NM_FLAP_SIE10(1)_Lakeshore_Final_Hydraulics_Report_wApp.pdf

Lakeshore Road NM State Parks Division

US Bureau of Reclamation Sierra County, NM

NM FLAP SIE 10(1)

Final Hydraulics Report

Federal Highway Administration

Central Federal Lands Highway Division

26 May 2022

Page 1 NM FLAP SIE10(1) Lakeshore Road – Final Hydraulics Report

Executive Summary

Hydrologic and hydraulic analyses were conducted for the NM FLAP SIE 10(1) Lakeshore road Project. For the hydraulics report the 50-year flood and 100-year floods were selected as the hydraulic design flood and the check flood, respectively. The peak flow values were estimated using USGS regression equations for New Mexico. Existing and proposed conditions two-dimensional hydraulic modeling using SRH-2D was conducted to estimate water surface elevations, depths, and flow velocities at the project site. Scour depth estimates were conducted in accordance with HEC-18 using a 100-year scour design flood and 200-year scour check flood. The tables below show the structure recommendations for Sites 1 to 4 based on the results of the hydraulic analyses. Based on direction from the project partners, Site 5 was eliminated from the project but the hydraulics analyses are included in this report for reference.

Culvert Recommendations (Site 1 and 2)

Site Proposed Culvert (span x height)

Upstream Invert (ft)

Downstream Invert (ft)

Length

(ft) Remarks

Site 1 (2) 10' x 5' CBC 4449.4 4435.0 122 Energy dissipation provided by 28’ SAF stilling basin. Class 3 riprap apron downstream.

Site 2 (2) 10' x 5' CBC 4454.4 4449.1 123 Energy dissipation provided by a 26’ SAF stilling basin. Class 2 riprap apron downstream.

Bridge Recommendations (Site 3 and 4)

Site Proposed Structure Low Chord Elevation (ft) Remarks

Site 3 70’ Bridge Length 4486.5 Class 3 riprap abutment protection.

Minimum 6-foot apron from toe of abutment.

Site 4 110' Bridge Length 4462.4

Class 3 riprap abutment protection.

Minimum 6-foot apron from toe of abutment. Class 3 roadway embankment protection.

Page 2 NM FLAP SIE10(1) Lakeshore Road – Final Hydraulics Report

Table of Contents

1 Project Background Information

2 Hydraulic Design Criteria

3 Hydrology

3.1 Hydrologic Setting

3.2 FEMA Flood Insurance Study

3.3 Available Hydrologic Data

3.4 Regression Equation Estimates

3.5 Rainfall-Runoff Model Estimates

3.5.1 Precipitation

3.5.2 Basin Parameters

3.6 Recommended Design Discharges

4 Hydraulic Analysis

4.1 Topographic Information

4.2 Existing Culverts

4.3 Hydraulic Model Development

4.4 Hydraulic Model Results

4.4.1 Existing Conditions

4.4.2 Site 1 Proposed Conditions

4.4.3 Site 2 Proposed Conditions

4.4.4 Site 3 Proposed Conditions

4.4.5 Site 4 Proposed Conditions

4.5 Bridge Scour Assessment

4.5.1 Geotechnical Investigation

4.5.2 Site 3 Scour Estimates

4.5.3 Site 4 Scour Estimates

4.6 Site 5 Low Water Crossing

5 Summary of Recommendations

6 References

Page 3 NM FLAP SIE10(1) Lakeshore Road – Final Hydraulics Report

Tables Table 1: Hydraulic Design Criteria Table 2: Basin Properties Table 3: Available Peak Streamflow Information Table 4: StreamStats Peak Discharge Estimates at Project Sites Table 5: NOAA Atlas 14 24-Hour Point Precipitation – Truth or Consequences, NM Table 6: Basin Parameters (NRCS Method) Table 7: HEC-HMS Peak Discharge Estimates at Project Site Table 8: Recommended Design Flows Table 9: Existing Culvert Properties Table 10: Project Land Cover Types and Manning’s Roughness Table 11: 50-year and 100-year Existing Conditions Hydraulic Results Table 12: Site 1 50-year and 100-year Proposed Conditions Hydraulic Results Table 13: Site 2 50-year and 100-year Proposed Conditions Hydraulic Results Table 14: Site 3 50-year and 100-year Proposed Conditions Hydraulic Results Table 15: Site 3 50-year and 100-year Proposed Conditions Hydraulic Results Table 16: Site 3 Contraction Scour Estimates Table 17: Site 3 Abutment Scour Estimates Table 18: Site 3 Total Scour Results Table 19: Site 4 Contraction Scour Estimates Table 20: Site 4 Abutment Scour Estimates Table 21: Site 4 Total Scour Results Table 22: Proposed Culverts for Site 1 and 2 Table 23: Proposed Bridges for Site 3 and 4

Figures Figure 1: Project location map Figure 2: Drainage Basin Map Figure 3: Site 1 Topographic Surface, Elevations in feet referenced to NAVD88 Figure 4: Site 2 Topographic Surface, Elevations in feet referenced to NAVD88 Figure 5: Site 3 Topographic Surface, Elevations in feet referenced to NAVD88 Figure 6: Site 4 Topographic Surface, Elevations in feet referenced to NAVD88 Figure 7: SAF Stilling Basin Figure 8: Site 1 50-Year Water Surface Profile (Proposed vs Existing) Figure 9: Site 1 50-Year Water Surface Elevation (Proposed vs Existing) Figure 10: Site 2 50-Year Water Surface Profile (Proposed vs Existing) Figure 11: Site 2 50-Year Water Surface Elevation (Proposed vs Existing) Figure 12: Site 3 50-Year Water Surface Profile (Proposed vs Existing) Figure 13: Site 3 50-Year Water Surface Elevation (Proposed vs Existing) Figure 14: Site 4 50-Year Water Surface Profile (Proposed vs Existing)

Page 4 NM FLAP SIE10(1) Lakeshore Road – Final Hydraulics Report

Figure 15: Site 4 50-Year Water Surface Elevation (Proposed vs Existing) Figure 16: Site 5 2-Year Water Surface Extents

Appendices Appendix A: Hydrologic Analyses Appendix B: Hydraulic analyses

Page 5 NM FLAP SIE10(1) Lakeshore Road – Final Hydraulics Report

1 PROJECT BACKGROUND INFORMATION

The Lakeshore Road project is located in Sierra County, NM within the Elephant Butte Lake State Park which is managed by NM State Parks under a lease agreement with the U.S. Bureau of Reclamation.

Hydraulic improvements are proposed at five sites identified during the project development phase, see Figure 1. Sites 1 to 4 consist of existing culvert crossings on Lakeshore Road, and Site 5 is an existing low water crossing on Three Sisters Road. The existing culverts do not have adequate capacity to convey the basin peak flows, and the capacity is further limited by the volume of sediment being transported in the system. Sediment aggradation, streambed degradation, and roadway overtopping are the principal hydraulic problems identified at the sites. The project proposes to increase conveyance capacity to transport floods and sediment adequately through the drainage system.

Figure 1: Project location map.

Page 6 NM FLAP SIE10(1) Lakeshore Road – Final Hydraulics Report

2 HYDRAULIC DESIGN CRITERIA

The Federal Lands Highway Project Development and Design Manual (PDDM) (Federal Lands Highway 2012) establishes the hydraulic design criteria. Based on the project scoping report the road has a design speed of 40 mph and a design seasonal average daily traffic (SADT) of 1708 vehicles. Based on these parameters the road is classified as high standard for hydraulic design purposes. The applicable design criteria are listed in Table 1.

Table 1: Hydraulic Design Criteria

Road Classification: High-Standard Road (Design ADT 1708 vpd)

Bridges

Design Frequency Check Frequency Freeboard

50-year flood

Greater of 100-year or overtopping flood

• Minimum of 2 feet

• 3.5 feet to 5 feet when woody debris potential is significant

• 5 feet to 10 feet when ice flow potential is significant

Scour

Scour Design

Frequency Scour Check Frequency Scour Countermeasure Design Frequency

100-year flood 200-year flood 200-year flood

Floodplain Encroachment

FEMA SFHA Involvement Allowable Rise Project within FEMA regulated special flood hazard area (SFHA) – Zone A Maximum 1-foot rise in water surface profile over existing conditions

Culverts:

Design Frequency Check Frequency Allowable Headwater

50-year flood

100-year or Overtopping flood

Minimum of:

• Bottom of aggregate base layer

• HW/D ratio of 1.2 for D > 48", 1.5 for D ≤ 48”

• Heavy debris or sediment load concerns:

0.8 ≤ HW/D ≤ 1.0

• Unacceptable hazard to human life or property

Low Water Crossings

Design Frequency Stability Extent of Protection

N/A since all flow must pass 25-year Flood • 2-year flood

Page 7 NM FLAP SIE10(1) Lakeshore Road – Final Hydraulics Report

3 HYDROLOGY

3.1 HYDROLOGIC SETTING

The project is located within the Ash Canyon-Elephant Butte Reservoir Subwatershed (HUC12:

13020211080) and the Cedar Canyon-Elephant Butte Reservoir Subwatershed (HUC12: 130202110804), which belong to the Elephant Butte Reservoir Subbasin (HUC8: 13020211). The total drainage area to the dam is approximately 28,900 square miles. The five project sites convey flow from ephemeral drainages across existing roads. The general flow direction is from west to east to their respective outfalls at Elephant Butte Reservoir. The majority of rainfall in the region occurs from June to October where convective storms of high intensity dominate. The contributing drainage basins to the sites were delineated using available 10-meter digital elevation model (DEM) information obtained from the USGS National Map as shown in Figure 2. A summary of general basin properties is shown in Table 2. Site 2 has two distinct channel threads that join at the culvert crossing therefore the basin properties are shown for the north and south thread separately.

Table 2: Basin Properties

Site Drainage Area (mi2)

Mean Basin Elevation (ft)

Mean Basin Slope (%)

Mean Annual Precipitation (in)

Site 1 1.1 4,630 7.3 10.2 Site 2 N 0.6 4,570 1.0 10.1 Site 2 S 0.4 4,580 7.1 10.1 Site 3 2.7 4,730 5.0 10.2 Site 4 12.6 4,870 3.0 10.6 Site 5 1.6 4,670 5.7 10.1

Page 8 NM FLAP SIE10(1) Lakeshore Road – Final Hydraulics Report

Figure 2: Drainage Basin Map

3.2 FEMA FLOOD INSURANCE STUDY

According to FEMA Flood Insurance Study of Sierra County Unincorporated Areas, effective July 1996 and Flood Insurance Rate Map (FIRM) panels 3500710300B and 3500710485C, the project is located within the FEMA Zone A special flood hazard area (SFHA). The SFHA comprises the land area that is shown in the FIRM as being inundated by the 1% chance (100-year) base flood and where the National Flood Insurance Program's (NFIP) floodplain management regulations apply. The boundaries of FEMA Zone A are determined using approximate methods therefore no base flood elevations (BFEs) are shown in the FIRM.

The PDDM criteria for Zone A allows a maximum of 1-foot rise in proposed conditions base flood elevations when compared to the existing condition.

3.3 AVAILABLE HYDROLOGIC DATA

There are no active USGS peak streamflow stations within the project limits. The closest USGS active station is located in the Rio Grande River approximately 10 miles north of the project. Although listed as an active station the period of record for peak streamflow data is limited. Due to the size of the project

Page 9 NM FLAP SIE10(1) Lakeshore Road – Final Hydraulics Report drainage basin compared to the Rio Grande River basin the streamflow information was not used in the hydrology analysis for the project. Table 3 summarizes the station location and period of record.

Table 3: Available Peak Streamflow Information

USGS

Station Location Latitude Longitude Drainage

Area

Period of

Record

Total Peak Streamflow

Records Status

08359500 Rio Grande River at Narrows in Elephant

Butte Res. NM 33°23'10" 107°09'45" 28,500 mi2 1951-

2020 6 Active

3.4 REGRESSION EQUATION ESTIMATES

The StreamStats web application (U.S. Geological Survey 2016) was used to estimate peak flows for the project sites. The New Mexico StreamStats application uses the regression equations presented in USGS Report 2008-5119 (Waltenmeyer 2008). According to the report the project is located in the southwest desert flood region (Region 7). The region 7 equations relate peak discharge to drainage area. According to the study the average standard errors of prediction for the equations vary from 37 to 63 percent. The results for the project basins are shown in Table 4.

Table 4: StreamStats Peak Discharge Estimates at Project Sites

Percent Chance Exceedance (%) Return Period (year)

Peak Flow (cfs) Site 1 Site 2 N Site 2 S Site 3 Site 4 Site 5

50 2 154 101 60 231 463 181 20 5 292 189 111 444 909 345 10 10 408 262 152 625 1,300 484 4 25 583 371 212 902 1,910 694 2 50 733 462 262 1,140 2,450 876 1 100 898 562 315 1,410 3,070 1,080

0.5 200 1,135 703 390 1,796 3,973 1,366

0.2 500 1,350 826 451 2,160 4,870 1,630

3.5 RAINFALL-RUNOFF MODEL ESTIMATES

3.5.1 Precipitation

The point precipitation values for the project were obtained from NOAA Atlas 14 Volume 1 (Perica, Dietz, et al. 2011) using the Precipitation Frequency Data Server (National Oceanic and Atmospheric Administration 2011).

The point precipitation values were obtained at the Truth or Consequences station (ID 29-9129) and are assumed to represent precipitation over the entire project area. NOAA Atlas 14 states that point

Page 10 NM FLAP SIE10(1) Lakeshore Road – Final Hydraulics Report precipitation values within the project area are equal to point rainfall values. The point precipitation/rainfall values for a duration of 24 hours and various return periods are shown in Table 5.

Table 5: NOAA Atlas 14 24-Hour Point Precipitation – Truth or Consequences, NM

Percent Chance Exceedance (%)

Return Period (year)

Point Precipitation (inches)

50 2 1.48 20 5 1.85 10 10 2.16 4 25 2.62 2 50 3.00 1 100 3.42

0.5 200 3.90

0.2 500 4.61

3.5.2 Basin Parameters

The NRCS curve number (CN) method (Natural Resources Conservation Service 1997) was used to estimate runoff. A composite CN for the basin was estimated using SSURGO soil information (Natural Resources Conservation Service 2015) and the 2011 national land cover dataset (Multi-Resolution Land Characteristics Consortium 2018). Soils within the Site and 2 basins are classified predominately as hydrologic soil groups (HSG) C and D, while soils within Sites 3 and 4 are comprised mostly of HSG A and C. Land cover for the project basins consists primarily of desert shrub/scrub areas, with some grassland/herbaceous areas interspersed throughout. Time of concentration was estimated by various methods, the Kirpich method resulted in the lowest times and was selected for the analyses. The NRCS and unit hydrograph was used to estimate peak flows from the basins. A frequency storm based on the NOAA Atlas 14 precipitation data was used to develop the rainfall distribution according to guidance from the NMDOT drainage design manual (New Mexico Department of Transportation 2018). A summary of basin parameters is shown in Table 6.

Table 6: Basin Parameters (NRCS Method)

Basin Parameter Site 1 Site 2 N Site 2 S Site 3 Site 4 Site 5

Drainage Area (sq. mi.) 1.12 0.44 0.14 2.72 13.25 1.50 Composite Curve

Number (CN) 78.7 81.0 80.5 65.6 63.4 70.7

Lag Time (min) 43 18 12 73 125 51

The hydrologic computations were carried out using HEC-HMS (U.S. Army Corps of Engineers 2017). The results for various return periods are shown in Table 7.

Page 11 NM FLAP SIE10(1) Lakeshore Road – Final Hydraulics Report

Table 7: HEC-HMS Peak Discharge Estimates at Project Site

Percent Chance Exceedance (%) Return Period (year)

Peak Flow (cfs) Site 1 Site 2 N Site 2 S Site 3 Site 4 Site 5

50 2 54 50 18 4 13 11 20 5 128 112 41 25 48 51 10 10 204 172 64 68 149 102 4 25 326 266 100 159 384 197 2 50 435 347 132 254 641 289 1 100 560 438 169 376 978 400

0.5 200 700 538 209 525 1,400 530

0.2 500 908 680 267 766 2,096 732

3.6 RECOMMENDED DESIGN DISCHARGES

The recommended design flows for the project sites are shown in Table 8. The regression equation results were selected since there is no streamflow data available to calibrate/validate the rainfall-runoff values and the peak flow results are more conservative. Additional details of the hydrologic analysis are provided in Appendix A.

Table 8: Recommended Design Flows

Percent Chance Exceedance (%) Return Period (year)

Peak Flow (cfs) Site 1 Site 2 N Site 2 S Site 3 Site 4 Site 5

50 2 154 101 60 231 463 181 20 5 292 189 111 444 909 345 10 10 408 262 152 625 1,300 484 4 25 583 371 212 902 1,910 694 2 50 733 462 262 1,140 2,450 876 1 100 898 562 315 1,410 3,070 1,080

0.5 200 1,135 703 390 1,796 3,973 1,366

0.2 500 1,350 826 451 2,160 4,870 1,630

4 HYDRAULIC ANALYSIS

Hydraulic analyses were conducted for Sites 1 to 5. The objective of the analyses was to establish the hydraulic capacity requirements at each site using the available data and two-dimensional hydraulic modeling. The input data, model development, and results are discussed in the following sections. Site 5 is an existing low water crossing; the project proposes to improve the resiliency of this crossing.

Page 12 NM FLAP SIE10(1) Lakeshore Road – Final Hydraulics Report

4.1 TOPOGRAPHIC INFORMATION

Field survey information collected by Central Federal Lands was used to develop the hydraulic models for the sites. The survey information was processed to create triangular irregular network (TIN) surfaces to represent the topography in the streambed and floodplain areas near the existing crossings as shown in Figure 3 to Figure 6. All elevations for the study are in units of feet and are referenced to the North American Vertical Datum of 1988 (NAVD 88).

Figure 3: Site 1 Topographic Surface, Elevations in feet referenced to NAVD88

Site 1

Page 13 NM FLAP SIE10(1) Lakeshore Road – Final Hydraulics Report

Figure 4: Site 2 Topographic Surface, Elevations in feet referenced to NAVD88

Site 2

Page 14 NM FLAP SIE10(1) Lakeshore Road – Final Hydraulics Report

Figure 5: Site 3 Topographic Surface, Elevations in feet referenced to NAVD88

Site 3

Page 15 NM FLAP SIE10(1) Lakeshore Road – Final Hydraulics Report

Figure 6: Site 4 Topographic Surface, Elevations in feet referenced to NAVD88

4.2 EXISTING CULVERTS

The physical properties of the existing culverts were obtained from the field survey as shown in Table 9.

The approximate overtopping elevation is the low point in the roadway profile in the vicinity of the culvert where water begins to flow over the roadway embankment.

Table 9: Existing Culvert Properties

Site Existing Culvert Type

Upstream Invert (ft)

Downstream Invert

(ft) Length (ft)

Approximate Overtopping Elevation (ft)

Site 1 (2) 84" CMP 4448.8 4448.0 52 4457.3

Site 2 (3) 36" CMP 4454.4 4453.3 65 4458.8-4461.5 (superelevated)

Site 4

Page 16 NM FLAP SIE10(1) Lakeshore Road – Final Hydraulics Report

Site 3 (2) 48" CMP 4479.3 4477.3 120 4489.7

Site 4

North: (2) 24"

CMP 4460.8 4459.1 77 4463.3

South: (5) 36"

CMP 4457.0 4455.8 94 4463.3

4.3 HYDRAULIC MODEL DEVELOPMENT

Two-dimensional hydraulic simulations were conducted using SRH-2D (U.S. Bureau of Reclamation 2017) to estimate water surface elevations, water depth and flow velocities at the project sites. The model pre-and post-processing was performed using the SMS 13.0.11 interface (Aquaveo 2019). The model domain limits were selected to capture up to a 500-year event.

The upstream boundary conditions in the model were specified as a steady discharge using the peak flows in shown in Table 8. The downstream boundary conditions were specified as known water surface elevations obtained using Manning’s equation and a energy grade line slope assumed to equal the streambed slope near the model outlet. The existing culverts were modeled as one-dimensional elements using the HY-8 (Federal Highway Administration 2017) interface in SRH-2D.

SRH-2D uses Manning’s “n” values to calculate bed friction. The land use types were delineated from aerial imagery and assigned standard roughness values. The roughness values used in the model are shown in Table 10.

Table 10: Project Land Cover Types and Manning’s Roughness

Land Use Manning's "n" Main Channel 0.035

Floodplain Brush 0.050 Roadway 0.016

4.4 HYDRAULIC MODEL RESULTS

4.4.1 Existing Conditions

Existing conditions hydraulic simulations using the parameters described in Section 4.2 were conducted for the 2-, 5-, 10-, 25-, 50-, 100-, 200-, and 500-year return periods. A summary of existing conditions results were extracted at a section upstream of the existing culvert inlet. The results are summarized in Table 11 for the 50-year and 100-year return periods, respectively. Maps showing the two-dimensional water surface elevation and velocity results are included in Appendix B.

Table 11: 50-year and 100-year Existing Conditions Hydraulic Results

Site Return Period (year) Velocity (ft/s) Depth (ft) WSEL (ft)

Average Maximum Average Maximum Average Maximum

Site 1 50 0.3 1.5 3.4 8.2 4457.6 4457.6

100 0.3 1.6 3.5 8.4 4457.9 4457.9

Page 17 NM FLAP SIE10(1) Lakeshore Road – Final Hydraulics Report

Site 2 50 0.9 2.0 2.8 7.4 4461.7 4461.8

100 1.0 2.4 2.7 7.5 4461.9 4461.9

Site 3 50 0.3 1.5 4.7 9.7 4490.6 4490.6

100 0.4 1.7 4.8 9.9 4490.8 4490.9

Site 4 50 1.2 2.5 4.6 9.6 4465.7 4465.8

100 1.5 3.0 4.8 9.9 4466.0 4466.2

4.4.2 Site 1 Proposed Conditions

The proposed structure for Site 1 is a double barrel 10’ (span) x 5’ (height) concrete box culvert. Due to the channel degradation that has occurred downstream the culvert is steep having an approximate 12% slope. To provide energy dissipation the culvert will outlet into a 28’ long Saint Anthony Falls (SAF) stilling basin designed in accordance with HEC-14 (Federal Highway Administration 2006). The SAF basin, shown in Figure 7, provides energy dissipation by means of a stilling basin, chute blocks, and baffle blocks to create a hydraulic jump. Construction details are shown in the stilling basin sheets of the plans. Additional details of the hydraulic analysis are included in Appendix B.

Figure 7: SAF Stilling Basin

Page 18 NM FLAP SIE10(1) Lakeshore Road – Final Hydraulics Report

Figure 8 shows a comparison between proposed and existing water surface profiles in the vicinity of the culvert for the 50-year design frequency. Figure 9 compares the 50-year inundation limits between the existing and proposed conditions. The proposed culvert eliminates the roadway overtopping that was estimated for the 50-year existing conditions model.

Figure 8: Site 1 50-Year Water Surface Profile (Proposed vs Existing)

Figure 9: Site 1 50-Year Water Surface Elevation (Proposed vs Existing)

Overtopping

Proposed Existing

Existing Culvert Proposed Culvert

Page 19 NM FLAP SIE10(1) Lakeshore Road – Final Hydraulics Report

Pertinent 50-year and 100-year hydraulic results for the proposed culvert are shown in Table 12. The proposed culvert has a 50-year headwater to depth ratio (HW/D) of 1.0 which satisfies FLH design criteria.

The stilling basin exit velocity has been designed to match the tailwater channel velocity. A 10-foot long Class 3 riprap apron is recommended downstream of the stilling basin.

Table 12: Site 1 50-year and 100-year Proposed Conditions Hydraulic Results

Return Period (year)

Flow (cfs)

Culvert Outlet Velocity (ft/s)

Tailwater Velocity (ft/s)

Stilling Basin Exit Velocity (ft/s)

Headwater Elevation (ft) HW/D

50 733 30.1 10.7 10.7 4454.6 1.0 100 898 31.1 11.5 11.5 4455.6 1.2

4.4.3 Site 2 Proposed Conditions

The proposed structure for Site 2 is double barrel 10’ (span) x 5’ (height) concrete box culvert with an approximate 4% slope. To provide energy dissipation the culvert will outlet into a 26’ long Saint Anthony Falls (SAF) stilling basin (Federal Highway Administration 2006). The SAF provides energy dissipation by means of a stilling basin, chute blocks, and baffle blocks to create a hydraulic jump. Construction details are shown in the stilling basin sheets of the plans.

Figure 10 shows a comparison between proposed and existing water surface profiles in the vicinity of the culvert for the 50-year design frequency. Figure 11 compares the 50-year inundation limits between the existing and proposed conditions. The proposed culvert eliminates the roadway overtopping that was estimated for the 50-year existing conditions model.

Figure 10: Site 2 50-Year Water Surface Profile (Proposed vs Existing)

Proposed Existing

Page 20 NM FLAP SIE10(1) Lakeshore Road – Final Hydraulics Report

Figure 11: Site 2 50-Year Water Surface Elevation (Proposed vs Existing)

Pertinent 50-year and 100-year hydraulic results for the proposed culvert shown in Table 13. The proposed culvert has a 50-year headwater to depth ratio (HW/D) of 1.1 which satisfies FLH design criteria.

The stilling basin exit velocity has been designed to match the tailwater channel velocity. A 10-foot long Class 2 riprap apron is recommended downstream of the stilling basin.

Table 13: Site 2 50-year and 100-year Proposed Conditions Hydraulic Results

Return Period (year)

Flow (cfs)

Culvert Outlet Velocity (ft/s)

Tailwater Velocity (ft/s)

Stilling Basin Exit Velocity (ft/s)

Headwater Elevation (ft) HW/D

50 724 21.35 7.9 7.9 4459.7 1.1 100 877 22.13 8.5 8.5 4460.7 1.3

Existing Culvert Proposed Culvert

Page 21 NM FLAP SIE10(1) Lakeshore Road – Final Hydraulics Report

4.4.4 Site 3 Proposed Conditions

The proposed structure for Site 3 is a 70’ long bridge with an approximate low chord elevation of 4486.5’.

The proposed bridge has vertical abutments and an approximate 65’ waterway width. The existing roadway will be realigned to the west to meet superelevation and other geometric criteria. The existing roadway embankment will be removed downstream of the proposed bridge and a channel created to convey flows through and downstream of the bridge opening Figure 12 shows a comparison between proposed and existing water surface profiles in the vicinity of the bridge for the 50-year design frequency.

Figure 13 compares the 50-year inundation limits between the existing and proposed conditions. The proposed culvert eliminates the roadway overtopping that was estimated for the 50-year existing conditions model. Additional details of the hydraulic analysis are included in Appendix B.

Figure 12: Site 3 50-Year Water Surface Profile (Proposed vs Existing)

Existing

Proposed Bridge

Existing roadway to be removed

Page 22 NM FLAP SIE10(1) Lakeshore Road – Final Hydraulics Report

Figure 13: Site 3 50-Year Water Surface Elevation (Proposed vs Existing)

Pertinent 50-year and 100-year hydraulic results for the proposed bridge are shown in Table 14. The table shows average and maximum hydraulic results at the upstream face of the proposed bridge and at a distance approximately one bridge width upstream.

Table 14: Site 3 50-year and 100-year Proposed Conditions Hydraulic Results

Location Return Period (year) Velocity (ft/s) Depth (ft) WSEL (ft)

Average Maximum Average Maximum Average Maximum

Upstream Bridge Face

50 10.2 12.3 2.3 2.9 4483.0 4483.3 100 10.5 12.7 2.6 3.3 4483.4 4483.7

Approximately 35’ Upstream of Bridge

50 5.9 10.3 2.6 3.6 4484.4 4485.1

100 6.1 10.4 3.1 4.0 4484.9 4485.5

4.4.5 Site 4 Proposed Conditions

The proposed structure for Site 4 is a 110’ long bridge with an approximate low chord elevation of 4486.5’ located at the south crossing. The north crossing is not required for hydraulic capacity and is recommended to be remain in place, but no conveyance through this culvert is assumed in the hydraulic model. The proposed bridge has spill-through abutments and an approximate 78’ waterway width. The existing roadway grade will be raised to accommodate the hydraulic capacity requirements. Figure 14 shows a comparison between proposed and existing water surface profiles in the vicinity of the bridge for the 50-year design frequency. Figure 15 compares the 50-year inundation limits between the existing and

Overtopping

Existing Culvert Proposed Bridge

Proposed roadway alignment

Page 23 NM FLAP SIE10(1) Lakeshore Road – Final Hydraulics Report proposed conditions. The proposed culvert eliminates the roadway overtopping that was estimated for the 50-year existing conditions model.

Figure 14: Site 4 50-Year Water Surface Profile (Proposed vs Existing)

Existing

Proposed Bridge

Existing roadway to be removed

Page 24 NM FLAP SIE10(1) Lakeshore Road – Final Hydraulics Report

Figure 15: Site 4 50-Year Water Surface Elevation (Proposed vs Existing)

Pertinent 50-year and 100-year hydraulic results for the proposed bridge are shown in Table 15. The table shows average and maximum hydraulic results at the upstream face of the proposed bridge and at a distance approximately one bridge width upstream.

Table 15: Site 3 50-year and 100-year Proposed Conditions Hydraulic Results

Location Return Period (year) Velocity (ft/s) Depth (ft) WSEL (ft)

Average Maximum Average Maximum Average Maximum

Upstream Bridge Face

50 7.1 9.8 3.5 4.6 4458.4 4459.1 100 7.2 10.2 3.6 5.3 4458.8 4459.8

Approximately 35’ Upstream of Bridge

50 8.1 12.7 4.1 5.1 4459.4 4460.4

100 8.4 13.2 4.8 5.7 4460.1 4461.0

Existing Culvert Proposed Bridge

Existing culvert to remain bridge

Page 25 NM FLAP SIE10(1) Lakeshore Road – Final Hydraulics Report

4.5 BRIDGE SCOUR ASSESSMENT

Bridge scour was evaluated for Site 3 and Site 4 in accordance with HEC-18 (Federal Highway Administration 2012) for the 100-year scour design flood and the 200-year scour check flood. Total scour is the combination of long-term degradation, contraction scour and local scour (abutment scour). For this study, abutment scour was estimated using the NCHRP 24-20 method.

4.5.1 Geotechnical Investigation

The geotechnical investigation was conducted in January 2021. Streambed materials at both sites are generally classified as poorly graded sand with silt and gravel (SP-SM). A gradation analysis of streambed material was conducted as part of the geotechnical investigation documented in the project Geotechnical Report. Based on the laboratory results the median particle sizes (D50) are 2 mm (0.007 ft) and 0.6 mm (0.002 ft) for Site 3 and Site 4, respectively. Additional details can be found in the project Geotechnical Report.

4.5.2 Site 3 Scour Estimates

Long term degradation was estimated using an equilibrium slope analysis based on 2-year channel hydraulics. Base level control was approximated 1,800 feet downstream of the bridge using aerial photographs showing reservoir stage influence at this distance.

Contraction scour can occur under two conditions: live-bed and clear-water. Live-bed scour occurs when there is sediment transport of bed material from the upstream reach into the bridge section. Clear-water scour occurs when there is no transport of bed material into the bridge section. The applicable scour case is determined by comparing the mean velocity of the channel with the critical velocity for initiation of motion using the median size (D50) of the streambed materials. Based on the materials observed on site and the results of the geotechnical investigation a live bed scour condition can be expected. A summary of contraction scour depths is shown in Table 16.

Table 16: Site 3 Contraction Scour Estimates

Parameter 100-Year 200-Year D50 (ft) 0.007

Average Flow Depth Upstream of Contraction(ft) 2.79 3.14

Critical Velocity (ft/s) 2.49 2.54 Average Velocity Upstream (ft/s) 8.37 8.72

Scour Condition Live Bed Live Bed Contraction Scour Depth (ft) 0.98 1.20

Adopted Contraction Scour Depth (ft) 0.98 1.20

Abutment scour was estimated using the NCHRP 24-20 method which applies an amplification factor to the contraction scour at the abutments, i.e. it includes contraction scour at each abutment as part of the estimate. A type a (main channel) scour condition was assumed in accordance with HEC-18. A summary of abutment scour depths is shown in Table 17.

Page 26 NM FLAP SIE10(1) Lakeshore Road – Final Hydraulics Report

Table 17: Site 3 Abutment Scour Estimates

Parameter Left Abutment Right Abutment

100-Year 200-Year 100-Year 200-Year D50 (ft) 0.007 0.007 q2/q1 1.25 1.35 1.25 1.35 Amplification Factor 1.68 1.65 1.68 1.65

Average Velocity Upstream (ft/s) 8.37 8.72 8.37 8.72 Scour Condition Type a Live Bed Type a Live Bed Type a Live Bed Type a Live Bed

Abutment Scour Depth (ft) 3.75 4.22 2.92 3.62 Adopted Abutment Scour Depth (ft) 3.75 4.22 2.92 3.62

It is recommended that the maximum scour elevations are applied to both abutments and that they are referenced to the channel thalweg. A summary of total scour depths and recommended scour elevations are shown in Table 18.

Table 18: Site 3 Total Scour Results

Design Flood Long Term

Degradation (ft)

Contraction Scour (ft)

Abutment Scour (ft)*

Total Scour

(ft)

Thalweg Elevation (ft)

Total Scour Elevation (ft)

100-year Scour Design

Flood

4.1 1.0 3.8 7.9 4,479.0 4,471.1

200-year Scour Check

Flood

4.1 1.2 4.2 8.3 4,479.0 4,470.7

*Includes contraction scour per NCHRP 24-20 method.

Class 5 riprap embankment abutment protection in accordance with HEC-23 Design Guideline 14 (Federal Highway Administration 2009) is recommended. The riprap apron should extend a minimum of 6 feet from the toe of the abutment.

4.5.3 Site 4 Scour Estimates

Long term degradation was estimated using an equilibrium slope analysis based on 2-year channel hydraulics. Base level control was approximated 1,000 feet downstream of the bridge using aerial photographs showing reservoir stage influence at this distance.

Contraction scour was estimated for both live-bed and clear-water conditions. Based on the materials observed on site and the results of the geotechnical investigation a live bed scour condition can be expected. A summary of contraction scour depths is shown in Table 19.

Table 19: Site 4 Contraction Scour Estimates

Parameter 100-Year 200-Year D50 (ft) 0.002

Page 27 NM FLAP SIE10(1) Lakeshore Road – Final Hydraulics Report

Average Flow Depth Upstream of Contraction(ft) 1.64 1.91

Critical Velocity (ft/s) 1.53 1.57 Average Velocity Upstream (ft/s) 4.72 5.19

Scour Condition Live Bed Live Bed Contraction Scour Depth (ft) 0.73 0.91

Adopted Contraction Scour Depth (ft) 0.73 0.91

Abutment scour was estimated using the NCHRP 24-20 method which applies an amplification factor to the contraction scour at the abutments, i.e. it includes contraction scour at each abutment as part of the estimate. A type a (main channel) scour condition was assumed in accordance with HEC-18. A summary of abutment scour depths is shown in Table 20.

Table 20: Site 4 Abutment Scour Estimates

Parameter Left Abutment Right Abutment

100-Year 200-Year 100-Year 200-Year D50 (ft) 0.002 0.002 q2/q1 4.08 4.05 4.09 4.09 Amplification Factor 1.1 1.1 1.1 1.1

Average Velocity Upstream (ft/s) 4.72 4.72 5.19 5.19 Scour Condition Type a Live Bed Type a Live Bed Type a Live Bed Type a Live Bed

Abutment Scour Depth (ft) 3.71 1.61 4.53 1.88 Adopted Abutment Scour Depth (ft) 3.71 1.61 4.53 1.88

It is recommended that the maximum scour elevations are applied to both abutments and that they are referenced to the channel thalweg. A summary of total scour depths and recommended scour elevations are shown in Table 21

Table 21: Site 4 Total Scour Results

Design Flood Long Term

Degradation (ft)

Contraction Scour (ft)

Abutment Scour (ft)*

Total Scour

(ft)

Thalweg Elevation (ft)

Total Scour Elevation (ft)

100-year Scour Design

Flood

6.5 0.7 3.7 10.2 4,454.5 4,444.3

200-year Scour Check

Flood

6.5 0.9 4.5 11.0 4,454.5 4,443.5

*Includes contraction scour per NCHRP 24-20 method.

Class 3 riprap embankment abutment protection in accordance with HEC-23 Design Guideline 14 (Federal Highway Administration 2009) is recommended. The riprap apron should extend a minimum of 6 feet from the toe of the abutment.

Page 28 NM FLAP SIE10(1) Lakeshore Road – Final Hydraulics Report

4.6 SITE 5 LOW WATER CROSSING

The existing low water crossing (LWC) at Site 5 will be improved by providing a concrete surface and riprap protection. The length of the LWC concrete surface and riprap protection was estimated using an SRH-2D hydraulic model and the 2-year design flow of 181 cfs, as shown in Figure 16. The resulting LWC limits are from station 501+50 to 503+50 for a total 180 feet concrete surface. The 25-year design flow of 694 cfs was used to size the riprap overtopping protection in accordance with HEC-23 Design Guideline 5 (Federal Highway Administration 2009). Based on this guideline Class 3 riprap is recommended.

Figure 16: Site 5 2-Year Water Surface Extents

Page 29 NM FLAP SIE10(1) Lakeshore Road – Final Hydraulics Report

5 SUMMARY OF RECOMMENDATIONS

Hydrology and hydraulics analyses were conducted for the Lakeshore Road project. Based on the hydraulic capacity and stability requirements the structures shown in the following tables are proposed.

Table 22: Proposed Culverts for Site 1 and 2

Site Proposed Culvert (span x height)

Upstream Invert (ft)

Downstream Invert (ft)

Length

(ft) Remarks

Site 1 (2) 10' x 5' CBC 4449.4 4435.0 122 Energy dissipation provided by 28’ SAF stilling basin. Class 3 riprap apron downstream.

Site 2 (2) 10' x 5' CBC 4454.4 4449.1 123 Energy dissipation provided by a 26’ SAF stilling basin. Class 2 riprap apron downstream.

Table 23: Proposed Bridges for Site 3 and 4

Site Proposed Structure Low Chord Elevation (ft) Remarks

Site 3 70’ Bridge Length 4486.5 Class 3 riprap abutment protection, minimum 6-foot apron from toe of abutment.

Site 4 110' Bridge Length 4462.4 Class 3 riprap abutment protection, minimum 6-foot apron from toe of abutment.

Page 30 NM FLAP SIE10(1) Lakeshore Road – Final Hydraulics Report

6 REFERENCES

Aquaveo. 2019. Surface-water Modeling System (SMS), version 13.0.5. Provo, UT.

Federal Highway Administration . 2009. "Bridge Scour and Stream Instability Countermeasures - Experience, Selection, and Design Guidelines, Hydraulic Engineering Circular No. 23, Third Edition, FHWA-NHI 09-111 (Vol. 1), FHWA-NHI-09-112 (Vol. 2)." Federal Highway Administration, Washington, DC.

Federal Highway Administration. 2012. "Evaluating Scour at Bridges, Hydraulic Engineering Circular No.

18, Fifth Edition, FHWA-HIF-12-003." Washington D.C.

Federal Highway Administration. 2017. HY-8 Culvert Analysis Program. Version 7.50.

Federal Highway Administration. 2006. "Hydraulic Design of Energy Disspators for Culverts and Channels.

Hydraulic Engineering Circular No. 14, Third Edition, FHWA-NHI 06-086." Washington D.C.

Federal Lands Highway. 2012. "Project Development and Design Manual, Chapter 7 Hydrology and Hydraulics." https://flh.fhwa.dot.gov/resources/design/pddm/.

Multi-Resolution Land Characteristics Consortium . 2018. National Land Cover Database 2011 (NLCD 2011). Multi-Resolution Land Characteristics Consortium (MRLC).

https://data.nal.usda.gov/dataset/national-land-cover-database-2011-nlcd-2011.

National Oceanic and Atmospheric Administration. 2011. Precipitation Frequency Data Server (PFDS).

Silver Springs, MD. Accessed April 2019. https://hdsc.nws.noaa.gov/hdsc/pfds/index.html.

Natural Resources Conservation Service. 1997. "National Engineering Handbook, Part 630 Hydrology."

Washington, DC. https://directives.sc.egov.usda.gov/viewerFS.aspx?hid=21422.

Natural Resources Conservation Service. 2015. Soil Survey Geographic (SSURGO) database. Fort Worth, TX. Accessed April 2019. http://websoilsurvey.nrcs.usda.gov.

New Mexico Department of Transportation. 2018. "Drainage Design Manual."

https://dot.state.nm.us/content/dam/nmdot/Infrastructure/Drain_Design_Manual.pdf.

Perica, Sanja, Sarah Dietz, Sarah Heim, Lillian Hiner, Kazungu Maitaria, Deborah Martin, Sandra Pavlovic, et al. 2011. "Precipitation Frequency Atlas of the United States Volume 1 Version 5.0: Semiarid Southwest (Arizona, Southeast California, Nevada, New Mexico, Utah)." NOAA Atlas 14, Silver Spring, MD.

U.S. Army Corps of Engineers. 2017. HEC-HMS, Hydrologic Engineering Center Hydrologic Modeling System. Version 4.2.1. Davis, CA.

U.S. Bureau of Reclamation. 2017. SRH-2D, Sedimentation and River Hydraulics – Two-Dimensional model.

Version 3.2.

U.S. Geological Survey. 2016. StreamStats Program. http://streamstats.usgs.gov.

Page 31 NM FLAP SIE10(1) Lakeshore Road – Final Hydraulics Report

Waltenmeyer, Scott D. 2008. "Analysis of the Magnitude and Frequency of Peak Discharge and Maximum Observed Peak Discharge in New Mexico and Surrounding Areas." U.S. Geological Survey Scientific Investigations Report 2008-5119.

NM FLAP SIE10(1) Lakeshore Road – Final Hydraulics Report

Appendix A – Hydrologic Analyses

4/23/2020 StreamStats https://streamstats.usgs.gov/ss/ 1/3

Site 1 - Lakeshore Road

Basin Characteristics

Parameter Code Parameter Description Value Unit

DRNAREA Area that drains to a point on a stream 1.11 square miles

BSLDEM30ff Mean basin slope computed from 30 m DEM in feet per foot

0.073 percent

PRECIP Mean Annual Precipitation 10.2 inches

HIGHREG HIGHREG 1098 dimensionless

ELEV Mean Basin Elevation 4630 feet

I24H100YA2 Maximum 24-hour precipitation that occurs on average once in 100 years from NOAA Atlas 2

3.41 inches

Region ID: NM Workspace ID: NM20200423150504746000 Clicked Point (Latitude, Longitude): 33.21345, -107.22525 Time: 2020-04-23 09:05:21 -0600 https://streamstats.usgs.gov/ss/ 2/3

Parameter Code Parameter Description Value Unit

OUTLETELEV Elevation of the stream outlet in thousands of feet above NAVD88.

4448 feet

PREC10to4 Mean precipitation for winter period defined as October to April

3.57 inches

Peak-Flow Statistics Parameters[Peak 2008 5119 SW Desert Flood Region 7]

Parameter Code Parameter Name Value Units Min Limit Max Limit

DRNAREA Drainage Area 1.11 square miles 0.2 2820

HIGHREG HIGHREG 1098 dimensionless

Peak-Flow Statistics Flow Report[Peak 2008 5119 SW Desert Flood Region 7]

PIl: Prediction Interval-Lower, PIu: Prediction Interval-Upper, SEp: Standard Error of Prediction, SE:

Standard Error (other -- see report)

Statistic Value Unit SE SEp

2 Year Peak Flood 154 ft^3/s 63 63

5 Year Peak Flood 292 ft^3/s 48 48

10 Year Peak Flood 408 ft^3/s 41 41

25 Year Peak Flood 583 ft^3/s 38 38

50 Year Peak Flood 733 ft^3/s 37 37

100 Year Peak Flood 898 ft^3/s 38 38

500 Year Peak Flood 1350 ft^3/s 45 45

Peak-Flow Statistics Citations

Waltemeyer, S.D.,2008, Analysis of the Magnitude and Frequency of Peak Discharge and Maximum Observed Peak Discharge in New Mexico and Surrounding Areas: U.S. Geological Survey Scientific Investigations Report 2008-5119, 105 p.

(http://pubs.usgs.gov/sir/2008/5119/)

USGS Data Disclaimer: Unless otherwise stated, all data, metadata and related materials are considered to satisfy the quality standards relative to the purpose for which the data were collected. Although these data and associated metadata have been reviewed for accuracy and completeness and approved for release by the U.S. Geological Survey (USGS), no warranty http://pubs.usgs.gov/sir/2008/5119/ https://streamstats.usgs.gov/ss/ 3/3 expressed or implied is made regarding the display or utility of the data for other purposes, nor on all computer systems, nor shall the act of distribution constitute any such warranty.

USGS Software Disclaimer: This software has been approved for release by the U.S. Geological Survey (USGS). Although the software has been subjected to rigorous review, the USGS reserves the right to update the software as needed pursuant to further analysis and review. No warranty, expressed or implied, is made by the USGS or the U.S. Government as to the functionality of the software and related material nor shall the fact of release constitute any such warranty. Furthermore, the software is released on condition that neither the USGS nor the U.S. Government shall be held liable for any damages resulting from its authorized or unauthorized use.

USGS Product Names Disclaimer: Any use of trade, firm, or product names is for descriptive purposes only and does not imply endorsement by the U.S. Government.

Application Version: 4.3.11

5/21/2020 StreamStats

Site 2 North Basin

Basin Characteristics

Parameter Code Parameter Description Value Unit

DRNAREA Area that drains to a point on a stream 0.44 square miles

BSLDEM30ff Mean basin slope computed from 30 m DEM in feet per foot

0.1 percent

PRECIP Mean Annual Precipitation 10.1 inches

HIGHREG HIGHREG 1098 dimensionless

ELEV Mean Basin Elevation 4580 feet

I24H100YA2 Maximum 24-hour precipitation that occurs on average once in 100 years from NOAA Atlas 2

3.38 inches

Region ID: NM Workspace ID: NM20200521192646543000 Clicked Point (Latitude, Longitude): 33.22994, -107.21426 Time: 2020-05-21 13:27:03 -0600

Parameter Code Parameter Description Value Unit

OUTLETELEV Elevation of the stream outlet in thousands of feet above NAVD88.

4457 feet

PREC10to4 Mean precipitation for winter period defined as October to April

3.54 inches

Peak-Flow Statistics Parameters[Peak 2008 5119 SW Desert Flood Region 7]

Parameter Code Parameter Name Value Units Min Limit Max Limit

DRNAREA Drainage Area 0.44 square miles 0.2 2820

HIGHREG HIGHREG 1098 dimensionless

Peak-Flow Statistics Flow Report[Peak 2008 5119 SW Desert Flood Region 7]

PIl: Prediction Interval-Lower, PIu: Prediction Interval-Upper, SEp: Standard Error of Prediction, SE:

Standard Error (other -- see report)

Statistic Value Unit SE SEp

2 Year Peak Flood 101 ft^3/s 63 63

5 Year Peak Flood 189 ft^3/s 48 48

10 Year Peak Flood 262 ft^3/s 41 41

25 Year Peak Flood 371 ft^3/s 38 38

50 Year Peak Flood 462 ft^3/s 37 37

100 Year Peak Flood 562 ft^3/s 38 38

500 Year Peak Flood 826 ft^3/s 45 45

Peak-Flow Statistics Citations

Waltemeyer, S.D.,2008, Analysis of the Magnitude and Frequency of Peak Discharge and Maximum Observed Peak Discharge in New Mexico and Surrounding Areas: U.S. Geological Survey Scientific Investigations Report 2008-5119, 105 p.

(http://pubs.usgs.gov/sir/2008/5119/)

USGS Data Disclaimer: Unless otherwise stated, all data, metadata and related materials are considered to satisfy the quality standards relative to the purpose for which the data were collected. Although these data and associated metadata have been reviewed for accuracy and completeness and approved for release by the U.S. Geological Survey (USGS), no warranty expressed or implied is made regarding the display or utility of the data for other purposes, nor on all computer systems, nor shall the act of distribution constitute any such warranty.

USGS Software Disclaimer: This software has been approved for release by the U.S. Geological Survey (USGS). Although the software has been subjected to rigorous review, the USGS reserves the right to update the software as needed pursuant to further analysis and review. No warranty, expressed or implied, is made by the USGS or the U.S. Government as to the functionality of the software and related material nor shall the fact of release constitute any such warranty. Furthermore, the software is released on condition that neither the USGS nor the U.S. Government shall be held liable for any damages resulting from its authorized or unauthorized use.

USGS Product Names Disclaimer: Any use of trade, firm, or product names is for descriptive purposes only and does not

Site 2 South Basin

Basin Characteristics

Parameter Code Parameter Description Value Unit

DRNAREA Area that drains to a point on a stream 0.14 square miles

BSLDEM30ff Mean basin slope computed from 30 m DEM in feet per foot

0.0707 percent

PRECIP Mean Annual Precipitation 10.1 inches

HIGHREG HIGHREG 1098 dimensionless

ELEV Mean Basin Elevation 4550 feet

I24H100YA2 Maximum 24-hour precipitation that occurs on average once in 100 years from NOAA Atlas 2

3.39 inches

Region ID: NM Workspace ID: NM20200521193122170000 Clicked Point (Latitude, Longitude): 33.22939, -107.21425 Time: 2020-05-21 13:31:41 -0600

Peak-Flow Statistics Parameters[Peak 2008 5119 SW Desert Flood Region 7]

Parameter Code Parameter Name Value Units Min Limit Max Limit

DRNAREA Drainage Area 0.14 square miles 0.2 2820

HIGHREG HIGHREG 1098 dimensionless

Peak-Flow Statistics Disclaimers[Peak 2008 5119 SW Desert Flood Region 7]

One or more of the parameters is outside the suggested range. Estimates were extrapolated with unknown errors

Peak-Flow Statistics Flow Report[Peak 2008 5119 SW Desert Flood Region 7]

Statistic Value Unit

2 Year Peak Flood 60 ft^3/s

5 Year Peak Flood 111 ft^3/s

10 Year Peak Flood 152 ft^3/s

25 Year Peak Flood 212 ft^3/s

50 Year Peak Flood 262 ft^3/s

100 Year Peak Flood 315 ft^3/s

500 Year Peak Flood 451 ft^3/s

Peak-Flow Statistics Citations

Waltemeyer, S.D.,2008, Analysis of the Magnitude and Frequency of Peak Discharge and Maximum Observed Peak Discharge in New Mexico and Surrounding Areas: U.S. Geological Survey Scientific Investigations Report 2008-5119, 105 p.

(http://pubs.usgs.gov/sir/2008/5119/)

USGS Data Disclaimer: Unless otherwise stated, all data, metadata and related materials are considered to satisfy the quality standards relative to the purpose for which the data were collected. Although these data and associated metadata have been reviewed for accuracy and completeness and approved for release by the U.S. Geological Survey (USGS), no warranty expressed or implied is made regarding the display or utility of the data for other purposes, nor on all computer systems, nor shall the act of distribution constitute any such warranty.

USGS Software Disclaimer: This software has been approved for release by the U.S. Geological Survey (USGS). Although the software has been subjected to rigorous review, the USGS reserves the right to update the software as needed pursuant to further analysis and review. No warranty, expressed or implied, is made by the USGS or the U.S. Government as to the functionality of the software and related material nor shall the fact of release constitute any such warranty. Furthermore, the software is released on condition that neither the USGS nor the U.S. Government shall be held liable for any damages resulting from its authorized or unauthorized use.

USGS Product Names Disclaimer: Any use of trade, firm, or product names is for descriptive purposes only and does not

Site 3 - Lakeshore Road

Basin Characteristics

Parameter Code Parameter Description Value Unit

DRNAREA Area that drains to a point on a stream 2.72 square miles

BSLDEM30ff Mean basin slope computed from 30 m DEM in feet per foot

0.0499 percent

PRECIP Mean Annual Precipitation 10.2 inches

HIGHREG HIGHREG 1098 dimensionless

ELEV Mean Basin Elevation 4730 feet

I24H100YA2 Maximum 24-hour precipitation that occurs on average once in 100 years from NOAA Atlas 2

3.38 inches

Region ID: NM Workspace ID: NM20200423161402180000 Clicked Point (Latitude, Longitude): 33.24140, -107.20253 Time: 2020-04-23 10:14:18 -0600

Parameter Code Parameter Description Value Unit

OUTLETELEV Elevation of the stream outlet in thousands of feet above NAVD88.

4478 feet

PREC10to4 Mean precipitation for winter period defined as October to April

3.58 inches

Peak-Flow Statistics Parameters[Peak 2008 5119 SW Desert Flood Region 7]

Parameter Code Parameter Name Value Units Min Limit Max Limit

DRNAREA Drainage Area 2.72 square miles 0.2 2820

HIGHREG HIGHREG 1098 dimensionless

Peak-Flow Statistics Flow Report[Peak 2008 5119 SW Desert Flood Region 7]

PIl: Prediction Interval-Lower, PIu: Prediction Interval-Upper, SEp: Standard Error of Prediction, SE:

Standard Error (other -- see report)

Statistic Value Unit SE SEp

2 Year Peak Flood 231 ft^3/s 63 63

5 Year Peak Flood…