I believe its called a water shed but I'm not completely sure about that.
Answer
A watershed (one word) is a ridge or other dividing line between stream catchments, although the term is (confusingly) also applied to the catchment area. Another term is drainage basin.
the area from which water drains into a river is called the river's catchment. A river's watershed is the connecting ridges surrounding the watershed, and separating it from adjacent ones.
The land beside a river is called a riverbank. It is the area along the edge of the river where the water meets the land.
When sediment collects in an area, it is called sedimentation. This process occurs when particles settle out of a fluid and accumulate on a surface, forming layers of sediment over time.
Watershed- the area of land where all of the water drains into a common water body, such as a river, lake, or ocean.
Watersheds are sometimes referred to as drainage basins or catchment areas. These terms describe the land area that collects and funnels water into a river, lake, or ocean.
The land area where a river collects water is known as its watershed or drainage basin. This is the area of land where all the water that falls within its boundaries flows into a specific river or stream.
A drainage basin/ watershed.
the area from which water drains into a river is called the river's catchment. A river's watershed is the connecting ridges surrounding the watershed, and separating it from adjacent ones.
water shed
It is called a delta.
Deltas.
The land beside a river is called a riverbank. It is the area along the edge of the river where the water meets the land.
The area of land drained by a river is called a "catchment area". It is so-called because is the the area that catches the precipitation (rainfall).Another term is "river basin", but this is less specific.(The geographical term, "catchment area", is often used to describe the area served by, say, a school or hospital).
Horseisle Answer: Estuary
When sediment collects in an area, it is called sedimentation. This process occurs when particles settle out of a fluid and accumulate on a surface, forming layers of sediment over time.
the river runs into the ocean.... its called brackish water
Watershed- the area of land where all of the water drains into a common water body, such as a river, lake, or ocean.