Desalinating well and borehole water in Morocco: a guide for farmers, livestock breeders and hotels

The rains of winter 2025-2026 gave the country some breathing room: on 13 November 2026, dams were 66.2% full, against 30.8% a year earlier. But the improvement is uneven. The Souss-Massa and Drâa-Oued Noun basins were only 46% and 39% full in early November, and many farms, livestock operations and hotels still depend on a well or borehole whose water has become too salty.

This is one of the requests we receive most often. This year we were consulted by a poultry farm whose well water exceeded 1,200 mg/l of chlorides, a 2.7-hectare fig orchard fed by a 120 m borehole, a 4-hectare farm near Agadir looking for a solar desalination plant, a seaside hotel project near Tan-Tan, and a village in the Zagora region that wants to make very saline water drinkable.

1. Start with a complete water analysis

No serious sizing is possible without an analysis. The parameters that matter for reverse osmosis are:

• Conductivity and TDS (total dissolved solids): they set the operating pressure and the membrane choice;
• Chlorides, sodium, sulphates: these are what burn crops and affect animals;
• Hardness (calcium, magnesium), bicarbonates, silica, barium, strontium: they define the scaling risk and therefore the achievable recovery rate;
• Iron and manganese: common in boreholes, they foul membranes if not removed upstream;
• Nitrates and bacteriology: essential if the water is for drinking.

For irrigation, the FAO guidelines remain the reference: below about 0.7 dS/m (700 µS/cm) water has no restriction on use, between 0.7 and 3 dS/m restrictions are slight to moderate depending on the crop, and above 3 dS/m they become severe. For livestock watering, specialists generally recommend staying below 1,000 mg/l of dissolved solids for poultry.

2. Choose the right technology

For brackish borehole water (usually 1 to 10 g/l of salts), low-pressure reverse osmosis is the standard solution. A typical installation includes:

• pretreatment: sand or multimedia filter, iron removal if needed, 5 µm cartridge filters and antiscalant dosing;
• pressure vessels and membranes, sized for the target flow and recovery rate (often 60 to 80% on brackish water, depending on hardness and silica);
• remineralisation, or blending with raw water for irrigation, so the water is not too aggressive;
• treated-water storage, so you can produce during sunshine hours and irrigate when needed.

For very hard or silica-rich water, high-recovery processes (closed-circuit RO, two-stage designs) reduce the volume of brine.

3. Pair reverse osmosis with solar power

The high-pressure pump accounts for most of the electricity use. On a farm, a solar PV array sized for the borehole pump and the RO unit lets you produce without an electricity bill during sunshine hours. The treated-water basin or tank then acts as the "battery". This configuration suits projects of a few m³/h in rural areas well.

4. Brine: a point not to overlook

Reverse osmosis rejects part of the water as salty brine. Its handling must be planned from the start: lined evaporation pond or duly authorised discharge. Under Law 36-15 on water, any discharge that could harm the public water domain needs an authorisation from the river basin agency (article 98), and an unauthorised discharge carries a fine of MAD 10,000 to 500,000 (article 147). Dumping brine into a wadi or back into the aquifer is therefore not an option.

5. Borehole obligations

Law 36-15, as amended by Law 05-23, also regulates the resource itself:

• abstracting groundwater from a well or borehole requires an authorisation (article 28);
• the authorisation lasts at most 10 years and requires a water meter (article 31);
• only licensed drillers may carry out the work (article 114), and an illegal borehole carries a fine of MAD 10,000 to 100,000 (article 149).

In several regions the authorities now monitor abstraction and seal unauthorised boreholes. A compliant file is therefore the first step of any desalination project.

6. A national movement

The government itself is betting on local desalination: a programme of 244 mobile units desalinating seawater and brackish groundwater has been launched for rural areas; 124 of them had been delivered by the end of March 2026. For a farm, a livestock operation or a tourist establishment, a custom-sized unit follows the same logic: producing water of constant quality on site, whatever the year's rainfall.

Sources

• Law no. 36-15 on water (loi 36-15), consolidated text (SGG, 30/07/2025) — sgg.gov.ma
• Dam fill rates on 13/11/2026 — TelQuel
• Programme of 244 mobile desalination units — Hespress FR
• FAO, Water quality for agriculture (Ayers & Westcot, Irrigation and Drainage Paper 29)

Information article, up to date on 14 November 2026. It does not replace the official texts or the advice of your river basin agency (ABH) or network operator.