Nonhuman Animals, Human-Created Environments

Cienega_de_santa_claraKarl Coplan

Sunday’s New York Times article about the threat to the La Cienega marsh on the Mexico-US border raises interesting questions about human responsibilities to maintain human-created environments that have been occupied by natural species.  The La Cienega marsh was created by the diversion of Arizona agricultural runoff too high in salt content to be returned to the Colorado River for downstream use.  While the federal government built a desalination plant nearly two decades ago for the purpose of purifying the runoff sufficiently to return it to the Colorado, this plant has never been operable due to technical and budgetary issues, and instead, the salty runoff was diverted through a series of pipes and channels to the Sonoran desert in Mexico.  Fed by this artificial diversion, a saltwater marshland sprang up, and populated itself with Thule grass, pelicans, and endangered Yuma Clapper Rail and Desert Pupfish.

Now, the federal government is planning to activate the desalination plant to recover the saline runoff.  The desal plant will discharge into the Colorado River, satisfying US treaty obligations to maintain Colorado River flow to Mexico, and freeing up more Colorado River water for upstream domestic and agricultural use by thirsty human activities in the Southwest.  The problem is that once the saline runoff is intercepted by the desal plant, the water source for La Cienega will dry up, the thriving wetlands will stop being wet, and the endangered species habitat will disappear.  Remarkably, the environmental impact studies for the desal plant did not consider these impacts on La Cienega. Continue reading