Backwater

Back·wa·ter

Backwater

n.
  1. Water turned back in its course by an obstruction, an opposing current, or the flow of the tide, as in a sewer or river channel, or across a river bar.
  2. An accumulation of water overflowing the low lands, caused by an obstruction.
  3. Water thrown back by the turning of a waterwheel, or by the paddle wheels of a steamer.