The Whakatāne District Council has reluctantly accepted advice that the planned channel deepening and widening work on the urban section of the Wainui Te Whara Stream should be delayed until mid-October to avoid potential weather-related issues with bank stability and revegetation.

The channel works are the second stage of a major project designed to increase the stream’s flood flow capacity by 60 percent — from 20 to 32 cubic metres per second — and reduce the likelihood of overtopping and property damage in extreme weather events. 

Mayor Tony Bonne says the Council’s intention had been to start the channel works in February and complete the project before winter sets in. “That timing was dependent on the necessary resource consents being finalised, but unfortunately, the geotechnical complexities of the planned work have delayed the consent process.

“We are now awaiting final sign-off of resource consents by the consent authorities — the Bay of Plenty Regional Council and Whakatāne District Council — but even if the channel work commenced immediately, it would not be finished until well into winter,” he says. “That would have created a number of potential risks, including issues with bank stability due to the likely wet ground conditions, and slower revegetation of the banks while the cold winter temperatures prevail.”

After discussing the matter at yesterday’s Council meeting, elected members acknowledged the need to delay the project until spring, when construction conditions will have improved.

“Work will not be able to commence until the whitebait season ends on 15 October, but we intend to have everything in place so that this key flood protection project can then proceed without further delay,” Mayor Bonne says.

Upper catchment works were completed in 2015 to regulate rain run-off into the stream. Culvert and bridge upgrades on the urban channel section were also completed in 2016, as part of the first stage of the Wainui Te Whara flood protection project.

“While those are both positive factors, the channel regrading works clearly make the biggest contribution to improving flood protection in the urban area, and Council elected members and Infrastructure staff are extremely disappointed that we have not been able to proceed in the timeframe we had targeted,” Mayor Bonne adds. “In the meantime, all possible channel maintenance work will be undertaken, so that the chance of channel overtopping is minimised, and we’ll be closely monitoring the situation through the wetter winter months.”