As more rooftops start to double as farms and towers become artificial forests, it's clear that hybrid objects, those that are part manmade and part natural, are a hallmark of 21st century design. Engineered Nature, a five-part series by Karrie Jacobs, explores the emergence of this new hybrid world, from a sensor-packed hill in the New York Harbor to manmade rivers in East Texas. Unless you?re a water-park enthusiast from East Texas, the name Jeff Henry probably doesn?t mean much to you. Or it wouldn?t have until early August, when a Kansas City water slide he designed with the all-too-accurate name Verruckt (German for insane), the world?s tallest at 168 feet, took the life of a 10-year-old boy.
An in-depth Kansas City Star report on the accident asked whether the ride had been "too much, too fast." A reasonable question. Reportedly, Henry cooked up the giant slide on the spot at an event to impress the producers of a Travel Channel show called Xtreme Waterparks. Personally, I think it?s a shame that this is the ride that?s introduced the man to the general public, because Verruckt and all the other jumbo slides and water coasters that are now an intensely hyped feature of the water park landscape are a diversion from Henry?s true calling. He?s not a builder of thrill rides, but a builder of rivers.

Now 61, Henry has spent most of his life constructing artificial rivers, primarily for the pleasure of the two million annual visitors to his...