Two-way coupled systems have been studied extensively and are well understood. One-way coupled systems have only been studied in the past five years, mostly through theoretical or computational work. These systems at first glance seem impossible, as they appear to violate both Newton's Third Law and energy conservation. Nonetheless, we have built a mechanical one-way coupled array that is powered by falling water. This array displays the propagation of solitary waves known as solitons, a defining feature of one-way coupled systems. The dynamics of the mechanical array has been analyzed and compares well to the theoretical and computational predictions.