This paper takes on a huge challenge in trying to formalize GIS hydrographic data for semantic technology by developing an ontology for surface water. One issue it covers is how “surface water features have physical qualities that can lead to socially defined functions and roles” (Sinha et al 2014). The authors address this in part by creating the :Function class, “with criteria that if a particular feature bearing a quality, role, disposition, or function is removed, the feature may be changed, but continues to exist” (Sinha et al 2014). This seems to be a reasonable way to address what should happen to a feature whose use is discontinued; however, the paper does not mention a class that addresses what happens when a feature’s function is changed but not removed. For example, how would this ontology account for a former hydro dam that’s now used as a bridge? There are many important questions that the paper fails to address with respect to a feature’s “socially defined functions and roles.” How can less obvious instances of such functions and their impacts be determined? For example, how many people fishing in certain areas of a river would it take to affect its flow rate? What are the impact of non-human uses of water bodies, like a beaver building a dam? What features of the river, classified in this extensive ontology, are associated with certain usages (for example, a slow flow rate or a wide river bed)? The authors have created quite a thorough ontology with respect to certain human uses, such as bridges, canals, gates, and levees; however, the more nuanced considerations outlined above appear to be underdeveloped and could be built upon in future work.