Toward controlling hypoxia in Chesapeake Bay, management programs have focused for decades on reducing nitrogen, phosphorus, and suspended sediment loads from the Chesapeake Bay Watershed (CBW). In this context, the Chesapeake Bay Partnership (CBP) is currently working to improve its model-based support for the establishment of Total Maximum Daily Loads and the associated development (by others) of Watershed Implementation Plans. This project will help better quantify important nutrient and sediment trends in the major tributaries of the CBW and develop new understanding of the applicability, uncertainty, and accuracy of the WRTDS method, a state-of-the-art riverine loading estimation method developed by the USGS as an alternative to the Chesapeake Bay Model.