The maintenance mentioned may be a more basic, procedural one than a structural one. They seem to be relatively simple.
«When the nets wear out, the villagers will have to replace them at a cost of 100,000 pesos each» - that's ~100€|USD.
I am not sure where you read that «biggest implementation hurdle», if it was the sentence «The question is not whether the fog collectors work but who’s going to provide and maintain them», I do not read that so strongly.
> Earlier attempts to turn the mist into usable water failed. In 1990 fog nets at Chungungo, a fishing village north of Los Tomes, captured 8,000 litres a day. Villagers argued about how to share responsibility for maintaining the atrapanieblas.
It sounds like the nets worked, and the only negative element of the project described in the article that could account for the failure is the issues around maintenance. And then it's mentioned again in the context of open "questions" of the current project. But maybe the emphasis wasn't intended by the author, I may be reading too much into it.
They started attempting to obtain water from fog in the '50s, until in the '90s the first working atrapanieblas were successfully deployed. "The villagers regarded it as a collective critical success and conversely a common responsibility".
According to an article I posted in the root,
> Un panel captaniebla es económico. Uno de 40 metros cuadrados está en el orden de los 1.000 a 1.500 dólares
It also says that the most common nets are made of plastic: so, there will be different standards and costs.