Date of Award:


Document Type:


Degree Name:

Master of Science (MS)


Civil and Environmental Engineering

Committee Chair(s)

Belize A. Lane


Belize A. Lane


David E. Rosenberg


Sarah E. Null


Environmental flows are used to maintain streamflow for aquatic species in rivers while also sustaining human water requirements. While there are many approaches to develop environmental flows, they all rely on a strong conceptual understanding of flow-ecology relationships, which are often uncertain. Uncertainty in flow-ecology relationships can stem from using limited data to develop or test relationships or an incomplete understanding of the attributes inherent to each relationship, such as climate and land conditions. Accounting for these attributes and uncertainty in flow-ecology relationships is critical given mounting interest to develop and implement environmental flows at large scales, often with limited information. Using the South Fork Eel River watershed in northern California USA as a case study, I explored attributes and uncertainty in flow-ecology relationships through a targeted review of academic journal articles and Bayesian Network modeling. I found that few relationships describe explicit links between the flow regime and species or cover the full range of climate and land conditions present in the watershed. These gaps informed several scenarios within a Bayesian Network model—represented as different sets of probabilities—which show that model results can differ by up to 50% depending on the uncertainty scenario. This study informs future field monitoring efforts to develop flow-ecology relationships and promotes effective translation and modeling of existing flow-ecology relationships and their uncertainties.