Hydraulic approach to Navigli canal daylighting in Milan, Italy

tThe daylighting of the ancient Navigli canal system, that encircled Milan medieval downtown over thecenturies, is addressed under the municipal commitment towards fully restoring the functional scheme.The program involves both urban planning and architecture to merge the multifaceted issues arisingat different scales into a unified design, let alone a number of concerns in both human sciences andtechnology. Hydraulics is the major driver to address the design process throughout the several spatialscales involved, so the program requires an innovative approach in order to determine water quantity andquality standards under the updated perspective of landscape, recreational and transportation objectivesof the program. Hydraulics must ensure maintenance of proper hygienic conditions, visibility of watersurface from different viewpoints in the urban landscape and navigability by small cruisers. To this effect,the mathematical model of the canal system reported here demonstrates how one can achieve optimalityof flow rate in the re-opened canal by a simulation approach of scenario-driven options, these includingthe number, location and operating rules of the locks needed to control water levels and transportationfluxes. The model also includes the assessment of inflow availability in both terms of water quantity andquality from the mayor tributary (i.e. Como lake via Adda River) throughout the existing irrigation channel(Naviglio Martesana). The outflow is finally shown to be consistent with the current conveyance of thehistorical canal (Naviglio Pavese) that conveys the combined outflow of Navigli system, this including theinflow from Lake Maggiore throughout the Naviglio Grande canal and the Adda supply throughout theNaviglio Martesana canal. The results provide the ensemble of hydrologic and hydraulic operational rulesto restore navigation capability of the canal system, and to accomplish with land planning, architectureand social requirements of the restoration program, these including hydro-energy exploitation of therestored canal system. The approach demonstrated by the Milan case study can constitute therefore aguideline for daylighting projects of artificial canal systems in historical areas.