Pressure on western Costa del Sol's main water supply reservoir eases by almost a quarter

The Costa del Sol's dependence on the water resources stored in La Concepción reservoir, between Marbella and Istán, is decreasing. At the end of last year, according to sources from the public water management company Acosol, the use of this reservoir's water supply was reduced by 23%. In this case, we are talking about year-end data, although it is common for the final reckonings of water supplies to be carried out according to the hydrological year (from 1 October).

There are several key issues here. Firstly, Marbella's desalination plant was used to a greater extent. The first phase of the project to recover its nominal capacity (the first leap in supply was from six to 12 million cubic metres per year) was completed in the autumn. The second phase has just been completed and has raised this potential to 20 million cubic metres, so it is to be expected that the end of the current year will mark an even less pronounced dependence on the reservoir.

The second key factor is the increased use of resources such as the Guadalmansa and Estepona wells, reclaimed water and other sources of supply in the hands of the municipalities belonging to the Mancomunidad de Municipios de la Costa del Sol (the alliance between several towns along the western Costa del Sol for managing shared resources such as water).

The third element, no less crucial, was the various restrictive scenarios set out by the Junta de Andalucía's drought management committee. Fortunately, the Costa del Sol was the first place in Malaga province to abandon all alerts and shortage thresholds to return to a situation of normality.

In 2023, Acosol used 47.6 million cubic metres of water from La Concepción. In 2024 the use of this resource was reduced to 36.5 million cubic metres.

As for the Marbella desalination plant, last year 9.7 million cubic metres were used, compared to eight the previous year. The management of the aforementioned modernisation work allowed for the gradual installation of new lines and frames.

Overall, the total amount of drinking water supplied by the mains network (including the reservoir, desalination plant and groundwater resources) was 61 million cubic metres in 2023. The figure was reduced to 52 million cubic metres in 2024, an overall decrease of 14.5%.

The forecast for the summer is encouraging across the entire Costa del Sol area. In fact, the reservoir was storing 54 million cubic metres at the start of the weekend, which represents almost 95% of its full capacity. The reservoir would have held much more had excess not had to be released during the big rain storms in March. Adding this to the discharge required through the upper spillway in May, the reservoir could have been filled one and a half times as much. The total of water released was around 30 million cubic metres.

The Costa del Sol's water consumption needs are estimated to be around 100 million cubic metres per year, including all operators (both high and low) and reclaimed water. In this regard, Acosol is planning to increase use of the latter given that, despite producing 47 million cubic metres per year, only between seven and ten of those 47 are sold, depending on the year. The medium-term goal is to reach 30 million cubic metres, for which work is underway to process permits for the irrigation of public gardens in the first instance, followed by private gardens.