One of the persistent challenges with cities like Maputo will always be the inability to pay for services, won't it? (The report you linked to notes the difficulty to pay for such a lump sum cost.)
Given the current situation, it seems like one has to subsidize (with financing help, at least) both the small-scale private sector and the households that would have to pay for the service.
At some point, is improved municipal tax collection and budgeting the way to go for a portion of this service? A tariff is noted at the end of the report as a longer term plan,(and perhaps I missed it) but I saw little further detail.