The lake of Ancipa, also called "Lake Sartori" is an artificial basin in Sicily. On the Nebrodi mountains, a few km from Troina, it marks the border between the provinces of Enna and Messina. The lake was born following the construction of a dam (called "San Teodoro") to block the Troina torrent in order to produce electricity. Its construction, financed by the Sicilian Electricity Authority, took place between 1950 and 1952, creating a reservoir with a maximum capacity of 30 million m³. The works were carried out by the companies SOGENE and Lodigiani. On December 6, 1950, the works were marred by a disaster due to a firedamp explosion in the tunnel under construction near the dam with as many as 13 victims, some of whom perished in the generous attempt to extract the unconscious comrades inside. Later the lake water was also used for irrigation and drinking purposes. The current (2013) manager is ENEL SpA

The "Ancipa" is the highest lake in Sicily, with 944 m asl and constitutes one of the major resources for the water supply of central Sicily, supplying drinking water to 13 municipalities in the Enna province including the capital and to other towns in the Nisseno area and of Catania. During periods of drought there were significant drops in the water level of Ancipa and in 2006 it was reduced to just one million cubic meters causing a very serious water crisis in much of inland Sicily.

More recently, the lake has been the subject of a substantial investment which has led to the anti-seismic safety of the dam through the construction of some buttresses and the strengthening of the dam body with the elimination of the cracks produced over time. All this brought the maximum capacity of the reservoir to 50 million m³. The works began in 2009, entrusted to the Notari company and also involved the restoration of the water supply tunnel to the power plants which had been inactive for a very long time. In the first months of 2012 ENEL restarted the production of electricity, for a total of over 50 GWh, of the hydroelectric plants of Troina and Grottafumata which draw their water resources from the Ancipa dam^.

The waters of the reservoir are treated in the Troina purification plant, managed by Siciliacque, before being introduced into the aqueducts of the cities served.
Legambiente has obtained the management of 17 hectares of ENEL territory in which it organizes various initiatives to bring people closer to nature.
It is surrounded by beech and downy oak woods, which are home to a large number of life forms.