The Lake

When the eruptive activity of the entire volcanic complex of Vico ceased (about 100,000 years ago), the torrential rain and the waters rising from the subterranean springs filled the basin, thereby originating the Lake. In the beginning, and for thousands of years, the extension of the lake was much bigger: the water level reached almost the rim of the crater, with the peak of Mount Venere arising out of the north-east area of the lake, like a peninsula. It maintained this conformation for thousands of years, until the work of man started to modify it. At first the Etruscans, and then, after centuries, the Farnese family contributed to the decrease in its water level. The water level was decreased by approx. 20 meters through a man-made underground channel. It is not known whether the authors of such a work were the Etruscans or the Romans; without a doubt, the water level of the lake was decreased before the construction of the road called Cassia Cimina, dating back to the imperial period. Then, around 1500, the Farnese restored the channel, the present-day streamlet Vicano, further decreasing water level of the lake by three more meters, and regulating its level with a sluice - still existing.

The decrease in the water level left a noteworthy extension of cultivable lands uncovered, thereby encouraging the settlement of small communities of farmers and shepherds. Nowadays the Lake has a surface area of approx. 12 sq.km, 8.2 of which fall under the municipality of Caprarola, which are part of the Natural Reserve. It has a perimeter of 18 km, an average depth of 22.2 metres and a maximum depth of 49.5 metres. In order to protect both the lake ecosystem as a whole and the potability of its waters, the use of boats with internal combustion engines on the lake is forbidden.

Thanks to its peculiar biological purity, the Lake shelters an outstanding fauna: its waters are rich with numerous species of fish, such as the pike, which can grow up to remarkable size, the common whitefish, the tench, the perch, the eel.

With regard to the aquatic mammals, we must sadly report the disappearance of the otter, which lived in the Lake until the middle of the '60 and nowadays it is extremely rare, and the recent colonization of the Lake by the nutria, a rodent imported by South America that has spread in the wild in all of central Italy. But the distinguishing feature of the lake fauna lies in the presence of a rich waterfowl population, for which the Reserve represents one of the most important areas of wintering and resting in the entire region. During the winter season, for about 5 months, the Reserve provides shelter and nourishment to more than 5000 specimen (see under censuses), such as coots, different species of wild ducks as the tufted duck and the pochard, the so-called diving ducks that live where the water is deep and dive to feed on the algae growing on the bottom of the lake. On the contrary, the dabbling ducks, as the mallard, the common teal, the garganey, the Northern pintail, the Northern shoveler and the gadwall, live around the reed-beds, where the water is shallow. In the open water of the lake it is easy to find many Caspian gulls and black-headed gulls, especially during the winter season.