"A shallow well jet pump can pull water from a maximum of 25’ depth-to-water. Note that it may be less in higher altitudes. In the mountains it could be as little as 18’ to 20’."
Altitudes in British Columbia:
Altitude might be a factor here, and your description of that overall situation reminds me of customers or employers in my own time who wanted things that were just not going to work well, if at all...and all those "burned out pumps and pressure switches collected in the back of the pumphouse" seem to confirm that in this case also. The presence of that large tank makes me suspicious that two pumps used to be present with one to keep the tank full and another to draw from there for wherever the water needs to go, but then one pump or the other gave out and somebody decided to downgrade the system.My question is, am I asking this sprinkler pump to do something it was never designed for?