CENTAUR® Prevents Flooding at a World Heritage Site in Coimbra, Portugal

Overview

CENTAUR® was deployed within a combined sewer network in Coimbra, Portugal, to reduce flood risk in a steep urban catchment that includes a World Heritage Site. By intelligently controlling in-sewer flows and creating equivalent storage capacity, the system has reduced flooding in the historic town square during storm events.

The solution required minimal civil engineering works and provided a low-cost, low-carbon and minimally invasive alternative to conventional flood alleviation schemes within a sensitive historic environment.

The Client

Águas de Coimbra is responsible for the management of water supply and wastewater services across the municipality of Coimbra. The organisation aims to deliver a high-quality service while adopting innovative and sustainable approaches to managing urban water challenges, particularly within environmentally and historically sensitive areas.

Client Benefits

• Flooding reduced at a World Heritage Site and surrounding city centre
• Improved control of peak flows within a steep urban catchment
• Effective use of existing sewer storage without network enlargement
• Minimal disruption and visual impact in a historic setting
• Low-cost and low-carbon solution compared to conventional civil engineering approaches
• Autonomous operation with no reported downtime or maintenance requirements

The Challenge

Coimbra is a medium-sized city located with steep urban catchments, making it particularly vulnerable to intense rainfall and rapid runoff. The historic town centre, including the main town square and key tourist areas, had experienced repeated flooding in recent decades.

Opportunities for conventional flood mitigation were limited by the dense urban environment, the historic and visually sensitive nature of the area, restricted space for new infrastructure, and budget constraints.

A solution was required that could significantly reduce flood risk without extensive excavation or permanent alterations to the historic cityscape.

The Solution

CENTAUR® is an autonomous, in-sewer flow control system that uses real-time level data and an intelligent control algorithm to dynamically regulate wastewater flows, creating equivalent storage capacity within existing sewer infrastructure.

In Coimbra, two large-diameter interceptor sewers upstream of the town square were identified as providing suitable storage capacity. Hydraulic modelling demonstrated that installing CENTAUR® on a single interceptor would be sufficient to reduce flooding during large storm events. Following successful operation, a second CENTAUR® system was installed on a parallel branch to provide additional resilience during extreme rainfall.

The two systems now operate in parallel, reducing water levels at a common downstream control point upstream of the town square. In the first three years after commissioning, CENTAUR® controlled more than 50 rainfall events and reduced flooding in the town square.

Civil works were limited to the replacement of a manhole cover slab and the installation of a small roadside kiosk to provide power and communications to the sewer, resulting in a minimally invasive and highly effective solution.

Testimonial