The Collaborative International Dictionary of English v.0.48:

Sluice \Sluice\, v. t. [imp. & p. p. Sluiced; p. pr. & vb. n.
   Sluicing.]
   1. To emit by, or as by, flood gates. [R.] --Milton.
      [1913 Webster]

   2. To wet copiously, as by opening a sluice; as, to sluice
      meadows. --Howitt.
      [1913 Webster]

            He dried his neck and face, which he had been
            sluicing with cold water.             --De Quincey.
      [1913 Webster]

   3. To wash with, or in, a stream of water running through a
      sluice; as, to sluice eart or gold dust in mining.
      [1913 Webster]

WordNet (r) 3.0 (2006):

sluicing
    adj 1: pouring from or as if from a sluice; "the sluicing rain"