Shifts in spatial patterns of relative human water security threat after accounting for water technology benefits. Source: doi:10.1038/nature09440
The BBC has an interesting report that highlights that it's not just global warming-related changes to rainfall that threaten global water supplies, it the water infrastructure too. The areas of vulnerability for managed water supplies, as distinct from natural vulnerability, are surprising and include large parts of Eastern Europe and North America, as well as Asia.
The BBC report is based on an article in Nature that's worth reading.The article goes further than the report in making the link between underinvestment in water infrastructure and threats to freshwater biodiversity.
Prevailing patterns of threat to human water security and biodiversity.
As the figure above shows, the regions with the most threatened human water supplies and biodiversity loss are in Asia and Africa, a region that faces numerous water and biodiversity challenges.
Vorosmarty, C. J., McIntyre, P. B., Gessner, M. O., Dudgeon, D., Prusevich, A., Green, P., et al. (2010). Global threats to human water security and river biodiversity. Nature, 467(7315), 555-561. doi:10.1038/nature09440