 the water, settling near rivers, lakes, and springs, and moving to others if these dried up because of climate variability. As technology evolved and settlements became larger, people moved the water to them. In the so-called Middle Ages, water was generally distributed by water carriers, or collected directly from wells, ponds and rivers. It was only in the mid-19th century that the connection between water and disease was established, highlighting the need for separation between sewage disposal and water supplies. Before then, sewage was disposed of via watercourses that provided the supply for others. This situation still prevails today in many less developed countries, even where water is abundant. The industrial revolution in the West and later in the East could not have occurred without adequate water or reliable and healthy workers. It is no coincidence that many of the countries nowadays with the most comprehensive water INFRASTRUCTURE TO 2030: TELECOM, LAND TRANSPORT, WATER AND ELECTRICITY - ISBN 92-64-02398-4 © OECD 2006 5. THE IMPACTS OF CHANGE ON THE LONG-TERM FUTURE DEMAND FOR WATER SECTOR INFRASTRUCTURE infrastructure are those that were at one time colonial powers. Revenue from colonisation provided the funds to construct many of the water infrastructure assets in the 19th century, most of which are still relied on today. The establishment of modern water systems was originally largely based on private initiatives. These proved unreliable and from 1861 to 1901 the share of municipal water supplies in England, for example, grew from 40 to 90%. A similar trend was also evident in the United States. The growth of urban infrastructure was the most dynamic element of the British economy from the 1870s to the 1930s. Investments in public health, local transport, water, electricity and gas were by the early 1900s as much as one-quarter of all capital formation in Britain. In North America many urban water supply systems were built from 1830 to 1880; it proved more difficult to fund sewage systems (rather