The property didn't notify the water stop in advance, and the child forgot to turn it off after turning on the tap, resulting in flooding at home. Who is in charge?

First of all, it depends on the water supply company or the property. If it's the water supply company, it depends on whether the water supply company has issued a notice to stop water supply. . . The obligation to inform the property is only to inform in advance. . .

Secondly, it is an adult's supervision problem that children forget to turn off the tap. . .

Finally, unless it is proved that the property was obviously at fault in the process of flooding (for example, your home was flooded, and the property was not found or taken measures in time, causing losses to a third party, and the third party may require the property to bear joint liability), the property will not be liable. .