An Analysis of Household Rainwater Harvesting Systems in Falelima, Samoa

Since global commitment to the Millennium Development Goals (MDGs), there have been major gains in reducing the percentage of the world's population without access to improved water supplies. However, as more people gain access, the difficulty of expanding access to the remaining population increases as the easier solutions are completed, and areas of greater water stress remain. In the Pacific island nation of Samoa, access stands at approximately 90%, but the remaining 10% of the population resides in areas of limited surface or ground water resources. Many of these communities have turned to rainwater harvesting as a supply source. The village of Falelima, Samoa on the island of Savai'i is one such example. Residents meet their water needs through rainwater harvesting, but the ability to collect and store rainfall varies greatly between individual families. This paper examines the rainfall collection areas and storage volumes needed to provide various service levels throughout the year. A simple model is used to produce reliability design curves for the village that can allow users or outside agencies to determine how the addition of system capacity will increase water availability to a certain proportion of families. Finally, outcomes from a recent construction project are evaluated, and recommendations are made for further work to provide all families with a minimum level of service