Early in my career I was taught how to do a water balance (WB) when addressing industrial water and wastewater challenges. The WB process allows the engineer, or designer to know all the important factors that affect a new water system design.
The process takes into consideration total water supply and examines other input factors such as how quickly does the water supply replenish itself; in other words, how sustainable is the supply. Furthermore the WB takes into consideration the maximum pumping out flow rate, water quality (specific analysis of all contaminants), temperature and seasonal changes, and even potential contamination threats. Once that is all completed, a proper water system can be designed.
Sadly, when we look at how man is addressing the global water crisis, we really are not doing a water balance. How many residents can a water supply support? How will new jobs and residents impact the water and wastewater system. What increased contamination risks do new residents and manufacturers represent. The list goes on and I venture to say that very few municipalities have ever completed a water balance. Instead, we continue to migrate, build and expand our presence without ever stopping to think, can the local water supply meet all these new consumers?