San Diego aims to fix a pollution problem by helping a Tijuana slum from Christian Science Monitor:
When it rains in Tijuana, it pours in San Diego. Runoff crosses the international border in gushes of floodwater, clogging everything in its path with dirt and debris.
A river, a wildlife-filled estuary, and the sea [plus nearby beaches] are all victims of this rainy-season menace, the product of a sprawling Mexican city where the poor often live without paved streets, running water, or sanitation.
Now, a cross-border team hopes to stem the tide of US-Mexican tensions and turn a Tijuana slum into an example of environmental activism. Their goal: Convince the community to devote its own time and effort to pave the roads in San Bernardo, a bustling neighborhood that becomes a bleak, muddy lake during heavy rains.
The story also includes a nice short audio segment.