Morocco's water, after the drought

The catalogue's Dams of Morocco dataset lists 135 dams commissioned up to 2005, with 16.1 billion m³ of capacity. Each of the 103 dams with a known capacity is a column, as tall as what it can hold. Two giants account for 40%: Al Wahda on the Ouergha (3.73 billion m³) and Al Massira on the Oum Er-Rbia (2.76).

Year after year, from 2013 to 2024, the water of the Al Massira reservoir as seen by Landsat satellites (JRC). Measured on these images, its surface falls from 131 km² to 16 km². The country's second-largest dam watched its reservoir melt away over ten years of poor rainfall.

The same reservoir five years apart, photographed by Sentinel-2. On 14 June 2022 the country's dams were 31.8% full; Al Massira was at 6.3% of its capacity, according to the General Directorate of Hydraulics as cited by Copernicus. The bleached banks trace the former shoreline.

At the start of each hydrological year, the national filling rate tells the story of the drought: 36.6% in October 2021, 25.5% in 2022, 25% in 2023. It edges up in 2024 and 2025, then doubles at once: 65.51% on 1 October 2026, against 32.68% a year earlier. River basins draw the map of this water.

Month by month, from October 2025 to April 2026, rainfall estimated from satellites and stations (CHIRPS). The darker the blue, the more it rained. On 22 June 2026, dams were 74.1% full, against 38.5% a year earlier; the Tensift, Loukkos, Sebou and Bouregreg basins were above 86%.

On 1 October 2026, each column is a basin, set on its largest dam: its height shows the filling rate. The north and the Atlantic side are three-quarters full; the south is still struggling, the Draa-Oued Noun at 34%. The Oum Er-Rbia, nearly dry in 2025, has quintupled — only the Guir-Ziz-Ghris fell over the year.

Since 28 August 2023, a 3.2 m steel pipe has carried water from the Sebou to the Sidi Mohammed Ben Abdellah dam, which supplies Rabat and Casablanca: 67 km, up to 15 m³ per second, 6 billion dirhams. By 5 November 2024, 484 million m³ had been transferred.

In March 2026, 17 plants desalinated 350 million m³ a year; the target is 1.7 billion by 2030. At Chtouka-Aït Baha, near Agadir, the plant produces 275,000 m³ a day, 125,000 of which irrigate 15,000 hectares. In Casablanca, the first phase (548,000 m³ a day) is expected in February 2027.

On 9 August 2026, the stony shore of Al Massira, a pontoon on the water. On 1 October, the Oum Er-Rbia basin was 57.85% full, against 10.03% a year earlier. The reservoirs refilled in one winter; groundwater will need more, and desalination is moving ahead so as not to rely on the sky alone.