This dataset provides detailed information on availability of model resources (including models and datasets) that support the modeling of six key water-quality constituents (or constituent categories) across the hydrologic system. In addition, resources associated with nine “cross-cutting” topics for modeling water quality are included, with “cross-cutting” defined herein as having relevance to more than one constituent. The model and data resources were generated as a companion product to a related publication (Lucas and others, 2025) that identifies gaps in water-quality modeling capabilities needed for assessments, projections, and evaluation of management alternatives to support ecosystem health and human beneficial use of water resources. Multiple spreadsheet tables include modeling resources for contemporary and representative models that represent an extensive but not exhaustive list; the models or datasets within each worksheet are presented in terms of the model or data source type, relevant hydrologic compartment(s), and software availability (defined at the bottom of each worksheet). Models originating in government, academia, non-governmental organizations, and private industry were considered. We emphasize models that are widely used, open source, and representative of the state of the art; additionally, models were included that are published in the literature and (or) for which documentation is easily available on the internet. This data release includes the metadata and the modeling capabilities workbook, “WQ_Models_Tables_1-14.xlsx” that includes a cross-cutting topics overview tab and the following cross-cutting topics worksheets: Table 1–Climate Forcing Datasets; Table 2–(Bio)geochemical Modeling; Table 3–Watershed Modeling; Table 4–River Modeling; Table 5–Lake and Reservoir Modeling; Table 6–Reservoir Operations and Outflow Modeling; Table 7–Estuary Modeling; Table 8–Groundwater Modeling; Table 9–Water Reuse Modeling; and a constituents tables overview tab and the following constituents worksheets: Table 10–Water Temperature; Table 11–Salinity; Table 12–Nutrients; Table 13–Sediment; Table 14–Geologically Sourced Constituents.