The Water Utilities Corporation (WUC) was forced to intervene recently after the contractors of the P1.7 billion Boatle-Gaborone dual carriageway project dammed off a key river feeding Gaborone Dam.
Metsemaswaane River is one of the three main sources of inflows to Gaborone Dam. The River crosses the A1 to Lobatse just near Mokolodi, where it flows to meet with the Taung and Notwane Rivers, that feed the Dam.
The P1.7 billion project, which started in March 2017 and is due for completion in March 2019, involves the expansion of the key stretch of the A1 to a dual carriageway and associated works.
From the latter part of last year, motorists using this portion of the highway began reporting that the contractor had dammed off the Metsemaswaane River towards the west and was pumping the water out for road construction purposes.
The damming off was reportedly done in October with the approval of ministerial water authorities, who it is understood, were comforted in their decision by the dry spell of the period.
“The river was cut off with sand, gravel and rocks while the water was pumped for construction purposes. The approving authorities believed the impact would be minimal because the rain season was not yet underway and in any case, Gaborone Dam was at healthy levels.
“We saw this obstruction everyday and wondered whether there had been proper planning around it,” Leslie Segokgo, a motorist who uses the road daily, said.
He added: “It is not
This week, the WUC told Mmegi that it had intervened in the matter.
“The contractor had constructed the coffer dam in the section of the river on the basis of a water right that they had been granted by Water Apportionment Board,” acting corporate communication manager, Khumo Mugibelo said.
“WUC has successfully queried the water right and it has since been withdrawn. The contractor subsequently applied for a nearby connection and has been supplied with a metered connection at the nearby Notwane Dam.
“The contractor is paying a bill on a monthly basis.” Mugibelo added that the damming of a river within a dam area can “affect or delay flows” into the river when it rains, thus losing the retained water to evaporation.
Efforts to secure comment from the Roads Department were fruitless as enquiries went unanswered. However, officials there, speaking off the record, said coffer dams were standard practice where road construction intersected rivers.
After a prolonged and unexpected dry spell, the country began receiving rains in late January. Water levels at Gaborone Dam dropped from 77% to 75% during January, but have since recovered to 76%.