22 November 2022:
The Redoubt Reservoir project on behalf of Watercare in Auckland has achieved a milestone; the first of four floor slab pours for the new reservoir.
The 8,200m2 was poured in four sections at night, mitigating the risk of the concrete drying too quickly during the heat of the day, and avoiding peak traffic for the ten concrete trucks-per-hour delivering concrete from Stevenson Aggregate.
The reservoir is 106m long, 77m wide, 8m high and will have of 650 tonne of steel reinforcing. Its 45 million litre capacity will bring the total capacity of the Redoubt Road complex to 120 million litres when the project is completed in March 2024.
The reservoir complex was initially constructed in 1973 to provide up to eight reservoirs. Currently, two reservoirs are in service, providing 80% of Auckland’s water demands.
To help reduce the carbon intensiveness of the new reservoir, the project team has partially offset carbon emissions by adding fly ash to the cement mix. The fly ash also has greater workability and robustness, reducing shrinkage cracks compared to other water-based cement mixes.
The clay fill from site has been taken to Puketutu Island, where Fulton Hogan is helping Watercare rehabilitate volcanic cones that were quarried in the 1950s.
