A network of ~100 streams and small rivers will be constituted in the 5 Research cities.


Toulouse is a thriving city in Southern France and part of the Toulouse metropolitan area with more than 800,000 inhabitants of which more than 100,000 are students. 

The urban aquatic ecosystems in Toulouse are of high relevance for OneAquaHealth: 1) in the South the two rivers Garonne and Ariege create a confluence, 2) both rivers originate in the near Pyrenean mountains (100 km south), 3) the united rivers flow as Garonne river through the city centre of Toulouse, 4) due to the hilly landscape in the South of Toulouse, many small often intermittent streams flow towards the Garonne, and 5) the Canal-duMidi, located in Toulouse, combined with the Canal de Garonne forms the Canal des Deux Mers, linking the Atlantic Sea and the Mediterranean Sea. The value of these rich urban freshwater ecosystem and its importance for urban life is planned to be enhanced by the Grand Parc Garonne urban project. The project aims to reclaim 32 km of riverfront to develop pedestrian and bicycle paths, enhance natural heritage, to reinforce the uses linked to water, and to develop new spaces for culture and conviviality. The project involves 7 municipalities covering 3,000 hectares.

Along the river system, several flood areas are marked, and a large part of it is currently protected in a regional park, which seeks further enlargement, also in concertation with the Grand Parc Garonne project. 

Due to the high population density, the river system is under high anthropogenic pressure through agricultural influxes, urbanisation, industrial development, and touristic activities. High nutrient pollution, plastic pollution, and urban pollution, together with increasing flood frequencies, have altered the ecosystem. Many studies have been carried out in the system regarding pollution, but assessment of ecosystem health and health risks for freshwater communities and the urban population are scarce. The available data will be complemented by newly collected data at sampling sites located along the smaller streams flowing towards the Garonne, the Garonne itself and the Canal-du-Midi

Current status of activities:

Second Local Alliance workshop:

The workshop took place on 23 January 2024. The consortium discussed various aspects of the project with the participants, in particular the One Health issue in relation to urban streams, the expectations of stakeholders and the possibility of setting up citizen participatory sciences. These exchanges were highly instructive and gave the project members a better understanding of the issues at local level, so that the project can best meet the needs of the people of Toulouse.

Organisation of the first Local Alliance workshop:

The first workshop to present the OneAquaHealth project for Toulouse took place on 20.10.2023. Several partners representing different categories of stakeholders were present and introduced to the objectives of the project and of the Local Alliance. (Nine stakeholders from various professional backgrounds are currently involved in the project).

Installation of mosquito traps on the different study sites:

As mosquito populations continue to grow in the Occitanie region—where Toulouse is located—exposing 90% of the regional population to the tiger mosquito (2022 figures from the Regional Health Agency), the OneAquaHealth team in Toulouse set up traps around the urban streams studied. The captures were fruitful, which will make it possible to analyse the dangers they represent for citizens living in various parts of the city.