what could be reason for water in boot and rear footwells on 2001 Toyota 4Runner

I dont know where the water is coming from have checked seals and upper areas of car are dry the amount of water is excessive all the carpets and felt padding is saturated

Asked by for the 2001 Toyota 4Runner
Boot??...have a helper with a water hose spray the vehicle while you watch from inside with a flashlight for leaks..... doors and windows closed!..