River Blackwater

The River Blackwater is a tributary of the River Loddon in England and, indirectly, of the River Thames. It rises at Rowhill Nature Reserve between Aldershot in Hampshire and Farnham in Surrey and runs northwards to join the Loddon near the village of Swallowfield in Berkshire. Along part of its length, the river forms the boundary between Hampshire and Surrey, and then between Hampshire and Berkshire. Rowhill Nature Reserve is an isolated remnant of the extensive heathland that once surrounded Farnborough and Aldershot. After 20 miles the Blackwater is joined by the River Whitewater near Eversley. The river gives its name to the small town of Blackwater, Hampshire, upon the river near Camberley.

Although this article calls it the River Blackwater, Ordnance Survey maps, both ancient and modern, call it the Blackwater River. There is a small section to the west of Finchampstead which is called Long Water in both 1897 and on recent maps. The final section from the Whitewater to the Loddon is known by alternative names. The Ordnance Survey 1:50,000 map calls it the Blackwater River, the 1:25,000 map calls it the Broadwater, and the 1:2500 map calls it the Blackwater River at both ends of this section, but the Broadwater in the middle. This last option, with a small section of Broadwater in the middle where the river is somewhat wider, was also the convention in 1899.

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