Man-Made House Flood

Sometimes a member of the family, a housesitter hired to watch the house, or even both, end up doing something so stupid that it results in the house (usually ground floor) being flooded to the knees of an adult. It's commonly a source of comedy. Bonus points if they don't show how they did it, and it starts with a phone call focusing on the face of the caller before panning back to reveal the flood.

Examples of Man-Made House Flood include:

Film

In Home Alone, the Wet Bandits (or rather, Marv) deliberately invoke the trope when robbing houses as a Calling Card. Said action ends up biting them in the butt in the climax where they are arrested for every single house they robbed.
A variation happens in Jumanji, when playing the game causes a monsoon inside the house.

Live Action TV

Happens in an episode of The Drew Carey Show. Drew has a crush on a (female) plumber, and punctures a pipe so he can call her and get her to come round to his house.

Newspaper Comics

Calvin and Hobbes had Calvin calling his dad at work, apparently to make small talk. The final panel reveals the real reason he's calling: He somehow managed to flood the house, and the waterline is high enough to reach the top of the stool that Calvin is currently on. The next strip references this event, where Calvin's father retorts angrily after Calvin gives him the poll results of his "reign" as dad, revealing that the reason he took away dessert from Calvin is that Calvin flooded the house.
- In another, Calvin turns the stairs into a waterfall.
In FoxTrot, during the time where Roger has to housesit for Andy while she's out of town, Roger is calling her reporting what's going on at the house, and wonders when she's going to be back. The final panel reveals that he is waist-deep in a flooded kitchen; Jason remarks that even he knew how to properly operate the dishwasher (implying that Roger messed up so badly on the dishwasher that it resulted in the flood). They eventually got rid of the flood before Andy gets back, although not without having to contend with a swamp.

Western Animation

In The Simpsons episode where Lisa has to contend with being the authority figure of the house when Marge ended up injured from a clock falling on her, Lisa is calling Marge, and it's revealed after briefly talking to Marge that Lisa is currently on a stool in a flooded house, with Homer and Bart playing Marco Polo. It's strongly implied that Bart and Homer caused the flood.
- Homer did a variation in the beginning of one episode, where the entire house was covered in waterfalls before running out of the house to go to Moes, although in this case, we actually see how he did it: After the kids were unable to take a bath due to the water heater being broken, Homer attempts to fix it with a crowbar, thus causing the water heater to explode in a geyser.