The squandering, depletion and devastation of the Adriatic resources are becoming a trend that could have severe ecological, spatial and economic consequences. In all the larger towns where wastewaters are drained into sewers, we can find evidence of the inadequacy of the sewage system as a whole, this being one of the major factors in the disruption o f the environment. The large discrepancy in the equivalent load and quantities of municipal wastewaters during the tourist season and the low season is a decisive factor in the choice of optimum purification systems, and in the choice of local strategies in achieving sustainable development.