Waimakariri Flood Protection Nears Completion

Published: 14-Aug-2019

Canterbury will be better equipped to deal with a major flood event following the completion of the Waimakariri Flood Protection Project by Environment Canterbury.

The 10-year $40 million project will come to a close this month, ahead of schedule and under budget. The finishing touches include the installation of a floodgate at Dickeys Road in Belfast.

Construction began in 2010 and featured the upgrade of 35km of primary stopbank along the Waimakariri River, construction of a 25km secondary stopbank, and 8km of rock armour bank protection work.

Environment Canterbury chief executive Bill Bayfield said this project would safeguard the community against extreme weather events in the future.

“The project will protect parts of Canterbury from flooding, which has the potential to cause more than $8 billion worth of damage,” Bayfield said.

“We have seen major floods in the past that have breached the stopbanks of the Waimakariri River and as climate change continues to take hold, we need to ensure the community will be protected.”

The project also aided local biodiversity projects and assisted with the development of recreational assets.

The completed works ensures the primary stopbank will be able to handle a flood of 5,500 cumecs and the secondary system will offer protection against a 6,500 cumec event. The largest flood from the Waimakariri River was just under 4,000 cumecs in 1957.

The Minister of Local Government and Associate Minister for the Environment Hon Nanaia Mahuta said she was impressed with the steps Environment Canterbury had taken to protect the region’s biodiversity building this project.

“It’s heartening to see that they have protected our taonga by mapping rare native plants and animal species and aligning the stopbanks to protect ecologically sensitive areas.”

The project’s impending completion was marked with a ceremony at Environment Canterbury today attended by Nanaia Mahuta, Minister for Climate Change Hon James Shaw and Minister of Civil Defence Hon Peeni Henare.

This article was provided by Environment Canterbury - Learn more about the project

Key facts

  • Construction on the project started in spring of 2010, and is on target for completion in August 2019, ahead of schedule and under budget.
  • The project included the upgrade of 35km of primary stopbank, construction of 25km of secondary stopbank, and 8km of rock armour bank protection work.
  • A total of 700,000 cubic metres of Waimakariri River gravel was used for stopbank construction, and 260,000 tonnes of rock was used for rock bank erosion protection work.
  • There is a retractable flood barrier at Dickeys Road, Belfast, which is unique to the South Island.
  • The completed project works will ensure the primary stopbank has a significantly improved design flood capacity (5,500 cumecs), and that the secondary stopbanking system is able to contain break-out flows from the primary stopbanks during a very large (6,500 cumec) flood.
  • The project also aided a range of local biodiversity and recreational initiatives.