We live in an age of uncertainty. No one knows for sure what will happen with global warming. Some people think it is just a myth to help sell newspapers, but the odds are that it is for real so it is prudent to take protective action. In the short term we can do nothing to reverse the basic causes of global warming so we had better learn how to live with it. The greatest danger for most people is water scarcity with more of what we are experiencing now; longer periods of drought broken by random severe rain storms.
Governments may like to tell us that they are in control and certainly they have some grand plans but the community has to accept that the days of the Government providing abundant water are over.
Governments are failing to address the key threat – the increased threshold for run off. The increased energy in our weather systems means higher temperatures and stronger winds which inevitably means higher evaporation and hence drier soils. Rains which would once give run off into our dams will be simply absorbed by the soils without run off. At one time when the soils were moist a 20 mm rainfall may have given run off, now it is typically 50 mm before there is run off and in the future we may be looking at a 100 mm threshold.
Governments, with their classic approach to water management can do little to protect society from this rising threshold but communities and individuals can. They can take action themselves to manage this risk of water shortages and have a perfectly viable life style taking advantage of simple but effective technologies to manage water at the local level.
As climate change progresses the already dry arid regions, most of Australia but particularly SE Queensland, are likely to receive a triple whammy
*drier soils in the catchments areas giving less runoff
*less rainfall and
*an increasing population.
Is this necessarily a formula for disaster? No. Currently we only catch a minute proportion of the rain that falls, our dedicated catchments are only a very small proportion of the total land area and the bulk of the rainfall falls as smaller rains which simply wet the dry soil without runoff.
The solution lies in harvesting the smaller but more reliable coastal rains over a much larger area wherever they may fall. The simple but effective technologies of water harvesting resolve the problem of catching water over the entire area, not just catchments, making use of both large and small rains.
But there is a snag. Water farming catches and uses water in local areas: they are intrinsically small scale local schemes which are not in the vision of the current water bureaucracy which is focused on mega engineering schemes. Just spending money does not solve the problem – there must be more intelligent thought.
If we are to survive the effects of global warming we must undergo a fundamental shift in attitudes in how we manage our water - learning to harvest and use water locally.
But the change is not just technology, indeed many of the technologies have been in use for hundreds of years. The real revolution is the change to communities taking action to collect and manage their water locally. It is a social revolution in our management of water.
The role of traditional dams needs to change. Currently many of our dams are approaching empty. At some point in time, no one knows when, there will be a major rain and the dams will fill. Local captured should be used whenever local water is available substituting for water which we currently take from dams. The water from these freak rains captured in our dams should be regarded as emergency water for the next long period until the next freak rain.