Rainwater harvesting system for a sustainable water supply for the poor on Merbau island

Difficulty in meeting one's basic daily needs such as clean water in order to fulfill a healthy, clean and productive life is a significant problem for people living on remote islands. Rainwater is the only source of clean water for the community on Merbau Island because of the low quality of the surface and groundwater resources. The majority of Merbau Island is covered by peat and lowlands; hence the rainwater that falls on the land surface is generally contaminated with peat water, which tends to be more acidic. Frequent rainfall at the location produces an abundant volume of water that is sufficient enough to meet the collective household daily demand for clean water. However, the community is not able to provide a large rainwater harvesting facility that can minimize the loss of rainwater into the rivers or seas. This study aimed to obtain data on the field conditions used as the basis for planning RWH systems for domestic needs so as to meet the need for sustainable clean water on Merbau Island. The results show that the highest rainfall recorded in 2013 was 3,164.3 mm. Such an amount of rainwater can fulfill the daily clean water requirements for each household on Merbau Island. The population of poor people on the island is approximately 44%, which results in around 73% of people not having an adequate rainwater harvesting system. The average roof area data, the number of family members and the type of roof, being 213 m(2), 6 people and zinc (0.9) respectively, using the Rain Cycle v2 software, obtained the result that a 12 m(2) tank is needed to meet the need for clean water throughout the year.