Thursday, January 06, 2011

Wise Use of Flood Plains

Sustainable Water Projects In Europe
Water and floodplain problems - Our management of water is becoming increasingly complex. Past practices have resulted in the disconnection of rivers from floodplains – with a resultant loss in biodiversity and a requirement for complex, expensive and sometimes damaging flood defense schemes. Many of our current demands are incompatible with each other. For example, we want functioning floodplains for flood management and important biodiversity, but people want to live by rivers and we need space to build houses to account for changing demographics.

Intensive agricultural practices can have detrimental impacts on water quality, quantity, and levels that damage aquatic habitats. Water companies and authorities, and thus consumers and taxpayers, must pay to clean up water, that a subsidy or bad practice has polluted. In many countries, the bureaucracy around water management is complex and convoluted. Different aspects of water are managed separately – for example, agriculture, land use planning, water abstraction, water quality, flood management, drought management, and portable water may all be managed in different ways with conflicting objectives and different spatial and temporal scales.

Reconnecting rivers with their floodplains:
Nature Conservancy Council - Allowing periodic flooding of floodplains leads to healthier rivers, lands, and estuaries. Increasingly, techniques are being used to manage flood risks more effectively than rigid use of dams and levees. These techniques include setting levees back from river banks, changing the characteristics of buildings and roads, and protecting floodplain lands through purchase or easements. Examples of relevant projects include the Conservancy’s work on the Yangtze River in China and the Mississippi River in the US.

China's Yangtze: A River Under Threat
A River Under Threat - Originating high on the Tibetan Plateau, the magnificent Yangtze, the third longest river in the world, descends rapidly, stretching almost 4,000 miles as it surges through mountain valleys, cuts through limestone gorges and winds past lowlands to empty into the ocean at the port of Shanghai. As China’s economy rapidly expands, the health of the Yangtze River deteriorates, imperiling extraordinary aquatic species like the finless porpoise, Chinese alligator, sturgeon and paddlefish, as well as the health and safety of the people living near and dependent on the river. This system suffers from numerous threats, including:
  • Catastrophic Floods
  • Deforestation
  • Pollution
  • Sedimentation
  • Wetlands Destruction
  • Global Climate Change
  • Altered Water Flows