Morocco’s dam reserves fell by roughly 1.46 billion cubic metres between mid-May and early September, with the national filling rate slipping from 76 percent to 67.5 percent, according to the Water Research and Planning Directorate’s daily bulletin cited by Le360 news outlet. Total reserves stood at 11,493.38 million cubic metres on September 1, down from 12,953 million on May 18, as monthly withdrawals for irrigation, drinking water and evaporation topped 400 million cubic metres throughout the summer.
Every river basin lost ground over the summer, though unevenly. The Moulouya basin recorded the steepest decline, from 73.7 percent to 56.46 percent, while the Tensift, Loukkos and Bouregreg basins each shed 11 to 15 points. The Sebou, the country’s largest reserve, held up better, slipping from 88.4 percent to 80.5 percent despite the largest volume drawdown of any basin, at nearly 425 million cubic metres. The Oum Errbia limited its decline to just over 6 points, while the Souss-Massa and Draâ-Oued Noun basins posted more moderate losses.
Among the twenty largest dams, performance varied widely. Al Wahda and Al Massira, the country’s two largest reservoirs, showed remarkable stability, losing under 2 and under 4 points respectively, while Oued El Makhazine, Idriss Ier and El Kansera each lost more than 18 points. The Mohammed V dam in the lower Moulouya saw the sharpest fall of all major dams, dropping from 91 percent in mid-May to just 25.97 percent by September, as it absorbed most of its basin’s irrigation releases. Agdez, on the Draâ, was the rare dam to gain ground, rising from 35 percent to 38.69 percent.
Despite this summer erosion, the situation remains far more favorable than a year ago: the national filling rate stood at just 33.79 percent on September 1, 2025, meaning current reserves are exactly double last year’s level, a cushion expected to provide an unprecedented safety margin heading into autumn and the next agricultural campaign.
