Tetra Tech CSO carried out the first conceptual study of the Louis Fargue, Clos de Hilde, Sabarèges, Cantinolle, and Lille catch basins in 2003. The study was part of the compulsory requirements to oversee future work on an integrated master plan for flood and pollution control in wet weather over a short period of time.

In 2005, a detailed study specific to the Louis Fargue catch basin (downtown Bordeaux and metropolitan area) served as the basis to produce a wet weather master plan to achieve both pollution and flood control goals. Detailed tasks included:

• Confirmation of the performance of the existing facilities;
• Mouse™ model update and validation (sanitary and drainage) and model conversion into InfoWorks™;
• Investigation of capacity constrained areas and anticipation of rehabilitation needs;
• Definition of the detailed potential solutions per sub-catchment basin;
• Validation of the operational plans and performance;
• Definition of the optimal implementation phases (prioritization);
• Budget planning and recommendations.

Following the studies, the detailed design and implementation of an intelligent RTC system with Csoft began in September 2009.A first implementation phase integrating seven regulation and retention structures, including two new infrastructures to be controlled through a central station, were commissioned in early 2013. It was also coordinated with extensive rehabilitation works at the wastewater treatment plant and the construction of a new storage basin by the Bordeaux Urban Community, while preserving storage availability upon flooding storms. The RTC system aims to reduce overflows to the Garonne River and optimize the use of the plant's new treatment capacities. The RTC system has been operating successfully since January 2013.

Highlights

Average % of CSO volume reduction:     68% (volume)                    82% (frequency)

Capital investment savings:                         $430M