Lately I have been thinking about planting a fruit orchard in the paddock, mostly because I’m fed up with mowing the grass all the time. An orchard will fill some of the bare space with something useful.
To grow the fruit trees, I’d like an abundant supply of cheap, clean water. The geologist in me suggests that since I live in a palaeo flood plain and only 10m above sea level, the water table can’t be particularly deep. So a water bore is in order. Hopefully I can locate a suitable shallow perched aquifer in the loose sediment. If not, the highly fractured metamorphic basement in my area is probably pretty permeable, though hard to drill. I plan to use a hand auger while the ground is soft enough. Once things get too tough I will build a percussion rig of some sort.
I made a start on the bore on the weekend. My first step was to buy a cheap hand auger from the local hardware store. Drilling in the relatively dry, stony soil was frustrating as the soil kept falling out of the auger and I could not get the “cuttings” to the surface. The solution was to pour a bucket of water and few handfuls of bentonite clay down the hole occasionally. With the addition of the mud, the loose soil became very sticky and easy to retrieve with the auger.
I had soon drilled as far as the auger would allow (1m). However, I was making good progress so the decision was made to weld in an extension using 25mm pipe and keep going. It seems a shame to cut a perfectly good $70 auger in half, but I still see it as good value given that it cost some orders of magnitude less than having the bore drilled commercially!
All up, the auger is now probably about 4m long (see below), and I have drilled about 3m. No water so far and the going is getting tough, with lots of stones and very little soil. This weekend I will try to drill the remaining length of the auger and then it will be time to switch to some sort of homebuilt cable percussion rig.
