Reducing Flood Risk at the Gros Stream

Improvements to the riverbed and environmental restoration along a key stretch of the Palma metropolitan area

What does it consist of?

The Balearic Government is making improvements to a section of the Gros Stream, a major watercourse on the island of Mallorca. The plan focuses on fortifying riverbanks and widening the riverbed to tackle the risk of collapse and overflow, especially in areas bordering towns and farms.

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Data

PROJECT TITLE IN THE CALL
Bed improvement and bank upgrading of Torrent Gros, Manacor Highway–Vella de Sineu Highway. Municipality of Palma
LOCATION
Mallorca (Palma de Mallorca)
Entity submitting the PROJECT
Govern de les Illes Balears
Entity that executes the project
Conselleria de Medi Ambient i Territori
Project code
ITS2019-140
Total project amount
1.443.000 €
ITS granted amount
1.443.000 €
Executed amount
77.242 €
Call year
2019
Execution status
Started
Purpose
Environment
Budget execution
Executed: 5.35%
Last data request
09.04.2026

The project

Short spells of heavy rainfall, typical of the Mediterranean climate, make streams on the Balearic Islands a critical element for safety in the region. In particular, the Gros Stream, one of the largest on the island with a basin of more than 200 km², poses a potential flood risk as it runs through densely urbanised areas such as the municipality of Palma.

This plan seeks to adapt the section that runs between the Carretera de Manacor road and the old Carretera de Sineu road, in an area where the riverbed is highly eroded and lacks water, which increases risk in the event of torrential rain. At some points, the banks lack erosion control, increasing the likelihood of landslides and blockages.

The planned actions include the construction of a low water channel enclosed with gabion walls with electro-welded mesh, an efficient and sustainable technique for erosion control. Berms will also be created with leftover material from excavation, thus reducing the environmental impact of earthworks.

The intervention will also involve ecological restoration techniques, such as hydroseeding on the new riverbank terraces and the installation of perforated concrete slabs on the bed, which will support infiltration and plant stability, helping to naturalise the riverbed.

Although still under implementation, the plan has already laid the groundwork for safer water management, combining risk prevention and environmental conservation measures on key infrastructure for the island.