28 Jun 2017

Residents in the Flockton area can sleep easier next time they hear rain on the roof, with the completion of the key parts of the Dudley Creek flood mitigation scheme.

Saturday saw the final part of the 800-metre bypass installed, to take stormwater from Petrie Street east along Randall and Medway streets to the Avon River.

The Dudley Creek bypass.

The final section of the Dudley Creek bypass has been installed.

More than 500 properties now have increased flood protection from the scheme that was given the go-ahead in August 2015 to restore Flockton and surrounding areas to pre-quake levels of flood risk.

The bypass is one of the biggest in New Zealand and has been built by laying about 500 box-shaped pre-cast concrete pipes end-to-end. The pipes weigh between four and five tonnes each and measures four metres by two metres.

Most of the time the bypass will be dry as it is only designed to be used when there is heavy rain and there is a risk of Dudley Creek overflowing.

"Now, if we have a heavy rainfall we'll be able to divert over eight cubic metres of flood water every second from Dudley Creek to the Avon River," says Christchurch City Council Land Drainage Manager Keith Davison.

"This, combined with all the other aspects of the scheme we've been working on over the last few years, means we can now reassure hundreds of households that their flood risk has been significantly reduced."

There is still work to be done on other aspects of the flood remediation scheme, including Hills Road Culvert and Shirley Stream widening, and road renewal in streets including Randall, Medway and Petrie.

"While we are thrilled that we've met our target deadline to significantly reduce flood risk, we are very conscious that until we're finished all the works, there will still be disruption and inconvenience for people in these areas," Mr Davison says.

"We are working hard to complete the remaining works as soon as possible, and we look forward to celebrating with the whole community when everything is done."

Find out more about the Land Drainage Recovery Programme.