Hello,
If the pigs have ben using it recently, and it simply dried up, you may be able to "freshen it up" by simply bringing in the water. If it is on a powerline, it should be fairly easy to access with a truck or ATV. I have hauled water in a 55 gallon drum for many reasons, and this has been one of them. Years ago, we found a spot where some piney wood rooters had been hanging out in a huge cutover thicket. No way to stalk in on them, so we found a good spot nearby and created us a mud hole. It was not long until the pigs found it and obviously loved it. I never took a pig from there but the guys who lived nearest to it did. If you were to keep it wet, I am sure that the pigs would appreciate it and oblige you with a visit. Maybe you could set up and wait them out, or better yet, set a trail cam to pattern them so you could see the times they are most frequently there. Just a different angle from a hard core pig hunter.Good luck and God Bless You All.
Dave