Mr Blaikie said they had established at Friday's meeting that the channel was about half a metre too shallow, and not wide enough.
Over the next couple of days they would be deepening the channel with a digger.
They had redirected the channel to run closer to the land, so the digger was able to work from solid ground.
Previously they had put the digger on a barge so it could reach the channel, but Mr Blaikie said this was costing ratepayers about $20,000-$30,000 a year.
Coastguard Wanganui president Kevin McKenna there was not a problem with using Putiki and it probably only added 15 minutes to response time.