12 Jan 2025

While most of the country’s 10 dams managed by Water Utilities Corporation (WUC) are showing rising water levels, Gaborone Dam remains critically low at 36 per cent and it is projected to sustain the city’s water supply for 14 months without any further inflow.

This was stated by the corporation’s CEO, Mr Gaselemogwe Senai during a briefing to update members of the media on the current state of dams nationwide in Gaborone on Friday.

Mr Senai explained that Gaborone Dam constructed in 1967 and expanded in 1984 had played a crucial role in supplying water to Gaborone and surrounding areas. He said over the years, the dam’s performance had been impacted by factors such as rainfall variability, increasing demand, and climate change.

Mr Senai stated that periodic droughts have led to declining water levels, highlighting the severe dry spell of 2005- 2006, when the dam’s level dropped to 16 per cent, only to rise to 87 per cent within three days in February 2006.

He also referenced the significant water crisis from 2010 to 2016, particularly the drought from 2013 to 2016, which saw the dam’s water level drop to less than two per cent.

“This crisis led to water rationing and a higher reliance on the North-South Carrier pipeline for supply,” he said.

However, Mr Senai said 2017 came with improved inflows, boosted by Tropical Cyclone Dineo, to allow for some recovery, while rainfall in subsequent years helped maintain a seasonal fluctuation in water levels.

Despite those improvements, Mr Senai cautioned that climate change, evaporation losses and growing demand continued to challenge the dam’s long term sustainability.

He noted that there were about 200-230 small dams surrounding Gaborone Dam, and said contrary to concerns that they might be impacting the flow of water, they were essential to the ecology and sustenance of Gaborone Dam as they trapped silt and sand before it reached the dam.

“When small dams hold 10 per cent of Mean Annual Runoff (MAR), catchment MAR declines by 8–10 per cent, while there has been a reduction in the MAR into Gaborone Dam, the small dams serve as silt trap, reducing the rate of siltation,” he explained.

He further noted that those mini-dams were legal, as they were granted water rights through relevant government departments at the time of their construction.

“Some are used for agricultural purposes and support farming community,” he said.

Mr Senai expressed hope that Gaborone Dam water level would improve, particularly with Tropical Cyclone Dikeledi which was expected to bring heavy rainfall and potentially increasing inflows into the Gaborone Dam catchment area.

“The cyclone may extend into the Gaborone Dam catchment,
increasing inflows,” he said. ENDS