Lake water for garden

[bcallaha]

We live on an 11 acre lake. I'm wanting to pump water from the lake to use for various purposes, chief among those is watering the gardens. The lake is about 75 ft from my barn, which has electricity. I'm thinking that I want to put the pump and tank in the barn, and run the suction line to the lake, 75 ft away. The floor of the barn is about 5' higher than the lake surface. The lake level doesn't fluctuate. I want to put in maybe 3 hydrants that will be at barn-level, from 5 to 100 ft away from the barn.

I know that pushing water is more efficient than pulling it, but I don't want to put the pump and tank at the lake if I can avoid it. Will this approach work?

Any advice is appreciated.

Brad

[lakngulf]

Not sure if I can be of any help or not, but I use lake water for my yard irrigation, including garden. The pump is on the opposite side of the shed pictured below. My intake line runs several feet out into the lake, because the lake is let down 10 feet every year. I do not know exactly how far out it goes, but I know it goes more than 25 steps, which would be 75 feet.



I use a 2ph pump and the intake line is 1 1/2 inch. I get great pressure and volume.

[tedln]

I have a lot more experience working with industrial pumps where you have "head" or pressure on the low pressure side of the pump. When you don't have water pressure on the low pressure side of the pump, the pump must be able to suck or create a vacuum to pull the water to it. The longer the line is on the inlet side and the lower in elevation the source is, the more difficult it is to actually pump. I am really curious what kind of pump LnG is using to pull water from the lake after the elevation drops ten feet. Centrifugal or reciprocating? Do you have to prime the pump with water in order to establish suction?

Ted

[lakngulf]

I have a lot more experience working with industrial pumps where you have "head" or pressure on the low pressure side of the pump. When you don't have water pressure on the low pressure side of the pump, the pump must be able to suck or create a vacuum to pull the water to it. The longer the line is on the inlet side and the lower in elevation the source is, the more difficult it is to actually pump. I am really curious what kind of pump LnG is using to pull water from the lake after the elevation drops ten feet. Centrifugal or reciprocating? Do you have to prime the pump with water in order to establish suction?

Ted

Ted, I do have to prime the pump each spring to get my irrigation going, and it takes awhile to get the air out of the line. I do not know enough about it to know centrifugal or reciprocating. It is one LONG pipe out into the water. I do not move it back or forth based on water level. Each winter I take off the intake valve and let it drain. So much of the pipe is exposed on the shore that it would freeze on me otherwise.

Before this pump I had another type that might be like you describe. I still had to prime it each spring, but it was two pipes running out into the water, one smaller than the other. I understood it to help with the intake at the valve, but I know little about pumps and pipes.

My lake neighbor has the same setup I have now, with the single pipe. But he is back in a slough and has to run his pipe a farther distance to stay in water. Back in 2007 we had a severe drought and the water level dropped almost 17 feet in July. So to water his yard he had to extend his pipe by almost 50 feet. So I know this method will pull water a LONG way.

Does that answer your question?

[tedln]

LnG,

It does, thank you. I know so little about that type of pump; but the fact that you prime it in the spring answers my questions. I am curious about how they are rated for output when the suction line and source elevation can vary so much.

I guess, if I built a pond; I would go to tractor supply or somewhere like that and buy one. Do they ask how far it needs to pull the water or do they simply ask what horse power motor you need?

Ted

[tedln]

LnG,

You answered a question I've been thinking about since they caught some folks growing about 1/4 acre of marijuana back in the woods on another guys property. The property owner found a newly buried plastic line from his pond back to the wooded acreage. When he followed the line, he found the cultivated marijuana. That was all reported in the newspaper. I kept trying to figure out why he didn't see the pump sitting next to the pond. If they work as you say, the pump could have also been hidden in the woods. Now I am trying to figure out how they got electricity to the pump without anyones knowledge. Who know's, if my garden fizzles on me next year; I may want to grow a cash crop. I guess they could have been running one of those Honda EU 2000 generators. They run so quite, no one could hear it.



Ted

[bcallaha]

lakngulf,
Sounds like you have a similar set-up as what I'm looking for. From what I understand about pumping water from my research, it's not so much about how far, but how much lift that's the determining factor in the pump you select. If you were to guess, how much elevation from your pump to the lake surface? Do you have a pressure tank? When you get a chance, please give me as much information about your pump and set up as you can.....like, do you have a filter on the suction end, check valve, mgf of pump, model, etc.

Thanks for all your help!!

Brad

[garden5]

Do you know what make/model the pump is? That may help us out? I'm wondering if there are benefits to using lake water over hose water. Perhaps more biological life in the water?

[bcallaha]

garden5,
From what I've read, there are benefits from using lake water over treated water. If you have any run-off of the lake water from irrigation, it will go right back into the lake. No possibility of chemicals, such as chlorine or floride getting into your lake. There is supposed to be minor benefits from the contents of the lake water also. I'm looking at this is a way to save money. I watered my garden 3 times last year, and it cost me $5 each time I watered it. I need to do something, or just let nature take it's course.

Brad

[tedln]

bcallha,

Your right in assuming the lift (or ability of the pump to pull water) is most important. The distance is of less importance, but due to line friction (literally the friction of the fluid against the pipe walls) pumps do have limitations based primarily on horse power available and applied to the pump. A check valve in the suction line would seem necessary. The check valve could also be built into the pump. I think a relief valve for recirculation would also be necessary to allow you to close the spigots without having to shut the pump down first. A pressure activated relay to turn the electricity on and off would do the same thing. With the relay, when you close all spigots, the pressure would open the relay stopping the pump. When you open a spigot, the drop in pressure would close the relay starting the pump. A pump could have all of that built into the pump assembly and they probably do.

Ted

[franktank232]

I would assume lake water would be very similar to rain water. I use well water here, and the problem i have is the pH (very high/hard) and temp...very cold....even now after a scorcher of a summer. I was actually filling up black barrels with well water, letting them warm in the sun and then watering plants (tropicals)... I would think lake water would be perfect; warm, acidic, and possible nutrient rich.

[lakngulf]

I have tried to include a link below that is pretty close to the pump I purchased from Lowes a couple of years ago. Here are some answers to questions asked.

(1) The pump has a 1.5 inch pipe intake and I have 1.5 pipe run to a central point in the area I irrigate
(2) I do not use an air pressure tank to store water and trigger a switch. The pump runs off an 9 zone irrigation controller that activates a relay switch to turn the pump on. There has to be some place for the water to go or the pressure will find a weak spot in the pipe, or make a weak spot.
(3) At various locations off the main line (before any irrigation valves) I have installed 6 or 7 spigots to run regular water hose. These can be on when ANY zone of the system is on. These are very handy for hand watering, washing a boat, and hooking up a sprinkler for the grandkids
(4) The intake valve does have a semi filter. It is coned shapped and looks like a strainer. It has a rubber ball that closes off when there is no suction from the pump
(5) It probably sits 12 - 15 feet below the pump level.
(6) The lake water temp gets fairly warm during the heat of the summer.
(7) I do not think my pump is a sophisticated as tedln has described. I have never tried to run it without some place for the water to go, so I do not know if it would auto shut off or not. I do not plan to learn.
(8) My yard is sloped such that any over-irrigation simply runs back into the lake. One of my zones is a home-made rock water fountain, and most of that runs back into the lake



These two pictures might help with idea of amount of drop---pump to intake



2.0 HP pump is somthing like this

http://www.lowes.com/pd_313834-57366-UT ... a=20$Ntt=2

[garden5]

Frank, I never thought about the consequences of the PH of my well water ....and we do have hard water! I'll have to do a PH test of it. Thanks for bringing up a good point.

[bcallaha]

lakngulf,
Thanks for the info on your set-up. You've got a nice set-up there. I may just do this next spring!!

Brad

[lakngulf]

Good luck with it. I tackled mine as a DIY project, but could not have done it without help from these folks:

http://www.sprinklerwarehouse.com/Sprin ... -s/777.htm

I ordered most of the parts from them, and got lots of email advice.