24 Jul 2018

The first stage of a major bank stabilisation programme to reduce the risk of flooding from the Heathcote River is nearing completion.

The 2010-11 earthquakes – coupled with natural erosion – caused the banks to slump, reducing the river’s capacity to deal with heavy rainfall.

Christchurch City Council Land Drainage Manager Keith Davison says the first stage of the stabilisation work is on track to finish by the end of July, followed by landscaping in early August.

Bank stabilisation alongside the Heathcote River.

Bank stabilisation work along the Heathcote River.

“The stabilisation programme aims to increase the capacity of the Heathcote River and reduce the impact of flooding in the area,” Mr Davison says.

“Stage one covers two kilometres, stretching from Ashgrove Terrace in Cashmere to Palatine Terrace and Eastern Terrace in Beckenham.

“We have lined the riverbanks with rocks, while rock-filled baskets (gabion baskets) line a further 270 metres. Where we can, we have also widened the channel to further increase river capacity.”

To support the stabilisation work, 63 trees are being removed. These will be replaced with 122 new trees along the riverbanks.

The Council is now calling for feedback on plans – including landscaping – for stage two of the project, covering Waimea, Eastern, Palatine and Riverlaw terraces in Beckenham.

Stage two is scheduled to start in October-November.

It is proposed that a further 1500 metres of riverbank be lined with rock and 65 metres with gabion baskets. Extensive landscaping will complement the work.

The project is expected to be completed by mid-2019.

Both stages are part of the Land Drainage Recovery Programme to reduce the risk of flooding and to improve waterways affected by the earthquakes.

Spreydon-Cashmere Community Board chairperson Karolin Potter is urging local residents to “have a say” on the plans for stage two.

“Natural measures to lower the flood risk provide the best solutions,” Ms Potter says.

“The stabilisation work is an integral part of the recovery programme. The work on stage one lays the base for the greater protection of our local community.

“Council staff from many disciplines are also working hard to support the river’s indigenous flora and fauna.

“It’s important that we now add our voice to plans for stage two to help shape and strengthen the area for generations to come,” she says.

Stage two submissions close on Wednesday, 1 August.