To elaborate a little, the "hookup" provides the pressure your water system needs in the water lines them selves to operate the system without the need of filling the 80-gal fresh water tank. (Sorry, I can't get rid of this underling). Should you, however, need to have water, without hookups, it may take a few minutes to fill your 80-gal fresh water tank. Strongly recommend, when you fill the 80-gal tank, to have someone monitor the level of the water in that tank to preclude overfilling.
'16 JAYCO 154BH SLX, Baja Ed
'13 Silverado 1500LT, 4WD, Ext. Cab, 5.3 ltr.,LNG BD
"Fair Winds and Following Seas"