Varenna Stream, Varenna Valley, Genoa, Genoa, Liguria, Italyi

Regional Level Types
Varenna Stream	Stream
Varenna Valley	River Valley
Genoa	Commune
Genoa	Metropolitan City
Liguria	Administrative Region
Italy	Country

The Varenna (Voëna in Ligurian) is a stream whose course develops almost entirely in the territory of the municipality of Genoa, except for a short stretch at the head of the valley, which belongs to the municipality of Ceranesi. The stream, which crosses the valley of the same name, is the third-longest watercourse in the city of Genoa, after the Bisagno and the Polcevera, and the fifth-largest in catchment surface area.

The stream originates (with the name of Rio Vaccarezza) from springs located beneath the ridge between the Lencisa pass and Mount Proratado (928 m above sea level), on the Liguria-Po watershed between the valleys of the Polcevera and Varenna (on the Ligurian side) and that of the Stura di Ovada (on the Po side).

It takes the name of Varenna in the Camposilvano area, at the confluence of the Vaccarezza stream and the Grillo stream, which also originates from Mount Proratado. The Varenna in its course touches the hamlets of San Carlo di Cese, Carpenara and Granara and flows after 11 km on the coast between the districts of Pegli and Multedo. The hydrographic basin has a surface area of ​​21.96 km² and is characterised by a main axis arranged in a north-south direction perpendicular to the coast. The maximum altitude of the basin corresponds to Mount Penello (995 m), located along the ridge on the right side of the valley.

The contiguous river basins are those of the Chiaravagna, Molinassi and Rostan streams to the east, Polcevera to the north, and Leira, Branega, San Pietro and Rexello to the west.

In its short course it collects several streams, but only a few of them, all on the right side, form lateral valleys of significant dimensions.

On the right orographic side, from mountain to valley:

Gandolfi: 2.4 km long, it originates from Mount Foscallo (987 m) and creates one of the largest side valleys of particular naturalistic interest; it flows into the Varenna downstream of San Carlo di Cese.

Taggia: a short stream (1.45 km) that originates from the Costa del Corno.

Cantalupo: the main of the tributaries, is made up of various streams that originate from the southern slopes of the Penello, Fontana Buona and Punta del Corno mountains; it flows in a north-south direction parallel to the course of the Varenna, into which it flows at Tre Ponti. The main branch of the stream measures 5.2 km.

On the orographic left, from upstream to downstream, there are only short watercourses: Rio dei Corvi, Lavino, Poma and Rozzano. The largest of these (about 1.5 km) is the Rio dei Corvi.

Like most of the watercourses in Liguria, the Varenna and its tributaries are characterised by a torrential regime, with a very modest flow in the summer months, so much so that it is often almost dry in this period. In the autumn months, floods are possible which have sometimes caused damage, flooding and landslides, as happened during the flood of 23 September 1993.

The average annual flow at the mouth is 0.8 m³/s, with a minimum in August (0.15 m³/s) and a maximum in November (1.23 m³/s), corresponding to the period of maximum autumn rainfall, concentrated in October and November. A lag of about a month is observed between the rainfall trend and the flow rate, due to the gradual release of water from the ground and the aquifers.

The maximum flood flows, calculated with mathematical models, are 291 m³/s with a return time of 50 years, 374 m³/s with a return time of 200 years and 438 m³/s with a return time of 500 years.

Other Databases

Wikipedia:	https://it.wikipedia.org/wiki/Varenna_(torrente)
Wikidata ID:	Q4008701

Other Regions, Features and Areas containing this locality

References