Mapping the Barwon Catchment

Before the arrival of John Batman and his party on the shores of Port Phillip Bay in 1835, the indigenous tribes of the Barwon catchment walked the land, following traditional "songlines" which had evolved over thousands of years. The songs and stories of the many tribes, described the land and the physical pathways they used to cross the countryside, enabling them to navigate long distances, passing safely through unfamiliar territory. I discussed songlines in my previous post.
Europeans on the other hand, saw the land very differently to the indigenous population and used very different navigation techniques. The Europeans too used maps, however they drew their maps on paper, measured distance, calculated elevations and aligned everything according to compass bearings. And they way they travelled was vastly different too. Whilst many still walked, others rode horses and drove bullock drays and it wasn't long before the paths of the songlines became the bullock tracks of the squatters. They in turn were followed by the surveyors with their chains and newfangled theodolites who marked out the roads of the selectors and villagers.
The settlers were also quick to start applying their own mapping techniques to their new surroundings. The squatter's runs were plotted out and the bullock tracks which linked them with the towns which began to pop up, were marked as vague wavy lines.

Section of Surveyor Alexander Skene's 1845 map of the Geelong District
showing early tracks and the names of squatters and early landholders
across the catchment. Original image held by the State Library of Victoria

The more the number of settlers increased however, and the more they extended the boundaries of their settled districts, the more maps were created. Not only did these maps indicate direction and location, but there were also administrative maps, electoral maps, geological maps, maps which indicated individual land ownership (an unfamiliar concept to the indigenous peoples), weather maps and many other types of maps besides. Soon the entire colony had been layered with maps and amongst the earliest of these maps were survey maps.
In order to better administer the vast areas of the new colony, the land was formally divided for the purpose of administering the sale and distribution of land. From the late 1840s until the 1890s, the government progressively undertook a comprehensive survey of the  Colony of Victoria, reclaiming the squatters' leaseholds and breaking up the thousands of acres into village allotments and farm-sized blocks. To aid administration, county boundaries were established and within each county the land was subdivided into civil parishes.

Portion of the Victorian Counties Atlas, 1874, showing those counties which fall
within the Barwon Catchment. Image taken from the State Library of Victoria

Initially, the county boundaries were by necessity ill-defined and changed according to need. The following description from the Geelong Advertiser 17th July, 1841, claiming to give the first official description of Grant County's limits, shows both how they changed over time and - like the Wathaurong whose lands it covered - how the new settlers also used the natural landscape to define boundaries.

The Coast Line from the mouth of the Werriby(sic), Port Phillip, round to a point bearing south of the sources of the Barwon [Barwon Heads]. An imaginary line from that point to the sources of the Barwon [the Otways]. the Barwon from its sources to its junction with the Native Hut Creek. The Native Hut Creek from that junction to the Buninyong and Melbourne road(sic). The line of that road to the Werriby, and The Werriby River to its mouth.

By 1871, the 37 Victorian counties as we know them today were in place. Counties and their accompanying civil parishes were - and still are - used entirely for real estate purposes, enabling the physical description of a piece of land.

Section of 1881 Victorian civil parishes map. Original image held by the
State Library of Victoria

With European settlement came the English system of government. Having been declared a separate colony from New South Wales on 1st July, 1851, Victoria needed to put a government in place, however it was not quite the system we have today. The original Victorian parliament was unicameral - having only one house. Called the Legislative Council, it was composed of 16 electoral districts from which 30 members were chosen. Ten were nominated by the Lieutenant-Governor and 20 were elected from the eligible voting population. To be eligible to vote a person had to be a male British citizen over the age of 21 who paid more than £10 per annum in rent or held the freehold for property valued at more than £100. Once again the colony was mapped and divided. This time for electoral purposes. The Wikipedia map below shows the original electoral districts and I have indicated the general area of the Barwon catchment within the black box.

Electoral districts of the original Victorian Legislative Council, 1851.
Original image from Wikipedia

Within a handful of years however, electoral boundaries were being shuffled and in 1856 a second or lower house - the Legislative Assembly - was introduced, resulting in the system we have today.
State electoral districts for both the upper and lower houses of the Victorian parliament have continued to change in response to the growing population. Today there are 88 electoral districts, each corresponding to a seat in the Legislative Assembly. These are combined into eight districts from which five Legislative Council members are elected, giving a total of 40 members in the upper house.

Current boundaries of the state electoral districts (lower house) which
cover the Barwon catchment. Original image from Wikipedia

In 1901, the cartographic landscape of the Barwon catchment changed once again with the advent of Federation. The Colony of Victoria became the State of Victoria and was divided for the purpose of voting into federal electoral divisions. These were (and still are) different to the electoral districts of the state government. The electorates of Corangamite, Ballarat and Corio are all, at least in part, within the catchment.

Federal seats within the Barwon catchment. Original image from Wikipedia

Of course, beneath the federal and state levels of government is local government. In the 19th century, local government stemmed from the need to raise funds for roads and infrastructure, consequently a series of "road districts" were gazetted across the colony. Within a few years, the road districts were transformed into shires which along with cities and boroughs today make up the various municipal districts of the local government system. Not surprisingly, as with state and federal electorates as well as county and parish boundaries, the banks of the creeks and rivers of the Barwon catchment often formed the boundaries of these early shires too. Also in keeping with other levels of government, the number of municipal districts has changed over the years. For instance, in 1915, the Shire of Meredith was amalgamated with that of Bannockburn.

Country Roads Board map, 1961 showing parish boundaries. Original image held by the
State Library of Victoria

In 1994, sweeping changes saw the amalgamation of many smaller shires and city councils in to a lesser number of much larger shires and cities. Where before the catchment contained perhaps as many as many as 15 shires and cities, after the amalgamations, this number fell to around six.
The outbreak of the Victorian gold rush in August, 1851 also saw a flurry of map making. Every digger wanted to know the best route to get to the diggings. As I have written before, there were claims, counter claims, insults and outright lies hurled back and forth between parties with vested interests in promoting their route to the diggings. Maps could not only be used to inform the general public (as below), but also to deceive as Geelong discovered when interests in Melbourne published a "false map".

The relevant section of a reasonably accurate "Digger's road guide to the gold mines of
Victoria and the country extending 210 miles around Melbourne", 1853. Image taken from
the National Library of Australia

 As well as the topography of the land and the roads and tracks which crossed it, the gold rush led to an intense interest in what lay under the surface of the soil. In 1852 Alfred Selwyn was appointed as Mineral Surveyor for the Geological Survey of Victoria and with one assistant and a tent-keeper, set about completing a comprehensive geological survey of the colony. Soil types were assessed, rock deposits dated and the potential presence of minerals noted. Over the years, the department expanded and exists today under the portfolio of the Department of Energy and Earth Resources in the Department of Economic Development, Jobs, Transport and Resources.

Adaption of the 1909 Geological Survey Map of Victoria. Image held by the
State Library of Victoria

Finally, another topic which has always been of particular interest to those living in the Barwon catchment. Rainfall. How much? How little? When? Where? Once again, the indigenous tribes had intimate knowledge of seasonal changes in climate and climate-dependent resources. The European settlers were equally as interested. They needed to know when to plant their crops and where to find water for their stock in different seasons.
Meteorological recording began in Melbourne as early as 1840 and regular, coordinated data collection began in 1854 with the establishment of the Victorian Meteorological Office. The first official report of rainfall data (I could locate) for Geelong appeared in the Victorian Government Gazette dated 21st August, 1857 for the April-June quarter of that year, although references were made elsewhere to earlier data.
Today, rainfall measurements are taken at various points across the Barwon catchment, including Weeaproinah in the Otways, near the headwaters of the Barwon River which has the highest average rainfall in the state. By contrast, the lowlands along the lower reaches of the Barwon, Leigh and Moorabool Rivers lie in the rain shadow cast by the Otway Ranges and receive a significantly lower annual rainfall.

Overview of long term rainfall averages for the Barwon catchment. Graph taken
from the Australian Bureau of Meteorology

Over the years since European settlement, many maps have been produced for many different reasons, dividing the catchment in a multitude of ways. Maps to direct. Maps to divide. Maps to quantify. Maps to persuade, even maps to deceive...

Around the bend

View of the Otways from the Great Ocean Road
near Apollo Bay

And boy did we go round some bends! After saying goodbye to this part of the Barwon for now, we headed to Apollo Bay for the night, winding our way through the Otways down to sea level. In a post not too long ago, I looked at the effect of the Otways on local weather patterns along the river. As we made it to the top of the Otways the effects of the Otway rain shadow hit us head-on.
As I mentioned in my last post, the weather was mild and overcast with an occasional shower along both branches of the river. I was a little surprised then, as we topped the rise, to be confronted by a wall of fog so thick that I could barely see 20m in front of me. The rain shadow was was suddenly very real. All that moist sea air rolling in from the west was hitting the slopes of the Otways and condensing into a thick fog whilst the relatively warm, dry air moving over the top of the ranges was keeping things mild along the Barwon. And the fog really was only at these higher altitudes. By the time we completed our descent, we had left the fog behind and the weather was once again cool and mild.

Koala at Cape Otway

The following day we were headed back into the Otways, but not before we first skirted around them and headed down to have a look at the Cape Otway Light Station which is located at the tip of Cape Otway in the National Park.
It is probably worth noting that the Cape was named for Captain Albany Otway, a friend of the English naval officer who discovered it in 1801 in his vessel the Lady Nelson.
As we wound our way once again through towering eucalypt bushland towards the Cape, we rounded a bend to find a number of stationary cars pulled mostly onto the shoulders of the rather narrow road with their occupants wandering around and in some cases, standing on the roadway.

Coastline at Cape Otway

No, it was not the scene of some horrendous traffic accident, but rather, a koala colony. Having been given the word earlier by a helpful local, we drove a little ahead and pulled into a safer clearing before joining the throngs looking up. Every second tree had its own koala, so there were plenty to go round. As English-speaking tourists we found ourselves rather in the minority here and the same was true at the light station which was our next stop.
Cape Otway is the second most southerly point on mainland Australia and was the first land sighting for incoming immigrant ships during the 19th century. The coastline along this part of the country is rather dramatic and perhaps best described as rugged, so it is easy to see why so many ships came to grief here.

Cape Otway Lighthouse

In response to a public outcry at the number of these shipwrecks in Bass Straight, the government was forced to build lighthouses at various points along the coast. Between 1847 and 1848 therefore, a lighthouse was erected at Cape Otway and then, in 1859 a telegraph station was added to service a subterranian cable running between Tasmania and the mainland. However, the cable foundered after only 6 months and the telegraph station became a signalling station which passed shipping news to Melbourne.

Cape Otway Telegraph Station

Today, the restored building houses a museum whilst the lighthouse - which still serves its original purpose - is also open to visitors. We viewed the museum, climbed the 78 steps of the lighthouse, learnt a little of the indiginous heritage of the area and also took a look at 40 recently acquired paintings of ships significant to the history of Australia.
And then, having seen what there was to see, we departed, heading upwards once again into the mountains for a walk amongst the treetops.

Whether the weather

Every time I run round the river when it is windy, I could swear that I seem to be running into a head wind, no matter what direction I am running. This perception probably isn't helped by the fact that I often start my run in a westerly direction and the prevailing wind around here is yes, westerly.

Rain storm moving across Geelong, viewed from Tait's Point

Yesterday was no different. I hit the river at Landy Field and headed upriver, beating into a solid westerly. By the time I was on my way back, I could swear I was still running into the same head wind and not for the first time, it occurred to me to wonder what impact the weather has on the river and - conversely - what effect the river and its surrounding geographical features might have on the weather.
In previous blog posts I've mentioned the impact of day to day wind patterns on the wildlife which lives along it banks - fish and birds seem quite sensitive to wind levels. In geological terms, wind caused the build up of sand dunes at the mouth of the Barwon, helping to shape the estuary as we see it today.
However, the most obvious element of the weather to affect any river is rain - its lack or abundance determining water levels along the length of the watercourse. The Barwon River is no different in this respect, with the river and its associated ecosystem relying on regular flood cycles to maintain a healthy balance along its length.

Barwon at Geelong in flood, 16th January, 2011

Not surprisingly, rainfall levels vary from the headwaters in the Otways to the river mouth at Barwon Heads. Through Geelong, the average annual rainfall is 552.7mm, however the main ridge of the Otway Ranges averages almost four times this amount at 2000mm per annum. This occurs as a result of what is called a rain shadow which is caused by the Otways themselves. In short, warm, moist air flowing in from the west hits the mountains and is forced upwards, cooling and condensing as it rises. Any remaining cool, dry air flows over the mountains and descends to the plains below which are sheltered from the rain on the other side of the range. The rain shadow cast by the Otways extends as far as Geelong and Werribee, making this the driest area in the state, with an average rainfall only about 55mm higher than - for example - Barcaldine in outback Queensland and 16mm lower than Roma.
Little wonder then that, most of Geelong's water supply comes from catchments in the Otways, namely the West Barwon Dam which also plays a significant role in mitigating the effects of flooding on the lower reaches of the Barwon. It does not however, prevent it entirely as we saw earlier this year when moderate flooding was recorded.

Baum's Weir in flood, 16th January, 2011

Flooding occurs through Geelong after about 150mm of rain on a dry catchment or 75mm on a wet catchment over a 1-3 day period. Typical weather patterns which produce this kind of rainfall are either a slow moving low pressure system over Victoria and southern New south Wales, a low pressure trough moving down from the northern states - such as in the case of a cyclone as occurred in January - or persistent winter rainfall.

The three highest flood levels recorded through Geelong were in 1880 (4.59m), 1952 (5.47) and 1995 (5.23m). By comparison, the flood this January (reaching around 4m through Geelong) was not outstanding. Despite this, there was still quite a mess to be cleaned up and it is easy to see the impact the the force of a flooded river can have on the landscape.
Another factor which has a significant impact on river health is temperature, which along with rainfall can affect water levels through increased water storage use and through evaporation. This, along with issues of pollution can lead to increased salinity in the river system which in turn puts stress on the plants and animals which rely on the river. Likewise, a change in the water temperature of the river in combination with low water levels and high nutrient content can - and in summer often does - lead to an outbreak of blue-green algae. This is toxic to humans and animals, causing skin irritation, nausea and asthma/allergy symptoms.

Of course,wind is also an important aspect of weather conditions, however, I must say that despite a significant on-line search, I can find little information about wind patterns and the Barwon, unless it is to discuss short-term forecasts. I would imagine that at the very least, the shadow of the Otways would provide protection from wind for some surrounding areas or that at some points, the natural geography of the river would influence local wind movements. But I can find no on-line mention of such effects.

Queen's Park from Windmill Reserve

One final weather phenomenon which I have experienced around the river but so far had not until now photographed - although others have - is fog. The fog which forms in river valleys is generally of the type called radiation fog. It forms at night in clear weather with little wind. After the sun sets, radiant heat is lost from the Earth's surface and forms a layer of moist air close to ground level. Humidity rises and fog is formed. This fog can be quite dense and can hang around for quite some time. I live on higher ground above the river, so I can sometimes leave home on a bright, sunny morning, descend into the river valley and find myself in another world filled with damp, cool air. This was the case during a trip to Fyansford earlier in the year when it took a good several hours for the fog to clear to reveal the sun which I knew was just overhead.
I imagine that the natural depth of the river valley, the moist environment and the slightly cooler temperature closer to the water all play a part in preventing the dissipation of fog which occurs on higher ground - another example of the river influencing local weather patterns.