The unusually dry winter has forced Whakatāne District Council to undertake dredging operations at the Whakatāne River bar, starting this week.
Dredging will happen on the outgoing tide and aims to loosen the compacted sand between the ‘narrows’ at the river entrance and the river bar, about 50 metres offshore. The loose sand will be taken out to sea in the tidal current, to a point where a proportion of it will carried away by the west-east current along the coast.
“Whakatāne Coastguard and a number of commercial and recreational users have indicated that the water depth between the narrows and the bar has reduced to a point where safety is being compromised,” says Harbour Superintendent Isaac Tait. “At low tide, with the river’s current flow, the water depth is just 400 mm. We have a restriction in place now which means the river entrance can’t be used two hours either side of low tide for all vessels and four hours for deeper draft vessels.
He says the ultimate goal of the dredging operation is to increase the depth at the entrance at low tide to 1.5 metres – the point where access restrictions come into effect. “That could take a number of weeks to achieve, depending on river flows and whether or not we have any significant heavy rain events to
help flush the sand at the entrance away.”
Council staff are aware the annual whitebait season opens in two weeks, and aim to have the operation completed before 15 August.
“We’ll monitor the situation closely and adjust the dredging operation to suit,” Mr Tait says. “Clearly, the safety of people using the harbour entrance has to be our first priority, but we are aware of the importance of the whitebait season to our community and we’ll do our utmost to limit any impacts.”
The Council’s operative resource consent allows the dredging operation during daylight hours only.