Evaluation of the ecological status of natural lakes in Spain: overview of the works performed by the cedex for the implementation of the Water Framework Directive

Abstract

This paper presents an overview of the work that has been done by the CEDEX for the implementation in Spain of the Water Framework Directive on water bodies belonging to the lake category. Firstly, the current national lake typology was developed according to the system B of Water Framework Directive: 30 types of natural lakes were defined according to 9 factors. Next, a selection of reference sites was done based on 9 criteria. After the contrast with River Basin Administrations, up to 70 lakes were selected as possible reference stations. Afterwards, an ecological assessment system has been developed for natural lakes, which includes a selection of metrics for biological, physical and chemical, and hydromorphological quality elements, and sampling and determination protocols. For all these metrics, reference conditions and ecological status class boundaries for each type of lake have been defined, based on the available data of the monitoring networks, scientific data, and expert judgment.