Groundwater Reservoirs Have Benefited Less from Rainfall than Dams

While Moroccan dams show a 76.2% filling rate, the level of underground water tells a different story.

An analysis of satellite data over the past decade reveals a disparate and timid rebound.

This season has allowed for the replenishment of part of Morocco's hydraulic reserves.

Like dams, whose filling rate currently exceeds 76.2%, underground water levels should also experience a significant increase.

However, does this rebound actually occur in the aquifers?

In the absence of sufficient precipitation over the past three years, these aquifers have faced strong pressure to compensate for the lack of water in dams and the suspension of collective irrigation in major agricultural areas.

Using satellite data, we track the recent evolution of the main regions to quantify the impact of this season on these precious resources.

Although this is an estimate, it allows for a vision close to reality, with field measurements remaining the most reliable data.

In reality, these satellites do not 'see' water directly.

The values obtained reflect the variations in the terrestrial gravitational field.

Water being a significant mass, its movements modify the local gravity.

Thus, a value of +30 cm does not mean there are 30 cm of water at this location, but rather that there is an additional 30 cm of water equivalent to the reference period of the satellite.

Conversely, a negative value indicates a water deficit relative to this same reference.

To obtain a global view of the evolution of water resources in Morocco, particularly underground, we present here a regional analysis covering the past decade, with the period 2004-2009 serving as a reference.

In northern Morocco, the Loukkos region, affected by recent flooding, has seen its levels exceed the reference period threshold.

However, since 2019, satellite readings have indicated a negative anomaly characteristic of recent drought years, despite periodic oscillations remaining consistently below the average.

The maximum was recorded in February 2026 with +8.9 cm above the reference average, while the minimum reached -20 cm in September 2022.

In contrast, the nearby Gharb basin has experienced a much more timid evolution.

The maximum positive evolution recorded does not exceed +1.39 cm relative to the reference period.

Like the Loukkos region, it was from December 2019, corresponding to the beginning of the last drought, that a persistent negative anomaly began to emerge, without returning above the reference average until the beginning of 2026.

The most marked trough was observed in September 2022, at -18 cm.

In the center of the country, the post-2019 collapse was particularly brutal, illustrating the severity of the drought that hit these vital agricultural basins.

Although 2026 marks a turning point, the accumulated deficit remains significant.

South of Casablanca, covering the regions between Settat, Berrechid, and El Jadida, negative anomalies have continued since 2015, although the winter rains of 2026 allowed for a significant rise, bringing the level from -14 cm to -9 cm.

Although still negative, this progression exceeds the levels recorded in 2020 for the first time.

Between 2009 and 2013, resources were above the reference average, before beginning a continuous regression.

August 2015 corresponds to the last period to have recorded a positive anomaly.

Similarly, the Fès-Meknès region experienced a significant rise at the beginning of 2026, with levels rising from -12 cm to -6 cm, a 50% improvement; they remain, however, below the reference average.

The same is true for the region of Marrakech-Safi, where levels have risen from -10 cm to -5 cm, a 50% improvement, but still below the reference average.

In the eastern part of the country, the Taounate region has experienced a significant rise, with levels rising from -15 cm to -8 cm, a 46.7% improvement, but still below the reference average.

The same is true for the region of Oujda-Angad, where levels have risen from -12 cm to -6 cm, a 50% improvement, but still below the reference average.

In the western part of the country, the Laâyoune-Sakia El Hamra region has experienced a significant rise, with levels rising from -18 cm to -12 cm, a 33.3% improvement, but still below the reference average.

The same is true for the region of Dakhla-Oued Ed-Dahab, where levels have risen from -15 cm to -10 cm, a 33.3% improvement, but still below the reference average.

In conclusion, while the recent rains have allowed for a significant rise in some regions, the accumulated deficit remains significant, and the situation remains critical.

It is essential to continue monitoring the evolution of water resources in Morocco, particularly underground, to ensure the sustainability of these precious resources.