In the heart of the Souss-Massa nature reserve, where gazelles, ostriches and other migratory birds live side by side, stands the Chtouka-Aït Baha desalination mega-station. To get there, you’ll have to drive some 55 kilometers south of Agadir on the Nationale 1, passing through the communes of Aït Melloul, Sidi Bibi, Touzaikou and Aghroud.
Once in this small fishing village, take the road down to the coast to reach Douira beach, in the rural commune of Inchaden. It is here that this project, which has become crucial for the region’s drinking water supply and agricultural irrigation, has been built on about 20 hectares.
Double function
Less than two years after work began in 2020, in January 2022, the Regional Office for the Agricultural Enhancement of Souss – Massa (ORMVA-SM, Office régional de mise en valeur agricole de Souss-Massa) announced the commissioning of the first part of the project with the delivery of the first volumes of desalinated water, destined to supply drinking water to Greater Agadir. The second part, dedicated to agricultural irrigation of the Chtouka plain, began running in June 2022.
« The plant currently produces 275,000 m3 per day: 125,000 m3 for irrigation and 150,000 m3 for drinking water »
To get this plant out of the ground, 4.41 billion dirhams had to be spent, including 2.35 MMDH for the irrigation infrastructure and 2.06 MMDH for the drinking water infrastructure. « The plant currently produces 275,000m3 per day: 125,000m3 for irrigation and 150,000m3 for drinking water. Only the initial capacity is currently operational. But there is also a long-term capacity of 400,000m3/day already planned. It will be divided equally between irrigation and drinking water« , explains Ayoub Ramdi, State rural engineer, in charge of the desalination plant’s construction and operation at ORMVA-SM.
The fruit of a public-private partnership, the plant currently irrigates more than 10,000 hectares of crops on the Chtouka-Aït Baha plain with desalinated water, spread over almost 1,500 farms.
« The climate of Agadir and the region is arid to semi-arid. Added to this are the effects of climate change and drought on the region. This is why the station clearly plays a crucial role in preserving agricultural activity. In a way, it makes it possible to ignore all these factors, and thus optimize the conditions necessary for agriculture« , explains Ayoub Ramdi.
The ambition is to substitute desalinated water for groundwater withdrawals, which are currently virtually dry. « The main objective is to preserve the Chtouka water table, which has reached an annual deficit of 90 million m3 on average. This critical stage is alarming. The aim is also, of course, to preserve the region’s agricultural activity, which is facing water stress« , stresses Ayoub Ramdi.
Crucial for agriculture
Without this station, there would be no more fruit and vegetable crops. For example, you wouldn’t find tomatoes on the market, even at 50 or 100 dirhams a kilo », warns Lahcen Jabi, head of the agricultural sectors division at the Souss-Massa Regional Department of Agriculture
« Today, the dams are practically dry and there’s no rain to replenish the water tables. Without this station, there would be no more fruit and vegetable crops. For example, you wouldn’t find tomatoes on the market, even at 50 or 100 dirhams a kilo« , warns Lahcen Jabi, head of the agricultural sectors division at the Souss-Massa Regional Department of Agriculture.
This is all the more urgent given that agriculture is the Souss-Massa region’s main economic driver, along with tourism and fishing. According to the Haut-commissariat au plan (HCP), the agriculture, forestry and fishing sector is the region’s second-largest provider of jobs, with almost 5 out of 10 (49.3%) of the rural working population employed in this sector.
Souss-Massa is Morocco’s leading region in terms of early fruit and citrus cultivation, with a contribution of almost 9% to GDP. « Here, we have between 25,000 and 29,000 hectares of crops. What sets us apart here are early crops, i.e. crops grown outside their usual seasons. For this, we use greenhouses to artificially ensure the climatic conditions necessary for their production« , explains Lahcen Jabi.
« For example, we are the only region that produces tomatoes between October and May. In other areas, low temperatures don’t allow production during this period. As far as early fruit exports are concerned, the region accounts for 95% of volumes. For tomatoes, it accounts for almost all exports, and 65% for citrus. Unlike tomatoes and other crops, citrus is not irrigated with water from the plant« , he continues.
According to the Ministry of Agriculture, without the plant, there would be an annual loss of 9 billion dirhams in added value and 3 billion in capital. The project would also safeguard over a million jobs a year.
75% of the region’s drinking water
The National Office for Electricity and Drinking Water (ONEE, Office national de l’électricité et de l’eau potable) is equally satisfied with the desalination plant. « Before the plant was built, Greater Agadir was supplied with drinking water from so-called conventional water sources, i.e. surface water. This water came mainly from the Abdelmoumen and Moulay Abdellah dams and the water table« , explains Abdeslam Joulid, Regional Director of the Office. But with the succession of years of drought and the growing demand for drinking water in the city and its region, the supply of conventional water has become insufficient.
« Today, the plant meets 75% of Greater Agadir’s drinking water requirements », says a ONEE official
« The plant now meets 75% of Greater Agadir’s drinking water requirements« , says the official. He also explains that the project was designed to supply other neighboring municipalities whose water resources are no longer sufficient.
« There are 44 kilometers of pipelines from this station which are intended to serve localities suffering from water shortages and which, until recently, were supplied exclusively from groundwater. The groundwater was no longer able to supply these localities adequately due to overexploitation and drought« , emphasizes ONEE’s regional manager.
The commissioning of the project has made it possible to supply the communes of Lekliâa, in the province of Inezgane-Aït Melloul, and Sidi Bibi, in the province of Chtouka-Aït Baha. « We are in the process of building other connections to supply the axis to Biougra, via Aït Amira. Work is also underway on the route to Temsia, to supply this commune as well as Oulad Dahhou and Drarga. In the future, we plan to reach Oulad Taïma, in the province of Taroudant« , he adds. Abdeslam Joulid also assures us that the water produced by the plant meets all the required health standards.
Two pipelines in the sea
To understand the desalinated water production process, we need to dive back into the sea. It all starts at the catchment basin, connected to two large water pipes, each 1.1 kilometers long and 3 meters in diameter. « At sea level, there’s a concrete intake structure that looks a bit like a kitchen siphon. This structure allows water to be admitted by gravity, given the difference in levels. You have to imagine that the catchment basin is at a level of minus 6 meters NGM (Morocco’s general level in relation to sea level)« , explains engineer Ayoub Ramdi.
Once admitted to the basin, the water undergoes pre-treatment. « At the intake dam, there’s a bar screen with a mesh size of 15 to 20 centimetres, which eliminates any elements larger than this. The water then passes vertical bar screens with a smaller mesh of 30 mm (one thousandth of a millimeter). It then lands in self-cleaning rotary drum filters, with a mesh size of 3 mm », continues our contact.
The aim of this progressive filtration is to avoid « sudden clogging« . The water then reaches a high-pressure pumping station, where it is lifted and conveyed to the desalination unit for further treatment.
The production of drinking water is separated from that of irrigation. « The aim is to ensure that one does not impact the other in the event of a breakdown, for example. However, there are interconnections between the two to meet increased demand for drinking water, for example, at the time of Eid El Kebir. In this way, we can switch from producing water for irrigation to drinking water, as this becomes a priority« , stresses the engineer.
Reverse osmosis – the technology used to desalinate seawater – separates fresh water from salt water. Once this operation has been completed, some brine water remains, which is discharged back into the sea: « In the discharge basins, we have installed a turbine that recovers part of the energy injected into the plant. The aim is to reduce the plant’s energy consumption and provide 13% of the total power required ». This is all the more necessary as reverse osmosis technology consumes a lot of energy. According to Ayoub Ramdi, it takes almost 3 Kwh to produce a single cubic meter.
Ultrafiltration
After this stage, the water undergoes microfiltration to remove suspended matter, mainly sand, silt and clay, with a mesh size of 3 mm to 200 micrometers. Next comes ultrafiltration. « Here, we no longer speak of meshes, but of pores whose size varies between 0.1 and 0.01 micrometers. This stage eliminates bacteria and is carried out on two lines for irrigation and two others for drinking water« , continues the engineer.
Microfiltration and ultrafiltration are designed to improve raw water quality, prior to mineralization. This stage is carried out using calcite, a naturally occurring mineral rich in bicarbonate and calcium. The operation takes place in cubic tanks.
Water is deposited in the cubes, passing through a bed of calcite and rising to the surface fully mineralized. Irrigation water is then stored in a 43,500 m3 tank, while drinking water is stored in a 35,000 m3 reservoir. The final stage in the treatment process is the disinfection of the drinking water to make it fit for drinking.
In addition to its dual use for irrigation and drinking water, the Chtouka-Aït Baha desalination plant also acts as a shield against marine intrusion and soil salinization. An irreversible phenomenon that could have rendered the water table totally useless.
Drinking water: douars not connected
On the outskirts of Agadir, 202 douars are still not connected to the public drinking water distribution network managed by RAMSA. To remedy this situation, a special team from the wilaya is responsible for visiting these localities, which are part of the Agadir Ida Ou Tanane prefecture, on a daily basis.
« This operation is part of the Grouped drinking water supply program for rural populations (PAGER, Programme d’approvisionnement groupé en eau potable des populations rurales) and concerns the two districts of Agadir-Atlantique and Agadir-Banlieue« , explains Abdelouahed Aouk, technician at the delegation of Entraide nationale at the wilaya of Agadir.
« In the Agadir-Banlieue circle, 47 douars are not connected to the drinking water distribution network. Every day, two tanker trucks distribute drinking water to them, which is stored either in plastic tanks made available to them or in wells. Distribution is based on the needs identified by the local authorities for each douar, » he adds.
According to the latest figures communicated by the Minister of Equipment and Water, Nizar Baraka, connection to the drinking water network will not exceed 65% by the end of 2021, while connection to the liquid sanitation network in rural areas will be barely 10%[/frame]
Written by Ghita Ismaili. Edited in English by S.E.
