Hi everyone, first time poster here at permies.com - seems like a great community! I'm going to include a quick introduction below because I haven't seen anywhere on the forums to do so (I'm not that adept at computers, so I may have just missed it).
My partner and I have been building our own house on a piece of raw
land I bought some years ago. We've been doing everything ourselves, from clearing the land to framing, electrical and plumbing and everything in between. It's been a fun learning
experience, albeit stressful at times. We spent the first year living in an 8x12 cabin with no
water, and no insulation for the first half of the winter. Gotta make memories somehow!
We aren't exactly pioneering any groundbreaking ideas; we've stuck with conventional building methods to keep the red-tape people happy, we're tied to the electrical grid (but hopefully not forever), our plumbing runs to a septic system and drain field... but our goal is the same as many others have had for many years - to build ourselves a home with as small a
mortgage as possible so we can continue to live simply, grow our own food and enjoy the experiences life has to offer.
So now, on to my questions!
Water has been a big problem for us. I have a water license on a large, clean river across the road from us and had planned to make use of this by pumping and filtering from the river up to our house. Turns out the cost of horizontal boring under the rural road, having an engineer design a system and supervise all work (required by law here) we're looking at well over $20k. I considered having a deep well drilled, thinking we'd surely hit water with the river being so close however after speaking to neighbours within a few kilometres, we found out there is an impermeable clay layer along the river edge and people like us have drilled as deep as 500' without a drop of water. So that option quickly went out the window too.
I spent quite some time with my dowsing rods and marked out a half dozen spots around the property for a shallow well and started digging, and digging some more. I dug as deep as I could with a post hole digger (around 6') in the early spring and hit water here and there. As the seasons changed and we had a long spell of draught, the water dried up (to be expected, but you gotta stay hopeful). I finally witched a handful of other spots in the middle of draught season, dug a few more holes and finally hit water at 5' in one location. We're now well past the driest months of the year and the water level has stayed the same so I'm confident
enough to develop this into our water source.
What I have in a 1'x1' hole, 5' deep before hitting water. I
should point out that what I've hit is an
underground stream/spring, not a static water table. First few feet of digging were stiff clay then I was into the coarse sandy gravel water bearing layer, now I've got water, and below that is around the consistency of split
pea soup - lots of coarse gravel swimming around but no firm "bottom". There's bound to be some big rocks down there however I've only pulled a handful of palm sizes stones out. I managed to get nearly a foot deeper by using some very basic tools I made out of a few items anyone would have in their recycling bin (I can elaborate on that if anyone is interested). So now we're "around" 6 feet deep with close to a foot of water in the bottom of the hole, level hasn't dropped by more than 1/8" in the past month.
I have a few options and would appreciate some feedback from other minds. I will have an excavator there to bury a 7000l cistern (approx 1800 gallon) next week, so high yield from this water source isn't critical - that cistern will provide for
alot of our water needs without constantly pumping from the well.
Now that I've found water and have a good understanding how frail a spring can be, I'm a bit nervous about doing something like puncturing the impermeable layer below and losing the water..I'd never forgive myself for the rest of my life. The impermeable layer might very well be that deep layer of clay the neighbours have talked about, but I've no way to tell. This is what I'm thinking, any thoughts?
#1 - Drive a sandpoint as deep as I can and call it good. Upside is that this is a cheap and relatively easy. Since I'm already down to the water layer, I might not have much problem going deeper. The downside is that my water may be perched on an impermeable layer only a little deeper than I've dug. If I'm driving the well point into the unknown below, I could easily disturb the impermeable layer and lose the spring or not get deep enough to have enough static water above the screen during drawdown.
#2 - I'm having the 7000l cistern buried by an experienced operator, however he's leaving his machine there for a few days afterwards so I can rent it hourly and play around with some other less critical projects. I could easily dig that hole deeper, lay in a large metal or HDPE culvert vertically with slits cut in the bottom and develop it this way. Upside is that it's relatively cheap and easy to do, probably an afternoon
project for me. This seems like a good option although again, I'm worried about disrupting the spring with a large machine in there. I'd like to keep site disturbance to a minimum as well so I can easily seal the casing, but that's a minor concern really.
#3 - Try washing a 4" casing further down the hole. Once I have that cistern in place and filled (I'm allowed to pump from the river, across the road with a gas pump in a one-off situation like this), I'll have a fair bit of water to try washing a casing down. I think this could be a good option, but again I'm not sure how I'd be able to tell if I went too deep and lost the spring, also not sure if I would eventually (or quickly) hit larger rocks that I couldn't wash away.
#4 - Build myself some shoring and keep digging by hand. This is the safest (for preserving the spring, anyways) but I have alot of other things on the go, like finishing building our house - and this adds more exhausting work to an already exhausted guy. Once I got deeper, I could lay in a vertical casing, either 4" or 6" pvc or large metal or HDPE culvert with slits cut in the bottom and likely call it good.
Seeing as I'll have the excavator there next week and a bit of time to play, I'm leaning on trying to carefully do it this way. I know each situation is different, but I'm hoping to get a few second thoughts from other folks who likely know more than I before I get started one way or another. To re-iterate, my biggest fear is losing the spring - I don't know what's below..could be a bottomless aquifer or it could be perched on a fragile layer only a foot deeper.
If you've taken the time to read all this and could help me out, thanks so much!