Tag Archives: Tarraleah Canal No 1

Between Wayatinah and Catagunya Power Stations- posting 5 of 6

 

Above the complex of Catagunya Lake, Dam and Power Station there were a number of viewing points from which to study the construction of the dam, the head race, switch yard, etc. It was so easy to admire the engineering feat that established this enterprise. Water was not moving in the race so it seemed that the Catagunya Power Station was closed down.  Maintenance? Too much power being generated elsewhere? Water conservation and therefore prudent power generation management practices?  The reason is unknown.

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Did you notice how thin the water race walls were?  If you imagine the pressure of the water in the race you might believe the walls should be thicker. Certainly, when compared to those of Tarraleah Canal No 1 (refer to photos in my earlier postings) these walls are much slimmer, and they do not have cross beams linking both sides together.

Did you notice the ladder over the wall?  On this side and a second on the other side?  This is more than is on offer in Tarraleah Canal No 1.  Of course the ladders would be used as part of maintenance programs when the race is empty, and only a fool would step over the edge while the race is full of water. Since the power generation could be restarted at any moment, the speed of the water flow would almost immediately turn anything in that water into an electrical spark.

When looking at the Dam wall, Andrew saw specks of movement; these were the only people encountered in the whole day – three workers doing some work on the curving face of dam’s spillway. Can you spot them in the photograph?  They are working on the yellow curved frame which has been custom built to move from left to right across the curve of the dam wall.

Andrew remarked, “I could hear their voices echoing off the concrete walls, but they were far too distant for them to see me”. There was no-one at the Power Station itself – so Andrew passed by with no-one the wiser that the visit had occurred.   One sign attracted his attention.

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It was quite extraordinary to see a sign with an image of a dolphin so far inland. Hydro Tasmania must be congratulated for alerting others to the damage which can be done to marine life should people pollute Lake Catagunya/the Derwent River.   Apart from the damage to sea life 60% of Hobart’s drinking water comes from the Derwent River so the protection of these waterways is of paramount importance.

Revisiting Butlers Gorge for missing photos – posting 1 of 5

After I walked from the Lyell Highway at the Butlers Gorge junction and then proceeded to follow Tarraleah Canal No 1 (which contained the bulk of Derwent River water) to Clark Dam holding back the waters of Lake King William, I returned home and checked my photos.  I found some key photos were absent.

I realised that my feet must have been exceptionally painful and my sore knees crumbling so that I was unable to remember to keep taking photos in that last kilometre of the walk.  I had made no record of those last few hundred metres.  Thanks to blog reader Jeanette I returned to the spot one gorgeous morning, walked up and down the area and clicked lots of photos.

At one place we crossed the aqueduct and looked at the serene and clear Derwent River.   20160425_112018.jpg

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The rush of the water through the Canal was recorded.  Watch this video.

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I loved the views looking along the two strands of the river; the water in the original river bed, and the water in Tarraleah Canal No 1.

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The rocky edges of the river shown above indicate that water is released from Clark Dam from time to time making the river wider.

From the visualisation to the actual – towards Wayatinah post 2 of 9

The question remained. Was walking this leg achievable? Was the Derwent River sufficiently friendly to allow humans to walk its length? With my feet and knees complaining every time I walk for more than a couple of hours, I asked friend Andrew to proxy for me and undertake the walk along the Derwent River from near Tarraleah to Wayatinah. Since Andrew is a fit, agile, very experienced and sensible bushwalker, I felt certain if he could not finish this leg of the walk then no-one could. Besides he has been a positive supporter of the project from day one and was happy to undertake the walk on my behalf.

At 6.30 am, the day started with a drive from Hobart to the bridge crossing the Derwent River at Wayatinah. After parking his ute on the Florentine Road near the salmon hatchery at Wayatinah around 8.30 am, a friend drove him westwards along the Lyell Highway to the junction with Butlers Gorge Road. Under overcast skies on a cool day, Andrew began walking next to Tarraleah Canal No 1 around 9.30 am and continued until he reached the first crossover walkway about one kilometre further on. This location promised the shortest distance down to the Derwent river bed.

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Andrew crossed, looked downhill and saw nothing but dense scrub ahead. He remembers remarking out loud “don’t dither, just do it. Don’t delay.  Here we go; just do it”.  At 10.10 am he left the Canal. Before stepping into the unknown, he spent time getting a GPS position fix and a magnetic bearing. Once set, he plunged into the thicket and took a series of sightings from one key tree to the next.  This allowed him to stay on his bearing, and meant he would be able to retrace his steps if the going was too tough and the forest impossibly dense.  The route down the steep slope passed massive tree ferns, smaller ferns, myrtles, mature eucalypts and the occasional Sassafras tree.  Many fallen trees littered the understorey and it was clear this was an old forest in a constant state of regeneration. Scrambling over or under logs and negotiating rocky bluffs was a normal part of the descent.

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Half way down the steep incline,  it seemed that serious wind was blowing high up in the trees. Before long it was clear the rushing sound was the water of the Derwent River further below.  Once the river could be seen, then it was a comparatively simple process to choose the clearest path to the river bed.

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Visualising each walk in advance – towards Wayatinah post 1 of 9

The further I travelled inland towards central Tasmania, the less guidance and direction was available. This meant that I needed to scrutinise every piece of available information more intensely because the challenges of the terrain increased and therefore the dangers of walking alone multiplied.  My friends and relatives feared the worst and hoped for the best and we have all been thankful that my walks and returns home have been safe. Apart from the occasional bruise and scratch or two, no physical harm has befallen me.

During my first walks along the Derwent River, I gradually increased the volume of research I conducted in advance, so that I could make the most of each opportunity.  As the project lengthened, I spent more time visualising the walks so that I could be sure my pack contained the appropriate provisions. In addition, I wanted to be sure that I could achieve my goal.

In particular, I invested a huge amount of time imagining a couple of the walks. These were walks about which I knew very little and which I anticipated would be the trickiest.  One was the walk along the river starting near the junction of the Lyell Highway and Butlers Gorge Road close to Tarraleah, and extending to the bridge over the river at Wayatinah.

Using knowledge from my walk along Tarraleah Canal No 1 and from walking beside the Derwent River near the Wayatinah bridge,  I had some understanding of the challenges. My intention was always to start at the Tarraleah end and work my way downstream along the River bed.

The first obstacle was the dense bush between the Canal and the river bed down an exceptionally steep incline. From what I could see at the top, the rainforest was a tightly packed mangle of massive tree ferns with their fronds at face level and above, amidst all manner of eucalypts, myrtles,  celery-top-pines, sassafras trees and laurels.  If I was very unlucky intermingled with these wonderful but tightly packed specimens, I suspected the tree known as Horizontal (Anodopetalum biglandulous), the anathema to bushwalkers, could be a major impediment.

Photos near my imagined starting point show the beautiful but almost impenetrable bush facing the start of my walk along this section.

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I believed I had two options; one was to walk along the plush mossy flat Canal verge until I could spot a ‘gap’ and then plunge into the thicket.  The second option was to walk on the track beside the Canal until I reached the first Hydro Tasmania crossing located about a kilometre westwards along the track,  cross over, and hope there was some sort of clearing through the bush down to the bottom of the hill.  If not, then I would have to make my own way until I reached the Derwent River bed.   The first crossing, in the photo below, shows no sign of tracks extending further.

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From that crossing down to the river, I anticipated the distance would be approximately  one and a quarter kilometres on a slope that dropped around 210 metres.  Unless I was fortunate to find a clearing that Hydro Tasmania had made, something like the following example spotted closer to Clark Dam, I expected to be in for a hard time.

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I knew this was the side of the river that received minimal direct daily sunlight compared to the bush on the other side. I imagined a wet slippery bush environment, that would be dark amidst the undergrowth ( I am short and I realised much of the vegetation would be above me) with interspersed and unpredictable rocky outcrops that would require flexibility and care. If the day was overcast, my ability to see clearly through the dense bush might be limited, so the danger of slipping over a cliff had to be taken into account.

While Michelle’s photo below taken during a flight along the Derwent River shows the vegetation between the Canal and the River bed, the location is further along towards Clark Dam. Nevertheless it does show the density of the bush which needed to be penetrated and walked through.

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My aerial photo below gives a stronger sense of the gradient from the Canal to the river bed in some sections.

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The photo below, which I took during my Canal walk, looks back and clearly shows the steep gradient.

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I imagined slipping and sliding part way, with backpack occasionally getting ‘hooked’ to slow me down. Despite the short distance but considering the possible obstructions and the need to skirt around these,  I mentally allowed at least an hour for the descent.

On the River bed I hoped for a low water level in order to be able to rock hop for much of the 14-15 kilometres down to the Wayatinah bridge. If the water level was low, at best the river bed might look like the following photos as it did near the confluence of the Derwent with the Florentine  Rivers.

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Alternatively it might have limited water something like the following photos of the Derwent near Wayatinah.

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Of course, hoping for minimal water was likely to be a pipe dream and I realised it would not be realistic to expect this situation for the entire length of the walk. I knew from aerial shots, old maps and out of date Google Earth that large pools of water would present challenges and that clambering up any side of the River to avoid these would be part of the walk.

From maps I could see approximately  eleven small creeks and the Counsel River feed into the Derwent. I fervently hoped little rain had fallen in this area in the preceding weeks, that these creeks were low on water, and therefore that the spill into the Derwent River would be minimal. If much water ran down these creeks then the likelihood of more and larger water holes along the Derwent increased. If this was the case then I could imagine fighting my way through vegetation overhangs in order to clamber onto the bank and then negotiate the forest to bypass the water obstruction.  Anticipation of such exhausting activities did not thrill me.

Once on the River bed, rocks that roll were at the top of my list of fears; such as – would I turn an ankle, break a leg, smash my head into another rock, or get weighted down in a deeper pool with the pack on my back.  I could not see how developing any sort of walking rhythm would be possible. My usual opportunities to walk and look around me would be unlikely. I foresaw the absolute necessity to watch the ground/rocks/water and think about and make decisions where to put each footstep would become mentally exhausting over such a distance.  I doubted if it was possible to walk this stretch of the River and, even if it was, I thought the possibility of covering the length in a day even a long day, would be unlikely.  I allowed two days for this leg of the walk.

I always take my tablet for photos and carry this with me to point and click as a record. Typically on a one-day walk I might take 300-400 photos and then pick a selection for the blog posts.  But for this walk I realised that carrying the tablet would not be wise. I could see that having two free hands to clamber over rocks and debris and vegetation would be smart, and I also needed to allow for the unexpected underfoot changes and the need to grab or balance using my hands.  Clearly stopping to retrieve my tablet for photo ops would slow me down. Therefore, I knew that I would not be taking many photos so that the record of this walk would be less than normal.  But my safety had to be paramount.

From aerial reconnaissance and nearby on-the-ground checks and maps, I found it difficult to visualise where I would set up the tent overnight.  Both hill sides were steep but maps did indicate that near some major bends in the river there was sections beside the water bed that might be a little flatter than elsewhere.  On one bend, some larger islands were mapped mid-stream. I wondered whether I might be lucky to find them water free and accessible and not totally tight with vegetation.  Perhaps there I might find a sleeping spot.

Overall I visualised a most unusual journey. One where the only view would be of steep forested hillsides rising above a comparatively tiny water bed, and never a panoramic vista of distant hills or mountains. Rather I could expect to see only the next bend in the river. While that would provide me with curiosity about what might be around the corner, in advance, already I imagined seeing more of the same.  So this leg of the journey along the Derwent River was to be about physical endurance; surviving without becoming despondent about the relentlessness of watching my feet placement.  This was the ultimate chance for me to understand the limits of my capacity and capabilities.  I looked forward to  snatching and enjoying occasional moments when native birds flitted about, the sun sparkled on wet vegetation, and variations of mosses and lichens on rocks appeared in all their glories.

I envisaged this experience would introduce me to a continuous valley that is currently protected, untouched, unvisited, and not normally seen at close quarters.  Simply wonderful, however great the challenge to see it.

Tarraleah Canal No 1 walk – forests and fragrance

Before I had walked more than a few metres, I was delighted to see the multi species rainforest growing densely along the edge of Tarraleah Canal Number 1 and by the side of the Hydro Tasmania vehicular track next to the Canal.  The air was clean so that every hue of green, grey and brown provided a clear and rich visual texture.  The environment uplifted my spirits.

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All day I revelled in the fragrance emanating from the forest.  It was one of my walk’s great highlights. Thankfully my nostrils did not sniff out rotting animal odours.  From midday into the early afternoon when the air was warmest, the natural oils of the trees dispersed creating a strong natural perfume.  I could not identify all the trees that were visible leave alone those that were hidden in the dark thickets.  Therefore, I could not identify what I smelt.  I tried to think of words to describe the smell, but every description I considered is woefully inadequate. All I can say is that there was a hint of eucalyptus but a stronger minty-like freshness floating and pervading the environment.  I would love to be able to bottle that forest fragrance.

The quantity and volume of tree ferns astonished me as did how close they grew to each other. I guess that the disturbance to the ancient original forest, which occurred when the Canal was built, caused a monoculture of these plants to thrive.  Another of my walks, the one between Wayatinah and here, passed through this ridiculously dense bush. Often there wasn’t a person-sized space between the tree ferns, but I will write more about that challenging walk in a future post.

 

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This hilly landscape with the old Derwent River bed at the bottom constantly surprised me. I could see that thick seemingly impenetrable forests grew either side of the river bed.  In the photo below, the land drops steeply to the river bed and then rises equally steeply on the other side.  For much of the length of the Canal, when I looked at 150 metres of land across the flatness of a map, I realised the Canal was 250metres above the river bed; both the length and the steepness of the drop seemed extraordinary to me.

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Towards the conclusion of the walk the nature of the vegetation seemed to change from dense wet thicket to a dryer and slightly more open landscape – or was it my imagination.

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