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Design Documentation Report Contract No. IBM10T0029 Ysleta to Fabens Task Order IBM09D0008 June 2012

URS Group, Inc. ii USIBWC, El Paso, Texas

STATEMENT OF LIMITATIONS 1

This Document is for USIBWC use only. The scope of services performed within may not be 2 appropriate to satisfy the needs of other users. Any use or re-use of this document or of the 3 findings, conclusions, or recommendations presented herein is the sole risk of the user. 4

June 2012

URS Group, Inc. iii USIBWC, El Paso, Texas

TABLE OF CONTENTS 1

1.0 PROJECT INFORMATION ........................................................................................ 1-9 3

1.1 General ................................................................................................................. 1-9 4

1.2 Authorization ....................................................................................................... 1-9 5

1.3 Purpose of Design Documentation Report ........................................................... 1-9 6

1.4 Project Description ............................................................................................... 1-9 7

1.4.1 Project Location ....................................................................................... 1-9 8

1.4.2 Existing Features ...................................................................................... 1-9 9

1.4.3 Project Objectives .................................................................................. 1-10 10

1.4.4 Project Requirements ............................................................................. 1-10 11

1.4.5 Description of Alterations ...................................................................... 1-12 12

1.5 Project Deliverables ........................................................................................... 1-14 13

2.0 PERTINENT DATA ...................................................................................................... 2-1 14

2.1 Project Purpose .................................................................................................... 2-1 15

2.2 Opinion of Probable Construction Cost ............................................................... 2-1 16

2.3 Existing Utilities .................................................................................................. 2-1 17

2.4 Design Data .......................................................................................................... 2-1 18

2.4.1 Controlling Elevations ............................................................................. 2-1 19

2.4.2 Hydraulics Data ........................................................................................ 2-1 20

2.4.3 Survey Data .............................................................................................. 2-1 21

2.4.4 Soil Borings .............................................................................................. 2-2 22

3.0 DESIGN INFORMATION AND REFERENCES ...................................................... 3-1 23

3.1 Design Criteria ..................................................................................................... 3-1 24

3.2 Other Codes and Standards Used in Design ........................................................ 3-3 25

3.3 General References .............................................................................................. 3-4 26

3.4 Approval Criteria Waivers ................................................................................... 3-4 27

3.5 Computer Programs Used .................................................................................... 3-5 28

3.6 Government-Provided Information ...................................................................... 3-6 29

4.0 ENGINEERING DESIGN ............................................................................................ 4-1 30

4.1 Hydrology and Hydraulics ................................................................................... 4-1 31

4.1.1 Background .............................................................................................. 4-1 32

4.1.2 Hydraulic Features ................................................................................... 4-1 33

4.1.3 Drainage Structures .................................................................................. 4-1 34

4.2 Geotechnical ......................................................................................................... 4-2 35

4.2.1 Objectives ................................................................................................. 4-2 36

4.2.2 Background .............................................................................................. 4-2 37

4.2.3 Nearby Structures ..................................................................................... 4-4 38

4.3 Project Setting ...................................................................................................... 4-6 39

4.3.1 Regional Geology .................................................................................... 4-6 40

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URS Group, Inc. iv USIBWC, El Paso, Texas

4.3.2 Site Seismicity .......................................................................................... 4-6 1

4.3.3 Geomorphology ....................................................................................... 4-7 2

4.4 Geotechnical Drilling ........................................................................................... 4-7 3

4.5 Geotechnical Laboratory Testing ......................................................................... 4-8 4

4.6 Evaluation Methodology ...................................................................................... 4-8 5

4.6.1 Subreach 1 – Riverside Dam to Wasteway No. 1 (Sta. 805+37.81 to 6 933+30) .................................................................................................... 4-9 7

4.6.2 Subreach 2 – Wasteway No. 1 to Wasteway No. 2 (Sta. 933+30 to 8 1319+23) .................................................................................................. 4-9 9

4.6.3 Subreach 3 – Wasteway No. 2 to Fabens (Sta. 1319+23 to 10 1633+49.80) ........................................................................................... 4-10 11

4.7 Summary of Analyses Performed ...................................................................... 4-10 12

4.8 Analysis Results ................................................................................................. 4-11 13

4.8.1 Seepage and Slope Stability ................................................................... 4-11 14

4.8.2 Liquefaction ........................................................................................... 4-13 15

4.8.3 Settlement ............................................................................................... 4-14 16

4.8.4 Erosion Control ...................................................................................... 4-14 17

4.9 Geotechnical Design Features ............................................................................ 4-15 18

4.9.1 Seepage Control Measures ..................................................................... 4-15 19

4.9.2 Slope Stabilization Measures ................................................................. 4-16 20

4.9.3 Operations and Maintenance (O&M) Program ...................................... 4-16 21

4.10 Environmental Considerations ........................................................................... 4-17 22

4.10.1 Overview ................................................................................................ 4-17 23

4.10.2 Biological Resources .............................................................................. 4-18 24

4.10.3 Cultural Resources ................................................................................. 4-18 25

4.10.4 Construction Approaches ....................................................................... 4-19 26

4.11 Structural Design Features ................................................................................. 4-19 27

4.11.1 Overview ................................................................................................ 4-19 28

4.11.2 Load Conditions ..................................................................................... 4-19 29

4.11.3 Structural Design of Drainage Structures .............................................. 4-20 30

4.11.4 Retaining Wall Design ........................................................................... 4-22 31

4.12 Loads .................................................................................................................. 4-23 32

4.12.1 General Loading ..................................................................................... 4-23 33

4.12.2 Sliding and Overturning ......................................................................... 4-24 34

4.13 Concrete Design Criteria .................................................................................... 4-26 35

4.13.1 Strength Reduction and Load Factors .................................................... 4-26 36

4.13.2 Reinforcing Steel .................................................................................... 4-26 37

4.14 Steel Design Criteria .......................................................................................... 4-26 38

4.15 Civil Design Features ......................................................................................... 4-27 39

4.15.1 Excavation of Existing Levee ................................................................ 4-27 40

4.15.2 Typical New Levee Section ................................................................... 4-27 41

4.15.3 Surface Drainage .................................................................................... 4-27 42

4.15.4 Interim Flood Protection ........................................................................ 4-27 43

4.15.5 Roadways ............................................................................................... 4-27 44

4.15.6 Utility Relocation ................................................................................... 4-27 45

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URS Group, Inc. v USIBWC, El Paso, Texas

4.15.7 Traffic Plan ............................................................................................ 4-27 1

4.16 Construction Plan ............................................................................................... 4-27 2

4.16.1 Sequence of Construction ...................................................................... 4-28 3

4.17 Real Estate Information ..................................................................................... 4-29 4

4.17.1 New Levee Right-of-Way ...................................................................... 4-29 5

4.17.2 Construction Laydown/Staging Area ..................................................... 4-29 6

4.18 Government-Furnished Borrow Material Location ........................................... 4-29 7

4.19 Haul Route ......................................................................................................... 4-29 8

4.20 Access Roads ..................................................................................................... 4-29 9

4.21 Utility Removal .................................................................................................. 4-29 10

4.22 Dewatering Plan (if applicable) ......................................................................... 4-30 11

4.23 Storm Water Pollution Prevention Plan (SWPPP) ............................................. 4-30 12

5.0 PROJECT COST ESTIMATE ..................................................................................... 5-1 13

5.1 Overview .............................................................................................................. 5-1 14

5.2 Assumptions ......................................................................................................... 5-1 15

5.3 Cost Estimate Narrative ....................................................................................... 5-2 16

5.3.1 Scope of Work ......................................................................................... 5-2 17

5.3.2 Risk Analysis ........................................................................................... 5-2 18

5.3.3 Escalation ................................................................................................. 5-2 19

5.3.4 Forward Pricing ........................................................................................ 5-2 20

6.0 CONSTRUCTION SCHEDULE .................................................................................. 6-1 21

6.1 Overview .............................................................................................................. 6-1 22

6.2 Schedule Constraints ............................................................................................ 6-1 23

6.3 Assumptions for the Construction Schedule ........................................................ 6-1 24

6.3.1 Rain Days ................................................................................................. 6-2 25

6.4 Description of Critical Path Items ........................................................................ 6-2 26

6.5 Potential Delays for Construction ........................................................................ 6-2 27

6.5.1 Environmental Issues ............................................................................... 6-2 28

7.0 ADDITIONAL INFORMATION REQUIRED .......................................................... 7-1 29

8.0 OPERATIONS AND MAINTENANCE ...................................................................... 8-1 30

June 2012

URS Group, Inc. vi USIBWC, El Paso, Texas

LIST OF TABLES 1

1-1 Summary of Ysleta to Fabens Levee Reach Structures and Utilities 2 1-2 Areas of Existing Levee Crest Less than 16 Feet 3 1-3 Milestones 4 4-1 Drainage Structures 5 4-2 Summary of USACE Condition Assessment 6 4-3 Geotechnical Laboratory Tests 7 4-4 Summary of Computed Factors of Safety for Subreach 1 8 4-5 Summary of Exit Seepage Gradients for Subreach 1 9 4-6 Summary of Computed Factors of Safety for Subreach 2 10 4-7 Summary of Exit Seepage Gradients for Subreach 2 11 4-8 Summary of Computed Factors of Safety for Subreach 3 12 4-9 Summary of Exit Seepage Gradients for Subreach 3 13 4-10 Analysis of Velocity and Shear Stress Conditions 14 4-11 Load Conditions for Drainage Structure Design 15 4-12 Unit Weights 16 4-13 Load Conditions for Retaining Wall Design 17 6-1 Monthly Anticipated Adverse Weather Delay Work Days Based on 5-Day Work 18

Week and 0.5-Inch Rain Event 19

FIGURES 21

1 Project Location and Vicinity Map 22 2 Geologic Map of Project Area 23 3 Levee Alignment Borings Plan and Profile Sheet 1 of 9 24 4 Levee Alignment Borings Plan and Profile Sheet 2 of 9 25 5 Levee Alignment Borings Plan and Profile Sheet 3 of 9 26 6 Levee Alignment Borings Plan and Profile Sheet 4 of 9 27 7 Levee Alignment Borings Plan and Profile Sheet 5 of 9 28 8 Levee Alignment Borings Plan and Profile Sheet 6 of 9 29 9 Levee Alignment Borings Plan and Profile Sheet 7 of 9 30 10 Levee Alignment Borings Plan and Profile Sheet 8 of 9 31 11 Levee Alignment Borings Plan and Profile Sheet 9 of 9 32 12 Geotechnical Evaluation of Levee Alignment for Subreach 1 33 13 Geotechnical Evaluation of Levee Alignment for Subreach 2 34 14 Geotechnical Evaluation of Levee Alignment for Subreach 3 35 15 Supplemental Borings Levee Cross-Section Sheet 1 of 6 36 16 Supplemental Borings Levee Cross-Section Sheet 2 of 6 37 17 Supplemental Borings Levee Cross-Section Sheet 3 of 6 38 18 Supplemental Borings Levee Cross-Section Sheet 4 of 6 39 19 Supplemental Borings Levee Cross-Section Sheet 5 of 6 40 20 Supplemental Borings Levee Cross-Section Sheet 6 of 6 41

June 2012

URS Group, Inc. vii USIBWC, El Paso, Texas

APPENDICES 1

A Plans 2 B Geotechnical Analysis and Engineering Evaluation (Geotechnical Report) and 3

Supplemental Geotechnical Analysis (Geotechnical Supplement) Submitted by RKCI 4 C Final Cost Estimate 5 D Final Construction Schedule 6 E Operations and Maintenance Manual 7 F Engineering Considerations and Instructions 8

Acronyms and Abbreviations 11

ACI American Concrete Institute 12

APE Area of Potential Effect 13

ASTM ASTM International 14

CDC Corridor Development Certificate 15 cfs cubic feet per second 16

CWE Current Work Estimate 17

DDR Design Documentation Report 18

DHS Department of Homeland Security 19

DPE Design Protection Elevation 20

DPF Design Project Flood 21

EA Environmental Assessment 22

ENR Engineering News-Record 23

EOF Engineering Office Files 24

EPCWID1 El Paso County Water Improvement District #1 25

FEMA Federal Emergency Management Administration 26 fps feet per second 27

HEC-RAS Hydrologic Engineering Center River Analysis System 28

IBC International Building Code 29

JOOH Job Office Overhead 30

MOV motor operated valve 31

NPDES National Pollutant Discharge Elimination System 32

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URS Group, Inc. viii USIBWC, El Paso, Texas

NRHP National Registry of Historic Places 1

OMRRR Operation, Maintenance, Repair, Replacement, and Rehabilitation Manual 2

PDF Portable Document Format 3

QTO Quantity Takeoff 4

RGRP Rio Grande Rectification Project 5

RKCI Raba-Kistner Consultants, Inc. 6

ROW right-of-way 7

SHPO Texas State Historical Preservation Office 8

SOW Scope of Work 9

SWPPP Stormwater Pollution Prevention Plan 10

THC Texas Historical Commission 11

TOLE Tope of Levee Elevation 12

TPWD Texas Parks and Wildlife Department 13

TxDOT Texas Department of Transportation 14

URS URS Group, Inc. 15

USACE U.S. Army Corps of Engineers 16

USIBWC United States International Boundary and Water Commission 17

WBS Work Breakdown Structure 18

WSE Water Surface Elevation 19

June 2012

URS Group, Inc. 1-9 USIBWC, El Paso, Texas

1.0 PROJECT INFORMATION 1

1.1 General 2

The portion of the Rio Grande Rectification Project (RGRP) located in El Paso and Hudspeth 3 Counties, Texas from Ysleta to Fabens was constructed from 1934 to 1938. The purpose of the 4 project was to stabilize the international river boundary and provide flood protection for both 5 counties in urban, suburban, and agricultural areas. The RGRP also provides irrigation and 6 drainage benefits to agricultural areas. The U.S. International Boundary and Water Commission 7 (USIBWC) investigated the structural condition of the levee from Ysleta to Fabens based on a 8 100-year flood event. This reach represents approximately 15.8 miles of the 91 levee miles in 9 the RGRP on the United States side. The work required under this Scope of Work (SOW) will 10 be limited to this 15.8-mile reach. 11

1.2 Authorization 12

Funds were allocated to the USIBWC as part of the American Recovery and Reinvestment Act 13 (ARRA) of 2009 for the rehabilitation of the RGRP, which includes the Ysleta to Fabens levee. 14 The USIBWC retained the services of URS Group, Inc. (URS) under Task Order IBM10T0029 15 of Contract No. IBM09D0008 to provide services for the design and preparation of the plans and 16 specifications for the improvements project. The SOW entitled "Scope of Work for Design of 17 Rehabilitation Improvements, Riverside Dam to Fabens within El Paso County, Texas," dated 18 September 2010, was provided to URS by the USIBWC. 19

1.3 Purpose of Design Documentation Report 20

This Design Documentation Report (DDR) presents the basis for design and the essential data, 21 assumptions, criteria, and computations for developing the design, plans, specifications, and 22 costs for improvements to the Ysleta to Fabens Reach. The purpose of the DDR is to provide 23 sufficient design detail and analyses to support the preparation and review of the deliverables for 24 this project. 25

1.4 Project Description 26

1.4.1 Project Location 27

The Ysleta to Fabens Reach of the USIBWC levee is located within El Paso County in Texas, as 28 shown on the project location map in Figure 1. The levee reach is approximately 15.8 miles 29 long. For analysis purposes, the reach was divided into three subreaches: Subreach 1, Subreach 30 2, and Subreach 3. 31

1.4.2 Existing Features 32

The existing Ysleta to Fabens Reach consists of an earthen embankment constructed of silts, 33 sands, and clays with an approximate crown width of 11 to 16 feet and an average height of 7.2 34 feet. 35

June 2012

URS Group, Inc. 1-10 USIBWC, El Paso, Texas

Figures 3 through 11 illustrate some of the features located along the levee. The "Final 1 Environmental Assessment Improvements to the Rio Grande Rectification Project," March 2009, 2 identified three structures located within the boundaries of the Ysleta to Fabens levee 3 improvement project. The structures crossing the levee section are described in Table 1-1. Also 4 included for reference are five bridges that provide Department of Homeland Security 5 (DHS)/Border Patrol access which do not cross the levee section but are in the vicinity of the 6 project. 7

1.4.3 Project Objectives 8

The objectives for the Ysleta to Fabens levee rehabilitation improvement project include: 9

• Conducting geotechnical investigations and testing to determine the type and extent 10 of required remediation improvements due to slope instability, seepage, levee 11 settlement, and erosion. 12

• Assessing existing structures within the levee reach and rehabilitating structures as 13 necessary. The design must allow for closure of structures during flood events and 14 must encompass necessary structural repair or replacement. 15

• Certifying the levee to withstand the 100-year flood with +3 feet of freeboard. 16

1.4.4 Project Requirements 17

The following are requirements for the Ysleta to Fabens levee improvements, per the SOW: 18

• Follow U.S. Army Corps of Engineers (USACE) and Federal Emergency 19 Management Administration (FEMA) criteria for flood risk reduction design (See 20 Section 3). 21

• Design a minimum 16-foot-wide maintenance road at the crest of the levee consisting 22 of a 6-inch layer of flex-base material directly placed on the finished embankment 23 material. 24

• Design sideslopes to be no steeper than 3H:1V on the river side and no steeper than 25 3H:1V on the land side. However, if existing right-of-way (ROW) is insufficient, 26 then land-side sideslopes cannot be steeper than 2.5H:1V unless the design does not 27 require mowing. 28

• Ensure that construction activities do not disturb existing wetlands or cemeteries. 29

• Evaluate existing levee conditions and past levee performance 30

June 2012

URS Group, Inc. 1-11 USIBWC, El Paso, Texas

Table 1-1 Summary of Ysleta to Fabens Levee Reach Structures and Utilities 1

Structure Station

Structure Elevation (ft msl)

Utility Flow Line

Coordinates Structure

Name Structure Size Structure Usage Ownership Notes X

(Easting) Y

(Northing) 933+30 Top of

Levee:

3663.29*

3649.8 438302.34 10606233.55 Wasteway No. 1

Five sluice gates with five 6-ft x 5-ft box culverts

Drainage/Irrigation EPCWID #1

956+08 3660 3642 439258.858 10604156.95 Lower Valley Interceptor

Wastewater interceptor outfall Wastewater Interceptor Outfall

EPWU Wastewater interceptor outfall daylighting at the Rio Grande.

958+91.96 3660.89 439489.27 10606461.23 Doubles Bridge

A 13 ft-10 inch wide bridge that spans the Riverside Canal for 68 ft. A second bridge with a width of13 ft 10 inches that spans 40 ft over the Riverside intercepting drain.

Emergency Access DHS / Customs and Border Protection

Proposed bridge was not constructed at the time the DDR was prepared. This structure is not on the Rio Grande and is not in the USIBWC ROW.

1012+10.09 3657.15 439813.75 10601243.30 Walcott Bridge

A 13 ft-10 inch wide bridge that spans the Riverside Canal for 65 ft. A second bridge with a width of13 ft 10 inches that spans 37 ft over the Riverside intercepting drain.

Emergency Access DHS / Customs and Border Protection

Proposed bridge was not constructed at the time the DDR was prepared. This structure is not on the Rio Grande and is not in the USIBWC ROW.

1055+93.00 3654.78* 442061.93 10595100.28 Irrigation gates / check dam

Eight irrigation gates / check dam Drainage/Irrigation EPCWID #1

1068+50.00 3652.26* 442136.52 10593836.96 Irrigation gates / check dam

Eight irrigation gates / check dam Drainage/Irrigation EPCWID #1

1198+57.63 3642.91 445615.27 10583925.87 Las Pompas Bridge

A 26 ft-2 inch wide bridge that spans the Riverside Canal for 72 ft.

Emergency Access DHS / Customs and Border Protection

Proposed bridge was not constructed at the time the DDR was prepared. This structure is not on the Rio Grande and is not in the USIBWC ROW.

1266+05.97 3640.34 451151.53 10580072.21 Herring Bridge

A 13 ft-10 inch wide bridge that spans the Riverside Canal for 67 ft. A second bridge with a width of13 ft 10 inches that spans 40 ft over the Riverside intercepting drain.

Emergency Access DHS / Customs and Border Protection

Proposed bridge was not constructed at the time the DDR was prepared. This structure is not on the Rio Grande and is not in the USIBWC ROW.

1266+57.00 Top of Levee:

3639.26*

3610 451079.42 10577482.53 Oil line 8-inch-diameter oil line in casing Oil Line Crossing Enterprise Products Remote Motor-Operated Valve (MOV) can be operated from the field, Houston, or by pressure sensor. MOV location 500 ft NE of the intersection of Riverside Drive and Herring Rd.

1266+67.00 Top of Levee:

3639.26*

3610 451087.87 10577476.82 Oil line 10-inch-diameter oil line in casing Oil Line Crossing Buckeye Pipeline Company

MOV can be operated from the field, Houston, or by pressure sensor. MOV location 600 ft SE of the intersection of Riverside Drive and Herring Rd.

1299+05.00 Top of Levee:

3636.95*

3606 453682.95 10575550.12 Natural gas line

24-inch-diameter natural gas pipe line Natural Gas Crossing El Paso Natural Gas Company

Manual Operated Valve: location TBD; within a few miles NE of the levee/utility intersection.

1319+12.00 Top of Levee:

3633.05*

3625.02 455147.81 10574171.16 Wasteway No. 2

Three sluice gates with three 6-ft x 5-ft box culverts

Drainage/Irrigation EPCWID #1

1602+13.52 3612.99 464764.49 10550730.26 Jess Harris Bridge

A 13 ft-10 inch wide bridge that spans the border drain for 47 ft.

Emergency Access DHS / Customs and Border Protection

Proposed bridge was not constructed at the time the DDR was prepared. This structure is not on the Rio Grande and is not in the USIBWC ROW.

* Estimated elevations from as-built plans. 2

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URS Group, Inc. 1-12 USIBWC, El Paso, Texas

• Conduct a geotechnical investigation of levee embankment materials and foundation 1 soils and perform seepage and stability analyses to assess levee performance during 2 the design flood event and other critical hydraulic cases. 3

• Minimum Top of Levee Elevation (TOLE). 4

• Evaluate and compare existing conditions with USACE guidelines. 5

• Evaluate erosion potential on the levee slope. 6

• Determine the type and extent of rehabilitation, if required. 7

• Develop O&M recommendations. 8

1.4.5 Description of Alterations 9

The alterations for the Ysleta to Fabens levee improvements include: 10

• Structures: 11 o Wasteway 1 box culvert replacement – Replace five existing 6-ft x 5-ft box 12 culverts with five new 6-ft x 5-ft box culverts. 13 o Wasteway 2 box culvert replacement – Replace three existing 6-ft x 5-ft box 14 culverts with three new 6-ft x 5-ft box culverts and new slide gates. 15 o Remove the wastewater effluent manhole and grout discharge line. 16

• Levee crest widening: 17 o Widen the levee crest to 16 feet in width at the following sections: 18

Table 1-2. Areas of Existing Levee Crest Less than 16 Feet 19

Starting Station Ending Station Length (ft) Existing Levee Width (min., ft)

917+00 919+60 270 15.7 919+70 937+90 1820 11.1 939+85 947+80 795 13.4 950+15 955+00 335 14.9 961+00 966+40 295 14.9 967+20 968+50 130 15.2 969+85 972+40 255 15.2 972+40 976+30 390 14.2 976+60 984+00 280 15.0

June 2012

URS Group, Inc. 1-13 USIBWC, El Paso, Texas

Starting Station Ending Station Length (ft) Existing Levee Width (min., ft)

1035+00 1044+00 780 13.6 1052+00 1053+90 135 15.0 1056+50 1059+00 210 14.2 1075+00 1086+00 1000 14.6 1170+00 1182+20 1205 14.1 1184+25 1192+50 825 14.3 1194+25 1197+40 315 12.1 1198+90 1203+95 505 14.2 1207+30 1220+00 935 12.6 1226+00 1230+00 155 14.3 1240+00 1251+45 860 14.5 1252+40 1259+00 545 14.8 1283+00 1291+00 635 13.2 1307+00 1313+90 560 13.9 1318+10 1342+75 2465 11.8 1345+00 1348+35 335 15.2 1351+25 1353+00 115 15.2 1473+00 1486+00 1260 12.8 1491+00 1505+00 830 13.7 1512+00 1527+70 1495 13.0 1537+00 1528+00 195 15.3 1539+40 1550+00 1010 15.0 1572+00 1575+55 390 14.7 1577+90 1587+35 945 14.5 1589+05 1592+20 315 15.2 1592+90 1596+70 380 15.8 1599+35 1607+00 725 14.3 1610+00 1617+15 635 15.4 1619+55 1628+00 315 15.5 1633+00 1637+00 270 14.6 1641+00 1648+00 275 15.1

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URS Group, Inc. 1-14 USIBWC, El Paso, Texas

1.5 Project Deliverables 1

Table 1-3. Milestones 2

Deliverable Due Date for Submittal 60% Construction Drawings 14 May 2011 90% Construction Drawings, Specifications, Opinion of Probable Cost, Design Documentation Report 31 August 2011

Final Construction Drawings 11 October 2011

(Original) July 2012 (Delayed)

June 2012

URS Group, Inc. 2-1 USIBWC, El Paso, Texas

2.0 PERTINENT DATA 1

2.1 Project Purpose 2

The purpose of this project is to review and recommend rehabilitation needs and maintenance 3 operations for the existing flood protection to contain the DPF+3. The project will include the 4 evaluation and replacement of deteriorated structures, a geotechnical evaluation of the levee 5 system, and recommendations for future operations and maintenance (O&M) procedures. 6

2.2 Opinion of Probable Construction Cost 7

In Section 5 and Appendix C. 8

2.3 Existing Utilities 9

The existing utilities along the Ysleta to Fabens Reach include oil pipeline crossings and natural 10 gas pipeline crossings. These utilities have all been located using field verification and historical 11 documentation and by contacting known utilities in the area to verify the location of their 12 utilities. A complete list of all known utilities and their respective locations within the project 13 limits and elevations of crossing is provided in Table 1-1. 14

2.4 Design Data 15

2.4.1 Controlling Elevations 16

The controlling elevation is the minimum Top of Levee Elevation (TOLE), which is equal to the 17 100-year water surface elevation (WSE) plus 3 feet of freeboard. 18

2.4.2 Hydraulics Data 19

The following hydraulics data were provided by the USIBWC: 20

• Excel® spreadsheet with 100-year WSE and minimum TOLE for the Riverside Dam 21 to Fabens Reach; and 22

• Hydrologic Engineering Center River Analysis System (HEC-RAS) Model for the 23 Riverside Dams to Fabens Reach. 24

2.4.3 Survey Data 25

Existing topographic data shown on the plans was produced from an on-the-ground survey 26 performed by Frank X. Spencer & Associates, Inc., El Paso, TX during October/November 2010. 27 An additional topographic survey was conducted for the canal and submitted in June 2011. The 28 horizontal coordinates shown on the plans are referenced to the Texas State Plan Coordinate 29 System, Central Zone, NAD83, U.S. Survey feet. Coordinates shown are surface coordinates, 30 using a combined scale factor of 1.0002414337. To convert to grid coordinates, multiply by 31

0.99758625 for this project. Surface elevations shown on the plans are referenced to NAVD88. 32

June 2012

URS Group, Inc. 2-2 USIBWC, El Paso, Texas

2.4.4 Soil Borings 1

Soil borings were provided by Raba-Kistner Consultants, Inc. (RKCI) as part of the 2 "Geotechnical Analysis and Engineering Evaluation Report" dated November 2010 3 (Geotechnical Report). Additional soil borings were provided by RKCI as part of the 4 "Supplemental Geotechnical Analysis for Final Design" dated June 2012 (Geotechnical 5 Supplement). RKCI drilled all borings for the project. 6

The original 2010 subsurface investigation included a total of 86 borings, designated as B-1 7 through B-86 and spaced at approximately 1,000-foot intervals. All borings were drilled at the 8 crest of the existing levee. The borings were generally drilled to a depth of 50 feet. Nine 9 borings were drilled to a depth of 100 feet to obtain deeper stratigraphy information. Borings 10 were advanced using a modified hollow-stem auger procedure. Hollow-stem augers were used 11 from the ground surface until caving soils below the groundwater table were encountered. Mud 12 rotary methods were then employed until reaching the boring termination depth. Upon 13 completion of drilling, bentonite-cement grout was used to backfill the boreholes using tremie 14 methods in accordance with USACE guidelines. 15

The supplemental subsurface investigation included an additional 16 borings located at six 16 critical levee cross-sections. These borings were designated as B-101 through B-116 (note that 17 the Geotechnical Supplement presents these borings as B-1 through B-16). Borings were drilled 18 in a line perpendicular to the levee alignment to assess the continuity of subsurface stratigraphy, 19 to calibrate the preliminary analysis model, and to validate assumptions. Series of three borings 20 each were drilled at Stations 863+00, 1089+55, 1529+00, and 1607+00. Each series consisted of 21 one boring near the riverside toe of the levee, one near the landside toe of the levee, and one near 22 the landside bank of the drain or canal. The levee borings were drilled to a depth of 30 feet 23 below existing grade. The same methods used to advance and backfill the borings in the original 24 subsurface investigation were employed for the supplemental investigation; the exception is that 25 all of the borings (six total) at Stations 1529+00 and 1607+00 were converted to piezometers for 26 long-term monitoring of groundwater levels across the levee cross-section. Detailed as-built 27 information for the piezometers is included in the Geotechnical Supplement. In addition, series 28 of two borings each were drilled at Wasteway 1 (Sta. 933+13) and Wasteway 2 (Sta. 1319+23), 29 consisting of one boring on the existing levee crest and one boring on the landside bank of the 30 canal. The wasteway borings were drilled to a depth of 50 feet below existing grade. 31

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URS Group, Inc. 3-1 USIBWC, El Paso, Texas

3.0 DESIGN INFORMATION AND REFERENCES 1

3.1 Design Criteria 2

The following standard is a requirement from the USIBWC for the design of the project: 3

• A/E/C CADD Standard, Release 4.0, July 2009. 4

The following design criteria are part of the USACE requirements for the design of the project: 5

• EC 1110-2-1806, "Earthquake Design and Evaluation for Civil Works." July 31, 6 1995. 7

• EC 1110-2-1901, "Seepage Analysis and Control for Dams." April, 30 1993. 8

• EC 1110-2-1913, "Design and Construction of Levees." April, 30 2000. 9

• EC 1110-2-6067, "Process for the National Flood Insurance Program (NFIP) Levee 10 System Evaluation." August, 31 2010. 11

• EM 1110-1-1002, "Survey Markers and Monumentation," 14 September 1990. 12

• EM 1110-1-1005, "Control and Topographic Mapping," 31 August 1994. 13

• EM 1110-1-1804, "Geotechnical Investigations," 29 February 1984. 14

• EM 1110-1-1904, "Settlement Analysis," 30 September 1990. 15

• EM 1110-1-1905, "Bearing Capacity of Soils," 30 October 1992. 16

• EM 1110-1-1906, "Soil Sampling," 30 September 1996. 17

• EM 200-1-3, "Requirements for the Preparation of Sampling and Analysis Plans," 1 18 February 2001. 19

• EM 1110-2-301, "Guidelines for Landscaping Planting at Floodwalls, Levees, and 20 Embankment Dams," 1 January 2000. 21

• ER 1110-2-1003, "Hydrographic Surveying," 1 January 2002. 22

• ER 1110-2-1200, "Plans and Specifications for Civil Works Projects," 12 June 1972. 23

• EM 1110-2-1205, "Environmental Engineering and Local Flood Control Channels," 24 15 November 1989. 25

• EM 1110-2-1601, "Hydraulic Design of Flood Control Channels," 1 July 1991. 26

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• EM 1110-2-1902, "Slope Stability," 31 October 2003. 1

• EM 1110-2-1908, "Instrumentation of Embankment Dams and Levees," 30 June 2 1995. 3

• EM 1110-2-1911, "Construction Control for Earth and Rock-Fill Dams," 30 4 September 1995. 5

• EM 1110-2-2000, "Standard Practice for Concrete for Civil Works Structures," 1 6 February 1994. 7

• EM 1110-2-2007, "Structural Design of Concrete Lined Flood Control Channels," 30 8 April 1995. 9

• EM 1110-2-2104, "Strength Design for Reinforced Concrete Hydraulic Structures," 10 30 June 1992. 11

• EM 1110-2-2105, "Design of Hydraulic Steel Structures," 31 March 1993. 12

• EM 1110-2-2302, "Construction with Large Stone," 24 October 1990. 13

• EM 1110-2-2902, "Conduits, Culverts, and Pipes," 31 October 1997. 14

• R 1110-1-261, "Quality Assurance of Laboratory Testing Procedures," 28 April 1999. 15

• ER 1110-1-1807, "Procedures for Drilling in Earth Embankments," 30 July 1990. 16

• ER 1110-1-8100, "Laboratory Investigations and Testing," 31 December 1997. 17

• ER 1110-1-8155, "Specifications," 10 October 2003. 18

• ER 1110-2-401, "Operation, Maintenance, Repair, Replacement, and Rehabilitation 19 Manual for Projects and Separable Elements Managed by Project Sponsors," 30 20 September 1994. 21

• ER 1110-2-1150, "Engineering and Design for Civil Works Projects," 31 August 22 1999. 23

• ER 1110-2-8152, "Planning and Design of Temporary Cofferdams & Braced 24 Excavations," 31 August 1994. 25

• ETL 1110-2-256, "Sliding Stability for Concrete Structures," 24 June 1981. 26

• ETL 1110-2-307, "Floatation Stability Criteria for Concrete Hydraulic Structures," 20 27 August 1987. 28

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• ETL 1110-2-569, "Design Guidance for Levee Underseepage," 1 May 2005. 1

• ETL 1110-2-571, "Guidelines for Landscape Planting and Vegetation Management at 2 Levees, Floodwalls, Embankment Dams, and Appurtenant Structures," 10 April 2009. 3

• ETL 1110-2-573, "Construction Cost Estimating Guide for Civil Works," 30 4 September 2008. 5

• SWD-AEIM Architectural and Engineering Instructions Manual. 6

• SWFP 1150-2-1, "Criteria for Construction within the Limits of the Existing Federal 7 Flood Protection Projects," 31 October 2003. 8

• TM 5-818-8, "Engineering Use of Geotextiles," 20 July 1995. 9

• USACE, "Engineering Manual File Format Specification Version: EM06," 7 May 10 2009. 11

3.2 Other Codes and Standards Used in Design 12

The following codes and standards were utilized in completing the design of the Project: 13

• EPA SW-846 Method 6010B/7471A, "Test Methods for Evaluating Solid Waste, 14 Physical/Chemical Methods." 15

• EPA Method 8150B, "Chlorinated Herbicides by Gas Chromatography." 16

• American Association of State Highway and Transportation Officials (AASHTO), 17 Standard Specifications for Highway Bridges. 18

• American Concrete Institute (ACI), Building Code Requirements for Structural 19 Concrete, ACI 318-99. 20

• American Society of Civil Engineers/Structural Engineering Institute Standard 7-05. 21

• ASTM International Standards. 22

• Bureau of Economic Geology at the University of Texas at Austin, "Geologic Atlas 23 of Texas," Van-Horn/El Paso Sheet, 1968. 24

• Texas Commission on Environmental Quality (TCEQ) Protective Concentration 25 Levels (PCLs). 26

• Texas Department of Transportation (TxDOT), Roadway Design Manual, 2004. 27

• TxDOT Specifications and Standards. 28

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URS Group, Inc. 3-4 USIBWC, El Paso, Texas

• Web Soil Survey of El Paso County, U.S. Department of Agriculture, Natural 1 Resources of Conservation Service, 2 http://websoilsurvey.nrcs.usda.gov/app/WebSoilSurvey.aspx. 3

3.3 General References 4

The following documents were reviewed during the design of the Project: 5

• Mapping Alliance Partnership (MAPVI). "Flood Frequency Determination, El Paso 6 County and Incorporated Communities, Texas – Disaster Response Flood Recovery 7 Data." Submitted to U.S. Dept. of Homeland Security, FEMA. March 26, 2007. 8

• RKCI. "DRAFT – Feasibility Study and Conceptual Design for Paisano Reach 9 (Phase II) Upper Rio Grande Flood Control System Rectification Project, El Paso, El 10 Paso County, Texas. Draft Geotechnical Memorandum." Prepared for URS, 11 February 12, 2011. 12

• RKCI. "Geotechnical Analysis and Engineering Evaluation of Rectification Project 13 Levee from Riverside Dam to Fabens, El Paso County, TX." Prepared for URS, 14 November 2010. 15

• RKCI. " Supplemental Geotechnical Analysis for Final Design Rectification Project 16 Levee From Riverside Dam to Fabens, El Paso County, TX." Prepared for URS, 17 December 2011. 18

• RKCI. "Geotechnical Memorandum for Courchesne Reach, El Paso, El Paso County, 19 Texas; Nemexas Reach, Sunland Park, Dona Ana County, New Mexico; Upper Rio 20 Grande Flood Control System Rectification Project." March 2, 2011. 21

• Terracon. "Geotechnical Engineering Report – IBWC Upper Rio Grande Levee 22 Evaluation: Fabens, Texas." December 21, 2009. 23

• URS. "DRAFT – Guidance Document for Geotechnical Analyses." Prepared for 24 Sacramento, CA Department of Water Resources, Urban Levee Geotechnical 25 Evaluations Program Contract. Revision 9, January, 2011. 26

• USACE. ERDC TR-03-4 Report 2: "Condition Assessment of U.S. International 27 Boundary and Water Commission, Texas and New Mexico Levees. Volume III: 28 Rectification Levees." March 2004. 29

3.4 Approval Criteria Waivers 30

No waivers on criteria have been submitted for approval. 31

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URS Group, Inc. 3-5 USIBWC, El Paso, Texas

3.5 Computer Programs Used 1

The following are the computer programs used in development of the Project: 2

• Adobe Portable Document Format (PDF) Writer and Reader; Adobe Professional 3 (Versions 9.0 and 10.0); Adobe Systems Inc. 4

• AutoCAD Civil 3D (2009): Computer-aided drafting and design (CADD) software, 5 AutoDesk, Inc. 6

• Culvert Master: Culvert Analysis and Design; Bentley Culvert Master (Version 3.1); 7 Bentley Systems, Inc. 8

• gINT: Geotechnical and Geoenvironmental Software; gINT Version 8.0; gINT 9 Software, Inc. 10

• Microsoft Excel (2010): A Software for Storing, Organizing and Manipulating Data; 11 Microsoft Corporation 12

• Microsoft Word (2010): Word Processing Software; Microsoft Corporation 13

• Primavera (Version 3.0): Project Management Software; Primavera Systems, Inc. 14

• SAP2000: Structural Analysis and Design Software; CSI, Computer & Structures, 15 Inc. 16

• SEEP/W: Seepage Analysis Software; GeoStudio (2007, version 7.15); GEO-SLOPE 17 International Ltd. 18

• SLOPE/W: Slope Stability Software; Geo Studio (2007, version 7.15); GEO-SLOPE 19 International Ltd. 20

• Specifications-Kept-Intact (SpecsIntact, Version 4.4.2): An Automated System for 21 Preparing Standardized Facility Construction Specifications; National Aeronautics 22 and Space Administration - Information Management Communications Services, 23 Kennedy Space Center. 24

• MII (Version 3.0 Build IV): Micro-Computer Aided Cost Estimating System; Tri-25 Services Automated Cost Engineering System Suite of Software Tools, MCACES 26 Second Generation; Project Time & Cost, Inc. 27

• UTEXAS4: A Computer Program for Slope Stability Calculations; (1999); Shinoak 28 Software. 29

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URS Group, Inc. 3-6 USIBWC, El Paso, Texas

3.6 Government-Provided Information 1

The USIBWC provided the following project documents to URS for preparation of this DDR and 2 the Plans and Specifications for the Ysleta to Fabens improvements project. 3

• USACE, Condition Assessment of U.S. International Boundary and Water 4 Commission, Texas and New Mexico Levees, 2004. 5

• HEC-RAS Model, including the water surface comparison table for the El Paso 6 IBWC Levee Project along the Rio Grande. 7

• USIBWC, "Final Environmental Assessment: Improvements to the Rio Grande 8 Rectification Project" Engineering Research and Development Center Levee 9 Assessment; March, 2009. 10

• USIBWC existing top of levee elevation tables titled" TOLE CL Rivers Fabens 11 Project.xls." 12

• As-Builts: 13 o EPWCID No. 1 drawings showing details for the intercepting drains entitled 14 "Riverside_Intercept_Drain," Drawing No. 23-503-6570 and "Border_Drain," 15 Drawing No. 23-503-6507. 16 o EPWCID No.1 drawing set showing details for the wasteway structures, 17 "Riverside WW1 Impvts." 18 o USIBWC drawings showing plats for the Rio Grande updated river alignment 19 from the natural alignment. Dated 1930s, "Engineering Office Files (EOFs)," 20 Drawing Nos. EOF's 51-130 and EOF's 251-279 and the EOF index sheets. 21 o USIBWC drawing set showing details for the levee construction downstream, 22 "Rehabilitation Improvements for Fabens Levee Reach in El Paso County." 23

• Proposed Drawings (2011) and As-builts (2012): 24 o USACE/Department of Homeland Security Drawings showing the Border Patrol 25 proposed access bridges crossing along the levee alignment entitled "Design 26 Analysis Report." 27 o USACE/Department of Homeland Security Drawings showing the Border Patrol 28 proposed fencing adjacent to the levee alignment entitled "Fence Project K-2B." 29 o USACE/Department of Homeland Security Drawings showing the Border Patrol 30 proposed fence closure adjacent to the levee alignment entitled "K-2C Fence 31 Closures." 32

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URS Group, Inc. 3-7 USIBWC, El Paso, Texas o USACE/Department of Homeland Security Drawings showing the Border Patrol 1 proposed levee access ramp location and grading near the bridges adjacent to the 2 levee alignment entitled "Levee Ramps." 3

• Other Information Provided by Client: 4 o USIBWC drawings showing parcel maps along the Rio Grande, "Parcels-Treaty 5 Maps," Parts I, II, and III. 6 o USIBWC drawings showing right of way parcel maps along the Rio Grande dated 7 from 1946, " Rio Grande Rectification Project Right of Way 1946." 8

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URS Group, Inc. 4-1 USIBWC, El Paso, Texas

4.0 ENGINEERING DESIGN 1

4.1 Hydrology and Hydraulics 2

4.1.1 Background 3

In December 2007, USIBWC completed a hydraulic model of the RGRP to analyze existing 4 conditions along the Rio Grande. The detailed technical analysis was performed using USACE's 5 HEC-RAS Version 3.12. The study determined the capacity of the existing RGRP structure to 6 convey the design flood flows without encroaching on the freeboard. At the time that the 7 analysis was completed, the proposed freeboard for the Rio Grande levee was 3 feet. 8

The HEC-RAS model provided by the USIBWC shows that flows are conservatively assumed 9 throughout the watershed at 11,000 cubic feet per second (cfs). Velocities in the Rio Grande 10 channel range from 5.45 to 15.75 feet per second (fps) along the alignment; however, the 11 velocities are much lower along the left bank of the floodway and on the side slopes of the levee. 12 These velocities range from 0.48 to 1.55 fps. 13

4.1.2 Hydraulic Features 14

The hydraulic features that will convey the flow of water along the Ysleta to Fabens Reach are 15 Wasteway No. 1 and Wasteway No. 2. Their specific locations are listed in Table 4-1. 16

Table 4-1. Drainage Structures 17

Structure STA / Location WSE Existing Size Proposed Size Wasteway No. 1 933+29.42 3650.75 5 barrels; 5 ft x 6 ft Same as Existing Wasteway No. 2 1219+22.98 3630.69 3 barrels; 5 ft x 6 ft Same as Existing

4.1.3 Drainage Structures 19

Two drainage structures along the Ysleta to Fabens levee were constructed as part of the original 20 levee. These structures still exist with the original slide gates, and gate actuators. The 100% 21 design of the levee rehabilitation includes replacement of these two drainage structures. The 22 recommendation is to reconstruct these two structures due to concrete spalling and failure to 23 meet USACE criteria. The USIBWC indicated that there was no need to increase the size of the 24 culverts. Since the existing drainage structures will be replaced with equally sized structures, 25 drainage calculations are not required. Table 4-1 lists the two drainage structures that will be 26 reconstructed along Ysleta to Fabens. 27

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URS Group, Inc. 4-2 USIBWC, El Paso, Texas

4.2 Geotechnical 1

4.2.1 Objectives 2

The geotechnical investigation consisted of explorations and geotechnical analyses for the 15.8-3 mile levee segment from Riverside Dam in the Ysleta region of El Paso to Fabens, TX. The 4 project alignment can be seen on Figure 1. Borings were drilled to determine subsurface 5 conditions of soils and to obtain soil samples for laboratory testing. The subsurface information 6 collected was supplemented by the USACE report "Condition Assessment of the USIBWC, 7 Texas and New Mexico Levees," dated June 2004. The investigation and analysis were 8 performed by RKCI under contract with URS. 9

Geotechnical laboratory tests were performed on selected samples to assess index and 10 engineering properties of the various soil units. Based on the laboratory test results, geotechnical 11 analyses were performed to assess the levee system's anticipated performance for seepage and 12 slope stability for the 100-year-storm design flood event. Remedial options were assessed where 13 analyses indicated a deficiency in levee performance. 14

For more information, refer to Appendix B, which contains the following information: 15

• Geotechnical Analysis and Engineering Evaluation ("Geotechnical Report"), 16 submitted by RKCI in November 2010; and 17

• Supplemental Geotechnical Analysis for Final Design ("Geotechnical Supplement") 18 submitted by RKCI in December 2011 and revised in June 2012. 19

4.2.2 Background 20

Levee System Components 21

This project, like others surrounding the Rio Grande in this area, is historically linked to 22 irrigation of local farmlands and sharing irrigation water between the U.S. and Mexico. This 23 objective is accomplished through a network of irrigation canals that parallel the levee for 24 portions of this project.