Top End water supply solution wins $6m final design contract

The next step has been taken towards solving the Top End’s freshwater supply challenges. Read what was done.

Darwin-based national water infrastructure specialists SMEC Australia has won the contract to deliver final concept designs for the AROWS water storage project.

The 12-month, $6m contract will deliver the final concept drawings for the showpiece project that’s intended to secure Top End water supplies for the next 50 years.

The Adelaide River Off-Stream Water Storage project is the Territory government’s long-term solution to replace Darwin River Dam as the Top End’s main water supply.

Located just north of Lake Bennett, the project will take advantage of a naturally occurring basin made up of a ridge formation next to Adelaide River.

Two concrete containment barriers will be constructed at low points for the water to be stored.

SMEC area manager Jocelyn Ellero.

The federal government has kicked in $300m to implement the Darwin Region Water Supply Program including redeveloping parts of Manton Dam for public water supply.

SMEC Australia area manager Jocelyn Ellero said the company had a 40-plus year involvement delivering water supply solutions to Darwin and the Top End.

“The AROWS project is part of SMEC’s DNA,” Ms Ellero said. “Forty-four years ago SMEC was part of the Darwin regional water supply study and that was our entry into the Northern Territory.

“Twelve years ago we set up an office here and since then we’ve been heavily involved in all the previous investigations for the AROWS project including the pre-feasibility work to understand if it was actually possible to have a dam there.”

Over the next few weeks members of her dozen-strong team will work to further understand key infrastructure requirements and identifying missing geological gaps.

“We need to further progress the geological understanding, so over the next few weeks of the wet season we’ll be better understanding the dam infrastructure and other key infrastructure sites and identifying what are the missing geological gaps,” she said.

SMEC area manager Jocelyn Ellero, Territory Development Minister Eva Lawler and DIPL's Evan Tyrrell.

SMEC will also complete the concept design and provide a project cost estimate.

Current modelling showed AROWS will hold about 250GL when full and supply 60GL to the Darwin region.

Territory Development Minister Eva Lawler said AROWS made use of the region’s natural catchments.

She said AROWS would provide drinking water for the Top End, Middle Arm manufacturing and Lambells Lagoon agricultural precinct.

“Instead of damming the Adelaide River you have a natural catchment area so at peak times when a lot of water flows, we’ll be taking that water from the off-flow at Adelaide River and storing it in that catchment area,” she said.

“What we’re doing is allowing the Adelaide River to flow throughout the year, but what you’re doing is taking water off there and putting it into this natural storage area.”