Discussion Paper | Discussion Paper | Discussion Paper | Discussion Paper | Hydrol. Earth Syst. Sci. Discuss., 11, 12315–12364, 2014 www.hydrol-earth-syst-sci-discuss.net/11/12315/2014/ doi:10.5194/hessd-11-12315-2014 © Author(s) 2014. CC Attribution 3.0 License. This discussion paper is/has been under review for the journal Hydrology and Earth System Sciences (HESS). Please refer to the corresponding final paper in HESS if available. Simulating long-term past changes in the balance between water demand and availability and assessing their main drivers at the river basin management scale J. Fabre1, D. Ruelland1, A. Dezetter2, and B. Grouillet1 1CNRS, HydroSciences Laboratory, Place Eugene Bataillon, 34095 Montpellier, France 2IRD, HydroSciences Laboratory, Place Eugene Bataillon, 34095 Montpellier, France Received: 30 September 2014 – Accepted: 15 October 2014 – Published: 4 November 2014 Correspondence to: J. Fabre (
[email protected]) Published by Copernicus Publications on behalf of the European Geosciences Union. 12315 Discussion Paper | Discussion Paper | Discussion Paper | Discussion Paper | Abstract The aim of this study was to assess the balance between water demand and availabil- ity and its spatial and temporal variability from 1971 to 2009 in the Herault (2500 km2, France) and the Ebro (85 000 km2, Spain) catchments. Natural streamflow was evalu- 5 ated using a conceptual hydrological model. The regulation of river flow was accounted for through a widely applicable demand-driven reservoir management model applied to the largest dam in the Herault basin and to 11 major dams in the Ebro basin. Urban wa- ter demand was estimated from population and monthly unit water consumption data.