Of fires and floods

My family owns a bush block in the Arm Valley, a tributary of the Upper Mersey. Some 50 acres in area with a river frontage, it was an artefact of the old days having been originally selected around 1910 for its hunting/grazing values. We bought it in 1989 in a bit of a neglected state. It had been selectively logged some decades before and was littered with stumps, heads of trees and assorted regrowth. Over the quarter century we have owned it, we have cleared it up a bit, built a shack on it and enjoyed the quality of life it provides. To date, four generations of our family have revelled in its splendid isolation. Dominant memories over that time have been playing in the river on hot days, sitting around a fire pot outside on fine nights, cooking meals by candle light on the wood fired stove, gathering firewood, going for walks on cool clear mornings, deciphering the patterns and ways of the wildlife, watching the aurora australis in the still night sky, spotting trout in the river and enjoying the company of family and friends. Our experiences at the Arm have enriched our souls and given us a wider perspective on life. Events over the last few months, however, have served to remind us just how precious these experiences are.

First in February, catastrophic fires provided a very real threat with the Arm Valley caught in a pincer like grip between two fires - the February Plains fire and the Lake Parangana fire. Igniting on the western side of the plains, the February Plains fire roared eastward across the plains and descended into the Arm Valley. At the same time, the Lake Parangana fire spread southward down the side of the lake and began climbing the northern slopes of Maggs Mountain. I remember checking the Tasmanian Fire Service fire maps on a daily basis and registering with growing concern the way the two fire fronts were steadily getting closer and closer to our block - one from the west and one from the east. Luckily, the rain came and doused the flames leaving me thinking that but for perhaps one more disastrous fire day, flames may have roared up the valley and wiped out our beloved shack and many of our precious memories.

FIre situation 12 February 2016. The private property blocks at the Arm are predominantly in the light coloured area between the two (dark) fire fronts level with the top of Lake Rowallan.

We had little time to register our relief at our close encounter before nature played another, perhaps more dramatic, hand. In early June 2016, much of the east coast of Australia experienced very heavy rainfall as a result of an extensive upper-level trough and the formation of an East Coast Low complex in the Tasman Sea. Record rainfall resulted in flooding in many areas stretching from southeast Queensland, eastern New South Wales, eastern Victoria, and large areas of northern Tasmania. Heavy rainfalls in the Mersey catchment, measured at 400 mm of rain in the period 5 to 6 June, caused extensive damage around Kimberley, Mersey Lea and Latrobe.The speed and severity of the floods caused by this rainfall tragically resulted in loss of life, and devastation to hundreds of families, businesses, farmers and local communities, and the social, economic and financial cost is extensive. In the Upper Mersey, that almost unprecedented volume of rain fell on predominantly steep landscapes whose vegetation had only been recently burnt. A number of outcomes resulted. Large amounts of soil, peat and ash washed off the slopes destabilising vegetation and causing significant erosion. Sodden soil on steep slopes also led to large landslips. Two slips, for example, occurred on the Mersey Forest Road between the Lake Mackenzie turnoff and the bridge over the Mersey at Lake Parangana. It is difficult to image how the washout at Martha Creek can ever be repaired.

Martha Creek washout, 2016, Rod How photo

Then we learnt that there had been a large slip covering both the Maggs Mountain and the Arm River Roads. This slip has effectively blocked access to our shack with the only limited access into the valley being, ironically, an old stock route created in the 1850s and only decommissioned in the 1960s. It is not known when we will be able to regain normal access to our shack. Some say it may be months. The third impact, and one that is yet to be quantified is the impact on cave systems near Liena. The photo of the Croesus Cave entrance taken by Rod How that shows a mass of boulders held behind the steel gates suggests that many cave systems may be full of stones that may have been thrown around like clothes in a tumble drier. I am fearful that cave formation that may have taken centuries, even millennia to form, may have been destroyed in a maelstrom that might have lasted an hour or two.

 

Maggs Mountain landslip covering both Maggs Mountain Road (top) and Arm Road (bottom), 2016, Rod How photo

 

Rocks behind the gate at Croesus Cave, 2016, Rod How photo

These two extreme natural phenomena, happening so close together, have wreaked havoc on a treasured landscape. While our mountain retreat is safe, the events of the last few months have served to remind us just how precious it is.