I actually knew I guy that built a pond somewhat larger than 2 acres. The weather would not cooperate and the summer was especially dry so he drilled a well of about 100 feet and pumped water in for a couple of weeks using a diesel powered pump (or it might have been a diesel generator paired to an electric pump). It ended up being considerably cheaper than paying city water rates to fill the thing up. I think he just had to pay a sub to drill the well, I think he had everything else on hand and the cost for 100 ft of drilling was not too much.
I have a customer that has a 2 acker pond and the part that back up to his house has been over taken by cattails, lillypads etc. He wants to fill and level it out so he is able to walk out to the edge and be nothing but a clean edge of grass 100' x 100'. I don't no the first thing to do when back filling somthing that has around 4' of standing water.