Posted on November 16, 2022
As dredging works at Port MacDonnell harbour wind down, concerns remain for the long-term health of the artificial breakwater.
Local fisher of 20 years Nick Richards said dredging by the Department of Infrastructure and Transport (DIT) had not achieved the desired outcome of clearing silt and weed from the bay.
“When we’re talking about the weed and the sand, all they’ve done is just shift the problem from one spot to another,” Mr Richards said.
“We’re starting our boats and they’re full of weeds because of the amount of weeds that are actually floating in the harbour.
“It’s going to be condemned in two years’ time because it’s going to be that full of weed.”
Mr Richards says removing sand from the ramp to the jetty would draw in weed and silt.
Mr Richards was one of the fishers consulted on how best to tackle the ongoing issue of weed and silt behind the breakwater, where as many as 60 fishing boats have operated under licenses paid to the state government.
He said dredging a channel along the breakwater was only a stop-gap measure and engineers had to work with the artificial structure.
“There is an easier way to clean it because gravity always wins,” Mr Richards said.
“The ocean floor next to the boat ramp is the deepest part of the harbour.
“You have to dig a big trench next to that so that the weed collects in the hole, then you have a point where an excavator can dig it and remove it to landfill.”
Mr Richards says coastal build-up by the harbour is an ongoing issue.
Stagnant bay
Roger Cutting has been fishing at Port MacDonnell for 50 years and says the bay will not stop silting up.
“You can see it where we put the culverts through the breakwater years ago to try to increase the natural flow,” he said.
“The sand comes in, swirls around and stays there.”
A channel from the boat ramp (left) has been dredged behind the breakwater.
Mr Cutting said opening up the breakwater wider could exacerbate the problem.
“It’s just like when you dig a trench at home; it rains and dirt sinks in and it eventually builds up,” he said.
Regular maintenance needed
Both Mr Richards and Mr Cutting agreed that ongoing maintenance of the harbour was crucial to keep it viable for commercial fishers.
“Over at Beachport, they come down and pump it out at least once a year,” Mr Cutting said
“That’s what we need here to deal with all the stagnant sediment, seaweed and muck or it’s just going to keep filling up.
“They need to be cleaning it out no less than every two years.
“The last big cleanout was in 2006 and it took all this time to get them back. That’s over a decade of build-up.”
DIT has committed to maintaining safe operating conditions within the harbour.
Mr Richards said the time and expense of the recent dredge was a missed opportunity to plan for a long-term solution.
“We’ve already changed nature down here and now we have to keep working on it,” he said.
“Without a natural point of collection, they’re going to have to dredge again and again and again because the problem is not getting fixed.”
A spokesperson for DIT said while extensive consultation was undertaken for the dredging plan, digging a hole by the jetty was not considered a “practical long-term solution”.
“[DIT] will continue to monitor the seagrass wrack that may accumulate in the channel and along the beach,” they said.
“Should a build-up occur, we will work with the District Council of Grant, the Environment Protection Authority (EPA) and any other relevant authorities to determine the most appropriate intervention.
“The department, along with council and the EPA remains committed to providing continued safe, navigable access to the harbour.”
