There are 2 operational water treatment works on the Island, at Sulby and Douglas. Below is a diagram of the basic water treatment process used. If you are interested in learning more about the water treatment process you can arrange a group tour of Douglas Water Treatment Works.     

Water treatment process diagram

Opened in May 2008, Douglas Water Treatment Works provides treated water to Douglas, Onchan and the south of the Island. West Baldwin, Clypse and Kerrowdhoo Reservoirs supply raw water to the works. The water is treated and distributed via the water network to our customers. 

Douglas Water Treatment Works has replaced Glencrutchery Works which has since been demolished and the site is now owned by the Department of Education. Built in 1933, Glencrutchery was a single stage works, treating up to 18 megalitres of water daily for residents in the Douglas area.

Douglas Water Treatment Works is designed to treat up to 37 megalitres of water a day, supplying 70% of the Island's population.

Opened in October 2005, Sulby Water Treatment works provides treated water to the north of the Island. Sulby Reservoir supplies raw water to the works. The water is treated and distributed via the water network to our customers. 

Energy Recovery Project

An energy recovery system was installed at Sulby Water Treatment Works in February 2013. Raw water is piped from Sulby Reservoir to the treatment works and passes through a turbine to generate hydroelectric power. After going through the turbine the water then passes through the treatment works and onto our customers. The turbine provides up to 50% of the electricity required to run Sulby Water Treatment Works.