HEC-SSP Tutorials and Guides Current: Combining Precipitation-Frequency and Flow-Frequency Results PDF Download PDF Download page Combining Precipitation-Frequency and Flow-Frequency Results. Current page Include child pages All pages Combining Precipitation-Frequency and Flow-Frequency Results Bulletin 17C Flow-Frequency augmented by Precipitation-Frequency with HEC-HMSModeling Flow-Frequency Relationships using HEC-HMSCombining Flow Frequency Curves Determined by Independent Estimates ×