The Hume's 'Great Divide'

'It's so boring!' That's what you hear people say about the Hume, the national highway between Sydney and Melbourne.  Every town along the route is bypassed. I can drive from my home at South Melbourne, pass through one traffic light onto Kingsway, and reach the other side of the Sydney Harbour Tunnel before I hit the second traffic light of my journey to my daughter's house at Manly.

Driving door-to-door from South Melbourne to Manly, in the process crossing over the heart of Australia's two largest cities, can easily be achieved in under ten hours. That time includes several coffee stops. It's a stunning improvement on the bad old days. Even bored travellers will concede about the Hume that 'It's a great road trip.'

The Hume has a different name in each state (Hume Freeway in Victoria, Hume Highway in NSW), and nowhere is the full distance from one city's GPO to the other city's GPO signposted. As roadside signs prove, the distance depends on how far you've already driven from the central city before you see the first indication of the journey you've yet to make.

More and more people now take to the road in preference to the expense and hassle of flying ... but the Hume's reputation as a scenic drive, experienced at 110kph 'cruise control' along an easy road for so many hours, continues to generate that constant refrain 'It's so boring'.

I don't agree. There's always something new to see and think about along the way. For example, on my numerous trips along the Hume I've exercised my brain trying to work out where the Highway twice crosses the 'Great Divide', as distinct from the Great Dividing Range. Both terms refer to the drainage system for our rivers, some of which flow to the Pacific Ocean and Bass Strait and some of which flow inland. The Range itself extends for 3,500 kilometres, from far north Queensland through New South Wales to Western Victoria, and it has a huge influence on Australia's climate.

The physical presence of the Great Dividing Range as hills and mountains is pretty obvious. The actual line marking the 'Great Divide' is not at all obvious.  

At the Sydney end it's taken me a while to figure out where the road crosses the 'Great Divide'. After leaving Sydney and reaching Goulburn, you leave the hilly forested country behind and gaze over our 'sunlit plains extended'. Yet the Wollondilly River at Goulburn is still flowing towards the Pacific Ocean, as a tributary of the Nepean-Hawkesbury River.

Well beyond the Canberra turnoff, the next town heading southwards, Gunning, obtains its water supply from the Lachlan River, which the highway doesn't cross. The Lachlan River, which flows westwards as part of the Murray-Darling catchment area, eventually reaches the sea near Adelaide on the Great Australian Bight in South Australia. Maps indicate that the river begins its journey on the high ground where the Gunning Wind Farm is located. Now I understand that ridge line's topographical significance and why those wind turbines are located there. The turbines make an excellent landmark signifying the 'Great Divide' for Hume Highway travellers. It's quite astonishing to realise that this crossing point, marked on the map above, is so far inland, nearly one-third of the way to Melbourne.

As the end of my long day in the car is approaching, after I've crossed the Goulburn River at Seymour, gradually gained altitude and passed the turn-off signs for Kilmore, I reach the unmarked but geographically significant Kilmore Gap just before the Wallan South roadhouse. In summer time, as now, I am still driving in daylight.

The spot, quite close to Melbourne, is marked unobtrusively by the simple road sign shown in the photo, beside the southbound lanes of the Hume ... there's a corresponding sign as you head northwards, just past the Wallan North roadhouse. The height above sea level is unimpressive - I think it says 'Great Dividing Range, Road Level 347 m'. Drivers flashing by at 110kph, if they even notice it, might sneer at this low number and wonder why anyone would bother erecting the sign. Yet it has great significance, marking the point where the rivers stop flowing inland. Past this sign, heading southwards from the Kilmore Gap, the channels carrying our precious and scarce water resource start to flow towards Port Phillip Bay and out into Bass Strait.

In other parts of Australia, important community information of this nature is often highlighted. A sign from the Snowy area, posted by someone named Luke on doherty.net.au, is an example.

I'd love to see the tourism authorities in NSW​ and the Victoria Tourism Industry Council arrange for an informative sign at both Great Divide points along the Hume.  A short message would do - 'Great Divide, Kilmore Gap', 'Elevation xxx m', plus the two arrows with appropriate wording.  The message might say 'Rivers Flow Inland' and 'Rivers Flow to Coast' OR 'Murray Darling Basin' and 'Coastal Rivers' or something similar. Signs like these would introduce a discussion topic to help keep everyone awake on the Hume and would make the long trip more interesting​, at the same time improving everyone's understanding of this vast continent.