Welcome to the forum.
Not overly familiar with the X210 but on my XT 276 the drain valve is located on the bottom of the fresh water tank. Look under your camper, see the fresh water tank and the valve will be on the bottom of the tank. Mine is white in color with a side lever to turn it open/closed. Hope this helps.
STAY SAFE during the storm. ... could be bad.
2012 Fun Finder XT 276 Toy Hauler & Harley Davidson Ultra Classic with Condor wheel chock
2014 Dodge Ram 2500 AT 4X4 Crew Cab 6.4 L Hemi, 373 gears, tow package, Rambox option, Revolver X2 tonneau cover, Equal-I-zer anti-sway hitch.