Is there a size limitation on the watershed being modeled? I’m being asked to run a model on a 100-200 acre drainage and I was checking to see if results would be skewed due to smaller watershed size.
HEC-RAS does not perform hydrology calculations; it will simply perform hydraulic calculations based on the flows you input. However, to answer your question the size limitation is based on your methodology of calculating run-off i.e. rational, SCS, Regression, ect. Each method does have a minimum applicable drainage are size.