The Economics of Nature‑Based Solutions for Wastewater Treatment is a research report that develops a cost‑benefit analysis (CBA) framework tailored to evaluate nature‑based wastewater treatment solutions such as constructed wetlands and other green systems. It was produced under the EU‑funded MULTISOURCE project and is designed to be flexible for both developed and developing contexts, with a modular structure allowing analysts to adapt cost and benefit functions to local conditions and objectives. The methodology includes direct treatment costs, economic returns, and externalities such as pollution reduction and ecosystem benefits. It also discusses land opportunity costs and the need for context‑specific assessments, and aims to inform planning through integration with analytical tools for technology selection and project design.
