1. Overview of water resources in the United States

The United States is located in the center of North America, with a total area of ??9.37 million square kilometers. Various landform types such as plains, mountains, hills, deserts, lakes, and swamps are distributed in the vast territory. Mountains account for one-third of the land area, and hills and plains account for two-thirds. The terrain on the east and west sides of the territory is It is high and low in the middle. The east and west are roughly bounded by the east foothills of the Rocky Mountains in a north-south direction. It is also the watershed between the Pacific and Atlantic water systems of the United States. The climate and natural conditions on the two sides are quite different. ?

Most rivers in the United States run north-south. The main water systems are: the Gulf of Mexico water system, which is composed of rivers such as the Mississippi River and the Rio Grande River. The drainage area accounts for two-thirds of the area of ??the continental United States; the Pacific water system, including The Colorado River, Columbia River, Sacramento River, etc.; the Atlantic water system, including the Potomac River and the Hudson River, etc.; the Bering Sea system, consisting of the Yukon River and other rivers in Alaska; the Arctic Ocean water system, including the inflow into Alaska Arctic Ocean rivers. ?

According to the natural distribution of precipitation, the characteristics of water resources in the United States can be summarized as: more in the east and less in the west, and abundant per capita. The multi-year average precipitation in the United States is 760 mm. Taking 95 degrees west longitude as the boundary, the local United States can be divided into two different regions: the 17 western states are arid and semi-arid areas, with annual precipitation below 500 mm, the inland areas of the west are only about 250 mm, and the lower reaches of the Colorado River Less than 90 mm, it is an area with relatively scarce water resources in the United States; the annual precipitation in the east is about 800 to 1000 mm, which is a humid and semi-humid area. The total amount of water resources in the United States is 2,970.2 billion cubic meters, and the per capita water resource is close to 12,000 cubic meters. It is one of the countries with abundant water resources. ?

2. Water resources management in the United States

After nearly a century of construction, the water resources development and utilization projects in the United States have basically formed a system to control local floods and water resources in the west. The allocation has reached a high level. It can be said that the stage of large-scale development and utilization of water resources in the United States has ended. Today, when the further development and utilization of water resources has been severely restricted by ecology and the environment, the focus of water resources work in the United States has shifted to efficient management, focusing on improving water use efficiency and preventing water pollution. The main features of its water resources management are:

1. A state-based water resources management system. Since the United States is a federal country, water resources belong to the states, and water resources management is basically carried out by the states. There are no uniform water resources management regulations across the country, and management actions are governed by state legislation and interstate agreements. Water bureaus are often divided into several water bureaus below the state level to coordinate and manage water-related matters such as water supply, drainage, sewage treatment and reuse. Take the Southern California Metropolitan Water Authority we investigated as an example. This water resources management agency was established in 1928. Initially it was only responsible for water supply in 6 counties and 5,200 square kilometers. It purchased water from the state water supply project and then passed it on to the next-level water agency. Bulk sale. With the increase in population and economic development, the functions of the Water Supply Bureau can no longer be limited to simple water supply. Instead, they must take into account the water needs of industry, agriculture, service industries and ecological water, and uniformly plan and dispatch external water supply, regional surface water, Groundwater and wastewater treatment and reuse to meet the needs of regional economic and social development. Although such a water authority is not a government department, state legislation gives it management authority and overall responsibility for regional water resources and water environment, allowing the United States to achieve unified management of water resources to a certain extent.

2. Administrative measures are mainly reflected in the formulation and implementation of plans. The state-led water resources management system does not mean that the federal government can only sit on the sidelines in this regard. Historically, relevant federal departments in the United States have carried out the construction of a large number of water conservancy infrastructure projects, and have also coordinated, formulated and supervised the implementation of many state-level water distribution agreements. In the Geological Survey Bureau of the Interior Ministry, the Bureau of Reclamation and other departments we visited, there are currently some plans and plans being formulated or implemented. These plans involve water resources survey and evaluation, water quality monitoring, water conservation, water ecosystem restoration, etc. All are enforced by the Federal Investment Guarantee. Through planning, formulation and implementation of plans, water resources management in the United States will be promoted to be more scientific and efficient.

At the California Department of Water Resources, state staff are working on revamping the California Water Plan. The "California Water Resources Plan" formulated in 1957 is written into California law, which means that the plan must be revised every five years. This revision will add new content such as drought countermeasures, water-saving measures, environmental climate change, etc., and make predictions about California's water supply and demand in the next 10 years. The future administrative measures of the Water Resources Bureau will mainly be reflected through the implementation of this plan. ?

3. Give full play to the role of the market in water resource allocation, and set water prices in compliance with market rules. The United States is a highly market-oriented country, and market-driven mechanisms are everywhere. From the construction of large-scale water conservancy projects to the allocation of water resources in water supply areas, their financing, supply and demand are all regulated through market mechanisms. In the Southern California Metropolitan Water Bureau, water supply, water storage, water delivery, groundwater extraction, wastewater treatment, groundwater recharge, etc. are all operated for a fee. The Water Bureau conducts real-time dispatch through the water resources dispatch model based on water demand and water supply conditions to meet user needs. The basis for the operation of this dispatching system is market-oriented management, and water resources are priced based on quality and cost. Different prices determine the distribution of various water sources, and also promote the adjustment of industrial structure, allowing wastewater to be treated and reused, and water resources to flow to more profitable industrial sectors, that is, "water flows to higher places." ?

Water rights and land ownership in the United States are inseparable. The inheritance, transfer and transaction of water use rights vary greatly from state to state, and are very cumbersome because they involve many legal issues. In recent years, the water rights trading system of water banks has emerged in the western region of the United States. The annual water resources are divided into several parts according to water rights, and the water rights are managed in the form of a shareholding system, which facilitates the transaction process and maximizes the economic value of water resources. fully reflected.

The establishment of water prices in the United States follows market rules and basically takes into account the value of water resources, the cost of water supply and sewage treatment, and investment in new water supply capacity. Water fees include water supply bonds, resource taxes, sewage treatment fees, testing fees, pipeline connection fees, etc. Water prices are revised annually. The United States also pays attention to the leverage effect of water prices on water conservation. In recent years, the annual increase in water prices has reached 8%, which has played a positive role in maintaining zero growth in water use nationwide after 1985. Water rights, water prices and the operation of the water market make increasing revenue and reducing expenditure a conscious action regulated by the market mechanism. Although there are problems of management failure, its role in promoting the sustainable use of water resources in the United States is obvious.

4. Saving and protecting water resources is the focus of management. When talking about the current main tasks in water resources management, water resources departments at all levels in the United States emphasize the importance of conservation and protection. The water structure of the United States has basically stabilized 20 years ago, with residents' domestic water accounting for a higher proportion. During the growth period of total water consumption from 1950 to 1980, agriculture and industry due to structural adjustments, cost reductions and restrictions on wastewater discharge Due to strict restrictions, water use has been declining, and the fastest growing water use is that of urban residents and service industries. To this end, the western states in the United States, which are relatively short of water resources, have taken many water-saving measures, promoted household water-saving appliances, reformed water prices, and carried out water-saving publicity. Some states have very detailed restrictions on residents' water use, and even have clear regulations on when to irrigate lawns. In order to encourage water conservation, the government has formulated detailed economic policies. Households, commercial units, and factories that adopt water-saving measures will receive varying degrees of incentives and subsidies. Water conservation measures have effectively curbed the growth in water consumption. Nowadays, water conservation is highlighted as a main measure in all relevant plans and plans, especially in the western states. In the relationship between increasing revenue and reducing expenditure, the first priority is to emphasize expenditure reduction. ?

In terms of water resources protection, the United States attaches great importance to reducing pollution of rivers and maintaining water ecosystems. There are currently more than 20,000 sewage treatment plants built in the United States, and sewage collection and treatment systems of various sizes ensure high sewage treatment rates. Some cities have designated large areas of water source protection areas. For example, the San Francisco government purchased drinking water source catchment areas and adopted strict protection measures. In the process of water resource development and utilization, the United States has conducted a lot of research on the maintenance of ecosystems. Western reservoirs managed by the federal Bureau of Reclamation all require the release of ecological water to ensure the water needs of animals and plants.

In recent years, the U.S. Geological Survey has launched a plan to monitor and evaluate groundwater across the country to encourage states to take measures such as recharge to strengthen groundwater protection.

5. New technologies are applied to water resources management. In terms of water resources survey and evaluation, planning, and real-time monitoring, relevant U.S. departments extensively apply advanced science and technology, such as remote sensing technology, satellite transmission, and geographic information systems. The U.S. Geological Survey is responsible for the monitoring, evaluation and scientific research of water resources. It has 7,028 observation sites covering various rivers and water sources in the United States. The technical means are very advanced. These monitoring sites are all connected to satellite networks, and any site can Monitoring data that occurred two hours ago can be found on the Internet. The bureau not only carries out normal water resources observation and evaluation work, but in recent years has also taken the lead in using mathematical models to conduct research on the quantity and quality of groundwater in the United States. Its technical methods are worth learning from.

Real-time dispatch of water resources is also very common in the United States. Many water supply districts allocate water through computer models, and automated control plays a role in promoting the scientific allocation of water resources.

6. Continuously carry out reforms. The water resources management office in the United States is constantly undergoing reform, and institutional issues are the focus of reform. The most popular one currently is the privatization reform of water supply and sewage treatment industry. As the U.S. environmental protection department has put forward higher water quality requirements for water supply, a large number of water supply pipelines that are more than 20 years old need to be replaced (70%). In addition, water treatment costs will also increase. The large demand for funds in the water supply industry calls for the investment of private capital. injection. More than 90% of the current water supply and sewage treatment enterprises in the United States are owned by counties, cities and various communities. Insufficient funds and lack of talents make enterprise transformation difficult; and the U.S. water supply industry, with a return on investment of 20%, has a great impact on its domestic and overseas development. Private capital is extremely attractive, so the trend of privatization in the water supply and sewage treatment industry is obvious. In some areas, there are an increasing number of private water plants and entrusted management of water plants. The results of a survey by the American Water Companies Association show that the reform of the water plant system has brought about a series of changes: water quality has improved, water user complaint rates have decreased, and operating costs have decreased. More importantly, privatization has brought capital, work efficiency, and quality services, injecting vitality into the U.S. water industry.

3. Development and utilization of water resources in the western United States and the North-South Water Diversion Project

Similar to my country, the western United States is also a major water shortage area compared to the eastern part. The western United States is dominated by mountainous plateaus, mainly composed of the Pacific Coast Mountains, Columbia Plateau, Colorado Plateau and Rocky Mountain Mountains. The Pacific Coast has a temperate maritime climate, with dry summers and mainly winter precipitation. The annual precipitation in most areas is less than 500 millimeters, especially the California region adjacent to the Pacific Ocean, which has the highest population density in the United States and the highest degree of industrial and urbanization. Water shortage has long been one of the major concerns of the US federal and California governments.

In the long history of western development in the United States, the development and utilization of water resources has always been a top priority. As early as 1902, the federal government established the Bureau of Reclamation to develop and utilize water resources in the Midwest. After nearly 100 years of efforts, 348 reservoirs, 267 pumping stations, 216,000 kilometers of channels, and water transmission have been built in the west. There are 2,300 kilometers of main pipelines and 58 hydropower stations. The construction of these projects has laid the foundation for the allocation of water resources in the western United States and the economic and social development of the western United States. With the Hoover Dam, the beautiful city of Las Vegas in Nevada existed; without the North-South Water Diversion Project, Los Angeles, the second largest city in the United States today, would no longer be as beautiful as it was today. ?

A typical example of water resource development and utilization in the western United States is the North-South Water Diversion Project. The North-South Water Diversion Project is a configuration project designed to solve the water shortage problem in California. California, located on the west coast of the United States, is long and narrow from north to south, with undulating terrain and uneven rainwater distribution. The north has more rain and frequent floods; the south is densely populated and has scarce rainfall. Especially in Southern California, which is home to two-thirds of the state’s population and is an area of ??rapid economic development, water resources conflicts are very prominent. The area relies primarily on river water and groundwater diverted from the Colorado River in northeastern Nevada.

However, as states control and protect their own water sources, as well as ground subsidence caused by over-exploitation of groundwater, the California government has been forced to consider water resource allocation strategies to solve droughts in the north and south since the 1950s. In 1960, the California referendum supported the North-South Water Diversion Plan, which enabled the construction of a water diversion project with a total length of more than 600 kilometers. The main road of the project was completed in 1973, and since then, improvement and supporting work has continued. The entire project has 28 dams and reservoirs, 22 pumping stations and some power stations. The annual water transfer volume is nearly 5 billion cubic meters, which is used by 20 million people in California. 70% of the water transfer volume is used in cities and 30% is used for irrigation. Covering more than 3.6 million acres of farmland, it is currently the longest and highest water diversion project in the United States and even the world. ?

The main investment in the North-South Water Diversion Project is US$1.75 billion, all of which comes from long-term bonds. The state Water Resources Bureau signed long-term water contracts with 29 local water bureaus at the time based on water needs, and then used water fees to repay the bonds. . This kind of market-oriented capital operation not only solves the funding problem of project construction, but also lays a good foundation for the operation and management of the project. Judging from the current situation, the construction of the North-South Water Diversion Project is successful. Even the environmentalists in the United States who are the most fiercely opposed to the construction of water conservancy projects fully affirm the achievements of this project.