“为水淹没”可以翻译为“be submerged by water” 或者 “be inundated by water” 。
“submerge” 强调被水完全覆盖、浸没在水中 ，例如：The low-lying areas were submerged by water after the heavy rain.（大雨过后，低洼地区被水淹没了。）
“inundate” 同样有被水大量淹没、泛滥成灾的意思，如：The entire village was inundated by water during the flood.（洪水期间，整个村庄都被水淹没了 。 ）