River sand levels dangerously low – manufactured sand the solution?
Levels of river sand – an essential commodity in infrastructure development and the building trade – are at an all-time low.
Findings by the Botswana Geoscience Institute (BGI) from recent research conducted on the local river systems reached a worrying conclusion – river sand is literally running out.
Fortunately for the construction industry, an alternative has been found in Manufactured Sand, which is created from source rocks such as sand stone and granite rock found across the country.
Having identified source rocks in Molepolole, Ntlhantlhe, Kgomiokasitwa, Mmankgodi, Kgatleng area, the Serowe/Palapye region, Francistown, Ghantsi, Maun and Kasane, BGI are optimistic that as well as providing the much-needed sand, the quarries will create employment for local communities, especially in the unskilled departments.
Indeed, BGI’s Chief Economic Geologist, Dr Gomotsang Tshoso expects the quarries to hire up to two hundred people each.
Speaking at Monday’s media tour of the experimental wall built from manufactured sand using the different types of bricks available from local brick manufacturers in Lobatse, Tshoso claimed the quarries have enough source rock to last for more than 25 years.
Meanwhile, BGI Senior Geologist, Ngie Wantlo revealed that the river sand’s depleted levels have forced sand miners to dig up the ‘fossil sand’ which makes the river banks.
“This sand should not be mined as it is the structure that gives the river its shape,” he warned, adding that the excessive sand mining they observed in some places has deepened the riverbed by over twelve metres.
He stressed that the low depths were dangerous as animals and people run the risk of death in cases where they fall into pits.
However, Wantlo noted that the problem could be alleviated by introducing manufactured sand as a substitute to river sand.
“Manufactured sand has the added advantage that one does not need pit sand, another expense linked to the use of river sand,” highlighted Wantlo.
BGI Manager Surveys, Mojaboswa Koketso stated that the findings prompted the newly established BGI to seek alternatives to natural sand as the harvesting of sand has become detrimental to the environment.
“Excessive natural sand harvesting has caused environmental degradation that will take years to replenish,” he predicted ominously.