Pumping water from lake 100' below for sprinkler system

[Sysop]

You can't pull water up 100', it isn't physically possible to lift it more than 33.9' and that is only going to happen at sea level.

Two line pumps do it out of wells all the time. They set above the ground and shoot a stream of water down to a foot valve which uses a venturi effect to draw water out of the well. Same is commonly done to bring water uphill from ponds. Sometimes more than 100'...

 

[vtsnowedin]

Well as this is a tractor forum I'd be tempted to use my tractor to auger a post hole/ well a few feet back from the shore that would tap into the lakes water table. Drop a eight inch pipe drilled with lots of one eight inch holes at the bottom two feet into the angered hole and back fill around it with pea stone. Then drop in whatever pump I wanted and set it at 100 psi to overcome the head and friction losses to get the water up to my distribution system.

 

[STx]

Two line pumps do it out of wells all the time. They set above the ground and shoot a stream of water down to a foot valve which uses a venturi effect to draw water out of the well. Same is commonly done to bring water uphill from ponds. Sometimes more than 100'...

That's not pulling, it's pushing.

 

[vtsnowedin]

That's not pulling, it's pushing.

You guys are both right so lets not get into a spring skunk contest over it.
Stx is correct that you can't suck water higher then 33.9 feet without creating a vacuum. And sysop is correct that you can get around that by using the venturi effect to push the water up to 100 feet but that means you move a lot of the water twice so it is inefficient but sometimes the best solution. The best plan is to place a big enough pump down close to the water level and have it push the water one time up to the height of the desired use. .

 

[Sysop]

My thinking is actually that there's more than one way to skin this particular cat. There are a number of solutions that can be made to work and work well. The main determining factor on what is best for the OP is what is most available to him at reasonable cost. There are a lot of "best solutions" out there, but each is determined by a specific set of circumstances.

 

[dragoneggs]

Why not dig a 'sump' next to the pond and pull the water into that, have your filter system in that container with a removable lid for filter/pump maintenance? 100ft is a lot of head so your pump will be sizable. Sounds like a great project. I am starting to plan a waterfall/river down to a pond and want a recycle design I am less than 100ft but close so listening here.

Clean filtered water would be a priority in my design which should translate to less maintenance. You don't want to be screwing around with clogged heads.

 

[BruceWard]

The hill to the lake is a 30 degree slope so drilling a well close to the lake is near impossible.

I would like to be able to run a hose bib for the garden from the sprinkler line so a pressure tank and pressure switch combination is ideal for me.

Using approximate numbers, 44 PSI is equivalent to 100 feet of head. Does that mean that a 45 PSI pump will only provide 1 PSI and very little flow to the top end? Do I need a 90 PSI pump to have 45 PSI at the top end?

To those discussing suction. My pump will be within 10' vertical of the water. I am not trying to suck 100' I am trying to pump 100' of head over 500' of line beyond the pump.

 

[Nelstomlinson]

Fire pumps are not required to have over-current protection on their circuit. Since the circuit will be outside essentially all the way, I would take advantage of that for the added reliability. Just put the fire pump on a dedicated circuit with no fuses or breaker. You still need a disconnecting means. You should probably run a second circuit down there if you want to have power at the pump house. You might be able to invoke some tap rule to power a panel off the fire pump circuit, but I wouldn't go there.

Your circuit is going to be long enough that you will need to oversize your conductors for the voltage drop. Don't forget you have to oversize your ground to match! An alternative would be a little boost transformer down by the pump, but fatter copper cables is a better plan. If you can find a pump with a 440V single phase motor, you can use a little step-up transformer to give you 480V from 240V and save on copper. Remember, you have to size your conductors to provide the motor's start up current at the motor's minimum allowed voltage. That start up current is bigger than the run current. A 220V motor is likely to need +/- 10%, so about 198V minimum. If you start with 240V at your panel, you can handle a maximum of 240-198=42V drop, but I'd definitely shoot for much less voltage drop than that.

Do you need to size the pump for the flow of all the sprinklers, or for just a few? I think a dozen sprinklers will require a lot of gallons per minute, right? You are likely to need a big pump, with a big motor, and some fat copper cables to power it. Compute how many feet per minute the water will have to flow in your pipe to deliver the necessary gallons per minute. If the flow is too fast, you will have big friction losses. I don't know how fast is too fast. A fatter water pipe is going to have slower flow and less friction.

How do you plan to test and maintain this pump? You should definitely have a plan for regular testing and maintenance - if you don't use it regularly, it won't work when you need it.

Is freezing ever going to be an issue? A dry system is an easy fix for that, but might complicate the testing and maintenance.

 

[vtsnowedin]

Do I need a 90 PSI pump to have 45 PSI at the top end?

To those discussing suction. My pump will be within 10' vertical of the water. I am not trying to suck 100' I am trying to pump 100' of head over 500' of line beyond the pump.

Yes and due to friction losses in the 500 ft of pipe a 100 psi output would be better.

 

[STx]

The hill to the lake is a 30 degree slope so drilling a well close to the lake is near impossible.

I would like to be able to run a hose bib for the garden from the sprinkler line so a pressure tank and pressure switch combination is ideal for me.

Using approximate numbers, 44 PSI is equivalent to 100 feet of head. Does that mean that a 45 PSI pump will only provide 1 PSI and very little flow to the top end? Do I need a 90 PSI pump to have 45 PSI at the top end?

To those discussing suction. My pump will be within 10' vertical of the water. I am not trying to suck 100' I am trying to pump 100' of head over 500' of line beyond the pump.

You really need to do your design, calculate your friction and head losses and then size your pump accordingly. Pipe size will also make a difference in this. It will probably cost you less than $200 to consult with a professional that will be able to answer your questions with specifics rather than the generalities you're going to get on the Internet. Nobody can tell you for certain what you need without either visiting your site or seeing a design. I made a LOT of money in irrigation fixing poor design because people thought they could do it themselves or hired unqualified contractors, you don't want to be one of those guys. The actual installation isn't all that difficult but there is a LOT to consider in proper design. A small investment now will save a lot of headache and expense in the future.

Here is a list from IA for Arkansas, I'd go with one of the CID's -

Jason Cook, CID, CLIAIA MemberEPA WaterSense Partner
Keeling Company
PO Box 15310
Little Rock, AR 72231-5310
Tel: (501)786-0958
coojas@hotmail.com
Available for Hire: Yes

Mitchell D. Langley, CIDIA MemberEPA WaterSense Partner
Irrigation Consultant
MDL Consulting
2829 W Country Club Rd
Searcy, AR 72143-9684
Tel: (501) 305-0202
mdlconsulting@cablelynx.com
Available for Hire: No

Rodney A. Patton, BSA, Med., CIC, CLIAIA MemberEPA WaterSense Partner
CAM AR/TN/OK
NDS
80 Mill Creek Dr
Greenbrier, AR 72058-9042
Tel: (501) 339-4850
rodneypatton@ndspro.com
Available for Hire: No

David Watkins, CID
CEI Engineering Associates
3108 SW Regency Pkwy Ste 2
Bentonville, AR 72712-7847
Tel: (479) 273-9472
dwatkins@ceieng.com
Available for Hire: No