Paul Weston

October 31, 2009

THE threat of a stormy and wet summer has pushed the $395 million project to double the capacity of the Hinze Dam on the Gold Coast to crisis point.

Project managers must decide whether to gamble on proceeding with critical work building the exposed clay core of the dam wall, or wait until the wet season finishes next year.

Before workers can start raising the dam wall by 15m, they have to strip away rocks to expose the clay core base.

Clay supplies are then brought in to add to the core before more rocks can be replaced as a barrier on the outside.

But the delicate work can only proceed in fine weather.

SEQ Water has confirmed work cannot proceed if the dam reaches full capacity and it said steps were being taken to reduce the current catchment level by pumping more water into the South East Queensland Water Grid.

Other emergency measures include having the desalination plant at Tugun working at only one-third of its capacity and Hinze, which usually pumps out about 120 megalitres a day, providing almost double that amount to residents on the grid north of the Coast.

Hinze Dam is currently at 89.6 per cent capacity, with water restrictions on the Gold Coast suspended until December 1.

The dam upgrade will almost double its storage capacity from 169,000 megalitres a year to 309,700, adding 6000 megalitres of drinking water a year to the SEQ Water Grid.

Hinterland-based Gold Coast city councillor Ted Shepherd, who receives regular briefings on the upgrading of the dam wall, told The Sunday Mail that project managers must make a decision within the next fortnight.

“Either they make the decision now to strip off the top coat (of rocks) and hope they have normal sunny weather to get everything in place or they wait until after the storm season,” Cr Shepherd said.

“If they wait until next year – until March or April – it will put them behind schedule.

“The problem is they can’t expose that centre core of the dam for too long. They can’t work in wet weather.”

About 280 workers are employed in the project, which requires the transfer of 430,000 tonnes of clay and 5 million tonnes of rock.

“They’re at a crucial time,” Cr Shepherd said.

A SEQ Water spokesman said the State Government and SEQ Water had taken measures to ensure water was not being wasted while keeping the project on track.

“The project is at a critical stage where we are starting the process of raising the dam wall. This work would not be able to proceed if the dam was at full capacity,” the spokesman said.

Workers cannot work in the rain and if heavy rain filled the dam there would be a Workplace Health and Safety issue with “water lapping around their working area”, he said.

The Tugun Desalination plant has also reduced its production but “no increase in consumption was required or expected” from Gold Coast residents, the spokesman said.

The project currently remains on track for completion in December 2010.