Water for the future

Words: Mary O'Callaghan

Images: (c) ECONNECT COMMUNICATION

The Managing Climate Variability (MCV) R&D Program has been working with Australian primary producers and natural resources managers to deal with our country's changing climate for more than 20 years. It aims to provide better seasonal outlooks and practical climate tools and products, as well as case studies of farmers incorporating climate-risk information into their business decisions.

The farmers profiled here are participants in MCV's Climate Champion program. As such, they have been able to talk directly with researchers about the unique climate-related challenges in their businesses and access the tools they need to manage their climate risks.

The program is supported by the Grains Research & Development Corporation, Meat & Livestock Australia and the Cotton Research and Development Corporation.

LYNNE STRONG, DAIRY FARMER, NSW SOUTH COAST

More milk with less water

Lynne Strong runs 450 dairy cows on two properties in Jamberoo, near Kiama, on the south coast of New South Wales. With average annual rainfall of 1500-2000mm expected to continue into the future, she is well positioned to prosper.

"Climate models show that climate change is going to result in a more favourable weather pattern for this area," Lynne says.

"We're expecting slightly warmer temperatures and more stable rainfall. We're looking forward to this predicted future but, like many other areas in Australia, over the past 30 years we've experienced more extreme weather events. Getting 10 inches of rain in 12 hours and five summer days in a row over 40°C are now common occurrences."

Lynne has used her experience of these extreme weather events to fine-tune the way she manages her business. "We've found that by using climate change strategies we've achieved considerable on-farm efficiencies," she says. "They help us to use our rainwater more effectively and they make good environmental and economic sense."

Half of the water used in the business is used in the dairy and Lynne recycles most of it. "We use recycled water to cool the milk before it goes into the vat and to operate the hydraulics for the entry and exit gates," she explains. "We've also created an effluent reticulation system fuelled by the water we use to wash down the dairy. We irrigate 6ha of farmland with it."

These strategies have helped Lynne's dairy farm become one of the most water-efficient in Australia, producing 125,000L of milk per megalitre of captured water, which is 35 times the industry average.

Lynne has also installed off-stream gravity-fed water troughs in all paddocks and fenced off all waterways, which has improved water quality for the cows and the wider catchment and reduced erosion.

She has optimised pasture growth rate, energy content and yield, which allows her to run four to five cows per hectare (twice the industry average). This also improves water quality, because good pasture cover means less nutrient run-off during periods of heavy rain, she says.

"We can't control the weather but we can control how we prepare for it. For us, that means having optimal soil fertility, good pasture cover and healthy cows."

ROBERT QUIRK, SUGAR CANE PRODUCER, NORTHERN NSW

Growing sugar cane on a flood plain at sea level

Robert Quirk grows about 100ha of sugar cane on a flood plain in the Tweed Valley in northern New South Wales. His farm is only half a metre above sea level, so drainage is his biggest challenge. As the sea level rises the floodwater has less gradient to run off.

"Natural drainage is disappearing for us," Robert says. "For every centimetre the ocean rises we have to pump another 10 Olympic swimming pools of water off the farm. If the ocean continues to rise at about 1cm a year my farm probably has 30 years left to grow sugar cane. After that, with technology, who knows? The size of the pumps that would be required to stay in business just won't happen."

The problem is compounded by changing rainfall patterns. Scientists have told Robert to expect longer dry periods, broken up by bigger rain events, which is how 2015 unfolded. "We can deal with small rainfall events of about 200mm," he says. "But if you put another 300mm on top of that, it's massive. It just kills everything.

"You need enough rain but a lot of sunshine to make sugar. If the cane's growing a lot it's not making sugar. Heatwaves are great-the hotter the better for us. Any temperature in the 30s is ideal."
New cane can be planted in dry soil, where it can lay dormant until the rain comes. But it can't sit in water.

"After six days in water you lose 2.5t/ha of yield per day, so losses can be massive," Robert explains. "It's very difficult to recover from flooding."

Planting on 20cm mounds and working only the top of the mounds is a strategy that Robert uses to deal with the wet. He says it's taken him 10 years to get it right.

"Twenty centimetres mightn't sound like a lot, but it gives us about another 200mm of drainage," he says. "Some people worry that the cane's going to fall over because it's so high, but not so!

"With a changing climate and rising sea levels, drainage in this area will not be the biggest thing. It will be the only thing."

MARK AND ANDREA HANNEMANN, CROPPING/SHEEP ENTERPRISE, SA

From 40 dams to one

Mark and Andrea Hannemann run a mixed cropping/sheep enterprise in the central Eyre Peninsula in South Australia. With 400-425mm average annual rainfall, the 40-odd earth dams on their 2400ha property used to satisfy their water needs. But that has changed as their farming and weather patterns have changed.

"In the 25 years that we've been here our rainfall has decreased by 10 per cent," says Andrea. "In summer we've always had thunderstorms coming through, but now there are more, and bigger, summer rainfall events. We're also having hotter summers and there seems to be more heatwaves. In January 2015 we had 10 consecutive days over 40°C, which is a record."

With no access to mains water in the area, the Hannemanns had to increase the amount of water they cart in.

"We had $11,500 of carting costs a year; $10,000 of that was the trucking cost and $1500 was the cost of the water. It was highly unsustainable."

Instead of adding more earth dams, they developed a water-harvesting scheme to collect water. The scheme comprises an 80m x 40m catchment area that gravitates downhill to a covered 30m x 30m holding dam, both of which are lined with 1mm high-density polyethylene plastic to capture all run-off and prevent soakage. The 3m-deep dam holds 1.5 million litres and is covered to prevent evaporation. Recycled tyres sit on top of the plastic to keep the wind from lifting it.

"The holding dam can gravity-feed the water right across our farm, all the way down to our house 4.5km away. This eliminates the need for pumps. We're going to have feeder troughs to all the paddocks, so when we graze off our stubbles we'll have access to water in each of those paddocks."

Because the holding dam is covered, no algae grows in the water.

"The water quality is amazing," Andrea says, "and if you've got healthy water you've got healthy stock.

"Even your spraying is more effective if you have good-quality water. We believe, through the introduction of this scheme, we now have reliable water for the next 25 years. We're hopeful going into the future."

CLIMATE CHAMPION PROGRAM

For information about Lynne Strong, Robert Quirk and Mark and Andrea Hannemann, or other participants in the Managing Climate Variability Climate Champion program, visit website.