Riparious is an unusual word, and there aren't many synonyms that come to mind. However, some possible alternatives may include "riverside," "streamside," "bankside," or "riparian." These words all describe areas near a river or body of water, and may emphasize the proximity to water over other characteristics of the location. Other options could include terms like "shoreline," "waterfront," or even "wetland." Ultimately, the best synonym for riparious will depend on the context of the situation and the intended meaning, as well as the writer or speaker's preference for certain words or phrases.