setting up a pump for irrigation; need advice

[canuckamuck]

I am going to be doing a few rai of Oolong tea. I have a little chunk of land that is bowl shaped and there is lots of room for a pond in the middle.

I have made no decisions yet about what pump or size of pipes, or will I just pump uphill to tanks and then have a drip system.

Even the pond is not yet dug. So I have a chance to start off right, because you all are so smart.

All I have done so far is I have begun to terrace the hillside in 50 cm high tiers.

What size of pump should I get? No electricity available there yet. I was thinking I could use the diesel motor from the father inlaws iron buffalo. But it is pretty old and possibly will be more trouble than it's worth.

What size of pipes, is there a science to it?

Should I run sprinklers from a pump down below, or should I run water up to tanks and have it come back by gravity. If by gravity should it be a drip system or a sprinkler system?

We are looking at about 4 or 5 rai with about 10 - 15 meters of elevation.

Thanks in advance

[Canada]

If it is bowl shaped, what is the radius of the bowl? And from the centerpoint to the outermost point, there is an increase in elevation of 10 meters? or 15?

Do you have a well already? Do you know any of the specs of the well? Has it been used before? Or did you just have it drilled? After you dig the pond, are you planning to pump that (pond) water up hill? How will you fill the pond? Rain? Do you or will you have a well to fill the pond and then pump it up from the pond or just direct to the top from the well and let nature take care of the pond.

Lots of questions.

Drip irrigation requires pressure. You need to calculate your tank height and the resulting pressure achieved from that height. You can also build a tower which will put the tank even higher. Without calculating first, I'd venture a guess there will not be enough pressure for a drip system of any size.

I'm not an educated guy, okay? But i've been doing quite a bit of well drilling, pump fitting and installing, Thai irrigation, and then drip irrigation over the last 2 years. With the little bit of information that you have given, I would have a good well drilled (uniform diameter and deep) Thais call them "Boh Air" as the drilling rig uses air to pump the dirt and rock out of the hole. It'll cost you about 30,000 baht. Then I'd buy and have installed a "turbine pump". (You have a 6" well drilled and the pump will be 4".) Then I'd pump the water up the hill and then down the drip lines. No need for a tank at the top unless you have other uses for the water.

Just guessing, I'd say you have about a 50 meter radius which means you are pumping up hill for a distance of 50 meters and an elevation of 10-15 meters (this is where I get lost), but it's not a long run up or down. You should be able to use 2" pvc which matches the outlet on your turbine pump head. There is a science to figuring this stuff out and I was good at math in my youth, but that was a long time ago. Anyways, at the top of the run you install a "filter system" for your drip line and then run 2" pipe along the circumference of your "bowl" with 5/8" drip line running downhill off of that. It's pretty easy actually. And the parts are all cheap aside from the well and pump. The bonus of the pump is that it is not going to get stolen, and you just roll your iron buffalo up to it, run a belt to it, fire your motor up and you are pumping water. The turbine pump that I witnessed looked like it put out as much as my 2HP submersible which pumps 200 litres a minute. You also have a good well and pump to fill your pond, if it is not rainy season. No need for electricity, generators, submersible pumps which you risk getting stolen if you leave it out there.

Somebody else may be able to actually calculate your requirements whereas I cannot. I'm just guessing. Personally, I'd ask a lot of questions then just go ahead and drill a well and try it. I just re-read your post and see you are planting tea and you are terracing. So your configuration for drip will be a little different than what I am used to doing but it should still work, you do need to pump the water up the hill first with your 2" line and then downhill with the drip. Trying to drip uphill does not work well. I've tried that. You'll need to experiment to find the optimum length of drip line for your "running system". Then just open and close valves to achieve this as you move the water around. You may be able to drip 5 rai at a time but it will depend on total length of drip line. We usually run 2-3 kms at a time depending on how far we have to pump the water and how much grade.

Sprinklers. Hmm. May work better I don't know. They are less efficient than drip, and you water all the dirt, not just the dirt were your tea trees are. That means weeds. I know very little about sprinklers maybe someone can enlighten the both of us.

Hope this helps.

Edited May 20, 2014 by Canada

[canuckamuck]

Thanks Canada, I think I can fill in a few blanks now. The bowl is fairly steep, so the run is short. I said the height is about 15 meters, what I should have said was that is as high as I will plant the tea at first. The entire bowl is about 30 meters elevation.

I do not need a well, I am building a dam on a small stream about 300 meters away. The pond will be filled by gravity feed through a pipe.

I would love to know how to work out how much drip line I can run on one set. I don't know how much water comes out of each nozzle/hole. and i do not know how water will be coming out the 2 " inch pipe at elevation. But I think it will have to be trial and error. Also, i might not be able to use the iron buffalo (it might be knackered) so I also need to know what alternative pump motor combinations could work for me, and what horsepower is needed.

It's early days now, no equipment purchased yet, Thanks for your help so far

[Canada]

Thanks Canada, I think I can fill in a few blanks now. The bowl is fairly steep, so the run is short. I said the height is about 15 meters, what I should have said was that is as high as I will plant the tea at first. The entire bowl is about 30 meters elevation.

I do not need a well, I am building a dam on a small stream about 300 meters away. The pond will be filled by gravity feed through a pipe.

I would love to know how to work out how much drip line I can run on one set. I don't know how much water comes out of each nozzle/hole. and i do not know how water will be coming out the 2 " inch pipe at elevation. But I think it will have to be trial and error. Also, i might not be able to use the iron buffalo (it might be knackered) so I also need to know what alternative pump motor combinations could work for me, and what horsepower is needed.

It's early days now, no equipment purchased yet, Thanks for your help so far

Are you saying that the bowl is 30 meters higher at the rim than at the centre? And it's only 5 rai. That's a cup, not a bowl.

So you are feeding the pond from the dam. So you are pumping water for irrigation from the dam as well. It would not make sense to pump it up from the pond. You should be able to use a cheap centrifugal pump run off of an iron buffalo. You can buy small diesel motor and pump set ups, I don't know how much they cost, you'll have to go check them out yourself. A centrifugal ump will cost about 4,000 baht for a new one. Rebuild the iron buffalo would be fairly cheap too. But cheap is a "relative" word. 5000 baht to me is cheap, to a broke Thai farmer it is way expensive. I am moving quickly in the direction of being a broke thai farmer so my definition of cheap is also moving.

Drip line length will depend on your water supply pressure. Set it up so you can easily adjust it with valves on relatively short runs or sections. All the drip stuff you can buy at Global. It's pretty cheap. There's that word again.

Anyways, good luck.

[Canada]

Oh, BTW pre made 5/8 " dripline output is about 2 litres per hour per drip. You can buy it in different drip spacings of 10, 20 or 30 cm. Alternatively, if your trees are widely spaced you can run PE pipe/hose and punch your own holes at your required spacing and plug your drippers into that. It really depends on how you design your system and what your requirements are. Pre made drip "tape" rather, it is called, is cheap and easy, but the spacing of the holes may be too close for your needs. So the project gets a little more expensive.

[canuckamuck]

I am sorry to confuse things, I should have given more information at the beginning. The entire bowl is about 9 rai. My intention was for the bottom half to be in tea. I have not decided about the top half, but it is there. I was thinking it would be too high to do it all.

I don't know why you think it would be better to pump from the dam. The dam is 300 meters away and the supply is small. I will need a pond as a catchment so that I can pump as much as I like and then let it refill. Surely It must require less energy to pump water 15 meters uphill, then it does to pump it 300 meters and then uphill.

Thank you for info on drip pipes, this is the sort of stuff I have no clue about.

[Canada]

I like your signature line at the bottom. Fitting.

[Canada]

Drill a well. Pump it up the hill then down.

[canuckamuck]

Ok, we can just disagree about the well part. I get the water for free year round and the source is uphill from the future pond, so no well pump or well needed. Also i don't think I can get a drilling rig in there. I am already scratching my head about how to squeeze an excavator in there. The entrance is blocked with a shed and fruit trees. something will have to go.

I just need to run some pipes. I already have a a pipe run that is twice that long supplying my fish farm and it runs 24/7 with very little maintenance.

[DerkMR]

The issue will be the pump pressure.

I bought a 4.5 hp Honda pump which had a 4" (?) hose and pumped like a max of 5 m elevation.

On equal level it makes around 140 m3/h, with 3 m elevation it's less than a third.

If you construct a PVC system due to the ridgidity and smaller diameter you geht higher, but for 15 m you need more power or do it in steps, eg. 3 times pumping 5 m elevation each

Bye,

Derk

[Pacificperson]

A couple of thoughts: first you need to account for the pressure difference in your drip lines between the highest and lowest terraces. Fifteen meters is equal to about 1.5 bars, so if you pressurize the whole system at once the lower terraces are going to get a lot more water than the upper terraces. You could valve your system into three bands: an upper a middle and a lower, then the pressure differences in band would only be about a half a bar.

Second, terraces don't eliminate erosion problems, they simply relocate them, hopefully, to where they are easier to control. You might want to slope your terraces to the midpoint of the bowl and collect the water in a sluice running into your pond. If as you said the slope is steep and the run is short, making the sluice of concrete might save a lot of headaches.

[canuckamuck]

Thanks guys. I am going to look at some pumps today, but i must admit I have no experience pumping uphill. I will be posting more questions shortly.

As far as the drip lines are concerned, I do expect to set it all up in zones to equalize pressure. I am somewhat tempted to go with sprinklers, but logic suggest drips are more efficient with the water.

I really hope I wont need to make concrete sluices.

Derk, can a PVC pipe contain the pressure required to get water up 15 meters. I am wondering if I should only go 10 or 12.

[Jotham79]

I am sorry to confuse things, I should have given more information at the beginning. The entire bowl is about 9 rai. My intention was for the bottom half to be in tea. I have not decided about the top half, but it is there. I was thinking it would be too high to do it all.

I don't know why you think it would be better to pump from the dam. The dam is 300 meters away and the supply is small. I will need a pond as a catchment so that I can pump as much as I like and then let it refill. Surely It must require less energy to pump water 15 meters uphill, then it does to pump it 300 meters and then uphill.

Thank you for info on drip pipes, this is the sort of stuff I have no clue about.

" I get the water for free year round and the source is uphill from the future pond......Surely It must require less energy to pump water 15 meters uphill, then it does to pump it 300 meters and then uphill." Not if the dam is uphill from the top of your bowl.....you could gravity feed directly from the dam and not have to pump up hill at all. I understand the flow rate is small, but if there is enough water being delivered from your source is not enough you will have other problems. In any case the higher the water from which you are pumping up the hill the less power you will need. So the higher you can build your catchment the less power you will need to pump. .

You have 9 rai total with a vertical 30 meter height.....What is the horizontal run in the direction up the hill? Did you measure this height or is it estimated?

Everything here sounds very good. You need to make sure that when you are talking heights you are talking straight vertical distances which will determine the pressure needed. There are pumps that will do different volumes at different pressure heads so this is the tricky part. In general the larger diameter discharge the larger the power requirements (proportional to the square of the diameter) to get it pumped up a hill. Large diameter pumps are usually used here for very low lifts. I use a 2" pump for most of my sprinklers as I get the best pressure/volume characteristics that way, but as mentioned earlier a lot is lost. Pressure is also lost in distance from friction, but the slower the flow (ie larger the diameter) the less the loss.

It would be great to see some photos of this project when you are done.

[canuckamuck]

The height of the hill is based on Google Earth. I would love to know how to measure the elevation of a hill. Perhaps I could download a GPS ap for my phone and try that. Once the hill is terraced I will be able to make an accurate assessment of the height of the rows because I am going up in consistent 50 cm steps

Would it better to go with an 1"1/2 pump for a higher elevation. That would reduce the volume, but increase the range of the pump.

I was thinking 2" pump, but I am guessing.

As far as the catchment is concerned I really only have the choice of a gravity fed pond. I can not make a reservoir at the source. I can only make a small dam to bring up the level for consistent supply. This would not be good enough for pumping from because of seasonal fluctuations. It will be sufficient to keep a pond filled year round though.

[Jotham79]

I agree with all of the size recommendations given earlier. I like a 2 inch pump, but I need a certain volume to make pumping worth while. You just need to be aware that not all 2 " pumps will perform the same. Find out what pressure it can deliver (for your engine) and then know that for every 10 meters vertical you lose 1 atmosphere of pressure. For PSI every vertical 10 meters will cost you around 15 PSI. Use what ever units for pressure are given and that will tell you the max height (subtract a little for inefficiencies).

You are probably pretty close on the height, but you can make a couple of 3 meter errors could make a big difference. Cut a path from bottom to top in a straight line and make 2 large L squares (2m x 2 m). Move and measure as you go up the slope and add up all of your measurements. This will be a miserable job. You could do it with a tall bamboo pole of fixed height and a level. Go up the hill til you are level with the top of the bamboo then bring up the pole and go again.

I either case you want to gravity feed from your source to the highest point possible and pump from there. If it is 3 meters above the old pond you can go up another 3 meters and you can gravity feed some and save fuel.

[canuckamuck]

I was looking at some pumps today. The one I am considering is a 5hp diesel 2" it says it has max head of 21M but rated for 15m.

Does this seem appropriate?

I will try to get the actual height figured out some time this week. It is possible that I will keep it below 15m

[Jotham79]

I was looking at some pumps today. The one I am considering is a 5hp diesel 2" it says it has max head of 21M but rated for 15m.

Does this seem appropriate?

I will try to get the actual height figured out some time this week. It is possible that I will keep it below 15m

I've only ever used a kwai lek or an old Kubota motor on a trailer, but this sounds pretty good.

[DerkMR]

I was looking at some pumps today. The one I am considering is a 5hp diesel 2" it says it has max head of 21M but rated for 15m.

Does this seem appropriate?

I will try to get the actual height figured out some time this week. It is possible that I will keep it below 15m

If the max is 21 m, then it means at this level the water comes out in small drops

But 21 m means it gives a pressure of around 2.1 bar, unfortunately also the PVC will "take" a part of the capacity due to friction. So don't expect a high output at 15 m and keep the PVC as straight as possible, so no 90° angles!

Bye,

Derk

[canuckamuck]

Is there a way to figure out the actual output at 15m? I guess I would have to know the output at level 0.

They have a 7.5 hp diesel as well, but it is a 3" and I forget the max head on that. Would it be possible to reduce it to a 2" without putting too much pressure on the pump. and If I did would I gain more flow at 15m than I would with the 5 hp 2"?

Should I use metal pipe for the first 10m of lift? would that help me retain pressure because of rigidity?

Lots of questions, but why not ask right? I need to know this stuff.

[Jotham79]

Is there a way to figure out the actual output at 15m? I guess I would have to know the output at level 0.

They have a 7.5 hp diesel as well, but it is a 3" and I forget the max head on that. Would it be possible to reduce it to a 2" without putting too much pressure on the pump. and If I did would I gain more flow at 15m than I would with the 5 hp 2"?

Should I use metal pipe for the first 10m of lift? would that help me retain pressure because of rigidity?

Lots of questions, but why not ask right? I need to know this stuff.

I would go get all of your measurements first. I would not go with a larger diameter, but increasing power "may" be useful ( Iike the Kubotas). Pipe rigidity should not be an issue (a plastic hose will due) assuming it will withstand the pressure. As Mr Derk said "no 90 degree angles" use slow gradual bends whenever possible. If you are pumping to a tank and then gravity feeding from there, flow rate up is not that big of an issue. Something to consider would be to pump irrigation up the first few meters from your pond.The higher the pressure head you go for then the more issue you will have with seals.

I like the idea of drip irrigation in your situation, but consider a large sprinkler for the bottom. You can direct them and mine could probably hit 5+ meters vertical with a horizontal range of 15-20 meters (at max elevation). If you can give me the head, diameter of the sprinkler opening, and slope, I could give you the uphill distance you could expect to reach. This is getting to be a pretty interesting exercise.

You should go visit some people using sprinklers and drip and see the range of pressures they experience and what is physically happening. I don't know about your area, but here we have a store that will sell the supplies or will come out and design and install a system.

Completely different direction: You could put a bunch of corrugated metal roofing up on top and catch rain for your uphill tank. The plus would be that during the rainy season you could channel the excess water down a drain to prevent erosion.

[DerkMR]

Is there a way to figure out the actual output at 15m? I guess I would have to know the output at level 0.

They have a 7.5 hp diesel as well, but it is a 3" and I forget the max head on that. Would it be possible to reduce it to a 2" without putting too much pressure on the pump. and If I did would I gain more flow at 15m than I would with the 5 hp 2"?

Should I use metal pipe for the first 10m of lift? would that help me retain pressure because of rigidity?

Lots of questions, but why not ask right? I need to know this stuff.

You could calculate the output but you would have to google for the formulas.

You definitely need th output at level 0 which vry few pumps have given. When I bought a pump I took the only one with this figure

Reducing diameter is not good as the pump already has to build up a lot of pressure.

Bye,

Derk

[Jotham79]

Is there a way to figure out the actual output at 15m? I guess I would have to know the output at level 0.

They have a 7.5 hp diesel as well, but it is a 3" and I forget the max head on that. Would it be possible to reduce it to a 2" without putting too much pressure on the pump. and If I did would I gain more flow at 15m than I would with the 5 hp 2"?

Should I use metal pipe for the first 10m of lift? would that help me retain pressure because of rigidity?

Lots of questions, but why not ask right? I need to know this stuff.

You could calculate the output but you would have to google for the formulas.

You definitely need th output at level 0 which vry few pumps have given. When I bought a pump I took the only one with this figure

Reducing diameter is not good as the pump already has to build up a lot of pressure.

Bye,

Derk

It is called Torricelli equation and I have it already (plus a little trig). All I need is the pressure ( don't really need the diameter unless we get into volume). if the sprinkler is elevated, I need that elevation.

I agree that you should not reduce the output diameter. If the pump has a 2" discharge nothing will be gained and the smaller diameter pipe will probably have increased loss due to friction.

[DerkMR]

Is there a way to figure out the actual output at 15m? I guess I would have to know the output at level 0.

They have a 7.5 hp diesel as well, but it is a 3" and I forget the max head on that. Would it be possible to reduce it to a 2" without putting too much pressure on the pump. and If I did would I gain more flow at 15m than I would with the 5 hp 2"?

Should I use metal pipe for the first 10m of lift? would that help me retain pressure because of rigidity?

Lots of questions, but why not ask right? I need to know this stuff.

You could calculate the output but you would have to google for the formulas.

You definitely need th output at level 0 which vry few pumps have given. When I bought a pump I took the only one with this figure

Reducing diameter is not good as the pump already has to build up a lot of pressure.

Bye,

Derk

It is called Torricelli equation and I have it already (plus a little trig). All I need is the pressure ( don't really need the diameter unless we get into volume). if the sprinkler is elevated, I need that elevation.

I agree that you should not reduce the output diameter. If the pump has a 2" discharge nothing will be gained and the smaller diameter pipe will probably have increased loss due to friction.

To get it completely correct you need the friction of the tube material and the diameter, else you are around 30-50% off with this level of elevation and the pump pressure

Bye,

Derk

[canuckamuck]

Interesting stuff, I will have to get back to you guys with the elevation when I get it. But now I have guests for a couple of days.

[canuckamuck]

Bringing this thread back to life. I got the pond in, it's holding water. I got all the tea planted in the rainy season. and I know my elevations.

This week I need to make a filtration system for the pump.

I have no experience running drip tape, so does anyone here know what type of filtration is required to keep the system from plugging up.

Also any models or images of filtration setups would be greatly appreciated.

[rice555]

Go to the company that makes you DT and see what they recommend.

120-130 micron??

rice555

[canuckamuck]

Ok

[slapout]

Maybe I missed it but if the pond were dug at the highest level of the farm it could gravity feed your planted crop land, no pump needed Slope your terraces correctly and flood irrigation from top to bottom reqires no pipe, etc. To answer the question first, you cross the planted acrage with several small hand dug canels so as no plants are subjected to long peroids of wet roots. One man can flood irrigate 100 acres a day and drive a tractor doing other farm work.

[canuckamuck]

I apologize for al the confusion. too much discussion earlier about water supply.

The pond is at the bottom, there is no way to have it higher because the water comes to it from another coulee by pipe but It won't go uphill.

This is a pic of the pond being dug. Pond is full and ready to go.

[canuckamuck]

Here is a couple more pics,

Early days

A panaromic but it doesn't show around the corner

Edited December 14, 2014 by canuckamuck