When a pond gets over grown with weeds and full of sediments from leaves, aquatic weeds, twigs and branches, and decaying organisms such as fish and snails. The pond then needs to be dredged. This usually needs to take place every ten years or so. The dredging process will turn your pond back to its original condition or most times better. In some cases only the edges of the pond need to be dredged. In some severe cases the entire pond would need to be pumped down and cleaned. Depending on the size of the pond this could take a day and up to a week. The spoils that come out of the pond should go somewhere on the property to save time and money. If they need to be hauled away it can sometimes double the cost of the cleanout.