Sizing an Electric Irrigation Pump for 3-Acre Sloped Farm with Stream Source

Selecting a pump for 3 acres of vegetables on shallow soil (4" to rock), 2000 ft from a stream, 200 ft elevation gain, requires careful hydraulic calculation—not just matching old gas-engine specs.

Critical Missing Data

• Pipe size for the 2000 ft run (determines friction loss)
• Peak GPM demand (crop type, emitter/head spacing, simultaneity)
• Stream flow rate at pump intake (must exceed peak demand)
• Suction lift (pump above stream? by how much?)
• Power availability (single-phase 240V? 3-phase? amperage?)

Why Old Specs Don't Translate

A gas engine with 280 ft head / 250 GPM / 7 HP implies a specific pump curve. Electric motors have different torque curves. "400 ft head" at what flow? TDH = elevation + friction + pressure. At 2000 ft, friction in 2" pipe at 100 GPM = ~100 ft alone.

Next Steps

1. Measure or estimate peak irrigation GPM.
2. Determine pipe diameter (existing or planned).
3. Confirm electrical service at pump site.
4. Contact a pump supplier (Grundfos, Franklin, Berkeley) with complete data for sizing.

Don't guess. Undersized pipe or pump = crop failure. Oversized = wasted capital and energy.