Water is essential for life, so understandably, most ancient civilizations they emerged around water. Examples is Babylonia around the Tigris and Euphrates in ancient Iraq. Angkhor Wat in Cambodia, which emerged around 1000 years ago. And Dujiangyan in China, which is the oldest preserved water structure. It is actually a very interesting structure, because it diverts water from a river using the natural river flow. So separate the water with lots of sediment from the clean water, which then enters the irrigation canals. And also we provided drinking water for the population at the time. But today I shall talk about integrated urban water management. This is a concept emerging from the water tank to consider the sustainable use of water resources in an urban aspect. The perspective is to reduce water consumption or to make efficient use of the water that is available for an urban area by considering it in the context of the watershed or the catchment area that this urban area is located. It does not include water supply and based water directly. But it does include the efficient use of water, the reduction of the use of water in order to conserve water, and the reuse of based water as an additional source to freshwater from the catchment. Integrated Urban Water Management is also a subset of what we call Integrated Water Resources Management, a concept that emerged in the 1990s, and still governs water management in many parts of the world. It has become increasingly important in recent years because of the extreme urbanization that is going on. In Africa as well as in China it is expected that over the next ten to 15 years 300 million people will move to rural areas to urban areas. Placing an incredible strain on the supply of water, and on the discharge of waste water. It is tackled very differently in China. They have applied a supply driven management, or supply driven development in order to provide the necessary water for Beijing and Tianjin the big million cities in the northern part of China. They have built the South to North Water Transfer. It actually has two branches. One from Wuhan in central China to Beijing. And one from the lower reaches of the Yangtze River to the province of the North China Plain and to Shandong Province south of the plain. The interesting thing in water resources management is that this covers only the current deficit of groundwater extraction in the northern regions. So it means that even with this large inflow of water, it's some 30 billion cubic meters, equivalent to 30 cubic kilometers of water every year. Even this large influx of water, it is only sufficient to cover the current deficit. It does not allow for lot of development. In addition, a lot of the water is actually used by the provinces, allocated to the provinces along the road from the Yangtze basin is still waiting. So it is seen as a silver bullet by the counties and by the city of Beijing to its water shortages but in my personal opinion it is only a short break before they run short of water again and have to introduce new measures. And in this case, we will be talking about different measures to curb the use and the demand for water, called Water Resources Demand Management. In Copenhagen, integrated urban water management started around 1850 in response to the two big cholera outbreaks. So cholera, in the city. As a result the Copenhagen Water Company decided to supplement the use of surface water from the lakes around the city by abstraction of ground water. And today all water use in Denmark comes from ground water sources. The latest domestic water supply, industrial water supply, and irrigation. The advantage of ground water is that it requires only simple treatment by aeration, which will blow away some of the dissolved gases in the water and by subsequent filtering of iron and manganese hydroxides. And this way we can deliver clean water of a very good quality. In fact, it is now in better than Danish legislation that water, drinking water, must be produced only by simple treatment. No advanced treatment for pollution is allowed. And this of course places a great strain on how to obtain sufficient ground water. So we know our ground water resources extremely well You will notice that the water consumption in Denmark shows a steady decline in recent years. This is a convincing illustration of water demand management. The decline is in clear response to increasing prices for water. In fact, Denmark today has the highest price of water of any country in the world. But we also have some of the best water quality. Everywhere in Denmark you can drink water from the tap. And importantly this decline in the use of water, in the demand for water has not effected our production. We have managed to decouple the gross domestic product from the water use. And which is a lesson that can be taken around the world. In terms of integrated urban water management Copenhagen has not been able to restrict its water to its immediate surroundings. But has actually now developed a network that reaches more than 100 kilometers away from Copenhagen. The water is fracted from a number of ground water wells. And treated locally in water treatment plants before it's transmitted to Copenhagen. At the time of the cholera epidemic, the Copenhagen municipality also realized that it was necessary to remove the wastewater from the streets. This being very, very unhygienic and also a major risk for transmission of diseases. So huge sewers were built underneath Copenhagen, and some of these still exist today. Where, some of them are reused for pipelines for water as well as for the district heating of the city.
