Des Moines Water Works (DMWW) is a regional municipal water utility that supplies residential and commercial water resources to about 600,000 customers in Des Moines, Iowa, and surrounding municipalities in central Iowa. DMWW has identified a need for increased water supply and is exploring the potential for expanding groundwater production capabilities in the Des Moines River alluvial aquifer, where it operates two radial collector wells (RCWs). The U.S. Geological Survey, in cooperation with DMWW, completed a study of the Des Moines River alluvial aquifer and the interactions of the RCWs with the aquifer; no previously published model has included the existing well locations, which is the focus of this model. A numerical groundwater flow model has been developed to characterize the Des Moines River alluvial aquifer based on a conceptual model under historical conditions, to simulate water levels observed in the DMWW RCWs, and to provide a tool that potentially can be used in the future to evaluate groundwater production scenarios. The data release directories contain ancillary, bin, georef, model, output, and source folders for the following model: tr_mf6_sim: A calibrated transient MODFLOW 6 groundwater flow model of the Des Moines River alluvial aquifer near Des Moines, Iowa.