The main goal of the project is to develop a Cascade Flushing Flow Programme ('SICMEC') based on the analysis, integration and modelling of both physical processes and economic parameters of the river basins draining into the Ribarroja Reservoir (River Ebro). The SICMEC represents the starting point for restoration of the hydrosedimentary dynamics of the highly regulated rivers Segre and Cinca and, consequently, optimise the flushing flow programme of the Lower River Ebro that has been operational since 2002. We propose: (i) to design experimental releases from the main reservoirs in these two catchments, (ii) to continue the experimental flushing flow releases in the lower Ebro, and (iii) to examine natural floods that occur during the course of the project. For each of these three elements, the fundamental physical processes of flood routing, sediment transport and morphosedimentary adjustments of the riverchannel will be examined. We will use standard monitoring techniques in hydrology (e.g. Doppler sensors to measure flow velocity) and fluvial geomorphology (e.g. depth integrating samplers and turbidity probes), together with the most recent advanced techniques for assessment of morphosedimentary responses (e.g. terrestrial laser scan and photogrammetric techniques) and sediment transfer downstream from reservoirs (e.g. remote sensing). The cascade design of SICMEC aims to increase the availability of water resources for use in flushing flows from the Ribarroja Dam as well as enlargement of the current programme of artificial releases to its main tributaries, releases which enhance flow and sediment routing through the reservoir and reduce water and sediment residence time within it. The project will also assess the opportunity costs of withdrawing water for the flushing flows and analyse measures to improve efficiency of water management so as to ameliorate the economic impacts of the experimental floods. For this we propose to use economic evaluation methodologies and cost-efficiency analysis, integrated within River Basin Management Plans.

A Flushing Flow in the lower Ebro River (Flix Dam).

Finally, we will develop a decision support tool based on the integration of physical and economic elements. As it will be built around environmental effectiveness and cost-benefit criteria, this tool will allow the evaluation and comparison of different flushing flow options in the rivers Segre, Cinca and lower Ebro. We intend that SICMEC will serve as a tool to transfer methodologies and results to other drainage basins in the Iberian Peninsula and also to other Mediterranean catchments.