Curitiba in Brazil is a city with limited resources but with great resourcefulness!
To battle the problem of floodings, but without the finances to build dams, they built beautiful parks. Not only did this take care of the flooding issues but it improved the lives of the people previously living in favelas around these problematic areas. These people were payed to move to other areas with better quality housing increasing their living standard. This was payed for by the increased land prices around the parks, increased taxes were taken out and the parks opened up for new businesses to start up. It turned out that this approach was five times more profitable than building dams and embankments.
Sounds too good to be true? Nope, have a look for yourself, watch A Convenient Truth: Urban Solutions from Curitiba, Brazil. (doc)