Flood scheme costs in
A report to Future Tairawhiti outlined an estimated cost for the improved design of the Waipaoa Flood Control Scheme that was granted resource consent at the end of October 2018.
An independent peer review of hydraulic models prepared for the consent resulted in an increase in the stopbank design requirements.
The design required stopbanks to be increased by up to 1 – 2m in some areas compared to 1m as originally indicated in the 2017 consent application.
Four waters infrastructure manager Neville West said in the report with the higher design heights there is an associated 40–80% increase in the volumes of material to be transported and compacted to form the new stopbank. This translated to a 25%-45% increase in estimated cost.
The current project budget is $23.4m which spans a 15-year period. The increase in design height adds a further $6m to $11m to take the new total estimated project cost to $30m to $35m.
Council accepted the recommendation to evaluate the additional budget as part of the 2021- 2031 Long Term Plan, which will allow estimates to be based on actual tendered rates.
Upgrade work to be completed over the next three years would remain as planned the current Long Term Plan.
Construction of the first 4km of stopbank upgrades is planned to start by February 2019 on the city side of the Waipaoa River between Ford and Ferry Roads, south of Ormond Township.
Cycle trails decision
The provision for cycle trails included in the consent application was declined.
The independent hearings commissioner considered that there wasn’t sufficient detail in the application around the exact extent of the trails in order to determine the scale of effects and mitigation measures required.
Council has decided not to appeal and will seek resource consent when more detailed information can be developed or Council decides to go ahead with the trails.
The inclusion of cycle trails in to the flood control project would add an estimated $3m.
A $6m Provincial Growth Fund application will be submitted to central government for consideration.
Mr West said the PGF application would focus on stopbank and cycle trail works in the area between the Waipaoa Rivermouth and the Matawhero Bridge.