The McDonnell lab focuses on measuring, modeling, and understanding watershed-scale water cycling.

From its first 20 years, the group focused on streamflow generation and the age, origin, and pathway of storm runoff. Understanding watershed storage and release was the overarching research goal. Most of the group's early work focused on hydrograph separation, streamwater transit time analysis and deciphering runoff mechanisms across diverse catchments.

For the past 10 years, the group has begun to broaden its aims by going after questions of how geology and biology affect the amount and age of water in streams and how isotope tracers can help answer these questions.

Our goal for the next 10 years is the development of an age-based theory of the catchment water cycle to complement and extend the traditional water balance. Read our lab vision Here.