Water challenges arising out of the historical allocation of the water of the Rio Grande /Rio Bravo in El Paso -Juarez region
There are to objectives of this research. The first one is to review the basis for the water allocations between the valleys of El Paso, Texas and Juarez, Chihuahua set out in the Treaty of 1906. This agreement has not yet been critically examined from a Mexican perspective, nor has its subsequent impact on U.S.-Mexico water negotiations been fully explored. This study investigates the background of water allocation under the Rio Grande Project, which is an agreement between the states of New Mexico and Texas concerning the use of water from the Rio Grande and its tributaries, in the section beginning at San Marcial, New Mexico to Fort Quitman, Texas. The research focused on the water challenges arising out of this distribution in El Paso Juarez region (Treaty of 1906) with emphasis on the Juarez Valley. The second objective is to evaluate the subsequent economic impact of water salinization and its effects on agricultural production in the Juarez Valley due to the unfavorable water distribution in El Paso-Juarez region.^ For the first objectives, two scenarios were examined associated with the water distribution between the U.S. and Mexico in 1906 and the water debt from Mexico to the U.S. at the beginning of this decade. The first scenario is a hypothetical comparison considering 2/9 of the U.S. water volume from the Elephant Butte Dam to Mexico (the same water volume criteria as in the treaty of 1944). In this scenario the water volumes of the EBID and EPCWID #1 are added; 22,361 Mm3 (18.13 Maf) + 14,717 Mm3 (11.93 Maf) = 37,078 Mm3 (30.06 Maf); 37,078 Mm3; 30.06 Maf * 2/9 = 6.68 Maf (8,239 Mm3); 8,239 Mm3 divide by 46 years, which is the period of study (1936-1995) = 179.1 Mm 3 (0.145 Maf), which is almost the water used per year by the Juarez Valley since 1936. With the 2/9 of the water from the U.S. Mexico would not have needed to use wastewater and groundwater with the subsequent environmental benefit for river. While Mexico gave to the U.S. 33% (1/3) of its water in the Lower Rio Grande/Rio Bravo (2/9 of the total amount of water in this part of the river), Mexico received only 0.2% of water from the river in Ciudad Juarez.^ The second scenario is a hypothetical comparison considering an equitable share of water among the surface water users. This scenario divided the water proportionally to the land watered by each irrigation district. The allotments for EPCWID and HCCRD of 7.32 Maf (9,072.73 Mm3), and 3.94 Maf (4,863.9 Mm3), respectively are very high regarding the efficient volumes 2.86 Maf (3,523.2 Mm3) that they should have used for irrigation. The water surplus, 5,504.52 Mm3, should be divided between two countries proportionally to the surface water users. It gives 1.3 Maf (1,603.5 Mm3) for Mexico, almost the same as the water debt from this country to the U.S. in the water conflict 1999-2002 = 1.5 M-af (1,850 Mm3).^ For the second objective, this thesis quantifies the economic impact on the Juarez Valley resulting from the 1906 distribution of water, and subsequent agricultural salinization. Agricultural damages due to salinization in the Juarez Valley (considering salinity from the Rio Grande/Rio Bravo water in the period 1999-2001) reached $881,832 U.S. dollars for alfalfa. The damages considering groundwater reach $4,761,894 U.S. dollars for alfalfa. Finally, the damages considering wastewater reach $7,231,024 U.S. dollars for alfalfa. In this period the relative yield loses for alfalfa and wheat was 41% and 8% due to use of wastewater. Because of the use of groundwater, loses were 27% and 3% respectively. The impact on crop yield due to the use of surface water was not relevant although from 1936 to 1995 the TDS concentration (822 ppm) in average was above the standard of 700 ppm.^ A historical analysis of the distribution of Rio Grande/Rio Bravo water in the El Paso-Juarez region is carried out in the literature review. Research on the economic impact of salinization is completed based on salt concentrations from groundwater and wastewater in the Juarez region, as well as data from the U.S. bureau of Reclamation. This dam is significant, as it is the diversion point from the Rio Grande/Rio Bravo into the Acequia Madre, which supplies water to Ciudad Juarez, and irrigation water to the Juarez Valley. For this part of the study, a mathematical model developed by Maas and Grattan (1999) using EXTEND software is utilized.^ Research was based on data provided by the United States Bureau of Reclamation (U.S.B.R.); The Secretaría de Agricultura, Ganadería, Desarrollo Rural, Pesca y Alimentación (SAGARPA) in Chihuahua, Mexico; and the National Water Commission (CNA) in Ciudad Juarez. Using this data, the model by Maas and Grattan is applied in order to examine crop yield reductions attributable to salinity.^ Based on the economic analysis performed in this dissertation, the United States should provide economic support to the Juarez Valley as compensation for imbalances in river water distribution since 1916 after the Elephant Butte dam was built. Additionally, a binational Rio Grande/Rio Bravo Project Economic Development Council should be created for the El Paso-Ciudad Juarez region to address remediation and promote an equitable distribution of water in the future.^
Environmental Sciences|Engineering, Environmental
Salas-Plata, Jorge A, "Water challenges arising out of the historical allocation of the water of the Rio Grande /Rio Bravo in El Paso -Juarez region" (2005). ETD Collection for University of Texas, El Paso. AAI3249245.