WordNet (r) 3.0 (2006):

outflowing
    adj 1: that is flowing outward [syn: effluent, outflowing]

Moby Thesaurus II by Grady Ward, 1.0:

24 Moby Thesaurus words for "outflowing":
   defluxion, discharge, drain, drainage, effluence, effluent, efflux,
   effluxion, effused, effusion, effusive, exhalation, exhaust,
   extravasated, flowoff, gush, outbound, outfall, outflow, outgoing,
   outpour, outpouring, outward-bound, runoff