That is just one of the many problems in the New Dark Ages. There will be no running water, no electricity or similar energy delivery systems, no communications systems, no waste removal systems of any kind--no nothing. Everyone is trained solely to do field circus, to miseducate everyone about the Unholy Bible (and nothing else). And, anyone that is smart enough to develop new infrastructures or to solve these problems is smart enough to become apostate, and God is going to destroy them for apostasy.
And it will stay that way forever. No one that is intelligent enough to solve any of the problems will survive, because they will start questioning Jehovah's right to absolutely control everyone and have to die for that. Of course, we all know what Jehovah's answer to Him solving our problems is: "As long as I do not have to live with it, I don't give a f*** about solving it myself."