Examining virtually unexplored territory of the Rio Grande
By April Smith
The Rio Grande contains a 200-mile stretch of river that flows from El Paso-Juarez to its confluence with the Rio Conchos at Presidio-Ojinaga called the “Forgotten River.” This name is due to the lack of scientific data available and the absence of cities along its path.
During the last few decades, many people have immigrated to the Forgotten River stretch leading to substantial population and industry growth in the cities. Consequently, water quality in and downstream of El Paso-Juarez has been declining because of effluent discharge from product assembly plants, irrigation return flow, raw municipal effluent from Mexico, and treated effluent from El Paso.
Because the Forgotten River flows undisturbed for such a long distance, receiving no municipal or industrial effluent and having no perennial streams, it is an exceptional and potentially valuable natural laboratory. Its value as a natural laboratory is that it can be used to study the ability of a desert river to “treat” or “assimilate” contaminants that have been produced by municipalities.
Catalina Ordonez, a doctorate student at the University of Texas-El Paso, hopes to find out more about the Forgotten River by conducting research in five sites along its 200-mile stretch from Fort Quitman to Presidio. She is focusing on the impact of heavy metals on the river and its biology. Metals are good indicators of the level of contamination being retained throughout the segment’s length as heavy metals do not decompose but rather can be absorbed by plants or adsorbed by minerals.
In each of the five testing sites, Ordonez collected quarterly samples of water, sediment, fish and macroinvertebrates. She will continue to conduct sampling in each season throughout the next year. This allows her to obtain samples that reflect changes in the river throughout the year.
In addition to testing heavy metal levels, Ordonez tests chemical parameters in water and sediment, such as dissolved oxygen, salinity, conductivity and temperature. These results will reveal the river’s ability to support biodiversity, a good indicator of the river’s health.
Because there has been very little research performed in the Forgotten River stretch, Ordonez hopes to provide baseline data that identifies the river’s existing conditions. “We all depend on the river, and it will disappear if we don’t take care of it,” she said.
Ordonez received a grant from the Texas Water Resources Institute, to support sampling activities related to her research project.
