Bittersweet rain forecast for parched Gaborone Dam
Mbongeni Mguni | Wednesday September 10, 2014 14:51
Met Services director, Thabang Botshoma, dashed hopes of early relief for the 500,000 or so residents of Greater Gaborone when he unveiled the 2014/15 seasonal rainfall forecast indicating mixed fortunes for the southern and eastern regions.
Botshoma’s forecast comes as Gaborone Dam reaches its lowest point in its 50-year history at under nine percent. While the Ministry of Minerals, Energy and Water Resources expects the Dam to fail next month, this could happen anytime as the water continues to recede below the level at which the pumps can tap into it. As Gaborone Dam faces its first failure, the Met Services Department expects the first rains only by mid-November and also forecasts that the whole country will have a shortened rain season.
“The last rainfall season was a good one for most of Botswana but we all know very well the Gaborone Dam story and what happened in terms of rainfall over the south-eastern parts of the country,” Botshoma said.
“We also know that the 200 plus dams downstream are being blamed for the Gaborone Dam situation. It is expected that Gaborone Dam would dry up next month.”
Botshoma said researchers from the University of Botswana and the Southern African Science Service Centre for Climate Change and Adaptive Land Management, were studying the impact of the dams on Gaborone Dam’s inflows.
The seasonal rain forecast indicates that between October and December, the Greater Gaborone area will receive above-normal to normal rain, meaning rainfall amounts could be beyond 190 millimetres over the period.
During the second half of the rain season, between January and March, however, the Greater Gaborone area will have “an increased likelihood” of below-normal to normal rains.
“The onsets of rains are expected in mid-November for most parts of the country,” reads the seasonal forecast.
“A shortened rainfall season is expected and the rest of the country will start to experience a deficit of rains in March 2015.”
Should Gaborone Dam fail, the region will be entirely dependent on the North South Carrier and upcoming boreholes in Masama and Ramotswa.
The Ministry of Minerals, Energy and Water Resources says it has fortified the problematic 26-kilometre stretch along the Carrier which was previously the source of many supply interruptions.
Plans are also underway to hasten the North South Carrier 2 to bring water from Dikgatlhong Dam to the South, while also installing an additional pump station in the existing North South Carrier to increase water flow from Letsibogo Dam.