Council to trial new approach to bank maintenance

Some of Christchurch’s grassy riverbanks will be left uncut on a trial basis for environmental reasons.

Normally the grassed banks of the city’s waterways are kept closely mown but the West Melton Zone Committee, Environment Canterbury, and Fish and Game have all raised concerns about the impact that may be having on the ecology of the rivers.

They are concerned that closely shaving the grass on the riverbanks could be increasing the risk of erosion, damaging the riparian habitat, and reducing an opportunity to filter contaminants from run-off into the rivers.

Christchurch City Council Land Drainage Manager Keith Davison said the Council had assessed the need to mow the banks in light of the concerns raised and had decided to stop grass cutting between the waterway and the top of the banks in the middle and lower reaches of the Avon and Styx Rivers.

It had also decided to stop grass cutting between the waterway and the top of the banks within trial areas of the Heathcote River and Steamwharf Stream.

“Our plan is to monitor the impact and use what we learn to make a decision about whether we permanently cease mowing the banks. This is not about saving money; it is about doing what is best for the ecology of our waterways,’’ Mr Davison said.