Possible mechanisms that might have initiated the failure of Slimes Dam No. 1 at Bafokeng are examined and the conclusion reached that the most probable trigger to the event was piping through the wall. This catastrophic failure highlights the fact that slimes dams are important and sometimes hazardous structures which demand proper design, monitoring control and careful maintenance.
Die moontlike meganismes wat daartoe gelei het dat Modderdam Nr. 1 te Bafokeng misluk het word ondersoek en daar word tot die slotsom gekom dat pyping deur die wal die waarskynlikste oorsaak van die mislukking was. Hierdie katastrofiese mislukking beklemtoon die feit dat modderdamme belangrike strukturc is wat soms gevaarlik kan wees en wat 'n behoorlike ontwerp, aanhoudende beheer en sorgvuldige onderhoud verg.
Bafokeng South Mine, one of Union Corporation's Impala group of platinum mines, lies in Bophuthatswana, about 20 km north of Rustenburg in the western Transvaal. Platinum group metals are extracted from ores of the Merensky reef mined at relatively shallow depths. The hard mined ore is milled to rock flour for extraction of the precious metals and the residue, mixed with water, is pumped to tailings or slimes dams from which any recovered water is recirculated. South African practice for the construction of slimes dams was developed on the Witwatersrand for the disposal of gold mining slimes and, with minor modifications, has been adopted on the platinum mines.
During the early morning of Monday, 11 November 1974, heavy rain fell in the Rustenburg area. Reports from raingauges in the vicinity differed widely but it was estimated that at the Bafokeng mine 75 mm of rain fell between 02h00 and 04h00.