part of stream water body hydroform stream pool 2023-08-25T17:42:00.901Z A water body which is created in a stream by local scour or impoundment and has some structural control. Pool water depth is above average for the stream. If if all the running water in the stream was shut off, areas in the stream that still hold water are pools. Pool water velocity is below average for the reach, causing fine sediments to deposit in pools. Pools are generally longer than they are wide (unless they are plunge pools), and are 1.5 x deeper at their maximum depth than they are at their crest pool