fair 1" to 2" 1" to 2" None None Full of branches D/S N N Y N Y Replace N Y Y Y Y Replace

CV22 308+50 Pipe-Arch 21 15 CMP-16G 2.27 38.84 Poor Poor 1" to 2" 1" to 2" Minor Minor Full of branches U/S & D/S Y N Y N Y Replace Y Y Y Y Y Replace

CV23 348+22 Pipe-Arch 21 15 CMP-16G 2.01 42.77 Poor Poor 3" to 6" 1" to 2" None Minor Full of branches U/S & D/S N N Y N Y Replace N Y Y Y Y Replace

CV24 363+94 Pipe-Arch 21 15 CMP-16G 1.44 50.70 Poor Poor 1" to 2" 1" to 2" None Minor N N Y N Y Replace N Y Y Y Y Replace

CV25 366+70 Pipe-Arch 21 15 CMP-16G 1.12 36.56 Poor Poor 1" to 2" 3" to 6" None None N N Y N Y Replace N Y Y Y Y Replace

CV26 388+82 Pipe-Arch 21 15 CMP-16G 2.02 38.54 Poor Fair 1" to 2" None Minor None Y N Y N Y Replace Y Y Y Y Y Replace

CV27 404+32 Circular 18 CMP-16G 1.95 40.50 Fair Fair 1" to 2" None None None N N N N Y Extend N Y Y Y Y Replace

CV28 412+88 Circular 24 CMP-16G 1.60 44.47 Good Fair None 1" to 2" None Minor Full of branches D/S N N N N Y Extend N Y Y Y Y Replace

Existing Survey Condition Assessment Field Verification 4/5/23 - Need for Replacement (Y/N)Existing Culvert Inventory Initial Field Verification - Need for Replacement (Y/N)

Appendix C. Hydrologic Analysis

C.1 Weighted Runoff Coefficient Calculations

C.2 Offsite Ditch Hydrologic Analysis

C.3 Onsite Ditch Hydrologic Analysis

NMWR PHASE 2 AND 3

FINAL DESIGN REPORT

HYDROLOGIC SUMMARY

Subbasin ID Runoff

Coefficient

Rainfall

Intensity

Tributary

Area

Peak

Flowrate

Runoff

Coefficient

Rainfall

Intensity

Tributary

Area

Peak

Flowrate

(C) (I, in/hr) (A, acres) (Q10, cfs) (C) (I, in/hr) (A, acres) (Q10, cfs)

ON1 0.24 1.46 102.56 36.1 16R 0.32 4.48 0.17 0.2

ON2 0.24 1.3 57.81 18.2 28R 0.58 4.48 0.69 1.8

ON3 0.22 1.39 9.66 3 49R 0.64 4.48 0.90 2.6

ON4 0.23 0.9 165.22 34.4 79R 0.58 4.48 2.58 6.8

ON5 0.21 0.89 34.32 6.5 96R 0.45 4.48 2.84 5.8

ON6 0.21 0.91 32.34 6.2 100R 0.58 4.48 0.69 1.8

ON7 0.24 1.16 3.82 1.1 118R 0.58 4.48 0.50 1.3

ON8 0.26 0.94 7.01 1.7 122R 0.58 4.48 0.09 0.2

ON9 0.24 1.52 1.52 0.6 126R 0.58 4.48 1.02 2.7

ON10 0.28 1.29 4.9 1.8 138R 0.51 4.48 0.17 0.4

ON11 0.25 0.86 84.43 18.3 165L 0.32 3.62 3.37 3.8

ON12 0.25 1.46 3.37 1.2 167R 0.71 4.48 0.43 1.4

ON13 0.23 1.44 8.48 2.8 174R 0.58 4.48 0.39 1.0

ON14 0.25 1.89 12.61 6 190R 0.71 4.48 0.24 0.8

ON15 0.25 1.89 1.97 0.9 193R 0.51 4.48 0.25 0.6

ON16 0.21 1.29 8.13 2.2 201R 0.64 4.48 0.24 0.7

ON17 0.24 1.29 10.63 3.3 204R 0.25 4.48 0.09 0.1

ON18 0.24 1.01 74.76 18.2 213R 0.71 4.48 0.50 1.6

ON19 0.23 1.33 9.66 3 224R 0.71 4.48 0.36 1.2

ON20 0.2 0.92 26.29 4.9 253R 0.64 4.48 0.25 0.7

ON21 0.24 1.44 2.98 1 262R 0.70 4.48 1.29 4.1

ON22 0.28 0.97 8.36 2.3 275R 0.64 4.48 0.68 2.0

ON23 0.23 0.77 17.79 3.2 304R 0.58 4.48 1.81 4.7

ON24 0.23 1.25 7.05 2 307R 0.58 4.48 0.21 0.6

ON25 0.23 0.63 20.46 3 311R 0.64 4.48 0.77 2.2

ON26 0.21 0.92 33.35 6.5 324R 0.58 4.48 0.46 1.2

ON27 0.32 1.8 0.3 0.2 335R 0.58 4.48 0.64 1.7

ON28 0.29 1.58 0.5 0.2 340R 0.84 4.48 0.38 1.4

ON29 0.23 0.94 14.63 3.2 346R 0.58 4.48 0.47 1.2

ON30 0.3 1.22 0.51 0.2 355R 0.58 4.48 0.53 1.4

ON31 0.3 0.97 5.26 1.5 363R 0.41 4.48 0.33 0.6

ON32 0.24 0.86 10.78 2.2 368R 0.64 4.48 1.07 3.1

ON33 0.23 1.17 2.97 0.8 382R 0.25 4.48 0.26 0.3

ON34 0.23 1.18 5.26 1.4 389R 0.51 4.48 0.50 1.1

ON35 0.22 0.99 23.63 5.2 404R 0.58 4.48 0.67 1.8

ON36 0.25 1.88 0.95 0.5 411R 0.51 4.48 0.39 0.9

ON37 0.29 1.94 0.95 0.5 414R 0.51 4.48 0.34 0.8

ON38 0.25 1.96 1.2 0.6

Subbasin ID

Appendix C.1 Weighted Runoff Coefficient Calculations

NMWR PHASE 2

OFFSITE WEIGHTED RUNOFF COMPUTATIONS

BASIN LATITUDE LONGITUDE

BASIN_AREA

(FT^2)

BASIN AREA

(AC)

RUNOFF

CLASSIFICATION

RUNOFF

COEFFICIENT ( C )

SEGMENTED AREA

(SA FT^2)

C x SA WEIGHTED C

ON1 36.76216 -105.6429 4467695.37 FOREST 0.25 3256119.55 814029.89

ON1 36.76216 -105.6429 4467695.37 PRAIRIE 0.20 1160632.37 232126.47

ON1 36.76216 -105.6429 4467695.37 102.56 ASPHALT 0.90 50943.38 45849.04 0.24

ON2 36.75924 -105.6454 2518382.44 FOREST 0.25 1856390.84 464097.71

ON2 36.75924 -105.6454 2518382.44 PRAIRIE 0.20 644964.08 128992.82

ON2 36.75924 -105.6454 2518382.44 57.81 ASPHALT 0.90 17027.72 15324.95 0.24

ON3 36.75840 -105.6511 420971.64 PRAIRIE 0.20 411331.43 82266.29

ON3 36.75840 -105.6511 420971.64 9.66 ASPHALT 0.90 9640.21 8676.19 0.22

ON4 36.75308 -105.6470 7196997.26 FOREST 0.25 3907800.23 976950.06

ON4 36.75308 -105.6470 7196997.26 PRAIRIE 0.20 3271486.23 654297.25

ON4 36.75308 -105.6470 7196997.26 165.22 ASPHALT 0.90 17710.80 15939.72 0.23

ON5 36.75336 -105.6587 1495061.00 PRAIRIE 0.20 1472298.96 294459.79

ON5 36.75336 -105.6587 1495061.00 34.32 ASPHALT 0.90 22762.00 20485.80 0.21

ON6 36.74946 -105.6673 1408633.79 PRAIRIE 0.20 1390265.50 278053.10

ON6 36.74946 -105.6673 1408633.79 32.34 ASPHALT 0.90 18368.42 16531.58 0.21

ON7 36.75086 -105.6697 166495.69 PRAIRIE 0.20 157083.41 31416.68

ON7 36.75086 -105.6697 166495.69 3.82 ASPHALT 0.90 9412.22 8471.00 0.24

ON8 36.74807 -105.6735 305322.74 PRAIRIE 0.20 277489.77 55497.95

ON8 36.74807 -105.6735 305322.74 7.01 ASPHALT 0.90 27832.98 25049.68 0.26

ON9 36.74599 -105.6758 66026.23 PRAIRIE 0.20 62128.94 12425.79

ON9 36.74599 -105.6758 66026.23 1.52 ASPHALT 0.90 3897.30 3507.57 0.24

ON10 36.74339 -105.6778 213391.42 FOREST 0.25 57364.59 14341.15

ON10 36.74339 -105.6778 213391.42 PRAIRIE 0.20 137241.52 27448.30

ON10 36.74339 -105.6778 213391.42 4.90 ASPHALT 0.90 18785.36 16906.82 0.28

ON11 36.73830 -105.6755 3677833.08 FOREST 0.25 3270678.65 817669.66

ON11 36.73830 -105.6755 3677833.08 PRAIRIE 0.20 391479.37 78295.87

ON11 36.73830 -105.6755 3677833.08 84.43 ASPHALT 0.90 15677.60 14109.84 0.25

ON12 36.73732 -105.6806 146762.39 FOREST 0.25 1435.48 358.87

ON12 36.73732 -105.6806 146762.39 PRAIRIE 0.20 134814.23 26962.85

ON12 36.73732 -105.6806 146762.39 3.37 ASPHALT 0.90 10512.76 9461.48 0.25

ON13 36.73798 -105.6792 369188.24 FOREST 0.25 138790.14 34697.53

ON13 36.73798 -105.6792 369188.24 PRAIRIE 0.20 226113.99 45222.80

ON13 36.73798 -105.6792 369188.24 8.48 ASPHALT 0.90 4281.68 3853.51 0.23

ON14 36.73395 -105.6799 549185.54 FOREST 0.25 491051.46 122762.87

ON14 36.73395 -105.6799 549185.54 PRAIRIE 0.20 52790.42 10558.08

ON14 36.73395 -105.6799 549185.54 12.61 ASPHALT 0.90 5343.64 4809.28 0.25

ON15 36.73140 -105.6828 85896.84 FOREST 0.25 45812.23 11453.06

ON15 36.73140 -105.6828 85896.84 PRAIRIE 0.20 37331.54 7466.31

ON15 36.73140 -105.6828 85896.84 1.97 ASPHALT 0.90 2753.08 2477.77 0.25

ON16 36.72645 -105.6839 354197.80 PRAIRIE 0.20 349283.91 69856.78

ON16 36.72645 -105.6839 354197.80 8.13 ASPHALT 0.90 4913.86 4422.48 0.21

ON17 36.72975 -105.6837 462952.18 FOREST 0.25 175133.15 43783.29

ON17 36.72975 -105.6837 462952.18 PRAIRIE 0.20 271807.85 54361.57

ON17 36.72975 -105.6837 462952.18 10.63 ASPHALT 0.90 16011.22 14410.10 0.24

ON18 36.72602 -105.6793 3256380.75 FOREST 0.25 2243095.08 560773.77

ON18 36.72602 -105.6793 3256380.75 PRAIRIE 0.20 1010109.47 202021.89

ON18 36.72602 -105.6793 3256380.75 74.76 ASPHALT 0.90 3176.23 2858.61 0.24

ON19 36.72518 -105.6864 420859.27 PRAIRIE 0.20 403438.77 80687.75

ON19 36.72518 -105.6864 420859.27 9.66 ASPHALT 0.90 17420.65 15678.59 0.23

ON20 36.72333 -105.6850 1144997.02 PRAIRIE 0.20 1137203.39 227440.68

ON20 36.72333 -105.6850 1144997.02 26.29 ASPHALT 0.90 7793.45 7014.11 0.20

ON21 36.72017 -105.6873 129914.50 PRAIRIE 0.20 121982.83 24396.57

ON21 36.72017 -105.6873 129914.50 2.98 ASPHALT 0.90 7931.67 7138.51 0.24

ON22 36.71581 -105.6901 364246.29 FOREST 0.25 46850.59 11712.65

ON22 36.71581 -105.6901 364246.29 PRAIRIE 0.20 152204.61 30440.92

ON22 36.71581 -105.6901 364246.29 PRAIRIE 0.20 124969.32 24993.86

ON22 36.71581 -105.6901 364246.29 ASPHALT 0.90 40203.80 36183.42

ON22 36.71581 -105.6901 364246.29 PRAIRIE 0.20 18.06 3.61

ON22 36.71581 -105.6901 364246.29 8.36 ASPHALT 0.90 0.03 0.02 0.28

ON23 36.70918 -105.6910 775109.48 PRAIRIE 0.20 736476.67 147295.33

ON23 36.70918 -105.6910 775109.48 ASPHALT 0.90 38614.73 34753.26

ON23 36.70918 -105.6910 775109.48 PRAIRIE 0.20 18.06 3.61

ON23 36.70918 -105.6910 775109.48 17.79 ASPHALT 0.90 0.03 0.02 0.23

ON24 36.70357 -105.6937 307021.13 PRAIRIE 0.20 295776.45 59155.29

ON24 36.70357 -105.6937 307021.13 7.05 ASPHALT 0.90 11244.67 10120.20 0.23

ON25 36.69942 -105.6990 891279.10 PRAIRIE 0.20 854245.41 170849.08

ON25 36.69942 -105.6990 891279.10 ASPHALT 0.90 37032.39 33329.15

ON25 36.69942 -105.6990 891279.10 20.46 PRAIRIE 0.20 1.34 0.27 0.23

GIS OUTPUT AND WEIGHTED RUNOFF COEFFICIENT CALCULATIONS

1 OF 2 11/20/2023

OFFSITE WEIGHTED RUNOFF COMPUTATIONS

BASIN LATITUDE LONGITUDE

BASIN_AREA

(FT^2)

BASIN AREA

(AC)

RUNOFF

CLASSIFICATION

RUNOFF

COEFFICIENT ( C )

SEGMENTED AREA

(SA FT^2)

C x SA WEIGHTED C

GIS OUTPUT AND WEIGHTED RUNOFF COEFFICIENT CALCULATIONS

ON26 36.69474 -105.7005 1452842.56 FOREST 0.25 22467.42 5616.86

ON26 36.69474 -105.7005 1452842.56 PRAIRIE 0.20 1416578.88 283315.78

ON26 36.69474 -105.7005 1452842.56 ASPHALT 0.90 13793.70 12414.33

ON26 36.69474 -105.7005 1452842.56 33.35 FOREST 0.25 2.43 0.61 0.21

ON27 36.69250 -105.7019 13224.83 FOREST 0.25 10861.29 2715.32

ON27 36.69250 -105.7019 13224.83 PRAIRIE 0.20 825.24 165.05

ON27 36.69250 -105.7019 13224.83 0.30 ASPHALT 0.90 1538.31 1384.48 0.32

ON28 36.69225 -105.7018 21608.61 FOREST 0.25 20336.57 5084.14

ON28 36.69225 -105.7018 21608.61 ASPHALT 0.90 1269.61 1142.65

ON28 36.69225 -105.7018 21608.61 0.50 FOREST 0.25 2.43 0.61 0.29

ON29 36.69221 -105.7000 637327.46 FOREST 0.25 285098.96 71274.74

ON29 36.69221 -105.7000 637327.46 PRAIRIE 0.20 341390.13 68278.03

ON29 36.69221 -105.7000 637327.46 ASPHALT 0.90 10828.35 9745.51

ON29 36.69221 -105.7000 637327.46 FOREST 0.25 6.04 1.51

ON29 36.69221 -105.7000 637327.46 14.63 PRAIRIE 0.20 4.14 0.83 0.23

ON30 36.69633 -105.7017 22236.14 PRAIRIE 0.20 19143.85 3828.77

ON30 36.69633 -105.7017 22236.14 ASPHALT 0.90 3091.01 2781.91

ON30 36.69633 -105.7017 22236.14 0.51 PRAIRIE 0.20 1.34 0.27 0.30

ON31 36.69024 -105.6986 229336.08 FOREST 0.25 209030.20 52257.55

ON31 36.69024 -105.6986 229336.08 PRAIRIE 0.20 3587.93 717.59

ON31 36.69024 -105.6986 229336.08 ASPHALT 0.90 16707.40 15036.66

ON31 36.69024 -105.6986 229336.08 FOREST 0.25 6.04 1.51

ON31 36.69024 -105.6986 229336.08 5.26 PRAIRIE 0.20 4.14 0.83 0.30

ON32 36.69067 -105.6939 469794.29 FOREST 0.25 73190.72 18297.68

ON32 36.69067 -105.6939 469794.29 PRAIRIE 0.20 378139.81 75627.96

ON32 36.69067 -105.6939 469794.29 10.78 ASPHALT 0.90 18463.72 16617.35 0.24

ON33 36.69019 -105.6922 129172.97 PRAIRIE 0.20 123833.57 24766.71

ON33 36.69019 -105.6922 129172.97 2.97 ASPHALT 0.90 5339.41 4805.46 0.23

ON34 36.68989 -105.6896 228999.30 PRAIRIE 0.20 218643.27 43728.65

ON34 36.68989 -105.6896 228999.30 5.26 ASPHALT 0.90 10356.00 9320.40 0.23

ON35 36.68972 -105.6857 1029461.20 PRAIRIE 0.20 1006462.31 201292.46

ON35 36.68972 -105.6857 1029461.20 23.63 ASPHALT 0.90 22998.89 20699.00 0.22

ON36 36.73173 -105.6826 41574.56 FOREST 0.25 20702.20 5175.55

ON36 36.73173 -105.6826 41574.56 PRAIRIE 0.20 19297.57 3859.51

ON36 36.73173 -105.6826 41574.56 0.95 ASPHALT 0.90 1574.79 1417.31 0.25

ON37 36.73305 -105.6823 41483.60 FOREST 0.25 1380.88 345.22

ON37 36.73305 -105.6823 41483.60 PRAIRIE 0.20 34921.49 6984.30

ON37 36.73305 -105.6823 41483.60 0.95 ASPHALT 0.90 5181.31 4663.18 0.29

ON38 36.73243 -105.6824 52313.91 FOREST 0.25 17945.67 4486.42

ON38 36.73243 -105.6824 52313.91 PRAIRIE 0.20 31728.10 6345.62

ON38 36.73243 -105.6824 52313.91 1.20 ASPHALT 0.90 2640.28 2376.25 0.25

2 OF 2 11/20/2023

ONSITE DITCH WEIGHTED RUNOFF CALCULATION

ID

Total Area

(SF)

Total Area

Embankment (SF)

Total Area

Asphalt (SF)

Total Area Rock

(SF)

Embankment

C=0.25

Asphalt

C=0.90

Rock

C=0.75 Aggregate C

16R 7209 6488 721 0 0.25 0.9 0.75 0.32

28R 30092 15046 15046 0 0.25 0.9 0.75 0.58

49R 39192 15677 23515 0 0.25 0.9 0.75 0.64

79R 112434 56217 56217 0 0.25 0.9 0.75 0.58

96R 123563 86494 37069 0 0.25 0.9 0.75 0.45

100R 30268 15134 15134 0 0.25 0.9 0.75 0.58

118R 21953 10977 10977 0 0.25 0.9 0.75 0.58

122R 3809 1905 1905 0 0.25 0.9 0.75 0.58

126R 44489 22245 22245 0 0.25 0.9 0.75 0.58

138R 7447 4468 2979 0 0.25 0.9 0.75 0.51

165L 146591 131932 14659 0 0.25 0.9 0.75 0.32

167R 18534 5560 12974 0 0.25 0.9 0.75 0.71

174R 17057 8529 8529 0 0.25 0.9 0.75 0.58

190R 10595 3179 7417 0 0.25 0.9 0.75 0.71

193R 10854 6512 4342 0 0.25 0.9 0.75 0.51

201R 10360 4144 6216 0 0.25 0.9 0.75 0.64

204R 4010 4010 0 0 0.25 0.9 0.75 0.25

213R 21916 6575 15341 0 0.25 0.9 0.75 0.71

224R 15886 4766 11120 0 0.25 0.9 0.75 0.71

253R 10906 4362 6544 0 0.25 0.9 0.75 0.64

261R 56394 5639 0 50755 0.25 0.9 0.75 0.70

275R 29678 11871 17807 0 0.25 0.9 0.75 0.64

304R 78671 39336 39336 0 0.25 0.9 0.75 0.58

307R 9208 4604 4604 0 0.25 0.9 0.75 0.58

312R 33725 13490 20235 0 0.25 0.9 0.75 0.64

324R 20122 10061 10061 0 0.25 0.9 0.75 0.58

335R 27672 13836 13836 0 0.25 0.9 0.75 0.58

340R 16523 1652 14871 0 0.25 0.9 0.75 0.84

346R 20281 10141 10141 0 0.25 0.9 0.75 0.58

355R 22875 11438 11438 0 0.25 0.9 0.75 0.58

363R 14377 10783 3594 0 0.25 0.9 0.75 0.41

368R 46542 18617 27925 0 0.25 0.9 0.75 0.64

382R 11195 11195 0 0 0.25 0.9 0.75 0.25

389R 21672 13003 8669 0 0.25 0.9 0.75 0.51

404R 29390 14695 14695 0 0.25 0.9 0.75 0.58

411R 17108 10265 6843 0 0.25 0.9 0.75 0.51

414R 14741 8845 5896 0 0.25 0.9 0.75 0.51

Runoff Coefficients CBasin Areas by land cover (SF)

Appendix C.2 Offsite Ditch Hydrologic Analysis

ON1

Hydraulic Analysis Report

Project Data Project Title: NMWR - Phase II, Basin ON1

Designer:

Project Date: Monday, December 5, 2022

Project Units: U.S. Customary Units

Notes:

Rational Analysis: ON1 - Runoff Calcs Notes:

Rational Method Input Parameters

Runoff Coefficient: 0.24

Basin Area: 102.5600 acres

Rainfall Intensity: 1.46 in/hr

Time of Concentration: 45.10 minutes

Recurrence Year: 10 year

IDF Input Parameters

User Supplied Data

2 year Recurrence, 5 min duration: 2.736 in/hr

2 year Recurrence, 10 min duration: 2.088 in/hr

2 year Recurrence, 15 min duration: 1.724 in/hr

2 year Recurrence, 30 min duration: 1.162 in/hr

2 year Recurrence, 60 min duration: 0.719 in/hr

5 year Recurrence, 5 min duration: 3.732 in/hr

5 year Recurrence, 10 min duration: 2.838 in/hr

5 year Recurrence, 15 min duration: 2.348 in/hr

Appendix C

5 year Recurrence, 30 min duration: 1.58 in/hr

5 year Recurrence, 60 min duration: 0.978 in/hr

10 year Recurrence, 5 min duration: 4.536 in/hr

10 year Recurrence, 10 min duration: 3.45 in/hr

10 year Recurrence, 15 min duration: 2.852 in/hr

10 year Recurrence, 30 min duration: 1.922 in/hr

10 year Recurrence, 60 min duration: 1.189 in/hr

25 year Recurrence, 5 min duration: 5.7 in/hr

25 year Recurrence, 10 min duration: 4.338 in/hr

25 year Recurrence, 15 min duration: 3.588 in/hr

25 year Recurrence, 30 min duration: 2.414 in/hr

25 year Recurrence, 60 min duration: 1.494 in/hr

50 year Recurrence, 5 min duration: 6.672 in/hr

50 year Recurrence, 10 min duration: 5.076 in/hr

50 year Recurrence, 15 min duration: 4.196 in/hr

50 year Recurrence, 30 min duration: 2.824 in/hr

50 year Recurrence, 60 min duration: 1.748 in/hr

100 year Recurrence, 5 min duration: 7.74 in/hr

100 year Recurrence, 10 min duration: 5.892 in/hr

100 year Recurrence, 15 min duration: 4.868 in/hr

100 year Recurrence, 30 min duration: 3.278 in/hr

100 year Recurrence, 60 min duration: 2.028 in/hr

IDF Results

10 year IDF equation: i = 34.61 / (Tc + 7.788)^0.7985

Intensity: 1.4562 in/hr

Time of Concentration Input Parameters

Computed Time of Concentration

Time of Concentration: 45.10 min

Sheet Flow Input Parameters

Top Elevation: 8050.00 ft

Bottom Elevation: 8035.00 ft

Length: 100.00 ft

Recommended length not to exceed 100'. Maximum length is 300'

Manning's n: 0.4000

See HDS-2 Table 2.1

2 yr, 24 hr precip: 1.2100 in

Sheet Flow Results

Slope: 0.1500 ft/ft

Time of Concentration: 15.60 min

Shallow Concentrated Flow Input Parameters

Top Elevation: 8035.00 ft

Bottom Elevation: 7503.00 ft

Length: 3474.00 ft k: 0.1520

See HDS-2 Table 2.2

Shallow Concentrated Flow Results

Slope: 0.1531 ft/ft

Velocity: 1.9629 ft/s

HDS-2 equation 2.7

Time of Concentration: 29.50 min

Total Time of Concentration 3

Time of Concentration: 45.10 min

Rational Method Results

Flowrate: 36.1 cfs

ON2

Project Title: NMWR - Phase II, Basin ON2

Designer:

Project Date: Monday, December 5, 2022

Project Units: U.S. Customary Units

Notes:

Rational Analysis: ON2 - Runoff Calcs Notes:

Rational Method Input Parameters

Runoff Coefficient: 0.24

Basin Area: 57.8100 acres

Rainfall Intensity: 1.30 in/hr

Time of Concentration: 53.15 minutes

Recurrence Year: 25 year

IDF Input Parameters

User Supplied Data

2 year Recurrence, 5 min duration: 2.736 in/hr

2 year Recurrence, 10 min duration: 2.088 in/hr

2 year Recurrence, 15 min duration: 1.724 in/hr

2 year Recurrence, 30 min duration: 1.162 in/hr

2 year Recurrence, 60 min duration: 0.719 in/hr

5 year Recurrence, 5 min duration: 3.732 in/hr

5 year Recurrence, 10 min duration: 2.838 in/hr

5 year Recurrence, 15 min duration: 2.348 in/hr

5 year Recurrence, 60 min duration: 0.978 in/hr

10 year Recurrence, 5 min duration: 4.536 in/hr

10 year Recurrence, 10 min duration: 3.45 in/hr

10 year Recurrence, 15 min duration: 2.852 in/hr

10 year Recurrence, 30 min duration: 1.922 in/hr

10 year Recurrence, 60 min duration: 1.189 in/hr

25 year Recurrence, 5 min duration: 5.7 in/hr

25 year Recurrence, 10 min duration: 4.338 in/hr

25 year Recurrence, 15 min duration: 3.588 in/hr

25 year Recurrence, 30 min duration: 2.414 in/hr

25 year Recurrence, 60 min duration: 1.494 in/hr

50 year Recurrence, 5 min duration: 6.672 in/hr

50 year Recurrence, 10 min duration: 5.076 in/hr

50 year Recurrence, 15 min duration: 4.196 in/hr

50 year Recurrence, 30 min duration: 2.824 in/hr

50 year Recurrence, 60 min duration: 1.748 in/hr

100 year Recurrence, 5 min duration: 7.74 in/hr

100 year Recurrence, 10 min duration: 5.892 in/hr

100 year Recurrence, 15 min duration: 4.868 in/hr

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