2. Reservoirs are divided into urban drinking water reservoirs, and fish farming is prohibited in farmland irrigation reservoirs. If fish farming pollutes the water quality, it will not meet the drinking water standard.
3. The reservoir has a large capacity and a large amount of exchange water, but after water storage, the purification capacity will also decrease;
4. The population along the reservoir is large and the environmental pressure is high. If bait cages are put into use on a large scale, the water quality of the reservoir will gradually deteriorate, and nitrogen and phosphorus pollution will be inevitable.
5. Fish farming in the reservoir area will face environmental pressure, and the risk of reservoir eutrophication will increase. The excessive reproduction of cyanobacteria has laid a huge ecological hidden danger.
Reservoir is an artificial lake built with dams and water walls in rivers, valleys, low-lying areas and places with low permeable layers, and it is one of the main engineering measures for flood storage. Reservoirs are generally composed of main dam, auxiliary dam, spillway, spillway tunnel, hydropower station, sluice row, fish-stopping equipment and other buildings. The main functions of the reservoir are flood control, power generation, irrigation, water supply and energy storage. The main function of reservoir in flood control is to regulate and store flood and reduce flood peak, especially in flood season, which plays a great role in regulating runoff and has remarkable flood control benefits.
Reservoir function:
1, the construction of reservoirs in the upper reaches can adjust the water-saving flow, reduce the impact of floods on the middle and lower reaches, and have a flood control effect on low-lying cities.
2. Solve local water use and rationally allocate water resources. For example, the South-to-North Water Transfer Project can solve the problem of water shortage in the north, increase the carrying capacity of water resources and improve the efficiency of resource allocation.
3. After the reservoir is filled with water, the upstream channel will be widened and deepened, which can improve the upstream shipping conditions and reduce the influence of seasons on shipping.
4. Hydropower is a sustainable energy source in Qingji, which can reduce the use of fuel and coal. For example, the Three Gorges Hydropower Station can effectively solve the energy crisis in southern China and promote rapid economic growth.
5. Take Dujiangyan as an example, it undertakes the comprehensive services of farmland irrigation in Sichuan Basin, water supply for enterprises and cities in Chengdu, flood control, power generation, bleaching, aquatic products, aquatic products, fruit trees, tourism and environmental protection, and its irrigation area ranks first in the country.
legal ground
People's Republic of China (PRC) water law
Article 14 The state shall formulate a national strategic plan for water resources.
The development, utilization, conservation and protection of water resources and the prevention and control of water disasters shall be formulated according to the unified planning of river basins and regions. Planning is divided into watershed planning and regional planning. Basin planning includes comprehensive basin planning and special basin planning; Regional planning includes regional comprehensive planning and regional professional planning.
The term "comprehensive planning" as mentioned in the preceding paragraph refers to the overall arrangement for the development, utilization, conservation and protection of water resources and the prevention and control of water disasters according to the needs of economic and social development and the present situation of water resources development and utilization. The professional planning mentioned in the preceding paragraph refers to the planning of flood control, waterlogging control, irrigation, shipping, water supply, hydropower generation, bamboo and wood exile, fishery, water resources protection, soil and water conservation, sand prevention and control, water source protection, etc.