Most water meters register in cubic feet and show the GPM rate. Why cant you get a Badger Meter or any of a dozen other brands and go to a common header?
If you have low and high volume demands then look for a compound meter.
Off this header you could have tees connected to a solenoid valve off the bull of each tee.
Then all the operator had to do is either flip a switch or push a button to energize the valve SAME principle as a hydronic system with 20 or 30 zone valves
SylvanLMP