El Niño Update – December 2023
By Mlungisi Shabalala, 01 January 2024
The latest assessment of the El Niño Southern Oscillation (ENSO) signal shows that the key oceanic and atmospheric variables in the central-eastern equatorial Pacific Ocean remain consistent with the ongoing strong El Niño conditions. Almost all climate models suggest sustenance of the strong El Niño signal throughout the summer season into early autumn (see Australian Bureau of Meteorology and International Research Institute for Climate and Society for detailed information on climate models).
Based on the sea surface temperatures in the Pacific Ocean (ENSO zone of interest), the ongoing El Niño cycle may potentially be amongst the four strongest El Niño cycles on record. El Niño conditions typically result in below-normal rainfall in South Africa. However, the impact of the ongoing El Niño cycle on rainfall has, so far, been minimal.
During December 2023, uMngeni-uThukela Water’s area of operation received relatively normal to above-normal rainfall, as suggested by the October 2023 climate model predictions. As a result, most dams were above full supply capacity at the end of December 2023, similar to the end of December 2022.
| Site Name | Today (%full) | Last Year (%full) |
| Henley Dam | 110 | 110 |
| Hazelmere Dam* | 82 | 523 |
| Umzinto Dam | 102 | 100 |
| Inanda Dam | 104 | 108 |
| iMvutshane Dam* | 71 | 85 |
| Mearns Dam | 108 | 129 |
| Nagle Dam | 101 | 96 |
| Spring Grove Dam | 73 | 102 |
| Nungwane Dam | 101 | 101 |
| Albert Falls Dam | 99 | 107 |
| Home Farm Dam | 117 | 106 |
| Olifantskop Dam | 105 | 114 |
| Ludeke Dam* | 76 | 75 |
| Midmar Dam | 92 | 102 |
| Mhlabatshane Dam | 101 | 101 |
| Spioenkop Dam | 102 | 101 |
| Wagendrift Dam | 102 | 105 |
| Goedertrouw Dam | 101 | 102 |
*Dam levels managed for safety reasons.
Although most global climate models suggests that an El Niño cycle is currently underway and will be sustained throughout the summer season, the latest model predictions indicate a likelihood of above-average rainfall in the central and north-eastern parts of the country (including UUW’s operational area) throughout the summer season. However, stakeholders are encouraged to conserve water resources as we approach mid-summer, which is typically characterised by high temperatures. Water users are also encouraged to remain alert and follow weather updates (as well as warnings) from the South African Weather Service. uMngeni-uThukela Water will issue an update at the end of January 2024.
