Blackwater River (River Axe)

Blackwater River
Course and catchment of the Blackwater River
Location
CountryEngland
CountiesDevon, Dorset
Physical characteristics
Source 
  locationMarshwood, Dorset
  coordinates50°47′58″N 2°52′30″W / 50.799500°N 2.874986°W / 50.799500; -2.874986
MouthRiver Axe
  coordinates
50°48′59″N 2°57′36″W / 50.816404°N 2.959915°W / 50.816404; -2.959915
Length10 km (6.2 mi)

The Blackwater River is a 10-kilometre (6.2 mi) long river in the counties of Dorset and Devon, in the south-west of England. It rises to the north of Marshwood in Dorset, flowing north and west to join the River Axe at a point north of Axminster in Devon. For most of its length it forms the county boundary between Dorset and Devon.