
Peter Thompson has over three million dollars worth of equipment to complete the dredging project.
By George Driver
A proposal to dredge a navigable channel in the Mahurangi River is edging forward and a resource consent is expected to lodged later this year.
The Mahurangi River Restoration Trust made a presentation to the Rodney Local Board’s business meeting on April 12 to update the Board on the project.
The Board has given a $20,000 grant to the trust to investigate the dredging.
Trustee Peter Thompson says he hopes the consent will be granted early next year, but starting the dredging will depend on funding. The project is expected to cost between $2.5 to $3.5 million and a significant fundraising campaign is planned and ongoing Council funding would also be required.
Mr Thompson told the Local Board it would just take two significant floods to make the river unnavigable and about 100,000 tonne of sediment came down the Mahurangi River every year.
“The depth at the moment is really concerning,” Mr Thompson said. “Year by year it’s less and less.”
The Jane Gifford was sitting high and dry on mud for two hours at every low tide due to sediment build-up, he said.
The level of sediment at the Warkworth wharf was also causing the pontoons to chafe against the wharf and they might need to be replaced if the friction continued.
The goal of the project was to dredge a 15-metre wide channel which would be 1.5 metres deep at low tide and allow boats all-tide access.
If the Warkworth basin was dredged to a significant depth it could also act as a sediment trap, preventing silt from building up down stream and creating a relatively contained area to maintain.
Finding a site to dispose the dredgings was ongoing, but Mr Thompson said a number of options were being explored on farmland along the river and at Mahurangi East. The dredgings would be buried on land. Topsoil from the site would be removed and a layer of clay put down, before dredge spoil was spread over the site. The site could be restored later by putting a clay cap over the dumpsite and returning the topsoil.
Over $100,000 of work towards the consent had been done pro-bono by a number of local businesses, including O’Connor Planning Consultants, Buckton Consulting Surveyors and Hutchinson Consulting Engineers.
Trustee Hugh Gladwell said the dredging could transform the town and be a boon for tourism.
“The benefits are huge,” Mr Gladwell. “The river is Warkworth’s greatest asset, both for tourists and locals.”
He said once the river was dredged, ferries could start running from Warkworth to Auckland and it could be a significant boost to the local economy as more boats visited the town.