From dangerous drain to superb swale

Laying pipes in the drain

Laying pipes for the project at the Vicarioli property.

By Neroli Roocke

This is the story of how a Far North Queensland couple has turned a hazardous, eroded, two-metre deep and two-metre wide gully into a carefully engineered drainage swale.

It was surprising to hear a grower with an average farm rainfall of around 7000 mm a year say he missed my phone call because he was turning on an irrigation pump.

But Ray Vicarioli wasn’t watering sugarcane on his Bartle Frere property, he was watering grass. Getting it to grow is the final step in a drain rehabilitation project to which the Australian Government’s Reef Programme contributed a third of the cost.

It took Ray and his wife Rosemary two weeks of solid work to re-form the 120m long drain which catches water from a 22 hectare area, including part of their farm and neighbouring cane and banana properties, and channels it into a natural watercourse, called Menzies Creek.

“Before, all the water from these paddocks all ran down the centre here and kept scouring it out. From the top section now it will run through a pipe and of the rest, a percentage will soak in and the rest will flow over the top,” Ray explains.

“It was so deep before, over two metres, that I had to have a ladder in there to climb up and down while we were working on it,” Rosemary laughs.

Together they laid 24 pipes to take most of the water flowing down the gully. These were covered with sand before seepage pipes were laid over the top to take the water flowing down the adjacent cane fields.

“I made my own seepage pipes out of ordinary drain pipe and put the slits in myself – and it works really well,” Ray says. “It’s cheaper and they don’t collapse when you fill in around them.”

“It’s also had a series of layers of gravel, sand and dirt put in with weed matting on top. I worked out there were about 48 trailer loads and five massive truck and dog loads of gravel, dirt and sand. All up it’s probably 300 cubic metres of material that’s gone into there!”

The final step was the grass seed and because of the dry winter, Ray has borrowed irrigation equipment from a banana-growing neighbour in a bid to get it established.

In the end, a wide grassy depression will replace the dangerous two-metre deep gully.

“Once this grass is established, some of the water will still run over the top of it but the soil is protected,” Ray says.

“Red soil can be very slippery and this drain, when it was all open and deep, was a hazard that the bin tractors or the harvester could slip in! It had become a safety issue as well as a water issue.

“They’ll be able to drive straight across once I plant the two blocks on either side with the same variety. It makes it more efficient for the harvester driver as well.”

A final, lower rocky silt trap catches any surface water that remains before the junction of the drain and the creek.

“If there’s any silt coming through the pipes it’ll be caught in the last bit behind a log before the water goes into the creek,” Ray says.

The project extends some work Ray did with his father further up the hill some years ago and he believes there should be more emphasis on projects such as his within the Reef Programme in such rainfall areas.

“I’ve tried over the years, and spent a lot of money, to rebuild headlands to control each paddock’s water within itself,” he says.

“When the rain comes down, it comes pretty quickly. We can get three or four inches (75-100mm) in an hour and if you get an accumulation of water, that’s where it picks up speed and causes erosion.

“I think that silt control and containment and relevant earthwork projects should have a higher priority rating in the grants process because silt has been targeted for pesticide and nutrient run off in waterways.”

Further downhill from the re-formed drain, along the creek bank and by the side of the farm track, Ray has built up a small, 50cm levy bank. His aim is to filter any water flowing off those lower cane blocks towards the natural creek.

“Any runoff from the paddocks basically sits there and slowly seeps through,” he explains. “Trash blanketing too does a great job of holding the water back so very little silt is getting through now.”

The Vicarioli farm is more than 121 hectares with around 110 ha under cane. Creek lines have been progressively planted with trees and while we talk, Ray and Rosemary pull out their Field Guide to Australian Birds book to identify a newcomer. It is a Common Koel, or rainbird, that’s flown down from Papua New Guinea and something they’ve not seen so close to their house before this year.

Some of the tree planting has been undertaken with their local Russell River Landcare group and five acres of steep ground has been kept covered with rainforest species.

Also on the property, Ray hosts the variety distribution plot with new varieties are planted in trial blocks. They’re slow to get going this year and it’s hoped some rain soon will kick them along as well as test out the revamped drainage channel.