Heavy rainfall from three years of La Nina has led to erosion of stream banks across the ACT region, with Canberra's urban catchments among those worst affected.
Saturated catchments and more frequent high flows has left urban and rural waterways vulnerable to erosion and work is now required to improve structural integrity of banks.
Planting of trees and native plants is already underway with the aim of capturing nutrients and slowing down water flowing into catchments.
Conversely, above-average rainfall has contributed to water quality improving across the ACT, the annual Waterwatch health report revealing 2022 was the best in the report's history.
The report is based on the results of almost 2000 surveys conducted by volunteers at 237 sites across the ACT region.
Eight of the 87 reaches surveyed were scored as in excellent condition, one more than in 2021 and the highest number in the nine years the report has been produced. None of the reaches received a degraded score and Tuggeranong Creek's Isabella Pond was the only reach to rank poorly.
The Y-shaped network of two concrete stormwater channels run from Leinhop Street in Theodore to join another channel flowing south west from Fadden near Isabella Drive where the channel then flows into Isabella Pond.
Water Minister Shane Rattenbury said the concrete drain would soon be ripped up and naturalised. It's one of several naturalisation projects proposed for Tuggeranong designed to restore the health of its waterways.
Mr Rattenbury said the erosion of stream bank was especially the case in urban and rural areas with low numbers or diversity of native vegetation, both in-stream and along the riverbanks.
"This highlights the importance of restoring our urban and rural waterways to protect waterway health, restore biodiversity and make waterways more resilient to extreme weather conditions," he said.
Platypus survey results have also been released, with 21 individual platypus sighted during the data collection month.
The sighting was 10 less than during the same period in 2020.
Mr Rattenbury said it was likely a consequence of high flows disrupting platypus feeding behaviour.
Woo O'Reilly, Upper Murrumbidgee Waterwatch Facilitator, said eroded soil entering the waterways smothered the substrate, including the rocky bottoms where water bugs live.
"When you smother that landscape, you eliminating a prime water bug habitat," she said.
"That's food for platypus and for Murray cod."
Federal funding has been secured to undertake restoration projects post flood and erosion events, including along creek lines in the Gudgenby Valley.
The improvements are expected to lessen the impact of future droughts by encouraging the retention of water.
Ms O'Reilly said the ACT's waterway system was much more than just drains or an avenue for sending water somewhere else.
"It's an ecosystem that is filtering water, that's providing habitat for bugs that are food for fish, that are food for birds," she said.
"Ultimately when you have a healthy waterway you have a healthy community because we all benefit from the complexity that comes with a healthy stream."
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