The River Whitewater rises at springs near Bidden Grange Farm between Upton Grey and Greywell. It flows northeast through Hampshire

Hampshire

Hampshire is a county on the southern coast of England in the United Kingdom. The county town of Hampshire is Winchester, a historic cathedral city that was once the capital of England. Hampshire is notable for housing the original birthplaces of the Royal Navy, British Army, and Royal Air Force...

 and is a tributary of the River Blackwater

River Blackwater (River Loddon)

The River Blackwater is a tributary of the River Loddon in England and, indirectly, of the River Thames. It rises at Rowhill on the outskirts of Aldershot between Aldershot in Hampshire and Farnham in Surrey and runs northwards to join the Loddon near the village of Swallowfield in Berkshire...

 near Swallowfield

Swallowfield

Swallowfield is a village and civil parish in the English county of Berkshire. It is situated south of the town of Reading, and north of the county boundary with Hampshire....

. Its headwaters flow over chalk

Chalk

Chalk is a soft, white, porous sedimentary rock, a form of limestone composed of the mineral calcite. Calcite is calcium carbonate or CaCO3. It forms under reasonably deep marine conditions from the gradual accumulation of minute calcite plates shed from micro-organisms called coccolithophores....

 and there is little pollution making the River Whitewater rich in wildlife. It was noted on Janssen's map of Hampshire

Hampshire

Hampshire is a county on the southern coast of England in the United Kingdom. The county town of Hampshire is Winchester, a historic cathedral city that was once the capital of England. Hampshire is notable for housing the original birthplaces of the Royal Navy, British Army, and Royal Air Force...

 of 1646.

The settlements of Greywell

Greywell

Greywell is a small village and civil parish in Hampshire, England.Greywell village is a past winner of the Best Kept Village in Hampshire competition and a recent winner of Best Small Village in Hampshire. The Basingstoke Canal runs underneath part of the village through the 1.1 km long...

, North Warnborough

North Warnborough

North Warnborough is a small village situated in North East Hampshire. Its neighbouring villages are Odiham, Hook and Winchfield and the current representative of Parliament is the Rt. Hon. James Arbuthnot...

 and Hartley Wintney

Hartley Wintney

Hartley Wintney is a large village and civil parish in the English county of Hampshire.-Location and character:Hartley Wintney is in the Hart district of North-East Hampshire...

lie on the river Whitewater.

The river contains a variety of species of fish including brown trout, dace, barbel, perch, pike, roach and chub. Fishing on part of the river is controlled by Farnborough and District Angling Society which has separate coarse and fly fishing sections.. Like many rivers in the south of England, non-indigenous mink and signal crayfish are present.