Groundwater‐Surface‐Water Interactions in the Grand Canyon National Park

Author
Gus Tolley

Abstract

A growing number of visitors to the Grand Canyon National Park and population increases around the park have resulted in greater demand on water resources in the region. Surface‐ water rights are already over‐allocated for the Colorado River, and pumping thousands of feet from the bottom of the Grand Canyon is costly. As a result, many people look to groundwater to meet this increased demand. While land within the park boundary is protected from development, groundwater pumping from wells outside the park can significantly affect stream and springflow within the park. This is due to the large lateral extent of the major aquifer systems in the region and the connection between surface‐water and groundwater. Although springs account for only a fraction of the landscape within the Grand Canyon, they represent vital habitat for many species found within the park. In addition to the ecological function springs serve, they also have aesthetic, economic, and cultural importance for both park visitors and Native American tribes living in the area. Increased groundwater pumping from the major aquifer systems found near the Grand Canyon can decrease carrying capacity of springs, change flow from perennial to ephemeral or even dry up springs entirely. Therefore, any proposed development of groundwater resources in the area should be carefully considered.