This is the 10604th most frequent Russian word.
водами
"Водами" means "waters" (instrumental or prepositional plural form of "вода").
The word "водами" is used as an instrumental plural form of "воды", meaning "waters", indicating the entity in the context of being surrounded.
Океан окружен водами разных оттенков синего.
The ocean is surrounded by waters of different shades of blue.
Here, "водами" is instrumental plural, indicating the agent (the rivers' waters) that performed the action of washing the mountains.
Горы омывались чистыми водами рек.
The mountains were washed by the clean waters of the rivers.
The word "водами" is used in the instrumental plural, referring to the waters of the lake over which the bridge stood.