3" trash/water pump limits - filling a pond??

MikeS_in_GA · Jun 2, 2005

3\" trash/water pump limits - filling a pond??

I'm interested in having a pond built. The dozer man said the spot looks great and is ready to go when I have the money. I'm not sure there is enough water to make the pond work. Pond would be about 1 acre in size. I have a well and water right there - but the well only does 20 gpm and I don't like the idea of running the well for months at a time.

I'm wondering if I could use a 3" pump and pull water out of the river to get it filled - and every now and then to keep it full. I was thinking about running 3" PVC pipe from the river and have it buried near the pond. Then I could take the pump out, hook it up and let it run when I needed to. Some of the 3" pumps are rated at over 500 gpm.

River is about 6 feet below the bank. Pond would be about 25-30 ft higher than the bank and 250-350 feet away. (will do some more measuring this weekend)

Does anyone know how a 3" or even a 4" pump would do pumping water through 250-350ft of pipe up a very gradual slope of 25 feet? I have a 2" pump that I use to fill my 300 gallon tank - it takes about 90 seconds to do that, but I am only using a 50 ft discharge hose.

Thanks for any input!

Mike

Soundguy · Jun 3, 2005

Re: 3\" trash/water pump limits - filling a pond??

We use trash pumps at work to drain wra's.. etc. Last one I picked up did about 16000 - 18000 GPH.

Id stick the pump close to the pond, so there isn't much lift and priming to do.. then let it force the water the 250 whatever feet to the pond. Thos pumps develop a good head.. still thats a decent run..

Soundguy

Deerlope · Jun 3, 2005

Re: 3\" trash/water pump limits - filling a pond??

Pumping that distance I would suggest increasing the discharge pipe to 4 or 6 inches.

Highbeam · Jun 3, 2005

Re: 3\" trash/water pump limits - filling a pond??

I agree, the pump needs to be by the river source since you can only suck so hard. I drained a pond with a 3" 5 or 6 HP Honda trash pump and it did amazingly well. Rent the pump for a day and give it a try. If you are allowed or feel you can get away with using the river then I would say that is a great source of water. Be sure to either remove the intake after use or hide it real well so the fish huggers don't see it.

A trash pump is a centrifugal pump so it can be overloaded and just stop pumping. The engine will still spin the impeller but no water. I think that 25-30 vertical feet is within reason but I would rent it first to try. The rental yard can also rent you fire type discharge hose.

Really, go down and rent the pump and hose and run the water to the point of your future pond just for the sake of proving to yourself that it can be done before investing tons of money on buried pipe and pond excavation.

have_blue · Jun 3, 2005

Re: 3\" trash/water pump limits - filling a pond??

Since suction is limited here on Earth, most pumps of that type only lift 20-26'. It doesn't matter whether the lift is gradual or straight up. In other words, the pump would never prime that high up.

The solution is to place the pump closer to the river, or compromise so that you are lifting no more than ~10 feet and the pump will prime real quick. That way you push the water instead of suck it, and have (theoretically) unlimited power.

I used to have to pump water OUT of my pond ever time it rained. You would be surprised at how much water even a 2" pump can move in 12 hours. I think a 3 incher with 5 or 6 HP would be more than enough for a 1 acre pond.

MikeS_in_GA · Jun 3, 2005

Re: 3\" trash/water pump limits - filling a pond??

I guess I wasn't clear enough in my first post. I am planning on having the pump at the river, and only dealing with a short lift and a long discharge run. I've tested this with my 2" pump and it self primes in about 30 seconds and will shoot water 15 feet in the air out of the end of the discharge hose. I've only used a 50' discharge hose with my 2" pump. I'm just not sure how it would work using a 300' discharge pipe.

I checked at one rental place, and they only have 100' of discharge pipe for their pumps. I'm renting a cement mixer tomorrow, so I will ask there as well. Good idea to do a practice run first - I can try that. I would sure hate to spend 8K on a pond that I can't keep full.

Mike

MikeS_in_GA · Jun 3, 2005

Re: 3\" trash/water pump limits - filling a pond??

( I I've tested this with my 2" pump and it self primes in about 30 seconds and will shoot water 15 feet in the air out of the end of the discharge hose. )

On second thought I can get a tree soaked up to about 15 feet in the air - subtract my height with arm raised - so water comes out about 8 feet or so - still a very impressive sight.

have_blue · Jun 3, 2005

Re: 3\" trash/water pump limits - filling a pond??

( ( I've tested this with my 2" pump and it self primes in about 30 seconds and will shoot water 15 feet in the air out of the end of the discharge hose. )

On second thought I can get a tree soaked up to about 15 feet in the air - subtract my height with arm raised - so water comes out about 8 feet or so - still a very impressive sight. )

I know what you mean. Mine shoots almost like a fire hose. I have to be careful with it. It eats holes in the ground, and I quickly get tired of fighting it. I always end up submerging it to stop the madness.

Steve_Miller · Jun 3, 2005

Re: 3\" trash/water pump limits - filling a pond??

My pond is 400 feet from the river and I have a 2" trash pump pushing thru 400 feet of hose. It is very slow at best, I could fill my well in about 45 minutes (approx 1500 gallons). The vertical push would be about 20 feet and the pump had to suck about 4-5 feet. Once my well filled I would throw it in the pond and let it go for a few hours. Hope this helps. Off to the cottage for the weekend.

Steve

DKinWA · Jun 3, 2005

Re: 3\" trash/water pump limits - filling a pond??

I've been called a lot of things, but now it looks like I need to add "fish hugger" to the list. Until you've seen a farmer pump thousands of juvenile coho salmon onto a farm field, you can't begin to imagine the damage some of these pumps do in rivers. Improperly screened/positioned water intakes (both legal and illegal) in Washington costs anglers and taxpayers thousands of dollars every year. Yes, I do get upset when someone cuts into my fishing time, so I'll leave it at that and step down from the podium /forums/images/graemlins/blush.gif