Three regression models were developed for describing variability of host-specific flux data in eight Great Lakes tributaries. Models include one for Lachnospiraceae flux, one for human bacteroides flux, and one for ruminant bacteroides flux. Models were developed using the R project for statistical computing with core functionality and the survival, smwrBase, and smwrQW packages. Predictor variables for these models are included in the data file and input files provided. These include sampling dates and times, rainfall depth, percent of watershed underlain by tile drainage, cattle population (for the ruminant marker model) and human population (for the human marker models). Sample collection and laboratory analyses methods are fully described in the associated journal paper (https://doi.org/10.1021/acs.est.8b01945).