Beneath the streets: Costa del Sol councils face questions over hidden waterways

A road closure in Torremolinos has raised questions about underground streams and drainage channels beneath Costa del Sol streets.

Emergency works begin on Monday, November 16 on Calle Decano José Gómez Rando, where the section between Calle Puerto Real and Calle Adelfas will close for an estimated three months. Aguas de Torremolinos are going to repair the covered channel carrying the Arroyo Pinillo, after inspections found material had been lost beneath the road. The council says this could cause localised subsidence during heavy rain. Residents will will still be able to get garage access, while traffic is diverted via Calle Saltillo.

Roadworks raise questions

The issue is not simply a roadworks inconvenience as many towns have streams channelled underground as urban areas expanded, leaving watercourses beneath roads, buildings and public spaces. Their job is to carry rainwater towards the sea, but structural damage, erosion or blockages can affect drainage and the ground above.

Torremolinos has had with problems with the same stream before. In 2020, repairs followed a sinkhole along the Arroyo Pinillo’s covered channel, with plans to replace a 300-metre section. The latest work raises questions about other sections and how regularly they are checked.

Unseen flood protection

The wider flood risk is well documented. The Junta de Andalucia’s urban flood-prevention plan identified 1,099 flood-risk points across 428 Andalucian towns, with Malaga, Granada and Almeria among the provinces most affected. The assessment dates from the late 1990s, not a current infrastructure inspection.

Malaga city illustrates the scale of maintenance involved. In October 2025, municipal water company Emasa said its preventive programme covered 2,600 kilometres of conduits, 40 kilometres of streams and covered watercourses, and almost 60,000 street drains.

For residents, the question is whether their council has an up-to-date record of covered streams, inspection schedules and repair priorities. EWN has previously reported water-related disruption in Las Lagunas and Fuengirola, although that incident involved a burst supply pipe, not so much an underground stream.

The Torremolinos closure is a reminder that essential infrastructure is out of sight, but not quite out of mind.