**INTERNA**

**TIONAL B**  **OUNDAR**

**Y A ND**  **WA**

**TER COMMISSION, UNITED ST** 

**AT ES**  **AND MEXICO**

Carlos Marin, United States Commissioner Presentation to the Good Neighbor Environmental Board

July 24, 2007

# MISSION OF THE COMMISSION The International Boundary and W ater Commission is responsible for applying the boundary and water treaties between the United States and Mexico and settling differences that arise in their application.**STRUCTURE PER 1944 TREA**  **TY INTERNA** 

**TIONAL B**  **OUNDAR**

**Y AND**  **WA**

**TER COMMISSION (IBWC)**  **MEXICAN SECTION** 

• Mexican Commissioner

• Secretary

• Two Principal Engineers

• Legal Adviser **US SECTION** 

• US Commissioner

• Secretary

• Two Principal Engineers

• Legal Adviser

# IBWC STRUCTURE
 

## Commission has the character of an international organization for joint projects  

## Decisions of the Commission are recorded in the form of Minutes approved by the two governments.  

## 312 Minutes

# IBWC FLOOD **CONTROL PROJECTS**   

## Lower Rio Grande  

## Presidio, TX  

## Rectification Project – El Paso- Cd. Juarez  

## Chamizal Project – El Paso- Cd. Juarez  

## Canalization Project – Las Cruces - El Paso  

## Colorado River – near Yuma - Mexicali  

## Tijuana River – San Diego-Tijuana

# FLOOD CONTROL **TERMINOLOGY**
 

### Levee – en elevated earthen berm parallel to the river channel that protects adjacent property from floodwaters  

### Freeboard – a term that reflects the distance from the water surface elevation to the top of the levee  

### Overtopping – where floodwaters rise above the top of the levee  

### Interior Floodway – a separate channel off the main river channel where floodwaters can be diverted to reduce flood flows in the river

# FLOOD CONTROL**T ERMINOLOGY** 

**U.S. Lev ee**  **Mx Lev ee**  **Low F**  **low C**  **hannel**

# LOWER RIO GRANDE FLOOD **CONTROL PROJECT**  

## History  

### Hidalgo and Cameron Counties coordinated with Mexico in 1920s for Rio Grande levees and floodways  

### IBWC developed and implemented a new plan in the 1930s  

### Additional improvements made in 1950s  

### Covers 180 river miles from Peñitas, TX to Gulf of Mexico

# LOWER RIO GRANDE FLOOD **CONTROL PROJECT**  

## Hurricane Beulah (1967)  

### Category 3 storm at Brownsville  

### 35 inches of rain caused widespread flooding in Texas and Mexico  

### Flow of 220,000 cfs at Rio Grande City  

### Over $1 billion in damage, 58 deaths  

### Flooded McAllen Airport, Harlingen, Cd. Mier, Cd. Camargo, agricultural landsHarlingen, Texas 1967Raymondville, Texas 1967

# LOWER RIO GRANDE FLOOD **CONTROL PROJECT**  

## Minute 238 (1970)  IBWC agreement to upgrade the Lower Rio Grande Flood Control Project  U.S. and Mexico agreed to a design flood of 250,000 cfs at Rio Grande City, TX- Cd. Camargo, Tamaulipas  Some elements constructed jointly; others undertaken by each country  Both countries share flood risks and benefits of flood control infrastructure

# LOWER RIO GRANDE FLOOD **CONTROL PROJECT**  

## U.S. Infrastructure  

### 270 miles of levees  

### Thousands of acres of interior floodway  

### Weirs  

### 420 drain structures  

### 180 irrigation structures  

### 10 bridges  

### Provides flood protection for hundreds of thousands of U.S. residents

# LOWER RIO GRANDE FLOOD **CONTROL PROJECT**  

## Anzalduas **Dam**  

### Built and operated jointly by U.S. and Mexico  

### Located near McAllen, TX – Reynosa, Tamps.  

### Diverts U.S. share of floodwaters to U.S. interior floodway  

### Diverts irrigation water for Mexico

# ANZALDUAS **DAM**

# LOWER RIO GRANDE FLOOD **CONTROL PROJECT**  

## Retamal Dam  

### Built and operated jointly by U.S. and Mexico  

### Built to limit flood flows at Brownsville, TXMatamoros, Tamps.  

### Diversion of Mexico’s share of floodwaters to its interior floodway

# RET

**AMAL DAM** **Main Floodw** **ay North**  **Floodw ay** 

**An zalduas**  **Dam Retamal**  **Dam Ar** **roy o**  **Colorado**

**McA llen**  **Harlingen**

**Brow nsv** **ille**

# FLOOD WORKSHOPS

 

### Binational workshops held annually  

### Participation of field office and Headquarters staff from both Sections, National Weather Service, Conagua  

### Flood Operations Manual reviewed for Amistad, Falcon, Anzalduas, Retamal Dams  

### Flood scenarios are developed and binational planning exercises are conducted  

### Ensures preparation for joint operation of dams during flood events

## ENVIRONMENTAL CONSIDERATIONS

 USIBWC has reduced floodway mowing in the Lower Rio Grande to help establish a wildlife corridor, per 1993 U.S. Fish and Wildlife Service Biological Opinion  Purchase of conservation easements underway to expand wildlife corridor  Cameron County, river mile 28 to 62.5  Easements to provide 33 ft. vegetated corridor next to 75 ft. cleared bank  13 tracts to be acquired by end of the year. 200 - 300 tracts sought.  Tree planting in Canalization Project  EIS and stakeholder collaborative process underway in Canalization Project considers environmental enhancements and flood control improvements

# FEMA CONSIDERATIONS  

### FEMA is updating flood maps in targeted counties nationwide  

### Maps will determine mandatory flood insurance requirements  

### FEMA requires certification that levees can withstand the 100 -year flood with 3 feet of freeboard  

### USIBWC has informed FEMA that it cannot certify levees in Doña Ana County, NM and El Paso, Hidalgo, and Cameron Counties, TX

# LEVEE DEFICIENCIES  

### USIBWC levees were constructed decades ago; with time, they have degraded  

### In some areas, levees are no longer high enough to contain the design flood  

### Lower Rio Grande Flood Control Project  U.S. levee overtopping for 38 river miles (up to 6 ft), freeboard encroachment for 64 river miles  U.S. floodway overtopping for 2 miles and freeboard encroachment for 24 miles  Mexican levee overtopping for 57 river miles and freeboard encroachment for 110 river miles

# LEVEE DEFICIENCIES

 Doña Ana County, NM – 1 mile overtopping, 37 miles freeboard encroachment  El Paso County, TX – 2 miles of overtopping, 24 miles of freeboard encroachment  Levees within inches of overtopping in El Paso in 2006 Rio Grande at El Paso, 8/1/06

# LEVEE IMPROVEMENT PLAN  

### Lower Rio Grande  $125 million estimated cost  Annual budget typically $2
–5 million  Work undertaken as funding becomes available  MOU for Hidalgo County to use bond funds to raise a critical 12 - mile reach near Mission  

### El Paso County  $20 million estimated cost  USIBWC in 2007 raised 7.4 miles of levee in east-central El Paso  Additional funds required for sediment removal - $650,000 acquired by Congressman Reyes in current FY

# LEVEE IMPROVEMENT PLAN

 

### Doña Ana County  $20 million estimated cost  Sediment removal at key areas is performed as part of annual Operations and Maintenance  

### Coordination with Mexico  Data sharing and cooperation on hydraulic modeling  Each country required to maintain its own levee system to the agreed - upon design flood  Joint Report of the Principal Engineers for improvements in the El Paso-Juarez area

## INTERNATIONAL STORAGE DAMS  

### Amistad Dam, Del Rio, TX

– Cd. Acuña, Coah.  Flood control, water storage, recreation, hydro power  Total capacity 4.9 maf (including flood storage) Amistad Dam  

### Falcon Dam, Falcon Heights, TX – Nueva Cd. Guerrero, Ta mps.  Flood control, water storage, recreation, hydro power  Total capacity 3.16 maf (including flood storage)  Provides water and flood control for Lower Rio Grande

# DAM **SAFETY**

 

### Routine dam safety inspection done in 2007  

### Conducted by IBWC and technical advisors from U.S. Army Corps of Engineers and Conagua  

### Dams are ranked per Corps of Engineers Dam Safety Action Classes:  DSAC I – Urgent and Compelling (unsafe)  DSAC II – Urgent (potentially unsafe)  DSAC III – High Priority (conditionally unsafe)  DSAC IV – Priority (marginally safe)  DSAC V – Normal (safe)

# DAM **SAFETY**
 Report found all dams to be generally well - maintained and able to operate under normal conditions  Amistad Dam  DSAC II – Urgent (potentially unsafe)  Concerns about impact of naturally-occurring sinkholes  Report recommends that a panel of geotechnical consultants be convened starting in the next funding request cycle  Falcon Dam  DSAC III – High Priority (conditionally unsafe)  Concern about foundation seepage  Report recommends a comprehensive seepage analysis and evaluation of dam stability using current analytical methods to confirm or change the DSAC

# DAM **SAFETY**  

### Anzalduas Dam  DSAC IV – Priority (marginally safe)  Report recommends that IBWC continue to update electrical and mechanical systems, remove sediment near the dam  

### Retamal Dam  DSAC III – High Priority (conditionally unsafe)  Concern about central gate oscillation during floods  Recommends modifying flood operations to reduce use of central gate and replacing the gate lifting system

# RECOMMENDATIONS

 

### Encourage FEMA to give time for certain levee improvements to be completed before Flood Insurance Rate Maps are finalized  

### Support development and use of more sophisticated modeling by FEMA and others to more accurately map flood risk  

### Encourage local, state, and federal cooperation on flood control issues  

### Support technical assistance to Mexico for needed flood control improvements**INTERNA**

**TIONAL B**  **OUNDAR**

**Y A ND**  **WA**

**TER COMMISSION, UNITED ST** 

**AT ES**  **AND MEXICO**

U.S. Section (915) 832 -4100 www.ibwc.state.gov