Heavy rainfall in Ibiza on Tuesday, 3 November 2026, caused another wastewater discharge into Ibiza Port, affecting the area where passengers board ferries connecting the island with Formentera. Following the incident, the Balearic Government has called for progress towards separating rainwater drainage from the wastewater sewerage network, identifying the shared infrastructure as a key factor behind the recurring overflows.

The Department of the Sea and Water Cycle explained to Periódico de Ibiza y Formentera that the large volume of rainwater entering the sewerage system overloaded the infrastructure. At certain moments, the port's stormwater holding tank was unable to evacuate all the incoming water, resulting in wastewater overflowing into the port.

The incident highlights the vulnerability of Ibiza's existing drainage infrastructure during periods of intense rainfall, particularly in the port area, where the management of rainwater and sewage remains closely connected.

Heavy Rain Overwhelms the Port's Stormwater Tank

The discharge occurred on Tuesday morning, 3 November, after persistent rainfall affected Ibiza and Formentera.

The affected area was the passenger boarding zone for ferries travelling between Ibiza and Formentera, close to the maritime station and the Burger King building. Images shared by a local resident showed wastewater emerging in the port area.

According to the Balearic Government, the volume of rainwater entering the sewerage network was so substantial that the port's stormwater tank could not evacuate all the incoming flow at certain moments.

The tank is designed to help regulate the volume of water entering the system during periods of heavy rainfall. However, when the incoming volume exceeds the infrastructure's capacity to evacuate it, overflows can occur.

The Government said the joint venture responsible for operating the tank, formed by FACSA, Islasfalto and Transportes Bufí, had reported that pumping operations were eventually able to clear the accumulated flow once the volume of incoming water decreased.

The operator indicated that the overflows had therefore stopped.

Govern Identifies the Shared Sewerage Network as the Underlying Problem

The Department of the Sea and Water Cycle pointed to the existing configuration of Ibiza's drainage infrastructure as a fundamental issue.

Rainwater enters the same network used to transport wastewater. During intense rainfall, this additional volume can overload the system and place pressure on pumping facilities and stormwater infrastructure.

The Government argues that preventing similar incidents will require progress towards separating the two networks.

Under a separated system, rainwater would have its own drainage route rather than entering the wastewater sewerage network. This would reduce the volume of water passing through the sewage infrastructure during heavy rainfall and help prevent overflows.

The department indicated that the separation is expected to advance through investments included in Ibiza Town Council's new water-service contract with Aqualia.

ABAQUA Requests a Technical Report on the Pumping Systems

Despite the explanation provided by the operator, the Balearic Water and Environmental Quality Agency (ABAQUA) has requested a written report from the company responsible for managing the stormwater tank.

The report is intended to verify what happened during the incident, particularly the operation of the two pumping systems.

This technical assessment will help establish how the infrastructure responded to the exceptional volume of water entering the network during Tuesday's rainfall.

The request is an important part of the follow-up because the Government has acknowledged the overflow while seeking further technical information about the performance of the pumping equipment.

Aqualia's Investments Expected to Improve Ibiza's Water Infrastructure

The separation of rainwater and wastewater is one of the improvements expected under Ibiza's new municipal water contract with Aqualia.

The new concession includes substantial investment in the city's water infrastructure, with planned works covering the renewal and improvement of sewerage networks, hydraulic capacity and the development of separate rainwater drainage systems.

The aim is to reduce pressure on the existing sewerage network, improve its ability to manage heavy rainfall and minimise the risk of wastewater overflows.

However, the separation will require infrastructure works and investment. The fact that it forms part of the new contract does not mean the entire system has already been separated or that the risk of further overflows has disappeared.

VOX Calls for Immediate Solutions

The latest incident has also prompted a political response. VOX Ibiza has called on the Town Council to implement immediate solutions, arguing that the problem has affected the city for years.

The discharge once again raises questions about the capacity of Ibiza's infrastructure to cope with intense rainfall, particularly in areas where rainwater and wastewater continue to share the same network.

With the Government requesting a technical report and the new water contract expected to deliver improvements, attention will now turn to the findings of the assessment and the implementation of the planned infrastructure investments.

For residents, workers and passengers using the port, preventing further wastewater discharges into the harbour remains an important environmental and public infrastructure challenge.