Depending on the shape of the existing pond, it could cost as much or more to re-do it.
Look at that state/counties NRCS office, they might be able to help with a list of pond contractors. YMMV, some county offices are absolutely no help, others are wonderful.
https://www.nrcs.usda.gov/wps/portal/nrcs/site/national/home/Yes to having a consultant come out. That's been done by a number of people. Hate to buy a piece of property specifically to build a pond and find out that it will be impossible or cost more than the budget allows.
