9 Oct 2018

Dredging work will begin soon on the lower Ōpawāho/Heathcote River to help lower the risk of flooding in the area.

The dredging is part of Christchurch City Council’s Land Drainage Recovery Programme and will be carried out by contractor City Care between Opawa Rd and the Woolston Cut (an engineered channel).

The Lower Heathcote River

Dredging of the Lower Heathcote River will restore capacity within the channel.

The work below Opawa Road will remove more than 20,000 cubic metres of sediment that has built up since regular dredging of the river stopped in the mid-1980s. 

The river will be closed to recreational vessels such as kayaks and canoes, between Opawa Rd and Radley Park, while dredging is underway.

 Council Land Drainage Manager Keith Davison says it will restore capacity lost after the earthquakes and through ongoing silt deposits in the lower Heathcote River channel.

“By restoring the capacity of the river channel, the risk of properties and streets flooding during heavy rainfall will be reduced, benefiting local residents and those who live further upstream.

"There will be some disruption while this project is carried out but the contractor will minimise that as much as possible and we think the benefits to residents in the long-term will be valuable.

“The dredging will also remove contaminated sediment which has entered the river from commercial and street storm water run-off, improving in-stream habitat in the river. This will complement benefits from the new storm water filter being built nearby on Richardson Tce.

“We’ll be planting native trees and plants during the landscaping phase following the dredging work which will enhance the ecological and landscape values of the area.”

The project will be carried out in two stages. Stage one, between Radley St and the Woolston Cut, will begin with some tree removals from riverbanks this week before dredging with an excavator and barge starts at Connal Reserve in mid-October. Work on this reach below Radley Street will continue until June next year, including tidying up the site and landscaping from April.

Walkways on both sides of the river will be closed during some periods of the work, with safety fencing and signage in place.  Access will remain open through Radley Park and to Laura Kent Reserve through Laura Kent Pl. 

Stage 2, between Opawa Rd and Radley St, will also start  mid-October with dredging by an excavator based on the Clarendon Tce side of the river.

Dredging on the Stage 2 reach will be split into two phases to minimise the impact on inanga (whitebait) during their spawning season of March to June. It is expected to be complete by September 2019.

There will be some parking restrictions and traffic disruption, including single-laning, on Clarendon Terrace while trucks are being loaded. Residents are asked to keep children and pets at a safe distance from the worksite and construction machinery while the project is underway.

Investigation and design work for the Stage 3 Reach from Opawa Rd to Hansen Park is underway and dredging of this section is expected to happen in late 2019 through to early 2020.

A map showing where the dredging work will be carried out.

This map shows where each stage of the dredging work will be carried out.