Unfortunately I have first hand experience in this--I had to leave my place in about 15 minutes when it flooded late last year. I quickly moved a few valuables to high ground (SLR camera), packed some clothes in a bag, grabbed my passport, birth certificate, home insurance and HOA info, point and shoot camera, and phone charger. Killed the power and got out just as about 2 inches or rapidly rising water had filled the whole place. Not a fun night--I still haven't been able to move back in 5 months later.