Definition of several common water levels

Normal storage level

The highest water level in normal operation of the reservoir. Also known as normal high water level. When the reservoir is used abnormally according to the flood control requirements, the water level of the reservoir will generally be higher than the normal water level, but it cannot exceed the check flood level related to the safety of the reservoir. Normal water level is one of the most important design parameters of reservoirs and hydropower stations, and it is the basic basis for determining the height of barrage, reservoir volume, utilization head and power generation capacity. It has a great relationship with the engineering quantity of hydraulic structures, the regulation performance of reservoirs and the utilization of water heads. It has an important impact on the construction period, investment, kinetic energy economic benefit and reservoir flooding loss of reservoirs and hydropower stations. When the hydropower station has other comprehensive utilization tasks besides power generation, the selection of normal water level should consider the requirements of comprehensive water use departments such as hydropower generation, flood control, irrigation, shipping and water supply, and compare multiple schemes. Generally, the following aspects should be studied: ① the growth of power demand in the development of regional national economy; (2) The requirements of the comprehensive water conservancy department for the development and utilization of water resources; (3) The restriction of topographic and geological conditions of dam site and reservoir area, and the size and distribution of annual runoff; (4) Consideration should also be given to the allowable degree of flooded immigrants in the reservoir area, especially the height restrictions put forward by important towns, railways, highways and precious mineral resources, as well as other places such as grain and cotton bases, tourist attractions and important places of interest; ⑤ For reservoirs and hydropower stations built on various border rivers, the requirements of upstream and downstream banks and left and right banks should be well coordinated, so that the determined normal water level can be accepted by all parties.

When selecting the normal water level, we should first determine the upper and lower limits according to various requirements, then draw up several schemes within this range, make calculation and analysis on water conservancy, kinetic energy, economy and other aspects, then make comprehensive comparison on politics, technology and economy, conduct environmental impact assessment, and select the best scheme. When determining the normal water levels of cascade hydropower stations and hydropower stations, we should also consider the needs of reasonable connection and mutual compensation and adjustment between upstream and downstream water levels.