Cooperative operation of a parallel, two-reservoir system may produce more benefits than independent operation. Storage reallocation and re-operation project alternatives are evaluated for New Bullard’s Bar and Oroville Reservoirs in the Feather- Yuba River basin of California. Ideas for re-operation project alternatives were generated using participatory input from ?????. Reallocation and re-operation project alternatives were simulated on a monthly computation interval over the historical period of record using HEC-5 and on an hourly timestep over 34-day probabilistic-based synthetic flood events in HEC-ResSim. Simulation results were evaluated using indicators for water supply reliability, resiliency, and vulnerability, expected annual flood damage, and ability to meet flow objectives at 6 Feather-Yuba basin locations. Results show tradeoffs between EAD and water supply reliability in the Feather and Yuba River basins for each project alternative. The study complements ongoing flood protection improvement investigations within the basins and demonstrates a further use of HEC-ResSim and HEC-FIA software for reservoir system simulation, flood impact analysis, and planning studies within the Corps Water Management System (CWMS) software suite. Recommendations highlight both (i) topics requiring further study for flood protection improvements in the Feather and Yuba basins and (ii) capabilities that should be added to HEC-ResSim, HEC-FIA, and CWMS to make the programs better suited for planning analysis.