Rio Bravo River (Mexico) Emergency Drought Plan

Introduction

The purpose of this project is to assist Mexico in creating an emergency drought plan for the Rio Bravo River Basin.  Mexico is currently experiencing one of the most severe and extended droughts on record in this region, with river flows well below historical average and dam storages on the Rio Bravo at their lowest since first filled.  This extreme lack of water has meant a reduction or elimination of water for irrigation districts, difficulty in providing adequate municipal water, and limited ability to meet international water agreements.  The severe drought has prompted Mexico to undergo a planning process for an emergency drought plan for the Rio Bravo River Basin with the assistance of the University of Washington.  The university is currently working with the Comision Nacional del Agua, the Mexican Institute for Water Technology, and the International Boundary and Water Commission, with intention to involve local stakeholders.  During the process the group will identify problems, develop goals, objectives, and metrics for the plan, assemble data and analysis tools, and identify and evaluate a wide range of plans.  A Shared Vision Model of the river basin system will provide an opportunity to make water management decisions based on the entire basin in order to best serve the whole region. 

Overview
During recent years, the Rio Bravo (Rio Grande) has suffered one of the most severe and extended droughts in its recorded history.  Thus far in 2001, conditions have only worsened.   The natural runoff of the six rivers considered in the 1944 International Waters Agreement belonging to Mexico have been only

11% of the historical average during the period of January to July of 2001, representing the lowest flows during the dry period that began in 1993.    

In response to this drought, the Mexican government has declared 19 northern states disaster areas. During 2001, Mexico has limited the amount of water provided to the irrigation districts in the basin in attempts to better manage the water that is available.  Access to stored water has been limited, with some irrigation districts receiving no water, and others receiving considerably less than they have in the past.  Deliveries to the Delicias, Rio Florido, Bajo Rio Chonchos, Don Martin, and Bajo Rio Bravo districts have been reduced to 28% of typical water delivers prior to 1992, and to 40% of what they had been in the period of 1993-2000.  This extended period of low flow has had significant impacts on the ability to provide water in the region.  Two major reservoirs, the Falcon Dam (completed in 1954) and the Amistad Dam (completed in 1969) have been particularly impacted.  These two reservoirs, that are located on the main stem of the Rio Bravo and designed to supply water for both municipal and agricultural uses, are extremely low.  They have, in fact, reached their lowest storage values since having been initially filled.   Figure 1 presents the storages in the reservoirs since 1996.

Since 1996, when the relative storage of the US and Mexico portions of capacity were 18 and 47% of the full conservation pool in the combined Amistad and Falcon reservoirs respectively, Mexico's storages have steadily declined while the US storage increased until January of 2001 and then began to decline.

Currently the US and Mexico have approximately 265 and 30 million cubic meters of water remaining in the conservation pool at Falcon, and 307 and 37 million cubic meters of water remaining at Armistad, respectively.  This has left Mexico with a serious deficit in the amount of water that it has available, creating difficulties in providing water to irrigators and municipalities.  In addition, it has created challenges in allowing Mexico to meet its international water agreements.

This drought has encouraged the water resource planners and managers in Mexico to embark on an emergency drought planning process for the Rio Bravo.  In this effort, the Mexican is working with the University of Washington to develop emergency drought management plans for the Rio Bravo River.

Work Plan

Dr. Richard N. Palmer with work with staff members of the Comision Nacional del Agua, the International Boundary and Water Commission, and the Mexican Institute for Water Technology to develop an emergency drought plan for managing drought in the Rio Bravo basin.  Dr. Palmer with provide expertise and guidance to help these parties manage the current drought and to develop drought plans for other river basins in Mexico.

Four specific tasks will be performed.  These include the following:

1. Identify the most important problems caused by the current drought,
2. Develop goals, objectives, and metrics for the emergency drought plan,
3. Assemble the data and analysis tools necessary to evaluate the effectiveness of emergency drought plans, and
4. Identify and evaluate a range of emergency drought plans.

Updated 05/13/2005