1) Tidal standstill
Found on
https://www.crosswordclues.com/clue/deadwater
[topography] A deadwater is that part of an estuary through which there is little to no water flow. In situations where a river flow is weaker than the marine processes that build sand dunes, the river may be obstructed from flowing into the sea by the formation of a sand dune; that is, a sandbar. In such cases the river will often form an ...
Found on
http://en.wikipedia.org/wiki/Deadwater_(topography)
No exact match found.
