Arcadis_Sunland Levee Repair Design Report_20220204.pdf

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SUNLAND PARK LEVEE REPAIR

DESIGN DOCUMENTATION REPORT

EAST LEVEE & WEST LEVEE SEGMENT

DOWNSTREAM OF COUNTRY CLUB BRIDGE

FINAL DESIGN

Contract No. IBM15D0001 Task Order No. IBM17T0010

February 04, 2022

SUNLAND PARK LEVEE REPAIR – EAST/WEST LEVEE Contract No. IBM15D0001 Design Documentation Report (100% Design Revision 2) Task Order No. IBM17T0010 February 2022 arcadis.com

SUNLAND PARK

LEVEE REPAIR -

EAST LEVEE & WEST

LEVEE SEGMENT

DOWNSTREAM OF C.C.

BRIDGE

Design Documentation Report

Final Design

Prepared for:

U.S. International Boundary and Water Commission

4191 North Mesa Street

El Paso, Texas 79902

Prepared by:

Arcadis U.S., Inc.

401 East Main Street, Suite 400

El Paso, Texas 79901

Tel 401 738 3887

Our Ref.:

30001942

Date:

February 04, 2022

This document is intended only for the use of the individual or entity for which it was prepared and may contain information that is privileged, confidential and exempt from disclosure under applicable law. Any dissemination, distribution or copying of this document is strictly prohibited.

TEXAS BOARD OF PROFESSIONAL

ENGINEERS

FIRM REGISTRATION NUMBER: F-533

Ardita Dushi, P.E.

Project Manager

Kirk Lowery, P.E.

Design Lead

Joel Mora, P.E.

Deputy Program Manager

February 2022

STATEMENT OF LIMITATIONS

This Document is for United States International Boundary and Water Commission (USIBWC) use only.

The scope of services performed within may not be appropriate to satisfy the needs of USIBWC on other projects or the needs of other users. Any use or reuse of this Document or the findings, conclusions, or recommendations presented herein is at the sole risk of the user. The design provided in this Document is based on the previous studies and the reports and references provided by USIBWC.

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Contents

Acronyms and Abbreviations ......................................................................................................................... v

1 Project Information

1.1 General

1.2 Project History

1.3 Scope of Work

1.4 Purpose of Design Documentation Report

1.5 Project Location

2 Existing conditions

2.1 Site Visit

2.2 Survey Data

3 Geotechnical

4 Hydrology and Hydraulics

4.1 Hydraulic Model

4.2 Channel Velocities

5 Project and FEMA Requirements

5.1 General

5.2 Levee and Geotechnical Design

5.3 Freeboard Requirements

5.4 Closures

5.5 Embankment Protection

5.6 Embankment and Foundation Stability

5.6.1 Seepage Analysis

5.6.2 Slope Stability Analysis

5.7 Settlement

5.8 Interior Drainage

5.9 Other Design Criteria for Unique Solutions

6 Civil Design

6.1 Levee Crossings

6.1.1 East Levee Borderland Bridge Transition

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6.1.2 East Levee Country Club Bridge Transition

6.1.3 East Levee Sunland Park Bridge Transition

6.1.4 East Levee Racetrack Bridge Transition

6.1.5 West Levee Country Club Bridge Transition

6.2 Proposed Levee

6.3 Ramps

6.4 Encroachments

6.5 Subsurface Utility Exploration

6.6 Road Crossings

7 Environmental Considerations

7.1 Environmentally Sensitive Areas

7.2 Culturally Sensitive Areas

7.3 Biological Resources

7.4 Natural Resources

7.5 Restoration Sites

8 Structural Design

8.1 Low Structures

8.2 Levee Closure Structures

8.3 Roadway Barrier Transitions at Country Club Bridge

8.4 Raising of Existing Concrete Wall

8.5 Vehicular Gates

9 Construction Considerations

9.1 Utility Conflicts

9.2 Construction Outside USIBWC’s ROW

9.3 Long Lead Time Items

9.4 Sole Source Items

9.5 Specialty Contractors

9.6 Estimated Time of Construction

9.7 Contractor’s Technical Requirements

9.8 Traffic Plan

10 Operation and Maintenance

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10.1 Operation and Maintenance for Levees

10.2 Operation and Maintenance of Stoplogs

10.2.1 Operation of Stoplogs

10.2.2 Maintenance of Stoplogs

11 References

TABLES

Table 1. Project Location Summary for Sunland Park Levees

Table 2. Major Crossings along Sunland Park Levees

Table 3. Existing Structures crossing Sunland Park Levees

Table 4. Existing Utilities along Sunland Park Levees

Table 5. Soil Properties used for Seepage Analysis

Table 6. Soil Properties used for Sunland Levees Slope Stability Analysis

Table 7. Slope Stability Results

Table 8. Proposed Levee 2.5H:1V Slope Sections

Table 9. Encroachments along Sunland Park Levees

Table 10. USIBWC Signs for Road Crossings

Table 11. Existing Low Structures on East and West Levees

Table 12. Vehicular Gates

Table 13. Monthly Rain Days for 0.1-inch Rain Event (Mean Values in El Paso area)

FIGURES

Figure 1. Sunland Park – East and West Levee Locations

Figure 2. Base Flood Elevations (BFE) along River Channel

Figure 3. Simulated Maximum Channel Velocities along River Channel

Figure 4. Steady-State Seepage Results East Levee with Toe Drains (from Kenall 2016)

Figure 5. Exit Gradients at Levee Toe without Toe Drains – Transient Seepage (CE2 Sta. 1672+00)

Figure 6. Elevation Hydrograph at CE2 Sta. 1672+00

Figure 7. Flow Hydrograph at CE2 Sta. 1672+00

Figure 8. Typical Levee Section

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Figure 9. Typical Riprap Section

Figure 10. Country Club East Restoration Site [Reference: IDEALS-AGEISS (2020)]

Figure 11. Sunland Park Restoration Site [Reference:IDEALS-AGEISS (2020)]

Figure 12. Anapra Bridge Restoration Site [Reference: IDEALS-AGEISS (2020)]

Figure 13. Country Club East Levee – Stoplog along the width of the approach slab

Figure 14. Estimated Construction Schedule

APPENDICES

Appendix A - Photographic Logs

Appendix A.1 General Observations – Photographic Logs

Appendix A.2 Structures – Photographic Logs

Appendix B - Geotechnical Basis of Design

Appendix B.1 Geotechnical Memorandum

Appendix B.2 Seepage and Slope Stability

Appendix B.3 Settlement

Appendix B.4 Riprap Sizing

Appendix B.5 BFE and Freeboard Elevations

Appendix C - Structural Basis of Design

Appendix C.1 Low Structures

Appendix C.2 Levee Closure Alternatives

Appendix C.3 Levee Closure Structures

Appendix C.4 Wall Raise

Appendix D – Subsurface Utility Exploration

February 2022 arcadis.com v

ACRONYMS AND ABBREVIATIONS

Arcadis Arcadis U.S., Inc.

ASTM ASTM International

AT&T American Telephone & Telegraph

BFE Base Flood Elevation

CADD Computer Aided Design and Drafting

CFR Code of Federal Regulations

CoEP City of El Paso

CRRUA Camino Real Regional Utility Authority

CW2 Canutillo West 2

DDR Design Documentation Report

EPE El Paso Electric

EPW El Paso Water

FEMA Federal Emergency Management Agency fps Foot per second

FXSA Frank X. Spencer & Associates

Kenall Kenall, Inc.

MDJV Munoz and Dannenbaum Joint Venture

NAD 83 North American Datum of 1983

NAVD 88 North American Vertical Datum of 1988

NFIP National Flood Insurance Program

% percent

ROW Right-of-Way

S&BI S&B Infrastructure, Ltd.

SOW Scope of Work

SUE Subsurface Utility Exploration

SWCC Soil-Water Characteristic Curves

TGS Texas Gas Service

TxDOT Texas Department of Transportation

URGFCP Upper Rio Grande Flood Control Project

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USACE United States Army Corps of Engineers

USIBWC United States International Boundary and Water Commission

3D Three dimensional

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1 PROJECT INFORMATION

1.1 General

The United States Section of the International Boundary and Water Commission (USIBWC) contracted with Arcadis U.S., Inc. (Arcadis) for the design of the Sunland Park Levee Repair within the Rio Grande Canalization Project under Task Order No. IBM17T0010 of Contract No. IBM15D0001 to provide engineering services for the preparation of plans and specifications. In addition, Arcadis will support USIBWC during the project procurement and contracting process. The Sunland Park West Levee is known as the Canutillo West 2 (CW2) Levee and the Sunland Park East Levee is known as the Canutillo East 2 (CE2) Levee.

On September 15, 2018, USIBWC issued Contract Modification P00002 seeking to separate the construction documents into two packages: East Levee and West Levee. The design for the West Levee, except for the portion downstream of Country Club Bridge was submitted to USIBWC on August 26, 2019. On September 25, 2020, USIBWC issued Contract Modification P00005 seeking to combine the East Levee and West Levee portion downstream of Country Club Bridge into one construction package.

This report includes the improvements pertaining to Sunland Park Levee Repair for East Levee and West Levee downstream of Country Club Bridge.

The project team consists of Arcadis and the following subcontractors: Munoz and Dannenbaum Joint Venture (MDJV) and Frank X. Spencer & Associates (FXSA). Altogether, Arcadis and its subcontractors form the Arcadis Team.

1.2 Project History

In September 2010, the USIBWC issued a construction contract to rehabilitate the Sunland Park Levee segment of the Upper Rio Grande Flood Control Project (URGFCP). Construction was completed in November 2012. However, on completion, the levee experienced considerable erosion. The USIBWC contracted with Kenall, Inc. (Kenall) in April 2015 to perform a Forensic Geotechnical Investigation and provide the USIBWC a professional opinion on whether the newly constructed levee segment would perform satisfactorily during the 100-year flood event pursuant to 44 Code of Federal Regulations (CFR) §65.10 (Federal Emergency Management Agency [FEMA]). Kenall identified several construction-related problems, and its investigation found dispersive clay within the existing levee embankment along the entire length of this reach of the levee system. Kenall found that as a result of the erosion of the dispersive clay, the Sunland Park Levee Segment does not meet the National Flood Insurance Program (NFIP) Regulation 44 CFR §65.10(b).

Previous studies for the design of the Sunland Park Levees include:

“Sunland Park Levee Forensic Geotechnical Investigation” by Kenall, dated July 29, 2016.

“Design Report for Upper Rio Grande Flood Control Project, Sunland Park Canutillo Levee

Segment” by S&B Infrastructure, Ltd. (S&BI), dated July 23, 2010.

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“Final Technical Memorandum Volume I for Geotechnical Explorations of Levee System within the Rio Grande Canalization Project- Canutillo Levee Segment” by Raba-Kistner Consultants, Inc., dated December 22, 2008.

“Final Technical Memorandum Volume II for Geotechnical Explorations of Levee System within the Rio Grande Canalization Project- Canutillo Levee Segment” by Raba-Kistner Consultants, Inc., dated December 22, 2008.

1.3 Scope of Work

The scope of work (SOW) titled “Design Scope of Work, Rio Grande Canalization, Sunland Park Levee Repair in El Paso County, TX and Doña Ana County, NM,” dated March 2, 2017, was provided for this task order. The main project goals are to:

Address the deficiencies noted in Kenall’s forensic report.

Provide a design intended to produce levees that fully meet FEMA requirements for 44 CFR

§65.10(b) (1) through (7). The final design is also intended to meet the requirements included in the United States Army Corps of Engineers' (USACE) Engineering Manual 1110-2-1913.

Remove the existing floodgate gate at the Country Club Bridge (eastside) and design a new gate to withstand the 100-year flood.

Raise or modify the levee closure structures along the levee alignment that are too low to be operated during flood flows.

The revised SOW, dated August 6, 2018, for the Contract Modification P00002 included the following work:

Separate the construction documents into two packages:

1. Sunland Park Levee Repair – East Levee

2. Sunland Park Levee Repair – West Levee

Provide catwalk design for access to the low structures that are currently inaccessible during flood flows.

Provide boundary survey monuments within this project limit.

The final West Levee design upstream of Country Club Bridge was submitted in August 2019. The construction phase of this levee segment was awarded in September 2019. This Design Documentation Report (DDR) includes the design of the East Levee and West Levee portion downstream of Country Club Bridge per Contract Modification P00005 issued on September 25, 2020.

1.4 Purpose of Design Documentation Report

This Design Documentation Report (DDR) presents the basis for design for the levee segments and structural components for improvements pertaining to Sunland Park Levee Repair: East Levee and West Levee downstream of Country Club Bridge. DDR includes design assumptions and criteria, calculations, and design approach for all aspects of construction. The design provided in this DDR, which is detailed in the construction drawings and specifications, complies with industry standards and meets the applicable requirements of Subsections 1.2, Project Goal, and 1.5, Project Requirements, and Section 11, Regulatory Requirements, of the SOW.

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1.5 Project Location

The project is located within the United States on land owned or controlled by the USIBWC within its Rio Grande Canalization Project, in El Paso County, Texas, and Doña Ana County, New Mexico. A layout of the project is included on Figure 1.

Figure 1. Sunland Park – East and West Levee Locations

The general location, length, coordinates, and stationing for the Sunland Park Levee segments included in this DDR are summarized in Table 1.

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Table 1. Project Location Summary for Sunland Park Levees

Levee Segment

General Location Length

Starting Station (Sta.)

Ending Station (Sta.)

Starting Coordinates

Ending Coordinates

East Levee North of

Borderland Bridge to Montoya Drain

8.4 miles 1510+19.16 1956+50(1) 31º 53’ 16.7” N 106º 35’

53.4” W

31º 48’ 7.1” N 106º 32’ 54” W

West Levee

Upstream of Country Club

Bridge to Nemexas Drain

0.6 miles 1666+00 1698+00(1) 31º 50’ 47.7” N 106º 36’

24.4” W

31º 50’ 17” N 106º 36’ 23” W

Note: (1)Ending Sta. 1956+50 for East Levee (CE2) and 1698+00 for West Levee (CW2) was indicated in the SOW per Task Order IBM10C0018. Due to the change of the centerline alignment, our design dictates that the ending station for CE2 corresponds to Sta. 1956+25.86 and CW2 corresponds to Sta. 1697+74.24.

2 EXISTING CONDITIONS

2.1 Site Visit

The Arcadis team visited the entire East and West Levees on April 3, 2017 and October 11, 2017 to observe the levee and structure conditions. During the site visits, the Arcadis team observed the pertinent project features, the structures defined by USIBWC as deficient, and the ongoing maintenance activities at the crest of the levee. In general, at the time of the site visits, the existing top of levee consisted approximately 2-inch-thick gravel layer for vehicle access. Several access ramps are located throughout the alignment. In some cases, improvements on privately owned properties have encroached on the levee Right-of-Way (ROW) as described in Section 6.4. Several major and minor public roads intersect the levee segments. The major crossings along the East and West Levee alignments are included in Table 2. Photographic logs of the general observations are presented in Appendix A.1.

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Table 2. Major Crossings along Sunland Park Levees

The existing structures along the levee alignment are included in Table 3. Photographic logs and the locations of all the existing structures along the levee reach are included in Appendix A.2. The structure type and size along with survey data are included in the contract drawings.

Table 3. Existing Structures crossing Sunland Park Levees

Station Structure Description Structure Size Ownership

EAST LEVEE

1531+82 Montoya Lateral Siphon 3.5’ x 4’ Box

Culvert EPCWID1

1706+44 Nemexas Siphon

72” Diameter concrete culvert EBID

1761+95 Montoya Lateral WW#38 48” RCP EPCWID1

WEST LEVEE

1667+04 Schultz Lateral WW#35C 30” RCP EBID

Approximate Sta. Description Ownership

EAST LEVEE

1517+77 Borderland Bridge City of El Paso

1546+13 Artcraft Bridge Texas Department of Transportation

1667+08 Country Club Bridge City of El Paso

1906+68 Sunland Park Bridge New Mexico Department of Transportation

1933+03 Racetrack Bridge New Mexico Department of Transportation

1666+59 Country Club Bridge City of El Paso

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The known existing utilities are provided in Table 4. The utilities in Table 4 have been field verified using historical documentation and by contacting known utility owners in the area to verify utility locations. We do not anticipate any conflicts with utilities for any of the proposed improvements for this project. The contract documents will require the construction contractor to verify utilities before start of construction.

Table 4. Existing Utilities along Sunland Park Levees

Utility Station Description Owner Contact Information Notes Known

Conflict?

EAST LEVEE

1511+19 Railroad Tracks

BNSF

Railway

Co.

(915) 534-2364 805 S. Santa Fe St.

El Paso, TX 79901

NA No

1517+59 Overhead Electric

El Paso Electric

(EPE)

Raul Guel

(915) 543-4015 raul.guel@epelectric.com 100 N. Stanton St. Suite 171, El Paso, TX 79901

Runs parallel to Borderland Rd.

along the north edge of the bridge.

No

1518+08 Natural Gas Line

Texas Gas Service

(TGS)

Saul Magallanes saul.magallanes@onegas.com

(o) 915-682-7356

(c) 915-727-6131

4700 Pollard St., El Paso, TX 79930

6” Steel gas line encased in 10” steel south of

Borderland Rd.

Bridge with 3’ minimum cover

No

1519+64 Water Line El Paso Water

(EPW)

Amy Castner acastner@epwater.org

(915) 594-5647

OR

Al Quijano pquijano@epwater.org

1154 Hawkins Blvd. El Paso, TX 79925

36” Concrete H.P.

just south of

Borderland Rd. El.

3756 TOP

No

1543+57 Overhead Electric

El Paso Electric

(EPE)

Raul Guel

(915) 543-4015 raul.guel@epelectric.com 100 N. Stanton St. Suite 171, El Paso, TX 79901

North of Artcraft Rd. bridge - Runs parallel to OE 1543+87

No

1543+87 Overhead Electric

El Paso Electric

(EPE)

Raul Guel

(915) 543-4015 raul.guel@epelectric.com 100 N. Stanton St. Suite 171, El Paso, TX 79901

North of Artcraft Rd. bridge - Runs parallel to OE 1543+57

No

1545+48 Electrical Conduit

TXDOT Susan Ryde Susan.ryde@txdot.gov

(915) 790-4207

Attached to northside of Artcraft Rd. bridge

No

1570+80 Overhead Electric

El Paso Electric

(EPE)

Raul Guel

(915) 543-4015 raul.guel@epelectric.com

Runs parallel with east levee - Behind residences on Sixta Dr. between

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Utility Station Description Owner Contact Information Notes Known

Conflict?

100 N. Stanton St. Suite 171, El Paso, TX 79901

Ontiveros St. and Jardin Bello Ave.

1619+55 Sanitary Sewer

El Paso Water

(EPW)

Amy Castner acastner@epwater.org

(915) 594-5647

OR

Al Quijano pquijano@epwater.org

1154 Hawkins Blvd. El Paso, TX 79925

3729 TOP;

24" I.D. with 40"steel casing - Along Maime Rd.

No

1666+63 Electrical Conduit

City of El Paso (CoEP)

Basilio Ontiveros Traffic Signals Maintenance

Supervisor Communications

Streets & Maintenance ontiverosbx@elpasotexas.gov

Office: (915) 212-7075

3.5' at junction box, goes down about 6' as it approaches the levee. Attached to northside of Country Club Rd.

Bridge

No

1666+79 Overhead Electric

El Paso Electric

(EPE)

Raul Guel

(915) 543-4015 raul.guel@epelectric.com 100 N. Stanton St. Suite 171, El Paso, TX 79901

Runs parallel to Country Club Rd.

Bridge

No

1666+86 Water Line El Paso Water

(EPW)

Amy Castner acastner@epwater.org

(915) 594-5647

OR

Al Quijano pquijano@epwater.org

1154 Hawkins Blvd. El Paso, TX 79925

5 ft min cover. 12" A.C encased in steel pipe - North side of Country Club Bridge

No

1667+00 Fiber Optic Line

AT&T Shawn Sather OSP Planning & Engineering ss1038@att.com Cell: 915-342-3172 Ofc: 915-595-5118

4" Line, Fiber optic line attached to southside of Country Club Rd.

Bridge. 8.5’ from top of FO to MH cover. Contact AT&T to verify location

No

1667+00 Fiber Optic Line

AT&T Shawn Sather OSP Planning & Engineering ss1038@att.com Cell: 915-342-3172 Ofc: 915-595-5118

4" Line, Fiber optic line attached to southside of Country Club Rd.

Bridge. 8.5’ from top of FO to MH cover. Contact AT&T to verify location (South side of CC Bridge)

No

1667+06 Natural Gas Line

Texas Gas Service

(TGS)

Saul Magallanes saul.magallanes@onegas.com

(o) 915-682-7356

Line is attached to bridge. Elevation

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Utility Station Description Owner Contact Information Notes Known

Conflict?

(c) 915-727-6131 4700 Pollard St., El Paso, TX

79930 approaching the levee is unknown.

4" steel line, attached to southside of Country Club Rd.

Bridge

1667+42 Fiber Optic Line

AT&T Shawn Sather OSP Planning & Engineering ss1038@att.com Cell: 915-342-3172 Ofc: 915-595-5118

4” line, Attached to southside of Country Club Rd.

Bridge.

Approximately 8’ cover from top of conduit to MH cover. Contact AT&T to verify.

No

1667+48 Overhead Electric

El Paso Electric

(EPE)

Raul Guel

(915) 543-4015 raul.guel@epelectric.com 100 N. Stanton St. Suite 171, El Paso, TX 79901

Runs above southside of Country Club Rd.

Bridge

No

1687+00 Natural Gas Line

New Mexico Gas Co.

Gabriel Ortiz Operations Supervisor -

Southern Rio Grande Area Gabriel.Ortiz@nmgasco.com

O: (505) 697-5408 c: (915) 497-3485

350 Acosta Road, Anthony, NM 88021

3.5 feet cover.

Discovered during previous construction of East Levee toe drain

Yes

1701+23 Overhead Electric

El Paso Electric

(EPE)

Raul Guel

(915) 543-4015 raul.guel@epelectric.com 100 N. Stanton St. Suite 171, El Paso, TX 79901

Crosses Rio Grande and East levee from Santa Teresita Dr.

towards Rinconada Ln.

No

1706+33 Natural Gas Line

New Mexico Gas Co.

Gabriel Ortiz Operations Supervisor -

Southern Rio Grande Area Gabriel.Ortiz@nmgasco.com

O: (505) 697-5408 c: (915) 497-3485

350 Acosta Road, Anthony, NM 88021

3.5 ft from surface.

Parallel with east levee

No

1730+42 Natural Gas Line

New Mexico Gas Co.

Gabriel Ortiz Operations Supervisor -

Southern Rio Grande Area Gabriel.Ortiz@nmgasco.com

O: (505) 697-5408 c: (915) 497-3485

350 Acosta Road, Anthony, NM 88022

3.5 ft from surface.

Crosses levee, approx. 1730+42

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Utility Station Description Owner Contact Information Notes Known

Conflict?

1730+80 Natural Gas Line

New Mexico Gas Co.

Gabriel Ortiz Operations Supervisor -

Southern Rio Grande Area Gabriel.Ortiz@nmgasco.com

O: (505) 697-5408 c: (915) 497-3485

350 Acosta Road, Anthony, NM 88021

3.5 ft from surface.

Discovered during previous construction of East Levee toe drain

Yes

1735+69 Overhead Electric

El Paso Electric

(EPE)

Raul Guel

(915) 543-4015 raul.guel@epelectric.com 100 N. Stanton St. Suite 171, El Paso, TX 79902

South of La Mancha Ct.

No

1761+65 Overhead Electric

El Paso Electric

(EPE)

Raul Guel

(915) 543-4015 raul.guel@epelectric.com 100 N. Stanton St. Suite 171, El Paso, TX 79903

Runs parallel along west side of 48" Montoya Lateral

No

1762+67 Water Line CRRUA Brent Westmoreland Executive Director brentw@donaanacounty.org

(575) 589-1075

4950 McNutt Rd. P.O. Box

Sunland Park, NM 88063

Approximately 3 ft cover. Crosses east levee, adjacent to 48" culvert (Sta.

1761+95), west of Equestrian Ln.

No

1807+35 Water Line CRRUA Brent Westmoreland Executive Director brentw@donaanacounty.org

(575) 589-1075

4950 McNutt Rd. P.O. Box

Sunland Park, NM 88063

4’ min cover. 10" WL - crosses east levee behind residences on Apaloosa Dr.

No

1811+95 Overhead Electric

El Paso Electric

(EPE)

Raul Guel

(915) 543-4015 raul.guel@epelectric.com 100 N. Stanton St. Suite 171, El Paso, TX 79903

Crosses east levee behind residences on Apaloosa Dr.

No

1812+62 Water Line CRRUA Brent Westmoreland Executive Director brentw@donaanacounty.org

(575) 589-1075

4950 McNutt Rd. P.O. Box

Sunland Park, NM 88063

6" WL - parallel with east levee, behind residences on Apaloosa Dr.

before crossing levee at approx.

1812+62. Approx.

@ 3733

No

1812+80 Water Line CRRUA Brent Westmoreland Executive Director brentw@donaanacounty.org

(575) 589-1075

4950 McNutt Rd. P.O. Box

Sunland Park, NM 88063

Approx. 3’ cover. 6" WL - parallel with east levee near to drain

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Utility Station Description Owner Contact Information Notes Known

Conflict?

1830+50 Water Line El Paso Electric

(EPE)

Raul Guel

(915) 543-4015 raul.guel@epelectric.com 100 N. Stanton St. Suite 171, El Paso, TX 79903

24" WL – turns downriver along the levee riverward toe and continues to the Rio Grande Power Plant.

No

1836+00 Water Line CRRUA Brent Westmoreland Executive Director brentw@donaanacounty.org

(575) 589-1075

4950 McNutt Rd. P.O. Box

Sunland Park, NM 88063

Approx. 3’ cover. 6” PVC line discovered during previous construction of East Levee toe drain, crosses levee at 1836+00

Yes

1839+61 Water Line CRRUA Brent Westmoreland Executive Director brentw@donaanacounty.org

(575) 589-1075

4950 McNutt Rd. P.O. Box

Sunland Park, NM 88063

3’ cover. 6” PVC line discovered during previous construction of East Levee toe drain

Yes

1840+83 Fiber Optic Line

AT&T Shawn Sather OSP Planning & Engineering ss1038@att.com Cell: 915-342-3172 Ofc: 915-595-5118

4700 Pollard St., El Paso, TX 79930

Approx. @ 3735.

Crosses East Levee at Frontera Rd.

No

1840+92 Overhead Electric

El Paso Electric

(EPE)

Raul Guel

(915) 543-4015 raul.guel@epelectric.com 100 N. Stanton St. Suite 171, El Paso, TX 79903

Crosses East levee at Frontera Rd

No

1932+38 Sanitary Sewer

CRRUA Brent Westmoreland Executive Director brentw@donaanacounty.org

(575) 589-1075

4950 McNutt Rd. P.O. Box

Sunland Park, NM 88063

Approx. 3’ cover.

Crosses east levee road on the west side of Racetrack Dr. bridge

No

1932+65 Natural Gas Line

New Mexico Gas Co.

Gabriel Ortiz Operations Supervisor -

Southern Rio Grande Area Gabriel.Ortiz@nmgasco.com

O: (505) 697-5408 c: (915) 497-3485

350 Acosta Road, Anthony, NM 88021

Approx. 2.5’ from top of NW side of bridge. Runs along west side of Racetrack Dr.

No

1932+77 Electrical Conduit

Verizon Bruce Turkiewicz; Engr IV Spec-Ntwk Eng & Ops

O: (915) 519 - 3362 c: (254) 721 - 8977

Runs along west edge of Racetrack Dr. Bridge. Approx.

@ 3742.7

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Utility Station Description Owner Contact Information Notes Known

Conflict?

4045 Doniphan Park Circle El Paso, TX 79922

1933+31 Fiber Optic

Line Verizon Manny Armendariz

Technician manny.armendariz@one.veriz on.com

Approx. 4 ft deep, shallower at MHs.

3" FOC - south edge of racetrack drive bridge

No

1933+39 Water Line CRRUA Brent Westmoreland Executive Director brentw@donaanacounty.org

(575) 589-1075

4950 McNutt Rd. P.O. Box

Sunland Park, NM 88063

4’ min cover.

12" WL - runs along east side of Racetrack Dr.

bridge

1956+95 Water Line El Paso Electric

(EPE)

Raul Guel

(915) 543-4015 raul.guel@epelectric.com 100 N. Stanton St. Suite 171, El Paso, TX 79903

24" WL - above grade vertical offset crossing the Montoya drain riverward of the levee culvert headwall

No

1666+38 Water Line EPW

Amy Castner acastner@epwater.org

(915) 594-5647

OR

Al Quijano pquijano@epwater.org

1154 Hawkins Blvd. El Paso, TX 79925

12" A.C encased in steel pipe. 5’ min cover.

No

1666+77 Fiber Optic Line

City of El Paso

Victor Pereda PeredaVM@elpasotexas.gov

(915) 472-3549

OR

Basilio Ontiveros Ontiverosbx@elpasotexas.gov

(915) 212-7075

3.5’ deep at JBE and drops 6’ as it approaches the levee. 4” Line attached to upstream side of Country Club Bridge and then parallel to the road

No

1666+83 Fiber Optic

AT&T

Shawn Sather OSP Planning & Engineering ss1038@att.com Cell: (915) 342-3172 Ofc: (915) 595-5118

8’ min cover at MH.

4" Line. Contact AT&T to verify location.

No

1666+82 Overhead

EPE

Raul Guel

(915) 543-4015 raul.guel@epelectric.com

Runs above downstream of Country Club Rd.

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Utility Station Description Owner Contact Information Notes Known

Conflict?

100 N. Stanton St. Suite 171 El Paso, TX 79901 and continues parallel to the road

1667+17 Natural Gas

TGS

Saul Magallanes saul.magallanes@onegas.com

(o) (915) 682-7356

(c) (915) 727-6131

4700 Pollard St., El Paso, TX 79930

4” aboveground steel line, attached to downstream of Country Club Bridge and then parallel to the road.

Approx. at El 3752.

No

1667+36 Electrical Conduit

AT&T

Shawn Sather OSP Planning & Engineering ss1038@att.com Cell: (915) 342-3172 Ofc: (915) 595-5118

Attached to downstream of Country Club Rd.

Bridge and then parallel to the road.

About 8 ft deep at the manhole. El at

No

1667+36 Electrical Conduit

AT&T Shawn Sather OSP Planning & Engineering ss1038@att.com Cell: (915) 342-3172 Ofc: (915) 595-5118

Attached to downstream of Country Club Rd.

Bridge and then parallel to the road.

About 8 ft deep at the manhole. El at

No

1696+82 Overhead

EPE

Raul Guel

(915) 543-4015 raul.guel@epelectric.com 100 N. Stanton St. Suite 171

El Paso, TX 79901

Runs parallel to the levee and crosses the levee at Sta.

1696+83.

No

2.2 Survey Data

FXSA performed surveying services including topographic and boundary surveys of the USIBWC’s ROW.

The topographic survey and the boundary survey for both east and west levees were performed from November 2017 through February 2018 and from November 2017 through April 2018, respectively. The coordinates, bearings, and distances on the topographic and boundary surveys are based on the New Mexico Coordinate System of 1983, North American Datum of 1983 (NAD 83) (2011), Central Zone (3002). These are shown as grid distances and may be converted to surface distances by dividing by the combined scale factor of 0.99973833. The elevations for this project are based on the North American Vertical Datum of 1988 (NAVD 88), Geoid 2012B. The field survey included performing cross-section surveys along the levee alignment at 100-foot intervals for the entire project reach. The survey data were processed to generate a topographic map with elevation contours using Autodesk Civil 3D Software.

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3 GEOTECHNICAL

A geotechnical memorandum describing the geotechnical basis of design is included in Appendix B.1. It should be noted that this geotechnical memorandum includes evaluations of both east and west levees per the original SOW.

4 HYDROLOGY AND HYDRAULICS

4.1 Hydraulic Model

USIBWC provided the hydraulic model within the project limits. The SOW specified the use of the 2005 FLO-2D model developed by Tetra Tech. During the project, it was determined that the 2005 model provided was not running correctly; therefore, USIBWC provided us with a 2009 FLO-2D model. We used the 2009 USIBWC FLO-2D model to determine the effects of levee improvements on base flood elevations (BFE) and velocities. The BFE in this model indicates the 100-year flood condition. The BFEs extracted from the 2009 model were used as the basis for determining the required freeboard elevations under the 100-year flood condition.

The model was used to check that the project improvements to the existing levee would not have any impact on the hydraulic conditions. The current model and the required +3 feet freeboard requirements are shown on Figure 2. The required project levee elevations are based on the top of the new embankment fill and below the aggregate roadway as presented in the contract drawings. At the bridge locations, FEMA’s minimum freeboard required is 4 feet within 100 feet of the bridge. However, based on a prior agreement between USIBWC and FEMA, the minimum freeboard required is 3 feet within 100 feet of the bridge. A table showing the station number, BFE and freeboard elevations is presented in Appendix B.5.

Figure 2. Base Flood Elevations (BFE) along River Channel

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4.2 Channel Velocities

The estimated channel velocities for the 100-year flood extracted from the 2009 FLO-2D model are shown on Figure 3. Estimated velocities in the Rio Grande channel along the Sunland Park East Levee range from 2.89 feet per second (fps) to 9.64 fps. High channel velocities over 9 fps were encountered at the Borderland Bridge and at the Country Club Bridge locations. Channel velocities higher than 6 fps were encountered between Sta. 1695+00 and Sta. 1713+00 on East Levee and downstream of Sta.

1696+00 on the West Levee. It appears that the increase in the velocities at this portion of the levee reflects the narrower channel width. Riprap will be placed on the riverside levee slopes at these locations as shown on the contract drawings. The Racetrack Bridge also indicated velocities slightly higher than 6 fps. No remediation is planned at this location since bridge abutments are covered with wire encased stone riprap.

The difference between the velocities presented on Figure 3 and the velocities presented in Kenall’s 2016 report are likely due to the different hydraulic models used in the previous design and our design. The previous design was based on the USIBWC 2003 Hydraulic Model, and we used the USIBWC 2009 FLO- 2D Model for our design.

Figure 3. Simulated Maximum Channel Velocities along River Channel

5 PROJECT AND FEMA REQUIREMENTS

5.1 General

The design objectives for this project are to meet FEMA requirements in 44 CFR §65.10(b) (1) through (7), which include: 1) freeboard, 2) closures, 3) embankment protection, 4) embankment and foundation stability, 5) settlement, 6) interior drainage, and 7) other design criteria for unique situations. The new levee should also meet the requirements of the USACE’s Engineering Manual 1110-2-1913 titled "Design

February 2022 arcadis.com and Construction of Levees" (USACE 2000). This section describes the project requirements and basic design criteria for the project.

The SOW for this project required addressing the deficiencies noted in Kenall’s forensic report (Kenall 2016). After a review and evaluation of Kenall’s forensic study, we found other issues that are not in conformance with the FEMA requirements based on the most recent survey and the 2009 FLO-2D model:

1) there is inadequate freeboard up to 10 inches at some locations along the alignment as described in Section 6; 2) there is inadequate freeboard in some locations near structures as described in more detail in Section 6.1; and 3) there are higher channel velocities than those reported in Kenall’s report as described in Section 4.2.

5.2 Levee and Geotechnical Design

The levee design criteria are based on addressing the dispersive clay that exists throughout the levee reach as identified by Kenall. To establish the earthwork design criteria, we evaluated 11 alternatives for treatment of dispersive clay as described more fully in Appendix B.1. Following the design scoping meeting held on December 13, 2017, the USIBWC selected the clay blanket option; thus, dispersive clay would be replaced with imported, non-dispersive compacted clay. This alternative will address the deficiencies regarding dispersive clay noted in the forensic report by Kenall.

This alternative, as originally presented by Kenall, involves excavating at least 2 feet of the existing dispersive clay soil and replacing it with imported clay that is not dispersive. The imported clay will be moisture-conditioned and compacted to achieve a well-constructed envelope of non-dispersive soil around the core of the existing levee, which may contain dispersive clay. The dispersive clay at the levee core will be isolated, reducing the threat of internal or external erosion.

The imported non-dispersive clay borrow should classify as CL in accordance with ASTM International (ASTM) D2487, Unified Soil Classification System, with a plasticity index between 15 to 30 and a maximum liquid limit of 45 percent (%). Fat clay should not be used due to the higher susceptibility to desiccation cracking.

The clay borrow must be non-dispersive and meet the testing requirements listed below:

Crumb Test (ASTM D6572) - Grade 1 (non-dispersive)

Pinhole Test (ASTM D4647) - ND1 or ND2

Double Hydrometer (ASTM D4221) – Percent dispersive less than 30

At least 65% passing a U.S. Standard No. 200 sieve

One hundred percent (100%) of the dry material passing the 1-inch sieve

Contain less than 35% sand content by weight.

The embankment fill will be compacted to at least 95% of maximum density at a moisture content above optimum moisture content as determined by ASTM D698, Standard Proctor. Other levee and geotechnical design criteria include:

Freeboard will be at least 3 feet above the BFE. The gravel road on the levee will not be included as part of the 3-foot freeboard requirement.

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The levee footprint will not be moved from its currently existing alignment.

The levee slopes horizontal:vertical (H:V) will be 2.5H:1V or flatter (USIBWC prefers 3H:1V slopes where possible).

The finished gravel road will be at least 16 feet wide and a minimum of 6 inches thick. The maintenance roadway will slope toward the riverside at 2% along the alignment.

Ramps along the levee will be designed as shown in the SOW.

Dispersive clays will not be used in construction.

Results of seepage analysis will be incorporated into stability analysis.

Soil properties are based on the previous studies provided by USIBWC.

Factors of safety will meet the USACE requirements.

Sections 5.3 through 5.9 were considered in the design to satisfy the FEMA and USACE requirements.

5.3 Freeboard Requirements

We designed the final elevation of the non-dispersive clay cap to be at least 3 feet above the BFE (100-year flood). The BFE is extracted from the 2009 FLO-2D model provided by USIBWC. The landside will be slightly higher due to the 2% cross-slope requirements. The gravel roadway is not included in the freeboard requirements. At the bridge locations, FEMA requires the minimum freeboard to be at least 4 feet within 100 feet of the bridge. However, based on a prior agreement of USIBWC with FEMA, the minimum freeboard required is 3 feet within 100 feet of the bridge. There are three bridge crossing locations (East Levee - South Borderland Bridge, East Levee - North Country Club, and West Levee - South Country Club Bridge) along the levee reaches where the levee height needs to be increased to 3 feet at/or near the bridge to meet minimum freeboard requirements.

5.4 Closures

Access to the levee closures (sluice gates) that are too low to be operated in floods will be raised to be above the 100-year flood elevations. The levee closures are explained in more detail in Section 8.

5.5 Embankment Protection

The proposed levee is designed to be protected with at least 2 feet of non-dispersive clay cap. The installation of the new non-dispersive clay, topsoil, and vegetative cover is anticipated to protect the levee from erosion due to the floodwaters acting against the levee for short periods of time.

In addition, to evaluate the erosion, the estimated channel velocities for the 100-year flood were compared with published values of permissible velocities. Based on the USACE Engineer Manual (EM) 1110-2-1601 (USACE 1994), the maximum mean channel velocities on clay are 6.0 fps and on grass-covered clay are 8 fps. Channel velocities in the Rio Grande channel along the levees range from 2.89 fps to 9.64 fps.

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Channel velocities over 9 fps are expected at the bridge locations. Borderland Bridge and Country Club Bridge abutments are covered with concrete slope paving. Racetrack Bridge and Sunland Park Bridge abutments are covered with wire encased stone riprap. As a result, no significant hydraulic impact should exist at the bridge location.

Channel velocities of slightly higher than 6 fps were encountered downstream of Sta. 1696+00 on the West Levee and corresponding levee segment across the river on the East Levee from Sta. 1695+00 to Sta. 1713+00, most likely due to the narrower channel width at that cross section. Riprap will be required on the riverside levee slopes on these levee segments for both West and East Levee.

During rain and flood events, the water may accumulate at the toe. Toe drains were designed at the East Levee toe with riprap every 50 feet to reduce erosion due to water accumulation. Specific details are shown in the contract drawings. The distance of 50 feet is a practical number with the intent to get the water out of the toe so that it does not erode.

For West Levee, due to the limited clearance for construction, the toe drains cannot be extended similarly to East Levee. Therefore, we recommend that the riprap be grouted with flowable fill at the toe to create a less permeable material so that the water daylights. Contract drawings provide more details of this design.

For the remainder of the alignment, results of the H&H analysis indicate that there is no significant hydraulic impact to the levee slopes as the anticipated velocities on the levee slopes are lower than the mean permissible velocities in the channel.

5.6 Embankment and Foundation Stability

5.6.1 Seepage Analysis

The previous design (S&BI 2010) included toe drains on the landside to reduce the seepage exit gradients at the landside toe. The seepage analyses in the previous design assumed a steady-state condition, which implies that the water will stand against the levee long enough to enable development of steady-state seepage conditions. Given the relatively short duration of a flood event, Arcadis is in the opinion that a transient seepage condition should be modeled for the seepage analysis in lieu of the steady-state seepage as there is not sufficient time for steady-state seepage to develop.

The forensic study from Kenall (2016) included steady-state seepage analyses for three cross sections with toe drains on the landside. The exit gradients at CE2 Sta. 1671+70 from Kenall are shown on Figure

4. Arcadis analyzed transient seepage without toe drains at CE2 Sta. 1672+00 using Kenall’s soil properties without toe drains. The resulting exit seepage gradients were less than 0.5, which is the maximum permissible value per USACE requirements. Based on these findings, Arcadis believes that toe drains are not needed on the landside. The results of the seepage analysis without toe drains are shown on Figure 5.

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Figure 4. Steady-State Seepage Results East Levee with Toe Drains (from Kenall 2016)

Figure 5. Exit Gradients at Levee Toe without Toe Drains – Transient Seepage (CE2 Sta. 1672+00)

Additional details for seepage analyses for Sta. 1672+00, 1722+00 and 1826+00 on the East Levee and Sta. 1675+00 on the West Levee are presented in Appendix B.2. For these analyses, we have assumed the subsurface profile and soil properties provided by USIBWC based on historic studies.

Transient Seepage Model: For the long-term condition, we performed transient seepage analysis to determine the pore pressures developed during the 100-year flood. We evaluated the seepage conditions using Geo-Slope software SEEP/W, a finite element program. Seepage evaluations were performed using transient seepage analysis based on the hydrograph extracted from the FLO-2D model provided by USIBWC as shown on Figures 6 and 7. No toe drains were assumed in these seepage models.

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Figure 6. Elevation Hydrograph at CE2 Sta. 1672+00

Figure 7. Flow Hydrograph at CE2 Sta. 1672+00

Unsaturated Characteristics: The saturated permeability values (Table 5) used in the analysis were provided by USIBWC based on historic studies. We selected unsaturated soil characteristics for the materials above the initial groundwater. For the transient unsaturated analysis, the Soil-Water Characteristic Curves (SWCC) (i.e., matric suction versus volumetric water content) of the materials were estimated from the sample functions available in GeoStudio. The values of zero-pressure saturated volumetric content used for the soil layers ranged from 0.38 for sand to 0.5 for clay materials. These values were based on the typical volumetric water contents presented in SEEP/W manual. Given the SWCC and saturated permeability, the unsaturated permeability versus matric suction functions of the

February 2022 arcadis.com materials were predicted based on the equation of Van Genuchten method included in the SEEP/W software.

Table 5. Soil Properties used for Seepage Analysis

Boundary Conditions: We applied two types of boundary conditions for the seepage analysis. For transient seepage analysis, the floodside boundary condition consisted of the 100-year flood event. On the protected side, we applied the seepage face review option for the boundary condition. Seepage face boundary conditions are used when the phreatic surface intersection with the ground surface needs to be determined.

Seepage Analysis Results and Conclusions: In general, a seepage exit gradient of 0.5 or less near the toe of the levee slope (where the exit gradient is defined as the ratio of entry pore pressure divided by the soil weight of an element at the discharge point) is considered acceptable. The allowable exit gradient increases linearly from 0.5 at the landside levee toe.

The transient seepage analyses indicate that significant infiltration of water from flood flows into the river side of the levee embankment is unlikely to result in a steady-state condition. Both cross sections that we analyzed indicated exit gradients of less than 0.5, which is the permissible value.

5.6.2 Slope Stability Analysis

Previous geotechnical studies from Kenall (2016) and S&BI (2008, 2010) indicated that cross sections along the levee were evaluated for seepage and slope stability. Based on our review of these previous geotechnical studies, the slope stability factors of safety were adequate for the proposed work. In this project, minor fills of less than one foot will be added to the levee portions that are being widened to satisfy the 16-foot-wide gravel roadway criteria. Typically, a wider levee means a longer seepage path and an increased stability. Therefore, seepage and slope stability will not be adversely affected by the proposed levee improvements and may be improved where new levees will be wider than the existing levees.

Material Hydraulic

Conductivity (fps)

Vertical to Horizontal Hydraulic

Conductivity Ratio

Clay Blanket 4.9E-08 0.33

Sandy Lean Clay (levee) (1) 4.9E-08 0.33

Sandy Lean Clay (1) 3.0E-08 0.10

Fat Clay (1) 3.0E-08 0.10

Silty Sand (1) 5.0E-05 0.33

Poorly graded Sand (w. silt) (1) 3.0E-04 0.33 Note: (1) Soil properties provided by USIBWC

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Arcadis acknowledges that we have evaluated the slope stability runs included in Kenall’s forensic report based on the soil properties included in Kenall’s report provided by USIBWC. The slope stability factors of safety appear to satisfy the minimum criteria. In addition, Arcadis selected three cross sections on the East Levee and one cross section on the West Levee to be analyzed independently from the previous design. The cross sections selected correspond to Sta. 1672+00, 1722+00 and 1826+00 on the East Levee and Sta. 1675+00 on the West Levee.

Slope stability analyses were evaluated for four loading conditions, or critical cases, per USACE EM 1110-2-1913 “Design and Construction of Levees,” which include:

End of Construction: This analysis is appropriate for levee raises as proposed in our design. Short-term (Undrained) stability analysis applies to the stability evaluation at the end-of-construction. Total stress analysis with undrained shear strength properties is typically used for low-permeability soils, and effective stress analysis with drained shear strength properties is typically used for free-draining soils. Slope stability was checked for both landside and riverside.

Rapid Drawdown: This case assumes that a prolonged flood level drops faster than the soil can drain. The floodside slope may become unstable due to development of excess pore water pressures.

Long-Term Stability (100-year Flood): This condition is critical for the landside of the embankment and applies to stability evaluation for a transient seepage condition. The transient seepage conditions represent a period when the excess pore pressure generated during the design hydrograph has peaked within the levee embankment and foundation. Effective stress analysis with drained shear strength properties is used for free-draining soils, while total stress analysis with undrained shear strength properties is used for low-permeability soils. For the 100-year flood, the pore pressures needed in the slope stability analysis were imported directly from the seepage analysis model.

Seismic (Earthquake) Stability Analysis: This analysis was not performed as historical seismic events have not produced ground motions sufficient to require this analysis.

Slope stability analyses coupled with seepage analyses were performed using the Spencer’s Method (a force and equilibrium method) as programmed into SLOPE/W. Stability of the levee slopes depends on several factors including but not limited to: maximum flood elevation and duration, levee geometry and berms, external loads, seepage paths, levee and foundation materials, soil compaction during construction, penetrations in the levee, and drainage layers. These factors are described in more detail as follows:

Flood: Maximum flood elevation and duration is based on the hydrograph for the 100-year flood extracted from the FLO-2D model as presented on Figure 6. From Figure 6, it can be concluded that, during the 100-year event, the base flood reaches the peak for about 1.5 days (time between peak and when flow reaches the levee) and falls back to the levee toe at about 1.1 days (time between peak and when flow leaves the levee). Due to this short duration, the design hydrograph has not been sufficiently long to establish steady-state seepage.

Geometry: Levee geometry is described in more detail in Section 6.2. We have used levee slopes of 3H:1V for our analysis. Steeper slopes of 2.5H:1V were also analyzed for the cross section at CW2 Sta. 1675+00 as presented in Appendix B.2.

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Geotechnical Loads: A vertical surcharge loading of 250 pounds per square foot was assumed to act on the levee crest to reflect potential area loads from operation and maintenance equipment.

Seepage: We evaluated seepage using transient seepage analysis using the hydrograph presented on Figures 6 and 7. Before the flood, the soils are in a partially saturated condition and the degree of saturation increases as the flood seeps through the levee and the levee foundation layers. Due to the short duration of the flood, the seepage path or the phreatic surface will be lower than a steady-state seepage condition as the soil layers will not have sufficient time to become fully saturated. A lower phreatic surface leads to a higher factor of safety for the levee.

Materials: The subsurface stratigraphy and soil characteristics for the cross sections selected for analysis were obtained from Kenall (2016). The embankment fill material consists of sandy lean clay. The levee foundation consists in general of sandy lean clay and occasionally fat clay. Silty sand and sand underlie the clay soils. The specific stratigraphy included in our analyses is presented in Appendix B.2. For our analyses, we have assumed the soil properties based on historic studies provided from USIBWC (Table 6).

Table 6. Soil Properties used for Sunland Levees Slope Stability Analysis

Compaction:…