Mare-aux-Vacoas Reservoir at Risk of Hitting 20% Capacity by November

Mauritius's primary water reservoir, Mare-aux-Vacoas, is under serious strain, with the Central Water Authority (CWA) warning that water levels could fall below the critical 20% threshold before the end of November if conditions do not improve. Located in the Plaines Wilhems district in the centre of the island, Mare-aux-Vacoas is the largest reservoir in Mauritius and a cornerstone of the country's drinking water supply. When its levels drop significantly, the consequences are felt island-wide — from household water cuts to pressure on agriculture and industry. **Why 20% matters** Water authorities treat 20% capacity as a red line. Below that level, it becomes increasingly difficult to maintain reliable supply across the pipe network, and the risk of prolonged, scheduled water rationing — known locally as "coupures d'eau" — rises sharply. Pumping water at very low reservoir levels can also damage infrastructure and degrade water quality. The CWA, the state body responsible for water production and distribution in Mauritius, is actively managing withdrawals and distribution schedules to slow the rate of depletion. **What is causing the low levels?** The reservoir's stress reflects a broader pattern of below-average rainfall in the central highlands, which feed Mare-aux-Vacoas through a network of catchment streams and tunnels. Mauritius typically relies on the wet season — which runs from November through April — to replenish its reservoirs. However, the onset of meaningful rainfall has been delayed or insufficient in recent weeks. Climate variability, including drier dry seasons and less predictable rainfall patterns, has made reservoir management increasingly difficult for authorities in recent years. **What this means for residents** Households already experiencing intermittent water supply — particularly in areas that depend heavily on Mare-aux-Vacoas — could face more frequent or longer cuts if the situation does not improve. The CWA has been urging the public to use water sparingly and avoid wastage such as washing vehicles or watering gardens during peak demand periods. For businesses, hotels, and the agricultural sector, prolonged low reservoir levels can mean significant operational disruption and added costs from sourcing alternative water supplies. The situation will be closely watched through November, with rainfall in the coming weeks likely to determine whether emergency rationing measures are required heading into the holiday season — one of the busiest periods for tourism and domestic water demand. Source: Le Défi Media