Flood Damage
Water Damage
noun
Water damage is so bad they call it water damage. Doesn't get any clearer than this.
This is a jukugo word, which usually means on'yomi readings from the kanji. If you know the readings of your kanji you'll know how to read this as well.
地元が水害で大変なことになっているようだ。
It seems that my hometown is in serious trouble due to flooding.
私は、水害の起きやすい島で育ちました。
I grew up on a flood-prone island.
その水害で、5,000匹の猫が家を失いました。
The flood left 5,000 cats homeless.