Early explorers, John Oxley and later Charles Sturt, described what is now known as the Murrumbidgee Irrigation Area as a desolate, uninhabitable landscape. That was before irrigation. Today the region produces wine grapes, citrus, apples and stone fruits, vegetables, wheat, barley, oilseeds and, of course, rice.

Proud locals boast that despite the drought, and because of irrigation and the vertical integration of the food industry, 160 semitrailer loads of quality, fresh food ready for the supermarkets of Australia leave the towns of Leeton and Griffith each day, and a further two and a half trains of containerised food for markets around the world. Not all is produced on irrigation farms, but the certainty irrigation provides has facilitated the development of the food industry with value adding occurring locally to an industry now worth between$2.5 and $3 billion annually.

Leeton is known as the headquarters for the Australian rice industry, and is the location of one of Australia’s most successful, vertically integrated agribusinesses – SunRice.

In years of adequate water about 150,000 hectares of rice are planted across the Murray Darling Basin providing habitat for an estimated 5 billion frogs. The spotted grass frog, barking marsh frog, plains froglet and Peron’s tree frog are four of the most common species which live in remnant patches of bushland and breed in flooded rice bays and irrigation channels between August and May. Scientists at the Institute of Applied Ecology at the University of Canberra estimate that every hectare of Australian-grown rice produces 33,000 frogs in addition to the almost ten tonnes of rice.

Of course birds eat frogs, and so perhaps not surprisingly the Murrumbidgee Irrigation Area has also become home to thousands of water birds including rare migratory species.

Incredibly the Guide to the Proposed Basin Plan released last Friday does not mention the word “frog”, or “Amphibian” – not once.

The Guide recognises that most of the 30,000 wetlands scattered across the Murray Darling Basin are on private land and states there are 2,442 key environmental assets across this predominately agricultural region.

In fact during the last 90 years through a constant improvement in management, irrigation techniques, fertility and productive capacity the “desolate” plains are now teeming with wildlife. Of course not all frog species have thrived all the time with the endangered Southern Bell frog undergoing recent decline from the introduction of exotic fish and the degradation of some wetlands particularly from overgrazing.

It was progressive politicians who witnessed the devastation and totally dry rivers that accompanied the droughts of the 1860’s and the late 1890’s that drove the early development of irrigation in the Basin: they wanted to conserve water at times of excess, to sustain farming communities even in drought years. Few realise that since European settlement the Murrumbidgee has run bone dry four times: during the droughts of the 1840s, 1860s, 1890s and 1913-1915. It was so dry in the early 1860s that horse races were held in the bed of the Murrumbidgee River downstream of Gundagai.

Water infrastructure is now extensive across the Basin, so, even during the recent prolonged drought, there was enough water in the Hume and Dartmouth dams to provide for the world’s largest ever environmental water release in October 2005 with 513 gigalitres of water (the equivalent of a Sydney Harbour of water) released into the Barmah-Millewa red gum forest which straddles the Murray River upstream of Echuca.

Without the dams, given the severity of the drought, the Murray River would have likely run dry over the last decade – never mind having enough water to flood a very large forest.

When the then Howard government introduced emergency measures in 2006, making water for Adelaide and other cities and towns within the basin a priority, flows from the upstream dams to the Lower Lakes in South Australia were significantly reduced for the first time in decades.

Malcolm Turnbull, then Water Minister, believed the system was in crisis and the Howard government responded to cries, in particular from its South Australian Cabinet Ministers, by drafting a new Water Act.

Back then the leader of the Australian Greens, Bob Brown, was explaining that it has been “scientifically proven” that 1,500 gigalitres of environmental water is needed to keep the Basin healthy and in particular to keep the Murray’s mouth open. Until very recently, this same figure of 1,500 gigalitres was being quoted by Mike Young, University of Adelaide, and other water experts as the best science.

The Guide, released by the Murray Darling Basin Authority last Friday, now claims that the best science establishes that at least double this amount, 3,000 gigalitres, is the absolute minimum, and 7,600 gigalitres is a more realistic target. The major change has not been in the science, but rather expectations have grown within the ranks of Green activists, along with disdain for Australian agriculture, with rice growers in particular increasingly held in contempt.

The new Guide has been touted as an independent comprehensive scientific assessment of the environmental needs of the Murray Darling Basin, yet incredibly there is no justification provided in the 223-page document for the extraordinary revision of what was “scientifically proven” just a few years ago that is the need for up to 7,600 gigalitres when previously 1,500 was considered more than adequate. Incredibly the new Guide even lacks a reference list, normally a minimum requirement for a work of science.

The new water sharing plan, if implemented according to the Guide, will ensure more water is channeled directly to South Australia but no consideration is given to how this will impact on upstream floodplains.

Indeed at the moment, when it rains there is enough water for everyone, but if the proposals in the Guide are implemented, a near permanent drought will become a feature of the Murrumbidgee Irrigation Area and this will significantly impact on the frogs.

It would be prudent for any radical new plan – the new Guide claims to provide a blueprint for the complete overhaul of water management in the Basin – to carefully consider all the implications of phasing out industries that provide important habitat for key indicator species. Yet incredibly the new Guide does not even consider one species of frog. Indeed there is absolutely no consideration of how changes in water allocations, in particular channeling more water directly to South Australia, will impact on the dozen or so species that comprise the 50 billion frogs many of which are reliant on irrigation along the Murrumbidgee.

 This article was written by Jennifer Marohasy and Ron Pike.  Ron Pike, now retired, is a third generation irrigation farmer from the Murrumbidgee Valley.  It was first published at On Line Opinion .

“The lack of flow volumes in the rivers of the Murray Darling Basin (MDBC) in recent years is not due to irrigation and over extraction.  The facts are that without the storages and the irrigation industries, conditions would have been considerably worse.   Throughout the MDB there is presently more wetland habitat than there would have been had there been no irrigation for the last several years.  It is also wrong to suggest that increasing stream flows by releasing extra water from storages, somehow benefits the environment.   It makes no appreciable difference to the  environment whether the Murrumbidgee at say Narrandera is running at 3,500 megalitres per day or 25,000 megalitres per day. The flows in both cases remain within the banks and do not, and cannot, water the floodplain or most wetlands.

Reading the journal notes of the men who were the first explorers of the rivers of the Murray Darling Basin (MDBC) gives us a number of facts which are still relevant if we care to understand the system and wish to maintain it for the good of future generations.

The explorers note that once the rivers of the MDB leave the hills and commence their meandering journey across the plains, the stream flow is twenty to forty feet below the surrounding flood plain.  Only at the Macquarie Marshes, the wetlands of the lower Lachlan and to a lesser extent above the Bahmar Choke in the Murray do the rivers flow above their bank, other than in large floods. 

Most of the other rivers in the MDB, including the Murray have the same characteristics; once they reach the flood plain (it is on the flood plain that the wonderful River Red Gums grow and also the vast but irregularly watered wetlands preside); they flow well below the surrounding plains.   Therefore these wetlands are only ever flooded in periods of excessive catchment rainfall which causes the river to flow above its banks.   When this happens the wetlands explode in a volcano of abundant life across all species natural to this environment. 

A magnificent, spontaneous and symbiotic food chain develops only limited by the environment in which it exists, and sadly it seems, not understood by many present day commentators.

In order to understand the system it is necessary to have some understanding of water volumes. 

A megalitre is 1 million litres or 1000 cubic meters. It is the measure that is used for all sales and purchases of water throughout the MDB. It is also used by all Municipal authorities.  For those who want a comparative picture, an Olympic Pool is around 1.7 megalitres, depending on depth and width.

In the case of the Murrumbidgee, the photograph shows the river running at around 2,400 megalitres per day. If a release from both Burrinjuck Dam (full capacity 1.03 M megalitres) and Blowering Dam (full capacity 1.6 M megalitres) of 20,000 megalitres per day were to be made in this situation, it will not put water onto the flood plain. A flow of 40,000 M/d will put some water into a few low lying Billabongs and backwaters, but will not put water on the floodplain.  All that would be achieved is a high river flow for a few days. Most of which would run to the sea and to waste.  The same applies to most other valleys in the MDB.

To put water onto the Murrumbidgee floodplain and fill the wetlands requires volumes in excess of 150,000 megalitres per day. This is far beyond what is possible from existing storages.  It will only ever be achieved by Mother Nature and man has no influence on its recurrence and little on its magnitude.  As an example of what is required to flood any of the MDB river valleys, the Murrumbidgee flood of September 1974 is enlightening.    Following heavy rain in the area of the ACT, Burrinjuck dam quickly filled and a day later there was almost 400,000 megalitres per day going over the spillway, plus the outlets were fully open. There was sufficient water going down the Murrumbidgee Valley to fill Burrinjuck from empty every two days.

While this flood reached a height of 9.19 meters at Wagga Wagga it was not an exceptionally large flood historically.  This and greater volumes are required in most of the river valleys of the MDB to water the wetlands.

Our early explorers and settlers recognized the huge flow changes that occur in our river systems. They were also aware that this old river system was very unpredictable. It moved from abundance of flow to completely dry at irregular intervals. 

While a vocal minority of modern man seems unable to accept these historical and present facts, we are prone to make bad decisions on behalf of future generations.  From the 1840s to present time we do have sufficient records to support the variability of stream flows within the MDB. One of these is at Wagga Wagga where records have been kept since 1844 and show that there have been 77 floods over 8.23M. Note a flow of 3,000 mgs. /day is a river reading of approximately 1 metre at this site.

To stress the point, the Murrumbidgee at Wagga has to rise 7 metres above normal flow to reach flood level and water the floodplain. This requires volumes far in excess of any storage on the system.

Ron Pike now lives at Coff Harbour on the NSW Central Coast in Australia.  Read Part 1 here.  Photograph of the Murrumbidgee River at Gogeldrie taken on September 3, 2008.

While it is easy for modern man to pass this off as superstition, much of what is being claimed in relation to the rivers of the Murray Darling Basin is as unreasonable as a belief in Bunyips.

To begin to understand the ecology and the unique environment of the Murray Darling Basin, we need to revisit some of the observations made by the first explorers after the arrival of white man in Australia.

Shortly after the settlers made their way across the Blue Mountains in 1813, a Government surveyor, Mr. Evans was sent on an expedition westward to find rivers and water, sufficient for settlement. He found and named the Lachlan and Macquarie rivers and a number of tributaries. He notes in his journal:

“The greater part of these lands are nearly free of timber and brushwood and should meet every demand for the Colonies extension of tillage and pasture lands for a century to come.”

On a later excursion when the land was in drought Evans notes:

“Rivers such as these no man has ever heard of before. They all run inland. They stop when least expected, leaving no visible channel or water-course. Sometimes they are as salty as the ocean and at other times contain excellent drinking water. From my observations it is apparent that they can go from a chain of stagnant ponds to boiling over their banks, filling whole valleys with raging water.”

To resolve the riddle of the two rivers discovered by Evans, the Governor dispatched in 1817, Lieutenant Oxley and botanist Alan Cunningham to follow the Lachlan and if possible also the Macquarie.  According to Oxley’s journal:

“We reached the Lachlan on the 26th April 1817at a place where it is about 100 feet wide, with deep banks, and its course obstructed by many large trees that have fallen into the stream, obstructing the current and rendering progress difficult. Flood marks thirty-six feet above the stream were clearly visible.”

After making their way down the Lachlan, Oxley and his party are eventually stopped by the swamps of the lower Lachlan valley only a day or so short of discovering the Murrumbidgee.

They retrace their steps back up the Lachlan until the 1st of August 1817,  when they head north to the Macquarie and then back to Bathurst.

In 1828 with the Colonies expanded stock numbers are all dying as a result of extended drought, Governor Darling sends an expedition led by Charles Sturt and Hamilton Hume to return to the Macquarie marshes found by Oxley, in search of pasture for the dying stock.

They reach the marshes on 26th December 1828, to find them dry and denuded with the barest trickle of water. This was in stark contrast to what Oxley had described ten years earlier.

They head north and on the 4th February 1829 in Sturt’s words:

“We discover a fine river about 240 feet wide, deep and covered with wild fowl. Much to our astonishment the water is so salty that our thirsty horses refuse to drink.”

The party proceeds downstream and discovers the Bogan River and replenish their water supplies. The party then proceeded to the Castlereagh River which was totally dry and Sturt described thus:

“So long had this drought continued, that the vegetable kingdom was annihilated. In the creeks and rivers, weeds had grown and withered and young saplings were growing in their beds. The larger trees on the banks were drooping and many appeared near dead.”

by Ron Pike, Coffs Harbour, Australia

The Picture is of the Castlereagh River at Gilgandra taken by Ron Pike in September, 2008.

If we convert the average annual rainfall into megalitres and do the same for the other continents, then yes, Australia does receive the least precipitation of all of the inhabited continents.  This is exemplified by comparing some average runoff data.  Of all of the rain that falls on Australia about 11% finds its way to the sea via our river system, which on average amounts to 290 million megalitres per year from mainland Australia. Another 50million megalitres runs to the sea from Tasmania.   By comparison the Mississippi river alone in USA averages a discharge of 560 million megalitres annually – almost double all of the rivers from mainland Australia. The Yangtze Kiang in China discharges 690 million megalitres annually and the Amazon in Brazil nearly ten times that amount.

So, yes, Australia does have meager water supplies compared to the other continents, but these figures lack relevance unless we consider two other vital factors. Australia is the smallest continent and much more importantly we have a miniscule population in comparison to other continents and countries. 

If we look at a comparison of water availability per head of population, which is much more relevant, we get a dramatically different picture.   Water per person from annual precipitation from various countries:
Australia:  130 megalitres
Brazil:  121 megalitres
United States  29 megalitres
China:  11 megalitres
Japan:   5.9 megalitres.
United Kingdom:  2.6 megalitres.

Leaving aside ground water for now, Australia has another source of water.   Because most of our cities and towns were originally built on river estuaries, for obvious reasons and because no thought was given to the collection of runoff from roofing and pavement, most of our storm water runs into the sea.   While the quantum of this is not known, estimates of around 40 million megalitres annually are considered reasonable. 

So, how much water do we need?

For each Australia household to have all the water we need to live what we consider to be the Australian lifestyle. That is, have a garden with lawn on which we wash the car when we feel like it, have a pool for the kids and generally not have to be concerned about water.  We need 110,000, litres per person per year.  That includes all domestic use, Council and industrial use, but does not include Agriculture and Mining.  Therefore for every 9 people in Australia we need 1 megalitre of water per year.

Let us assume that with some rational planning we did the following:
A. Collected and recycled just 5% of urban runoff = 2M megalitres
B.  New dams to collect just 5% of river runoff      = 14 M megalitres.
Total 16 million megalitres = sufficient for 144 million people.

So, Australia is not short of water, but incredibly short of practical planning and intelligent use of this resource. 

Radical environmentalism has distorted our capacity to make rational decisions on how we harvest and recycle this resource in the interests of all Australians.

Let us look at this from an extraterrestrial viewpoint.

If there were intelligent aliens orbiting the earth and looking down on Australia, they would certainly recognize that a large part of our continent is dry and a rugged place to live. But they would also note that the coastal strip from Adelaide to Cairns was sparsely populated with beautiful clean cities and towns, enjoying a wonderful lifestyle. All built on river and creek estuaries.

They would note that while these rivers did not have huge mountain catchments like other continents, they nonetheless had mostly pristine catchments that delivered regular stream flows.

They would also observe over time that the streams that served this naturally wonderful area in which to live, regularly had excess flows and on an irregular basis carried huge floods to the sea.

They would then learn from our media that these beautiful cities and towns were regularly short of water.
They could only conclude that the people who lived in this wonderful part of the world.  Lacked basic intelligence!  They could not reasonably come to any other conclusion.

Should you think this is a harsh criticism, let me give you an example from my home area on our wonderful coastal strip at Coffs Harbour.

Since arriving here in 2002 most of the towns both north and south of Coffs Harbour have had water restrictions. Coffs Harbour uses approximately 5,500 megalitres of water per year.

Since our arrival in this wonderful part of the world, the Bellinger River (a small river, average discharge 240,000 megs/year.) has been in flood three times. In March 2006 a flood in this river was flowing over the top of the bridge at Bellingen at the rate of 72.000 megalitres per day, sufficient flow if harvested to keep Coffs Harbour in water for 13 years.

This is just one small example of the water harvesting opportunities that can be shared with hydro electricity generation in Australia on many streams.

It needs to be shouted from the rafters and repeated over and over, that in the Australian environment, correctly sited, properly engineered and sensibly managed dams and water storages are never other than a plus for the environment.

There is no environmental downside.

Properly managed water storages, augment stream flow in drought, they do not deplete flows.  Water saved from flood flows is there for mankind to use to best advantage, for the environment, for community consumption, for hydro power, for agriculture and fishing and for leisure activities.

Water is not scarce, it is perpetual.

Australia is not short of water, but we are short on practical planning and the intelligent use of a basic resource.

Ron Pike
Coffs Harbour, New South Wales