So Texas won’t provide potable water to the inmates through the tap system:

“I would never drink the water at the tap,” said Don Aldaco, a recently paroled man who spent 24 years in various TDCJ facilities. “I would always get a piece of a sheet and I would tie it on the actual spigot, like a filter. I would have to change it like every other day because of all the rust and all the crud coming out.
Other current inmates commented on the smell of tap water in specific facilities resembling sewage. A TDCJ spokeswoman called the claim false.
“I actually begged him not to [drink the tap water],” said Amy Aguilar, whose loved one is at TDCJ’s Ferguson Unit. Her significant other — whose name she asked TPR to not use — has described the water as “rancid” smelling. And she said she was concerned about the quality.
“Do you smell the sewer?” Aguilar said she asked him, “And he goes, ‘you kind of just smell it all. It’s just this big ole rich mix of rancid smell.’ ”
Water quality in prisons nationwide have been characterized as very low, due to the age of the facilities and the often remote locations.

…forcing the inmates to buy water to survive, and then, compounding their negligence, lies about the price increases in the middle of a heat wave:

TDCJ initially told TPR it had nothing to do with the price change. It added that the negotiation falls completely on the comptroller, and it did what it could to blunt the impact. The prices approved in April went up in late June.
“Due to the increase, TDCJ held the price at a lower cost for a few months as it went through our internal processes and to delay the impact felt by the inmates for as long as we could,” said Amanda Hernandez, director of communications for TDCJ.
A comptroller spokesman said the description was false, and that the price rise was done in concert with the state prison system — and released emails that appear to back up the statement.
“We approve the increase for the remainder of the contract,” wrote Tanya Hudnell, director of contracts and procurement for TDCJ, in an April 11 email to the comptroller’s office, who requested their sign off.
The prices may seem negligible to the working world — as a single bottle goes from $.20 to $.30.
“For people who are receiving absolutely zero pay for their work, any increase in cost is extremely significant for them,” Deitch said.

…resulting in those with no savings or outside help having to drink sewage tainted water in order to survive.

This would be a violation of the Geneva convention if they were enemy soldiers, and this is an absurd cruelty. Here’s an action link for the Texas Center for Justice and Equity if you feel the same way.