What do you see? A formidable band of rain, located in the intertropical convergence zone. Here, precipitation levels are high and constant. Most of the world's rain falls in the oceans, inaccesible to man.
My idea: put huge plastic platforms in these ocean zones, of say 10 square kilometres. The
platform will float and catch this relatively clean rainwater.
Catch the drinking water in huge plastic bags (fresh water floats on salt water), and ship to your nearest destination.
The platform can be gently towed to other locations and follow the rain, to optimize the catch and to minimize ecological damage.
For some regions, this may be a cheaper and cleaner way of getting to fresh water than either desalination (which is quite polluting), rerouting rivers and building canals or pipelines, or tapping rivers and shipping the water (like some are planning to do).
The platform has other advantages: it doesn't pollute shorelines, it can't be seen from ashore, and it's not a likely terrorist target (which other water infrastructures are, especially dams).
This may well be the equivalent of the offshore oil industry, since some are already calling drinking water the blue gold of the 21st century.