During my time at Colorado State University in the late 1970s, I had the pleasure of casual interactions with Prof. Vujica Yevjevich,¹ a man of many talents. At that time, he was in charge of the Civil Engineering Department's graduate Hydrology Program, while Prof. Daryl Simons was head of the Hydraulics Program. Many students who graduated in these programs now lead the development of hydrology and hydraulics around the world.

Prof. Yevjevich had a good sense of humor. Once he told a group of students that, judging by his own experience, if you were a hydraulics person, your progeny was going to be male; conversely, if you were a hydrology person, it was going to be female. For proof, he simply stated that he had three girls, while Simons was the father of three boys. Following this reasoning, if you work in both fields, as many civil engineers do, your progeny will be mixed. It did not take me too long to figure out that this was my case: I have a son and a daughter.

The Yevjevich progeny rule may not always apply; the exceptions confirm the rule. But one thing is for sure: it is a good tale. I wonder if it has something to do with hunting and gathering, the proverbial genetic traits of male and female. Hydraulics may be more in tune with hunting, while hydrology resembles gathering.

Is this hydraulics or hydrology?