The River Whitewater flows through Hampshire and is a tributary of the River Blackwater near Swallowfield. Its headwaters flow over chalk and there is little pollution making the river Whitewater rich in wildlife.

The river contains a variety of species of fish including brown trout, dace, barbel, perch, pike and chub.

Like many rivers in the south of England, non-indigenous mink and signal crayfish are present.