The island nation of Mauritius is grappling with water supply challenges, with the Mare-aux-Vacoas reservoir currently at 36.6% capacity. According to recent data, the reservoir's water level has dropped significantly, with an average daily treatment of 71,000 cubic meters at La Marie, down from the normal 110,000 cubic meters. This decline has raised concerns about the country's water management and the impact of changing rainfall patterns.
The Minister of Energy and Public Services, Patrick Assirvaden, has suggested that changes in rainfall distribution may be contributing to the water supply issues. However, data from the national weather station indicates that the Plateau central region received significant rainfall in July, August, and September, with 211 mm, 210 mm, and 116 mm of rainfall, respectively. These figures are higher than the national average for the same period.
A review of historical rainfall data from 1950 to 2025 reveals that Mauritius has experienced a decline in rainfall in recent years. The national average rainfall for 2021-2025 was approximately 1,030 mm per year, which is 6% lower than the long-term average of 1,096 mm. Furthermore, the 2025 rainfall value was 893.5 mm, which is 18% below the historical average.
The weather station's data also shows that the summer of 2025-2026 was particularly dry, with cumulative rainfall of 889 mm, which is 66% of the long-term average. The deficit worsened from January, with 136 mm of rainfall, or 48% of normal, followed by 105 mm in February, or 33%, and 160 mm in March, or 54%. March 2026 was also classified as the fifth hottest month since 1960.
Despite the rainfall in the Plateau central region, the Mare-aux-Vacoas reservoir remains at a significantly lower capacity compared to other reservoirs on the island. The six other reservoirs have collective levels of around 72%, while Mare-aux-Vacoas is below 40%. This disparity suggests that factors other than rainfall may be contributing to the water supply issues.
The available data do not provide a clear explanation for the water supply challenges in Mauritius. While changes in rainfall patterns may be a contributing factor, it is unclear whether this is the sole cause of the issue. Further analysis of rainfall and water supply data is needed to determine the underlying causes and develop effective solutions.
The water supply situation in Mauritius remains a pressing concern, with the Mare-aux-Vacoas reservoir at a critical level. The government and water management authorities must work together to address the issue and ensure a reliable water supply for the island nation. This will require a comprehensive analysis of rainfall patterns, water supply systems, and other factors contributing to the challenges.
Key points
- The Mare-aux-Vacoas reservoir is currently at 36.6% capacity, with a significant decline in water supply.
- Rainfall patterns in Mauritius have changed in recent years, with a decline in rainfall in the 2021-2025 period.
- The Plateau central region received significant rainfall in July, August, and September, but the Mare-aux-Vacoas reservoir remains at a low capacity.
