The Characteristics and Importance of Temporary Streams

In the Piedmont region of the eastern United States, much of the historical agriculture, 20th-century afforestation, and widespread residential development have occurred within watersheds dominated by temporary (i.e., ephemeral and intermittent) stream networks. However, increasing water quantity and quality demands have outpaced the basic understanding of these systems and their sensitivity to environmental change. Where, when, and how temporary streams flow, as well as their connection to below-ground aquifers, is poorly understood. To address this knowledge gap, Maggie Zimmer and colleagues utilized an ephemeral-to-perennial drainage network in the Piedmont region of North Carolina to gain new understanding about the drivers of streamflow generation, stream-groundwater interactions, and the expansion/contraction of the stream network. Through their results, they show that internal watershed dynamics that produce temporary streams play a central role in biogeochemical fluxes and groundwater recharge at the watershed scale.