Audit urges tougher federal stance on Rhone flood project

The Swiss Federal Audit Office has praised the Federal Office for the Environment’s oversight of the third Rhone correction but called for a tougher approach towards the canton of Valais, SRF reported.

The project is intended to give the Rhone more space in the cantons of Valais and Vaud, make the river more natural and protect the surrounding plain, people and infrastructure from flooding. Approved by both cantons in 2016, it is expected to cost about 3.6 billion Swiss francs, with the federal government providing 2.1 billion francs.

The project has been politically contentious from the outset because of its cost and its additional land requirements for agriculture and settlements. In 2022, Valais State Councillor Franz Ruppen commissioned a study that concluded the project was oversized and based on excessively severe assumptions about flood levels. The Valais government subsequently decided in 2024 to revise the remaining measures by the end of 2026, without involving the federal government or the canton of Vaud in the decision.

Because the federal government is financing a large share of the project, the Federal Audit Office examined how the Federal Office for the Environment had performed its supervisory role after Valais announced the revision.

The audit office gave the environmental agency a largely positive assessment. Mischa Waber, head of a division at the Federal Audit Office, said the agency had actively participated since the revision was announced. It had also reduced the federal government’s financial risk by suspending payments to Valais since 2022.

However, the audit office said the agency needed greater enforcement power. It should represent the federal government’s interests in the revision more persistently and escalate matters if necessary, the report said. The agency must ensure that Valais informs the federal government at an early stage about the progress of the revision, Waber said.

The audit office also called for a coordinated overall view because several federal agencies are involved in the project. The Federal Office for the Environment should lead efforts to ensure that all federal interests are properly represented. The agency has accepted the audit office’s recommendations.

The third Rhone correction is described as Switzerland’s largest flood protection project. It covers 162 kilometres of river and is intended to protect more than 100,000 people while preventing an estimated 10 billion francs in flood damage. The project will take several decades, with some construction already under way and other measures planned from 2040.

The revision in Valais is due to be completed by the end of 2026. If the revised project differs too substantially from the original, a new proposal and approval by the national parliament will be required. The audit office said the additional costs and delays resulting from the revision could not yet be quantified.