As part of Seqwater’s Dam Improvement Program, Hall was engaged to undertake a safety upgrade to Ewen Maddock Dam – a 370-hectare dam that supplies drinking water to South-East Queensland.

The project involved:

• Installation and management of one of the largest temporary siphon systems in Australia (capable of lowering dam levels at a minimum of 10,000 L/s) to manage the safe release of water over the spillway. Lowering the dam levels to approximately 60 per cent capacity enabled the crew to safely carry out earthworks along the dam wall.
• Installation of an internal chimney filter to existing dam crest level and reinstatement of the outer earth fill zone to buttress the new filter.
• Construction of a reinforced concrete wall along the crest of the dam to increase flood capacity.

Careful consideration was also given to managing seepage within the existing embankment, and the project was successfully completed months ahead of schedule.