The concrete dam structure is high and long. The dam wall holds back the reservoir when at full capacity. From a catchment area of that includes much of the western slopes of the D'Aguilar Range, the dam creates Lake Manchester, with a surface area of . The uncontrolled un-gated spillway has a discharge capacity of . Initially managed by the Metropolitan Water Supply and Sewerage Board, and then the Brisbane City Council, management of the dam was transferred to Seqwater in July 2008.