Water right system is an important content of water right theory, and establishing and perfecting water right system is an inevitable way to realize optimal allocation of water resources. Because the water right system involves a wide range of contents, this paper discusses the role of water right system in promoting water conservation in combination with the reality in Jiangsu. 1. The water right system can realize the optimal allocation of water resources (1. Analysis of the causes of current water resources waste) Huaibei area of Jiangsu Province is the main water shortage area in the province. Since the founding of New China, the inter-basin water transfer project has been built in our province, which has successfully realized mutual assistance and intermodulation between the Yangtze River and Huaihe River, and between Huaihe River and Huaihe River. However, from the point of view of today's resources and water conservancy, the problem of saving water has not attracted enough attention, and the waste of water resources is more serious. There are many reasons for wasting water, such as backward production methods, insufficient investment in water-saving projects and inadequate water-saving facilities. From a deep analysis, there are three main reasons: 1. Water transfer is mainly manifested as the administrative function of the government, regardless of cost. As Jiangsu Water Transfer Project was built during the planned economy period, its management system and operation mechanism were also formed under the planned economy system. The implementation of inter-basin water transfer mainly considers social benefits to meet the economic and social water demand, and the water supply unit itself has no economic accounting and no consideration of cost. Water users emphasize the right to use water, regardless of the relationship between input and output. During the irrigation season, farmers only know that the government wants to supply water, but they don't know the cost of water transfer. 2. Low-cost charges and incomplete metering charges have caused the de facto drinking of large pots of water. Since the reform and opening up, the water price in our province has been divided into four steps. However, so far, there is still a big gap between water price and the cost of inter-basin water transfer. According to the investigation and analysis of 22 counties in 5 cities in northern Jiangsu, the current water price only accounts for about 10% of the average water supply cost. The provincial finance subsidizes the operation of water transfer more than 1 100 million yuan each year (mainly to pay the electricity fee), and the water supply project cannot achieve the benign operation of maintenance and renewal. In the way of collecting water charges, metering and charging are not fully implemented, which objectively causes users to use less water and still drink large pots of water. 3. In the allocation of water resources, the mode of on-demand supply is adopted. The inter-basin water transfer project in northern Jiangsu mainly considers the water transfer scale and water allocation according to the demand, and implements water transfer according to the needs of people's life and industrial and agricultural production in northern Jiangsu. Especially in agricultural production, a large-scale water transfer project has been implemented to meet the needs of large-scale drought relief in northern Jiangsu. This is absolutely necessary to stabilize and develop agriculture, especially to solve the problem of people's feeding. However, compared with the requirements of today's socialist market economy and rational utilization of water resources, there are still many unsuitable places. (II) Principles of Optimal Allocation of Water Resources The water rights system is based on the theory of property rights. Property right refers to people's right to use a certain resource when resources are scarce. Therefore, the property right system has the function of effectively allocating scarce resources. Similarly, the water right system has the function of efficient allocation of water resources. The so-called high efficiency is to optimize the allocation, that is, to maximize the benefits of limited water resources. From this point of view, the optimal allocation of water resources is the most fundamental and meaningful water saving. This aspect should be promising, and at least three aspects can be studied: First, the principle of safety first. That is to say, in the order of water use, people's life safety should be considered first, followed by food safety, and on this basis, the water use of all walks of life and ecological environment should be considered as a whole. The second is the principle of efficiency priority. In other words, while ensuring safety, the utilization of water resources should pay attention to efficiency and pursue the maximization of water resources utilization efficiency. For industries, departments and regions with low efficiency, priority should be given to those with high efficiency. The third is the principle of supply and demand. That is, according to the situation of water resources, supply capacity and guarantee degree, determine the scale of economic development and the departments and industries that give priority to development, and adjust the industrial structure and development direction. (III) Problems that should be paid attention to in optimizing the allocation of water resources According to the practice of inter-basin water transfer in Jiangsu, in the process of establishing water rights system and optimizing the allocation of water resources, we should pay attention to the following three problems: First, make full use of water resources in water transfer areas. Before the implementation of inter-basin water transfer, the situation of surface water, groundwater and transit water in this area should be comprehensively evaluated, and various comprehensive measures should be taken to make use of them as much as possible. On this basis, the scale of inter-basin water transfer is determined according to the needs of social and economic development. The second is to fully tap the water-saving potential of the transferred areas. The allocation of water resources must be based on water saving. As far as a region is concerned, the amount of water resources is limited. However, by adopting various water-saving measures, the available water can be increased to a greater extent, thus reducing the demand for inter-basin water transfer. This is "pay equal attention to throttling and open source, and throttling is the first." The third is to calculate the cost of water transfer and the income from water use. Under the socialist market economy system, the implementation of inter-basin water transfer needs not only safe water use, but also economic benefits. It is necessary to comprehensively calculate the cost of water transfer, analyze what the transferred water is used for and how much benefit it can produce, and determine whether it needs to be adjusted and how much it is appropriate. At the same time, the market mechanism is introduced into the water transfer project construction system. Second, the water right system will inevitably have an effective restriction on water use behavior. (1) theoretically, the restriction of water right system on water use is mainly manifested in two aspects: first, clear water rights make public goods become private goods. The ownership of water resources belongs to the state. Before the right to use water resources was clearly defined, water was actually a public good. As long as people have access to water resources, they can use it without scruple, with less use and no benefit to users. However, once the water right is clear, the water users will get the right to use water resources, and at the same time, the rights and risk responsibilities of these rights will be clear. At this time, the water resources with clear water rights have actually become the private property of users, and how to use them is more or less directly related to the interests of users. Therefore, users should consider whether their water use behavior is appropriate. Free Postgraduate Entrance Examination Network www.freekaoyan.com