See if you can rent a tree dolly. They are very heavy duty and can lift hundreds of pounds. You just push the boulder onto the dolly, then can maneuver into place.

Here is a link that might be useful: tree dolly

I'm sure it's too late but I would use chains and come-alongs staked firmly into the ground or tied to trees uphill from the pond. If you use two to balance the load, you can release the come-alongs one chain link at a time on both of them and move the rocks very slowly into the pond. We moved a 20 ton piece of equipment all over a concrete floor using only two pretty small come-alongs, chains and a few rollers.

Or if the question is how to move them toward the pond, mount the come-alongs on the other side of the pond and pull them into the pond. If you fill the pond with sand, the rocks will land on the sand and not hurt anything when they fall 4 feet. Then you can dig out the sand afterwards.

Just hire some guy with a bobcat. He could put them exactly where you want them. Be through in 15 minutes. All you have to do is point your finger where.

Hi, It seems to me as you maybe making a bigger deal out of it than need be. I think I could move those rocks by myself, not lifting but tumbling. For sure two guys from any lawn service for $50.00? Like the guy said above, any machine, skidsteer, tractor, hoe, decent riding lawn mower moves those in minutes, where ever, how close, no big deal. I'm certainly not trying to be cheeky, the size rocks you described I move in granite. I think you should ask the local farmer you got them from to come move them for you. If there is a slope that leads to the water and your afraid they'll roll in, then the mover should dig the rocks bed before getting them there so the rocks fall into them, with a contolled decent, as well as hitting the removed dirt bank to stop them, again I think those rocks are controllable as long as the grade is not extreme.