The following are estimates of the amount of money (in trillions of dollars) each area of the globe will need to invest between 2005-2030 in order to maintain their fresh water infrastructure:

1. 9.0 Asia/Oceania
2. 5.0 South/Latin America
3. 4.5 Europe
4. 3.6 U.S./Canada
5. 0.2 Africa
6. 0.2 Middle East

These estimates were found in Peter Rogers, "Facing the Freshwater Crisis", Scientific American, Aug 2008. Peter cites decreased government investments since the late 1990's, increased population, global warming, and increased affluence as some of the major factors stressing our freshwater infrastructure. The numbers for Africa and the Middle East probably reflect their investment ability rather than what they actually need which would depend upon assistance from more affluent countries. If you are looking to invest in freshwater conservation and infrastructure then it might be interesting to take a deeper look into the specific needs of these different areas. The article provides a list of books on the topic that you can consult to go deeper.