DAR ES SALAAM, Tanzania — For 50 years, foreign do-gooders who wished to improve access to water in Africa went about it basically the same way. They’d dig a well or build a water pump for free. Then they’d hand off the project to the local community — leaving the responsibility, and the financial burden, of maintaining it up to them.

And yet, for the same 50 years, that model hasn’t worked. Wells run out of water. Fuel for electrical generators to pump water becomes expensive. Pipes spring leaks. And rural communities where most people live on less than $2 a day can’t come up with the money to fix it all.

So perhaps it is no surprise that aid money has not solved Tanzania’s notorious water crisis. But even as the $1.4 billion Water Sector Development Programme (WSDP) showed signs it was not working after five years, the World Bank and other organizations provided even more money without first investing in identifying new solutions to old problems.

Read Part Four of a four-part series produced by The GroundTruth Project