This may not be a new idea. We implimented a program with the help of our city water department to save some money on our water usage. A large percentile of the water going to a CT is evaporated. Because of this we felt we shouldn't have to pay sewer charges levied by our city water department on the water to the CT's and our city water department agreed. We placed meters in the incoming water and on the bleed off to determine where we were and after settling on a figure of 5% on the bleed off we began the program. We saved thousands the first year because of the very heavy design load days. Cost of the meters? We had two already laying around for the bleed off and we purchased two remote read meters from the city for the supply lines for about $500. Payback was immediate and impactful. Check it out. Even if you have to pay a plumber (We did this in house) it's still a very quick ROI.
Thats a good idea. Thanks for reminding.