Heathcote River work proposed

The Christchurch City Council plans to remove 63 trees from a

2.5-kilometre stretch of the Heathcote River as it works to stabilise the banks to reduce flooding.

The trees will be replaced by

122 new trees as the work is completed.

The council has launched public consultation on its plans to stabilise parts of the riverbank from Ashgrove Tce in Cashmere to Palatine and Eastern terraces in Beckenham.

The consultation document shows 35 healthy trees and 28 unhealthy trees will go to allow the work to proceed. ‘‘The intention is to retain and protect as many healthy and structurally sound trees as possible and increase the existing tree cover within the area,’’ the document said.

It said tree removals would be limited to unhealthy and structurally unsound trees wherever possible, but in some locations the extent of the work meant healthy and structurally sound trees would need to be removed.

‘‘Trees provide significant landscape and ecological values to the waterway and many of the existing trees are providing benefits to bank stability through their roots.’’

The stabilisation work is stage one of two that will eventually stretch further down the river. Stage one has been broken down into 16 sections with varying solutions for each, depending on the riverbank.

Most solutions include a rock edge to protect against bank erosion and undercutting.

Small pipes would be laid into the rocks to provide habitat for aquatic life and riparian planting would overhang the rock edge to provide shading and habitat for aquatic life and to improve stability, the council said.

A report discussed by the council earlier this month said the stabilisation work could impact upon inanga (whitebait) spawning areas, but aquatic ecologists considered the risk could be mitigated. The stabilisation work is part of a $72 million scheme to reduce flooding along the Heathcote River.