Water transfers between river basins

Lost in the shuffle

According to a recent WWF study, large-scale projects to transfer water from one river basin or catchment to a neighbouring river basin, worsen social, economic and environmental problems instead of solving them.

The study, Tagus Segura - Lessons from the Past, examines the disastrous ecological, social and economic consequences of the Tagus-Segura Transfer in Spain. One of the conclusions is that such transfers only increase the thirst for more and more water, resulting in a spiral of unsustainability.

Many of these projects, or Inter-basin Water Transfer Schemes (IBWT), were completed in recent decades and many more are in various stages of preparation around the world. Analyses show that many of these began for political reasons and all had a strong technical challenge and appeal. However, most of these projects are economically unfeasible without massive subsidies and end up damaging the ecology in both basins.

Especially during the 1950's and 60's when many of the large IWBT were planned and constructed, environmental awareness was low and getting the public involved not so common.

The prospect of huge concrete structures, high-tech pumping systems and thousands of kilometres of channels providing water and energy was an intellectual challenge to the engineering society and a seemingly irresistible package for governments with benefits for everyone involved.

With hindsight, however, a number of drawbacks are strikingly clear:

• Water wastage
  Water evaporation and seepage from the channels often waste at least 50% of the water removed. Water shortage in the basin to which water is transferred is often due to poor water management, and especially to the fact that water is free or priced below its economic value. This wastage will continue even when there is more water.
  
  
• Ecological damage
  The altered hydrological regime of the river from which water is taken leads to irreversible ecological damage. Dams constructed on the rivers from which water is taken have a devastating impact on river ecology, especially on migrating fish.
  
  
• Threats to farmers' livelihoods
  Without massive government subsidies, farmers in areas receiving water could pay as much as 1 USD per cubic meter, making their produce more expensive locally than on world markets and threatening their livelihoods.
  
  
• Losses in two basins
  Even when "only" 10 to 15% of water is taken from one basin, this is already enough to cause droughts in both basins in times of little rainfall - the basin from which water is removed and the other where it is put.