The role of natural ponds in controlling the urban runoff regime

Urbanization, beside an increase in impervious cover, is often associated with a reduction of natural ponds and wetlands along streams. This process is poorly studied in urban hydrology literature, but contributes to modify the hydrological regime of urbanizing catchments by reducing the storage capacity available to retain runoff. This communication presents a research using data from seven gauging stations in a catchment (50 km²) of the Brussels Region. First, these data are used to compare the hydrological regime of urbanized and forested catchments. Then, a set of scenarios are simulated over a forested subcatchment. Scenarios include an increase in the impervious cover of the catchment and the removal of existing ponds, in order to test the respective role of each of these processes.