Changing supply sources - approach question

cooper5114

LawnSite Member
Location
columbia, sc
Today I pull water from a river and the pump can supply about 25gpm. It’s been a royal pain to deal with the river and I’m thinking of pulling from my well instead. But the well cannot supply water at that rate. So here’s what I’m thinking....

could I install a holding tank large enough to supply my biggest zone and fill that from the well. My thought were to connect that holding tank to the house supply and keep it pressurized. So normally it would be completely full and under pressure.

then I would supply the irrigation system from that tank...essentially move the pump from the river to be the pump that pulls water from the tank and supplies the irrigation system. As soon as the irrigation system opens both pumps would run — one pumping water out (to zones) of the tank and the well pumping water back in (from well) until it’s full and under pressure again

make sense? Any other ideas how to take an undersized well and have it deliver water to a bigger demand system.

thanks much and first post in a long while.
Bob
 

greenmonster304

LawnSite Platinum Member
Location
You Know
How much water does your well make? How many zones do you have? How often do you irrigate. You can’t have the tank “under pressure” it would have to be static with a float style fill valve with. The second pump would be pressure it’s your main line.

My first thought without knowing all the details about your system is that this won’t work well. If you are using 25 gpm you will need a really big tank.

What are the issues you are having with the river supply? Maybe your efforts would be better applied to improving that.
 
OP
cooper5114

cooper5114

LawnSite Member
Location
columbia, sc
The well puts about 12gpm based on the tag but i have not measure it. I can get into the river issues but first i'd like to understand why what i'm proposing will not work.

Tank size....sure maybe 1000 gallon tank at the most.

So a couple questions.

1) why can't the tank be under pressure and tied to the house water supply? To me there's no need for float...just when the pressure drops the well pump will come as usual.

2) the second pump today turns on when the valves open...any issues with this? i could also put a pressure tank on this side and keep the irrigation system under pressure and just have the second pump turn on when a value opens.

i really appreciate any feedback and happy to talk about the issues w/the river setup but first i'd like to understand the issues w/the direction i'm considering
 

RhettMan

LawnSite Gold Member
Location
Texas
Tank need not be pressurized, only vented.

Well Pump activated/shut off by a float-relay type switch contraption that disconnects circuit when tank is full.

Dont connect to house, it would require more components, etc.

Is this the same well that supplies the house? If so a float valve? Use the accepted non cross-connection air gap for fill.

But the tank must be vented or the stronger pump will put a suction on the house plumbing, and just be in general: funky.
 
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greenmonster304

LawnSite Platinum Member
Location
You Know
Please describe your current system in more detail.
if you are going to use a holding tank you need to know how much water you will use for each zone. A 1000 gallons won’t last long even with a 12 gpm well filling it if you are pulling 25 gpm out.
 

RhettMan

LawnSite Gold Member
Location
Texas
activated full, 1.25 hrs drawn down, followed by, say 1.5 hour refill)

maybe better to run just 1 hour keeping the intake a little higher off the bottom to allow for debris seperation?

I suppose it comes down to how large an area/ how many zones.

Only so large an area fits into "nighttime hours", and then only so large an area fits into a watering interval/etc.

for a given source, i mean.
 

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