Month: July 2018

Big Barwon River Walk

in 2013  a group of enthusiast Landcarers, led by Jennifer Morrow, set out to walk the length of the Barwon River from its source to the sea. The attached Report records the Group’s traverse of the sector from Inverleigh to Merrawarp in 2016

Authors Peter Greig and Mandy Baker acknowledge the important contribution made by the Barrabool Hills Landcare Group to this venture.

Barwon Walk 2016

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State of the Barwon River

The enclosed article was extracted form the Upper Barwon Landcare Network’s “Tree Talk” Newsletter, Winter 2018 edition. It was written by UBLN President Peter Greig.

Peter Greig. Photo courtesy Tony Baldwin

HELP NEEDED FOR BARWON RIVER

Report from the UBLN Barwon River Subcommittee

Peter Greig

Two recent crises galvanized public attention to what has been obvious to some for many years: the Barwon River – particularly upstream from Inverleigh – is in trouble. The first and most dramatic event was an extensive fish‐kill in mid‐2016; the second is the river going dry in summer regularly in recent years. Much has been happening as a consequence of these events, mostly quite encouraging, but more needs to be done. This note summarizes recent actions, and canvasses some future possibilities. But first, a little background.

Context

The Upper Barwon River provides much of Geelong and district’s water. The West Barwon Reservoir (21 Gl) supplies much of the annual consumption from the Barwon catchment (13 Gl/yr), but this is only a fraction of the total stream‐flow (300 Gl/yr).

Geelong’s increasing population and a big drought in 1982‐3 required additional water sources, particularly groundwater from Gerangamete (currently licensed at up to 20 Gl/yr but 4 Gl/yr on average). Urban and industrial consumption accounts for most usage (10 Gl/yr); irrigation about 20 per cent (3 Gl); and rural usage about 3 per cent.

Evaporation from Wurdi Boluc storage reservoir is estimated to be 2.2 Gl/yr on average, while loss from channel leakage is about 0.3 Gl/yr. What is not clear is how much overland flow is diverted into farm dams built after the 82‐3 drought. Land‐clearing, too, has had an impact, by increasing overland flow from winter rains, and reducing summer flows from infiltrated groundwater, but no estimates of this are available.

As to river health, it was clear even in 2006 that over‐extraction was causing river health problems, and an “environmental bulk entitlement” of 1 Gl/yr from West Barwon reservoir was promised by State government, pending supplementary supplies being found for Geelong (such as connecting to Melbourne’s system).

That promise has recently been realized. Apart from overextraction and land‐clearing, water quality in the Barwon and tributaries has been poor, due to stock access, contaminated run‐off, and carp, which now dominate all other aquatic species. Emphasizing the point, in 2010 the Barwon’s Index of Stream Condition at Birregurra was “poor” on a five‐point scale ranging from “very poor” to “excellent”.

Nearly 80 per cent of the whole river was classed as “poor” or “moderate”. This is no surprise to locals like Jim Lidgerwood, who recalls that, as a boy, the Barwon at Winchelsea was fishable throughout the summer.

As if all that wasn’t enough, climate change is expected by all scientific accounts to exacerbate the situation, by reducing annual rainfall, and making summers longer and drier. Clearly, something needs to be done.

Groundwater Extraction

Gerangamete borefield was contentious from the start, mainly because licensed extractions exceeded the aquifer’s sustainable capacity, which is only 1.5 Gl/yr according to estimates by former government hydrologist Roger Blake (now a community member).

Loss of groundwater and stream‐flow in the Barwon and tributaries (particularly Boundary Creek) was the expected consequence, but no one foresaw the acid sulphate problem that emerged on Boundary Creek. Even then, that problem was only identified by community activist Malcolm Gardiner, who with Roger Blake then linked the problem to a fall in groundwater levels caused by pumping from Gerangamete borefield.

Barwon Water and other relevant agencies were initially skeptical that the borefield was to blame for acid in Boundary Creek. But following formal representations by Roger and Malcolm, Barwon Water has since publicly acknowledged their partial and unintended culpability. Moreover, they are considering putting a hold on any future extraction until the acid problem is remediated.

And further, they are contemplating extraction as a last resort (except in an emergency), until a sustainable yield is verified, and then only based on the “precautionary principle”, that is, testing for surface impacts like loss of stream‐flow and managing licence conditions adaptively as more information comes to light.

Taken together, these statements clearly show Barwon Water is deliberately balancing customer welfare against river health and community perceptions, consistent with their “zero waste” and “zero emissions” goals. For that corporate social responsibility, they deserve full credit.

Environmental Water

Minister Neville recently announced the I gigalitre per year entitlement for the Barwon River from West Barwon Reservoir, and Corangamite CMA has responsibility for deciding on its deployment to achieve improvements for targeted aquatic species, depending on their seasonal needs. To help with this, and to bring the community along, an advisory group has been created to include stakeholders (including UBLN).

As well, CCMA has engaged a consultant who did the ecological research leading to the specification of the entitlement back in 2006, as part of the Central Sustainable Water Strategy. All concerned are grateful that the 1 Gl/yr entitlement is better than nothing, but aware that it’s a long way short of what might bring the ISC up a grade or two. (It was mentioned that 22 Gl/yr might be needed for that).

Nonetheless, it may be possible to improve breeding conditions for species such as platypus.

Acid Remediation

Acid sulphate soils in Big Swamp on Boundary Creek (between Colac–Lavers Hill Road and Colac–Forrest Road) became active when the swamp dried out, mainly due to groundwater extraction at Gerangamete, and partly due to drought, and a fire. Now Boundary Creek downstream has a pH of less than 4; the water is crystal clear, and not a living thing can be seen. Livestock won’t touch the water, which is a major problem for graziers like Nellie Shalley, who depends on the creek for stock water.

Barwon Water is taking measures to provide alternative stock water, via a dedicated stock‐water pipeline, and has provided 2 Ml/day of supplementary flow to the creek (to compensate for an expected loss of groundwater from borefield pumping). Even more importantly, it is committed to finding a way to stop the acid flow.

A community consultation group is being formed (including UBLN) to work alongside Barwon Water personnel in this endeavor. The challenge shouldn’t be underestimated: Southern Cross University experts that Malcolm Gardiner brought in to confirm the acid sulphate problem estimated that neutralizing the acid

with lime or gypsum would require an expenditure of around $6mn. Other methods are likely to be used.

Meanwhile, Environment Protection Authority policies on river contamination are being revised. It is still unclear to me if EPA has jurisdiction in the acid sulphate episode. If they do, then Barwon Water would have legal as well moral as (sic) reasons for fixing the problem.

Land Clearing

Much of the Barwon’s catchment has long been cleared of tall vegetation, creating space for farmland and settlements. The impact on river health is obvious: ISC ratings are low in cleared catchments; high where the land is still forested.

In recent years, vegetation clearing has been regulated, and much re‐vegetation has occurred, by landowners, landcare and catchment managers, often concentrated on stream‐sides. Still, as those who walked the Barwon’s full length know, much remains to be done. As well, in the catchment’s hillier parts, gullies are still actively eroding and sending sediment downstream. Re‐vegetating such places is

still a big job worth doing.

Birregurra Creek

Another source of contamination in the Barwon comes from Birregurra Creek, which now carries salty water from the Lough Calvert drainage scheme, designed in wetter times and managed as required to prevent flooding of farmlands around Lake Colac.

These days, this isn’t such a problem, as low rainfall has kept the lake level low. Again, whether the EPA has jurisdiction over such contamination is unknown to me.

Walk The Barwon

Walking the length of the Barwon from source in the Otways to the sea at Barwon Heads is an adventure completed by a group between 2014 and 2017. Jennifer Morrow conceived of the idea, and inspired the group, which varied in composition and number from 12 to over 60, with much help from several landcare groups and funding from CCMA.

Mandy Baker did much of the administrative work, and with Jennifer and Lachie and Janet Gordon, is in the final stages of producing a book on the journey.

Walkers came away with a rare sense of the river’s interactions with those living and working nearby, including graziers and dairyfarmers, of course; and townsfolk in Birregurra and Winchelsea, Inverleigh and Geelong. As importantly, too, walkers got some sense of the first nation’s peoples, and their dependence on the river. The book should be a permanent record of these historical insights.

Platypus Monitoring

For an iconic species, platypus are remarkably hard to detect: they find their food underwater, and live in tunnels above water, but with entrances underwater. Thus they avoid above‐ground predators, like foxes and feral cats. Obviously, if the river dries out in summer (platypus breeding season), they are more vulnerable.

Until recently, detection has been a laborious process of trapping, tagging and release. New technology replaces all that by simply detecting DNA in water samples, thus increasing both efficiency and accuracy. With financial help from Barwon Water (and possibly CCMA and Wettenhall Environment Trust), a platypus DNA detection project is about to get underway, which will supplement the ISC surveys (usually five‐yearly, but not done since 2010). It is expected that platypus monitoring will add to the impression that the Barwon does indeed need more help than it’s getting.

Carp

Carp now dominate all other species in Barwon River and tributaries ‐ they’re like rabbits on land. They nullify most of the benefits of environmental water flows, which help carp‐breeding, but not the target species.

Happily, a potential remedy is under consideration, not unlike myxomatosis for rabbits: a natural virus specific to European carp. The risks from such a remedy are easily identified, not least the creation of a massive waste problem from hundreds of tonnes of dead fish, and the possible impact on non‐target species. These risks are being carefully assessed by government and university researchers under a National Carp Control Plan, and no action will be taken until all states, territories and the Australian government agree. But at least there’s hope on the horizon, and a much brighter future for the Barwon, if it works out.

Conservation Action Planning

How should these various aspects of Barwon River health be brought together coherently? By chance, a method has become available: it’s called Conservation Action Planning. It’s been used internationally for several years, as well as in Australia, where specialist facilitators are available. Fortuitously, UBLN had State funding for its application, as an example of how landcare can work more collaboratively with its regional and State partners (like CCMA, Barwon Water, Southern Rural Water, and Shires) CAP requires participants to identify major assets of concern.

Unsurprisingly, the two chosen were (a) the Barwon River and its catchments, and (b) the communities that interact most closely with the river.

At present, participants are working through a process of identifying what specific and feasible things should and can be done to achieve measurable improvements in both the river’s health, and the communities’ capacity to help do that. This promises to be something other than those glossy strategies and plans that are regularly launched and quickly forgotten.

One of the practical outcomes under consideration is a Friends Of The Barwon group. The aim, of course, is to expand awareness of the Barwon’s plight to a wider group of sympathizers, particularly (but not only) water consumers, whose individual choices could make such a difference to the situation.

Conclusion

Yes, the Barwon needs help, and probably more than is generally understood among citizens and corporates that could help make a difference. Signs of willingness to help are already in the wind, and such efforts must be encouraged, like Barwon Water’s to deal with the Boundary Creek acid problem. In time, studies on how best to deploy environmental water may reveal how much more is needed to be effective; but for now, making the best of what’s available is the best pathway. In the end, garnering public support for individual and collective action to improve the river’s health is probably the most pressing and obvious thing to do.

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