River Blackwater (River Loddon)

Blackwater (Loddon)
River
River Blackwater at Eversley bridge
Country	England
Counties	Hampshire, Surrey, Berkshire
Tributaries
- left	River Whitewater
Source
- location	Rowhill Nature Reserve, Aldershot, Hampshire
- elevation	135 m (443 ft)
Mouth	River Loddon
Length	27 km (17 mi)
Discharge	for Swallowfield
- average	3.07 m3/s (108 cu ft/s)
- max	42.3 m3/s (1,494 cu ft/s) (17 September 1968)
- min	0.48 m3/s (17 cu ft/s) (17 August 1953)
Discharge elsewhere (average)
- Farnborough	0.52 m3/s (18 cu ft/s)

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. It rises in Rowhill Nature Reserve, Aldershot Rowhill, an isolated remnant of the extensive heathland that once surrounded Farnborough and Aldershot. After 20 miles (32 km) 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.

The River Blackwater runs down the centre of the Blackwater Valley, which is maintained as an open space along the borders of the counties of Berkshire, Hampshire and Surrey. It runs for approximately 30 km, from the source of the River Blackwater at Rowhill Nature Reserve near Aldershot in the south, northwards to Swallowfield where the river joins the River Whitewater and then the Loddon. The Loddon eventually flows into the River Thames near Reading.

Although surrounded by urban development the Valley provides an important green corridor for local residents. As well as the Blackwater Valley Site of Special Scientific Interest (SSSI) and a small part of the Basingstoke Canal SSSI, three nature reserves within the Valley catchment and many other areas have been recognised for their ecological importance. The local planning authorities covering the Valley have designated 31 other areas as ‘Wildlife Sites’. As a result of an improvement programme, wildlife is returning, including the Otter which has been absent for over 40 years, fishing stocks are improving and the construction of the long distance riverside path has opened up much of the riverbank.