Almost 80% of all water consumption comes from two groups: No. 1, thermoelectric power, and No. 2, irrigation (farming). Public supply, which includes industrial buildings, commercial buildings and residences, accounts for only 10%.

In 2012, the International Association of Plumbing and Mechanical Officials (IAPMO), the University of Cincinnati (U of C), and the American Society of Plumbing Engineers (ASPE) began to work on a new sizing technique 80 years in the making. The main drivers were Dan Cole (IAPMO) and Steve Buchberger (U of C), and later Toju Omaghomi (U of C). As part of this effort, hundreds of thousands of data points were taken and evaluated to determine actual human behavior and plumbing fixture use in residential homes.

It hasn’t taken long for some of the most obvious unintended consequences to appear: More people are complaining that their shower experience is deteriorating due to lower flow rates, and shower times are increasing as people have to shower longer to wash the shampoo out of their hair.

In creating Hunter’s Curve, the beauty of what Dr. Roy Hunter did was to take an incredibly complex problem in probability theory and make it simple — so simple, in fact, that all it required was basic arithmetic.