Can I just empty water tanks instead of winterizing?

What type of RV do you have?

My experience is with Truck Campers (Lance and Outfitter), fairly cold winters down to the singe (Fahrenheit) digits.

The fresh water tank has a low point drain valve. Turn off water pump, open all faucets, open low point drain(s) and let out all the fresh water.
Empty the water heater (remove drain screw).
Empty the gray and black water tanks. Might be a good idea to flush them while you are at it.

No antifreeze here. Basically unheard of for winterizing RVs over here in Germany.

Worked for me without any problems through near 0F winters.

juggledog wrote:
I live in Portland, where the average lows don't usually go below freezing, but you never know.

In regards to winterizing, can't I just empty the water heater tank and fresh water tanks and leave it at that? Why do I need to put antifreeze in it? Since it doesn't get too cold where I live, can I get away with doing this?

I've never winterized before, and I'd like to avoid doing it if possible.

Empty tanks won't be damaged, most damage occurs in small pipes, pumps etc.