Do floods really need to be devastating every time we get that much rain?
By Chris Henggeler, Kachana Station, January 2011
No they do not. There are two good reasons.
We can become better at anticipating floods, preparing for them and mitigating their impact.
We can significantly increase the amount of water trapped and stored in our rangelands and in upper-river rainfall-catchment areas.
The above is a short summary of what this paper is about. What follows is an attempt to make palatable for the conscientious citizen the complexity that we are dealing with. Complex because we are dealing with the dynamics of nature which includes physics, chemistry, biology as well as human agendas.
Complex too because in modern times the individuals best qualified and positioned to manage broader landscape-settings have become a politically insignificant minority of the electorate that do not command the attention of the general city-dwelling majority.
Complex furthermore because we are confronted with some new environmental thinking that flies in the face of many theories still being taught in schools, colleges and universities. Obsolete thinking that to some extent also underpins some of our nation’s legislation and policy.
N.B.: Some voices link severe flooding to changing weather patterns.
The issue of increasing unpredictability of weather is the subject of an earlier text: http://www.kachana.com//environmental_management/gi_is%20global%20warming%20the%20real%20issue2007.php
The paper below focuses on what we can do about a known predicament.
- We can become better at anticipating floods, preparing for them and mitigating their impact.
Reason number one may seem obvious to many. After the Queensland 2011 ‘inland tsunami’, here is some of what people will surely focus on:
- How can we better model possible flood scenarios?
- Do we need to revise building codes and building permit-systems?
- Do we need to revise and amend town-plans?
- How can we improve response capability?
- How do we educate people on safe conduct during such times?
- Do we build more dams, levee banks and drainage channels?
- We can significantly increase the amount of water trapped and stored in our rangelands and in upper-river rainfall-catchment areas.
A moving mass of water about “90 kilometers long and 40 kilometers wide”…
Q.: If the average depth had been one meter, how much water is that?
A.: 3’600’000 mega-liters; about a third of what Lake Argyle holds when she is full…
A lot of water, but there is another way of looking at that volume:
When 36 average Kimberley cattle stations get 25mm of rain each that they can hold onto in their soil, it is this amount of water that can be stored. Healthy living soils however are able to store a lot more.
Now we know that if enough rain comes down fast enough and long enough, the country is not going to soak it all up and it will head down-stream. We cannot do much about that except for trying not to get in nature’s way.
We also know that in many, many instances that country sheds water because it has lost the capability to absorb it. If we are to minimize downstream flooding in the future our only option is to reverse this situation. (Photos courtesy of the ABC)
Point two (above) calls for a complimentary approach to the first one. An approach that is proactive, one that is flexible and holistic. We look upstream, we look at the soil beneath our feet and we look at geography. We begin to align our human agendas with how nature functions.
(Photo: Kachana Pastoral Company)
(CAVEAT: I know that much of what I say will apply to other areas of Australia, Africa, India and many more places, but it is dangerous to generalize, so please be careful how you quote me, and accept that I write this paper with primarily Australia’s Kimberley in mind. Specific comment relating to areas beyond the Kimberley would be inappropriate without local analysis of eco-system function.)
Since biblical times (Noah's Flood) the word ‘flood’, if not by definition then at least by tradition, has an ominous ring to it.
Officers charged with the safety of people recommend staying clear of flooding and issue advice on how to prepare and how to respond. Our media often alerts us to damage and hardship associated with flooding. Emergency services train people to perform rescue operations under dangerous circumstances…
On the other side of the coin: Ancient Egypt was a civilisation built and sustained by capitalising on the opportunity that floods represent. Flood-irrigation in agriculture even today mimics a portion of that process.
Floods in some cases may be regular cyclical events.
Nature also uses floods as infrequent non-cyclical disturbances to maintain or rebuild diversity and complexity within eco-systems.
When viewed within a geological time-frame we notice that nature has only very recently released a new element to flooding: Humans
Humans have a significant influence in shaping landscapes and on the flow of water. We only need to fly over a city or what is now a densely populated area and then take a look at some historic photographs of the area to appreciate what massive change can occur on a landscape in less than a hundred years.
Let us differentiate between ‘original natural floods’ and ‘human-enhanced natural floods’. We use the word ‘natural’ in both contexts because nature put us humans out there in the landscape and whatever we do is not exempt from nature’s laws.
(Photo: Kachana Pastoral Company) (Photo: Courtesy of ABC)
Original natural floods:
(As mentioned above we have two broad distinctions.)
- regular cyclical events
- macro-cycles and infrequent non-cyclical events
How these events manifest themselves depends on multiple factors:
Time of year/season
Amount of rain
Intensity of rain
Duration of rain
Frequency of rain
Soil-health at the surface
Structure of deeper soil, geology (nature of aquifers etc.)
These factors immediately come to mind. There are others like tidal influences and position of the moon and more…
It rains, the land gets wet; if rain continues at some stage we reach a point of saturation and raindrops no longer go down; they stop, they accumulate, they take a course dictated by gravity and eventually head ‘down-stream’.
(Some scientists make use of the term ‘Field capacity’. This refers to the amount of water held in a soil after gravitational water has drained away. Source of definition: http://stats.oecd.org/glossary/detail.asp?ID=948; Source Publication: Glossary of Environment Statistics, Studies in Methods, Series F, No. 67, United Nations, New York, 1997. - To avoid confusion this term will not be used in this paper.)
At the latest, when a landscape can no longer absorb more water, all rain that then falls will begin to pool. If rain continues, the area begins to flood, and gravity and the path of least resistance take over. (Photos: Kachana Pastoral Company)
Human-enhanced natural floods
In Australia (and therefore also in the Kimberley) we arguably have three broad types of human-enhanced flooding (or flood components) to deal with.
- Pre-Captain Cook human influences on eco-system function
- Post-Captain Cook human influences on eco-system function and current up-stream management.
- Modern bureaucratically ordained flooding.
In each particular flood-situation analysis of the scenario would produce some sort of unique formula made up of elements and influences listed above. Computer-modelling allows for many of these. It helps us better understand what may happen. However in this paper I wish to focus on how to significantly reduce and subsequently reverse historic and modern human factors that currently promote increased flooding.
Human contributions to flooding
Before we explore solutions let us first examine human contributions:
- Pre-Captain Cook human influences on eco-system function do not apply in every case, but they certainly do to the Kimberley and to much of inland-Australia.
According to scientists like Tim Flannery and Jarrod Diamond the Australia first seen and visited by Captain Cook was vastly different to the Australia that humans first set foot upon many thousands of years earlier.
Over the course of thousands of years, humans helped shape Australia’s eco-systems and contributed significantly to the way in which they functioned.
We only need to walk over a lawn or patch of grass on the exactly same path every day for an extended period of days to appreciate that changes can be brought about rapidly and very easily. Human behaviour that included hunting, gathering and the lighting of fires was new to the original Australian landscape. Now let us appreciate that unsuspecting humans would have been easy prey for the reptilian monsters that roamed the landscape or lurked hidden in the scrub near water. There was the up to 7 meters long Megalania, a Gigantic goanna who weighed in somewhere between 200kg and 1000kg or more. Then there was Quinkana, a land crocodile up to 3 meters long and weighing over 200kg. Not to forget Wonambi the 100 kg python (reaching 6 meters long with a 30cm diameter) and several species of now extinct crocodiles. We can hardly blame the first human visitors to Australia for having used fire to protect their camp-sites and as a weapon against such formidable foes. Human lit fire in Australia would primarily have been a life-insurance policy for the first new Australians; a life-insurance policy with an annual ecological premium.
The exact sequence and nature in which the landscape changed remains a subject of scientific debate and speculation. What we need to know is: massive changes did take place. Animal species became extinct. Vegetation patterns changed. Carbon that would otherwise have been incorporated into the soil through biological processes ended up being exhausted into the atmosphere by human-lit fires throughout the year. With a (gradual or rapid) decrease in groundcover we find an according increase in flooding when there is heavy rain. - People who go camping in the bush away from designated camping areas, if they are not careful soon realize that the longer they stay in one spot the further they need to go in search for fire-wood. If they camp in the rain they will notice that the first puddles often form on compacted ground where people spent a lot of time standing around the fire…
Wet kitchen in the stock-camp (Photo: Kachana Pastoral Company)
The point here is that how humans behave and how they in turn influence the behaviour of other animals will impact vegetation and the health of soils. Flood patterns change accordingly. For the same amount of rain, many parts of Australia pre European settlement would already have been experiencing a far greater degree of flooding than original Australia prior to arrival of the first humans. This notion is supported by Tim Flannery’s observation that Lake Eyre was a fresh-water lake when humans first arrived. This impacted local climate.
- Post-Captain Cook human influences on eco-system function and current up-stream management.
Not only did European settlement (as the word implies) bring new human behaviour patterns to Australia, it also changed existing patterns of nomadic human behaviour. Patterns that had blended in with the way Australian landscapes had been shaped and maintained by humans over thousands of years.
Tracks, roads and buildings shed water. New permanent infrastructure = new permanent change and continued influences on what nature does.
Clearing land and cultivating monocultures will have a different effect on soils than sporadic patch burning.
Land abandoned by its earlier inhabitants and ignored by industry no longer has a mosaic of vegetation; wildfires now expose hundreds of square kilometres of ground at a time. Habitat, shelter and biodiversity are lost. Soils lose their ability to capture and retain water.
(Photos: Kachana Pastoral Company)
The introduction of large herbivores and new fire regimes with a focus on grazing and protecting communities from wild-fire will have an impact on vegetation.
Modern soil science indicates quite clearly that it is the role of healthy actively growing plants to channel energy to soil micro-organisms. A depletion of vegetation (be it due to intended land-clearing, the frequent use of fire, poor pastoral practices or simply a lack of herbivores to keep vegetation healthy) translates directly to: less energy, water and air for the billions and billions of little beasties that need to live in the soil to keep it healthy. (Healthy living soil has spongelike properties; it absorbs water rapidly and releases it gradually.) When soil-health declines the capacity to absorb and retain water changes. Soils dry out faster and soil-erosion increases. As soil is lost from an area so the water-storage capacity for that area is lost. Some soils seal up and shed water quickly and long before they absorb the quantities of water that they should. Some soils get compacted and their capacity to hold water is reduced to the top layers; they are no longer able to service underground aquifers. Some soils get covered by algal capping and less water and air reach the soil; there are a surprising number of modern land management practices that will contribute to flooding e.g. the building of dams and thus raising water-tables may also reduce the amount of rainwater an area can absorb and retain.
Many modern practices may be desirable for much of the time and can thus be justified; we simply need to accept that as we go about our daily business we humans constantly exert an influence on how a landscape can deal with what drops out of the sky and that this may have down-stream implications. Accordingly communities cannot isolate themselves from what takes place up-stream.
Wetland systems do not usually disappear within one season. It may take decades for all traces of a wetland to disappear... Stark seasonal contrasts often hide such processes from the casual observer. If such destruction takes place in isolated upper-catchment country what does it take for a down-stream community to become aware?
(Photos: Kachana Pastoral Company)
This takes us to what I consider to be the most critical element we face today:
- Two-fold modern bureaucratically ordained flooding:
A. Inappropriate legislation based on faulty assumptions and according practices being promoted by Ag and Conservation Departments and other Government authorities that regulate or affect the management of vast tracts of private and public land.
B. Public and private infrastructure positioned on flood-plains, clay pans and former swamps and in places where human rulings and agendas are at odds with the laws that govern nature.
Before taking a closer look at these, we must accept that ‘bureaucracy’ is a system chosen by government and accepted by us (the people). Therefore individuals hired to work within that system must not be blamed for the shortfalls of the system.
It is counter-productive to point fingers at individuals. This of course leaves unique communities and us as individual citizens in a bit of a fix...
Where does the responsibility lie? Who is accountable? The department is not to blame... and the people in it cannot be made accountable... a fact we need to understand.
However, such is the nature of the system we have chosen to live with.
- Inappropriate legislation based on faulty assumptions and according practices being promoted by Ag and Conservation Departments and other Government authorities that regulate or affect the management of vast tracts of private and public land.
World-wide there is over 50 years’ worth of private research that clearly shows that traditional European-type land-use techniques are largely inappropriate in seasonally dry climatic conditions (as prevail in much of Australia). Mistakes made in Africa, India, and in the Americas have also occurred in many parts of rangeland Australia. In most cases the consequences of such mistakes continue to haunt us today. Some common results are desertifying landscapes, dysfunctional rural communities and an increase of poverty in big cities to which people migrate in the hope of a better life. A change in run-off coefficients is another common result, as is increasing severity of droughts and floods. (We use the ‘run-off coefficient’ to calculate how much run-off to expect from a particular area for a given amount of rain.)
Why is new environmental-management knowledge so slow in being adopted?
The road that leads to the failures described above is not always that obvious. Due to the seasonality of nature, our dynamic modern lifestyles and a century of unsurpassed innovation, underlying trends are often well out of view until they result in a crisis; often even then our tendency as humans is to focus on the crisis and not on understanding what caused it.
Despite our many technical achievements our species remains bound by the law of the harvest. Any practice that is not in line with how nature functions will eventually fail. If a generation or more of well meaning people have enjoyed socially acceptable life-styles in the process, this makes failure all the harder to accept. We cling to a track-record and believe the ‘crisis’ to be something out of the ordinary.
Factors listed above are compounded by the nature of our chosen political model: there is more political mileage in demonstrating action when crisis hits, than in expending public funds to minimise the impacts of a future crisis that is of ‘low probability’; more so if such a crisis may be seen to only affect a minority.
Add to this the nature of bureaucracy where an individual is penalised for wrong decisions, but not rewarded for innovation. (Bureaucracy is designed to coordinate the flow of information – Bureaucracy is not designed to lead, to be innovative or to conceive new policy, or to wield responsibility. - Yet politicians and people new to an area go to these very departments to seek guidance!)
Once faulty legislation is in place, bureaucrats have no option but to run with it and do the best that they can. The hitch is that we can lock up people for not abiding by our rules, but we cannot lock up a drought, flood or fire.
I have experienced instances where more energy goes into covering up for faulty legislation and practices than it would take to address the issues at stake in a practical and effective manner.
Change may prove to be expensive, but are we not already paying even more dearly for our delay to respond to nature’s messages?
If our thinking is faulty, Nature tends to over-rule our planning and well intended legislation
(Photos: Kachana Pastoral Company)
- Public and private infrastructure positioned on flood-plains, clay pans and former swamps and in places where human rulings and agendas are at odds with the laws of nature.
More than that, we allow vast areas of fertile productive land that used to have an immense capacity to capture and store water to be “developed”.
It does not seem like such a very long time ago that many small communities were isolated by distance and by lack of communication-systems. Some were also cut off regularly due to seasonal conditions. Such communities needed to be self-reliant or else they would not survive. Local knowledge came from what was tested and from what worked. It was accordingly respected and passed on and acted upon. Today this is the subject of history books. State regulation and Local Government Acts have streamlined the laws and guidelines under which today’s communities must exist and are to develop. An army of young university-trained minds brings fresh and new thinking to the remotest of communities and assists the locals in interpreting the regulations imposed from on high. But what if we have something that is unworkable in a particular community or incompatible with the geography of a particular area?
As I understand it there is no formal structure in place that would allow for old or new practical local knowledge to override the bureau-political path that we find ourselves on.
For a fast growing community like that of the Ord River Irrigation Area there is a new bureaucratic element. Due to politically sanctioned search for eternal economic growth big-business is elbowing its way into the region. Big business brings with it confidence, jobs, turnover and a promise of stability; this can be a benefit to an area. However the hidden danger it brings with it too, is that it can sway department-policy, set precedents and can more often than not seemingly afford to ignore local knowledge. Big business also attracts more regulation. New layers of bureaucracy are forced onto existing local businesses.
But what does all this have to do with floods?
Nothing directly, but a great deal indirectly:
The original community model was by necessity geared around how nature functioned in its particular area. The rate of progress was adapted to local experience which was both available as well as accessible. People had some idea of what was taking place upstream and needed to accommodate for it on an almost seasonal basis. Today we have a situation where in many instances the community has no idea what is happening up-stream. Regulations give developers a sense of security and their energy goes into ticking all the right boxes without a consideration as to whether their development agenda is compatible with that of Mother Nature. The sad fact is that tragedy and damage have already been unwittingly programmed into a lot of settings. Nature follows her course and it is merely a question of when and how we pay the price.
A swampland is developing along a stretch of As the channel widens up-stream, can increased
highway due to redirected spillage “up-stream”. flow be accommodated down-stream?
(Photos: Kachana Pastoral Company)
In a few years time we might be in a position to say that the flooding in eastern and south-eastern Australia early 2001 was a non-cyclical event that nature threw in our path.
How soon will something like this happen again?
Do we prepare for such an event?
Then again if (as some predict), weather patterns are in fact changing, then can we really afford not to take a closer look upstream?
Are catchments being managed to store or to shed rainfall? (Photos: KPC)
Questions that beg the asking
- Have poor or ill-informed management practices in recent times negatively impacted the capacity of a landscape to absorb and retain water?
- If so, how and to what extent? (How is the situation being monitored?)
- Do we have a situation where certain landscapes now capture and retain less water than in earlier times?
- We know that through compaction and surface-capping run-off increases and takes place sooner than before. Infiltration rates have been reduced, but does this also affect the quantity of water that could be stored?
- Have we reduced the recharge capability of some of Australia's minor and major aquifers?
- Do increased run-off coefficients, translate to increased run-off prior to saturation of the soils?
Fire exposes soil-surface. Exposed surfaces facilitate run-off. (Photos: KPC)
Obviously topography, land-type and height above impervious bed-rock play significant roles; not only ground-cover and soil-health.
From my travels through seasonally dry regions of the world and after over 20 years of in-depth study of the landscapes in the Kimberley (North Western Australia) I suspect that bureaucratically enhanced man-made flooding is a major contributor to the extent of loss, damage and hardship experienced as a result of most floods in this day and age.
It is always easy to criticize, and hind-sight is a wonderful tool. However rather than using my position (perched in the upper-catchment of five large river-systems) to apportion accusation and blame, I suggest new and alternative ways of addressing the issue of flooding in at least the Kimberley region.
I know that most of the Kimberley-communities are not well prepared for unusually high rainfall events. I believe we had an indication of what could happen in March 2000, but few of the lessons seem to have sunk in.
The Dunham River gave us a clear message in March 2000 (Photos: L. Heading)
The good news is that we have one well established industry here in Australia that could be instrumental in revolutionizing the approach to water-security on this whole continent whilst simultaneously reversing historic human contributions to flooding.
In coming years we will see that in Australia, as in other arid parts of the world, Pastoralism in its broadest sense – that is beyond the export of food and fibre – will become one of the major players in dealing with many of the modern ecological challenges that we as humans face in today’s world. Will such an evolution of land-management practices in the Kimberley and other sparsely populated regions come about in a proactive effort to focus on healthier and productive landscapes? Or will this development come about in a fitful, haphazard and uncoordinated manner as people increasingly notice that they are running out of options?
In a second paper I have outlined how a focus on healthy eco-system could take us onto proactive path with many political win win options.
Ancient, past and present human contributions to flooding can be reversed or compensated for. Healthy water-cycles resulting from a focus on broader landscape-health and productivity are the most cost-effective means of mitigating the effects of flooding. It will either take political will and leadership or more harsh lessons dealt out by Mother Nature, to bring about the necessary change of mindset for communities to endorse and to reward the practices that are called for if we wish for this to happen.
Personal observation and research. Research sections of: www.kachana.com
The Savory Institute. World leaders in practical responses to desertification and associated challenges: http://www.savoryinstitute.com
Dr Elaine Ingham’s work on the Soil Foodweb: www.soilfoodweb.com
Flash water cycle demo (850 K) demonstrates the commonest causes of flooding, drought, and desertification.
How do we prepare our landscapes for rain? A visual appreciation of the challenge: http://www.kachana.com//environmental_management/pp_prepare_for_rain.php
Animal Impact: a "Power Tool". A fact-sheet describing the most important tool at our disposal to stabilise the world’s climate and to secure sustainable supplies of water and healthy nutrition: http://www.kachana.com//environmental_management/pp_animal_impact_power_tool.php
The Dunham River in “The year of the Out-Back”. A practical assessment of what is taking place upstream of Kununurra: http://www.kachana.com/environmental_management/gi_dunham_river_2002.php
Input to Kimberley Waterways paper. A grass-roots response to a departmental questionnaire:
International recognition of work conducted by Kachana Pastoral Company: http://www.managingwholes.com/kachana.htm
Case studies of landscape restoration using low-tech high-skill techniques mentioned above. http://www.managingwholes.com/--environmental-restoration.htm
The Savory Institute. World leaders in practical responses to desertification and associated challenges: