Tis the Season

To be jolly etc etc.  Also the cyclone season.  Though perhaps a bit early this year.  Cyclone Jasper came with plenty of warning and just managed to crank up to a catogory 2 as it crossed the coast at Wujal Wujal a comfortable 200 km north of Possum Valley.  So only gale force winds experienced here.  So I only had to get out with chain saws and clear the track of about 4 blockages.  A mere half day of hard labour.  One of those managed to anticipate the cyclone and collapse the day before.  OK, I thought.  All over and the cyclone remnants, a tropical low makes it’s way to the gulf maybe to evaporate or maybe to re-intensify as it gets over the power-house of warm water in the shallow gulf.  Seen it before, all done and dusted.  That’s what BOM thought too, but just to confound us, it lingered.  And lingered.  I got 5 days of heavy rain to total 753 mm, some places down the coast got 2000 mm.  Many, many cities are built on flood plains, consuming the best agricultural land and no doubt before many a crop has been wiped out by flooding but can be replanted when the floods recede.  Now houses have terrible damage and cities may be wrecked by intense weather events exacerbated by climate change.  Take to the hills people.  To less food productive areas but founded on rock and far from floods.  Then centuries later, when concrete has crumbled to gravel, it may be possible to use the flood plains for their best use as productive areas for agriculture.

So Possum Valley was spared the heaviest rain, but I have infra-structure in the creek to provide power and to pump water.  I went on a tour of inspection which just revealed that hydro and pump were invisible under torrents of brown foaming water with the occasional bit of pipe showing shuddering and shaking as it was knocked around by the flood waters.  The hydro generator was under water which is a bit of a worry as it is generally recommended that electrical devices don’t get totally immersed in pounding dirty water for a couple of days.  You can find this advice in many service manuals.  Then the rain suddenly stopped and being at the top of the catchment area, the creek went down very quickly.  So it was now time to get to work and restore power and water.

During the days the hydro was out of action, I had patched in a petrol generator so PV was not without power.  I also have some solar panels, but the cloud layer was so heavy they provided next to no power.  It was dim and dark even in the middle of the day.  So when the flood had mostly subsided and I could stand in the creek without being washed away to Innisfail, I went to the weir at the top of the turbine penstock (down pipe) and it was totally filled up with gravel.  So I shoveled it all out and knew that a lot of gravel and debris must have gone down the pipe.  Down to the bottom of the waterfall where my first job was to find the turbine and generator.  I knew where it was bolted to the rocks and concrete, but it was buried under a mass of logs, sticks, roots and vines that had been interwoven by the tumbling torrent.  I thought I might have to get a chain saw, but I managed to get them out heaving one end at a time.  This is working in the creek wrestling wet logs so I am totally sodden and muddy in a few minutes.  OK, after half an hour I have uncovered the turbine/generator, but the bottom part of the pipe is totally jammed with gravel so it wont drain out of the nozzle.  I have plugged the down pipe (penstock) at the top, but I can’t move it to disconnect until I get the water out.  On the last pipe connection is a 25 mm plug so I take that out fully aware that water will come blasting out under 20 m of head.  For the last few turns of the thread I keep my hand on top of the plug or it will be blown away into the sky never to be seen again.  Wham! there she blows, and in half a second I am blasted with muddy water.  I go from sodden to drenched.  I wait for the water in the pipe to drain, but it doesn’t and just keeps coming???  The only answer is the pipe plug I put in the top has failed.  So I have to make a new one.  To fit the 125 mm pipe I plug it with 2 plastic flower pots which are nicely tapered to make a good seal.  Being flower pots they have drain holes in the bottom so I put a stout couple of plastic bags between the two jammed together.  So with a new plug to stop the flow, I can move and disassemble the last section of pipe and the nozzle.  Back to the bottom and I can now lift out the last section of pipe and undo the last connection.  I dump out a wheelbarrow-full of rocks and debris, wash out in the creek, change the nozzle to a bigger size as I expect there to be plenty of water and more power for the next nine months or so.  I reassemble and start it up wondering if the generator will work after being underwater for a couple of days.  No worries, off she goes.  I can easily tell it is producing power even though there are no gauges down at the bottom.  If no power there is no load on the turbine and it goes twice the speed producing a thundering roar as hits the back of the casing.  Taking the power out of the water with the turbine makes it just hum and hiss is a pleasing way.  I have already put a larger dummy load on in anticipation of the higher power.  Back in the power generation business!

That took about 6 hours of hard yakka, shoveling, heaving logs, up and down the waterfall I emerge pleased but looking like “the creature from the black lagoon”.  After ancient 4th rate horror film.  Except I have a cheerful bright colour contribution.  Red legs.  The leeches have been waiting all year for this combination of very wet and a lingering target.  There was no chance of protecting myself with repellent spray, which works very well, as it would all be washed off in 30 seconds.  So I finish the job before dealing with them.  First dry hands as they are difficult to remove with wet fingers.  It took me perhaps 15 mins to remove 50-70 leeches.  These I discard into a little pot with some laundry detergent.  Leeches are an ancient order of hundreds of species and most of them don’t suck blood, but they don’t have a waterproof skin and and strong chemicals dehydrate them very quickly by osmosis.  During this time a prospective guest phoned up to request a booking.  I asked him to phone back in 10, as I had a heap of leeches to pick off.  Probably the best call dump he has ever heard and I was surprised when he called back and made a booking.

My next task was to restore the water pump, last glimpsed with the pipes heaving about in a raging torrent.  I got down there and found everything in place and thought ‘this won’t take long’.  Foolish optimism.  As expected the weir to divert some flow to the pump header tank was destroyed and vanished, but amazingly, the pipe from the weir to the header tank was still there even though a flimsy and cheap piece of plastic gutter pipe.  But with the weir gone there wasn’t enough water going down the pipe to run the pump.  I didn’t want to build a new weir as this is just the beginning of the ‘wet’, so I thought I would just back up the water a bit to cover the pipe inlet and get the flow.  30 m upstream were a couple of big rocks.  Too big to lift and carry but I can roll them down the creek and when they are submerged a good part of their weight is negated.  More grunting and heaving, more floundering about in the creek.  But it does the job of getting more water into the header tank.  Then the pump, with only 2 moving parts jams up.  Clapper valve back to the workshop for some careful filing of the valve guide.  OK, not sticking now, but stalls.  Oh! the discharge pipe ripped in two by the torrent but underwater so I can’t see it.  Fix that.  Then the header tank (old bar fridge laid on it’s back) leaking so much there is not enough water for the pump.  Find new(er) bar fridge from my white goods graveyard in old shed.  Rip out compressor, rip off door and shelves, make 75 mm hole in the bottom and good to go.  Pump still doesn’t go.  Goes for a few cycles (about the speed of a heartbeat)  but then gets a double beat and even a triple beat before stopping.  I am homing in on the problem.  It is air getting into the ‘driver pipe’.  The  75 mm steel pipe must have a hole in it which lets air into the pipe.  I crawl up and down the length of the pipe but cannot find the leak.  Water runs everywhere and splashes up from the creek and down the pipe so no chance of just looking for a wet spot.  I eventually found the leak at one of the threaded connections.  It takes an heavy duty clamp with a extra thick gasket, a strip of a stubby cooler, to seal it.

My commiserations to the people flooded down the coast where some houses were a complete wreck, and many more flooded causing many thousands of $ damage.  They are now negotiating with insurers and it may be months before order is restored.  I could fix my stuff in a few days hard labour and at no cost.

I had my eldest daughter’s family here for Xmas dinner and it was excellent with good food and relaxed fun.