ORI Sand Mining Survey
The 2019 survey shows that sand mining in estuaries is extensive, more than previously estimated. Seventy-two mining sites were located within or partly-within the province’s estuaries between 2001 and 2018.
2019 Survey Results
Mining activities ranged from small borrow pits < 1 000 m2 (0.1 ha) to extensive commercial mining operations > 90 000 m2 (9 ha). At most sites, there has been loss of riparian and floodplain habitats, substantial change to the estuary bed, banks and floodplain, and altered water flow to the sea where natural channels have been in-filled to create access roads or widened as banks are mined away.
The survey was extended to the lower reaches of the inflowing rivers (for approximately 10 km), because mining there would have likely impacts on the state of the downstream estuaries. A further 239 river mining sites were identified within 10 km of the coast. Overall, between 2001 and 2018, 37 different watercourses were mined for sand. Almost half of KZN’s 76 coastal rivers and estuaries are affected by sand mining.
Estuaries and Coastal Rivers Mined Between 2001 and 2018
Larger rivers with predominantly open estuaries tended to support permanent or semi-permanent larger mines over the surveyed period. Although, at least 30 of the smaller rivers/estuaries have been subject to some mining, particularly in and adjacent to the eThekwini Municipal Area.
Low, Medium and High Mining Pressure in Estuaries (left) and Coastal Rivers (right)
In these smaller rivers with intermittently closed estuaries, mining may have a disproportionately large impact on estuary habitat, and there is a high risk of cumulative effects when estuary mouths are closed off from the sea. The number of active sand mines in estuaries in 2018 suggest that mining pressure on these smaller systems may be increasing relative to previous years.
Sand Mining in Different Estuary Types 2001-2018 (left) and 2018 (right)
