Work will begin soon on a project that will reduce flooding risk, advance the Ngā Puna Wai Sports Hub development, and save up to $4.5 million.
The Council has voted in favour of a proposal to extend the Wigram Basin, delegating authority to award contracts for the construction project to the Council's Infrastructure Transport and Environment Committee and the General Manager of City Services.
The $7.25 million project is designed to reduce the risk of flooding to over 100 homes in the upper Heathcote catchment area. It will also help advance the Ngā Puna Wai Sports Hub athletics track development because the two projects will be constructed in tandem resulting in significant cost savings. Work is expected to begin in March.
Savings will be achieved by using excavated material from the proposed Wigram Basin extension at the Ngā Puna Wai Sports Hub site. Ngā Puna Wai will also be able to share stormwater facilities with the Wigram Basin.
These measures will reduce costs by an estimated $2.8 million to $3.5 million for the Wigram Basin project and $1 million for Ngā Puna Wai.
Construction of Ngā Puna Wai Sports Hub is on track to begin in April 2017, with a view to having the athletics track completed by early January 2018 and the other sports surfaces progressively completed from March through to December 2018.
The Wigram Basin is one of four storage sites identified by the council to help prevent flooding in the Heathcote River catchment.
In addition to flood mitigation, there is an opportunity to create a large wetland area at the site to provide treatment for one of Christchurch’s worst waterways, Hayton’s Stream, resulting in an improvement downstream in the Heathcote River. The wetland will provide habitat for a number of threatened species and boost native vegetation.
Christchurch City Council Land Drainage Manager Keith Davison said the Council decision was an example of "joined up thinking" and co-operation that would benefit the community from a sports facility perspective, while reducing flood risk to many residents of the upper Heathcote catchment. "At the same time it offers cost savings to maximise value for money for ratepayers."