Eight years after the disaster: Are new pipes and stones at the Torrent de ses Planes enough?

Eight years after the disaster: Are new pipes and stones at the Torrent de ses Planes enough?

Key question: Does the planned redesign really make the torrent safe — or are we just shifting the risk?

Early in the morning in Sant Llorenç: construction vehicles start up, a moped rumbles up the Carrer de sa Marina, two women argue about the diversion behind the corner café, and on the bank of the Torrent de ses Planes there is the smell of damp stone. It is here that work now begins, intended as the response to the tragedy of the October 2018 flood. Nine million euros are flowing into the project, four culverts will become ten, and the discharge capacity is to increase from 105 to up to 500 tonnes of water per second. That is the sober tally — and a promise to residents.

But the sober tally is not the whole story. Eight years of delay have left their mark: suspicious questions, additional technical demands and the memory of 13 people who died back then. Officials have admitted that planning was blocked for a long time; the responsible water authority raised objections in 2023, and only after new expert reports did things move forward. Such delays change the perspective: measures that begin today must be effective for decades — at a time when heavy rainfall events can arrive faster and with greater intensity.

Why doubts remain: the plans are based on calculations of the most intense rainfall of the past 500 years. That sounds robust, but climate and land use change the rules. Model calculations are only as good as their assumptions: how do dense development in the catchment, altered soils or new sealing surfaces affect outcomes? And who ensures that the culverts will not be clogged within a few years by washed-up material?

Technically the idea is clear: a previous "funnel effect", explains a lead engineer, caused the water to back up and overflow. More culverts, consolidated retention volumes and reinforced banks are intended to ease this bottleneck. Natural stone walls will be preserved, so the character of the landscape will not be fully industrialized. That matters to many: walls and dry-stone construction are part of the island's identity.

What has been underemphasized in public debate so far: maintenance, accessibility and clear responsibilities. A larger cross-sectional profile only helps if it remains free. The municipality and the Consell must provide binding maintenance plans: regular cleaning of screens, inspections after storms, immediate removal of debris. Without this, any new capacity will be reduced sooner or later.

Practical additions that need not be costly: installation of gauge sensors with mobile connectivity linked to emergency centers and local AEMET warnings; clearly signposted escape routes and meeting points in the town center; annual evacuation drills for schools and care homes; simple, robust trash racks in front of the new culverts that can be easily emptied. Such measures significantly reduce residual risk.

Thinking further: retention areas and catchment basins above the village would absorb peaks. That does not mean every space must be concreted; small, decentralized retention areas and reforestation in upper catchments dampen the initial surge. Such solutions require coordination with landowners, agricultural operations and the forestry administration — so it is not just about concrete and bridges.

The political lessons are harsh: after a catastrophe everyday memory shifts quickly. The mayor and the island council president welcomed the start of construction; the president apologized for the delays. What matters is that decision-making processes become more transparent in the future. Who is responsible for which phase, which budgets are reserved for maintenance, who checks the simulations? These questions must be answered openly, otherwise frustration will return when the next heavy rain comes.

On the ground you can feel a mix of relief and scepticism. On the square in front of the town hall older men talk about how the streets flooded in previous storms; a shopkeeper on the diversion says business suffers because of the works, but she hopes her grandchildren will be able to play more safely later. Such voices show: safety is not only a technical issue, it is everyday life and trust.

A concrete timetable that politics and administration should publish now: an annual maintenance plan with fixed deadlines, a digital gauge and alarm network, a verifiable budget item for follow-up work, regular independent audit reports on hydraulic assumptions, and an open participation process for affected neighbours. Also: agreements with agriculture to reduce surface runoff and funding for small-scale retention projects.

Conclusion: the works at the Torrent de ses Planes are necessary and technically well thought out — more culverts, greater capacity, stabilized banks are the right components. But technology alone is not enough. If planning, construction and future care are not understood as one package, the next flood and the next anxious waiting at the riverbank are threatening. Those who build today must simultaneously assume responsibility for tomorrow. Otherwise the project will remain just a better insurance certificate on paper while people keep their brooms and sandbags at the ready.