Kris Croft: Key milestone for Waimea Community Dam

The diversion outlet of the Waimea Community Dam is due to be completed in August, allowing work to begin on the dam’s embankment in September.

The first major dam project in New Zealand in more than 25 years, it is being built by Fulton Hogan and Taylors Contracting for Tasman District Council and Waimea Irrigators Ltd to irrigate the fruit, vegetables, hops and grapes of the Waimea Plains.

A major focus over recent weeks has been ensuring a stable base, ensuring water tightness on rock that is naturally highly foliated (fissured). To this end, a stable grout mix is being injected up to 35 metres into the ground, and the base rock painstakingly cleaned and any loose material removed. Such was the intensity of this process that the rock on which the dam will be built was hand cleaned by a 20-person team at an average of one square metre per person per hour.

“With so many people working on their hands and knees it had all the appearances of an archaeological dig,” Fulton Hogan’s structures manager Matt Loach says.

Due to be completed in March 2022, the dam itself will be 180 metres wide at the base, six metres wide at the crest with an overall height of 55 metres. It will 220 metres long at the top and 80 metres at the base, and the reservoir will hold 13 million cubic metres of water.

Pictured, from left, is construction manager Dean Quickenden, structures manager Matt Loach and Fulton Hogan’s general manager, construction Justin Mcdowell. They are standing in front of the first 120 tonne telescopic crawler GTC-1200 crane in New Zealand, purchased for the project. The JV also has one of the largest excavators available, a 90 tonne Hitachi 890.