Rainwater harvesting to control stormwater runoff in suburban areas. An experimental case-study

Guido Petrucci (1) , José-Frédéric Deroubaix (1) , Bernard de Gouvello (1, 2) , Jean-Claude Deutsch (1) , Philippe Bompard (3) , Bruno Tassin (1)

1 LEESU - Laboratoire Eau, Environnement et Systèmes Urbains
2 CSTB - Centre Scientifique et Technique du Bâtiment
3 DSEA - Direction des Services de l'Environnement et de l'Assainissement

On a 23 ha urban watershed, 10 km East of Paris, rainwater tanks have been installed on 1/3 of the private parcels to prevent stormwater sewer overflows. This paper investigates the macroscopic effect of rainwater harvesting on runoff, and thus the potential of this technique for stormwater source control. The analysis is performed using the SWMM 5 model, calibrated on rainfall- runoff measures from two measurement campaigns, before and after the equipment. The availability of two data-sets allows to point out changes in the catchment's behaviour. The main findings are that: (1) catchment's evolution, mainly caused by individual land-cover modifications, produces non-stationarity of the hydrologic behaviour; (2) the rainwater tanks installed, although they affect the catchment hydrology for usual rain events, are too small and too few to prevent sewer overflows in case of heavy rain events.

Mots clés: rainwater harvesting; source control; BMP; runoff; rainfall-runoff analysis; sewer overflows

Domaines: Hydrologie; Milieux et Changements globaux; Ingénierie de l'environnement

Guido Petrucci, José-Frédéric Deroubaix, Bernard de Gouvello, Jean-Claude Deutsch, Philippe Bompard, et al.. Rainwater harvesting to control stormwater runoff in suburban areas. An experimental case-study. Urban Water Journal, 2012, 9 (1), pp.45-55. ⟨10.1080/1573062X.2011.633610⟩. ⟨hal-00698564⟩