Delineation of Recharge Areas, Groundwater Flow Pathways, and Travel Times on the Kaibab Plateau, Arizona

Roaring Springs is the sole supply of potable water to the 4.4 million annual visitors and employees at Grand Canyon National Park. Roaring Springs and other karst-fed springs on the Grand Canyon's North Rim also provide baseflow to the Colorado River and support riparian habitats along tributary canyons. Climate change and proposed use of the land north of Grand Canyon National Park may dramatically affect the quantity and quality of water discharging from the North Rim springs. Grand Canyon National Park needs a better understanding of the karst systems on the North Rim and groundwater flowpaths to Roaring Springs and others.

Fieldwork for this study occurred between July 2007 and July 2008. Flow data for Roaring Springs (above and below the springs), Bright Angel Creek, Emmett Springs, Angel Springs and Phantom Creek were collected and analyzed with other limited historical data. Water samples from all of the flow measurement locations in addition to both Monsoon and winter precipitation samples from the North Rim were analyzed for 18Oxygen and 2Hydrogen concentrations and were interpreted relative to global and local meteoritic water lines. Detailed analyses of major cation/anion data will be presented. A conceptual triple-porosity numerical groundwater flow model of the hydrogeologic system connecting the Kaibab Plateau to North Rim springs will be presented, incorporating all these new data.