The full-flow effect


A gravity fed reticulated stock water system has brought modern farming practices to a traditional South Otago sheep and beef farm.


Farm owner John Latta says the system means stock stay away from waterways, productivity is increased, and it offers an environmentally sustainable solution. The scheme is hinged on using the natural resources of the farm in a better way.


ohn is a third generation South Otago farmer with ties to the area going back to when his family were sawmillers in the Catlins, milling native timber.His grandfather moved into the farming industry and bought a property in the Owaka Valley in 1945, at the end of second World War.

John's Uncle Syd then farmed the property until John's Dad Geoff, a stock agent, joined him and the brothers farmed in partnership.In 1973 the brothers bought the neighbour's 750-hectare farm and began farming separately.

From high school John did a stint at Lincoln before returning home in 1981 and spending 37 years on the family farm.The now 60-year old said that after nearly four decades on the farm he 'felt like a rat on a treadmill'. With none of his four sons available to farm at that time he decided to lease the property out.

"For me leasing the farm out is a good set up. My sons all have other things going on in their lives and I commend them for that. By leasing the farm out, I can pursue other opportunities but also retain the farm as an option for the boys in the future.

"The lease arrangement happened quite quickly, and I had already planned to develop the water system. Even though I now lease the farm it is still our property and I could see the many benefits and return a reticulated scheme could offer."



Designing for farm fit

nstallation of the scheme began in the summer of 2018, the same year John leased the farm to Brendan Daly who employs Ben Winter to manage the property. The system design was developed in partnership between irrigation expert Ken Stewart, experienced Te Anau contractor Paul McDonald and John.

The group used an altimeter for heights and elevations, a topography study and maps which, when combined with John's knowledge of the farm and Paul's contracting experience, enabled the design of a scheme that would fit the farm and the requirements.

"We were catching water at 430m above sea level and dropping down to around 120m above sea level so there was a lot of technical and expert advice needed," John says. The gravity fed system provides surety of supply and quality of water and has been designed to accommodate any potential future changes in livestock farming practices.

John says they are blessed with a good water source that is high up on a hill. "Our point of difference is we have a natural spring at height delivering enough flow to drive the gravity-fed system with no pumps or ongoing running costs.

"I had always believed our water source had the potential to feed into a scheme. We have a lot of natural water and ironically, I've spent a lot of time over the years draining the property of springs and bogs.

"We are in a high rainfall area, receiving around 1,200 - 1,500mm per annum, and that is evenly spread throughout the year.

"In my time on the farm we have had a few dry patches but never experienced a drought.

"Prior to the installation we had been existing on natural water with creeks, streams and the Owaka River headwaters.

"We are fortunate the property offers variation from rolling to hill country. You can get a tractor over about 40 percent of the farm with winter feed brassica crops grown, and the rest is tussock and steeper country."



A duplex of water distribution

John ended up installing two systems. The major one supplies 95 percent of the farm, feeding into 110 troughs with a smaller scheme feeding 10 troughs in an isolated corner of the farm.

The major scheme captures water from an underground spring, intercepted about a metre below ground level and then diverted to a settling trough and then into two 30,000 litre tanks.

A labyrinth of approximately 25km of high flow pipes — all underground — distribute the water to troughs in paddocks all around the farm.The spring bubbles up with supply 24/7 — 365 days a year.

"It's like having a big bucket of water sitting high on a hill with a small pipe out the bottom feeding the stock water scheme and the vast majority of the water cycling through and returning to the natural watercourse," John explains. The smaller scheme accesses a spring in a different location that covers the remaining corner of the farm. It runs by the same method using a third 30,000 litre storage tank.

"That gives us cover to have troughs in every corner of the farm."

The amount of water varies depending on prior rainfall, it can drop down to producing 40,000 litres over 24 hours to five times that amount.



Upping the numbers

120 troughs mean that farming practice and grazing is no longer restricted by waterways.

"We now have an ability to have more targeted grazing with the use of subdivision, break-feeding and hot wires based around the troughs which give us a guaranteed water supply, expanding our grazing options.

"The scheme has given us the ability to farm more strategically. The stock are happy, it's great for fattening lambs, great to see them hanging around the troughs on a warm summer's day.

"When I was on the farm, I had 6,000 sheep and 500 cattle, running around 7,000 stock units, but reticulated water means we could now increase our stocking numbers or stock mix.

"Under the new arrangement it is great to see a young manager farming with fresh eyes and because of the surety of the water supply, he is able to comfortably carry more stock and have more grazing options.

John says the scheme has involved a bit of fine tuning. The bulk of the pipework is 63mm thick, futureproofing the infrastructure, should the property become solely beef or even elephants.

1,000 litre break-pressure tanks are installed at every 50m of elevation descent, 13 in total, to manage the water pressure to the troughs.



Prioritising water health

"We try to do things the right way and so it was important we were doing the most we could for the environment. Installing the water system keeps stock away from the waterways and instead gives them access to clean pristine water that is reticulated all around the farm," John says.

"We weren't forced to do this it was a choice. There has been a lot of talk around waterway health and the quality of our natural water sources with stricter water plans and tighter controls happening now and inevitably in the future.

"I considered the health of our waterways, before we put the system in, to be pretty good, and this scheme shouldenhance that further. Our streams have rocky bottoms and are fast moving. They had lots of aquatic and fish life which from a layman's perspective indicates the waterways were in good health.

"The practicalities of fencing off all our waterways are prohibitive, we've got bush gullies and natural bush surrounding creeks and streams, some very steep country and it would be impractical to fence those off, particularly to sheep, so this was our way of doing what we could," John emphasises.

"Installing the scheme meant predominantly stock are going to go to the troughs to drink and are staying away from the waterways so we feel we are contributing to the environment."



A worthwhile investment

John is still involved with the farm and has carried out a lot of capital development in partnership with Brendan and Ben. "Key to us is to retain the farm as a family asset and to know it's being well taken care of by the lessee, which it is.

"I maintain my agricultural interest, but I don't have the daily grind of being on the farm," John notes. John also owns a couple of smaller blocks that he farms, 30ha near Dunedin and 6ha near Owaka, plus rental houses, so is kept busy with property development and management.

John says installing the system was a significant investment, but one that he believes has been very worthwhile."Productivity is up, and we have added value by investing in infrastructure on the property. Plus, we have future proofed our water sustainability."

I am confident the scheme will well and truly pay for itself in the long-term."Some operators would focus on the increased efficiency and short payback time but for us, you can't put a price on the fact that we felt we were doing the right thing."


Economics of hill country schemes

An AgFirst report prepared for MPI, MBIE (Ministry of Business, Innovation, and Employment), Te Puni Kōkiri, and Beef + Lamb NZ published in 2017, investigated the benefits of installing stock water reticulation systems on hill country farms throughout New Zealand.

Benefits included:

  • An increase in stock units per hectare
  • Increased animal productivity
  • Better grazing management
  • Greater pasture production
  • Better environmental outcomes
  • Greater ability to implement farm environment plans
  • Increased drought resistance

Financial analysis showed:

  • An average rate of return of 45 percent over 20 years
  • An average payback period of 3 years.

The report was based on results from 11 case study farms around the country.