When you live in a neighbourhood with a name that includes the word "lakes", you need a reliable sump pump. Ours goes off whenever it starts to rain and will continue discharging for a few hours after it stops raining.
This morning, my backup sump pump saved the basement; it was beeping because
the primary pump's screws had finally rusted away and the pump was heating up
the sump water, drawing 7 kW of power!
I turned it all off and installed the spare sump pump. The pump manual
says to drill a 3/16" hole in the pipe to prevent vapour lock when the pump
stops. Well water comes shooting out at high pressure, so I improvised a water
deflector which some rubber.
When you have a backup pump, both pumps must be connected with a one-way valve,
otherwise the water will never be pumped out.