This is the around the long way method, but it’ll start you on a crippling hobby to instrument your entire life.

Raspberry Pi home assistant zigbee USB zigbee water sensor.

you could stop here at notifications.

or

Descend into madness, put a small ac submersible pump into your dehumidifier tray with a smart outlet. When the sensor trips full, have it run the submersible pump for x minutes.