Held on Rupert Handyside’s farm just out of Masterton, the day began with Handyside talking about his nine-hectare storage pond, including a project description, planning requirements and some of the challenges that came with it.
The storage facility took four months to build, due to weather-related delays during construction.
It can hold more than 400,000 cubic metres of water providing Handyside, who finishes cattle and lambs, with irrigation across 128ha of the farm, up to 120 days a year.
GV Electrical’s Gordon Mouldey, who worked on the project, says farmers considering on-farm water storage need to consider future operating costs, the biggest of which is power.
Handyside has a pump-operated scheme, with the pump motors chosen because of their efficiency.
Mouldey says it costs an average of about $290 a day in power costs to run, about $5500 a month at its peak, with an average monthly cost of about $3000.
Water is applied at a rate of 3mm over 24 hours, although that can be increased to 4.5mm if necessary, the philosophy being to apply a small amount of water often.
He says when considering how much water to apply, it’s important to understand soil structure on the farm.
CHB Earthmovers director Justin Neville says one of the biggest unknowns in building a storage pond can be unsuitable material at the site’s location and sometimes it is necessary to cut down before building back up.
He says spending an extra $20,000 to $30,000 extra doing pre-construction investigations and testing can save up to $500,000 at the back end of a project.
Earthworks on Handyside’s project worked out at around $1.50 per cubic metre of water, Neville says, which is one of the cheapest he has been associated with as some have gone up to $6.
Wakamoekau Community Water Storage Scheme engineer Inia Rademakers gave those at the field day an update on the project.
The project team has been gathering information, reports, points of view and input from a variety of people and organisations.
It is on track to submit a resource consent application for the project, which will have a capacity of 19 million cubic metres of water.
Its estimated construction cost is $100 million to $120m, and it will be capable of supplying 28 million cubic metres of water a year at greater than 90% reliability.