The uMngeni-uThukela Water (UUW) has recommended that eThekwini Municipality prioritise reducing water losses and improving the efficiency of its existing water distribution network rather than investing in new package water treatment plants to address ongoing water supply challenges.
The recommendation forms part of a preliminary feasibility study presented to the municipality's Executive Committee (EXCO) on Thursday.
The municipality had commissioned the study to assess the feasibility of establishing package water treatment plants in communities experiencing prolonged water shortages.
According to UUW, water demand management interventions would deliver faster, more sustainable, and cost-effective benefits than constructing new supply infrastructure.
The utility said demand management interventions would enable the municipality to recover significant volumes of non-revenue water, making more water available to consumers without increasing current bulk water supply.
“These interventions can also be implemented over a shorter period and at a substantially lower cost than developing new water supply schemes,” the municipality said in a statement following the meeting.
While acknowledging that package treatment plants could provide interim relief in some communities, UUW warned that they would require substantial capital investment and may not represent the most cost-effective long-term solution.
For the proposed package plant serving the Qadi area in Umzinyathi, UUW estimated that a 10-megalitre-per-day (ML/day) plant would cost about R1.2 billion, while a 30 ML/day facility would require an investment of about R3.5 billion.
The utility estimated that water produced by the plant would cost approximately R53 per kilolitre over 20 years. The estimated monthly capital unit charges would amount to approximately R12.6 million for the 10 ML/day plant and R37 million for a 30 ML/day plant, excluding applicable bulk water tariffs.
UUW also advised that the provincial Department of Water and Sanitation is unlikely to approve additional water abstraction above the existing licence for the proposed Qadi scheme. Any increase in abstraction would require a corresponding reduction in water drawn by the Wiggins and Durban Heights water treatment works.
The utility further noted that the long-term viability of the Qadi plant may be limited by the planned commissioning of the uMkhomazi Upper Dam from 2034, which is expected to significantly increase bulk water availability to the municipality.
The feasibility study also assessed proposed package plants for Mfume, Craigieburn and Umbumbulu.
The estimated capital cost for the Mfume plant is approximately R650 million.
For Craigieburn and Umbumbulu, UUW said construction would likely be completed only after major regional bulk water projects become operational. The Lower uMkhomazi Dam is expected to begin supplying southern areas of eThekwini from 2029, while the uMkhomazi Upper Dam is projected to supply the entire municipality, including Umbumbulu, from 2034.
UUW also warned that a package plant at Umbumbulu would draw from the same source as the Amanzimtoti Water Treatment Works, potentially reducing water availability to areas already supplied through Amanzimtoti.
The utility added that its ability to undertake large capital projects is constrained by reduced tariff increases, limited borrowing capacity and the shortened economic lifespan of projects that could be superseded by larger regional water schemes.
“EXCO noted the preliminary findings and agreed that the feasibility study should be finalised before any decisions are taken regarding the available options. UUW will return to EXCO to present the completed study together with its final recommendations,” the municipality said.
Progress in reducing 2-Methylisoborneol
Meanwhile, the UUW reported that interventions at the Wiggins Water Treatment Works have significantly reduced 2-Methylisoborneol (2-MIB) levels, the naturally occurring compound responsible for the earthy taste and odour detected in water supplied to parts of eThekwini in recent months.
According to UUW, the problem resulted from increased algal activity in Inanda Dam, which affected the quality of raw water entering the treatment works.
To address the issue, the utility has strengthened water quality monitoring from the catchment to consumers, implemented multi-level abstraction to draw water from lower levels of the dam where appropriate, and applied advanced treatment chemicals to remove taste and odour compounds.
UUW said ongoing daily monitoring confirms that treated water remains safe for human consumption and continues to comply with the South African National Standard for Drinking Water. – SAnews.gov.za
