This Sustainable House

Posts Tagged ‘swale’

Or perhaps, mote accurately, collect water while the rain falls…

Water is the number one limiting factor at TSH, as it is for most Australian farmers. We are, after all, the driest inhabited continent on Earth.

Like most rural properties, TSH has no reticulated water access but relies on the water that can be collected off the roof or catchment run-off. In the case of roof run-off the water is stored in a series of thanks with approx 140,000L capacity. However catchment run-off is a different tale with main storage being one medium sized delapidated dam. Damn!

The fact that our dam doesn’t hold water, if you’ll excuse the obvious pun, is actually a blessing as it encourages me to be more creative with how water is stored on the property. Which brings me to the point of this post… Swales!

Swales are an earthwork designed to capture water in-situ and transmit that into the sub-soil. Whilst in a dam one attempts to capture water with an impervious layer, in the case of a swale we capture it with a permeable layer. The basic principle, as demonstrated below, is to trap rainwater using trenches/embankments placed along a contour and then allow this water to permeate into the soil where it flows under the surface. This has the advantage of lowering evaporative losses as well as placing the water right where our plants need it, at their roots. It also reduces erosion and, best of all, requires NO energy to run a pump… Grand.

In the case of TSH there are a couple of areas that would benefit from swaling. The first area is in the quarantine yards where the swales will capture road run off and direct it to a better use. The second area is the rear paddocks where the run-off can be chanelled along the countours to collect both from the ‘interswale’ areas and the neighbours paddock.

As we develop these earthworks I will post additional comments but in the meantime just imagine the possibilities.