The hydropower development of the Someșului valley took place in two distinct stages. The first phase ended between 1969 and 1977, with the completion of the hydropower plants fed by the Fântânele, Tarnița and Gilău I reservoirs. In the second stage, started in 1979, four more hydropower plants were added, of which only one, located between the Tarnița and Gilău, has a supply lake. The other three hydropower plants - Gilău II, Florești I and Florești II - operate on the basis of a canal system.
Lake Gilău, located at the foot of Mount Gilău, was formed in 1972, behind a 10-meter high dam, built at an altitude of 410 meters. The waters of the lake stretch for a distance of about 1 kilometer, having an area of about 70 hectares, a depth of 9 meters and a useful volume of 2 million cubic meters. It was designed mainly to supply drinking water to the municipality of Cluj-Napoca and to ensure the water requirements for the flotation of the ore from Căpușu and the industrial area from Aghireșu.
The fish fauna of the lake is extremely varied, mostly resulting from the fish species existing in the bed of Someșului Mic before the flood. The dominant species are the bream, the barbel and the bream, and in 1962 the bream was introduced.
Downstream of the dam, in 1975-1976, the most modern trout farm in the country was built, which produced the material needed for the annual repopulation and depopulation of the area's reservoirs and rivers.
Lake Gilau is also a popular place for recreational activities such as swimming, kayaking, windsurfing and hiking. On the shores of the lake is a complex recreation base that offers facilities for camping, picnicking and other outdoor activities.
At the tail of the lake, you can see the confluence of Someșului Rece and Someșului Cald, each of which is followed upstream by a road.
Someșul Mic is formed by the confluence of Someșul Cald and Someșul Rece, made at a distance of 5 km upstream from Gilău commune. At the same distance is the place called Bogdăneasa, where, according to legend, lived a young crai named Bogdan, married to a beautiful lady. After his death in battle, the lady gathered the herds left after the looting by the enemies and went up to the mountain, where she gave birth to two twin boys. They became shepherds, and one summer, because of the drought, they moved the flocks further up the mountain.
While in a clearing, they fell into a deep sleep, and a beautiful girl from a small thicket appeared, warning them that a witch wanted to take revenge on them. The night before, the witch had sent them sleep, but the girl, in love with the boys, stole part of the sleep to protect them. The witch decided to send the sleeper to them again, then her brother to take their sheep, and finally a stag with a horn on its head, which was to kill them. The girl taught the boys how to cut the stag's horn, giving them a leaf to keep them awake.
The next night, the youngest boy stayed awake and defeated the witch's brother. The next evening, the older brother managed to break the stag's horn, but he forgot that he was enchanted and turned into a spring. The younger brother sought it out and, touching the horn, he too turned into a spring. Thus, Someș was born from the spring of the older brother, flowing smoothly, and Criș from the spring of the little one, flowing quickly in search of the lost brother.
Source: Tourist itinerary Alba Iulia - Cluj-Napoca - Oradea (Ministry of Tourism, 1982)
