Hydraulic invariance

Rainfall management has become more problematic in recent decades due to the hectic growth of urban areas and climate change, which have led to an increase in extreme weather events. To cope with this scenario, a new approach to urban rainwater management is needed.

The Lombardy Region has recently introduced into its legislative system (see Regional Law 15 March 2016, no. 4 and subsequent acts) the principle of hydraulic and hydrological invariance, through which the hydrological impact of territorial transformation activities is to be reduced.

Aware of the importance of this issue at an environmental level, we have dedicated an office to the issue of hydraulic invariance to assist the municipalities involved in the drafting of simplified hydraulic risk documents and municipal hydraulic risk management studies (pursuant to art. 14 of Regional Decree no. 7/2017) and to carry out design activities for hydraulic invariance interventions (pursuant to art. 3 of Regional Decree no. 7/2017) for works of public interest within the territory concerned.

We also collaborate with various research bodies to draft studies and analysis relating to urban rainwater management. The projects we are working on include:

• FLOOD-HIDE: study aimed at assessing the potential use of agricultural land and rural channels for rainwater rolling;

• SMART-GREEN: research project to develop a model for optimising the use of green infrastructures on a territorial scale in order to mitigate the negative effects of flood outflows;

• SiRIC: hydrological invariance information system and municipal hydraulic risk management.