![\"The](\"https:\/\/wombatforestcare.org.au\/wp-content\/uploads\/Source_of_Coliban_2-1.png\")
The Coliban downstream of Trentham Falls (photo by Alison Pouliot)<\/p><\/div>\n<\/div>\n
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 \u2018Coliban starts here\u2019. It\u2019s solid bush – tough going through surprisingly rough terrain that involves climbing, crawling and extracting large hungry leeches from places you\u2019d rather they weren\u2019t. This is not the first time I\u2019ve sought a river\u2019s source and somehow it doesn\u2019t seem to become any easier. Most rivers begin their life high up in the world\u2019s 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\u2019s not raining or hasn\u2019t 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.<\/p>\n
My boots are getting wetter and I find myself in a swamp that may just well be the source of the Coliban River. I\u2019m somewhere in the Wombat Forest not far from the township of Lyonville at just under 700 metres altitude. The river\u2019s 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\u2019re 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\u2019re 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.<\/p>\n
The river\u2019s 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\u2019s spelt the end of the Coliban\u2019s natural flow regime. The river\u2019s 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\u2019s catchment, restore riparian vegetation and improve stock management.<\/p>\n
Tracking the source of a river will take you on a journey in more ways than one. If you don\u2019t find the source, the hunt is still worthwhile, as you\u2019ll always discover something, even if it\u2019s not what you\u2019d expected. The reality is that a river\u2019s source is not static. It depends on when and where rain falls. Or if indeed it does fall at all. But an afternoon\u2019s adventure in some of the Wombat\u2019s 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\u2026.<\/p>\n