Streaming potential and seepage meter studies at Upper Lake Mary near Flagstaff, Arizona

Abstract

Upper Lake Mary provides approximately 75% of the water for Flagstaff, Arizona. Water budget studies by the U.S. Geological Survey indicated that 42% of lake inflow is lost to leakage through alluvium, fractured volcanics and the underlying Kaibab limestone. The hypothesis that the majority of leakage is occurring above fractures was tested. A one dimensional, linear relationship between streaming potentials and seepage rates was developed. Streaming potential and seepage meter surveys were performed in an area near the dam. The developed relationship was then used to convert streaming potential measurements to seepage rates. Results show that leakage is 2.3 times greater than the lake average above fractures. However, the total volume of this preferred leakage is not significant in comparison to total leakage from the lake.