I design earthworks for a living, have my own heavy equipment and have built 6 ponds on my property. Here is what I have learned along the way.
Forget about using a normal tractor to move than a small amount of earth. Its too slow and you will tear the tractor up because most tractors, at least below 100 hp are not built for heavy earth moving.
For small ponds, (<3/4 acre), a small dozer like a Cat D3 are great. Plently of hp for the blade size and they are built to push and rip earth
For larger ponds a Cat D6 or larger is really the way to go. They are big enough to push a serious amount of earth with each blade full. If you are pushing more than 100 feet, get a scraper to work with the dozer. I have a Fendt 105 hp ag tractor with a 6 cy leon scraper and it can out perform a dozer if the haul distances are long. The scraper has a difficult time loading if the clay soils are hard.
Dozers aren't that hard to learn how to use, you just have to be careful, go slow and not tip the machine over and kill yourself.
You can rent a D3 for $400/day plus fuel in most areas. If you are handy with equipment you can learn to run a dozer in a day.
I own a D3 and for my larger ponds rent a D6 with the operator. I built a two acre pond with these two dozers in two days. It had an average depth of 16 feet and required movement of about 1500 cy. It cost me $3000 for two 10 hour days for the D6 and I put about 24 hours on my D3.
You can save alot if you do some of the work yourself, just go slow and be careful.
