The coastal management plan of the Natura 2000 Network in Cantabria (currently in environmental formalisation) has identified the main risk factors for maintaining habitats and species of community interest in a good conservation state and for guaranteeing the physical processes needed for the correct development of ecosystems in its estuaries. As with other estuaries in the EU, many of the threats come from hydromorphological alterations. These may result from productive uses (e.g.dikes for agroforestry use) as well as from educational uses (e.g. ethnographic use of tidal mills). The alteration of tidal inundation regimes and the changes in the sedimentary characteristics derived from these pressures favour the spread of non-native species (e.g. Baccharis halimifolia), which adds a new pressure to the preservation of biodiversity here. The general objective of this project is to improve the conservation status of habitats and species of community interest through the implementation of actions to restore the ecological functionality (hydrodynamic) of the estuaries. The environmental sustainability of the project will be further guaranteed through the promotion of the COEXISTENCE of the preservation elements of Red NATURA 2000 with the development of different anthropic uses: cultural-educational, tourist and productive.