According to model assessments by the International Research Institute for Climate and Society, the El Niño Southern Oscillation (ENSO) signal remains in an El Niño state for the April-May-June (AMJ) period. Therefore, an El Niño advisory remains as oceanic and atmospheric indicators in the central-eastern Pacific Ocean continue to align with the diminishing El Niño event. The multi-model based forecasts suggest that neutral conditions will prevail from late autumn into winter, with a high likelihood for La Niña conditions to develop towards the end of winter.
Figure 1: Mid-April ENSO Forecast by IRI.
uMngeni-uThukela Water’s area of operation received relatively normal to above-average rainfall during April 2024. As a result, all dams managed by uMngeni-uThukela Water remained in relatively high storage levels during April and were at full supply capacity on 01st May 2024. Only the Ludeke, Hazelmere, iMvutshane and Pongolapoort Dams were below full supply capacity as these are managed at relatively low storage levels for safety reasons.
Table 1: Dam levels as % of full supply capacity in UUW and some DWS-managed dams on 1st May 2024, compared to the previous two years.
| Site Name | Dam Level (% of full supply capacity) | ||
| 01 May 2024 | 01 May 2023 | 01 May 2022 | |
| Mearns Dam | 108 | 103 | 117 |
| Spring Grove Dam | 101 | 99 | 101 |
| Midmar Dam | 100 | 97 | 101 |
| Henley Dam | 105 | 105 | 107 |
| Albert Falls Dam | 101 | 99 | 102 |
| Nagle Dam | 100 | 95 | 102 |
| Inanda Dam | 101 | 101 | 103 |
| Home Farm Dam | 101 | 100 | 113 |
| Nungwane Dam | 101 | 101 | 102 |
| Umzinto Dam | 100 | 99 | 100 |
| E.J. Smith Dam | 100 | 98 | 100 |
| Mhlabatshane Dam | 101 | 100 | 101 |
| Ludeke Dam | 46 | 65 | 100 |
| Hazelmere Dam | 84 | 56 | 53 |
| iMvutshane Dam | 61 | 62 | 90 |
| Goedertrouw Dam | 98 | 100 | 99 |
| Pongolapoort Dam | 87 | 84 | 89 |
| Olifantskop Dam | 104 | 102 | 110 |
| Spioenkop Dam | 100 | 99 | 100 |
| Wagendrift Dam | 101 | 100 | 102 |
| Woodstock Dam | 100 | 95 | 101 |
The high storage levels indicate that there is no risk of non-supply for UUW’s customers in the short-term. However, the beginning of May is a critical period for water resources planning in UUW’s area of operation, as it marks the onset of the dry season. Therefore, it is important for water users to conserve water during this period. uMngeni-uThukela Water will continue to monitor the ENSO signal, as well as developments in SA’s neighbouring countries, i.e. Malawi, Zimbabwe and Zambia, who are currently experiencing an El Niño-induced drought. The next update will be issued at the end of May 2024.
