1999 Jayco Eagle 283G Class C

[dcrump]

Hello Everyone,
Just purchased my first used Class C, its a 1999 Jayco Eagle 283G Class C mini motor home. It has 26317 miles on it and is in really good shape.
I am winterizing it using the utility center. I have all original manuals but I cannot locate the water storage tank and its drain as described in the owners manual. I drained the two low point drains at the utility center and pumped rv antifreeze into the lines. I have been all under and in the coach and I cannot see the water storage tank. Found the black tank and drained it. Can anyone assist me in where the water tank is located and its drain valve?
Before winterizing I tried loading water into the tank to flush it out. Not sure what I am doing but I discovered three clear tubes from floor at the dual tires left hand side had water flowing out of them when I moved the utility valve to fill tank. Assumed they may be tank overflows.
Dealers can't tell me about the water storage tank, its location and its drain, they say because of its age.
Any help is greatly appreciated.
Thanks,
DC