Dam water reduced for probe

SEQWATER is lowering the water level of Lake Macdonald at Noosa ahead of investigative works as part of the bulk water authority’s Dam Improvement Program.
The lake water level will be lowered to about half a metre below the current full supply level to enable the works to be completed.
Seqwater chief executive officer Peter Dennis said the temporary lowering of the dam would not affect water security.
“The controlled releases of water required to achieve the lowering are not expected to have any environmental impacts. We have increased monitoring of the dam environment during the process and we encourage our dam neighbours to get in touch if they become aware of any potential problems,” Mr Dennis said.
“We are lowering the water level by releasing water through the outlet valve as well as a number of temporary siphons installed on the spillway crest. We expect the water level will be lowered by mid-September, so investigations can begin.”
Mr Dennis said the investigation work on the spillway at Lake Macdonald was expected to take about four weeks, subject to weather delays.
“Work on the spillway slabs will be conducted between 7am and 5pm, Monday to Friday, with the assistance of a mobile crane,” he said.
“We will be using cutting tools and some machinery, so intermittent construction noise can be expected.
“We appreciate the patience of the local community as we undertake this essential work.”
Mr Dennis said the investigations would help inform the timing and scope of the planned Lake Macdonald dam upgrade.