Project stories

Contrast to hydrogeological instability: the intervention on the Potenza river

The project in brief

Contrast to hydrogeological instability: the intervention on the Potenza river (Macerata)

The story of the project

The violent floods that hit the province of Macerata in June 2023, also forcing many people to evacuate their homes, highlighted the urgent need to secure the waterways that run through the Marche region.

Bank stabilization works on the Potenza River (Ph. Picchionews)

One river in particular has always posed significant risk: the Potenza River, which originates at the foot of Mount Vermenone and winds for about 90 kilometers until it reaches the coast at Porto Recanati. The progressive narrowing of the riverbed, water flow obstructed by tall trees, breaches in some sections of the embankment, and poor maintenance of the regular water flow have constituted a serious threat over the years. This threat has recently been exacerbated by the increase in extreme weather events caused by climate change. Additionally, an error made in the 15th century by Benedictine monks, who diverted the river's natural course 8 kilometers from its mouth, has led to significant erosion of the embankments over time, consequently increasing the risk of flooding in the final stretch of the Potenza Valley.

All this highlights the importance of the measures implemented to reduce the hydrogeological risk in the Macerata area, which began in 2020 and are now largely completed. Specifically, these measures involve the intervention to reduce the hydraulic risk of the Potenza River, funded under the 2014-2020 Regional Operational Programme of the European Regional Development Fund by the Marche Region. This falls under the Axis "Promote adaptation to climate change, prevention and management of climate-related risks such as erosion, fires, floods, storms, and drought".

The intervention was divided into two projects. The first project, concerning the reinforcement of the riverbanks from the river's mouth to Molino Gatti, in the municipalities of Potenza Picena and Recanati, was funded with an amount of 700,000 euros, which was fully disbursed, minus minimal savings, by the end of 2023. The second project, which received the larger amount of 2 million euros (with over 1.5 million already disbursed for completed works), focuses on the stretch from Ponte Sant’Antonio to the source. Its completion is expected by the end of 2024.

The overall intervention aims at the arrangement and revitalization of the areas bordering the Potenza River for approximately 50 kilometers, which is more than half of the entire course from the source to the mouth. The ultimate goal is to provide long-term protection to local communities against the increasingly frequent extreme weather events capable of causing significant damage to the area.

Removal of logs carried downstream by the river flood (Ph. ANSA)

More specifically, the works have involved selectively cutting vegetation to improve water flow and reduce the risk of blockages that could cause flooding, reinforcing riverbanks to prevent erosion and collapses, enhancing water discharge capacity during floods, renovating existing bridges, and constructing new, wider, and more resilient bridges. For instance, bridges in locations such as Castello and the cemetery of Fiuminata have been improved. Additionally, the removed vegetative material has been repurposed for constructing palisades and other protective devices, following a circular engineering approach.

Before the start of the works, several studies and analyses were conducted, including topographic surveys, geognostic and geotechnical investigations, chemical and physical analyses, as well as botanical and faunal studies. These efforts were aimed at preserving the biodiversity and the quality of the river ecosystem.

For the implementation of the interventions, it was also necessary to engage with private landowners. As highlighted by technical officials from the Civil Engineering Department of Southern Marche, in an interview conducted by the students of the ASOC EcoSystem team of Macerata, which monitored the project in 2022, "interaction with landowners took place through an amicable agreement, acknowledging the sovereignty of the embankment recognized by civil law, and therefore restoring the continuity that had been lost with the construction of certain anthropic works. Additionally, the company Autostrade took charge of the embankment continuity restoration works in some sections, as a third lane for the highway was being constructed".

According to the project calculations, the reconstruction of the hydraulic model of the Potenza River, made possible by cohesion funds and the synergy among institutions, organizations, and citizens, will triple the flood capacity of the river in the most at-risk inundation areas. This will significantly reduce the risk of floods and thereby protect inhabited areas and infrastructure. It reflects an approach towards sustainable and responsible management of the valuable water resources of the region.