El Niño Update – November 2023
By Mlungisi Shabalala, 30 November 2023
uMngeni-uThukela Water (UUW) continues to monitor the El Niño Southern Oscillation (ENSO) signal and its potential impacts on water resources operated by UUW. The latest climate model updates indicate that the ENSO remains in an El Niño state (Australian Bureau of Meteorology; International Research Institute for Climate and Society). According to the International Research Institute for Climate and Society, the probability of the sustenance of El Niño conditions remains high (100%) throughout the summer season (DJF).
Due to the above-normal rainfall received in UUW’s area of operation during October 2023, most dams remain at a relatively high storage levels. However, it is important to note that, on 30th November 2023, most dams were at lower storage levels than compared to a similar time last year (see dams in the Mooi-Mgeni System in the table below).
| Site Name | Today (%full) | Last Year (%full) |
| Mearns Weir | 89 | 115 |
| Spring Grove Dam | 69 | 101 |
| Midmar Dam | 79 | 99 |
| Albert Falls Dam | 92 | 97 |
| Nagle Dam | 86 | 98 |
| Inanda Dam | 101 | 102 |
Although most global climate models suggests that an El Niño cycle is currently underway and will be sustained throughout the summer season, there is a significant level of uncertainty on the potential impact of the current El Niño state on South Africa’s rainfall. El Niño conditions typically result in below-normal rainfall in South Africa, however, 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. The average air temperature, on the other hand, is expected to be above-normal for most parts of the country, a typical characteristic of El Niño conditions. High temperatures may result in high evaporation losses, posing a threat to water resources availability. Therefore, it is essential for water resource managers to closely monitor the status of water resources as El Niño conditions develop.
Water users are advised to practice water resources conservation measures such as reusing water for non-potable uses such as watering lawns and gardens. Stakeholders are also encouraged to follow uMngeni-uThukela Water on various social media platforms for water conservation tips. Lastly, water users are advised 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 December 2023.
