The Christchurch City Council will spend an extra $3 million on an intersection redevelopment to protect a threatened fish species.
A drain running parallel to Marshland Rd is currently a breeding site for the vulnerable lamprey species. The City Council plans to put traffic lights at the Slow Styx, Marshland and Hawkins roads intersection and widen a bridge about 50 metres north of the intersection to protect them.
Council project manager Adrian Thein told Fairfax the lamprey couldn't be moved because of its threatened status.
"If we do any physical work that impedes the lamprey then the Council will be liable."
This pushes the original design's $7.4 million cost to around $10.6 million. It's said the original design would have damaged the drain and impacted on the lamprey.
The Council's Infrastructure, Transport and Environment Committee is in support of the new design.