So I am in the foothills of
Fruška Gora, that's an outcropping in the former Pannonian Sea. We have a massive
water shortage problem due to lack of rain and inaccessibility of
city supplies, and few natural springs. But to get the pros in to drill a well down to unlimited water is prohibitively expensive - it's over 150 m (nearly 500 ft) to get to the Danube water table. However a shallower well of around 40 m (130 ft) can provide a limited supply (maybe a cubic metre a day, which isn't terrible for basic home and watering needs, though it probably isn't potable and will need filtering, which is OK). But even that is very expensive to get done professionally, so... I am crazy
enough to try and do it myself, on the cheap of
course.
It seems to me that cable percussion-type methods are very attractive - your percussion tool can double as both a "bit" to break up the material and as a bailer to lift out material, and a cable is much cheaper and easier to handle per metre than endless lengths of box steel extensions like for an auger. And "all you need" is an up/down motion, either by hand (OK, I am not that crazy), or more likely a fairly inexpensive electric winch on an improvised derrick. You don't need much more expensive, specialised equipment, or even much water to hand.
So how deep CAN you go with this method? Is it mostly just a time and effort thing? What are possible restrictions or deal-killers with this? If I plug away for weeks and weeks (yeah, my time costs money too, but I still have more of the former), making a few ft at a time, I feel like I would get into some sort of water eventually.
According to people around here who have already drilled
wells, after the first few metres of loamy/silty stuff (which would be supported with a guide casing) you get into some quite dense clay, which sounds like a pig to get through, but not as hard as rock, which we don't seem to have until you get waaay further down. At 40 m no-one has got into sand either, and that's why all the wells around here are of a quite low replenishment rate. That can maybe partially be offset by ensuring we have a long filter section at the bottom, and or trying to do some kind of gravel packing. I don't know how much further you would need to go to get into a nice sandy, water-bearing layer. But the plus side of the clay is it is self-supporting - according to the neighbours they did not need to case as they went down, although I would put down a PVC casing if I got into water and/or sand. Also, pulling up a bunch of clay would be great, I need some natural
pond liner, I'd do it just for that..!
Would love to hear your thoughts.
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