We can't really access the water in the tank, but we have a workaround, which is a 4" hose end cap with a normal faucet brazed on that we stick on the drain valve. Works perfectly.

Cut off in our case means that we are somehow
a) out of the supply chain and
b) not able to go someplece that is still getting deliveries.

An example would be what happened last month: A dam broke, and the only acccess road to where we were flooded five feet deep. We were on high ground, the water didn't touch us. As we were in a village with people left, we were still working our rear ends off till we ran out of sandbags.

Weather can be anything, though usually no snow or hail. We've seen blazing sunshine and 100°F, and ten degrees above freezing with driving rain.

About energy expediture for hunting: With the levee setups here at the Elbe, huge tracts of (mainly empty) land are flooded intentionally to relieve pressure on important levees downstream. This should confuse and drive together the animal population, so actually finding them is no problem. We had bewildered rabbits running around our feet in 2002. If we have the room and weight for a 7-day kit, it's fine. If it turns out we haven't, it's probably time to go hunting.

Storing supplies in the cab of the engine could be possible, but that space is pretty much reserved for personal items such as clothes and the bassmachine (music is still the best motivator when sandbagging)