Chiavica Emissaria dewatering pump

NAME: Chiavica Emissaria (outlet sluice)

LOCATION: Porto Viro (Ro)

ORIGINAL CONSORTIUM OF BELONGIN: Consorzio della Bonifica Polesana (consortium for the restoration of Polesine) (1890-1970)

DATE OF CONSTRUCTION: 1896-1898

HISTORICAL NOTES:

According to the excavation project for the Padano Polesano manifold (1889), in 1896 the consortium for the restoration of Polesine began with the construction of a great five-light masonry sluice with movable iron gates at the mouth of the Po di Levante. The structure had two purposes: the first one was to allow the Padano Polesano manifold to drain naturally and the second one to prevent the rising of high tides. Moreover, the upper part of the sluice was a road bridge that connected Porto Levante and the fishing valleys to Donada and Loreo. The construction works were directed by engineer Carlo Marchi.

After a few decades, in spite of the regular checks carried out by the Consortium, the weather and the chemical reaction of the salt water had deeply damaged both the wooden and the metal parts of the sluice.

There was an immense danger that high tides would be able to break through the sluice barrier, therefore, a radical restoration was essential. The restoration was carried out between 1938 and 1939 and involved not only the replacement of the gates and the reinforcement of the structure, but also the renovation of the upper walkway.

At the end of the 1950s, the subsidence of the land and the consequent overflowing of the tides made it vital to raise the building, which was commissioned to the Sottovia company (Brescia) according to the project of the 20^th of November 1958 and a further evaluation on the15^th of October 1959 signed by engineer Gian Maria Siviero.

At the time, the rains and the coastal storms of April 1958 worsened and the situation became dire, therefore, the nearby dewatering pump was designed and built on the same day (the 15th of June 1958). Since it was to be only temporary, it consisted of a building to house 20 Pellizzari electric pumps (supplied by the Ministry), a transformation cabinet, a reinforced concrete structure to bridge the right bank of the Po di Levante, a thermal storage unit and annexes. The construction was carried out by the Zilli company from September onwards and the first five pumps assembled by Officine Fregnan (Contarina) began to work on the 11^th of November.

Between 1964 and 1965, the dewatering pump was stabilised by connecting all the pumps, which had previously been partly powered by generators, to the national electricity network and installing a transformer. On that occasion, masonry work was carried out to modify the building, and the engine personnel’s house was completed.

Index

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Project funded by Regione del Veneto – L.R. 5/09/1984 n. 50, art. 44 – DGRV n. 618 del 11 maggio 2021 e n.1411 del 12 ottobre 2021 – Decreto del Direttore della Direzione Beni Culturali e Sport n. 325 del 27.10.2021

Photos Alberto Bonatti