In support of a preliminary analysis performed by New York State Department of Environmental Conservation (NYSDEC) that found elevated nutrient levels along selected reaches of the Mohawk River, one-dimensional, unsteady, hydraulic and water-quality models using HEC-RAS and HEC-RAS Nutrient Simulation Module I (version 5.0.3) were developed by the U.S. Geological Survey (USGS) for the 127-mile reach of the Mohawk River between Rome and Cohoes, New York. The models were designed to accurately simulate within-channel flow conditions for this highly regulated, control structure dense river reach. The models were calibrated for the study period of May through September 2016 using best available streamflow, temperature, and water quality data. Nitrogen, phosphorus, dissolved oxygen, and water column algae were balanced within the models with a focus on phosphorus. Nine phosphorus reduction scenarios were implemented, applying the reductions to wastewater treatment plant (WWTP) effluent concentrations within the models. Monthly mean differences were computed at five comparison locations. Scenario results were generally linear and predictable with scenarios with the greatest reductions in phosphorus concentrations corresponding to larger differences in Mohawk River phosphorus concentrations downstream of the WWTPs associated with those reductions. The contents of this data release support the following publication: Suro, T.P., Niemoczynski, M.J., and Boetsma, A.C., 2024, Development and calibration of HEC-RAS hydraulic. temperature, and nutrient models for the Mohawk River, New York: U.S. Geological Survey Scientific Investigations Report 2024-5005, https://doi.org/10.3133/sir20245005.