Calvas River From Wikipedia, the free encyclopedia River of Ecuador Calvas RiverLocationCountryEcuador The Calvas River is a river of Ecuador. List of rivers of Ecuador References Rand McNally, The New International Atlas, 1993. GEOnet Names Server Archived 2020-04-10 at the Wayback Machine Water Resources Assessment of Ecuador This article related to a river in Ecuador is a stub. You can help Wikipedia by adding missing information.vte Related Articles~TimelinesTop QsFact Checks