Categories: Articles, Resource managementPublished On: 19th April 2024

Erosion control: Old tyres to the rescue

By 6 min read

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Old rubber vehicle tyres are super useful for controlling soil erosion in natural rangelands.

Nobody likes the look of old vehicle tyres on a landfill or dumped somewhere in a backyard, but Ken Coetzee of Conservation Management Services in George in the Southern Cape makes use of old tyres to successfully contain soil erosion.

Old tyres are cheap to obtain (if not totally free), are basically indestructible, sturdy, and easy to work with. They are especially useful where natural materials such as brush and stones are not plentiful enough to build a barrier against soil erosion. The rubber takes ages to degrade and will not contaminate the environment, so the risk of chemical contamination is very low.

Unfortunately, old tyres are not very pretty to look at, especially in a natural landscape. But that problem can be overcome by camouflaging them with jute geofabric or by simply filling them with gravel, stones, soil, and mulch and planting seeds or seedlings of native vegetation in them.

Barriers against soil erosion

“The use of discarded rubber tyres for soil erosion control represents the innovative repurposing of a problematic waste material,” says Ken.

They can be very useful as barriers in the effort to contain severe soil erosion in wide gulleys where water flow is fast and destructive during a rainstorm.

“The secret to success in the use of tyres is that the construction must be consolidated and robust enough to prevent the tyres from being washed down the gulley during the first rainstorm after construction,” says Ken.

Basic construction principles

The tyres are stacked over iron fencing standards that had been driven deeply into the gully floor and each tyre must be firmly tied to the iron standards.

Tyres are stacked in layers. As the tyres are stacked on top of one another each must be wired to the ones underneath it and to the standard.

Care must be taken to key the construction into the gulley sides at at least a tyre width.

Each tyre must be filled with gravel or stones from the gulley walls and floor before the next layer of tyres is added.

The top tyres in the mid-gulley part of the structure must be at least 200 mm lower than the sides of the gulley walls to ensure the water run-off takes place down the centre of the gulley.

Flat area

Rubber tyres can also be useful in the control of water flow across sheet-eroded areas.

Place the tyres flat in lines across the eroded area. Wire it securely into place to a line of iron standards driven into the ground. (See Figure 1).

The tyre barrier will slow the flow of the water and increase penetration. In addition, sand and organic material will be held in place behind the tyres, helping to improve soil conditions.

The barrier will also check wind-blown sand, plant debris and seeds.

To create protected sites for seed germination, each tyre can be filled with fine mulch. Loosen the soil in the tyres and plant seeds into them before applying mulch.

Head cuts

Tyres can be used to stabilise the head cut at the nick point of erosion gullies. The nick point can be widened so that a single tyre will fit into it. Secure the tyre to steel or wooden pegs driven into the earth. Fill the tyre with compacted gravel or earth. Plant pioneer vegetation into the tyres and cover with mulch. Use compacted mulch, fine brush, or gravel to fill the cracks between the outer tyre wall and the soil surface.

Figure 2: The use of a scrap rubber tyre structure to stabilise a large gulley head-cut.

Other applications

Tyres can also be used very effectively to combat severe soil erosion, as well as for the construction of large check dams in wide gullies, to stabilise head cuts in deeper gullies (see Figure 2), or to stabilise collapsing stream banks.

Deep gulley

To check soil erosion in a deep gulley, create a stepped barrier consisting of layers of tyres filled with soil or gravel. The lower level of tyres can be filled with stones if there are any available, otherwise all tyres can be filled with soil and gravel that is well compacted.

Establish native wetland plants in the tyres, which will further anchor the tyres with their roots once they start growing.

Gravel and soil must also be firmly compacted in place behind each layer of tyres, from the bottom to the top, starting with the widest layer at the bottom and working up to a single tyre layer at the top.

Securing riverbanks

The use of tyres to stabilise a riverbank depends on the manner in which the tyres are secured to stay in position.

Firmly secure the tyres to anchor poles (either wooden stakes or iron standards) that are deeply driven into the sides and floor of the gulley. Wire the tyres to the stakes and the tyres below them and next to them (horizontally and vertically).

This will ensure that the barrier is a rigid and tightly united structure that will not easily be damaged or lost to flooding water (see Figure 3).

When used in gulley erosion control, the tyre structures must provide a notch for overflow in the middle of the structure.

Lining the structure

Lining the tyre structure with geotextile will hold back waterborne silt, organic material, and seeds, which will step up establishment of vegetation that will hold the soil together behind the structure.

Permaculture application

Tyres are also widely used for permaculture gardening, as they hold composted and mulched soil in place, keep the moisture in the soil, and provide some protection from the elements, such as wind and water erosion.

Use them, don’t burn them

Using discarded tyres to rehabilitate soil erosion is a much better option than burning the vast resource of used tyres which will only contribute to air pollution.

“The effective use of used tyres for soil erosion control is thus a largely unexplored option that has tremendous potential in the rehabilitation of degraded landscapes,” concludes Ken.

FIGURE 3: Details for the construction of the scrap-tyre retaining structure. The original vertical slope is altered to less than 45 degrees. The first layer of tyres is buried in the streambed and all the tyres are filled with soil and gravel and then planted with a variety of robust local wetland plants.

For more information contact Ken Coetzee on (+27)76-227-5056 or send an e-mail to consken@mweb.co.za.

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