Avon Temporary Stopbanks Reports 2011-2019

Here are four reports that the Christchurch City Council received from the multinational technical professional services company GHD in response to an invitation to tender (LDRP507). The contract for Stopbank Management was eventually awarded to Geotech Limited on 10 March 2017.

The first is an addendum to a risk assessment report from March 2016.  We do not have the full report, but this was probably commissioned in late 2015.
2016 March 6. Addendum to Avon River Stopbanks Risk Assessment March 2016 copy

The second document is a Stopbank Levees Risk Assessment from September 2016 (188 pages).
2016 Sept GHD FINAL Temporary Stopbank Management and Interim Stopbank Strengthening – Risk Assessment – GHD Report September 2016 copy

Document No. 3 is a Stopbank Management Detailed Design Report (247 pages).  Among other things, it includes design standards and criteria, hydraulic modeling, stopbank design, specifications, project risks and consent applications.
2018 Dec 000 GHD Dec 2018 LDRP 507 Avon Temp Stopbanks Detailed Design Report_Final Issue 2018 copy

The final document is a design statement for upgrade and reconstruction of stopbanks along approximately 93 sections of the Lower Avon Estuary

This is dated 14 May 2019.
2019 May GHD Design Statement on stopbanks LDRP 507 Temporary Stopbank Management – Stopbanks Design Statement – GHD DELIVERABLE 16-5-19 copy

The public was never informed about the Request for Tenders or the contract award. It is therefore difficult to understand the activities of the Christchurch City Council over recent years. There has been a series of “community engagement” exercises through Regenerate Christchurch, then the How Team, and most recently, the Coastal Futures team. The latter has held workshops, drop-in sessions and canvassed local residents’ opinions on protection against coastal hazards in the South Brighton area. Yet all of the technical information on stopbank maintenance and repair appears to have been obtained several years ago from GHD, Geoconsult and the other companies that responded to the invitation to tender. None of this information has been made public or communicated to residents in the affected areas. Council staff have also told us that the Tonkin & Taylor 3 Hazards report will not be released until the Adaptation Planning Project, an undertaking with no commencement date and no conclusion date, is underway.

Local residents have invested personal time and effort in meetings and discussions with these groups. So what have been the Council’s intentions with its “community engagement” activities over the last four years?

The following reports from SCIRT dating back to 2011 are also available upon request. email: Hugo.k@empoweredchristchurch.com
Lower Avon Stopbanks Engineering Review Volume 1 Appendix E – Flood Maps.PDF Lower Avon Stopbanks Engineering Review Volume 1 Appendix B – Ground Acceleration Plan.PDF Lower Avon Stopbanks Engineering Review -Volume 2 North – True Left Bank.PDF Lower Avon Stopbanks Engineering Review Volume 1 Appendix J – Risk Assessment Maps.PDF Lower Avon Stopbanks Engineering Review Volume 1 Appendix C – Lab Testing.PDF Lower Avon Stopbanks Engineering Review -Volume 2 South – True Right Bank.PDF Lower Avon Stopbanks Engineering Review Volume 1 Appendix H – Stopbank Construction Form Drawings.PDF Lower Avon Stopbanks Engineering Review Volume 1 Appendix I – Settlement Monitoring.PDF Lower Avon Stopbanks Engineering Review Volume 1 Appendix A – Liquefaction Plan.PDF Lower Avon Stopbanks Engineering Review Volume 1 Appendix K – Seepage and Stability.PDF Lower Avon Stopbanks Engineering Review Volume 1 Appendix F – Risk Register.PDF Lower Avon Stopbanks Engineering Review Volume 1 Appendix D – Condition Assessment.PDF Lower Avon Stopbanks Engineering Review.PDF Lower Avon Stopbanks Engineering Review Volume 1 Appendix G – Concept Design.PDF

Please note that since 2018, tidal measurements from council confirm tides to be substantially higher than when most the above reports were produced.

Ref: https://ccc.govt.nz/environment/water/coastal/2018-tidal-data/ 

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