The River Plume

[GLF]

An interesting phenomenon can be observed where a stream empties into a lake. A distinct color difference between the river and lake water can commonly be observed. The area that appears to be an extension of "river-colored" water into a lake is called a “plume.†Figure 1 is a cartoon of an aerial view of a river plume. Note the distinct color difference. Although this is a cartoon representation, the color difference in actuality may be just as distinct.

You can read the whole article here.