Conso II hydroelectric development specific analysis of the environmental compatibility of the Conso II Project in relation to the Hydrological Plan of the Miño-Sil Hydrographic Demarcation (TT.MM. Vilariño de Conso and Viana do Bolo, Orense).

TAXUS Environment has developed an integrated environmental characterization of the Cenza and Bao reservoirs, aimed at assessing the environmental compatibility of a reversible hydroelectric project with the environmental objectives of the hydrological planning and with the framework established by Article 4.7 of the Water Framework Directive.

The methodology combined the analysis of historical information with specific field campaigns, in situ measurements, sampling, laboratory analysis and environmental simulations. The work included the study of the oscillation regime of the water masses, limnological and physicochemical characterization, analysis of the trophic state and ecological potential, study of suspended solids, and granulometric and chemical characterization of sediments.

The biological communities present were also evaluated by monitoring phytoplankton, macrophytes, benthic macroinvertebrates and ichthyofauna, the latter using direct fishing techniques and molecular analysis of environmental DNA. As part of the study, simulations were also carried out to assess the possible mobilization of sediments and the risks associated with accessibility to the reservoir basin in different oscillation scenarios.

The results obtained made it possible to rule out significant environmental impacts on water quality, ecological potential, biological communities and the safety of the environment. Overall, the study concludes that the action analyzed is compatible with the environmental objectives applicable to the Cenza and Bao reservoirs, preserving the principle of non-deterioration set out in the Water Framework Directive.