Mare-aux-Vacoas Reservoir Drops to 36.6% — Down from 89.6% a Year Ago

Mauritius is facing a sharp deterioration in its water reserves, with the Mare-aux-Vacoas reservoir — the island's largest and most strategically important — now sitting at just 36.6% capacity. At the same point last year, the reservoir stood at 89.6%, making the year-on-year drop of more than 53 percentage points one of the most severe declines in recent memory. **What is Mare-aux-Vacoas?** Mare-aux-Vacoas is the biggest reservoir in Mauritius, located in the central highlands of the island in the Plaines Wilhelms district. It serves as a critical source of drinking water for a large portion of the population and is managed by the Central Water Authority (CWA), the government body responsible for water production and distribution across the island. The reservoir is fed primarily by rainfall in the central plateau region. Mauritius typically relies on the wet season — broadly from November to April — to replenish its reservoirs. When rainfall is below average or poorly distributed, storage levels can fall sharply. **Why is this significant?** A reservoir level of 36.6% is well below what authorities would consider comfortable heading into the drier winter months. Low reservoir levels can trigger water rationing — a scenario many Mauritians are familiar with, where pipe supply is cut to certain hours of the day in affected districts. The contrast with 2025 is particularly stark. Last year at this time, Mare-aux-Vacoas was nearly full, giving the CWA ample buffer for distribution. This year's figure leaves little room for manoeuvre if rainfall remains insufficient in the coming weeks. The situation at Mare-aux-Vacoas is also likely to reflect conditions across other reservoirs on the island, though the CWA monitors each catchment area independently. **What this means for residents** Households in areas supplied by Mare-aux-Vacoas — including parts of Curepipe, Quatre Bornes, Vacoas-Phoenix and surrounding districts — may face increased pressure on water supply if levels continue to fall. Businesses, hotels, and agricultural users who depend on CWA infrastructure could also be affected. Authorities have not yet announced emergency rationing measures, but the figures underline how quickly Mauritius's water security can shift from year to year, driven almost entirely by rainfall patterns that are increasingly unpredictable. Environmental groups and water policy analysts have long called for greater investment in water storage infrastructure, demand management, and rainwater harvesting to reduce the country's vulnerability to dry spells. Source: Le Defi Media