River Allen, Dorset

River Allen
The river close to Furzehill
Country	England
County	Dorset
Tributaries
- right	Crichel Stream
Source
- location	Monkton Up Wimborne, Dorset
- coordinates	50°55′15.1″N 1°58′52.6″W / 50.920861°N 1.981278°W / 50.920861; -1.981278
Mouth
- location	Wimborne Minster, Dorset
- coordinates	50°47′33.4″N 1°58′43.3″W / 50.792611°N 1.978694°W / 50.792611; -1.978694Coordinates: 50°47′33.4″N 1°58′43.3″W / 50.792611°N 1.978694°W / 50.792611; -1.978694
Length	14 mi (23 km)
Basin	40 sq mi (104 km2)
Location within Dorset

River Allen is a river in the county of Dorset in South West England. It flows for 14 miles (23 km) and has its confluence with the River Stour in Wimborne Minster.

River Allen starts at Wyke Farm as a winterbourne and flows down to Monkton Up Wimborne and then tracks its way to the Watercress farm, follows down to Honeybrook Farm, to a mill and then to Canford Bridge in Wimborne Minster that is the mouth of the river. The river is known as a classic chalkstream which supports a good fishery for trout and used to support a good salmonid population.

Since 1946, the water from the Allen has been abstracted for domestic and industrial use. The amount of water taken was having a detrimental effect on the river flow whilst at the same time the salmonid population dropped significantly. Studies have been undertaken as a correlation between the two events and have resulted in the abstraction rate being reduced by 50%.

The Allen had the strongest population of white clawed crayfish in Dorset and measures such as tree planting and slowing the flow of the river down were implemented to help the species. However, an outbreak of Crayfish Plague was discovered on the river in 2014 with at least 100 of the native species found dead in the river.