This dataset includes the model developed by the H2020 COASTAL project’s MAL #4 for the Charente River basin and its coastal zone. It also includes the data necessary to perform model simulations and the data representing three development scenarios co-designed with local stakeholders to envision possible futures of the territory (cf. https://doi.org/10.5281/zenodo.7074941). The model, developed in system dynamics language (software Vensim), simulates the interactions between water management, shellfish farming, agriculture, population & tourism, and infrastructure development around their common water resource and under the influence of external uncertainties (climate and agricultural prices). The model was designed in order to identify and improve possible land-sea synergies between these activities, with the aim to reach a sustainable, robust and desirable future for the territory.