When the well runs dry

[Gweiloman]

52 minutes ago, dick turpin said:

 

 

Will get my spade out and go for the 20 metres.

 

Another thought comes to mind, if going the borehole 

route could it be put down the existing well hole and

thus save a few metres of initial drilling.

 

Otherwise, might send up the cloud-seeding drone.

To add on to what @Mike Lister said, the pipe needs to be supported. If you  send it down a few metres without support, I imagine that it would vibrate violently when the pump is sucking up the water.

[Gweiloman]

45 minutes ago, Mike Lister said:

Bore hole drillers don't lend themselves to starting on excavated land, just to save a couple of meters drilling, the equipment needs a flat surface to start. We have two wells, one at 15 meters and one at 35 meters, ths cost was 1k per meter but will likely be much more now I imagine. The chances of finding an aquifer are not great, most bores depend on collecting water for several meters of strata through seepage. Our water table in the North is still good, around 6 meters....fingers crossed.

I’m confused. I wouldn’t have thought that water seepage alone would produce enough water for a bore hole well. I always thought that the well feed pipe has to be actually submerged in water?

[Mike Lister]

You will need consider the type of pump you will need, based on the depth of the well. A standard centrifugal pump has a maximum lift of 10 meters and nothing you do can change that, despite what the sales guys tell you, it's down to physics at that pint. 

 

The next step up is a jet pump which is more pricey and more complex but it will get you to 25 feet.

 

After that, it's down to a deep well submersible pump like a Franklin which will life water hundred of feet.

 

For most people it's a choice between number one and number 3.

[Mike Lister]

3 minutes ago, Gweiloman said:

I’m confused. I wouldn’t have thought that water seepage alone would produce enough water for a bore hole well. I always thought that the well feed pipe has to be actually submerged in water?

The bottom four meters of pipe are slotted which means water enters the pipe in that range but the water supply come from many many layers in the rock strata all the way from near ground level to the natural level of the water table. At some point the feed pipe hits the water table which must be closer to the surface than the bottom of the pipe. So yes, the pipe is submerged in water but that's not an aquifer, that's the water table or the level of water across a large area. As the pump removes water from the bore it is replaced by seepage as the water table levels out. An aquifer is typically a large pool  or body of water, often under pressure. Most wells don't hit one of them, instead they get their supply from the rock strata that pools in the pipe.

 

If I use my 15 meter well pump in the evening it will at times begin to run dry. If I leave it until the following morning, the water table will have leveled out and the water in the pipe will have risen and my pump becomes useable again. This happens because nearby farmers draw on the same water supply, albeit a mile away, and that causes water in my well to flow into their bores that supply their water.

[brianthainess]

On 5/6/2024 at 1:25 AM, soi3eddie said:

Can't remember the cost but it was not outrageous (or would not have done it).   

Where I live to have a proper bore, first you need permission from the Amphur, they charge between 100k-130k guaranteed water. They go about 25 meters deep. A huge very noisy truck mounted rig is used.

A self dug well does not need permission, and each concrete ring costs about 1k plus labour.

[Mike Lister]

6 minutes ago, brianthainess said:

Where I live to have a proper bore, first you need permission from the Amphur, they charge between 100k-130k guaranteed water. They go about 25 meters deep. A huge very noisy truck mounted rig is used.

A self dug well does not need permission, and each concrete ring costs about 1k plus labour.

That is massively expensive, 1k baht per meter is the going rate in the North and that also uses a truck mounted jig

[impulse]

1 minute ago, Mike Lister said:

That is massively expensive, 1k baht per meter is the going rate in the North and that also uses a truck mounted jig

 

You also have to consider what's included.  Is that a turnkey well, with pump, controller, cable, downhole pipe and surface pipe?  Or just a borehole that someone else will have to equip?

 

[Mike Lister]

On this business of aquifers':

 

Not everyone has a large pool of water or aquifers sat directly under their property or bore hole site, in fact I doubt many people do. Most people rely of a bore haul that collects water from rock strata rather than tapping into a large underwater pond. The op needs to finds out what the water table level is in his area, this is the level at which water is first available and changes based on the season. Knowing the dry season water table level will help him better plane the depth of his well.

[dick turpin]

Just now, brianthainess said:

Where I live to have a proper bore, first you need permission from the Amphur, they charge between 100k-130k guaranteed water. They go about 25 meters deep. A huge very noisy truck mounted rig is used.

A self dug well does not need permission, and each concrete ring costs about 1k plus labour.

 

Think officially you need permission from the Ampur, but most private dwellings,

don't bother(including us) as it is difficult to check, but larger hotels and resorts

around us do have to go the formal route.

 

[Mike Lister]

Just now, impulse said:

 

You also have to consider what's included.  Is that a turnkey well, with pump, controller, cable, downhole pipe and surface pipe?  Or just a borehole that someone else will have to equip?

 

Yes, agreed

[dick turpin]

Just now, Gweiloman said:

To add on to what @Mike Lister said, the pipe needs to be supported. If you  send it down a few metres without support, I imagine that it would vibrate violently when the pump is sucking up the water.

 

Have since decided to leave the existing well intact as a useful

back-up when water returns and instead look at other means of

digging/drilling deeper. 

 

[impulse]

31 minutes ago, brianthainess said:

Where I live to have a proper bore, first you need permission from the Amphur,

 

Where that's the case, I'd hope they keep records that will help figure out how deep your neighbors' wells are and which ones had to be redrilled because they weren't deep enough during the dry season.  In any case, it would be worth a visit to the section that does the permitting before spending a wad of money on an improvement that can make a huge difference in the livability of your home.  Or you can rely on the experience of the drillers who should know.

 

[Gweiloman]

48 minutes ago, Mike Lister said:

You will need consider the type of pump you will need, based on the depth of the well. A standard centrifugal pump has a maximum lift of 10 meters and nothing you do can change that, despite what the sales guys tell you, it's down to physics at that pint. 

 

The next step up is a jet pump which is more pricey and more complex but it will get you to 25 feet.

 

After that, it's down to a deep well submersible pump like a Franklin which will life water hundred of feet.

 

For most people it's a choice between number one and number 3.

 

38 minutes ago, Mike Lister said:

The bottom four meters of pipe are slotted which means water enters the pipe in that range but the water supply come from many many layers in the rock strata all the way from near ground level to the natural level of the water table. At some point the feed pipe hits the water table which must be closer to the surface than the bottom of the pipe. So yes, the pipe is submerged in water but that's not an aquifer, that's the water table or the level of water across a large area. As the pump removes water from the bore it is replaced by seepage as the water table levels out. An aquifer is typically a large pool  or body of water, often under pressure. Most wells don't hit one of them, instead they get their supply from the rock strata that pools in the pipe.

 

If I use my 15 meter well pump in the evening it will at times begin to run dry. If I leave it until the following morning, the water table will have leveled out and the water in the pipe will have risen and my pump becomes useable again. This happens because nearby farmers draw on the same water supply, albeit a mile away, and that causes water in my well to flow into their bores that supply their water.

Thanks a million. Very useful information and I have learnt a lot more.

[Gweiloman]

38 minutes ago, brianthainess said:

Where I live to have a proper bore, first you need permission from the Amphur, they charge between 100k-130k guaranteed water. They go about 25 meters deep. A huge very noisy truck mounted rig is used.

A self dug well does not need permission, and each concrete ring costs about 1k plus labour.

 

31 minutes ago, Mike Lister said:

That is massively expensive, 1k baht per meter is the going rate in the North and that also uses a truck mounted jig

As I mentioned earlier, in my friend’s case, they were asking for Thb 100k, guaranteed water. I’m not sure if he would have to obtain permission from the amphur or just the land owner. Probably both. We were told that someone paid Thb 180k further up the hillside. This is in Phrao which is quite an elevated area so I guess they were having to dig really deep.

[Chris Daley]

Put the last few drops in some bottles and put the price up 10 times.

[impulse]

Not that I recommend it, but there are some YouTubes made by guys who "drill" their own water wells in the USA using pumps and PVC pipe to jet down to potable water zones.  Works a treat in soft and sandy soil.

 

But may not be legal in Thailand.  It's certainly not legal where they're doing it in the USA, but they're the off-grid crowd.  If you do go that way, make sure you disinfect the borehole with chlorine bleach or you can screw up your aquifer.  And thoroughly and justifiably piss off the neighbors.

 

I'd post a link or 3, but YouTube is blocked where I'm staying.

 

[seajae]

we have been getting 2000 ltrs of water delivered twice a week now for several weeks so we can water our trees, the water table keeps dropping due to others having automatic watering systems and raised tanks to run them, they are constantly filling the raised tanks that supply their automatic systems from their ringed wells which drains our well, we get to water for 2 hours with 2000 ltrs before it dissapears. We have no choice as the trees will dies if we dont do it, our dam has around 20cm of water in it and we are trying to get at least 16000 ltrs delivered so we can water the trees on the opposite side, we normally have to do this each year but this year it has been a lot worse with the heat, just a part of living in Thailand, house well is around 40 mtrs and still providing the house water thankfully, it is the dam and the ringed well that are running out of water, the water table is generally only around 2 metres below the surface and we have never had to fill the well  before but now with the heat and all the water use by ohers with propeties adjoining ours we have no choice, hopefully the wet season will hit very soon

[Mike Lister]

22 minutes ago, Gweiloman said:

 

As I mentioned earlier, in my friend’s case, they were asking for Thb 100k, guaranteed water. I’m not sure if he would have to obtain permission from the amphur or just the land owner. Probably both. We were told that someone paid Thb 180k further up the hillside. This is in Phrao which is quite an elevated area so I guess they were having to dig really deep.

 

Even though you're at a higher elevation, the area that you live in will have its own water table, often because rainfall is trapped in the rock and can't drop further. They say that water finds its own level, which it does, unless its contained within rock and can't get to a lower level. It's therefore easily possible to have a decent usable water supply contained inside the mountain that you live on, even though it's much higher than ground level.

[simon43]

1 hour ago, Mike Lister said:

You will need consider the type of pump you will need, based on the depth of the well. A standard centrifugal pump has a maximum lift of 10 meters and nothing you do can change that, despite what the sales guys tell you, it's down to physics at that pint. 

...

Pint or point? 🙂  As Mike says, a standard centrifugal pump can only 'suck' up to a maximum of 10.34 meters depth, regardless of how powerful the pump is. (Actually it has nothing to do with sucking, more to do with atmospheric pressure..)

 

Workman dug a well at one of my little hotels on Phuket Island about 12 years ago, lined with concrete rings.  The overall depth of the well was 12 metres and the building supervisor couldn't understand why the brand new well pump could not 'suck' up the water from the bottom of the well.

 

Solution?  Tie a strong rope around the well pump and suspend it a few metres down the well! Looked messy but it worked.....

 

[brianthainess]

1 hour ago, impulse said:

 

Where that's the case, I'd hope they keep records that will help figure out how deep your neighbors' wells are and which ones had to be redrilled because they weren't deep enough during the dry season.  In any case, it would be worth a visit to the section that does the permitting before spending a wad of money on an improvement that can make a huge difference in the livability of your home.  Or you can rely on the experience of the drillers who should know.

 

Koh Chang not sure if that is the whole Island, but you are paying the 'Council' so you get a receipt, therefore records are kept TTBOMK.

I have never heard of a bore going dry, they drill a lot deeper maybe 25meters, than just the ground water, which is around 8-10 meters below ground, near me, and that price includes the wide blue PVC pipe, you buy the pump.  

[impulse]

9 minutes ago, brianthainess said:

I have never heard of a bore going dry, they drill a lot deeper maybe 25meters, than just the ground water, which is around 8-10 meters below ground, near me, and that price includes the wide blue PVC pipe, you buy the pump.  

 

Not to get too detailed, but the reason they'd go to 25 meters is generally because the wells drilled to 10, 15, or 20 meters have gone dry.  Maybe permanently dry, or maybe seasonally dry.

 

It's a combination of where they find porous rock that holds the water (the reservoir- generally it's not a cavern- it's porous rock), and the pressure of the water at that depth.  It's quite possible to find water 1000 meters down at a pressure that's high enough that you don't even need a pump.  That's referred to as an artesian well.

 

Realizing that it's dangerous to project US or Euro standards on Thailand, generally the entity that doles out the well permits also collects well records from the drillers that can be a wealth of information for anyone contemplating drilling a well in the area.  How deep they had to drill, whether they set pipe and how deep, whether they grouted the pipe, etc.  Maybe they don't collect those drilling reports (TIT), but it's worth a check to see if they have that information to plan your own well.

 

[dick turpin]

Hurrah......heavy rain in Isaan last night.

[brianthainess]

42 minutes ago, dick turpin said:

Hurrah......heavy rain in Isaan last night.

Same here on KC, on and off downpours for 24hrs now.

Just to say my 'Town water' comes from bores, and my 3000 liter tanks have not run dry, in fact we've been running on just a I,000liter tank for weeks, and the missus waters the durian trees every few days. Tanks fill overnight, if no pressure in the day. 

[Sticky Rice Balls]

On 5/5/2024 at 9:56 PM, dick turpin said:

 

Calm down

jai yen yen 🙂

[PJ71]

But tanks ( or vats ) and collect rainwater.

[dick turpin]

Just now, PJ71 said:

But tanks ( or vats ) and collect rainwater.

  

Sorry, where do we collect rainwater from... only joking.

Have since been deluged with some mega storms and

every butt is over-flowing.

 

The good news is we seem to have resolved the issue

with the well, which has backfilled with ground water.

 

Also, had the village water guru, at his suggestion,

fit a wider diameter pipe with a bigger "flute" on the 

end to improve water flow, that's 800 baht am not

going to see again.