The MP for Waimakariri is asking why an expensive sewer was put through part of his quake-hit electorate which has now been declared a residential red zone.
Maps released on Thursday have divided the city into four residential zones - red, orange, white and green. The red residential zone represents the worst affected area, which cannot be rebuilt on for many years.
Clayton Cosgrove says the $1.8 million sewer was recently laid through the suburb of Kairaki Beach in preparation for the rebuilding of the region after the earthquakes.
Mr Cosgrove says the Government's decision to abandon the suburb came with little warning.
He says the Waimakariri District Council, which built the sewer, should have been told much earlier the suburb was going to be scratched.
One councillor, Neville Atkinson, says the sewer also serves a neighbouring suburb so the work would have gone ahead anyway. But he says if the council had known Kairaki Beach was going to be a red zone, it would have amended the plans.