Purpose of reservoirs
According to the main purpose, water bodies are divided into:
• to decorative ponds, which mainly include small and ultra-small ponds from ready-made forms. Such reservoirs completely depend on the person (foundation pit; its facing; plants; water nutrition; water exchange, as a rule, artificial with the help of a pump, and other characteristic indicators);
• reservoirs of landscape and decorative purposes, which are an important part of the planning structure of the object. The coefficient of water exchange (the ratio of the amount of water passing through the reservoir during the year to the volume of water in the reservoir), as a rule, is 2 … 2.5. The economic use of water is not provided. When constructing such water bodies, it is necessary to provide aquatic vegetation;
• recreational ponds, which differ from landscape-decorative recreational load. The requirements for the purity of water are quite high. Such reservoirs should have a high rate of water exchange – 2.5 … 3. Domestic facilities, which meet the needs of holiday-makers, are satisfied near reservoirs. The size of recreational ponds should be large enough: firstly, to improve the self-regulation of biological processes; secondly, to reduce water pollution;
• reservoirs for water sports, which are designed and built quite purposefully, in accordance with the requirements and standards for the creation of sports facilities. Depending on the purpose of the reservoir, they are set by such parameters as the area of the water area, the depth in various places, the maximum length of the water mirror, the lining of the shores, etc. The aquatic vegetation is usually excluded. Sports facilities are erected around the reservoir, ensuring the use of this reservoir for the main purpose;
• reservoirs for sport fishing, which can be of two types: small reservoirs for individual use and larger reservoirs for collective use. In the water bodies of the first type, as a rule, large fish is launched. Such water bodies should have a water exchange coefficient equal to 4 … 5. They do not leave fish for the winter. It is caught in the fall completely.
Due to the temporary maintenance of fish, such reservoirs may not have wintering pits. Feeding fish produced moderately or even weakly to enhance biting. In reservoirs of the second type, the calculation is made for overwintering of fish, for which it is necessary to have wintering pits with a depth of 3 … 4 m in the pond. Stocking of such reservoirs can be done by both small and large fish. In the period of sport fishing top dressing is average. For growth and feeding of fish in the period of the prohibition of fishing, enhanced feeding is possible;
• ponds for fish farming. Breeding fish and provides for its catch for economic purposes. For the rapid growth of fish, it is desirable to have surface runoff water, rich in oxygen and warmer. On purely underground waters, the fish develops twice as slowly. Top dressing of fish causes pollution of the reservoir and therefore 4–5-fold water exchange is advisable. The wintering pit in such reservoirs is obligatory. With an average reservoir depth of 2 … 2.5 m, the depth of the wintering pit can reach 4 … 5 m. A distinctive feature of such water bodies can be a cage with lattice walls for catching fish by running water into this cage. After dumping the main mass of water, fish is scooped out;
• reservoirs for irrigation of the territory of the object, which are created for the accumulation and heating of water used for irrigation. This is especially important if such a reservoir is filled with cold and oxygen-poor groundwater. The water in the pond should be clean to avoid clogging of the sprinkler. A feature of such water bodies is a significant lowering of the water level during the period of intensive irrigation, during which the slopes of the water body are exposed, and sometimes parts of the bottom. To preserve the aesthetic appearance of such a reservoir within the framework of landscape architecture, it is advisable to decorate partly and temporarily exposed surfaces. It is recommended to conduct water exchange at least 3 – 5 times;
• multi-purpose reservoirs. Over time (and sometimes immediately), the reservoir simultaneously performs several functions, i.e. becomes in one way or another a reservoir of multi-purpose. Therefore, the requirements for such a reservoir depend on one or another predominance of its functions.