TVA's Weekly Scheduling Model (WSM) is a home-grown Fortran model of the 42 reservoirs in the TVA system that solves at a weekly timestep. TVA has long used the WSM for long-term resource planning studies and to provide data on hydropower capabilities to TVA's power supply models. As part of the River Models Optimization (RMO) project, TVA collaborated with CADSWES to develop a new Long-term Model using RiverWare Rulebased Simulation and Distributed Multiple Run Management to replace the WSM. The new LT Model solves at a 6-hour timestep, which combined with the RiverWare rule logic provides a more refined representation of the TVA hydropower system. This presentation will provide an overview of the model, including the background and motivation for the new model, the use of RiverWare scripts to facilitate running the model for seven distinct use cases, each with its own use of MRM and unique set of post-processed outputs, integration with TVA's FEWS system, and benefits of the updated modeling approach. The presentation will also describe how a number of RiverWare enhancements to MRM, scripting, and ensemble data analysis were implemented to support the LT Model use cases.