This publication documents the co-design process of the Business Roadmap and policy recommendations (BRM) for sustainable development of the Mar Menor and surrounding Campo de Cartagena, and of the System Dynamics model to evaluate the impacts of the BRM on Key Performance Indicators (KPI) under different scenarios of socioeconomic, political and climate change. After presenting the co-design process and the modelled impacts on KPI it provides a short overview of featured results. The Business Road Map and Policy Recommendations (BRM) consists of the following 4 milestones and related 14 solutions: (I) Rural ecotourism: 1) The promotion of rural ecotourism activities. (II) Coastal ecotourism: 2) The promotion of coastal ecotourism activities. (III) Sustainable agriculture: 3) Implementation of nutrients, soil, and water retention measures 4) Reduction in fertilizer use 5) Denitrification of brine wastes from groundwater treated for irrigation 6) Decrease in agricultural water demand per hectare (i.e. 10% of decrease by default in the model) (IV) Integrated sustainable management: 7) Control of the extension of irrigated areas 8) Promotion of environmental education 9) Control of the number of groundwater wells (i.e. maximum 500 wells by default in the model) 10) Promotion of small (<10MW) (agro)photovoltaic facilities 11) Surface water pumping from the Albujón ephemeral stream 12) Control of other point sources of pollution to the lagoon 13) Groundwater pumping and treatment 14) Increase in sea water desalination amount (twice the BAU value by default in the model) A flipbook version of this publication can be found here at the Knowledge Exchange Platform of the COASTAL project.