Arc Hydro is a set of data models and tools that operates within ArcGIS to support geospatial and temporal data analyses for water management.
With Arc Hydro you can delineate and characterize watersheds in raster and vector formats, define and analyze hydro geometric networks, manage time series data, and export data to numerical models.
Setup files are available for free download: ArcGIS 9, ArcGIS 10, ArcGIS 10.1, ArcGIS 10.2, ArcGIS 10.3, ArcGIS 10.4 and ArcGIS Pro.
http://downloads.esri.com/archydro/archydro/Setup/
Tutorial data in PDF (and data for tutorial)
http://downloads.esri.com/archydro/archydro/Tutorial/