It was an eye opener for me because I had never really thought about it before – the critical importance of water.
In Ireland, we take it for granted - and sometimes curse it - but water is absolutely basic to life and that was very obvious as I toured through the state of Western Australia (WA) in Australia with ITLUS in early 2020.
Vast expanse of countryside
Rainfall and water are precious in WA – a vast countryside of open expanse, with the emptiness punctuated by occasional forests and flood warnings on roads for when the rain does come.
Perhaps the strangest thing is that sinking a well for water is not an option, anywhere. While there is ground water in the ground, it is all high in salt and so not usable.
Not being able to take water from the ground means that rain is the only source for man, plant and beast. So, every effort is made to harness as much of the rainfall as possible.
Household and farm water supply is harnessed initially from the land through captured overland flow. Most countryside is quite undulating, with hills and hollows that channel water flow even on apparently flat land.
When rain falls, much of it would appear to run across the surface rather than percolate deep into the soil.
One farmer suggested that it takes 50mm to 60mm of rain to wet the soil to the point that water begins to flow across the surface.
The countryside was dotted with dams, which are holes or sumps created to catch the flowing water.
The soil itself is also very fragile and very low in organic matter because of low vegetation production and the searing heat. This means it is prone to erosion by wind and water and the ponds act as sediment collection also.
The dams were carved out of the ground and strategically located
The dams were carved out of the ground and strategically located, generally close to the road and near the end of a particular overland flow path.
So, when rain fell and water flowed across the surface of the land it made its way, or was altered to push the flow path in a specific direction, to maximise water gathering or harvesting in these collecting areas.
These sources of water are equally essential for humans, animals and other farming activities.
Water for household use was generally taken (pumped) from these holes into plastic storage tanks located close to dwellings or farmyards.
Here, any further sediment carried in the water could settle out to leave the water as clean as possible for use.
Remnants of old windmills could frequently be seen around the countryside, which had been used to pump water either directly from the ground in the past or from the water holes to other areas or to header tanks on higher ground.
When we think of a hole in the ground, we think of an excavator digging out the earth. But this was not the case in WA.
Many of the farmers we visited were availing of the opportunity to clean out their dams when they were virtually dry following three years of drought.
This was important to maximise water holding capacity when rain did come. However, even this cleaning of the dams did not involve excavators.
Dam cleaning was a two-man, two-tractor operation. A cleaning bucket was used, which was a device somewhat similar to the bucket on an old drag-line, but it worked in both directions.
This was pulled over and back and over and back by a tractor on each side of the dam. The bucket gathered the sediment, a bit at a time, as it was pulled to and fro.
The bucket is pulled up on top of the sloped bank and when the pull comes from the opposite direction, the contents get unloaded on the top as it is pulled back down to work in the opposite direction.
The bucket did not break through the bottom or sides of the dam, but the sliding motion probably helped to seal all the surfaces to prevent water leakage.
The subsoil seemed to be high in silt and clay, which was important for the system to work.
We saw many of these operations in progress during our travels. It seemed like a straightforward job, but it probably involved a level of precision that was not obvious to me.