53 Dam

The bad thing about the Glockemann pump was that when I didn’t irrigate, the header tank overflowed, admittedly slowly. Either I could turn off the pump when the tank was full, a sensible solution, or increase the farm’s water storage. I opted for the silly route. I would make a small dam right by the tank to take any overflow. This would also be an excuse to use the tractor that had been sitting idle with flat tyres for 2 years.

Within an hour of starting it up, following half a day of pumping air, refuelling, greasing, and removing birds’ nests from the cabin and debris leaning against the sides, the tractor had made a dam. I ran the tank’s 8000 gallons of water into the dam to test it. It looked great in mind space reflecting images of wading birds, frogs burping and tadpoles swimming, a jungle of native plants fringing its edges and of course a few floating lily pads iridescent with dragon and damsel flies.

The following day it was empty. The porous gravelly soil was no good. I either had to spend a small fortune on sealing it with clay, estimated cost $500, or lining it with plastic and rubberised sheet, estimated cost $500. I opted for a much cheaper wheat silo-lining plastic sheet with poor UV properties and easily holed by animals like sheep and kangaroos, estimated cost $200. I would use old carpet from the tip held down by rocks to cover the edges of the silo plastic thus avoiding UV and physical damage. These solutions worked well. The overflow from the header tank splashing into around 12,000 gallons of water from a height of 2 metres complemented the scene. Within three years the mind dream became reality.

51 Not so free irrigation

It was hotter that summer and the raspberries needed gravity dripping twice a week. A 24-hour drip used 2500 gallons of water. If we also did the chestnuts the 8000 gallon header tank was emptied in one go. Our method for filling the tank at first copied Torsten. It was to carry a petrol-driven fire pump down to the river, join it to our 2” mains feed that ran up the centre of the farm, prime it and pump for about 5 hours. Then the pump was disengaged and carried back to the shed. It was a drag carrying it back and forth and she pretended she couldn’t lift it, so I upgraded to an electric pump with a powerful suction that I could site above flood level.

This had to be a temporary measure because I didn’t like paying the electricity bill. I looked for a green and constantly-running-cost-free alternative. It appeared at a local agricultural show we visited accidently. The Glockemann was brilliant and simple technology so I had to have one. It used the power of a fall in the river to drive a piston that in turn pumped the required water uphill to a tank. It needed a fall of about 1.2 metres and our river had rapids that fell much more than that fairly close to out electric pump inlet. The rapids needed to be slightly controlled by creating a weir of big rocks 1.2 m high. The 10 m long drive pipe for the pump would feed through the weir. The cost of the pump and the labour needed to prepare the site was equivalent to about 5 year’s electricity for the electric pump, but rationality was by now submerged under a froth of excitement.

John thought this was a great idea especially if the excess water from the Glockemann was pumped to his place. Do you need a hand he asked. I ignored him till I found I needed his help. Over the millennia the river had flushed lots of large boulders down our rapids. To create the weir, all we had to do was move these boulders up stream into a pile thus restoring the ecology of the past. At least that was my excuse for blocking the river. I had tried hard to manually lever these boulders up stream, but it was physically too difficult to achieve without pulled muscles and crushed toes.

Like all farmers, John enjoyed playing with tractors. He arrived on his machine pulling a trailer load of hawsers, wire ropes, pulleys and chains, and extra man power in the form of his daughter Jennifer, wife Jill and Basil. The tractor was positioned on a flat piece of ground upstream of the boulders and the wire ropes were threaded through pulleys attached to appropriately-positioned trees so that the pull of the tractor was converted into a force straight up the river. The chains were fastened around the boulders, one by one, and to the wire rope, and the tractor pulled them up to the growing weir. It was brilliant. Manpower was required only to position the boulders within the weir. It took a morning instead of the week I had mentally allocated to the job.

The weir leaked almost as much as if it wasn’t there. But that was largely fixed by putting weed mat on the upstream side of the weir wall and over the stream floor and semi-sealing it with Bentonite clay. I had placed and capped the 10 m long by 15 cm plastic drive tube in the wall before we started. When the cap was temporarily removed the resultant gush looked enough to power the whole Snowy Mountains hydro scheme. This was so much more fun than having an electric pump.

Glockemann came to install the pump at the outlet of the drive pipe and inlet of the 2 inch pipe going up to the header tank some 30 metres higher. It took an hour of wading in the creek, attaching the pump to bed rock with chains. We opened the flow into the drive tube, adjusted the controls on the pump, and hey presto, it worked; free water at our tank and time for a celebratory drink while writing the required cheque.

City and town people just turn on the tap and feel very let down if the water doesn’t come out fast and clean. They get upset when the costs rise. In the country we have the advantage of finding and tapping our own water and maintaining our systems in balance with nature. We are lucky.