La Viñuela reservoir is at 17 per cent of its capacity / e. cabezas

Father and daughter engineering team come up with Axarquía drought solution

Despite the rain the level of water in La Viñuela reservoir has only increased by four cubic hectometres in recent weeks, equivalent to one month’s consumption of water

Eugenio Cabezas

Although the rains in March and April have brought significant relief to the Malaga countryside in general, in the Axarquía the situation is only marginally better. Despite the rainfall, the level of water in La Viñuela reservoir has only increased by four cubic hectometres in recent weeks, equivalent to one month’s consumption of water.

The reservoir is at just 17 per cent of its capacity, with 28 cubic hectometres stored. It supplies more than 200,000 inhabitants of 14 municipalities in the eastern part of Malaga province, as well as irrigating almost two thirds of the 13,000 hectares of crops, mainly mangoes and avocados.

Subtropical fruit growers face a bleak summer and have already seen their water quotas halved from 3,000 to 1,500 cubic metres per hectare in the space of a year. Twelve months ago La Viñuela also stored twice as much water. However, growers complain that for an avocado farm to survive, it needs at least 4,000 cubic metres per hectare per year.

A succession of proposals

Against this backdrop, in recent months there has been a succession of proposals to seek alternative resources of water, many of which have either considered using regenerated water from local waste water treatment plants or desalination plants.

The University of Malaga and the company Abengoa came up with one project involving two large desalination plants at the request Vélez-Málaga; Adolfo Aragüez and his daughter Inés, who are responsible for the company I+Db Acoustic came up with another..

It is a "very innovative" proposal compared to the two previous ones, with the idea that "the solution can be implemented quickly, economically and be fully adapted to the needs of each user", explained Adolfo Aragüez. "The proposals are very ambitious, would require costly investments and have lengthy processing times requiring tenders that would take several years before they could start to be built," explained the 63-year-old founder of the firm.

However, the project, designed together with his 30-year-old daughter, is a "more scalable and evenly distributed system, designed above all and exclusively for agricultural use in emergency situations,” says Aragüez. "It is totally innovative, and can bring about a great change in Mediterranean agriculture and help to create local jobs associated with the manufacture, installation and maintenance of the equipment involved, using national technologies," he points out.

Added value to local produce

The proposal is based on water being extracted from coastal areas through boreholes around the mouths of the main rivers, such as the streams in Rincón de la Victoria and the Vélez, Algarrobo and Torrox rivers. The water would be pumped and distributed to agricultural areas or, where appropriate, mixed in to the tanks that would treat the recycled water from the treatment plants.

The water would undergo a demineralisation process on each farm to ensure that the irrigation process was totally free of pollutants and heavy metals, "thus giving added value to the Axarquía’s produce," Aragüez emphasises.

Each plot would have its own individual desalination system, "which would be adapted to their needs and could be powered by mains electricity or, where appropriate, with the support of a conventional or floating photovoltaic system in each grower’s own reservoir, thereby reducing evaporation," Aragüez explains.

The project would also have mini-hydraulic turbines to generate energy for the pumping system and in addition, the existing pumping system in the boreholes could be used to channel surface water from the area’s rivers and streams to La Viñuela reservoir when it rains. Aragüez adds that building surface water dams at the end of the rivers could also increase the amount of water captured and redirected to the reservoir.

Minimal environmental impact

According to Inés and her father, the main advantage of their proposal is that it is "a scalable system that is quick and easy to implement". They argue that the “public investments needed are only a small fraction of those proposed in other projects, since a large part of the necessary infrastructures already exist, which means that they can be implemented very quickly.”

Each farmer would finance their own desalination system, which can be shared, rented or sold and even in times of high water availability, these desalination plants could be rented to other areas where they are needed. However, in Aragüez's opinion, "incentives and subsidies should be articulated to facilitate these investments". Moreover, in the event of a disaster that damaged drinking water systems, "these desalination plants could be vital for supplying drinking water to the population,” he adds.

For the two Velez engineers, it is logical that "pumped seawater is infinitely available, there will never be a shortage of this flow” and they argue that “its impact on the marine environment will be minimal.”

Inés and Adolfo Aragúez in Vélez-Málaga / sur