|
|
||||||||||||||||||||||||||||||||||
 |
||||||||||
|
 |
|
|
|
|
|||||
|
||||||||||
How We Work: Water and Cities
 Almost all major cities are built on or near a river, lake or other reliable source of fresh water. © Photos.com Water and Cities -
|
Increasing Demand
Nearly 3 billion people live in the world’s cities today, and that number is expected to grow to 5 billion by the year 2050. While water demands in agriculture and industry have leveled off in many regions, the water needs of most cities continue to grow at the same rate as their populations. More water – perhaps as much as nearly 70 percent more than is being used today – will be needed to support city dwellers in coming decades.
Growing urban water demands are putting a huge strain on the world’s freshwater ecosystems. Cities typically exhaust nearby water sources first, but many large cities now reach hundreds of kilometers in their search for water, tapping far-distant rivers, lakes and ground water aquifers. Excessive water extractions can damage freshwater ecosystems and reduce the societal benefits provided by healthy ecosystems.
Taking Action
The Conservancy is working with cities to find ways to meet future water needs without degrading freshwater habitats. Conservancy scientists begin by helping to define the water flows or lake levels needed to sustain the natural ecosystems from which water is being withdrawn. They then work with urban water planners and managers to minimize their water needs through water conservation and drought management, and help design their water supply operations such that the location, timing and amount of water withdrawals are ecologically sustainable.
