I an tentatively planning to use multiple booster pumps to provide irrigation and fire fighting capability. We have a small farm with orchards and row crops, and a very old well that is not as strong as it once was. I've installed tanks to store water through the day and night so I can irrigate in the early morning and not run the well dry.

I have a 2 1/2 inch line from the tanks to a 1 hp booster pump feeding into 1 inch lines that go off to the house and various irrigation lines. I want to add a fire hose hydrant, and use the oputput of the existing pump plus an additional pump or pumps in parallel with the existing pump to get the flow and pressure I need for fighting grass fires. The pumps and tanks are in a reasonably fire-proof structure (masonry walls with metal roof and underground electric feed), and it has a gas-powered generator inside it to supply power during our frequent power outages.

I figure I can either install pressure switches that will turn on the additional pump when flow is high or just install a manual switch next to the hydrant. I would size the additional pump or pumps (I like redundancy) to the flow limit of the 2 1/2 inch line.

So my questions are, does this sound like a good idea, and where can I find information about designing such a system? I like it because it is cheaper than buying a single fire pump, requires minimal changes to my existing setup, and gives me built-in redundancy for irrigation. If a booster pump goes out, I already have an installed spare.

I'd appreciate your advice.

What is a pommfarmer? Is it a spudmeister? The only question I have in your logic and desire to keep cost down is, can you get full flow and pressure if a fire starts and you are filling your tanks? If you do, no problem that I can deduce. If your answer is no, then you need an isolation valve or a bypass line at the tank to give full flow and pressure when you have a fire. That is usually why there are separate system for fire protection. JMHO Aloha