I see what you're saying and agree. If there's readily available water, then why pack that heavy stuff. I was assuming, since they appeared to be quite dehydrated, that perhaps the lake water was undrinkable. Maybe they just didn't know to hydrate regularly? Sounds like a combination of heat and dehydration did them in.

HJ

If those guy's had seen that episode of, Bear Grylls giving himself an Enema with Very fouled,fowled water,they more than likely would have concluded,You can pack water,& Enjoy it or You can fudge pack water,& probably Not enjoy it!