This video shows the annual spatial impact of the Maumee River into Lake Erie. Our manuscripts describes how we tracked the plume of Maumee total phosphorus (TP) impact using grab samples in Lake Eire. This was not previously possible because of the distances between sampling locations and the fact that the number of unobserved days outnumber the observed days. Importantly, this is not a plume that displays high concentration of TP, rather this is the impact plume of the Maumee River. Concentrations outside the impact plume are not influenced, or are weakly influenced, by the Maumee River and thus load reductions within the Maumee River would not impact lake concentrations in those areas.