The People by the River

Tuesday, February 23, 2016
Leo S. Leonhart, Ph.D., RG , Hargis + Associates Inc., Tucson, AZ

The Mojave Indians (Pipa Aha Makav aka “The People by the River”) have inhabited the Mohave Valley since “time immemorial.” Historically, their presence extended over an area straddling the Colorado River from Lake Mohave ~15 mi north of Davis Dam and south to the Needles Peaks. Now officially known by the federal government as the Fort Mojave Indian Tribe (“FMIT”), Mojaves first encountered western civilization in the 16th century, when Spanish explorers first entered the area. Today, as a result of various governmental interventions, tribal members inhabit two reservations along the river. The northernmost, FMIT Reservation, comprises a “checkerboard” of parcels in Nevada, Arizona, and California and totaling ~51 mi2. Another group of Mojaves reside on the Colorado River Indian Tribes (“CRIT”) Reservation, which, in addition to the Mojaves, comprises a federation of Chemehuevis, Hopis, and Navajos. The CRIT reservation is approximately 40 mi south of the FMIT Reservation and covers approximately 460 mi2 straddling the Colorado River in Arizona and California, below Parker Dam. As landowners along the river, both tribes hold rights to divert water in amounts established in protracted litigation before the Supreme Court (Arizona v. California, 1963, et seq.). Presently, FMIT holds rights to an annual allocation of 132,789 AF, and the CRIT to a diversion of 719,248 AF, representing more than 30% of Arizona’s allocation.

This paper addresses the FMIT’s water resource challenges, including issues related to both water supply and water quality. For the FMIT, the latter issue arises as a result of ongoing actions to remedy a groundwater plume of hexavalent chromium from the Topock Compressor Station, south of the FMIT Reservation and on grounds highly sacred to the Mojaves. This matter has created profound conflicts between the need to preserve traditional tribal values and to remedy a serious environmental threat.

Leo S. Leonhart, Ph.D., RG, Hargis + Associates Inc., Tucson, AZ
Leo Leonhart received his bachelor’s in geology from Youngstown State University, a master’s in water resources from Ohio State University, and his doctorate in watershed hydrology from the University of Arizona. He is a registered geologist and certified hydrogeologist, practicing as Principal Hydrogeologist at Hargis + Associates in Tucson. He is adjunct faculty at the Department of Hydrology and Water Resources at the University of Arizona and the University of Phoenix. His professional experience spans over four decades in hydrogeologic investigation, and he has been project director of the Apache Powder Superfund project for most of its lifetime.