Work progressing well on canal clean-up
Friday 8 October 2004
Work progressing well on canal clean-up after floods
Flood-silted drains and canals in the Eastern Bay of Plenty are being cleaned up “at full speed” by Environment Bay of Plenty.
Works engineer Roger Waugh says staff and contactors began the work immediately after July’s storm event. However, the sheer scale of the task means they won’t be finished until early next year.
The regional council manages about 350km of drains and canals on the Rangitaiki Plains on behalf of the ratepayers of the 34 communal pump schemes, the Rangitaiki Drainage Scheme, and the two major river schemes, the Rangitaiki-Tarawera Rivers Scheme and the Whakatane-Waimana Rivers Scheme.
It estimates 80km of waterway needed de-silting as a result of the storm. In some cases, that can involve digging out a metre thickness of sediment – possibly from a canal eight metres wide.
Mr Waugh says the drains and canals have to be brought up to standard “so they can do their job properly”. “If they are silted up, it reduces their capacity to drain water. So when it rains heavily, as it did last night, you’ll find surface water in places where it would normally be fairly dry.”
Mr Waugh says up to a quarter of the waterways are now cleared, including many of the worst affected ones. “Some drains had no drainage capacity left in them, especially those in the low areas of farmland below where stopbanks breached.” The floodwaters near the breaches carried huge loads of silt during the event, he explains.
Many Rangitaiki Plains landowners worst hit by the flood have already cleared out their own drains, sometimes with financial support from the Government’s relief package for farmers. Environment Bay of Plenty has applied to the Government’s Disaster Relief Fund for reimbursement of costs associated with the de-silting of drains and canals.
CAPTION: A six kilometre length of Reids Central Canal, near Edgecumbe, needs to be de-silted after the flood. It will take a digger about six weeks to do the job. The dredged up material must also be removed from inside the floodway – a major task in itself.