Pond Boss Forums POND CONSTRUCTION Renovating a Pond or Lake? How to make existing spring-fed pond deeper?

I can't say what will be cheaper, but whoever you get, make sure they know what they are doing. If the pond was dug in sand, and a clay liner was placed and packed, if you dig the clay out, the pond won't hold water anymore.

Costs will also depend on how far the removed dirt has to be moved. You can get a large pump, pump the pond down, dig a deep hole, funnel the water to it, keep pumping it out, and dig around it using an excavator.

Don't drain at all and have a dragline come in and dig it deeper. No matter how it is done, I'd get a written contract specifying how deep the pond will be, and how much of it will be that deep, specifying the existing water level for a baseline to measure from.