Man, you're in a pickle. Any chance you could just get a dozer and push a secondary road around the non dam end of your pond to where you need to be? You can possibly get 150 yards out of a good strong line pump but that's absolute max distance and you're going to have to run a really high slump on your mud to be able to flow it that distance. It's going basically be self leveling concrete at that point. What exactly are you trying to pour? How many yards are you needing for the pour?