Rainwater Harvesting Storage Methods and Self Supply in Uganda

Self supply is an emerging approach to water supply which focuses on fostering household investment in incremental improvements to their water sources. When successful, it can lower costs and increase sustainability by offering users a larger share of ownership in their own supply, and harnessing the already existing strengths of a community rather than trying to impose an external perspective. In addition to well upgrading and source protection, one of the key self supply areas is rainwater harvesting. Uganda has a diverse selection of rainwater storage options, but many of them are scattered and disparate. The objective of this study was to create a comprehensive collection of well-established Ugandan rainwater storage options, and to demonstrate the geographical disparities in availability, particularly for Rakai District, where the author lived and worked as a Water and Sanitation Engineer for two years. Data was gathered by interviewing key stakeholders in rainwater harvesting at the national, regional, and district level in order to gather their collective knowledge in rainwater harvesting storage techniques. In order to understand the availability and pricing of manufactured products, a survey of Rakai District hardware stores determined the prices and range of volumes at which different manufactured products were available. The study found 11 distinct technologies widely used for rainwater storage: three informal or traditional, three manufactured, and five built-in-place by skilled artisans. The traditional/informal technologies consisted of clay pots, pots and basins, and brick mortar tanks. The manufactured products were plastic tanks ranging from 60 to 24,000 liters, corrugated iron tanks, and 55-gallon metal drums. The built-in-place tank technologies were mortar jars, tarpaulin tanks, ferrocement tanks, partially below ground ferrocement tanks, and interlocking stabilized soil brick tanks. The study also found that while the manufactured products are well distributed, built-in-place options have not spread beyond where they were originally introduced by NGO\u27s trying to promote certain technologies. With regard to costs, tanks with storage volume less than 1,000 liters had costs that ranged from 182 to 724 UGX/liter, with small plastic tanks being least expensive. For volumes between 1,000 and 10,000 liters, costs ranged between 42 and 350 UGX/liter, with tarpaulin tanks providing the largest storage per unit cost. Above 10,000 liters of storage, tanks ranged from 35 to 341 UGX/liter, with tarpaulin tanks again ranking first by cost per unit volume. In order for self supply to flourish, these technologies need to be implemented in such a way that fosters a thriving private sector and independent uptake of rainwater harvesting. This research provides a starting point by laying out the technologies, costs, and volumes available