The rise of the ecosystem services concept has brought some characteristics of the water cycle to the attention of a broader audience who are not necessarily intrinsically familiar with hydrological processes. When referring to water supply, the term “hydrological regulation” (or streamflow buffering) is frequently used by non-hydrologists, yet they are often lost in the intricacies of the processes that drive it leading to confusion and misunderstandings. It is not uncommon that several water security challenges that require the conservation or enhancement of hydrological regulation end up prioritizing actions that aim at increasing water yield instead. Here, I present a simple index named “baseflow yield coefficient” (BYC), which is calculated as the ratio between baseflow (or dry season flow) and precipitation for a given period of time. Although quite simple, this might be a powerful tool to quantify both water yield and hydrological regulation and to provide an accessible and transparent variable that addresses the aforementioned issue. By using this index, I aim to guide the conversation to achieving more effective water security investments while, at the same time, seek to prevent having to revive the misunderstanding between water yield and hydrological regulation, so that we can move directly on to more relevant matters.