Civil Engineering July 2021 | Vol 29 No 6

Water Eng i neer i ng T he Mhlabatshane Bulk Water Supply Scheme (BWSS) is owned and operated by Umgeni Water, one of the top suppliers of bulk water to communities in South Africa. The maximum yield of the Mhlabatshane Dam serving Phase 1 of the Mhlabatshane BWSS has been reached and Umgeni Water is now implementing Phase 2, where water from the Mzimkhulu River will augment the water from the dam, enabling the capacity of the associated water treatment works to be increased from 4 Mℓ/d to 12 Mℓ/d. The location of the weir on the Mzimkhulu River was determined by Stellenbosch University using model- testing to find the best place to minimise the intake of the river’s high sediment load during the summer rainfall season. During the winter months when there is not enough run-of-river yield, the Mhlabatshane Dam will provide water. The selected weir location is in the middle Kyle Holmes Project Engineer – Design Lead Naidu Consulting Graham Simpson Pr Eng Project Principal – Specialist Naidu Consulting Richard Jones Project Engineer – Digital Lead Naidu Consulting Novel concept and digital twin for the Mzimkhulu River Abstraction Works design The project team working on the Mzimkhulu River Abstraction Works for Phase 2 of the Mhlabatshane Bulk Water Supply Scheme is making use of a digital twin to enable better design and project management. Civil Engineering July 2021 35 The best solution incorporated a bridge onto the abstraction works’ top deck