A visit to the Big Lake

Today's expedition took us not to the Barwon, but to the place where much of its water is stored - Wurdee Boluc Reservoir (sometimes also spelt Wurdiboluc). This is, I am informed, an Aboriginal (I assume Wathaurong) name meaning "Big Lake". Which is quite appropriate.

Wurdee Boluc Reservoir

For those who haven't been there, the reservoir is located a short distance to the South West of Winchelsea and can be accessed via Cape Otway Road. Water from the Barwon however, takes a somewhat different route in its approach to the reservoir.
From the West Barwon River, Munday Creek and the surrounding catchment areas, water is collected in the West Barwon Dam (capacity 21,504ML) in the Otways as mentioned in previous posts. But where does the water go from there?
Well, initially, it flows downstream a couple of hundred metres at which point water is taken via the West Barwon diversion pipe to the East Barwon diversion weir which also collects water from the East Barwon River. From the weir, water from both rivers is carried via the Wurdee Boluc Inlet Channel, collecting further flows from several creeks on the way. The channel then makes its way to the Wurdee Boluc Reservoir where up to 38,056ML of water can be stored at one time.

Wurdee Boluc Inlet Channel

The reservoir also receives water from the Barwon Downs and the Anglesea borefields. Once in the reservoir, water is then treated before transfer to Geelong and surrounds for use in the domestic water supply.

A view across the reservoir

According to the information board on site, the reservoir (known as an "off-stream storage" facility) was built in 1929. It was further enlarged to cope with increasing demand in 1955 and then again in 1991 to its current capacity. The embankment which surrounds the reservoir is 8.7km in length and the surface area of the whole is some 564 hectares. At its deepest points, it reaches 12m. In total, this system supplies around 70% of Geelong's water requirements.

Wurdee Boluc Reservoir

In addition to providing water to the populace, the reservoir is a popular fishing spot with the locals as well as being home to a healthy-looking population of water birds and a startlingly large number of kangaroos which we were able to see as we walked along the embankment after lunch.

Kangaroos at Wurdee Boluc Reservoir

Kangaroos at the reservoir

First however, we ate our picnic at the Vines Reserve which has a public parking area and picnic tables just off Cape Otway Road and provides public access to the weir.
The reserve - as the board informed - is named for Dr G.J. Geoffrey Vines who joined the Geelong Waterworks and Sewage Trust in 1965 as Senior Design Engineer. Throughout his career and until his eventual retirement as CEO of Barwon Water on 17th June, 1994 - a position he held from 1984. Dr Vines oversaw the development of many major improvements in Geelong's water and sewerage supplies. These included the sewer outfall at Black Rock, the planning and instalment of sewage to several of Geelong's suburbs, the development of the Barwon Downs borefield and the upgrade of the Wurdee Boluc Reservoir and development of its water treatment plant.





A clear winter's afternoon at Wurdee Boluc Reservoir

So, with our knowledge of Geelong's water supply further increased and the sun beginning to drop towards the horizon, we completed our stroll, left the fishermen to their rods and headed for home.

Doing the cycad stomp

On Monday I packed the kids off to school and headed for the hills - literally. I decided I needed a few extra photos for my annual Barwon calendar, but they just happened to be on parts of the river which were about as far away as I could get. Despite this, I decided I had time to make it there and back and get the shots I needed.

West Barwon Dam, confluence of the West Barwon River
and Munday Creek

I made good time and snapped snapped away at the West Barwon Dam which was looking suitably vast on this sunny morning then headed for the east branch of the Barwon. Here I made a quick circuit of the lake, took more shots - including the one I needed for the calendar - and stopped for a break.
As I was sitting at a high point overlooking the lake, I read the strategically placed, but rapidly fading, information board. It informed me - as I knew - that early in its existence, the level of the lake was lowered by several metres after the upper part of the landslide which had originally dammed the river, gave way.
What happened next is still visible today.
Not surprisingly, the trees and other vegetation which had been submerged by the initial inundation had died off. When the water level fell after the partial collapse of the initial landslip, several metres of deforested bank was revealed. This provided an opportunity.

North bank of Lake Elizabeth (left) showing regrowth of land originally
covered by higher water levels

On the cool, shady north bank of the lake, the cycads took hold - the green fronds of tree ferns which were ideally suited to this environment came to dominate the land immediately above the water level. The myrtle beech trees, so common in other parts of the temperate rainforest found in the Otways, also took their opportunity.  From where I was sitting, a quick glance showed this quite clearly to be the case.

Amongst the myrtle beech and tree ferns on the north bank of Lake Elizabeth

On the opposite, more exposed bank I was informed, tussock grass found a niche and established itself.

Lake Elizabeth Beach from the north bank

Tussock grasses on Lake Elizabeth Beach

Looking at this bank from the opposite side, the definition does not seem to be as clear as on the north bank, however it is certainly different, more open and with less of a rainforest feel to it.
So, armed with the necessary photos and some new information, I completed my circuit and headed once again for the lower reaches of the Barwon.

A tale of two rivers

At the end of the previous post, we had stopped for a picnic lunch at the bridge across the west branch of the Barwon at Kaanglang Road outside of Forrest - a pretty spot with large trees rising all around.Next, we headed off, up a walking track which took us along the east side of the river towards the wall of the West Barwon Dam.

The terrain was relatively flat and the walk an easy one. The river at this point is still little more than a trickle, despite the presence of such a large reservoir so close by. This I discovered is the result of a controlled flow released from the dam by the relevant authority -  Barwon Water. What is not explained is how they decide exactly how much water is to be released from the dam at any given point in time and what impact that has on the river further downstream. For that matter, it would be interesting to know what type of river the Barwon would be if there were no dams, no weirs and no Breakwater to control the flows along its course. The Wautharong would have known.

Old apple tree run wild

The scenery along the track is a combination of towering gums to either side, a variety of non-native deciduous trees beginning to show the effects of autumn, clipped park lands and - somewhat incongruously - old apple trees which presumably are the remnants of another era. Regardless of their origins, the apples seem quite at home in their surrounds and are currently fruiting prolifically, cascades of fruit hanging from branches several metres high.
At one point, there appears to be a small weir which restricts the flow of the river and at another, so the visitor information at the dam informs me, is a pipe which feeds water from the West Barwon branch of the river across to the east branch. And so we continued, following the track, but - due to a noticeable lack of signage - not exactly sure where or how far we were going.
Despite this, we found ourselves after not too long at the foot of the dam wall and wondering how to ascend. Immediately in front of us was a wide spillway, obviously designed to carry overflow if the dam exceeds its capacity, however judging from the amount of graffiti to be found up its length, there has been no danger of an overflow in quite some time. To our right was a small foot bridge and a path which, we eventually discovered, would take us to the top of the wall. Another vestige of earlier times took the form of blackberry bushes growing to either side of the path, their fruit almost finished.

View of Munday Creek and West Barwon from the dam wall

The view from the top was, as you might expect, panoramic. The wall is located just below the junction of the west branch of the Barwon River and Munday Creek which flows into the Barwon from the East.

Walking across the top of the wall, we were able to see a short distance up each waterway, both of which appeared to be heavily wooded. It is pleasing to know that logging in the area has finally stopped, giving our most important waterway a chance of survival.

As is to be expected with such a large man made structure, tourist information concerning the history of the area and the dam itself was readily available. From the board I learnt that the dam was built in 1965 by the then Geelong Waterworks and Sewerage Trust (now Barwon Water) and now provides the majority of the water supply for the greater Geelong region.

Whilst boats are banned and swimming or wading is not allowed in the dam, fishing (with a license) is allowed from the bank. The dam is stocked with the expected supplies of eels, both brown and rainbow trout, redfin, and blackfish but other than at the dam wall, access can be difficult from the bank due to the steep approaches and thick tree cover.

Barwon East Branch

Perhaps more excitingly, the dam is also home to a small population of platypus, although I can not say we were lucky enough to spot one while we were there. After reading the boards and checking out the view, we headed back down, this time, taking the path down the opposite bank back to the car.

At this point, we still had a little time to spare, so we decided to head up a little higher and investigate the east branch of the Barwon.

What a difference a few mountains can make! The East Barwon I discover, is quite different from the West. Whereas the latter has been somewhat altered from its native state by exotic plantings, obvious signs of European influence and not to mention the dam, the east branch by contrast, is another world. It is cool, damp and has a distinct rain forest feel to it. Whilst the trunks of soaring gum trees rise above both rivers, along the banks of the east branch, the under plantings are much closer to the water and tree ferns are abundant. There are no clipped park lands, but rather a simple dirt track which winds its way beside the river, rising higher into the Otways as the track makes its way towards Lake Elizabeth.

Billabong beside Barwon East Branch

By the time we arrived at the bottom of the track, we were limited for time. So after another quick cuppa to sustain us, we headed upwards. At one point we came upon a pool - a billabong.

Really running short of time at this point, we continued up the trail, hoping to make it to the bottom Lake Elizabeth which we knew was somewhere up ahead.
Once again, we'd studied up on our tourist information and had been informed that Lake Elizabeth was formed on 17th June, 1952 when a landslide blocked the east branch of the river, forming a natural dam wall. The landslide was not discovered until a party was sent to investigate the sudden cessation of the river's flow. A little under two months after the landslide, the dam overflowed running down a natural channel. A year later in August 1953, the top 26 metres of the dam wall was washed away after particularly heavy rains, reducing the lake to approximately one fifth of its original volume, and changing the course of the river. The resulting watercourse was straighter than the original and lined with boulders and gravel along its length, carried down by the second landslip.
As we walked, the track continued to rise, steeply in places, until it was many metres above the height of the riverbed. Despite this, the gums growing at water level still towered above us. Eventually, with the light continuing to fail, an executive decision was made that we should walk until 5pm and if we had not reached the bottom of the lake by that time, then we would turn back.
Disappointingly, this did turn out to be the case. Whilst the walk was only a couple of kilometers, we were out of time. Lake Elizabeth and the promise of some fairly spectacular photographic opportunities would have to wait for another day. So we turned back and headed down to the car park, which somewhat surprisingly was busier than when we first arrived. Then, after a quick stop to use the visitor facilities, we were on our way home.