Hydroecology

Hydrology, Ecology, Ecohydrology, Hydroecology, Environment…A battle over the science

Central to the understanding the war over the water in the Kangaloon Aquifer, is knowing what effect mining the groundwater might have on the environment. This requires an in depth knowledge of hydrology, geology, ecology and perhaps more fittingly, an understanding gained through the more recently evolving interdisciplinary field of ecohydrology. Once the consequences of drawdown of the aquifer water is understood, only then can we begin to assess the fairness of the aquifer project and how or if this water might be shared.

A narrow, short term view may be to look at the immediate impacts of such action, but water, like all things in the intricately complex thing we call “nature” does not exist in isolation, nor is it confined to one geographic location, nor does the cyclic way it interacts in the biosphere and moves through its different phases occur in a neatly defined time frame. What we alter in one time and place can have far reaching effects in other parts of the planet, and sometimes these effects are not obvious in the immediate spatial and temporal sphere.(15)

Understanding the Science

Hydrology is the science that encompases the occurrence, distribution, movement and properties of the waters of the Earth and their relationship with the environment within each phase of the hydrologic cycle. Hydrology has evolved as a discipline in response to the need to understand the complex water system of the earth and help solve water problems. If you can familiarise yourself with some knowledge of hydrology, then 1) you can read the reports generated about the aquifer and 2) you can make your own mind up about the soundness of the science. (16)

Water Cycle

Water Cycle

The Hydrologic Cycle in Kangaloon

hydrology
There was not a lot of available information about the hydrologic cycle of Kangaloon and the place of groundwater in this cycle, until 2003, when in the grip of drought, Sydney Catchment Authority commissioned a “desktop” study of the area to determine whether pumping water from the aquifer for use in Sydney was a viable option. This was investigated further by studying the topography and geological settings, studying of any available data from existing agricultural bores in the area, some test drilling was done and data collected from a number of methods for use in modelling and determination of water yields and quality, all presented to the public in a simplistic report, with scant data, and with no references! (8)

Kangaloon is located in the Sydney basin, which extends from the southern town of Braidwood, to Gosford, in the north, and framed by the Great Dividing Range to the west, the Pacific Ocean to the East, an area dominated by mountain landscapes and deep gorges eroded by streams and rivers. These structural features combine with different rock types, producing joining patterns which control water drainage in the gorges and swamps. It is these interlinked gorges and rivers that form the catchment area for Sydney’s water supply. (17)

Kangaloon sits on the tableland just behind the magnificent Illawarra Escarpment. There are pockets of subtropical rainforest below the cliffs, and some remaining cool temperate rainforest scattered around Kangaloon and the adjoining village of Robertson. (18) The escarpment captures moisture laden clouds that drift in from the ocean, and the cooler air of the higher mountains converts rising mist into “orthographic” rainfall which maintains the moisture necessary for the maintenance of the remnant tableland rainforests, shale woodlands and the rich agricultural land cleared by early settlers.

The high rainfall of the district is captured in the wetlands and rivers, which are part of the catchment area. It recharges the groundwater reservoirs, which in turn maintain the wetlands and feed the springs of this fertile area. The wetlands play a vital role in maintenance of the local ecosystems and in filtration of water which flows into the rivers and local water catchment dams.

Groundwater doesn’t exist in a giant subterranean lake as many people imagine (“Journey to the Centre of the Earth” was a Jules Verne fantasy). Rather it lives in the many layers of different rock types that exist beneath the ground. Imagine it a bit like a giant licorice allsort, some of the layers are soft and porous, like a “rock sponge”, and these can hold a lot of water. Some of the layers are impermeable, and prevent water from getting from one layer to another. In many places the rocks are fractured, folded, melted, or have vertical intrustions of different types of rock which act as channels between the layers. When you drill a thin bore hole deep through the rock layers, water seeps into the cavity that has been created and can be pumped to the surface. You see our licorice allsort model is somewhat limiting. Geologists and hydrologists use models to try to understand and predict what is happening in aquifers, but their models have limitations too.

The groundwater within the hills surrounding Kangaloon exists in shallow basalt aquifers, with mostly modern water (less than 50 years old). These feed the springs and upper creek systems. The deeper sandstone aquifers may be recharged by rain which falls directly onto exposed sandstone areas where there are sandy soils and deeper still, there are vast reserves of fossil water (up to 11,000 years old) . The underground water reserves naturally flow north and are discharged into streams which eventually flow into the Nepean and Avon Dams. (9)
It’s a majestic, self maintaining system, which even with the amount of human interference in the past 150 years, still supports many small farms, a dairy industry, wetland and woodland ecosystems, with water aplenty to be captured from surface runoff when it rains, and sent off to Sydney and the Illawarra.

A Plan to Move Water a Bit Faster.

Test bore "the fountain" aerating to get rid of iron

Test bore “the fountain” aerating to get rid of iron

2006 was a big drought year, it had been drought since 1997. Dry in Sydney, dry in the catchment areas, and dry in Kangaloon. The dams were down to 40% capacity, the land was parched, the environment, farming community, landowners, politicians and businesses were stressed. (19) The plan was, after a short period of trial pumping, to install 50-60 big pumps in groups of 10, about 500 meters apart, pump billions of litres of water, through pipes and discharge it into streams which would run into the Avon Dam. The plan was to “drawdown” about 10% of the storage capacity of the aquifer, and then leave it to recharge over the next 7 years. (8)

On the surface, it sounded fair enough, except that studies were so preliminary, rushed and incomplete. The short term trial showed a significant lowering of the water table, even up to 2 km away from the trial pumps, impact on flows of streams and creeks and at least one of the upland swamps. Recharge, the impact on private farm bores, local springs and the general environs could only be estimated, as there was no significant rainfall (being a drought), and most of the predictions were from “modelling”. Moreover, proper studies had not actually established the size of the aquifer, whether the water in it really was modern or fossil (that being the case, recharge from rain was never going to replenish it any time soon), what the effects of draining it would be, and when or if the aquifer or the surrounding ecosystems would ever recover from the “drawdown”. (20)

Opponents of the project disagreed with the model assumed by the SCA, that the aquifer was “confined”, and that drawdown wouldn’t effect groundwater from other areas. Other models suggested that part of the recharge of the aquifer came not just from rainfall, but from the shallower groundwater in the basalt layer (the one that feeds the springs and rivers) and even after rain, the aquifer was not recharging, but water from the deeper sandstone (fossil water) was just seeping back in and recharging the bores, not actually recharging the aquifer. In fact even preliminary reports suggesting widespread environmental impact were dominated by technical details which assumed the project was to be undertaken. (21) Continued trials were problematic due to the large amount of iron being extracted, which would require the construction of settling ponds to precipitate the iron prior to the water being pumped to the catchment. The biggest problem with these studies was the haste with which they were being carried out.

Iron Sludge spilling from a settling pond Image; Denis Wilson

Iron Sludge spilling from a settling pond
Image; Denis Wilson

According to the SCA Project Description and Preliminary Environmental Assessment Report “the government has determined that design and environmental assessment should proceed quickly so that it has the capacity to commence construction of the borefeild as water supply levels have fallen below 40%”.

The benefit of hindsight shows us that this very same report, which urged proceeding quickly on the project was based on fundamental errors and assumptions about the structure of the aquifer and how it recharged.

The Kangaloon Water War erupted because this report was generated prematurely, and omited advice from the SCA’s own consultants which drew attention to the problemsassociated with the project. Following intense community scrutiny, deployment of independent hydrological investigations, the models were altered and testing continued. Local residents, through their much longer term observations, were not blind to the convenient oversights in the data, and persisted with their opposition to the project despite the political and institutional weight behind their opponents.

It’s hard not to be biased, but it seems rather obvious, that if the water was heading to the Nepean and Avon Dams anyway, protected, clean, filtered, not subject to high evaporation rates in drought time, and along the way still maintaining wetlands and farms already stressed by drought, then why would anyone even consider installing pumps, settling ponds, power supply, pipelines and other infrastructure, at a cost of $100 million, when the water would get there itself, free, clean and maintaining ecosystems rather than damaging them?

Ecology
Ecological studies were dramatically ignored in this process.

Ecology is the study of natural environmental systems, an academic discipline not to be confused with environmentalism or environmental science. Ecosystems sustain every life supporting function on the planet, including climate regulation, water filtration, soil formation, erosion control and many other features of scientific, historical and spiritual value, including production of food and medicinal substances. (22)

Kangaloon Sun Orchid, Endangered Wetland Species Image: Denis Wilson

Kangaloon Sun Orchid, Endangered Wetland Species
Image: Denis Wilson

In the 2006 groundwater technical report (21) , only 1 out of 72 pages was devoted to ecological impacts, with scattered references for the need for ongoing monitoring of ecosystems.

The main ecological studies gave listings of species and endangered species, and all emphasised the likelihood of disruption of wetland ecosystems and the need for further ongoing study and monitoring, particularly in different seasons. Many species were not listed as they couldn’t be observed at the particular time of the surveys.

One of the local wetland ecosystems which had been extensively studied was the Wingecarribee Swamp, which had suffered massive degradation in 1997. (23) There has been ongoing monitoring of this wetland during attempts to rescue and rehabilitate the collapsed swamp, and so there was much ecological information about the flora and fauna of this environment, including migratory species. What wasn’t known however, was whether this wetland was connected to or dependent on the Kangaloon Aquifer or part of another system. It was this uncertainty that allowed intervention from the federal government to protect endangered species of this and the other local wetland areas. Although ultimately all natural systems have some connection, it is now thought that the Wingecarribee Swamp area is not connected to the Kangaloon groundwater, but research is still ongoing.

 

 

Image: Fairfax Media

Image: Fairfax Media

Ecohydrology is an interdisciplinary field which brings together many disciplines to study connections and interactions between hydrology and ecology. In terrestrial ecosystems, the interactions among vegetation, land surface and groundwater are the main focus. (24) Could a more integrated ecohydrological study of the aquifer have been more appropriate?
Independent ecohydrological studies, not just those commisioned by the SCA, may have assured those who sought to protect the aquifer and the surrounding environs, that the authorities responsible for water management had a better understanding of the consequences of establishing the borefeild, and tensions may not have erupted so early in the process. And how would it change things if the first study was ecohydrology, and then a feasibility of water extraction for urban use, only if it was deemed safe for the ecosystems to do so? This is still an uneasy perspective for many, reserving a place for humanity as part of the ecosystem, rather than humans as manipulators of natural processes.

Fair Distribution
How do we determine what was fair in this scenario?
What can hydrology tell us about fair distribution of water?

Water is needed to maintain a balance that nature has shaped over millions of years, to maintain what has been created. If we ignore factors such as the rain creating properties of rainforest, moisture maintaining groundwater systems and the interdependencies of ecological systems, then we disrupt not only localised ecosystems, but also contributed to the disruption of global systems. Large scale intereference with nature in this regard is not particularly fair to all life forms which depend on established natural cycles (including humans), it is unfair to future generations who will live with the consequences of such actions.
Is it fair that millions of Sydney residents and businesses do without water, when there are untapped reserves that can supply their needs? Maybe not, but at what point do you risk desecration of one region to ensure ongoing maintenance of another? Surely not until you have a proper understanding of the risks you are taking to do that. It was abundantly clear that not enough was known about the hydrology or ecohydrology in this case.

Beyond the Science

I want to share an enlightening experience, which has confirmed for me, the approach humanity may need to consider, if we want a long term future in a beautiful, habitable world.
I am a trained biologist. Having lived in the country, I have developed a relationship with the natural world. But I don’t know much about hydrology, or geology. Through my interdisciplinary project, I embarked on a “desktop” study and familiarised myself with some fundamentals of how water exists on our planet.

I then read many hydrological reports related to what had been happening in Kangaloon 6 years ago. It hasn’t changed in that time, so I took my little boy and camera, and drove around the district to find some of the places described in the reports. It is odd to be doing a study on water that you can’t really see. Most of it is under the ground!
It’s a beautiful area and I found myself randomly taking photos of pretty spots along the way. However, I made a start on this page with my new found knowledge of confined aquifers, perched water and fractured rock strata. When looking at the issue through the lens of history, I met a local naturalist who took me on another, more informed guided tour. We set off, stopping to take photos of tree covered hills, gulleys and water courses, odd rocky outcrops, a wombat hole, creeks and lush fields, as he explained everything about the aquifer, how it had formed, where it was, it’s relationship to the water and all life forms around us.

This was the amazing bit. Every photo we took, I had taken several weeks before, from the exact same spots, every single one. Miles from the place to be drilled for water. It was a moving experience realising that intrinsically, we have an intuitive connection with the natural world, as what I had captured in innocence, were the places where water from deep beneath the earth interacts with water and life above. The places where ancient volcanic basalt dykes interrupt the water filled sandstone stratas below, where tree lined roads followed prehistoric fault lines, and rows of remnant rainforest trees are thriving on springs where water in the shallow aquifers bubble up to sustain farmland which was once all temperate rainforest. I believe we all have this connection, we just somehow ignore it or don’t recognise it. We have just lost our place in the natural world, and so we forget that water is a part of us, and we should be at one with it. When we drink, water flows to every part of our body, it becomes “us”. No wonder water is sacred to every civilization. And no wonder that for the deepest reasons, it is something we are prepared to fight for, and ultimately share.
As well as my spiritual experience, I also learned there is nothing like local knowledge and that desktop studies are rather limited when we want to really get to know the natural world.

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