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Arapiles Bore Dry but business as usual 29-Oct-2008 At 8:19:40 PM Capt_mulch

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What does "stopped working" mean? Did they put way too big a spear pump down and pump it faster than it would recharge? You have to work out the recharge rate on a bore, i.e. you pump it with the right sized pump so that it will give a sustainable flow (say, 10 litres a minute), and when the flow rate drops off, you stop pumping. You then pump again in say six hours and see if you get the ten litres a minute again, and for how long. Working out bore yield is no exact science - you have to sit there for weeks working with the pump rate, length of time you are pumping, and how long it takes to recharge the surrounding soil to give that pump rate. You are not working with an underground stream here, more like an underground sponge. Get a big sponge that is wet, and squeeze it. If you squeeze it hard (high pumping rate), the sponge runs dry fast. How long does the sponge take to get fully wet again (recharge rate)? - depends how much water is around it. You have to work out how fast you are squeezing the sponge (pumping), compared to how fast the sponge gets fully wet again.

I know this 'cause ten years ago I spent $10,000 putting down a 90 metre bore for a nursery, then spending the next 2 months with a stopwatch and a 10 litre bucket working out that the bore could only sustainably yield 1500 litres a day. To give 1500 sustainable litres a day I had to pump 3 times a day (every eight hours), yielding 500 litres each pumping cycle. Any more pumping than that, and I would get less water.