Malaga city now has 21 active wells as reservoir water alternative

For a long time, water management in Malaga largely overlooked groundwater, but after the severe drought, which the provincial committee has just declared over, this resource has regained importance.

It is a difficult resource to maintain because it requires perfectly functioning facilities (pumps, electricity, pipe cleaning, etc.). Furthermore, it is vulnerable to flash floods and storms and always carries the risk of overexploitation, which can lead to issues of quality.

Municipal water company Emasa has just awarded specialist company Talher a one-year contract for the maintenance of the city's 21 well facilities (plus three complementary installations). The amount is 345,847 euros, including taxes.

The water supply for the city of Malaga depends primarily on the Guadalhorce reservoir system (Conde, Guadalhorce and Guadalteba) and, to a lesser extent on flood control dams El Limonero and Casasola. The next most important resource is the water flowing into the Guadalhorce river from the Grande reservoir, which is used at the Aljaima weir when the flow rate allows. This is not a storage facility, so any water that cannot be used in the network is diverted over the weir and flows out to sea.

Around Aljaima (Cártama) there is a network of wells that have been used and restored for years. They have suffered numerous setbacks over time due to overflows and rain, but the effort to keep them active and in good condition is considerable. They all feed into the reservoir, which also receives water from the weir. From there, it goes to El Atabal for treatment.

Having a desalination plant is crucial, since wells sometimes present high concentrations of salt (conductivity) and other quality issues.

In recent months, five large wells in the Bajo Guadalhorce area have resumed operation - a very promising development given their estimated capacity of 800 litres per second (approximately half of Malaga city's water demand). However, authorities should not exploit this potential to its fullest extent and must exercise sufficient rationality to ensure the proper maintenance of the wells and facilities and avoid depleting the aquifer.

The restoration works in the Bajo Guadalhorce Valley have involved an investment of 16 million euros, primarily from the Andalusian regional government. The hydrogeology centre of Malaga University is in charge of both the preliminary studies and the monitoring of the wells at Puente del Rey and Perales.

The contract Talher has signed details the facilities that need maintenance. These include the eight pumps at the Aljaima weir (400 litres per second) and the wells in this area. The wells range in depth from ten to 29 metres and the pumps have capacities from 30 to 160 litres per second. The diameters of the boreholes range from 35 to 40 centimetres.

The deepest wells are in the Bajo Guadalhorce Valley (airport and Santa Teresa industrial park areas): some reach 60 metres and have pumps with a capacity of up to 110 litres per second. The booster pumps for this entire system exceed 300 litres per second. In the case of Perales 3, the borehole diameter exceeds 6.5 metres, and in Perales 1, it exceeds four.