Gettin pretty worried ere

[Boots]

Is there anyone out there that knows much about underground water? I am getting pretty worried about life as us humans are living it at the moment...

As our dams (and bores) continue to dry up, folks are slamming in bores left, right and centre. Is this sucking the very life out of our earth or what???

The Sunshine Coast Council have been suggesting people drop bores to counter the town water problems.

Surely it can't be good. I swear I can hear the planet gasping.

[ina]

Is this sucking the very life out of our earth or what???

It is. Might be a short term help, but not a long term solution.

[Wombat]

G'Day boots,

I have seen years ago how much faster we are pumping the water out of the Great Artesian Basin, and I do remember it was lots!

Nev

[nick]

depends on how far down they plan on putting bores, it will cost quite a bit so should put people off for at least a little while. if someone does get a drilling rig in and hits nothing but dirt, it will put a lot of people off.
we have found that the underground streams have been influenced by the river flow.

dept of water has now put low security water users (dairy farms and lucerne growers) on about 10% allocation with dam levels at 39%. if the dam levels drop to 36%, there will be a full cut.
high security (mines) apparently have allocation cuts............

and town still not on any water restrictions..............

lots of water coming out of the ground and rivers with next to nothing going back. something has to give soon.

[Boots]

I think I would have to agree that underground water is relative to local rivers. We recently had a massive dam installed about 12km away, and I don't know if I am imagining it or not, but I swear all the surrounding areas are dying.

We have trees dying from the roots up and just falling over. It has been a long while since we have had decent rain, so maybe it is just that, but old timers have said they have never seen it so bad, and areas further away or not along the creeks do not seem to be in the same strife. Some farmers with up to a dozen dams have begun selling their stock because ALL their dams are dry. I always felt our dam may have been spring fed, because it held up when many others couldn't but levels have taken a massive dive since they began filling the major commercial dam down the road in September.

If anyone knows of any research in this area, I would really like to have a look at it.

[Stonehead]

Speaking from experience both here and in Oz, I'd say boreholes are a short-term solution. Combine lots of people extracting water with low rainfall and you will quickly find the boreholes running dry - even if they are 150-200 feet deep.

Also, much of the deep water is "old water", deposited hundreds or even thousands of years ago. So if you extract it like oil, then it will run out.

I'd suggest water conservation first, then rainwater harvesting and then good landscape management (to slow runoff and encourage soak). But, you have to bear in mind that all the water you keep on your place is less water for the people downstream from you.

It's far too complex a subject to go into now (I have to make dinner, for a start), but if you want I'll provide some details over the next few days, chores and jobs permitting.

Stonehead

PS For background, our borehole ran dry in January and we've been scraping by ever since; I've lived in the outback; and I've put together borehole systems, rainwater harvesting, working on land management and gone without washing for more than seven days at a time while working with pigs!!!

[Boots]

Well, it's not like the pigs mind, do they?

Am also wondering just how big an effect those keyline and contouring techniques have had on my dam level too, while you mention them... Spent ages putting in contours last year.

Am totally rethinking them now... I let it catch and soak across paddocks twice a year when it rains, OR I let it run, catch and store it in bulk and then disperse where needed all year...

What is the better option here, you think? Am beginning to think contouring is a crock... well, under our conditions anyway.

Would love to have Muddy think on this one. Whatchoo think Muddy? Do we adjust the lie of the land, to aid absorption, or do we aid the lie of the land to aid bulk collection? And once collected, do surrounding areas deplete a catchment? Is a large catchment more likely to evaporate and absorb than a series of small ones?

Fire away Stoney. Am keen to hear what people have done and what has worked for them. But don't speak with your mouth full mate. Have ya dinner first!

[Muddypause]

Would love to have Muddy think on this one. Whatchoo think Muddy? Do we adjust the lie of the land, to aid absorption, or do we aid the lie of the land to aid bulk collection? And once collected, do surrounding areas deplete a catchment?

Well, Boots, I've tried to formulate some thoughts several times about this, but the truth is you are in a situation that I, and I would guess most people in Britain, have no experience of at all. We are in a wet country here, and the current water shortage we have in the south east is not because there is no water about, but because there is a high density of population. The 'drought' conditions we are experiencing is due to demand rather than dryness. In reality, there is no drought at all, just high consumption. But you're facing practical challenges on a daily basis that few people here would consider doing. I really don't know enough about geology or hydrology to make many meaningfull comments.

Is a large catchment more likely to evaporate and absorb than a series of small ones?

This is in no way to be considered authoritative, but I would guess that total surface area is the main factor to consider in terms of storage - not only the top surface that will affect evaporation, but the surface between water and ground, that will affect absorption. Keep these to a minimum to reduce both. So I'm guessing that a single deep collection point may be better than two shallow ones. But how absorbent the ground is will need considering, too. And maybe pressure, as well (deeper water = higher pressure). Blimey, what a poser! I guess I don't know.

But I do think that water is different to other resouces that we consume; it's not like oil or gas reserves, or mineral deposits that we extract, because with those, once we have used them up they are gone forever. But we don't really consume water at all, we just use it - it goes in and it comes out again, whether into your washing machine, or your bath, or your body. It's amazing really - unlike food or air, we don't actually take anything out of the water, and nor do we change it in any way. We may add stuff to it (and that can be a problem, depending upon what we add and how much of it), but the actual water itself remains unchanged, and the total is undepleted.

I think the problem, in a macro-environmental way, is that the water doesn't always go to where we want it. This is to do with weather, climate and geology. If your underground aquifer is not being replenished as fast as you draw from it, then it would seem inevitable that eventually you will have to find other resources, or be forced to decamp. That, really, is the long and the short of it, but I guess there could be all sorts of politicking around that situation, as usually happens when a resource is in decline. For example, the person who draws the most from the aquifer could assume a position of power, and the small time user have little influence on how the resource is distributed. Or worse, you have someone who assumes outright control over of the whole resource.

In terms of pure geology, it would seem that many aquifers are sandwiched between layers of impervious rock, the water having got there by creeping along seams of porous rock, rather than simple having soaked through the ground from directly above. Depending upon the local rock strata, the supply to the aquifer that you have your borehole in may be remote from you.

The cycle of water seems very complicated; there seem to be two halves to it - weather and climate affect the 'top half' (where it rains), and geology affects the 'bottom half' (where it goes to afterwards). I read that water never stops moving, wherever it is, not only in terms of rivers and the sea, but following strata underground, collecting in aquifers, and then overspilling to form springs, eventually all to be sucked up again into the air by the influence of the sun, and circulate around the atmoshere. I've never really thought of this before, but I wonder just how much water there is below the surface of the ground at any moment?

I'm rambling away a little too much here, eh? And that's after I've just deleted another five paragraphs. I think, in short, Boots, I have failed to offer any constructive comments here, but it sure has been an interesting thinking about it.

[Wombat]

Is a large catchment more likely to evaporate and absorb than a series of small ones?

Going back to basic principles, the think to look at is surface are per unit volume, so I would think the lots of smaller catchments would be worse than one large one!

Nev

[Boots]

I will end up with a new dam once the mudbricking is finished... nowhere near the size of the big one, mind you, but a wee one that I'll just pump straight out of when it rains to fill the top tank, I guess.

It is interesting thinking with you Muddy... you went exactly where I did with the underground reserves... but I was considering a depleting resource. It isn't, huh? You mean even pee eventually breaks back down and returns to a state of water that is again consumable? That is a new concept - but glad to hear it.

...We don't pee as much as we drink though, do we? Sweat goes into the atmosphere... mmm ok, so it comes out somehow.

We have some beaches in South Aus with big long jetties. The jetties stick out heaps above the sea now, and I thought that was reduced water... but I must have been stuck in earth-is-flat thinking or something... it is just somewhere else? Like Blackpool? The simple stuff always amazes me!

I wondered what would happen when an underground source actually dried up, and wondered if the earth would compress to a point where the source no longer could exist there... but maybe not, if they are rock based to begin with... and exist like water formed channels or tunnels... Maybe they will just wait?

I really do think the whole contouring concept is not much chop here now. Which is kind of annoying, because I tackled it with such enthusiasm, thinking it would restore the slopes. I did have a nagging concern that I may be messing with my water supply, but the whole contouring thing is supposed to be about slowing water to better absorb on slopes, so I figured it would still get down to the dam. Unfortunately, I just don't think we have enough rain here to be messing with collection! (And they don't mention that when they are pitching it! ) Better to just keep the goats running down the dam inlet whenever possible and keep all water movement down to the dam as clear as possible, I think.

New fangled concepts... so often backfire. But we live and learn.

I have to stop stressing about this water situation *smacks cheek* and just keep reminding myself that like everything it is meant to go around. If worst comes to worst, I bring it in on a truck.

Bloody ell, it's cheaper than hay! Maybe I should have just done that to start with!

P.S Have just about run out of bricks, so the car will get my attention tomorrow. Will let you know how I get on.

[Stonehead]

I really do think the whole contouring concept is not much chop here now. Which is kind of annoying, because I tackled it with such enthusiasm, thinking it would restore the slopes. I did have a nagging concern that I may be messing with my water supply, but the whole contouring thing is supposed to be about slowing water to better absorb on slopes, so I figured it would still get down to the dam. Unfortunately, I just don't think we have enough rain here to be messing with collection! (And they don't mention that when they are pitching it! ) Better to just keep the goats running down the dam inlet whenever possible and keep all water movement down to the dam as clear as possible, I think.

Unfortunately, I'll have to be quick as I've a lot to do but...

Don't give up on the contouring! The problem is actually doing one thing in isolation - so contouring all your slopes without allowing for catchment can be detrimental as can the opposite.

What you need to do is get a good feel for your entire property, how your catchment area works, where the water goes (including where it goes off your place), and what the underlying geology is. You also need to know what your water consumption is throughout the year, when it peaks and when it troughs, and work out your losses due to evaporation, transpiration, leaks, and wildlife.

Then, you need to contour the slopes where you get the worst flash events (to slow the run-off) or where erosion is a risk. Your contours need to gradually turn up-slope until they reach the areas that you've decided will feed your catchments for your dams. Then, as the water banks up on the contours, any overflow will come out the ends and into your dams.

With your dams, you have to consider whether the Australian-style dam will hold enough for your needs, or whether the evaporation in the hottest months is too much. If the latter, you may need to consider a sand dam.

Wtih a sand dam, you back fill behind the dam wall with a mixture of gravel and sand to between a third of the height of the wall and the full height of the wall. Sand and gravel can hold between 30 and 35% of their volume in water, but with the advantage that once the water level is below the height of the sand, evaporation drops away markedly.

So, if you fill your dam to, say, one third of its height with sand and gravel, you only have one-third the capacity of water to that height but you have negligible losses to evaporation. With the right calculations, this may serve you for the three months of the year when evaporative losses are at their highest.

To extract the water, you sink a lined well shaft into the deepest part of the dam and extend it to just above the height of the dam wall (any lower and it will fill with silt when the dam fills). Run a pipe out on piers, with a pump in the bottom of the well and away you go. You will also need a ladder on the outside and inside of the well shaft so you can maintain it (and be wary of gas build up).

Also, it's worth considering having a spillway on larger dams - especially if you get flash events (ie sudden floods that fill your dam and then cause it to overflow). If you have a spillway below the top height of your dam, you can stop the dam wall being eroded away and collapsing. I've seen this happen twice in WA.

Anyway, must dash but will try to put some more details up later.

Stonehead

PS While a major contributing factor to the English drought is over consumption, there has also been a marked change in rainfall patterns and up here in NE Scotland, we've only had 50-60% of the average winter rainfall. I'll post figures later, too.

[hedgewizard]

I've never really thought of this before, but I wonder just how much water there is below the surface of the ground at any moment?

More than there was five minutes ago. *zips up*

Actually this thread has cheered me up because my garden takes the run-off from our development of 27 houses. All the water goes down a central gulley and everybody thinks it drops into a parallel dimension after that, but it doesn't - it goes into a soakaway under my grass which is now old and knackered so when it rains hard it shoots out of the ground and plays havoc with the top half of the garden.

I've been thinking of this as a problem - replacing the soakaway or laying drain to take it downslope - but I've realised that I really want to be laying a storage tank at the top of the garden and then a soakaway for the overflow. When I win the lottery, that is!

[Muddypause]

You mean even pee eventually breaks back down and returns to a state of water that is again consumable?

Hey, some people don't wait that long, and drink it straight from the... err... tap.

I thought that was reduced water... it is just somewhere else? Like Blackpool?

Yep. There's a chance that some of the water you are drinking was once peed by someone in Blackpool. Having been to Blackpool, it's probably best not to dwell on that too long.

I wondered what would happen when an underground source actually dried up, and wondered if the earth would compress to a point where the source no longer could exist there... but maybe not, if they are rock based to begin with... and exist like water formed channels or tunnels... Maybe they will just wait?

Well, I guess in the extreme long term, the ground is constatly moving, too. I suppose this is how the strata and fissures formed in the ground in the first place, which water can then collect in.

I really do think the whole contouring concept is not much chop here now. Which is kind of annoying, because I tackled it with such enthusiasm, thinking it would restore the slopes. I did have a nagging concern that I may be messing with my water supply, but the whole contouring thing is supposed to be about slowing water to better absorb on slopes, so I figured it would still get down to the dam.

I guess there are several things afoot here. Slowing the water down on the slopes to encourage absorption would be good for crops and plant life, and maybe also aid in the longer term replenishing of groundwater. But I wouldn't have thought it would assist in immediate water collection. But it's my (limited) understanding that your local geology will greatly affect all this, too.

[Boots]

eeeeeeeeeeewwwwwWWWWWWW!



urinologists, huh?

Have a mate who crossed the Simpson Desert by peeing in his radiator, but I never asked him what he drank while making that slow journey!

Eck.

I am sitting here with the flu, and nuffin... NUFFIN... would get me trying that as a cheap, available, medicinal treatment. Nope, just the thought ....

*shudder*

Not sure why, but it made me think of holy water... You know that funny tasting water they give you and touch your head with when you are a kid? Used to be in bowls at the door...

I always wanted to know what it was and where it came from. Everyone always just said the priest makes it.... Sure tasted weird. (Yes Nev, I know your not sposed to drink it... but kids do...and maybe that's why ya not supposed to??? )

Oh Hedgy... Ya can't just flip it out and shoot it out the window, mate. Bitta decorum, eh?
(That privilege is reserved for truckies that are really pressed for time .)

[Wombat]

Yep there are some things even I wouldn't do!

Nev