What solutions do you see for the vast migration to the cities of least industrialized nations?

Thousands of people whose families have historically resided in rural areas within their countries, are now flocking to the cities (of the least industrialized nations). However, many of those who move to the cities do not have the funds to live well in the cities themselves. Rather they live in constructed housing areas, that lack running water, schools, proper buildings, doctors, transportation, etc.  What solutions do you see for the vast migration to the cities of least industrialized  nations?