Le rôle de la conception et de la gestion de la voirie dans la réduction des rejets urbains de temps de pluie

The role of the conception and management of the road network in the reduction of urban, pollutants by rainy weather

Centre d'Etudes Techniques de l'Equipement du Sud-Ouest, C.E.T.E., Groupement Aquitain pour la Recherche et l'Innovation en Hydrologie, GARIH

Abstract

The streaming on the urban road network is one of the principal water pollution causes. The deposit and the streaming processes during the rainy episodes must be better known if we want to intervene efficiently against this pollution.

The experimental site on road Roustaing in Talence corresponds to a very urbanized reservoir slope of 4 ha whose urban network supports heavy traffic. The equipment installed there permits a continuous measurement of the rain and the evolution of the pollution streaming on the pavement. At the same time, the deposit accumulation on the road is measured in order to know its variability in accordance with the time interval between two cleanings.

Another approach consists of reducing the streaming. The draining trench is one of the techniques employed for this. Its efficiency is tested on a road in an activity zone which comprises heavy traffic. The quantitative and qualitative aspects are the following: continuous measurement of the rain and its flow, measurement of the water pollution at the end of the trench, migration possibility of the pollution to the ground. An intervention at the source by an optimisation of the road cleaning (frequency and machine type) or by a better management of the flow will permit a considerable limitation of the impact of urban pollutants by rainy weather.