An estuary is where the salt & fresh types of this are mixed
This type forms where a large river inputs lots of fresh water in an area 
where... [DOC] [TLE] Types of Estuaries | Oceanscape Network [PAR] The mix of salt and fresh water in an estuary can depend on the flow of the river, 
the ... Salt Wedge Estuary: This type of estuary occurs when a very large and... [DOC] [TLE] NOAA's National Ocean Service Education: Estuaries [PAR] Salt-wedge estuaries are the most stratified, or least mixed, of all estuaries.