Control erosion on roads and tracks

NQ Dry Tropics Grazing Field Officer Brad Martin (left) and Bowen grazier Dennis Bolton mark out whoa-boys.

Reserve a seat at a workshop

Soil Conservation Officer Bernie Claussen

We’re offering FREE practical workshops to help landholders control erosion on tracks and fence lines.

Workshops will provide land managers with:

  • a better understanding of the cause of water erosion problems on station tracks and fence lines;
  • alternative ways of dealing with water erosion problems;
  • basic surveying skills using a laser level;
  • setting out whoa boys; and
  • a demonstration of machinery techniques for erosion control.

For more information and to register your interest, contact Soil Conservation Officer Bernie Claussen mobile: 0438 223 152  email: bernie.claussen@nqdrytropics.com.au.

Graziers use whoa boys to protect soil

Burdekin graziers are undertaking training for erosion control on property roads and tracks to manage runoff.

Roads on grazing properties are susceptible to erosion because they collect runoff from overland flow, as well as from rain falling on the road surface, producing runoff much faster than the surrounding landscape.

Through its Landholders Driving Change Program, NQ Dry Tropics is hosting free workshops on how whoa boys can be used for erosion control. Whoa boys extend across the road or track, diverting runoff to the edge of the road and allowing it to continue in its natural flow direction down the landscape.

A workshop held on a property at Scottville, near Collinsville, gave local graziers the specifications and construction techniques for whoa boys.

Grazier Kylie Bolton gets some tips from NQ Dry Tropics Soil Conservation Officer Bernie Claussen on how to use a clinometer, a tool that’s used to measure the angle of elevation, or angle from the ground. It can be used to measure slopes for preliminary surveying.

Presenter, NQ Dry Tropics Soil Conservation Officer Bernie Claussen, said an understanding of the landscape and soil types, and how water flowed through the landscape, was key to knowing where to construct whoa boys.

“Water always follows the easiest path and given a choice will flow down a bare road surface rather than through adjacent paddocks,” she said.  

“It runs off the compacted surfaces of roads at much higher rates than it does from the surrounding landscape.

“Failure to manage this runoff leads to erosion either on the surface of the track itself or of the land adjoining it.

“There’s a number of considerations in locating and designing whoa-boys, including soil erodibility, land surface condition and landform, other infrastructure, and existing erosion on the road.” 

Bernie said participants enjoyed being able to apply the theory through practical exercises.

“You can talk theory all day, but it doesn’t mean much until you’re out in the paddock using a level to take readings, calculating spacing on the slope, and checking the direction of overland flow adjacent to the road, to outlet on the bottom side, to make sure you’re locating whoa-boys in the right place,” Bernie said.

“It takes a bit of practice and trial and error, to get it right.

Bowen grazier, Jocelyn Gordon said she took away a few rules of thumb from the workshop.

“Knowing your catchment size and how it influences the speed of water movement across it needs to be taken into account when measuring up for whoa boys,” Jocelyn said.

“Always use a level. We think we can judge by eye, but today proved that’s not the case. 

“Whoa boys start at the top of the slope and are spaced down from there, and constructed from the topside or high slope unless dispersive soils are evident and then they should be constructed from the bottom side to reduce the risk of further exposing these soils.”

Jocelyn said the workshop was a good reminder whoa boys may be required on slopes as gentle as 1 per cent, and that this was sufficient to create an erosion slope.  A slope of 1 per cent has a fall of one metre in 100m.

Scottville grazier Stan Fordham said working with dispersive soils was a challenge and learning about whoa boy construction techniques reinforced this.

“We have a lot of poor soil that’s sodic, dispersive and powdery. All our efforts are geared towards keeping soil on our land and stopping it from going down the creeks and flowing into the Burdekin River,” Stan said.

“The effectiveness of erosion control on a property directly affects the quality of water on the reef.

“Constructing properly functioning whoa boys is another tool in the kit to help us do that. The workshop reinforced how care needs to be taken not to expose dispersible subsoils.

“A source of soil to build the mound for a whoa boy is a sill located at the whoa boy outlet. We were shown how to build a sill as a level outlet, long and wide, to slow the water down and allow it to spread out across the paddock, and infiltrate into the soil.

“If needs be, we will have to source topsoil from elsewhere on the property to make sure we construct whoa boys that will hold in place and don’t need ongoing maintenance.”

Scottville grazier Barry Collett, an earthmoving contractor, who hosted the workshop on his property said he enjoyed the workshop because it combined theory and practice.  

He explained to the group, then demonstrated how he used whoa boys to manage run-off.

“The aim is to take the velocity out of the water flow so it slows down and infiltrates paddocks to promote pasture growth,” Barry said.  

“With velocity, it carries fine sediment, stays suspended in the water and can flow for miles. I’ve got many dispersive soils, so when the rain hits it, it dissolves and goes down the gullies in no time.

“When it comes to whoa boys, it’s all about having minimal impact. You don’t need big machinery. Once land is disturbed, it’s hard to restore it.

“I take the time to work out where best to put whoa boys, and knowing soil type is a major factor. If you don’t know what’s your subsoil layer, such as clay, mixed sand and clay, gravel, or other, you could be in all sorts of trouble.”

Barry carries out basic soil testing across his property, including testing for aggregate strength texture, and assessing water infiltration.

Bowen grazier Dennis Bolton said he enjoyed the workshop because it provided practical insights and an opportunity to learn from other graziers’ experiences.

“It’s important to know the theory but to have that complemented by practical exercises was really good because it embeds it in your mind,” Dennis said.

“I enjoy these types of workshops because it’s about sharing knowledge and experiences from other graziers.

“You always learn something. It was good to learn about the fundamentals and principles of constructing whoa boys, and it was equally good to learn how each property and site is different, and you need to be mindful of that.”

Bowen graziers Brooke, Cody and Jocelyn Gordon undertake basic surveying to take readings and mark out whoa-boys.

Scottville graziers Judy and Stan Fordham, and Barry Collett, centre, undertake basic surveying to take readings and mark out whoa boys.

Outdoor classroom – getting the theory on whoa boy construction techniques and methods before practical exercises.

Bowen grazier Dennis Bolton, left, and Scottville grazier Barry Collett, discuss how the alignment of linear infrastructure such as roads and fences, in relation to the landscape is an important influence on erosion risk.

Grazier and earthmoving contractor Barry Collett, demonstrates how to construct a whoa-boy.

The Landholders Driving Change Program is funded by the partnership between the Australian Government’s Reef Trust and the Great Barrier Reef Foundation.