An Seqwater boat surveying fish life in Lake Macdonald.
An Seqwater boat surveying fish life in Lake Macdonald.

OH DAM: Threatened fish species to be rehomed

THOUSANDS of fish including the threatened Mary River Cod will be homeless when Lake Macdonald dam is emptied for repair work next year.

Details of the “grand plan” should be completed in the next two weeks, according to a spokesman from Seqwater.

We do know, however, fish will be caught, removed and rehomed from Lake Macdonald after boats specially fitted with sonar equipment count the fish.

Details of where the fish will be taken are yet to be released.

“Seqwater is developing a comprehensive recovery and relocation plan to manage fish species within Lake Macdonald and other aquatic fauna,” the spokesman said.

“This plan has been developed in consultation with key stakeholders, to manage any aquatic fauna impacted during the lowering and throughout construction.

“As part of this plan, Seqwater is currently working with contractors to identify and count fish species in the dam storage, using boats specially fitted with sonar equipment.

“Findings from these investigations will be available later in the year,” the spokesman said.

Over the past few months, Seqwater has been compiling numbers and species in the dam, which includes the threatened Mary River Cod, also an understanding of the species’ breeding cycles, to assess the best time and place to relocate them.

The huge pre-project is only one of many which will need to be undertaken in preparation for Lake Macdonald to be almost completely emptied in mid-2020.

Work will then begin for the replacement of the spillway, where the existing one has been assessed to be no longer adequate to safely contain water given new climate conditions.

If the spillway gave way under pressure, untold megalitres of water could enter Six Mile Creek, flooding land and properties along its length.

While parts of the lake will be down to a trickle of water for the duration, ironically the deepest part holding the largest amount of water is immediately in front of the spillway, so a temporary coffer dam will need to be built to hold the water back and enable the spillway to be replaced.

The $100 million project to replace the spillway will take 18 months to two years to complete.