Irrigation economics and logistics

[gocards1177]

Before I just go buy a gas water pump, I'm seriously considering a DIY wind pump like this: Waterpumping Windmill - Yggdrasil - YouTube

Before I attempt that, I would think that the diaphragm pump they show wouldn't generate much head. Correct? If I was to build a similar setup, but then rig it to a crank-type water pump like a transfer pump, would that generate 20-30 feet of head? What kind of pump could be cranked or oscillated relatively slowly and generate that much head? If this runs continuously, and I'm only using a couple hundred gallons per week, I'm not looking for a huge volume.

 

[gocards1177]

Been awhile since I d up over the posted to this thread. Got a gas pump hooked up over the weekend. Works great. Probably pumps about 30 gpm. I zip tied a treated plank of plywood to the top to provide protection from rain.

 

[gocards1177]

I hope no one minds if I resurect this thread. I have a new irrigation problem to discuss. But first, just to pick up where it left off...

For summer of 2013 and the first part of summer 2014, I used the trash pump from the pond. We expanded our orchard to almost 40 trees and they're thriving! At the end of July 2014 we had a well put in. Simply amazing! The trash pump/pond water worked OK, but the pump I had was finicky. The trees didn't seem to mind.

Now I have a new irrigation question. On another part of our land I have a 300' row of 45 water-loving hybrid willow trees. They're doing OK, but I think they would do better if I could water them regularly. The problem is that they're approximately 2000' down the driveway from my well. Fortunately they're in a low lying area of the property and I put two 300 gallon IBC totes on the hillside above them providing abut 40 feet of head. This is then connected by 250 feet of 1/2" PE tubing to a drip system to the trees. Ideally I'd like to give each tree about 3-5 gallons per daythrough August/September. In order to fill the IBC tanks I've been using two 55 gallon plastic barrels on pallet forks on my loader. I put blukheads with 1 1/2" valves on the bottoms of the barrels to empty. A round trip fill/move/empty/return cycle with the barrels takes about 20 minutes. It works OK for what it is, but what I'd really like to do is run a dedicated water line.

So that's where my question comes in. I'm considering running 1/2" PE tubing from my closest hydrant to the IBC tanks. It's approximately 1800' distance with maybe 20' elevation change (with the hydrant being higher than the tanks). Over the span of the distance there would be a "valley" of probably 20 feet. At my well, I have 50 PSI and my well produces about 8 gpm. Even if I had to leave my water supply on 24/7, I would only need 0.06 GPM to produce all the water I need. Can someone verify with the parameters I've given that I could generate that flow? Also, could I get away with 1/4" or 3/8" (cheapter) tubing? If I get the green light on this, initially I would just lay it on the side of the driveway. After verifying that it works I would then go back and bury the tubing using my sub-soiler.

Thanks again for any advice.

BTW, for anyone that was following my Barn Build thread, I apologize for not keeping up with the posts. I haven't forgoten, I've just been busy!

 

[gocards1177]

Anyone?

 

[gghb]

I run about 400"of thin wall 1/2" poly drip line header it serves about 2000" 0f 5/8" jd drip line i think you could put 1800" 0f 1/2 or 03/4 thin wall poly from your hydrant to you orchard drip line opperated with a $40 timer and get it done with no packing water. to charge drip line requires very little flow if you use low flo emitters. Greg


i would use a 1/4 drip tube down each row and run for several hours at a time than let dry some and hit it hard again on whatever schedule your soil requires but run long for deep root growth

 

[boggen]

my first issue is if air gets into the line. and needing enough "velocity" feet per second (think miles per hour) of water running through pipe to clear the air out of the line.

second issue is "water hammering" turn off a valve after that much water gets moving, and you may be replacing things from water hammer effects alone.

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with above i suggest min a "hydrant" at highest point/s in the line. so if you need to, you can open up the garden fauct and let air out. think of it as air bleeder valve. but able to hook up a garden hose if wanted.

to lazy to look up actual "head loss / pressure loss" for that length, but would advise going with a larger size hose / pipe. what is going to happen with a small diameter hose = a lot of pressure, then 1 minute later it will go down to a trickle of water. due to the pump is not only having to push water up a hill, but it is also having to push water through the entire length of pipe. (pushing water through pipe) is were head loss / pressure loss is coming into play.

going with a larger diameter hose = less pressure / head loss. i would say 3/4" min, and push for up to 1" in hose size. this should make sure that you get water when you actually need it, and just not for irrigation like you are wanting now.

when i say 3/4" or 1" i am reffering to nominal size. different hoses and pipes have different inside diameters i forget right off but black poly pipe errr most of it comes in black color (polyethylene pipe) get some rated around 100PSI. for cheaper cost. at around 1" should be fairly cheap compared to other alternatives. if you go with pex like pipe for direct burial you might need to increase pipe size in order to get the inside diameter up to snuff per say.

EDIT: some folks might state going bigger inside diameter. again to lazy to check actual GPM and overall length.

would advise installing some sort of "water hammering resister" before any valves.

would advise getting some playsand (nice clean sand no rocks in it) put a little bit in bottom of trench, put pipe in and put some more on top of it. ((better websites detail about how to compact dirt / sand around pipes better)) this is more for protection of the pipe, but also water hamming that might cause hose to shake and move a tiny bit once in the ground.

would advise kinda snaking (weaving) the hose into the trench. you don't want hose nice and tight and straight in trench, but a little back and for weaving kinda like a snake. this should help keep the hose in better condition long term.

make sure ya get the pipe below the frost line for your area. it stinks having to get it deeper. but over that much ground and only getting it a few inches to a foot or so deep = a truck / tractor (something heavy and carrying a load) = damage to the hose. not to mention any sort of wash out that might happen when ya redo things. and having hose end up being exposed.

it might be worth while to special order and get hose on one large reel. vs trying to connect multi shorter hoses you can buy quickly at local hardware stores.

pressure test the hose and major connections before putting dirt back into trench to cover it up. ((fill entire hose up with water., then make shift something up to pressure test it with an air compressor. MORE WATER = BETTER and SAFER, avoid pressure testing with a bunch of air in line. things can get ugly))

 

[PandDLong]

I think 1800' and a 1/2" pipe is a long run with too small a pipe. I would not be confident that any water would arrive into your tanks. Personally, I would hate to buy that much pipe and lay it only to have it deliver no water. Even if it did happen, would it be reasonable to have your well pump going full-time for this one task?

I don't have my pipe friction loss calculators handy but I believe you need to upsize your pipe size. Is there a way to eliminate/reduce the valley? That may be the difference maker given you just need a low flow at the tank and it may be the determining factor for pipe size?

 

[gocards1177]

I'm with you guys. I had already decided on 3/4" pipe but I appreciate the posts. I'm not worrying about frost lines. The area and slope I'm laying it on will allow for easy draining before winter with one valve. I've also decided to go with 20' sticks of bell-end Pvc. I'll rip the planned path with my subsoiler and then pull it in a few sections at a time. I'll try to take some pics when I do it. Thanks again

 

[gocards1177]

Well I got in about 1300' of 3/4" pvc. That's all he local Lowe's had. The good news is that my final destination is the same elevation as where I got to and I was able to measure the flow to 5-6 gallons per minute. Good enough for me! Thanks again for he advice.

 

[gocards1177]

This is where it connects to the hydrant (obviously).