A rural school in Uganda is setting an example with its off-grid water system

Riverside High School, a residential institution in the village of Mbazzi, Uganda, stands as a remarkable example of self-sufficiency in water management in a world increasingly impacted by climate risks. Spread across 130,000 square metres, the school houses 670 residents year-round. The campus harvests approximately 97,124 cubic metres of rainwater annually, which is nearly 40 per cent of the water supplied in Kampala, according to the International Water Association source.

Mbazzi village is located 17 kilometres from Kampala, in the Mpigi district, which lies south of the central region of the country. As per the World Bank’s Climate Knowledge Portal source, Mpigi district receives an average annual rainfall of 1,508 millimetres, based on a 25-year average from 1998 to 2022.

Central and southern Uganda experience two rainy seasons each year, from March to May and September to December, collectively providing about nine months of rainfall. This makes it feasible to store and utilise harvested rainwater for most of the year.

Currently, the school harvests rainwater from the rooftops of most of its buildings, covering an area of 1,320 square metres. It harvests water from 75 per cent of its roof area, storing it in five large cement tanks with capacities of 100 cubic metres, 500 cubic metres, 250 cubic metres, 100 cubic metres and 70 cubic metres, together holding a total of 1,020 cubic metres.

In addition, there are six small PVC tanks of 5 cubic metres each, providing an extra 30 cubic metres. Thus, the school can store approximately 1 million litres (1,050 cubic metres) of rainwater at any given time during the seven-month rainy period.

According to the headteacher, Fred Ssembeguya, the school’s daily water requirement is 8,240 litres, and its annual need is almost three times the amount of rainwater stored. Ssembeguya added that during the rainy season, the school regularly uses water from the tanks, with the daily consumption replenished by the frequent rainfall. The stored rainwater is utilised for drinking, cooking, handwashing, flushing, mopping, and irrigation, as well as in the school laboratories. For drinking purposes, the water is filtered through UV systems placed at two points on the campus.

During the dry season, the school relies on a borehole, which extracts groundwater from a depth of 21 metres. However, the school is not yet utilising its full rooftop potential, said Walude Mtwalib, research & development engineer at the Uganda Muslim Rural Development Association, a non-profit organisation based in Uganda. If the entire rooftop area were harvested, the school could potentially reduce its dependency on the borehole, Mtwalib added.

The school aims to stand out in the region not only by conserving water but also by growing its own food. In addition to wheat and millet, 80 per cent of the food and poultry consumed on campus is produced locally. Organic waste from the school is used to feed the chickens.

According to the National Water Resources Assessment Report 2019, Uganda is expected to increase its reliance on groundwater for various uses. Over the coming years, groundwater dependency is projected to rise by 30 per cent in certain areas of Uganda, including the Mpigi district. Therefore, it is imperative for the school to maximise its rainwater harvesting potential, expanding rooftop collection and using other permeable areas for groundwater recharge.