Sprinkler booster pump

[Steve B]

I live where we have both agricultural water and potable water. In the winter, the ag water boosters are turned off, but the line still provides water at very low pressure. I believe I can put a booster pump on it, and it will provide enough water so I can run my timers and sprinkler system during the winter instead of dragging my little booster pump and the back-and-forth sprinkler all over. I believe I would need a pump that will attach to my 1" supply line, and provide 50 psi coming out, what my normal ag water pressure is during summer. Is this what is typically done in the off season? I saw one fellow running the big Rain Birds with 2" lines, and spraying 100'. I'm sure he has a booster, because the whole valley's ag water comes from the same place. This is only needed once a month or so during the winter months, and helps the grass survive in better condition come spring. Pump brands and types suggestions appreciated, and caveats. I'm guessing about $150 for a pump.

TIA

Steve

[DD_BobK]

Steve-

Adding a booster pump to "inactive" ag line will definitely give you a boost in pressure but........ The flow (gpm) supplied by the ag line is all your booster pump has to work with.

Do a "bucket test" to see what the inactive ag line can supply, that will be (more or less) the flow that your booster pump has to work with.

The booster pump you add will boost the pressure deliverable to your sprinkler lines but the flow may be inadequate. I'm guessing you'll have less than 10 gpm to work with.

The guy running a 2" line off his booster pump must have a much larger supply line to it.

cheers Bob

[trader4]

Agree with the above. If you have sufficient water flow any number of shallow well pumps will work as a booster. The exact choice would depend on the flow rate and pressure needed.

[DD_BobK]

Steve-

I just had a thought that might be helpful in this situation.......

The inactive ag line could be thought of similarly to a very low capacity well.

Suppose someone has a very poorly performing well. The well pump runs & then shuts off because the aquifer has been drawn down. The aquifer recharges & the pump cycles again. The pump runs at 20 gpm but only for 1 minute, six times per hour, thus showing that the well is only capable of a sustained delivery of 2 gpm. Not every much flow to work with. :(

But over a 24 hour period the well can supply 2880 gallons!

My point is.... you could fill a plastic ag tank over a reasonable amount of time and then use the water collected in the ag tank to supply your booster pump.

All you need to do is determine the sprinkler flow required for each of the lawn zones (or the total of all zones if you want to run all at once). Armed with the gpm required to run the sprinkler system and an idea of how long you;d want to run them, you can determine how large an ag tank you'd need.

Another way to figure it is, gallons per square foot x lawn square footage. I believe a recommended lane water application rate is ~1/2"per watering session which works out to about .31 gallons per square ft. A 1000 sq ft lawn would need about 300 gallons per watering session.

You can play with these numbers, factoring them according to your lawn size and the amount of "rain" you want to simulate. My number is for 1/2" of rain but you might want a bit more or less.

In any case, it looks like an ag tank of ~500 to 1000 gallons would easily service about 1000 to 2000 sq ft of lawn.

What is the flow rate of the inactive ag line? At 2 gpm you'd only have to "collect" water for 2.5 hours, even less if the ag line flow more.

Here's a water tank

a bit big a bit small

cheers Bob