Parco regionale dei Laghi Suviana e Brasimone

About

The Suviana and Brasimone lakes regional park (Italian: Parco regionale dei laghi di Suviana e Brasimone) is a regional park and protected natural area in the Bolognese Apennines, in Emilia-Romagna, northern Italy. It lies in the Metropolitan City of Bologna, near the border with Tuscany, and extends around the artificial reservoirs of Lake Suviana and Lake Brasimone, together with the surrounding forests, ridges, villages and hydroelectric infrastructure. The park was established by Regional Law no. 38 of 14 April 1995 and covers 3,329.89 hectares in the municipalities of Camugnano, Castel di Casio and Castiglione dei Pepoli. Its territory includes two large reservoirs created for hydroelectric purposes, a largely forested mountain landscape, historical settlements such as Bargi, Baigno, Badi, Stagno and Chiapporato, and the Natura 2000 site IT4050020 "Laghi di Suviana e Brasimone". The park is unusual among protected areas of the Apennines because its landscape is closely connected with twentieth-century energy infrastructure. The difference in elevation between Brasimone and Suviana is used by the Bargi hydroelectric power station, a pumped-storage plant commissioned in the 1970s...

The park occupies a central sector of the mountains south of Bologna, between the valleys of the Brasimone stream and the Limentra di Treppio. Its southern boundary follows the watershed near the Tuscan border. The ridge between the two principal reservoirs is formed by Monte Calvi, the highest summit of the park at 1,283 m (4,209 ft), and by Monte di Stagno.

The two main lakes are artificial reservoirs at different elevations. Lake Suviana lies at about 465 m (1,526 ft) above sea level, while Lake Brasimone lies at about 845 m (2,772 ft). This difference in altitude later became central to the pumped-storage hydroelectric system linking the two basins.

The landscape is mostly wooded. Mixed oak woods, beech woods, chestnut groves and conifer plantations cover much of the slopes, while open meadows and former cultivated areas occur within the forest. Sandstone outcrops and steep wooded walls are visible along the western side of the main ridge and below the Brasimone basin, especially in the area known as the Cinghi delle Mogne.

One of the most characteristic scenic features of the park is the rocky front of the Cinghi delle Mogne, immediately downstream from the Brasimone dam. Here the left bank of the stream is dominated by steep cliffs showing regular stratification of turbiditic sandstones, with sparse vegetation of European hop hornbeam, manna ash, oak, sweet chestnut, beech and shrubs.

The cliffs of the Brasimone gorges provide habitat for raptors such as kestrels and peregrine falcons. Along the ridge, at about 950 m (3,120 ft) above sea level, is the Grotta delle Fate, a natural cave formed along a fracture in the sandstone layers, about 70 m (230 ft) long and 3 m (9.8 ft) deep, with specialised subterranean fauna.

Monte Calvi, the highest mountain in the park, has a steep western slope above the Limentra di Treppio valley, where mixed broad-leaved woods and conifer plantations are interrupted by sandstone outcrops. On the gentler eastern side, former fields and pastures are now colonised by bracken, shrubs and broom, while stone walls still mark old meadows and rural settlements.

Monte di Stagno is another major panoramic point. Its flat and windy summit offers views over Lake Suviana, the Limentra di Treppio valley, the Reno valley and several Apennine peaks, including Corno alle Scale, Monte Cimone, Monte Vigese and Sasso Balinello.

The park was created in 1995 to protect the natural and historical landscape around the two reservoirs and the surrounding Apennine territory. Traditional settlement in the area was based on small mountain villages, chestnut groves, woodland management, pastoral activity and local routes across the ridges. For centuries the local economy relied mainly on livestock, timber, charcoal production and chestnut cultivation.

From the early twentieth century the area was transformed by large public works connected with hydroelectric production. In 1910 works began on a dam near the Scalere mill, where the Brasimone valley narrowed and the stream formed a series of drops. The dam was also used for a new road linking Castiglione dei Pepoli with Riola through Camugnano, improving access to the Porrettana road and the Bologna–Pistoia railway.

The hydroelectric plant connected with the Brasimone reservoir was built farther downstream, near the old church of Santa Maria, where a second dam was built in 1917 to increase production. Ten years later the State Railways completed the Pavana reservoir, in the nearby Limentra di Sambuca valley, to provide electricity for the electrification of the Porrettana railway.

In 1928 works began on the damming of the Limentra di Treppio near Bargi and Suviana. The Suviana dam, completed in 1933, was described by the park authority as the highest dam then existing in Italy, at 97 m (318 ft). New roads and a cableway between Suviana and Porretta railway station were built to support construction and to transport cement. Water from Pavana was also conveyed into the new reservoir through an underground conduit.

At the beginning of the 1970s the two basins of Brasimone and Suviana were connected by penstocks and a plant capable both of generating electricity and of pumping water back to the upper reservoir. In the 1960s construction had also begun on the PEC experimental nuclear reactor project on the southern shore of Lake Brasimone; the project was abandoned after the Italian nuclear referendum of 1987.

Lake Suviana is one of the largest bodies of water in the Emilian Apennines. It has an approximate surface area of 1.5 km 2 (0.58 sq mi), a maximum depth of about 70 m (230 ft) and a capacity of about 46 million cubic metres. The reservoir was built between 1928 and 1932, taking advantage of the form and geology of the valley, which allowed a large quantity of water to be stored.

The lake has steep shores in many sections, and its water level varies according to the operation of the hydroelectric system. It is the more visited and equipped of the two main lakes. Tourist sources describe picnic areas, seasonal accommodation, bathing areas and outdoor activities such as windsurfing, sailing, rowing and sport fishing, subject to local regulations.

Lake Brasimone is smaller and higher than Suviana. It has an approximate surface area of 0.5 km 2 (0.19 sq mi), a maximum depth of about 29 m (95 ft) and a capacity of about 6 million cubic metres. Its waters are held by the Scalere dam, about 35 m (115 ft) high.

The dam was built at a narrow section of the valley, where the Brasimone stream enters its gorge and the valley sides are formed by solid sandstone. The reservoir flooded a broader basin where mainly clayey terrains crop out.

Compared with Suviana, Brasimone has a quieter and more wooded character. Its shores include small rest and picnic areas, and the lake is closely associated with forest walks, the surrounding mountain landscape and the ENEA research facilities on its southern side.

The two reservoirs are connected by the Bargi hydroelectric power station, a pumped-storage hydroelectric plant owned by Enel. The plant was commissioned in 1975 and has an installed capacity of about 330 MW. It uses the difference in elevation between Lake Brasimone and Lake Suviana, with a gross head of about 375 m (1,230 ft).

In generation mode, water descends from the upper Brasimone basin to the lower Suviana basin through the turbines. In pumping mode, water can be moved back from Suviana to Brasimone, allowing the system to store energy and support grid management. The hydroelectric system gives the park a strong connection not only with landscape conservation and recreation, but also with the history of energy infrastructure in the northern Apennines.