The Collaborative International Dictionary of English v.0.48:

Inflow \In*flow"\, v. i.
   To flow in. --Wiseman.
   [1913 Webster]

WordNet (r) 3.0 (2006):

inflow
    n 1: the process of flowing in [syn: inflow, influx] [ant:
         effluence, efflux, outflow]