I remember hearing that the Aswan Dam contributed to the spread of schistosomiasis, because the snails that are carriers of the parasitic worm live better in … whatever circumstances it is that the dam causes.

Giant infrastructure projects are less in vogue as forms of aid, and for good reason. As lots of people have pointed out, the global donor-aid-industrial complex can be as much about recolonialization and maintaining control (and benefiting the donor country) as it is about actual aid.