Alan Birchmore AO was LFA chairman from 2012 to 2018. Raking the estuary started in 2013. Mr Birchmore was recognised as an Officer of the Order of Australia in 2016 for his contribution to the community in flood mitigation.

"It is four years since any sediment was actively removed from the yacht basin, Home Reach and the Seaport," he said.

Mr Birchmore estimated in that time that build-up would be around 400,000 cubic metres that have been left to accumulate.

However, the jury is still out on whether dredging the Tamar is the best option, with the delayed release of a scientifically based report compiled by the Tamar Estuary Management Taskforce.

RELATED STORY: Liberals choose dredging regardless of scientific report

TEMT was expected to release the sediment management report by March but has been delayed until "the first quarter of 2021".

TEMT advised the report would not be released before the election due to the government's caretaker conventions.

Mr Birchmore said dredging was expensive and limiting, but doing nothing was no longer an option.

"No doubt the government intends to target the main areas of difficulty, the yacht basin, where the Tamar Rowing, Tamar Yacht Clubs and Tamar Cruises are having difficulty accessing their facilities," Mr Birchmore said.

"Also the Seaport the major attraction for locals and visitors alike and which is an area of considerable siltation."

Dredging programs in the Tamar have not been in operation, except for a Southern Marine Shiplift program. It's understood dredging stopped to wait for the outcome of the TEMT report.

While some have criticised the government for taking action before releasing the report, Mr Birchmore disagreed.

"In terms of the TEMT report, there is a reason that there has been no response -there is no silver bullet. But somehow sediment must be removed, the options are few and don't need four years to understand," he said.

"Therefore it would be unreasonable for the government to wait for yet another report before taking positive action."

Premier Peter Gutwein announced the dredging program promise would make use of existing sediment siltation ponds in Launceston. City of Launceston general manager Michael Stretton said the silt ponds were in use as far back as the 1950s but had not been used in the past 30 years. The ponds are located at Ti Tree Bend and the West Tamar Walking Trail, and at each location, there are three interconnected ponds.

READ MORE: Our history | Dredging up the history of Tamar's ill-fated Ponrabbel

"The time it takes to treat dredged material differs depending on various factors. The aim is to make the material benign prior to its disposal."

Labor has not released a policy regarding the Tamar Estuary. However, the Greens has proposed a kanamaluka/River Tamar Management Authority with a scientific advisory panel.