Photographing water in the form of a river, stream, or waterfall within a landscape image has a number of challenges. Probably the biggest obstacle is achieving the right exposure since the white bubbling water can fool a meter into under exposing the image. Fortunately, the digital cameras of today give the photographer tools to get great water exposures.

Photographing Water in Landscapes by Tibor Vari as published in the July 2008, PSA Journal.
Falling Water Photography