In many developing nations, water shortage is a significant issue. Rainwater may be used as a source of drinking water depending on the amount of precipitation. Furthermore, effective management may help alleviate water and food shortages in some of these areas. Rainwater harvesting (RWH) is a technique for efficiently collecting surface runoff during rainy seasons. RWH systems should be built on local talents, resources, and equipment to support such innovations. The majority of developing nations are categorized as water-scarce, with low irregular rainfall, resulting in a high risk of droughts, intra-seasonal dry spells, and frequent food insecurity. The majority of rain occurrences are intense, typically convective storms with very high rain intensity and significant spatial and temporal rainfall variability. The rainfall-to-evaporation ratio is often poor. Rainwater harvesting may then be utilized for rain fed agriculture or domestic water supply. Rainwater, however, may be contaminated with germs and dangerous substances, necessitating treatment before to use. Pollution may be reduced using slow sand filtering and solar technologies. Membrane technology may potentially be used to purify water to ensure that it is safe to consume.