Italiano Deutsch English

Cassa Campotto and Bassarone





The Campotto Valleys are freshwater pools used as casse, or detention basins, for the drainage system of the low plain surrounding the Reno River and Bologna. 

The Idice, Quaderna and Sillaro River course through this zone, while the Lorgana, Della Botte, Menata and Garda Canals flow into the Reno in the locality of Bastia.  When the rivers and canals overflow, water is temporarily introduced into the dammed pools (detention basins) at Campotto.  These cover a surface area of about 850 ha and hold about 30,000,000 cubic meters of water.  The waters are introduced during times of flooding to be flushed away successively, via hydraulic pump, into the Reno River.

The Campotto detention basins are subdivided into three compartments: Cassa Campotto (400 ha), Santa Valley (250 ha) and Cassa Bassarone (200 ha), re-flooded in 1983.  Although the basins are permanently flooded, waters levels fluctuate widely as a consequence of collection and summertime evaporation, which results in the desiccation of ample surface area.  The chalky loam soil is alluvial in origin.

The Campotto Valleys are what remain of the ancient Argenta and Marmota Valleys.  These extensive freshwater swamps began to form in the 12th century, when the riverbed of the Po di Primario—raised and encumbered by sediment—could no longer hold the water flowing into it from various Apennine streams.  The overflow from these streams and from the Primario formed a great expanse of water to the south of the Primario that was only drained at the beginning of the 1900s.  Cassa Campotto and Bassarone, positioned to the south of the Reno, are used to divert overflows from the Reno and from the Lorgana and Della Botte Canals.  



The open waters are dominated by vegetation, of high naturalistic value (Sint. Nymphaeetum albo-luteae), consisting of hydrophytes rooted into the depths, but with leaves and flowers floating on the surface (Nymphaea alba, Nuphar luteum, Polygonum amphibium).  Mixed with the hydrophytes are completely submerged species (Myriophyllum verticilatum, Ceratophyllum demersum).  This community has declined sharply in the last decade due to strong pressure from the grazing of nutrias, constantly increasing in the lower Padan plain.  In the southeast sector, scrublands of Typha angustifolia (Sint. Typhetum angustifoliae) mix with the previous vegetation.  Vegetation dominated by reeds (Phragmites australis), which are widespread in shallower waters (Sint. Phragmitetum vulgaris), alternates with these communities to form a sort of mosaic.  In calmer waters, Alisma plantago-aquatica, Sagittaria sagittifolia and Iris pseudoacorus contribute to the community. 

Several species that are threatened on the national level grow here (Libro Rosso della Flora d’Italia): Hippuris vulgaris, Hottonia palustris, Leucojum aestivum, Oenanthe aquatica, Sagittaria sagittifolia, Salvinia natans, Senecio paludosus and Thelypteris palustris.

Leucojum aestivum, Nymphaea alba and Orchidaceae are the species growing here that are protected by the Emilia Romagna Region. 



Given the proximity of the basins, the distribution of fauna in Cassa Campotto-Bassarone and Santa Valley are very similar and shall be treated together here.  Of particular importance is the presence of Italy’s principle Cormorant nesting communities (252 pairs in 1994), settled in the dead willows of Bassarone.  Colonies have moved into the trees of the Traversante Forest since the late 1990s.

Also nesting here are the Grey Heron (first nest in 1987; 65 pairs by 1994), Purple Heron and Black-crowned Night Heron.  The site is moreover quite important to the wintering of Coots, Mallards, Gadwalls, Common Pochards (747 individuals in 1997), Northern Shovelers, Black-crowned Night Herons (60 individuals) and Cormorants.

Until the early 1990s, the vast swampy ponds of Cassa Campotto were settled by the most important colony of Whiskered Terns on the Italian peninsula, today drastically reduced to only a few individuals.  The Eurasian Bittern has also historically nested in the reed beds of Campotto Valley, although in scarce numbers due to management efforts that have sharply contrasted with the development of the reed beds.  Other species of great conservation interest are tied to the reed beds: Little Bitterns, Purple Herons, Western Marsh Harriers, Little Crakes, Spotted Crakes, Savi’s Warblers and Bearded Reedlings.  The nesting of the Ferruginous Duck; the occasional nesting of the Northern Shoveler; and the attempts at nesting of the Greylag Goose are also notable (Costa 1998, Pagnoni 1997, Toso et al. 1999).


To visit

One can visit the Campotto and Bassarone basins by following the roadways and trails of the western embankments, where two small towers for the observation of avifauna stand out.  Visits to the interior are only permitted with accompanied by Museo delle Valli workers.

The Museo della Valli di Argenta, or “Museum of the Argenta Valleys,” is found inside the Casino di Campotto along Via Cardinala.  It is open to the public from Tuesday to Sunday.  The Center for Naturalistic Historical Documentation features an exhibit on the evolution of the territory and its flora and fauna.  The museum won the Council of Europe’s prize for best naturalistic museum of the year in 1992 (tel. 0532/808058).  Guided excursions from the museum through the western part of Traversante Forest and to the Campotto and Bassarone basins are possible. 


Typology Freshwater wetlands
Cartography CTR 1:25.000: 222 NE; 222 NW; 204 SW; 204 SE
Extension Cassa Campotto (400 ha) - Cassa Bassarone (200 ha)
Municipality Argenta
Property Renana Reclamation Consortium
Management Renana Reclamation Consortium: agreement with the municipality of Argenta and the Delta Park



Hydraulic restriction as a Detention Basin pursuant to R.D. 3267/’23.

Environmental restriction pursuant to L. 431/85, currently subject to the restrictions of D.L.490/1999.

Faunistic Oasis known as “Argenta and Marmorta Valleys,” pursuant to Del C.P. 269/9330 of 18/07/1977.

Ramsar Zone known as “Campotto and Bassarone Valley” (1303 ha), pursuant to DM 12/10/1978.

The Valleys are included within the limiting boundaries of the Park of the Delta del Po, pursuant to L.R. 27/988, and within the limiting boundaries set out by the Territorial Station Plan, Del C.C. 32/17096 of 28/08/1991 (Zone B).  The “Campotto and Bassarone Valley” Ramsar Zone (1363 ha), instituted by DM 21/10/1978 and published in GU n. 360 of 28/12/1978, is included in Zone B and C of the Park, within which hunting is forbidden.  

Special Protection Zone (IT406004) known as “Santa Valley and Campotto Valley,” pursuant to DIR 79/49/EEC (1713 ha) and Site of Community Interest (IT4060001) known as “Santa Valley, Campotto Valley” pursuant to DIR 92/43/EEC (1922 ha).



To be constantly updated on the activities of the Management Body for Parks and Biodiversity - Po Delta

Subscribe Unsubscribe



Scientific Website of the Po Delta Park