Current Web Engineering methods develop "closed" web applications. This fact makes difficult the integration and the interoperability of different web applications. Semantic web languages provide an appropriate framework to achieve these non-functional requirements. Ontologies are proliferating to enable interoperability between Internet-connected applications. This work takes advantage from the navigational model enriching the web implementations with all the knowledge gathered during the modeling and design process. Our approach provides a semantic representation of web applications in the form of a navigational ontology that can be queried through the use of a semantic query language.