Technical-economic modelling of integrated water management: wastewater reuse in a French island

An integrated technical-economic model is used to address water management issues in the French island of Noirmoutier. The model simulates potable wat er production and supply, potable and non potable water demand and consumpt ion, wastewater collection, treatment and disposal, water storage, transpor tation and reuse. A variety of water management scenarios is assessed throu gh technical, economic and environmental evaluation. The scenarios include wastewater reclamation and reuse for agricultural,and landscape irrigation as well as domestic non potable application, desalination of seawater and b rackish groundwater for potable water supply. The study shows that, in Noir moutier, wastewater reclamation and reuse for crop irrigation is the most c ost-effective solution to the lack of water resources and the protection of sensitive environment. Some water management projects which are regarded a s having less economic benefit in the short-term may become competitive in the future, as a result of tightened environmental policy, changed public a ttitudes and advanced water treatment technologies. The model provides an a ppropriate tool for water resources planning and management.