Air conditioning leak on 2009 Buick Lucerne

Apparently my ac drain is leaking into my passenger side rear floor board. Really a lot of water. Any ideas?

Asked by for the 2009 Buick Lucerne
Yes, the drain hose is plugged up, it is under the right hand side of the vehicle just under the passenger floor area. I usually take a coat hanger and then use the wire to make a stiff tool to unblock the drain hose.
thanks a bunch. I'm going to do that at first light!