Matapouri Beach is in line for sand replenishment work. Council is planning to take sand that has become trapped in the estuary and put it back on the beach, mimicking a natural process that has been restricted since the road bridges went in many decades ago.
Parks manager Sue Hodge said the proposal is very similar to the successful replenishment project undertaken in 2007 and incorporates several ‘lessons learned’ from the earlier project.
She said coastal erosion is a natural process that has always occurred at Matapouri Beach, with storms washing sand from the beach and into the estuary. “But before the area was developed, floods would flush sand out of the estuary and it would settle again in the bay – there was a natural equilibrium between the estuary and the beach," Sue Hodge said.
“When roads were built across Te Wairoa and Parangarau Streams, the bridge abutments narrowed the stream channels and confined flood flows, reducing the amount of sand flushed back into the bay”.
As a result, more and more of the beach sand started clogging up the estuary.
“Our aim is to take up to 15,000 cubic metres of sand out of several spots in estuary, transport it to the beach via Matapouri Road and Te Wairoa Street, place it and re-contour the beach,” Sue Hodge said.
“We do not want to impact the ecology of the estuary so we have engaged a highly-experienced ecologist to produce an ecological report. We will not be excavating below the low tide mark, instead taking the sand above that level that has fewer species living in it. Areas with sea/eel grass present will be avoided”.
This work will create more useable beach area when the tide is in. It would also protect council and private property against coastal erosion. The sand replenishment should last for about 10 to 15 years, depending on how many big storms we have in that time.
“At the same time as we add the sand to the beach we would improve pedestrian access and put in lots of dune plants. This would include installing some steps to protect the plantings,” Sue Hodge said.
“But before all this goes ahead, we are meeting with the community to discuss the project, then lodging a resource consent application to ensure we are complying with the RMA. If that all goes smoothly we may start work in October and the job should be done before Christmas".
Local consulting firm Richardson Stevens Ltd (now known as RS Eng) performed the cost-benefit analysis and provided the engineering design for the work. Due to the complicated nature of the project, the engineering design was then peer reviewed by Labonte Coastal Consultants Ltd (Waipu).
A public meeting will be held on Sunday 8 July at 3pm at the Matapouri Hall.