This is the 8947th most frequent Japanese word.
水域
"水域" (suiiki) means "water area" or "aquatic area."
General reference to a water area (lake) as an ecosystem.
湖は様々な動植物が生息する水域です。
The lake is a water area where various plants and animals inhabit.
Specific area of a river defined for regulatory purposes.
川の水域には釣り禁止の看板があります。
There are signs prohibiting fishing in the river's water area.
A coastal water area mentioned in the context of tourism attraction.