How to clean a pond?

The cleaning of a pond consists of the extraction of the materials accumulated in the water. In general, a pond is cleaned following excess organic matter. Silt is usually the main problem encountered in most ponds.

This is a delicate operation, however, essential to preserve the natural balance of your pond. The fundamental objective of the project is its decongestion. If a pond is allowed to silt up, it risks eutrophying and turning into a swamp. Proper curing is important. Some ponds whose biotope is fragile are sensitive to mechanical silt cleaning. There are several solutions to naturally clean ponds over the long term.

In other words, cleaning a pond amounts to restricting waterlogging by exporting the sediments accumulated in the water. Several techniques can be used to achieve this end.

In this article, we revisit the best known techniques as much as we will mention some methods, a priori less known but which have not failed to prove their worth. If each of these techniques has its advantages and its limits, it should not be forgotten that cleaning a pond could also require an investment and, therefore, a substantial budget which is closely linked to the chosen cleaning technique. It is certainly by taking into account these different aspects (cost, efficiency, respect for the environment, etc.) that an option will be made.

The so-called mechanical cleaning

This method of cleaning ponds is done through the use of mechanical devices. This is the deployment of buckets which, from the bank or the surface of the pond or from the bottom of the pond, manages to extract the bulky materials. Several types of machines are used during this operation. We can cite the hydraulic shovel (easy to handle, it is suitable for ponds around 15 meters wide); the spider shovel (usable from the bank but also in the water, it is still impossible to use in marshy perimeters); the pontoon bucket shovel (it can be used for ponds up to 20 m wide); the amphidredge (its legs are mobile and perfectly designed to float on water; it is one of the gears most suited to marshy areas); the dragline (it is a machine whose maneuvering requires stable ground and a clear bank).

Mechanical cleaning has the advantage of going faster thanks to the deployment of machines adapted to the task. This is also why, “in France, it has been used in more than 60% of cases for the extraction of gravelly and uncontaminated sediments since the 1990s, all waterways combined”. However, using this technique can be expensive. In addition, it causes extensive damage to the bank. This is due to the movement of the machines used; they are generally heavy. This is why, although quick to devote to the task, mechanical cleaning could, over the next few years, be used less and less.

Dry pond cleaning

The technique consists of simply emptying the pond of its contents. Dried up, the pond is easier to access for all kinds of gear to clear it of its invaders, that is to say useless materials. It is no longer necessarily the machines mentioned above. The use of other machines, even those unsuitable for cleaning ponds, can be used with the possibility offered by the drying up of the pond of circulating at its bottom and picking up the materials using a marsh bull and a loader or a tractor-trailer.

Hydraulic cleaning or vacuum dredging

One of the biggest advantages of this technique is that it avoids damage to the bank. Hydraulic cleaning consists of sucking up the mixture of water and silt and pushing them back via a pipe to another basin prepared for this purpose. This method, as underlined above, does not require any movement of machinery on the bank. Certain specific materials and equipment are necessary for the work. We can cite, among others: the dredge with a horizontal cutter (it cuts the materials and uses a drainage to suck them out); the rotary and horizontal cutter dredger (it is designed to remove heavy materials as well as vegetation. Its specificity is its ability to lift and drain materials stored in the pond before they are sucked up); the water pressure or rotary cutter dredger (it makes it possible to extract materials by rotation or by pressurized water jet); the submerged pump (this is a pump that has the ability to go deep into a pond in order to clean out materials located at its bottom; it is designed to reach a depth of 20 meters in the water) .

Bio-Augmentation

It is a cleaning qualified as biological. This qualification is explained by the fact that the technique of bio-augmentation does not involve a cure strictly speaking. Instead, it uses a process that involves the use of natural beneficial bacteria. These spread into the aquatic environment and lower the level of mud at the bottom of the pond. This process is increasingly favored in view of its efficiency. However, its adoption is not only due to its effectiveness. It is even more a technique that does not require the use of specialized equipment. The advantage lies, therefore, in the fact that it is a question of a less expensive technique. Furthermore, the bio-augmenting method helps to preserve the pond's ecosystem by avoiding cleaning it out in the true sense of the term. It is useful to emphasize the need to combine bio-augmentation with the use of a pond aerator in order to oxygenate the aquatic environment and thus allow the bacteria a greater efficiency of action.

The gentle curing

Rare to use, soft cleaning is a technique that allows you to use a stick that comes in the form of a scoop to recover the materials that have settled at the bottom of the pond. This is, in the technical sense of the term, a difficult operation to carry out. Not only will the method require a long period of work, but it will also have to be exhausting when one imagines the size of the mud that could be at the bottom of the pond.