The utility group's maintenance teams will use the pick-ups which will eventually replace South West Water's current 4x4 fleet of around 60 Land Rovers.
Damian James, transport controller at South West Water, said: 'A lot of our sites are situated on high ground and access can be difficult, especially in the winter.
'In some remote areas our vehicles spend around 90% of their working life off-road and we are confident that the L200 will cope admirably. In addition our teams are impressed with the level of cab comfort and how good they are to drive.'
South West Water plans to keep the new pick-ups for about seven years, with each new Mitsubishi coming with a 100,000-mile warranty.