💧 Morocco’s Rivers & Dams
Watercourses, Reservoirs & Hydraulic Heritage
From the mighty Oum Er-Rbia to seasonal oueds, and the monumental dams that secure water for millions
Oum Er-Rbia
Originating in the Middle Atlas, flowing 555 km to the Atlantic near Azemmour. It powers multiple large dams (Bin El Ouidane, Al Massira) and irrigates the fertile plains of Tadla and Doukkala.
Sebou River
Length: 458 km. Flows from the Middle Atlas to the Atlantic near Kenitra. Its basin produces over 40% of Morocco's agricultural output. Major dams: Idriss I, Garde de Sebou, and more.
Draa River
Length: approx. 1,100 km (longest in Morocco, but seasonal). Originates in the High Atlas, flows south to the Atlantic. Dams: Mansour Eddahbi (near Ouarzazate) creates a vast reservoir.
Loukkos · Laou · Martil
The Loukkos (180 km) flows near Larache into the Atlantic, vital for irrigation. Laou and Martil are short but scenic Mediterranean rivers in the Rif.
Ourika · Tensift · Ziz · Rheris
Ourika is a famous valley near Marrakech; Tensift is the river basin for the Marrakech plain. Ziz and Rheris create palm oases in the pre-Saharan zone (Errachidia, Tafilalet).
Bou Regreg · Ksob · Souss
Bou Regreg (240 km) separates Rabat and Salé. Souss River (190 km) flows through Agadir region, essential for argan and agriculture. Ksob drains the Essaouira area.
🔹 Morocco has over 140 large dams with a total storage capacity exceeding 18 billion m³
Dams serve multiple purposes: irrigation (over 1.5 million hectares), drinking water supply, flood control, and hydroelectric power (about 15% of national electricity). Below are key dams and their associated rivers.
Bin El Ouidane
On Oum Er-Rbia river. One of Morocco's largest dams (capacity 1.38 billion m³). Supports irrigation in Tadla and hydroelectric production.
Al Massira
Also on Oum Er-Rbia, downstream. Capacity: 2.7 billion m³. Crucial for drinking water to Casablanca and irrigation of Doukkala plain.
Mansour Eddahbi
On the Draa River near Ouarzazate. Capacity 560 million m³. Regulates the Draa oasis and provides water for the southern region.
Idriss I & Garde de Sebou
Idriss I (capacity 1.2 billion m³) on Inaouen River (tributary of Sebou). Garde de Sebou (Wahda) is the largest dam in Morocco: 3.8 billion m³ on the Sebou river — a massive reservoir for irrigation and flood control.
Mohamed V · Hassan Addakhil
Mohamed V dam on Moulouya river (eastern Morocco) with 730 million m³ capacity. Hassan Addakhil dam on Ziz river near Errachidia, essential for Tafilalet oases.
Youssef Ibn Tachfine · Ait Aadel
Youssef Ibn Tachfine on Massa river (south of Agadir), Ait Aadel on Souss river, both key for southern agriculture and drinking water.
| River Name | Length (km) | Main Dams / Reservoirs | Region / Notes |
|---|---|---|---|
| Draa River | 1,100 km | Mansour Eddahbi | Longest river (intermittent), southern Morocco |
| Oum Er-Rbia | 555 km | Bin El Ouidane, Al Massira, Afourer, Ait Ouarda, Imfout, Daourat, Sidi Said | Central Morocco, Atlantic basin |
| Sebou River | 458 km | Al Wahda (Garde de Sebou) — largest in Morocco, Idriss I, Allal El Fassi (on tributary), El Kansera, Sidi Chahed | Northern Morocco, most fertile basin |
| Moulouya River | 520 km | Mohamed V, Mechraa Hammadi, Enjil | Eastern Morocco, longest in the east, flows to Mediterranean |
| Bou Regreg | 240 km | Sidi Mohamed Ben Abdellah | Separates Rabat & Salé, Atlantic coast |
| Loukkos River | 180 km | Oued El Makhazine, 9 April 1947 dam | North-west, irrigates Larache region |
| Souss River | 190 km | Ait Aadel, Mokhtar Soussi, Abdelmoumen | Agadir area, vital for argan and agriculture |
| Tensift River | 270 km | Lalla Takerkoust, Cavagnac, Moulay Youssef | Marrakech region, Haouz plain |
| Ziz River | 282 km | Hassan Addakhil | Tafilalet oases, pre-Saharan |
| Rheris River | ~250 km | — (several small retention structures) | Errachidia region, seasonal |
| Ourika River | ~60 km | — (tributary of Tensift) | High Atlas, popular valley near Marrakech |
| Massa River | ~120 km | Youssef Ibn Tachfine | South of Agadir, Souss-Massa National Park |
| Ksob River | ~100 km | Zima, L'Abbassia | Essaouira region, Atlantic |
| Laou River | ~70 km | — (small irrigation dams) | Rif Mountains, Mediterranean basin |
| Martil River | ~60 km | — | Near Tetouan, Mediterranean coast |
| Inaouen River | ~180 km | Idriss I (tributary of Sebou) | Middle Atlas, feeds Sebou basin |
| Beht River | ~150 km | — (tributary of Sebou) | Central Morocco, important for irrigation |
| Oued Mellah | ~65 km | Oued Mellah dam (small) | Near Mohammedia, Atlantic |
| Oued N'fis | ~130 km | — | Tributary of Tensift, High Atlas |
| Oued Grou | ~90 km | — | Tributary of Bou Regreg |
| Oued Tizguite | ~70 km | — | Middle Atlas, tributary of Sebou |
Agricultural Pillar
Dams irrigate over 1.5 million hectares of farmland, supporting citrus, olives, cereals, and vegetable production — essential for food security and exports.
Renewable Energy
Hydroelectric plants at dams like Bin El Ouidane, Al Wahda, and Mansour Eddahbi contribute to Morocco's clean energy mix (over 1,700 MW installed capacity).
Urban Supply
Major cities like Casablanca, Rabat, Marrakech, and Agadir depend on dam reservoirs for their drinking water, especially during dry years.