Plunge pool height of fall, the volume of water, the resistance of the rock below the pool and other factors. The impacting and swirling water, sometimes carrying rocks within it, abrades the riverbed into a basin, which often features rough and irregular sides. Plunge pools can remain long after the waterfall has ceased flow or the stream has been diverted. Several examples of former plunge pools exist at Dry Falls in the Channeled Scablands of eastern Washington. Plunge pools are fluvial features of erosion which occur in the youthful stage of river development, characterized by steeper gradients and faster water flows. Where
Chute (racecourse) (grass) course inside of the main (dirt) track, most commonly measuring . This turf course will often be equipped with a chute of its own, extending diagonally from the stretch, to permit turf races to be run at the distance of . This diagonal chute can either consist of a more-or-less straight line, or may curve significantly, in a counterclockwise direction. In 2006 two tracks — Monmouth Park and Hollywood Park Racetrack — added a chute extending diagonally from the backstretch, to permit races at furlongs and 6 furlongs, respectively (the corresponding circumferences of these two tracks' turf courses being