The estuary

Close to the sea, the river flows very slowly, and it begins to deposit most of its load. The load that the river carries near the sea is made of very small particles of mud and silt. As the river flows towards the sea, these particles are left by the side of the river as mud flats.

Close to the sea the mudflats will be covered by sea water each time the tide comes in, but inland the mudflats may stay above the sea water and plants will begin to grow on them.

Estuaries are good places for sailing boats, and you will often see boats lying on the mudflats when the tide has gone out.