MOSE construction site monitoring

Published on 08-02-2022

Monitoring of the environmental effects of the construction of the MOSE in the Venice lagoon

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Programme or Providing body: Venice Water Authority – Interregional Superintendency for Public Works for Veneto, Trentino Alto Adige and Friuli Venezia Giulia, through its concessionaire Consorzio Venezia Nuova
Project title: Studi B.6.72 B/1-B/13. Survey activity for monitoring the effects produced by the construction of the works at the lagoon inlets
Acronym:MOSE construction site monitoring
Duration: 2004-20194
Project budget: 17.800.000 €
Contact person in CORILA: dabala@corila.it
Keywords: monitoring, construction sites, inlets, MOSE system

Abstract

The safeguarding of the Venice lagoon has its fulcrum in the interventions for the defense of all the inhabited areas of the lagoon from high tides.

Specifically, the works for the MoSE System consist of a series of mobile barriers, i.e. arrays of gates to be built at the three inlets, capable of isolating the lagoon from the sea during high tide events, above a predetermined altitude.

The construction of the MoSE System requires the execution of large engineering works to be performed in particularly precious from an environmental point of view and fragile areas of the Venetian coast. Indeed, these sites are designated as Sites of Community Importance according to the Directive 92/43 / EEC and SPA according to Directive 79/409 / EEC, therefore falling within the “Natura 2000” network. In addition, the Venice lagoon, identified as IBA (Important Bird Area) 064 “Venetian Lagoon”, is one of the most important areas of interest for the protection of avifauna.

In addition, habitats of fishing interest (both for repopulation and capture) as well as areas of tourist exploitation (with different densities) are present close to the lagoon inlets. Finally, big ships that “feed” the economy of the city and of a large area of the Northeast pass through the three inlets.

On behalf of the Venice Water Authority, CORILA carried out an extensive monitoring program of the effects of the MOSE construction sites on the environmental matrices and on the economy of those sectors that could potentially be impacted by the execution of the works.

Overall objective

The Monitoring Plan is essentially aimed at preventing any possible environmental damage and, in its implementation, it pursues a dual purpose:

provide a prompt feedback in the event that the maintenance of the expected level of environmental impact for the construction site activities is not respected, in order to allow for the implementation of proper and prompt countermeasures;
provide objective elements to know and demonstrate the effective impact of construction site activities on the environment, with respect to the variability of environmental conditions (or the economic situation) and distinguishing the different origins of the phenomena, to prepare and manage the mitigation or compensation measures eventually needed.

Main results

“Monitoring” is not just “measuring”; on the contrary, the Monitoring Plan includes possible suggestions to limit the pressure of the works, the careful examination of the mitigation actions performed at construction sites and possible suggestions for compensation measures, when needed. Therefore, over the years, an effective feedback procedure has been put in place between the monitoring researchers and the operators in the MoSE construction sites, in agreement with the public administrations.

The MoSE system is probably the largest civil work that have occurred in a lagoon and the monitoring program is arguably one of the largest ever occurred in such an environment. The experience gained so far is useful to identify some general rules that may be applied elsewhere.

The monitoring activities carried out so far allowed to deeply characterize the system at the inlets, to define the different phases of the construction work, to identify, where possible, the causal links of the perturbations detected and hence to address limits and corrections towards the construction site, by proposing, where necessary, mitigations and compensations measures.

Therefore, from one side monitoring allowed to prevent the environmental damages by addressing limits and corrections to the construction site works, as well as mitigations and compensations measures where necessary. From the other side, it allowed to collect a series of information that will be useful in the subsequent management phase, when the MOSE system will be realized. Also, with regard to the economic activities monitored, it was verified the absence of real impacts and methodologies and actions useful for assessing the perception of the impacts by the operators were established, as well as a solid information base, usable in the following phases.