The correct supply and storage of rainwater is a valid option to improve access to quality drinking water.
Rainwater can be a solution if it is collected safely and efficiently. It will depend on the amount of water that can be stored and its quality.
A collection surface that is non-porous and inclined, a seamless and stable channel and a storage tank are necessary. Roofs and downspouts, being outdoors, are susceptible to contamination, while storage by its very nature tends to lose properties and generate microbes. Therefore, rainwater must be treated or filtered before consumption.
Another thing to keep in mind is that we depend on an uncertain and different meteorological phenomenon in each region of the world. There are desert areas where it barely rains, and there are others where it does so seasonally, which makes planning difficult.
The cost of these systems is reduced in terms of materials, machinery and labor, making it a commonly used solution in many rural regions of Africa and Latin America.
It requires periodic maintenance of cleaning the roofs, repairing structures and disinfecting tanks.
Water will always be available in the raining season and when it is not raining, whatever has been stored. It is very common for deposits to run out when there is a drought.
From an environmental point of view, it is the most sustainable solution, as it does not erode the soil, transport water or use energy.
It is the purest water with the least chemical contamination. It lacks mineral contributions and its conductivity is very low.