Restoration of an International River Basin

The Rio Grande River flows from its headwaters in southern Colorado, south through New Mexico, turning southeast at El Paso, Texas, where it becomes the international boundary between the United States and Mexico until it drains into the Gulf of Mexico. The Rio Grande is a “National Historic River.” The Rio Grande is managed according to interstate and international agreements that apportion its water through the operation of reservoirs and diversion systems. Downstream of Elephant Butte Reservoir, New Mexico the waters of the Rio Grande are used primarily by irrigators on both sides of the border. The City of El Paso, however, under contractual agreements with the local irrigation districts treats Rio Grande water to supplement the city’s drinking water supply. This paper provides an overview of the hydrologic challenges of making the Rio Grande “wet” once again through the El Paso-Ciudad Juarez region on the U.S.-Mexico border. Currently water is released downstream only during the irrigation season, which during normal-flow years extends from late February to early October. Every aspect of water delivery in the stretch of the Rio Grande from Elephant Butte Reservoir and El Paso, Texas is managed through the use of engineering structures that divert water for irrigation or municipal uses. In the past 100 years, the response to declining flow within the actual river has turned a once meandering stream to an efficient conveyance channel. The historical water flow and water quality data recorded at various gauging locations downstream of the Elephant Reservoir to Fort Quitman, Texas are reviewed and analyzed to determine the impacts and structure of the existing delivery system. Key issues discussed include the implications to the efficiency of water delivery, flood control, sedimentation buildup in the river channel, and water quality. An extensive literature review of hydrological data, field visits, and interviews with local stakeholders is being conducted to evaluate the current structure. The main objective of this work is the development and assessment of scenarios that would allow the river to remain “wet” through the year in the El Paso, Texas and Ciudad Juarez, Mexico portion of the Rio Grande while minimizing the impact to the existing water delivery structure. A review and analysis of hydrological data will help to demonstrate potential long-term consequences of water development in other rivers