Fishway complete

Work to create a fishway at Horseshoe Bend has been completed.

The fishway is designed to restore water flows around Horseshoe Bend and reconnect the Thomson River.

Chief Executive Officer of the West Gippsland Catchment Management Authority, Martin Fuller, said that after so many years of preparation it was exciting to see the flows restored.

“Over the past few weeks, we tested the performance of the fishway to make sure it was operating as intended. It performed very well and has now been fully commissioned.”

“The fishway also met all the compliance requirements and specifications of the plan, which is extremely satisfying,” said Mr Fuller.

“In addition, once work began on site, the contractors realised the existing stream profile matched the fishway design in several places, which meant we did not need to excavate as much as originally thought.”

Mr Fuller said that more than 60 per cent of the water flow was being retained to the Horseshoe Bend Tunnel.

“The split of water was intended to be 60 per cent to the tunnel and 40 per cent to the fishway. After on-site testing slightly less than 40 per cent is being directed to the fishway. However, this hasn’t been an issue as the fishway hydraulics are performing well.”

Restoring the flow around Horseshoe Bend will reconnect the upper reaches of the Thomson River.

“This is vital for improving the health of the river and will open up more than 85kms of new habitat for migratory fish species,” said Mr Fuller.

Rehabilitating the area
Now that the fishway has been completed, work will begin on the rehabilitation of the site.

“Obviously, the site and access tracks have been disturbed during the creation of the fishway and the fires at the start of the year also damaged the area,” explained Mr Fuller.

“The access track was temporarily widened and will now be narrowed back to its original size. The project has an Environmental Management Plan and the area will be rehabilitated in accordance with that.

“We expect the area will regenerate over the next three to five years, but initially, visitors to the area will notice the difference.”

Mr Fuller said full rehabilitation of the site was a key priority for the CMA and it would be closely monitored.

“We will also work closely with the Department of Environment Land Water and Planning  (DELWP) to control weeds in the area, both to protect the site and ensure the fishway continues to function as required.”

As well as plant regeneration around the site and access tracks, other changes include the installation of stepping-stones as part of the walking track, and submerged rocks near the tunnel exit.

“To provide an area of less turbulent water near the tunnel exit and allow fish to effectively navigate upstream, large submerged rocks were installed as part of the design,” explained Mr Fuller.

“The rocks, which are placed near the middle of the river, break up the water flow and prevent fish from being swept up in the turbulent flow out of the tunnel. The stepping-stones have been installed to provide river crossing points for bushwalkers.”

It is expected that with good weather, the site will be reopened to the public by the end of August.

Published Wednesday June 26th 2019

Fishway at Horseshoe Bend
Rehabilitation and revegetation works have commenced around the newly commissioned fishway which has been designed to be a visual low-impact waterway.
Rocks at outlet Horseshoe Bend Tunnel
Submerged rocks at the tunnel exit are designed to break up the water flow and help prevent fish being swept up in the turbulent flow out of the tunnel.