HEC-HMS Tutorials and Guides Modeling Reservoirs in HEC-HMS Current: Applying Reservoir Volume Reduction Methods in HEC-HMS PDF Download PDF Download page Applying Reservoir Volume Reduction Methods in HEC-HMS. Current page Include child pages All pages Applying Reservoir Volume Reduction Methods in HEC-HMS Introduction to the Reservoir Volume Reduction Methods Task 1: Reservoir Volume Reduction Modeling with Outflow Structure Routing Method (Elevation-Area) Task 2: Reservoir Volume Reduction Modeling with Outflow Curve Routing Method (Elevation-Storage-Area-Discharge) Task 3: Reservoir Volume Reduction Modeling with Rule-Based Operation Method (Elevation-Storage-Area) ×