[1] The dam was constructed in 1933 and enlarged in 1956,[2] and the power station was built from 1954 to 1956 and commissioned on 3 July 1956.

In December 2009 the Water Corporation started a $41 million project to strengthen the dam wall.

[5][6] Wellington Dam was built in the early 1900s to supply water to the Great Southern Towns Water Supply system – the pipeline system that supplies water to the Wheatbelt towns in southern WA, as far north as Northam, east to Lake Grace, south to Katanning.

[citation needed] Wellington Dam was originally built in 1935 with a storage capacity of 35 gigalitres (1.2 billion cubic feet) as a source of irrigation on the coastal plains.

The dam was raised over the years and reached its current capacity is 185 gigalitres (6.5 billion cubic feet) in 1960.