Well Pump vs. Booster Pump

If you're on well water, your irrigation pump situation is a whole different ball game compared to city water. I've set up hundreds of well-fed irrigation systems, and the key is understanding how your well and domestic systems interact.

The Fundamental Difference

• Booster pump: Takes water that's already pressurized (from city supply or a well pressure tank) and increases the pressure further.
• Well pump: Pulls water from underground. It IS the pressure source. Your submersible or jet pump is what creates water pressure in the first place.

Using Your Existing Well Pump for Irrigation

Can you? Maybe. Here's what to consider:

1. Well yield: How many GPM can your well produce sustainably? If your well tests at 8 GPM and your house uses 3 GPM during irrigation, you only have 5 GPM for sprinklers.
2. Pressure tank size: Small tanks cause the well pump to cycle on and off rapidly during irrigation, which burns out the pump motor.
3. Recovery rate: If you drain your well during a long irrigation cycle, you could run your house dry too.

When to Add a Separate Irrigation Pump

• Your well yield is limited and you need to share between domestic and irrigation
• You have a surface water source (pond, lake, stream) you want to use
• Your well pump can't maintain adequate pressure during irrigation
• You want to keep irrigation completely separate from your domestic water supply

Dedicated Irrigation Well

For properties with high water needs — think large lawns, multiple garden beds, or anything commercial — I often recommend drilling a dedicated irrigation well. It costs $3,000-8,000 depending on depth and location, but it:

• Eliminates competition with your domestic water
• Can be sized specifically for irrigation demand
• Reduces wear on your domestic well pump
• Often has fewer restrictions than municipal water for outdoor use

The Pressure Tank Question

If you're using your existing well pump, consider upgrading to a larger pressure tank (80+ gallons). This gives the pump a buffer so it's not cycling every time a zone kicks on. A cycling pump runs hot and dies young.

My Bottom Line

If your well produces at least 15 GPM and you have a properly sized pressure tank, you can usually run irrigation off your domestic well with a booster pump to maintain consistent pressure. Below that, consider a separate system.