Greeting from Southern California:
I am interested in extracting water from a water table that is less than 15' deep. I know the depth of the water table as I recently dug a trench to install a sewer pipe. There was so much water that we needed to de-water the trench with a pump to install the line. We were pumping approx 45 gallons per minute (or 170 liters/min)
I suppose that I can get the irrigation water the same way by digging a trench filling it with rock and submersing a pump, but I am not sure if this is really the best practice.

Would appreciate your feedback.

Thanks