Pipe dreams? looked at existing and proposed large water transfer schemes in Spain, Australia, Lesotho and South Africa, Greece, Brazil, Peru and China and found the schemes to be high cost, high risk solutions to water problems 'with the benefits much less, or likely to be much less, than the sales pitch,' Geiger said.
By 2020, large scale water transfers from one river basin to another are expected to reach around 800 cubic klometres a year - around half a Lake Ontario or more than eight Lake Genevas. With problems evident in many of the 360 schemes implemented since 1950, the total number of schemes is predicted to reach between 760 and 1240 by 2020.
Australia's Snowy Mountains Scheme took 99 per cent of the iconic Snowy River's flows to produce power and provide for distant irrigation, causing generations of conflict. Despite expensive re-engineering and irrigation efficiency schemes, implementation of a decision to return a forth of the Snowy River flows is well behind schedule while climate change impacts are threatening to seriously reduce power generation.
Both donating and receiving basins experienced depletion and damage as Spain's 282 km Tagus-Segura transfer provoked a unrestrained expansion of irrigated land, much now watered illegally. Planners were wildly optimistic about the water available and while users of the transferred water were to pay for the scheme and its operations only around 30 per cent of these payments have been collected.
Greece's proposed diversion of the Acheloos River, mainly an economically questionable US$ 3.9-5.9 billion (€ 2.9 - 4.4 billion) prop to thirsty cotton farming heavily subsidised by the EU on the Thessaly Plains, is likely to go ahead following government circumvention of a Supreme Court declaration it was illegal and would be in violation of local, European and international laws on issues including water management, environmental assessment procedures and cultural heritage protection.
The report finds that in many cases there was little examination of alternatives to massive schemes, particularly in managing demand and promoting efficient water use in the mostly water scarce regions.
'Often it is going to make much greater sense to import water in extra food grown in wetter areas than to import water to grow food in a drier area,' said Geiger. 'However, non-technical solutions such as this trade in virtual water, less water intensive farming or more water efficient industries and cities tend to be neglected in planning directed at just supplying more water continually.'
Water planning in isolation is also likely to lead to unforeseen problems. The report details the numerous examples of poor integration with land use planning, particularly for agriculture and inadequate consultation on schemes leading to often severe local and regional conflict.
'Don't venture into interbasin transfers unless you have done your homework on impacts and alternatives,' Geiger said.
'Otherwise you could face serious planning deadlocks, operational shortfalls, unforeseen economic and environmental disruption, and expensive follow-up works that will only partly remedy the damage. If trends in water tables through climate change are not properly taken into account, the water planned for transfer might not be there any more in future.'