A useful site describing the connection between groundwater and surface water curated by the
Australian Bureau of Rural Sciences.
It finally occurred to me to google for
hydrology wiki. This turned up the FloodRiskNet catalogue of methods, which deals with methods for uncertainty analysis in flooding risk estimation, the Experimental Hydrology wiki, and the Distributed Hydrological Modelling wiki by Ricardo Rigon and his crew at the University of Trento.
And they even appear to be live.