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Santa valley



The Campotto valleys are fresh water basins used as an expansion tank in the water drainage system of the lower Bologna plains tributary to the Reno river. In this area flow the rivers Idice, Quaderna and Sillaro, the channels Lorgana, Della Botte, Menata and Garda, which flow into the Reno in Bastia. In case of a swell of one of the rivers or channels the waters are temporarily drained in embanked basins (expansion tanks) whose surface, in Campotto, covers about 850 sq m and can store about 30,000,000 cubic metres of water. Waters are drained in the tanks during the swells and then discharged, via water draining pumps, in the Reno river. The Campotto expansion tanks are divided in three sections: Cassa Campotto (400 hectares), Valle Santa (250 hectares), Cassa Bassarone (200 hectares) which was permanently flooded in 1983.

particularly interesting from the nature point of view is the wet meadow on the South (30.37 hectares), flooded in 1995 with the funds granted by regulations 2078/92/EEC; vegetation is still developing yet fauna features remarkable specimens.
The basins have been permanently flooded although the water levels suffer from significant fluctuations because of water collection and summer evaporations that cause drying of wide areas. The soil is calcareous clay of alluvial origin.

The Campotto valleys are what remains of the ancient Argenta and Marmorta valleys. These wide freshwater marches started forming in the 12th century when the Primaro Po, whose bed had already been raised and was full of deposits, was no longer able to receive the waters from the many Apennine streams that flowed there. The flooding waters of the streams and of the Primaro generated a large water body south of the Primaro, a water body that was reclaimed only in the early 20th century.
Valle Santa is the Southernmost section of the Campotto expansion tanks and it is used as a floodway of the waters of the channels Menata and Garda and the rivers Idice, Quaderna and Sillaro.



The open waters are dominated with a vegetation of high relevance from the floral point of view value (Sint. Nymphaeetum albo-luteae) including hydrophytes that root on the water body bottom but have leaves and flowers floating on the surface (Nymphaea alba, Nuphar luteum, Polygonum amphibium), together with fully submerged species (Myriophyllum verticilatum, Ceratophyllum demersum). This association, over the last decade, has decreased remarkably because of the grazing pressure of the coypou, growing stronger in the Lower Po Valley.

Valle Santa, compared to Cassa Campotto-Bassarone, features a more widespread association of Typha angustifolia (Sint. Typhetum angustifoliae). In addition to the previously described associations the spot is dominated by marsh reed (Phragmites australis), are scattered in a mosaic-like pattern while in more shallow waters Sint. Phragmitetum vulgaris is more common. in less fauna-disturbed environments vegetation composition also features Alisma Plantago-aquatica, Sagittaria Sagittifolia and Iris Pseudoacorus. Along the embankment that closes to South of Valle Santa's water draining pump up to the East border with the Sillaro the vegetation mostly features Bromus Erectus, Gallum Verum, Euphorbia Cyparissias, Salvia Pratensis (Sint. Brometalia Erecti), (Corticelli 1999).

There are also rarer species: Hottonia palustris, Utricularia australis, Oenanthe aquatica, Sagittaria sagittifolia, Salvinia natans, Senecio paludosus, Thelypteris palustris. The area also features the following Emilia-Romagna Region protected species: Nymphaea Alba, Orchidaceae. while the river edges are home to riparian woods dominated by Salix alba.



Due to the closeness of the basins the fauna of Cassa Campotto-Bassarone and Valle Santa are rather similar and therefore we will deal with them at the same time. One of the most important features is the presence of the main Italian nesting colony of cormorants (252 couples in 1994), housed on the dead willows in Bassarone and then moved to the trees in the Traversante at the end of the '90s. Other birds nesting in the area are the grey heron (first nesting in 1987, 65 couples, and 1994), purple heron, black crowned night heron.

This environment is very important to help overwintering the Eurasian coot, mallard, gadwall, common pochard (747 individuals in 1997), Northern Shoveler, black crowned night heron (60 individuals) and Cormorant.

In the reed groves in Val Campotto the bittern has also been nesting for ages, though in very small numbers because of the management of this area that often clashes with the development of this important habit. The reed groves are also deeply connected to other interesting species: little bittern, purple heron, Western marsh harrier, little crake, spotted crake, Savi's warbler, bearded reedling.

It is also worth mentioning the nestings of Ferroginous Duck, the occasional nesting of Northern Shovelers and the nesting attempts of the Greylag Goose (Costa 1998, Pagnoni 1997, Toso et al. 1999).

Come and visit us
Valle Santa features an about 8 km circular path with birdwatching huts, open to the public free of charge. The Museo delle Valli di Argenta (Argenta valleys museum) is located inside the Casino di Campotto along the Via Cardinala road and is open to the public from Tuesday to Sunday. The Centro di Documentazione Storico Naturalistica (Natural and History Documentation Centre) hosts an essay on the evolution of the territory, fauna and flora of the area. In 1992 the museum was awarded the Council of Europe Museum Prize for the best natural museum of the year (phone 0532/808058). From the Museum it is possible to take guided trips to the Western part of the Traversante woods and Cassa Campotto-Bassarone, phone 0532 808059.


Typology Wetlands, fresh water
Cartography Regional Map, scale 1:25,000: 222 NE; 222 NO; 204 SO; 204 SE
Extension 261 ha
Municipality Argenta
Management Consorzio Bonifica Renana: convention with the Municipality di Argenta and Po Delta Park




Hydrographic restriction on the Expansion Tank pursuant to Royal Decree no.3267/’23.
Landscape preservation restrictions pursuant to Law no. 1497/1939 and environmental preservation restrictions pursuant to Law no.431/85, currently under the restrictions of Law Decree no. 490/1999.
Wildlife preservation oasis called Valli di Argenta e Marmorta, pursuant to Del C.P.269/9330 of July 18, 1977.
Ramsar Area called “Valle Santa” (261 hectares) established by Ministry Decree of May 9, 1977, published on Official Journal no. 216/09 of August 08, 1977.
Valle Santa is part of the Station “Campotto d’Argenta” of the Po Delta Park pursuant to Regional Law no.27/1988 and is part of the land layout plan in the Station Territorial Plan Del C.C. 132/17096 and 28/08/1991 (Area B and Area C with the recent restorations of the West).
SPA (IT4060014) pursuant to DIR 79/409/EEC (1713 hectares) and SCI (IT4060001) pursuant to DIR 92/43/EEC (1922 hectares).
SCI (IT4060001) called “Valle Santa, Valle Campotto” pursuant to DIR 92/43/EEC (1922 hectares) which in turn includes a SPA (IT4060014) called “Valle Santa e Valle Campotto” (1713 hectares) pursuant to DIR 79/409 EEC.




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