WaterUse
The class of s4watr:WaterUse is populated by a set of instances. Many occurrences of such as pattern are found in other extensions. This could be a candidate for defining a pattern where skos:Concept and skos:ConceptScheme may be used.
(Not sure anything needs to be changed in SAREF4WATR, but this issue records the fact that SAREF4WATR was mentioned in the referred issue)