O’Connor, K. F. (2009, December). How and why Christchurch City Council and the community should clean up McCormacks Bay. McCormacks Bay Steering Group.
The McCormacks Bay Steering Group (MBSG) was formed in 2005 following calls from the Christchurch City Council (CCC) and the Avon-Heathcote Estuary Ihutai Trust to develop a comprehensive planning approach to the inter-related issues of replacing the central culvert in the McCormacks Bay Causeway, sea wall repair, and the rehabilitation of McCormacks Bay. As described in their 2006 charter, the required outcome of the steering group was to develop a report based on collaborative research with the CCC which made recommendations on design scenarios for the culvert replacement, associated natural and recreational values of the Bay, and further required investigations.
Published in 2009, this document is the resulting report envisaged by the MBSG charter. Despite stating a potential need for further investigation and reporting based on recommended ongoing work, the steering group was able to conclude that long submergence in standing water due to ineffectual drainage was at the heart of ecological issues in McCormacks Bay, including declines in estuarine benthic fauna, algal blooms, and anoxic decomposition. To remedy this, the group proposed that a culvert design at the lowest possible invert level was likely to provide the best outcomes regarding tidal filling, bay draining, and kayak use. They also integrated its findings and recommendations into a series of twelve steps to be taken by the CCC to create a clear, economically viable, ecological vision. These steps can be found on page 11 of the report.