The hydraulic safeguard of the city of Milan: the Canale Scolmatore di Nord-Ovest

The hydraulic safety of the city of Milan has always been a primary objective in the management of the territory of Regione Lombardia. The alluvial phenomena that, more and more frequently, have interested the territories of the metropolitan area and immediately upstream, towards the north-west (director Milano-Gallarate-Varese) and towards the north (Brianza), have brought over time huge economic losses and determined in the local populations a perennial sense of anguish. The complexity of the so-called “Milanese hydraulic node”, connected to the ferocious anthropization that has characterized these territories for centuries, and especially during the years of the “economic boom ” (fifties and sixties), has always constituted an enormous obstacle for the administrations, both for problems in management and in economic terms. At the end of the past century the increasing emergency requirements have only begun to find concrete answers from the institutions, initially by means of the Piano di Assetto Idrogeologico (ex L. 183/89) and then by means of the Laws issued by Regione Lombardia (since 1998 competent in matter of territorial defence). Today, the hydraulic order of the safety system of the city of Milan is under adaptation and the realization of the planned and programmed participations will guarantee facing the hydraulic emergency during events with great return periods. In this paper the peculiarities of this hydraulic system and the institutional instruments and the solutions apt to guarantee the functionality of the system in front of the changed territorial scenes have been described