Erika studied the rate of groundwater seepage into the river.  Using the simple fact that, in summer, groundwater is substantially cooler than the river water, she was able to locate areas of cool reaches of the river where high rates of recharge occur.  Detailed mapping of sediment temperatures in these zones showed that the discharge is focused to a few places in these zones; see the map below.  Work continues to identify the cause of this focused discharge.  

Erika's work illustrates the fact that groundwater and surface water should be considered a single resource.  Future studies can map more of the river with the same techniques, and investigate the chemical and biological implications of the focused discharge.

A portion of a map showing sediment temperatures, contoured in degrees centigrade.