Have you looked into a PTO driven pump? Does anybody on the forum have experience with one of these? Way back when I was in high school we got to take 2 weeks off school to do what we called "senior project". You volunteered at a hospital, school, state park..etc. I worked with the the conservation guys at a local power plant lake. One day we when out to fill a growout pond (1/2 acre?)that was alongside the main lake. They backed a PTO driven pump into the lake and ran a hose to the pond. It was over 15 years ago but what I remember is that we were able to fill the pond in one day. The hose was over 18 inches wide and shot water several feet out. It was a good sized JD tractor running it (4010 maybe) but I was amazed at the amount of water it could move. I would guess this type of pump is best used to move lots of water a short distance. You might want to look into seeing if this type of pump is available for rent locally provided you have a tractor to run it.

Does the name Pavlov ring a bell?