Dehydration was not the intent, it was supposed to be just a long desert hike:

"I thought, I’m pretty tough. I can do that," Broyles says. He planned ahead and buried water caches at strategic points of the journey, which he described in a 1982 article. "Intending to parallel [Valencia’s] route, I had no design to parallel his plight," he wrote. "But the desert doesn’t always honor human plans."