I never considered that, but I'll definitely need to keep it in mind for the future!
My mind went straight to valves when I started planning, plus I didn’t know that they even made pumps that worked in both directions. Thinking about it quickly, it certainly seems like it would work for tank-to-monitor and draft-to-tank, but I don’t think it would work for the third option I want, which is draft-to-monitor. Plus at this point, I already have the pump and 2 of the 3 solenoid valves I need, so it will only cost $8 for the third valve.
Here's what I'm planning:
I’ve only bench tested a few parts of the system, not the entire configuration yet. Based on the testing, it seems my biggest challenge will be getting a realistic flow of water out of the ½” square dump chute. Going thru the pump only provides a small stream, so I either need to try a ½” solenoid valve or try building my own servo actuated dump valve.