HYDROGEOLOGY OF NAVAJO MOUNTAIN, UTAH AND THE NAVAJO MOUNTAIN WATER SUPPLY PROJECT

Navajo Mountain is a laccothic dome formed by the intrusion of igneous rock. The ground water at Navajo Mountain is located within the Kaiparowits hydrologic basin. Regional groundwater flow is to the northeast toward Lake Powell. However, this regional flow pattern is modified in the Navajo Mountain area by the intrusive domal structure of Navajo Mountain. The communities at Navajo Mountain straddle the Arizona and Utah border east of Page, Arizona and are mostly within San Juan County, Utah. The communities are also within Navajo Mountain Chapter of the Navajo Nation. The only access road to Navajo Mountain is on Navajo Route 16. In addition to the Navajo Mountain springs and Lake Powell, there are aquifers in the region that have been the focus of exploration to supply Navajo Mountain communities with additional water. The major aquifers in the region in descending order are the shallow alluvial aquifer, the N-aquifer (Page/Navajo/Wingate sandstones) and the C-aquifer (Coconino/DeChelly sandstones). Results of test wells and technical reports by the Navajo Nation Department of Water Resources and federal agencies over the past decade have confirmed that water needs to be imported to meet future water demands. The Navajo Mountain alluvial wells and springs were affected by the 2002 drought. As a result, many residents were forced to drive 150 miles, round-trip, to haul water from Black Mesa Mine. In 2003, the Intergovernmental Relations Committee of the Navajo Nation Council passed Resolution IGRMA-58-03 which approved a “Strategy to Meet the Urgent Need for a Reliable Community Water Supply and Access Road for the Navajo Mountain Chapter.” This resolution supported importation water from a portion of the N-aquifer approximately 25 miles south of Navajo Mountain. Over the last several years, the Navajo Mountain Water Supply Project was divided into multiple stand-alone phases based on funding. In the fall of 2006, the Navajo Nation Council provided several million dollars in funding from its general funds for the final phase of the project. This project is one example of the hydrogeological, technical, political, legal and fiscal challenges facing Navajo Nation water development.