The title is a play on the phrase "wet hair."
Bugs Bunny is taking his morning shower under a waterfall, singing "April Showers" (à lá Al Jolson) when the water stops flowing. After briefly worrying that the supply has permanently dried up, he decides that beavers are responsible, and climbs up the waterfall to the source of the problem. The "beavers" turn out to be the villainous Blacque Jacque Shellacque, who has built an illegal rock dam in an effort to control the water supply and sell it at inflated prices. Bugs asks Jacque what would happen if certain rocks become loose, to which Jacque simply states he would replace them. Jacque laughs off removing a tiny rock, but it dislodges the dam.
Later, Bugs resumes showering, but Jacque has built a replacement dam ("This time I build him stronger!"). Jacque expects another sabotage attempt from Bugs, and thinks he's still one step ahead of the rabbit when he spots what he believes to be a phony shark fin in the impounded water. The shark is real, however, and Bugs "saves" Jacque by crashing a log through the dam ("This is being saved??").
Still later, Bugs has resumed showering again, but Jacque has built an even bigger replacement dam, and gloats at Bugs from above. Unintimidated, Bugs turns to the audience and quotes Red Skelton's "mean widdle kid": "He don't know me vewy well, do he?". Bugs then sends a lighted stick of dynamite towards the new Shellacque-built dam, but as Jacque tends to it (or vice-versa, as the dynamite blows up in Jacque's face off-screen), he doesn't immediately notice a huge raft full of lighted dynamite subsequently headed toward the dam.
Finally fed up with Bugs, Jacque fires his rifle into the waterfall, thinking he's killed off his nemesis once and for all ("So much for crazy seec rabbets! Bah!"). Nearby, Bugs - watering his carrot garden - sees that his record player has been destroyed by Jacque. Although mad at first, Bugs calmly declares his time-honored, Groucho Marx-inspired warning: "Of course you know, this means war."
Later, a triumphant Jacque boasts about his new steel dam, but quickly finds his water supply has been cut off. Bugs, it turns out, has turned the tables and built a dam of his own. An angry Jacque retrieves a cannon and blows the dam apart, only to find another rabbit-built dam. Jacque blows that one up as well, only to find more dams until he finally reaches the Grand Cooler Dam. Jacque tries to blow that dam up as, well, but the attempt fails and he is arrested by the federal authorities. "He's not foolin' me. He'll be back..." says Bugs as he watches his nemesis being taken away. "Like, uh, in about 20 years?"
Wet Hare at SuperCartoons.net