In a farm streambed in the foothills of Mt Pirongia, a "thwump thwump thwump" sound is accompanied by fountains of water spraying out of a pump with mechanical regularity.
Engineer Kevin Smith and his right-hand man Mark Rickerby are tinkering with it, experimenting, to see if they can make it more efficient.
"Just recently they've been coming out a fair bit," says farmer Michael Kent, who owns the land and the pump.
It's called a rampump, which in itself isn't an original invention. But Smith says it's the most powerful rampump design in the world, and it can change lives.
A rampump operates without electricity. All it has is a pipe entering the pump, two valves, and a pipe running out.
It uses kinetic energy generated by water going down a small drop, and forces a smaller amount of water up a much larger slope. The excess water fountains out and runs back into the stream.
Smith, who owns the rights to this particular pump design, says his rampumps leave others for dead.
"There's people pumping up to 200 feet and they think that's a long way; 200 metres is nothing for us."
In fact, there's one in Kaikoura that rams the water up 420m of elevation with 600psi of pressure.
Kent's farm pump only has to elevate the water 60m, but it's been moving 51,000 litres of water into the farm storage tank every day for the last 16 years.
The pump, called the Williamson Hi-Flo Rampump, was designed by Hamilton man Owen Williamson who ran the business until Smith bought him out about 10 years ago.
"Owen's a genius type inventor, a mad type inventor. And I say that affectionately," says Smith.
Smith was running his father's steelworks business in Ngaruawahia building horse trucks when he was introduced to Williamson. He saw an opportunity to move the business into a different market and took it.
"When I took over the rampumps the horse trucks were our primary business. Now we're pretty much 100 per cent rampumps. And it's just going to keep on growing. The potential is just huge."
There are more than 2000 Williamson rampumps operating in New Zealand, and Smith expects to install another 40 this year.
He acknowledges that selling them is hard work and time intensive. Each site requires about two days of surveying and calculating before installation can even begin.
Smith says the second biggest pump he sells costs $10,500, and could easily save a farmer $6000 a year in electricity.
"Effectively this pump pays for itself. It's as close to perpetual motion as you're ever going to get."
Though he's busy running around the countryside in New Zealand surveying and installing pumps, Smith wants to take them to the global market.
"We get correspondence daily from all around the world," he says. "Our big push at the moment is to go into Latin America."
Up until now, Smith and Rickerby were manufacturing and installing the pumps themselves, but they recently signed a deal to outsource manufacturing to two Hamilton companies.
The plan is for Rickerby to take over the New Zealand operation while Smith pushes sales overseas.
He spent the first two months of the year in Panama, Costa Rica and the United States.
There are already a few Williamson rampumps overseas, with some notable examples in far-flung Cambodia and Vanuatu.
Smith installed the Vanuatu pump in a village called Epule in 2011, funded by aid money from the New Zealand and Australian governments.
Smith says about 500kg of equipment was carried on foot through the bush to the village, but it was worth the effort to "completely alter" the lives of the locals.
"When I left they had running water in the village."
An American businessman contacted Smith to install the pump in Cambodia. That businessman is now living in Panama, and is working with Smith to broker deals in South America.
"We're looking at 70 to 100 units initially to go in there," says Smith.
He wants to market to farmers and remote communities, but no sales have been made yet.
"I'll be back up there towards the end of this year," says Smith.
- Waikato Times