A determination must first be made whether the pond location is in a shoreland or wetland area. If you wish to construct a pond in a wetland or shoreland area permits will generally be required from the DNR, County zoning and possibly Corps of Engineers.
If an individual wants to construct a pond in agriculturally zoned land with five or more acres, generally a County erosion control permit is required. A conditional use permit is required to construct a pond in residentially zoned property within the jurisdiction of County zoning. A residential pond less than 100 sq. ft. is generally allowed without a permit. Most ponds will therefore require a permit, so contact these agencies to inquire about the procedure for a pond at your location.