Toby Nichols, Edah Station, Yalgoo Western Australia.  Email: jerome1pastoral@gmail.com

 

On Edah Station, in the Western Australian southern rangelands, we are using a range of methods to rehabilitate existing eroded areas and prevent further damage that may occur during times of high water flow.

Adapting techniques described by Ken Tinley and Hugh Pringle in their Rangeland Rehydration Field Guide and Manual, as well as borrowing ideas from David Pollock of Wooleen station, and Peter Andrews of Natural Sequence Farming fame, our rehabilitation work focusses on slowing streamflow and increasing water infiltration.  This not only improves the water cycle directly but also fosters sediment deposition which may allow gullied stream beds to fill up.

On Edah,  we have carried out considerable work on the eroded house creek.  The following photo series (Photo 1 A-D) shows how ‘scrub sieves’ (also known as ‘leaky weirs’) have been used to curb water flow in the creek. Recycled steel pickets are used as the base for the weirs – they are spaced at about 1 metre with 3 strands of (recycled) plain wire.  Sometimes the pickets can be knocked in, but more often we have to use a rock drill and concrete them.  We then lay cut scrub across the stream bed on the upstream side of the barrier.  My understanding is that such structures slow and hold up stream flow without stopping it – in other words the barriers are permeable or leaky to a greater or lesser degree.

 

Photo 1.  Series of photos of the house creek commencing where visible stream flow ceased and then working upstream – A. End of visible water flow; B. 100m further upstream; C. 300m further upstream showing a ‘scrub sieve’ in action; D. 500m further upstream showing an additional ‘scrub sieve’. [Individual photos can be viewed in greater detail by clicking on each link]

 

We have also used a version of ‘scrub packing’ on some of the tributaries of the house creek..  Here cut scrub is packed into the gully to slow water flow (Photo 2, looking downstream).

 

Photo 2.  ‘Scrub packing’ on a small tributary slowing water flow.

 

In many  areas of our property we have used ‘whoa-boys’ – these are simply earth banks built across tracks to holdup and disperse stormwater running down the track (Photo 3).   We are also incorporating them into new fencelines in an attempt to address/prevent gully erosion due to water flow.

 

Photo 3.  A ‘whoa-boy’ holding up storm water which would otherwise have flowed down the track and into the house creek shown in photos 1 and 2 .

 

In the long term, these methods will only be successful if we can control total grazing pressure in the catchments of the watercourses, so that rainwater will infiltrate the soil rather than running off into fast flowing creeks and rivers.

We welcome any suggestions, questions or comments on the techniques we have used.  Please don’t hesitate to contact me at jerome1pastoral@gmail.com.  All of the photographs in this report were taken within 48 hours of a recent rainfall of 12 mm.