I find that this cannot be true of water scarce countries in our world's desert areas who have quite healthy GDPs (based on petroleum). I also think a country's GDP depends on many factors, water perhaps being one, but not necessarily a central one. I shudder to think why the Bank is pushing this idea - the last of the world's great wild stretches of rivers are located in developing places where country governments are strategizing how they can improve their GDPs.
I err on the side of caution: always, always attempt to use critical thinking with these ideas that are placed before me as common truths until I find evidence to swing me in one direction or another...
What I know: China is leading the world in hydropower development by a significant amount both at home and abroad. The World Bank has accordingly ramped up their hydropower portfolio after years of reallocating funds for large water projects amid protests from people in the late 1900s and the World Commission on Dams Report. That report, in 2000, that pointed out how much cost dams cause to local people. Further research (by Brian Richter, et. al 2010) claims that the WCDR was conservative in their estimates. When the topic was brought up during a dinner one night, two years ago, a former WB employee leaned over and said to me, "you can look into this, but no one will talk to you about it." Sinister, why the secrecy?
What I think: the World Bank is building up a story to validate their aggressive plans to develop the world's last remaining wild resources. If there is money to be had, the World Bank will be there with bells on. They claim to serve community interests, but they continually serve select members of country government interests while displacing high numbers of people, rendering them landless and dependent on an already taxed system. They put countries into further debt for projects that benefit the few, and perhaps the national GDP, if the host government is lucky. I have yet to see a World Bank project, a significant one, that really improves society. They do build schools and contribute to the medical sector in some select places...say they are contributing to combat climate change in various ways (don't look to closely as to how), but at the end of the day they are a bank, not a service outfit. They want you to show them the money - even if it breaks the lives, identities, and dignity of people living in conditions with little choice to begin with. The horror.