Fresh water tank drain

[Hankp]

Hello all, there is a red and blue drain pipe with valves in the water compartment out side, that go through the compartment floor. Do these drain the fresh water tank or just the water lines to the sink etc. I assume it’s for winter prep. I wish to drain the freshwater any suggestions. Thank you
Hank , 2020 High Country in SoCal

[jsb5717]

The red and blue pipes in the side water bay drain the plumbing system throughout the trailer. Our fresh water drain is a single pipe with valve sticking straight down under the rear of the trailer.