The main purpose of the dam is the supply of potable water for the Brisbane, Gold Coast and Logan City regions.

From a catchment area of 1,330 square kilometres (510 sq mi) that includes much of the western slopes of the D'Aguilar National Park, the dam creates Lake Somerset at an elevation of 108 m (354 ft) above sea level, with a surface area of 4,350 hectares (10,700 acres).

[5] A small 4 megawatts (5,400 hp) hydroelectric power station is located adjacent to the dam wall.

[7] A commission of enquiry recommended Stanley Gorge as the site for a dam in 1928, but it was not until 1933 when Brisbane was in a severe drought,[4] that the Forgan Smith Labor Government adopted the reservoir's construction as a major job creation project to counter job losses caused by the Great Depression.

[7] By 1942 the dam was almost complete when workers were diverted to the war effort, with many being redeployed to construct the Cairncross Dockyard in Brisbane.

During busy periods the two camping locations can be filled to capacity with room for a maximum of 2,200 campers at Kirkleigh and 800 at Somerset Park.

[10] Lake Somerset Holiday Park's Kirkleigh campground also features cabin accommodation at the waterfront and direct access to the dam from a grassy spit.