The best situation is when you know you can trust your excavator, either by your own prior experiences or by references.

Our excavator had done several jobs before (and since) he did our pond. It was not a set bid, but depended on hours and expenses. A set price wouldn't really have worked for us, as a severe case of "mission creep" occurred and what was planned as a dammed pond turned into a dammed and excavated pond AND an outdoor arena for horseback riding (the last third of the dirt had to go SOMEWHERE).

I think one potential problem with a set price is if extra effort is required for a successful pond. If you run into a big vein of sand, porous rock, or other major problem, you $XXXX price can run out before it gets fixed, but the excavator's "done." We have seen at least a couple examples of this posted here.

Neither approach is immune from problems in the event of a disreputable contractor. So it's very important to get those references and check them out. Talk to the prior clients and see if some will let you check out their ponds. By looking at the ponds, you may see problems that they aren't aware of when giving glowing testamonials.


"Live like you'll die tomorrow, but manage your grass like you'll live forever."
-S. M. Stirling
[Linked Image from i.pinimg.com]