J.09_TR-03-04_Condition_Assessment_of_USIBWC _Levees _Volume_II.pdf

E n g in ee r

R es ea rc h a n d

D ev el o p m en t C en te r E

R D

C T

R -0

3-

October 2003

Joseph B. Dunbar, Robert F. Ballard, William L. Murphy, Thomas E. McGill, Jose L. Llopis, Linda P. Peyman-Dove, Michael J. Bishop

Condition Assessment of U.S. International Boundary and Water Commission, Lower Rio Grande Valley Levees, South Texas

US Army Corps of Engineers Engineer Research and Development Center

Prepared for the United States International Boundary and Water Commission

Volume II: Plates

Distribution authorized to U.S. Government agencies only; administrative or operational use; October 2003. Other requests for this document shall be referred to:

Geotechnical and Structures Laboratory, ATTN: CEERD-GS-G, U.S. Army Engineer Research and Development Center, 3909 Halls Ferry Road, Vicksburg, MS 39180-6199.

Plate 1 Segment Locations

Plate 2 DIGHEM Survey – 102 kHz

Plate 3 DIGHEM Survey – 25 kHz

Plate 4 DIGHEM Survey – 6200 kHz

Plate 5 DIGHEM Survey – 1500 kHz

Plate 6 DIGHEM Survey 390 kHz

Plate 7 Magnetometer Survey

Plate 8 Performance History

Plate 9 Construction History

Plate 10 Visual Inspection Condition

Plate 11 Material Type

Plate 12 Typographic Irregularity

Plate 13 Slope of Stability

Plate 14 Manmade Intrusions

Plate 15 Geology

Plate 16 Proximity of Borrow Areas

Plate 17 Anomalies

Plate 18 Overall Levee Condition

Plate 19 Geologic Sections A-A’ and B-B’

Plate 20 Geologic Section C-C’

Pharr Pharr

Olmito Olmito

Donna Donna

Hidalgo Hidalgo

Mission Mission La Joya La Joya La Feria La Feria

Edcouch Edcouch

Willamar Willamar

Progreso Progreso

La Leona La Leona

Harlingen Harlingen Mercedes Mercedes

Paso Real Paso Real

Southmost Southmost

Las Milpas Las Milpas La Paloma La Paloma

Palmito Hill Palmito Hill

Santa Rosa Santa Rosa

Santa Maria Santa Maria

Hawk Island Hawk Island

Willamar SW Willamar SW

San Juan SE San Juan SE

East Brownsville East Brownsville

Southmost OE E Southmost OE E

West Brownsville West Brownsville

Hidalgo CountyHidalgo County

Cameron CountyCameron County

Willacy CountyWillacy County

MI-1MI-1

SJ-6SJ-6

MI-3MI-3

WB-3WB-3

WB-1WB-1

LP-1LP-1

MI-7MI-7

SM-9SM-9

PG-13PG-13

SR-2SR-2

PR-6PR-6

PR-2PR-2

SM-10SM-10

LF-8LF-8

SJ-2SJ-2

MC-1MC-1

MC-6MC-6

PA-7PA-7

SJ-1SJ-1

WB-2WB-2

WS-10WS-10

LP-2LP-2

SJ-11SJ-11

SR-7SR-7

HD-2HD-2

SM-3SM-3

SJ-7SJ-7

ED-2ED-2

EB-2EB-2

WS-4WS-4

SJ-9SJ-9

MC-5MC-5

SO-6SO-6

LL-2LL-2

PG-6PG-6

SR-9SR-9

SR-1SR-1

LM-4LM-4

MC-12MC-12

PG-11PG-11

LM-6LM-6

PG-5PG-5

PA-8PA-8

DO-1DO-1

PA-2PA-2

WS-5WS-5

SO-2SO-2

MC-8MC-8

PR-5PR-5

WB-4WB-4

LP-5LP-5

PG-7PG-7

ED-7ED-7

MC-2MC-2

MC-3MC-3

SM-8SM-8

MC-10MC-10

HI-1HI-1

ED-8ED-8

EB-7EB-7

WS-3WS-3

LF-9LF-9

ED-9ED-9

PR-7PR-7

MI-2MI-2

PR-1PR-1

SM-11SM-11

PR-4PR-4

LP-3LP-3

ED-3ED-3

PG-14PG-14

ED-4ED-4

PA-3PA-3

LF-4LF-4

SR-6SR-6

SJ-5SJ-5

EB-3EB-3

WI-1WI-1

SR-8SR-8

LF-7LF-7

SR-4SR-4

WS-9WS-9

LJ-3LJ-3

SJ-16SJ-16

PA-9PA-9

SJ-4SJ-4

LM-3LM-3

MC-9MC-9

SJ-15SJ-15

PG-3PG-3

PG-12PG-12

LP-4LP-4

MC-7MC-7

MC-4MC-4

WS-1WS-1

PG-9PG-9

PG-8PG-8

MI-9MI-9

LM-2LM-2

PG-1PG-1

SJ-12SJ-12

PA-4PA-4

PA-1PA-1

PA-6PA-6

HA-1HA-1

OL-1OL-1

PG-10PG-10

SJ-10SJ-10

MI-6MI-6

LJ-5LJ-5

SR-5SR-5

WS-11WS-11

ED-1ED-1

WS-6WS-6

PR-8PR-8

LJ-4LJ-4

SJ-3SJ-3

DO-4DO-4

ED-5ED-5

PG-4PG-4

SO-4SO-4

SM-7SM-7

MI-5MI-5

SJ-14SJ-14

HD-1HD-1

WS-8WS-8

LF-1LF-1

MI-4MI-4

SO-3SO-3

PA-10PA-10

EB-6EB-6

LF-5LF-5

PA-5PA-5

LJ-2LJ-2

SM-5SM-5

LM-5LM-5

SJ-8SJ-8

LF-3LF-3

PR-3PR-3

SM-4SM-4

ED-6ED-6

SM-6SM-6

LF-2LF-2

EB-1EB-1

SO-1SO-1

EB-5EB-5

LJ-1LJ-1

PH-1PH-1

MI-8MI-8

LM-1LM-1

DO-3DO-3

DO-2DO-2

SJ-13SJ-13

PG-2PG-2

MC-11MC-11

ED-10ED-10

SR-3SR-3

WS-7WS-7

WS-2WS-2

PR-9PR-9

LF-10LF-10

LF-6LF-6

EB-4EB-4

SO-5SO-5

SM-1SM-1 SM-2SM-2

98°30'0"W

98°30'0"W

98°22'30"W

98°22'30"W

98°15'0"W

98°15'0"W

98°7'30"W

98°7'30"W

98°0'0"W

98°0'0"W

97°52'30"W

97°52'30"W

97°45'0"W

97°45'0"W

97°37'30"W

97°37'30"W

97°30'0"W

97°30'0"W

97°22'30"W

97°22'30"W

97°15'0"W

97°15'0"W

97°7'30"W

97°7'30"W

°4 5'

0" N

°4

5' 0"

N

°5

2'

"N

°5

2'

"N

°0

'0 "N

°0

'0 "N

°7

'3 0"

N

°7

'3 0"

N

°1

5' 0"

N

°1

5' 0"

N

°2

2'

"N

°2

2'

"N

°3

0' 0"

N

°3

0' 0"

N

Texas

Lower Rio Grande Valley

Segment Locations

Plate 1

Condition Assessment of US International Boundary and Water Commission

Lower Rio Grande Valley Levees 1:185,000Scale =

0 5 10 15 20 25 301 2 3 4 Miles

0 10 20 30 405 Kilometers

Segment Locations Condition Assessment of US International Boundary and Water Commission Lower Rio Grande Valley Levees

Table of Contents

Plate 1 : Segment Locations Plate 2 : DIGHEM Survey - 102 kHz Plate 3 : DIGHEM Survey - 25 kHz Plate 4 : DIGHEM Survey - 6200 Hz Plate 5 : DIGHEM Survey - 1500 Hz Plate 6 : DIGHEM Survey - 380 Hz Plate 7 : Magnetometer Survey Plate 8 : Performance History Plate 9 : Construction History Plate 10 : Visual Inspection Condition

Plate 11 : Material Type Plate 12 : Topographic Irregularity Plate 13 : Slope Stability Plate 14 : Manmade Intrusions Plate 15 : Geology Plate 16 : Proximity of Borrow Areas Plate 17 : Anomalies Plate 18 : Overall Levee Condition Plate 19 : Geologic Sections A-A' and B-B' Plate 20 : Geologic Section C-C'

Donna Donna

Hidalgo Hidalgo

Mission Mission La Joya La Joya La Feria La Feria

Edcouch Edcouch

Willamar Willamar

Progreso Progreso

La Leona La Leona

Harlingen Harlingen Mercedes Mercedes

Paso Real Paso Real

Southmost Southmost

Las Milpas Las Milpas La Paloma La Paloma

Palmito Hill Palmito Hill

Santa Rosa Santa Rosa

Santa Maria Santa Maria

Hawk Island Hawk Island

Willamar SW Willamar SW

San Juan SE San Juan SE

East Brownsville East Brownsville

Southmost OE E Southmost OE E

West Brownsville West Brownsville

Hidalgo CountyHidalgo County

Cameron CountyCameron County

Willacy CountyWillacy County

98°30'0"W

98°30'0"W

98°22'30"W

98°22'30"W

98°15'0"W

98°15'0"W

98°7'30"W

98°7'30"W

98°0'0"W

98°0'0"W

97°52'30"W

97°52'30"W

97°45'0"W

97°45'0"W

97°37'30"W

97°37'30"W

97°30'0"W

97°30'0"W

97°22'30"W

97°22'30"W

97°15'0"W

97°15'0"W

97°7'30"W

97°7'30"W

°4 5'

0" N

°4

5' 0"

N

°5

2'

"N

°5

2'

"N

°0

'0 "N

°0

'0 "N

°7

'3 0"

N

°7

'3 0"

N

°1

5' 0"

N

°1

5' 0"

N

°2

2'

"N

°2

2'

"N

°3

0' 0"

N

°3

0' 0"

N

Texas

Lower Rio Grande Valley

Flown by . . . . . . . . . . . Fugro Airborne Surveys Date Flown . . . . . . . . . . July, 2001 Navigation . . . . . . . . . . Differentially-corrected GPS Data reduction grid interval . . . . 12.5 meters Terrain clearance . . . . . . . . Helicopter 57 m Electromagnetic sensor 30 m Magnetometer 30 m Data sampling interval . . . . . . 0.1 second Magnetometer / sensitivity . . . . . Cesium / 0.01 nT Electromagnetic system . . . . . . DIGHEM VRES

Frequency Sensitivity Coil Orientation

380 Hz 0.12 ppm Horizontal coplanar 1500 Hz 0.12 ppm Horizontal coplanar 6200 Hz 0.24 ppm Horizontal coplanar 25000 Hz 0.44 ppm Horizontal coplanar 102000 Hz 0.44 ppm Horizontal coplanar

TECHNICAL SUMMARY

LRGV DIGHEM Survey - 102 kHz

Plate 2

Condition Assessment of US International Boundary and Water Commission

Lower Rio Grande Valley Levees 1:185,000Scale =

0 5 10 15 20 25 301 2 3 4 Miles

0 10 20 30 405 Kilometers

1000 +

Conductivity mS/m

Inferred Material-Type

Clay

Silty Clay

Silt

Silty Sand

Sand

LRGV DIGHEM Survey - 102 kHz

Condition Assessment of US International Boundary and Water Commission Lower Rio Grande Valley Levees

Donna Donna

Hidalgo Hidalgo

Mission Mission La Joya La Joya La Feria La Feria

Edcouch Edcouch

Willamar Willamar

Progreso Progreso

La Leona La Leona

Harlingen Harlingen Mercedes Mercedes

Paso Real Paso Real

Southmost Southmost

Las Milpas Las Milpas La Paloma La Paloma

Palmito Hill Palmito Hill

Santa Rosa Santa Rosa

Santa Maria Santa Maria

Hawk Island Hawk Island

Willamar SW Willamar SW

San Juan SE San Juan SE

East Brownsville East Brownsville

Southmost OE E Southmost OE E

West Brownsville West Brownsville

Hidalgo CountyHidalgo County

Cameron CountyCameron County

Willacy CountyWillacy County

98°30'0"W

98°30'0"W

98°22'30"W

98°22'30"W

98°15'0"W

98°15'0"W

98°7'30"W

98°7'30"W

98°0'0"W

98°0'0"W

97°52'30"W

97°52'30"W

97°45'0"W

97°45'0"W

97°37'30"W

97°37'30"W

97°30'0"W

97°30'0"W

97°22'30"W

97°22'30"W

97°15'0"W

97°15'0"W

97°7'30"W

97°7'30"W

°4 5'

0" N

°4

5' 0"

N

°5

2'

"N

°5

2'

"N

°0

'0 "N

°0

'0 "N

°7

'3 0"

N

°7

'3 0"

N

°1

5' 0"

N

°1

5' 0"

N

°2

2'

"N

°2

2'

"N

°3

0' 0"

N

°3

0' 0"

N

Texas

Lower Rio Grande Valley

Flown by . . . . . . . . . . . Fugro Airborne Surveys Date Flown . . . . . . . . . . July, 2001 Navigation . . . . . . . . . . Differentially-corrected GPS Data reduction grid interval . . . . 12.5 meters Terrain clearance . . . . . . . . Helicopter 57 m Electromagnetic sensor 30 m Magnetometer 30 m Data sampling interval . . . . . . 0.1 second Magnetometer / sensitivity . . . . . Cesium / 0.01 nT Electromagnetic system . . . . . . DIGHEM VRES

Frequency Sensitivity Coil Orientation

380 Hz 0.12 ppm Horizontal coplanar 1500 Hz 0.12 ppm Horizontal coplanar 6200 Hz 0.24 ppm Horizontal coplanar 25000 Hz 0.44 ppm Horizontal coplanar 102000 Hz 0.44 ppm Horizontal coplanar

TECHNICAL SUMMARY

LRGV DIGHEM Survey - 25 kHz

Plate 3

Condition Assessment of US International Boundary and Water Commission

Lower Rio Grande Valley Levees 1:185,000Scale =

0 5 10 15 20 25 301 2 3 4 Miles

0 10 20 30 405 Kilometers

1000 +

Conductivity mS/m

Inferred Material-Type

Clay

Silty Clay

Silt

Silty Sand

Sand

LRGV DIGHEM Survey - 25 kHz

Condition Assessment of US International Boundary

Donna Donna

Hidalgo Hidalgo

Mission Mission La Joya La Joya La Feria La Feria

Edcouch Edcouch

Willamar Willamar

Progreso Progreso

La Leona La Leona

Harlingen Harlingen Mercedes Mercedes

Paso Real Paso Real

Southmost Southmost

Las Milpas Las Milpas La Paloma La Paloma

Palmito Hill Palmito Hill

Santa Rosa Santa Rosa

Santa Maria Santa Maria

Hawk Island Hawk Island

Willamar SW Willamar SW

San Juan SE San Juan SE

East Brownsville East Brownsville

Southmost OE E Southmost OE E

West Brownsville West Brownsville

Hidalgo CountyHidalgo County

Cameron CountyCameron County

Willacy CountyWillacy County

98°30'0"W

98°30'0"W

98°22'30"W

98°22'30"W

98°15'0"W

98°15'0"W

98°7'30"W

98°7'30"W

98°0'0"W

98°0'0"W

97°52'30"W

97°52'30"W

97°45'0"W

97°45'0"W

97°37'30"W

97°37'30"W

97°30'0"W

97°30'0"W

97°22'30"W

97°22'30"W

97°15'0"W

97°15'0"W

97°7'30"W

97°7'30"W

°4 5'

0" N

°4

5' 0"

N

°5

2'

"N

°5

2'

"N

°0

'0 "N

°0

'0 "N

°7

'3 0"

N

°7

'3 0"

N

°1

5' 0"

N

°1

5' 0"

N

°2

2'

"N

°2

2'

"N

°3

0' 0"

N

°3

0' 0"

N

Texas

Lower Rio Grande Valley

Flown by . . . . . . . . . . . Fugro Airborne Surveys Date Flown . . . . . . . . . . July, 2001 Navigation . . . . . . . . . . Differentially-corrected GPS Data reduction grid interval . . . . 12.5 meters Terrain clearance . . . . . . . . Helicopter 57 m Electromagnetic sensor 30 m Magnetometer 30 m Data sampling interval . . . . . . 0.1 second Magnetometer / sensitivity . . . . . Cesium / 0.01 nT Electromagnetic system . . . . . . DIGHEM VRES

Frequency Sensitivity Coil Orientation

380 Hz 0.12 ppm Horizontal coplanar 1500 Hz 0.12 ppm Horizontal coplanar 6200 Hz 0.24 ppm Horizontal coplanar 25000 Hz 0.44 ppm Horizontal coplanar 102000 Hz 0.44 ppm Horizontal coplanar

TECHNICAL SUMMARY

LRGV DIGHEM Survey - 6200 Hz

Plate 4

Condition Assessment of US International Boundary and Water Commission

Lower Rio Grande Valley Levees 1:185,000Scale =

0 5 10 15 20 25 301 2 3 4 Miles

0 10 20 30 405 Kilometers

1000 +

Conductivity mS/m

Inferred Material-Type

Clay

Silty Clay

Silt

Silty Sand

Sand

LRGV DIGHEM Survey - 6200 Hz

Condition Assessment of US International Boundary

Donna Donna

Hidalgo Hidalgo

Mission Mission La Joya La Joya La Feria La Feria

Edcouch Edcouch

Willamar Willamar

Progreso Progreso

La Leona La Leona

Harlingen Harlingen Mercedes Mercedes

Paso Real Paso Real

Southmost Southmost

Las Milpas Las Milpas La Paloma La Paloma

Palmito Hill Palmito Hill

Santa Rosa Santa Rosa

Santa Maria Santa Maria

Hawk Island Hawk Island

Willamar SW Willamar SW

San Juan SE San Juan SE

East Brownsville East Brownsville

Southmost OE E Southmost OE E

West Brownsville West Brownsville

Hidalgo CountyHidalgo County

Cameron CountyCameron County

Willacy CountyWillacy County

98°30'0"W

98°30'0"W

98°22'30"W

98°22'30"W

98°15'0"W

98°15'0"W

98°7'30"W

98°7'30"W

98°0'0"W

98°0'0"W

97°52'30"W

97°52'30"W

97°45'0"W

97°45'0"W

97°37'30"W

97°37'30"W

97°30'0"W

97°30'0"W

97°22'30"W

97°22'30"W

97°15'0"W

97°15'0"W

97°7'30"W

97°7'30"W

°4 5'

0" N

°4

5' 0"

N

°5

2'

"N

°5

2'

"N

°0

'0 "N

°0

'0 "N

°7

'3 0"

N

°7

'3 0"

N

°1

5' 0"

N

°1

5' 0"

N

°2

2'

"N

°2

2'

"N

°3

0' 0"

N

°3

0' 0"

N

Texas

Lower Rio Grande Valley

Flown by . . . . . . . . . . . Fugro Airborne Surveys Date Flown . . . . . . . . . . July, 2001 Navigation . . . . . . . . . . Differentially-corrected GPS Data reduction grid interval . . . . 12.5 meters Terrain clearance . . . . . . . . Helicopter 57 m Electromagnetic sensor 30 m Magnetometer 30 m Data sampling interval . . . . . . 0.1 second Magnetometer / sensitivity . . . . . Cesium / 0.01 nT Electromagnetic system . . . . . . DIGHEM VRES

Frequency Sensitivity Coil Orientation

380 Hz 0.12 ppm Horizontal coplanar 1500 Hz 0.12 ppm Horizontal coplanar 6200 Hz 0.24 ppm Horizontal coplanar 25000 Hz 0.44 ppm Horizontal coplanar 102000 Hz 0.44 ppm Horizontal coplanar

TECHNICAL SUMMARY

LRGV DIGHEM Survey - 1500 Hz

Plate 5

Condition Assessment of US International Boundary and Water Commission

Lower Rio Grande Valley Levees 1:185,000Scale =

0 5 10 15 20 25 301 2 3 4 Miles

0 10 20 30 405 Kilometers

1000 +

Conductivity mS/m

Inferred Material-Type

Clay

Silty Clay

Silt

Silty Sand

Sand

LRGV DIGHEM Survey - 1500 Hz

Condition Assessment of US International Boundary

Donna Donna

Hidalgo Hidalgo

Mission Mission La Joya La Joya La Feria La Feria

Edcouch Edcouch

Willamar Willamar

Progreso Progreso

La Leona La Leona

Harlingen Harlingen Mercedes Mercedes

Paso Real Paso Real

Southmost Southmost

Las Milpas Las Milpas La Paloma La Paloma

Palmito Hill Palmito Hill

Santa Rosa Santa Rosa

Santa Maria Santa Maria

Hawk Island Hawk Island

Willamar SW Willamar SW

San Juan SE San Juan SE

East Brownsville East Brownsville

Southmost OE E Southmost OE E

West Brownsville West Brownsville

Hidalgo CountyHidalgo County

Cameron CountyCameron County

Willacy CountyWillacy County

98°30'0"W

98°30'0"W

98°22'30"W

98°22'30"W

98°15'0"W

98°15'0"W

98°7'30"W

98°7'30"W

98°0'0"W

98°0'0"W

97°52'30"W

97°52'30"W

97°45'0"W

97°45'0"W

97°37'30"W

97°37'30"W

97°30'0"W

97°30'0"W

97°22'30"W

97°22'30"W

97°15'0"W

97°15'0"W

97°7'30"W

97°7'30"W

°4 5'

0" N

°4

5' 0"

N

°5

2'

"N

°5

2'

"N

°0

'0 "N

°0

'0 "N

°7

'3 0"

N

°7

'3 0"

N

°1

5' 0"

N

°1

5' 0"

N

°2

2'

"N

°2

2'

"N

°3

0' 0"

N

°3

0' 0"

N

Texas

Lower Rio Grande Valley

Flown by . . . . . . . . . . . Fugro Airborne Surveys Date Flown . . . . . . . . . . July, 2001 Navigation . . . . . . . . . . Differentially-corrected GPS Data reduction grid interval . . . . 12.5 meters Terrain clearance . . . . . . . . Helicopter 57 m Electromagnetic sensor 30 m Magnetometer 30 m Data sampling interval . . . . . . 0.1 second Magnetometer / sensitivity . . . . . Cesium / 0.01 nT Electromagnetic system . . . . . . DIGHEM VRES

Frequency Sensitivity Coil Orientation

380 Hz 0.12 ppm Horizontal coplanar 1500 Hz 0.12 ppm Horizontal coplanar 6200 Hz 0.24 ppm Horizontal coplanar 25000 Hz 0.44 ppm Horizontal coplanar 102000 Hz 0.44 ppm Horizontal coplanar

TECHNICAL SUMMARY

LRGV DIGHEM Survey - 380 Hz

Plate 6

Condition Assessment of US International Boundary and Water Commission

Lower Rio Grande Valley Levees 1:185,000Scale =

0 5 10 15 20 25 301 2 3 4 Miles

0 10 20 30 405 Kilometers

1000 +

Conductivity mS/m

Inferred Material-Type

Clay

Silty Clay

Silt

Silty Sand

Sand

LRGV DIGHEM Survey - 380 Hz

Condition Assessment of US International Boundary

Donna Donna

Hidalgo Hidalgo

Mission Mission La Joya La Joya La Feria La Feria

Edcouch Edcouch

Willamar Willamar

Progreso Progreso

La Leona La Leona

Harlingen Harlingen Mercedes Mercedes

Paso Real Paso Real

Southmost Southmost

Las Milpas Las Milpas La Paloma La Paloma

Palmito Hill Palmito Hill

Santa Rosa Santa Rosa

Santa Maria Santa Maria

Hawk Island Hawk Island

Willamar SW Willamar SW

San Juan SE San Juan SE

East Brownsville East Brownsville

Southmost OE E Southmost OE E

West Brownsville West Brownsville

Hidalgo CountyHidalgo County

Cameron CountyCameron County

Willacy CountyWillacy County

98°30'0"W

98°30'0"W

98°22'30"W

98°22'30"W

98°15'0"W

98°15'0"W

98°7'30"W

98°7'30"W

98°0'0"W

98°0'0"W

97°52'30"W

97°52'30"W

97°45'0"W

97°45'0"W

97°37'30"W

97°37'30"W

97°30'0"W

97°30'0"W

97°22'30"W

97°22'30"W

97°15'0"W

97°15'0"W

°4 5'

0" N

°4

5' 0"

N

°5

2'

"N

°5

2'

"N

°0

'0 "N

°0

'0 "N

°7

'3 0"

N

°7

'3 0"

N

°1

5' 0"

N

°1

5' 0"

N

°2

2'

"N

°2

2'

"N

°3

0' 0"

N

°3

0' 0"

N

Texas

Lower Rio Grande Valley

Flown by . . . . . . . . . . . Fugro Airborne Surveys Date Flown . . . . . . . . . . July, 2001 Navigation . . . . . . . . . . Differentially-corrected GPS Data reduction grid interval . . . . 12.5 meters Terrain clearance . . . . . . . . Helicopter 57 m Electromagnetic sensor 30 m Magnetometer 30 m Data sampling interval . . . . . . 0.1 second Magnetometer / sensitivity . . . . . Cesium / 0.01 nT Electromagnetic system . . . . . . DIGHEM VRES

Frequency Sensitivity Coil Orientation

380 Hz 0.12 ppm Horizontal coplanar 1500 Hz 0.12 ppm Horizontal coplanar 6200 Hz 0.24 ppm Horizontal coplanar 25000 Hz 0.44 ppm Horizontal coplanar 102000 Hz 0.44 ppm Horizontal coplanar

TECHNICAL SUMMARY

Magnetometer Survey

Plate 7

Condition Assessment of US International Boundary and Water Commission

Lower Rio Grande Valley Levees 1:185,000Scale =

0 5 10 15 20 25 301 2 3 4 Miles

0 10 20 30 405 Kilometers

Magnetometer Survey

Condition Assessment of US International Boundary and Water Commission Lower Rio Grande Valley Levees nT

-30

Donna Donna

Hidalgo Hidalgo

Mission Mission La Joya La Joya La Feria La Feria

Edcouch Edcouch

Willamar Willamar

Progreso Progreso

La Leona La Leona

Harlingen Harlingen Mercedes Mercedes

Paso Real Paso Real

Southmost Southmost

Las Milpas Las Milpas La Paloma La Paloma

Palmito Hill Palmito Hill

Santa Rosa Santa Rosa

Santa Maria Santa Maria

Hawk Island Hawk Island

Willamar SW Willamar SW

San Juan SE San Juan SE

East Brownsville East Brownsville

Southmost OE E Southmost OE E

West Brownsville West Brownsville

Hidalgo CountyHidalgo County

Cameron CountyCameron County

Willacy CountyWillacy County

98°30'0"W

98°30'0"W

98°22'30"W

98°22'30"W

98°15'0"W

98°15'0"W

98°7'30"W

98°7'30"W

98°0'0"W

98°0'0"W

97°52'30"W

97°52'30"W

97°45'0"W

97°45'0"W

97°37'30"W

97°37'30"W

97°30'0"W

97°30'0"W

97°22'30"W

97°22'30"W

97°15'0"W

97°15'0"W

°4 5'

0" N

°4

5' 0"

N

°5

2'

"N

°5

2'

"N

°0

'0 "N

°0

'0 "N

°7

'3 0"

N

°7

'3 0"

N

°1

5' 0"

N

°1

5' 0"

N

°2

2'

"N

°2

2'

"N

°3

0' 0"

N

°3

0' 0"

N

Texas

Lower Rio Grande Valley

Performance History

Plate 8

Condition Assessment of US International Boundary and Water Commission

Lower Rio Grande Valley Levees 1:185,000Scale =

0 5 10 15 20 25 301 2 3 4 Miles

0 10 20 30 405 Kilometers

Performance History

Condition Assessment of US International Boundary and Water Commission Lower Rio Grande Valley Levees

Performance History

* Note : Identifies a New Levee or a Levee not Maintained by the USIBWC

Color Value

No Data *

3 or 3.5

2 or 2.5

1 or 1.5

0 or 0.5

Best

Good

Intermediate

Marginal

Worst

Condition

Donna Donna

Hidalgo Hidalgo

Mission Mission La Joya La Joya La Feria La Feria

Edcouch Edcouch

Willamar Willamar

Progreso Progreso

La Leona La Leona

Harlingen Harlingen Mercedes Mercedes

Paso Real Paso Real

Southmost Southmost

Las Milpas Las Milpas La Paloma La Paloma

Palmito Hill Palmito Hill

Santa Rosa Santa Rosa

Santa Maria Santa Maria

Hawk Island Hawk Island

Willamar SW Willamar SW

San Juan SE San Juan SE

East Brownsville East Brownsville

Southmost OE E Southmost OE E

West Brownsville West Brownsville

Hidalgo CountyHidalgo County

Cameron CountyCameron County

Willacy CountyWillacy County

98°30'0"W

98°30'0"W

98°22'30"W

98°22'30"W

98°15'0"W

98°15'0"W

98°7'30"W

98°7'30"W

98°0'0"W

98°0'0"W

97°52'30"W

97°52'30"W

97°45'0"W

97°45'0"W

97°37'30"W

97°37'30"W

97°30'0"W

97°30'0"W

97°22'30"W

97°22'30"W

97°15'0"W

97°15'0"W

°4 5'

0" N

°4

5' 0"

N

°5

2'

"N

°5

2'

"N

°0

'0 "N

°0

'0 "N

°7

'3 0"

N

°7

'3 0"

N

°1

5' 0"

N

°1

5' 0"

N

°2

2'

"N

°2

2'

"N

°3

0' 0"

N

°3

0' 0"

N

Texas

Lower Rio Grande Valley

Construction History

Plate 9

Condition Assessment of US International Boundary and Water Commission

Lower Rio Grande Valley Levees 1:185,000Scale =

0 5 10 15 20 25 301 2 3 4 Miles

0 10 20 30 405 Kilometers

Construction History

Condition Assessment of US International Boundary and Water Commission Lower Rio Grande Valley Levees

Construction History

* Note : Identifies a New Levee or a Levee not Maintained by the USIBWC

Color Value

No Data *

3 or 3.5

2 or 2.5

1 or 1.5

0 or 0.5

Best

Good

Intermediate

Marginal

Donna Donna

Hidalgo Hidalgo

Mission Mission La Joya La Joya La Feria La Feria

Edcouch Edcouch

Willamar Willamar

Progreso Progreso

La Leona La Leona

Harlingen Harlingen Mercedes Mercedes

Paso Real Paso Real

Southmost Southmost

Las Milpas Las Milpas La Paloma La Paloma

Palmito Hill Palmito Hill

Santa Rosa Santa Rosa

Santa Maria Santa Maria

Hawk Island Hawk Island

Willamar SW Willamar SW

San Juan SE San Juan SE

East Brownsville East Brownsville

Southmost OE E Southmost OE E

West Brownsville West Brownsville

Hidalgo CountyHidalgo County

Cameron CountyCameron County

Willacy CountyWillacy County

98°30'0"W

98°30'0"W

98°22'30"W

98°22'30"W

98°15'0"W

98°15'0"W

98°7'30"W

98°7'30"W

98°0'0"W

98°0'0"W

97°52'30"W

97°52'30"W

97°45'0"W

97°45'0"W

97°37'30"W

97°37'30"W

97°30'0"W

97°30'0"W

97°22'30"W

97°22'30"W

97°15'0"W

97°15'0"W

°4 5'

0" N

°4

5' 0"

N

°5

2'

"N

°5

2'

"N

°0

'0 "N

°0

'0 "N

°7

'3 0"

N

°7

'3 0"

N

°1

5' 0"

N

°1

5' 0"

N

°2

2'

"N

°2

2'

"N

°3

0' 0"

N

°3

0' 0"

N

Texas

Lower Rio Grande Valley

Visual Inspection Condition

Plate 10

Condition Assessment of US International Boundary and Water Commission

Lower Rio Grande Valley Levees 1:185,000Scale =

0 5 10 15 20 25 301 2 3 4 Miles

0 10 20 30 405 Kilometers

Visual Inspection Condition

Condition Assessment of US International Boundary and Water Commission Lower Rio Grande Valley Levees

Visual Inspection Condition

* Note : Identifies a New Levee or a Levee not Maintained by the USIBWC

Color Value

No Data *

3 or 3.5

2 or 2.5

1 or 1.5

0 or 0.5

Best

Good

Intermediate

Marginal

Donna Donna

Hidalgo Hidalgo

Mission Mission La Joya La Joya La Feria La Feria

Edcouch Edcouch

Willamar Willamar

Progreso Progreso

La Leona La Leona

Harlingen Harlingen Mercedes Mercedes

Paso Real Paso Real

Southmost Southmost

Las Milpas Las Milpas La Paloma La Paloma

Palmito Hill Palmito Hill

Santa Rosa Santa Rosa

Santa Maria Santa Maria

Hawk Island Hawk Island

Willamar SW Willamar SW

San Juan SE San Juan SE

East Brownsville East Brownsville

Southmost OE E Southmost OE E

West Brownsville West Brownsville

Hidalgo CountyHidalgo County

Cameron CountyCameron County

Willacy CountyWillacy County

98°30'0"W

98°30'0"W

98°22'30"W

98°22'30"W

98°15'0"W

98°15'0"W

98°7'30"W

98°7'30"W

98°0'0"W

98°0'0"W

97°52'30"W

97°52'30"W

97°45'0"W

97°45'0"W

97°37'30"W

97°37'30"W

97°30'0"W

97°30'0"W

97°22'30"W

97°22'30"W

97°15'0"W

97°15'0"W

°4 5'

0" N

°4

5' 0"

N

°5

2'

"N

°5

2'

"N

°0

'0 "N

°0

'0 "N

°7

'3 0"

N

°7

'3 0"

N

°1

5' 0"

N

°1

5' 0"

N

°2

2'

"N

°2

2'

"N

°3

0' 0"

N

°3

0' 0"

N

Texas

Lower Rio Grande Valley

Material Type

Plate 11

Condition Assessment of US International Boundary and Water Commission

Lower Rio Grande Valley Levees 1:185,000Scale =

0 5 10 15 20 25 301 2 3 4 Miles

0 10 20 30 405 Kilometers

Material Type

Condition Assessment of US International Boundary and Water Commission Lower Rio Grande Valley Levees

Material Type

* Note : Identifies a New Levee or a Levee not Maintained by the USIBWC

Color Value

No Data *

3 or 3.5

2 or 2.5

1 or 1.5

0 or 0.5

Best

Good

Intermediate

Marginal

Worst

Condition Description

Mainly clay, low to moderate shrink-swell potential

Mainly clay, some mixed soils, high shrink-swell

Mixed soils (sand, silt, little clay)

Primarily sand and/or thin top-stratum

Sand and/or no top-stratum, thick sandy sub-stratum

Donna Donna

Hidalgo Hidalgo

Mission Mission La Joya La Joya La Feria La Feria

Edcouch Edcouch

Willamar Willamar

Progreso Progreso

La Leona La Leona

Harlingen Harlingen Mercedes Mercedes

Paso Real Paso Real

Southmost Southmost

Las Milpas Las Milpas La Paloma La Paloma

Palmito Hill Palmito Hill

Santa Rosa Santa Rosa

Santa Maria Santa Maria

Hawk Island Hawk Island

Willamar SW Willamar SW

San Juan SE San Juan SE

East Brownsville East Brownsville

Southmost OE E Southmost OE E

West Brownsville West Brownsville

Hidalgo CountyHidalgo County

Cameron CountyCameron County

Willacy CountyWillacy County

98°30'0"W

98°30'0"W

98°22'30"W

98°22'30"W

98°15'0"W

98°15'0"W

98°7'30"W

98°7'30"W

98°0'0"W

98°0'0"W

97°52'30"W

97°52'30"W

97°45'0"W

97°45'0"W

97°37'30"W

97°37'30"W

97°30'0"W

97°30'0"W

97°22'30"W

97°22'30"W

97°15'0"W

97°15'0"W

°4 5'

0" N

°4

5' 0"

N

°5

2'

"N

°5

2'

"N

°0

'0 "N

°0

'0 "N

°7

'3 0"

N

°7

'3 0"

N

°1

5' 0"

N

°1

5' 0"

N

°2

2'

"N

°2

2'

"N

°3

0' 0"

N

°3

0' 0"

N

Texas

Lower Rio Grande Valley

Topographic Irregularity

Plate 12

Condition Assessment of US International Boundary and Water Commission

Lower Rio Grande Valley Levees 1:185,000Scale =

0 5 10 15 20 25 301 2 3 4 Miles

0 10 20 30 405 Kilometers

Topographic Irregularity

Condition Assessment of US International Boundary and Water Commission Lower Rio Grande Valley Levees

Topographic Irregularity

* Note : Identifies a New Levee or a Levee not Maintained by the USIBWC

Color Value

No Data *

3 or 3.5

2 or 2.5

1 or 1.5

0 or 0.5

Best

Good

Intermediate

Marginal

Worst

Condition Description

Less than 6" deviation from local slope

6" to 12" deviation from local slope

12" to 18" deviation from local slope

18" to 24" deviation from local slope

Greater than 24" deviation from local slope

Donna Donna

Hidalgo Hidalgo

Mission Mission La Joya La Joya La Feria La Feria

Edcouch Edcouch

Willamar Willamar

Progreso Progreso

La Leona La Leona

Harlingen Harlingen Mercedes Mercedes

Paso Real Paso Real

Southmost Southmost

Las Milpas Las Milpas La Paloma La Paloma

Palmito Hill Palmito Hill

Santa Rosa Santa Rosa

Santa Maria Santa Maria

Hawk Island Hawk Island

Willamar SW Willamar SW

San Juan SE San Juan SE

East Brownsville East Brownsville

Southmost OE E Southmost OE E

West Brownsville West Brownsville

Hidalgo CountyHidalgo County

Cameron CountyCameron County

Willacy CountyWillacy County

98°30'0"W

98°30'0"W

98°22'30"W

98°22'30"W

98°15'0"W

98°15'0"W

98°7'30"W

98°7'30"W

98°0'0"W

98°0'0"W

97°52'30"W

97°52'30"W

97°45'0"W

97°45'0"W

97°37'30"W

97°37'30"W

97°30'0"W

97°30'0"W

97°22'30"W

97°22'30"W

97°15'0"W

97°15'0"W

°4 5'

0" N

°4

5' 0"

N

°5

2'

"N

°5

2'

"N

°0

'0 "N

°0

'0 "N

°7

'3 0"

N

°7

'3 0"

N

°1

5' 0"

N

°1

5' 0"

N

°2

2'

"N

°2

2'

"N

°3

0' 0"

N

°3

0' 0"

N

Texas

Lower Rio Grande Valley

Slope Stability

Plate 13

Condition Assessment of US International Boundary and Water Commission

Lower Rio Grande Valley Levees 1:185,000Scale =

0 5 10 15 20 25 301 2 3 4 Miles

0 10 20 30 405 Kilometers

Slope Stability

Condition Assessment of US International Boundary and Water Commission Lower Rio Grande Valley Levees

Slope Stability

* Note : Identifies a New Levee or a Levee not Maintained by the USIBWC

Color Value

No Data *

3 or 3.5

2 or 2.5

1 or 1.5

0 or 0.5

Best

Good

Intermediate

Marginal

Worst

Condition Description

Greater than 500 ft from river, clay levee, high conductivity

300 - 500 ft from river, clay levee with high shrink/swell potential, high conductivity, shallow borrow pit at toe

200 - 300 ft from river, clay levee, low conductivity foundation, shallow borrow pit at toe

100 - 200 ft from river, sandy levee or foundation, low conductivity

Less than 100 ft from river, sandy levee, low conductivity

Donna Donna

Hidalgo Hidalgo

Mission Mission La Joya La Joya La Feria La Feria

Edcouch Edcouch

Willamar Willamar

Progreso Progreso

La Leona La Leona

Harlingen Harlingen Mercedes Mercedes

Paso Real Paso Real

Southmost Southmost

Las Milpas Las Milpas La Paloma La Paloma

Palmito Hill Palmito Hill

Santa Rosa Santa Rosa

Santa Maria Santa Maria

Hawk Island Hawk Island

Willamar SW Willamar SW

San Juan SE San Juan SE

East Brownsville East Brownsville

Southmost OE E Southmost OE E

West Brownsville West Brownsville

Hidalgo CountyHidalgo County

Cameron CountyCameron County

Willacy CountyWillacy County

98°30'0"W

98°30'0"W

98°22'30"W

98°22'30"W

98°15'0"W

98°15'0"W

98°7'30"W

98°7'30"W

98°0'0"W

98°0'0"W

97°52'30"W

97°52'30"W

97°45'0"W

97°45'0"W

97°37'30"W

97°37'30"W

97°30'0"W

97°30'0"W

97°22'30"W

97°22'30"W

97°15'0"W

97°15'0"W

°4 5'

0" N

°4

5' 0"

N

°5

2'

"N

°5

2'

"N

°0

'0 "N

°0

'0 "N

°7

'3 0"

N

°7

'3 0"

N

°1

5' 0"

N

°1

5' 0"

N

°2

2'

"N

°2

2'

"N

°3

0' 0"

N

°3

0' 0"

N

Texas

Lower Rio Grande Valley

Manmade Intrusions

Plate 14

Condition Assessment of US International Boundary and Water Commission

Lower Rio Grande Valley Levees 1:185,000Scale =

0 5 10 15 20 25 301 2 3 4 Miles

0 10 20 30 405 Kilometers

Manmade Intrusions

Condition Assessment of US International Boundary and Water Commission Lower Rio Grande Valley Levees

Manmade Intrusions

* Note : Identifies a New Levee or a Levee not Maintained by the USIBWC

Color Value

No Data *

3 or 3.5

2 or 2.5

1 or 1.5

0 or 0.5

Best

Good

Intermediate

Marginal

Worst

Condition Description

None

1 - 2, small diameter or EM signature

3 - 4, small diameter or EM signature

1 - 2, large diameter or EM signature

3 or more, large diameter or EM signature

Donna Donna

Hidalgo Hidalgo

Mission Mission La Joya La Joya La Feria La Feria

Edcouch Edcouch

Willamar Willamar

Progreso Progreso

La Leona La Leona

Harlingen Harlingen Mercedes Mercedes

Paso Real Paso Real

Southmost Southmost

Las Milpas Las Milpas La Paloma La Paloma

Palmito Hill Palmito Hill

Santa Rosa Santa Rosa

Santa Maria Santa Maria

Hawk Island Hawk Island

Willamar SW Willamar SW

San Juan SE San Juan SE

East Brownsville East Brownsville

Southmost OE E Southmost OE E

West Brownsville West Brownsville

Hidalgo CountyHidalgo County

Cameron CountyCameron County

Willacy CountyWillacy County

98°30'0"W

98°30'0"W

98°22'30"W

98°22'30"W

98°15'0"W

98°15'0"W

98°7'30"W

98°7'30"W

98°0'0"W

98°0'0"W

97°52'30"W

97°52'30"W

97°45'0"W

97°45'0"W

97°37'30"W

97°37'30"W

97°30'0"W

97°30'0"W

97°22'30"W

97°22'30"W

97°15'0"W

97°15'0"W

°4 5'

0" N

°4

5' 0"

N

°5

2'

"N

°5

2'

"N

°0

'0 "N

°0

'0 "N

°7

'3 0"

N

°7

'3 0"

N

°1

5' 0"

N

°1

5' 0"

N

°2

2'

"N

°2

2'

"N

°3

0' 0"

N

°3

0' 0"

N

Texas

Lower Rio Grande Valley

Geology

Plate 15

Condition Assessment of US International Boundary and Water Commission

Lower Rio Grande Valley Levees 1:185,000Scale =

0 5 10 15 20 25 301 2 3 4 Miles

0 10 20 30 405 Kilometers

Geology

Condition Assessment of US International Boundary and Water Commission Lower Rio Grande Valley Levees

Geology

* Note : Identifies a New Levee or a Levee not Maintained by the USIBWC

Color Value

No Data *

3 or 3.5

2 or 2.5

1 or 1.5

0 or 0.5

Best

Good

Intermediate

Marginal

Worst

Condition Description

No channel under levee, thick top-stratum

Clay-filled channel or course under levee (high conductivity)

Point bar with thin top-stratum, sandy sub-stratum, or levee crossing tributary valley or other relict drainage

Channel or course of intermediate conductivity (100 - 200 mS/m) under levee

Channel or course of low conductivity (less than 100 mS/m) under levee

Donna Donna

Hidalgo Hidalgo

Mission Mission La Joya La Joya La Feria La Feria

Edcouch Edcouch

Willamar Willamar

Progreso Progreso

La Leona La Leona

Harlingen Harlingen Mercedes Mercedes

Paso Real Paso Real

Southmost Southmost

Las Milpas Las Milpas La Paloma La Paloma

Palmito Hill Palmito Hill

Santa Rosa Santa Rosa

Santa Maria Santa Maria

Hawk Island Hawk Island

Willamar SW Willamar SW

San Juan SE San Juan SE

East Brownsville East Brownsville

Southmost OE E Southmost OE E

West Brownsville West Brownsville

Hidalgo CountyHidalgo County

Cameron CountyCameron County

Willacy CountyWillacy County

98°30'0"W

98°30'0"W

98°22'30"W

98°22'30"W

98°15'0"W

98°15'0"W

98°7'30"W

98°7'30"W

98°0'0"W

98°0'0"W

97°52'30"W

97°52'30"W

97°45'0"W

97°45'0"W

97°37'30"W

97°37'30"W

97°30'0"W

97°30'0"W

97°22'30"W

97°22'30"W

97°15'0"W

97°15'0"W

°4 5'

0" N

°4

5' 0"

N

°5

2'

"N

°5

2'

"N

°0

'0 "N

°0

'0 "N

°7

'3 0"

N

°7

'3 0"

N

°1

5' 0"

N

°1

5' 0"

N

°2

2'

"N

°2

2'

"N

°3

0' 0"

N

°3

0' 0"

N

Texas

Lower Rio Grande Valley

Proximity of Borrow Areas

Plate 16

Condition Assessment of US International Boundary and Water Commission

Lower Rio Grande Valley Levees 1:185,000Scale =

0 5 10 15 20 25 301 2 3 4 Miles

0 10 20 30 405 Kilometers

Proximity of Borrow Areas

Condition Assessment of US International Boundary and Water Commission Lower Rio Grande Valley Levees

Proximity of Borrow Areas

* Note : Identifies a New Levee or a Levee not Maintained by the USIBWC

Color Value

No Data *

3 or 3.5

2 or 2.5

1 or 1.5

0 or 0.5

Best

Good

Intermediate

Marginal

Worst

Condition Description

No borrow areas

Shallow borrow areas (less than 3 ft deep) located to landside toe

Shallow borrow areas (less than 3 ft deep) located to riverside toe

Borrow areas of intermediate depth (3 - 5 ft deep) located to riverside toe

Deep borrow areas (greater than 5 ft deep) located to riverside toe, standing water

Donna Donna

Hidalgo Hidalgo

Mission Mission La Joya La Joya La Feria La Feria

Edcouch Edcouch

Willamar Willamar

Progreso Progreso

La Leona La Leona

Harlingen Harlingen Mercedes Mercedes

Paso Real Paso Real

Southmost Southmost

Las Milpas Las Milpas La Paloma La Paloma

Palmito Hill Palmito Hill

Santa Rosa Santa Rosa

Santa Maria Santa Maria

Hawk Island Hawk Island

Willamar SW Willamar SW

San Juan SE San Juan SE

East Brownsville East Brownsville

Southmost OE E Southmost OE E

West Brownsville West Brownsville

Hidalgo CountyHidalgo County

Cameron CountyCameron County

Willacy CountyWillacy County

98°30'0"W

98°30'0"W

98°22'30"W

98°22'30"W

98°15'0"W

98°15'0"W

98°7'30"W

98°7'30"W

98°0'0"W

98°0'0"W

97°52'30"W

97°52'30"W

97°45'0"W

97°45'0"W

97°37'30"W

97°37'30"W

97°30'0"W

97°30'0"W

97°22'30"W

97°22'30"W

97°15'0"W

97°15'0"W

°4 5'

0" N

°4

5' 0"

N

°5

2'

"N

°5

2'

"N

°0

'0 "N

°0

'0 "N

°7

'3 0"

N

°7

'3 0"

N

°1

5' 0"

N

°1

5' 0"

N

°2

2'

"N

°2

2'

"N

°3

0' 0"

N

°3

0' 0"

N

Texas

Lower Rio Grande Valley

Anomalies

Plate 17

Condition Assessment of US International Boundary and Water Commission

Lower Rio Grande Valley Levees 1:185,000Scale =

0 5 10 15 20 25 301 2 3 4 Miles

0 10 20 30 405 Kilometers

Anomalies

Condition Assessment of US International Boundary and Water Commission Lower Rio Grande Valley Levees

Anomalies

* Note : Identifies a New Levee or a Levee not Maintained by the USIBWC

Color Value

No Data *

3 or 3.5

2 or 2.5

1 or 1.5

0 or 0.5

Best

Good

Intermediate

Marginal

Worst

Condition Description

Uniform conductivity

Low magnitude, slight contrast in conductivity

Low magnitude, moderate contrast in conductivity

Intermediate magnitude, high contrast in conductivity

High magnitude, high contrast in conductivity

Donna Donna

Hidalgo Hidalgo

Mission Mission La Joya La Joya La Feria La Feria

Edcouch Edcouch

Willamar Willamar

Progreso Progreso

La Leona La Leona

Harlingen Harlingen Mercedes Mercedes

Paso Real Paso Real

Southmost Southmost

Las Milpas Las Milpas La Paloma La Paloma

Palmito Hill Palmito Hill

Santa Rosa Santa Rosa

Santa Maria Santa Maria

Hawk Island Hawk Island

Willamar SW Willamar SW

San Juan SE San Juan SE

East Brownsville East Brownsville

Southmost OE E Southmost OE E

West Brownsville West Brownsville

Hidalgo CountyHidalgo County

Cameron CountyCameron County

Willacy CountyWillacy County

5.55.5

7.77.7

8.18.1

5.95.9

5.25.2

6.16.1 6.26.2

5.15.1

8.28.2

5.65.6

8.38.3

8.88.8

8.38.3

9.59.5

7.47.4

6.156.15

8.98.9

8.58.5

8.88.8

7.657.65

9.159.15

9.39.3

6.56.5

6.056.05

9.49.4

7.97.9

8.658.65

8.058.05

6.456.45

7.287.28

8.88.8

8.058.05

9.19.1

9.859.85

6.356.35

8.98.9

7.27.2

5.75.7

4.454.45

8.68.6

9.49.4

6.26.2

4.84.8

8.958.95

9.559.55

8.18.1

9.159.15

7.057.05

9.359.35

9.49.4

8.48.4

6.256.25

7.957.95

8.758.75

7.757.75

7.87.8

8.28.2

7.77.7

7.37.3

6.66.6

8.28.2

10.2510.25 8.058.05

8.68.6

9.059.05

8.58.5

9.69.6

7.87.8

9.659.65

8.858.85 8.78.7

5.955.95

8.858.85

7.97.9

9.59.5 8.98.9

8.38.3

8.358.35

7.227.22

8.58.5

6.896.89

9.29.2

9.89.8

7.957.95

8.958.95

9.29.2

9.669.66

5.45.4

8.658.65

8.758.75

6.856.85

8.058.05

9.359.35

9.19.1

8.88.8

5.655.65

9.29.2

9.59.5

10.310.3

9.459.45

9.79.7

6.76.7

9.359.35

9.49.4

10.4510.45

7.17.1

9.059.05

10.4510.45 7.67.6

9.459.45

8.158.15

10.610.6

8.38.3

6.456.45

8.358.35

5.35.3

7.87.8

6.46.4

8.658.65

7.57.5

6.056.05

8.68.6

8.558.55

6.856.85

10.4510.45

10.610.6 10.310.3

6.76.7

10.110.1

7.37.3

9.159.15

5.45.4

8.358.35

8.358.35

7.57.5

5.655.65

6.656.65

7.857.85

9.459.45

8.158.15

8.78.7

8.458.45

9.459.45 8.658.655.655.65

7.67.6

8.758.75

8.658.65

8.858.85

9.659.65

6.356.35

9.49.4

9.659.65

9.459.45

98°30'0"W

98°30'0"W

98°22'30"W

98°22'30"W

98°15'0"W

98°15'0"W

98°7'30"W

98°7'30"W

98°0'0"W

98°0'0"W

97°52'30"W

97°52'30"W

97°45'0"W

97°45'0"W

97°37'30"W

97°37'30"W

97°30'0"W

97°30'0"W

97°22'30"W

97°22'30"W

97°15'0"W

97°15'0"W

°4 5'

0" N

°4

5' 0"

N

°5

2'

"N

°5

2'

"N

°0

'0 "N

°0

'0 "N

°7

'3 0"

N

°7

'3 0"

N

°1

5' 0"

N

°1

5' 0"

N

°2

2'

"N

°2

2'

"N

°3

0' 0"

N

°3

0' 0"

N

Texas

Lower Rio Grande Valley

Overall Levee Condition

Plate 18

Condition Assessment of US International Boundary and Water Commission

Lower Rio Grande Valley Levees 1:185,000Scale =

0 5 10 15 20 25 301 2 3 4 Miles

0 10 20 30 405 Kilometers

Overall Levee Condition

Condition Assessment of US International Boundary and Water Commission Lower Rio Grande Valley Levees

* Note : Identifies a New Levee or a Levee not Maintained by the USIBWC

No Data *

Greater than 10.00

7.00 - 9.99

4.00 - 6.99

Less than 4.00

Overall Levee Condition Value Condition

Good

Acceptable

Marginal

Poor

Color

Legend

Abandoned Course/Channel

Dune Deposits

Flood Basin

Natural Levee

Point Bar

Sand

CCBB

AA

C

C

B

B

A

A

98°22'30"W

98°22'30"W

98°15'0"W

98°15'0"W

98°7'30"W

98°7'30"W

98°0'0"W

98°0'0"W

97°52'30"W

97°52'30"W

97°45'0"W

97°45'0"W

°0

'0 "N

°0

'0 "N

°7

'3 0"

N

°7

'3 0"

N

°1

5' 0"

N

°1

5' 0"

N

°2

2'

"N

°2

2'

"N

Section Locations

M -65

M -65

M -64

M -64

R -16

R -16A

H -106

A H

-106

W D

-511 W

D -511

S J02-01

S J02-01

S J15-01

S J15-01

S J15-02

S

J15-02 HWY 281HWY 281

HoloceneHolocene

River LeveeRiver Levee

Beaumont FMBeaumont FM

PleistocenePleistocene

Retamal DikeRetamal Dike

IBWC FloodwayIBWC Floodway

UndifferentiatedUndifferentiated

Pleistocene/TertiaryPleistocene/Tertiary

Distance in FeetDistance in Feet

0'0'

20'20'

40'40'

60'60'

80'80'

-80'-80'

-60'-60'

-40'-40'

-20'-20'

100'100'

120'120'

-100'-100'

BB B'B'

0'

20'

40'

60'

80'

-80'

-60'

-40'

-20'

100'

120'

-100'

0'0' 9000'9000'7500'7500'6000'6000'4500'4500'3000'3000'1500'1500' 16500'16500'15000'15000'13500'13500'12000'12000'10500'10500'

E le va tio n In

F ee t M S

L

P -3

P -3P

-4 P

-4

L-46 L-46L-49

L-49

P -87

P -87

L-115 L-115L-121

L-121

M I06-1

M I06-1

LowerLower UpperUpper

FM 106FM 106

HWY 83HWY 83

Lizze FMLizze FM

HoloceneHolocene

Beaumont FMBeaumont FM

PleistocenePleistocene

USIBWC FloodwayUSIBWC Floodway

Sardinas ResacaSardinas Resaca

UndifferentiatedUndifferentiated

Pleistocene/TertiaryPleistocene/Tertiary

Distance in FeetDistance in Feet

-40

-20

AA A'A'

-40

-20

00 900090007500750060006000450045003000300015001500 12000120001050010500

E le va tio n In

F ee t M S

L

Geologic Sections A-A' & B-B'

Condition Assessment of US International Boundary and Water Commission Lower Rio Grande Valley Levees

Geologic Sections A-A' & B-B'

Plate 19

Condition Assessment of US International Boundary

CCBB

AA

C

C

B

B

A

A

PharrPharr

OlmitoOlmito

DonnaDonna

HidalgoHidalgo

MissionMissionLa JoyaLa Joya La FeriaLa Feria

EdcouchEdcouch

WillamarWillamar

ProgresoProgreso

La LeonaLa Leona

HarlingenHarlingenMercedesMercedes

Paso RealPaso Real

SouthmostSouthmost

Las MilpasLas Milpas La PalomaLa Paloma

Palmito HillPalmito Hill

Santa RosaSanta Rosa

Santa MariaSanta Maria

Hawk IslandHawk Island

Willamar SWWillamar SW

San Juan SESan Juan SE

East BrownsvilleEast Brownsville

Southmost OE ESouthmost OE E

West BrownsvilleWest Brownsville

98°30'0"W

98°30'0"W

98°22'30"W

98°22'30"W

98°15'0"W

98°15'0"W

98°7'30"W

98°7'30"W

98°0'0"W

98°0'0"W

97°52'30"W

97°52'30"W

97°45'0"W

97°45'0"W

97°37'30"W

97°37'30"W

97°30'0"W

97°30'0"W

97°22'30"W

97°22'30"W

97°15'0"W

97°15'0"W

°4 5'

0" N

°4

5' 0"

N

°5

2'

"N

°5

2'

"N

°0

'0 "N

°0

'0 "N

°7

'3 0"

N

°7

'3 0"

N

°1

5' 0"

N

°1

5' 0"

N

°2

2'

"N

°2

2'

"N

°3

0' 0"

N

°3

0' 0"

N

Legend Artificial Fill

Abandoned Course/Channel

Dune Deposits

Sand

Interdistributary

Flood Basin

Point Bar

HWY 83HWY 83

HoloceneHolocene IBWC LeveeIBWC Levee

Rio GrandeRio Grande

Beaumont FMBeaumont FM

PleistocenePleistocene

Arroyo ColoradoArroyo Colorado

UndifferentiatedUndifferentiated

UndifferentiatedUndifferentiated

Estuarine & DeltaicEstuarine & Deltaic

IBWC North FloodwayIBWC North Floodway

Pleistocene/TertiaryPleistocene/Tertiary

A -1

A -1

J-4 J-4

A -14

A -14

A -31

A -31

E -75

E -75

E -32

E -32

E -38

E -38

E -39

E -39

E -56

E -56

J-18 J-18J-19

J-19

J-25 J-25 W

D -808

W D

-808

-20-20

-40-40

-60-60

-80-80

-100-100

-120-120

-140-140

00 900090006000600030003000 33000330003000030000270002700024000240002100021000180001800015000150001200012000

CC C'C'

-80-80

-60-60

-40-40

-20-20

-140-140

-120-120

-100-100

Distance in FeetDistance in Feet

E le va tio n In

F ee t M S

L

W D

-805 W

D -805

Section Locations

Geologic Section C-C'

Condition Assessment of US International Boundary and Water Commission Lower Rio Grande Valley Levees

Geologic Section C-C'

Plate 20

Condition Assessment of US International Boundary