In today's Press (here) a geotechnical engineer from Tonkin & Taylor states there are no engineering grounds for reclassifying Parklands as a Red Zone. The same engineer is quoted as saying the land in Parklands is "much better than in the red zones".
This may, or may not, be the case, however there is no conclusive evidence either way. Nothing has been made public about the state of the land under Parklands, nor Kaiapoi or anywhere else for that matter, which would show the truth and substance of the comments.
It is not sufficient to state land is Red or Green on the "trust us we know what we are doing" basis. There is diminishing trust and increasing uncertainty that experts do know what they are doing and saying. The earthquakes and damage done are without precedent in New Zealand. Similarly there is little known about the way the land beneath Christchurch will behave in the future, be that tomorrow, next year, or some years hence. This is not the environment for agencies to be making unequivocal statements without backing them up with supporting evidence. Confidence is needed that a commitment to repair or rebuild is a wise thing to do. In some areas, including Parklands, this confidence is not high.
CERA have said they will revisit the zoning of Parklands. Who will be undertaking the review? Will some external agency review both the data and the conclusions? The Earthquake Royal Commission has been using this approach to peer review reports from witness agencies to ensure what they say can withstand scrutiny. Such a procedure would bring more expertise to bear on the Parklands issue, and credibility to the outcome.
Ultimately the only thing that can remove doubt and suspicion is public scrutiny of both the factual findings made through geotechnical investigations, and the interpretation put on those results.