In search of the source of the Coliban
Words and Images By Alison Pouliot
The source of a river is where it all begins. The journey. The movement of water, of energy, of life, across landscapes. It may also be a personal journey, of wonderment and intrigue, into uncharted territory. But have you ever actually tried to locate one of the Wombat’s six river sources? River sources are often both elusive and transient, especially in a land with such intermittent flows. Contrary to the linear geographic feature with a defined source and mouth on your map, reality usually presents rather a different scenario.
The swampy origins of the Coliban River
(photo by Alison Pouliot)
River sources have been the desired destination of endless pilgrimages. They’ve been mythologised by numerous cultures across the centuries. They are well-springs, origins, symbolic of beginnings, of new life, and hold a spiritual significance for many. Writers and film makers have romanticised great river journeys but how many of them actually located the source? River sources are usually found in some of the wildest and highest quality habitats of a river’s journey. Here you’ll often find wonderlands of exquisite beauty and havens for biodiversity. This certainly holds true for those rising in the Wombat, including the Coliban.
It’s one of those perfectly still and melancholic autumn afternoons when I set off in search of the Coliban River’s source. It almost feels a little like stepping into a Wright or MacKellar poem. In previous newsletters we’ve explored the Wombat’s southward flowing rivers and now we’re turning the spotlight on those that flow to the north. I’m armed with a swag of maps, compass, GPS and my head brimming with local, albeit largely contradictory, advice. I can’t help wondering whether a pocketful of rice might be more useful. It sounds like it should be easy to locate the highest point in the catchment and find the damp bit of earth where it all begins. Or perhaps an upwelling of groundwater. A spring. Some obvious sign of a ‘beginning’. You’d think it would just be a matter of locating a river channel and simply following it upstream until it vanished. Hmmm nice theory. And Google Earth doesn’t provide too many clues either. I slide the map into my backpack and decide to just follow my nose.
The Coliban downstream of Trentham Falls
(photo by Alison Pouliot)
Part of the difficulty is that elevation changes are subtle. The denser the vegetation the harder it is to detect these changes. And of course there is no defined track or convenient sign with ‘Coliban starts here’. It’s solid bush - tough going through surprisingly rough terrain that involves climbing, crawling and extracting large hungry leeches from places you’d rather they weren’t. This is not the first time I’ve sought a river’s source and somehow it doesn’t seem to become any easier. Most rivers begin their life high up in the world’s mountains. Following a snowfall or downpour, some moisture soaks into the ground and the rest gives way to the force of gravity, trickling downhill as surface waters. But if it’s not raining or hasn’t for awhile, things can be trickier. The source of a river may comprise a damp swampy area fed from either an underground spring or from runoff. Small braids or headstreams then gradually come together into a single channel that grows as it heads downhill.
My boots are getting wetter and I find myself in a swamp that may just well be the source of the Coliban River. I’m somewhere in the Wombat Forest not far from the township of Lyonville at just under 700 metres altitude. The river’s journey begins in lovely tall open forests of stringybark, manna gum, messmate, and narrow-leaved peppermint. A little further downstream it takes a tumble and plummets over the spectacular columnar basalt of Trentham Falls (reputedly the largest single-drop falls in Victoria). These impressive basalt columns formed as a result of rapidly cooling lava some five million years ago. The falls are the perfect spot to stop awhile and soak in the tranquility and majesty of the Wombat. You’re likely to spot swallows darting under the falls and perhaps a wallaby bounding through the undergrowth. At night the calls of Tawny Frogmouths echo across the valley. And if you’re also here in autumn keep an eye out for the beefsteak fungus (Fistulina hepatica) growing at the base of eucalypts and once a food source of Aboriginal people.
The river’s journey has hardly begun before its flows are captured by the Upper Coliban, Lauriston and Malmsbury reservoirs respectively. Along its course the Coliban meets with the Myrtle and Kangaroo Creeks as well as the Little Coliban River which all contribute to its flow. Its 90km journey concludes at the confluence with the Campaspe River at Lake Eppalock. The discovery of gold in the 1850’s spelt the end of the Coliban’s natural flow regime. The river’s course has since been regulated through a series of channels that supply water to major towns including Castlemaine and Bendigo. But despite these modifications the Coliban River still supports a diverse biota, especially in the upper reaches in the Wombat. This includes eight species of native fish, four of which are endangered. The critically endangered trout cod (Maccullochella macquariensis) has also been sighted. Various efforts are underway to link patches of remnant native vegetation within the Coliban’s catchment, restore riparian vegetation and improve stock management.
Tracking the source of a river will take you on a journey in more ways than one. If you don’t find the source, the hunt is still worthwhile, as you’ll always discover something, even if it’s not what you’d expected. The reality is that a river’s source is not static. It depends on when and where rain falls. Or if indeed it does fall at all. But an afternoon’s adventure in some of the Wombat’s most intact habitat promises to be a rewarding and enchanting journey. And if by chance you should get lost, just follow the trail of rice grains….