Blue Lakes

The Blue Lakes are a natural complex on the northern outskirts of Kazan, in the Vysokogorsky district of Tatarstan, near the settlements of Shcherbakovo, Goluboye Ozero, and Krutushka. This small system of karst lakes, with its almost perfectly clear mineralised water, has long been one of the city’s recognisable natural landmarks: people come here to swim, dive, and walk through the valley of the Kazanka River, in whose old channels the lakes lie.

The first scientific description of the lakes was given in 1829 by Karl Fuchs, a professor and later rector of Kazan University, as well as a local historian and physician. At the time, the lake was called Shcherbakovskoye, after the nearby village. In 1972, Bolshoye Goluboye (Great Blue) Lake was given the status of a natural monument, and in 1994 the entire surrounding area became a regional state nature reserve covering 1,910 hectares, even though the surface of the three lakes themselves covers only about 0.3 hectares.

The system consists of three unconnected bodies of water — Bolshoye Goluboye (Great Blue), Maloye Goluboye (Small Blue), and Protochnoye (Flow-through) lakes. The basins formed on the site of karst sinkholes in limestone and dolomite around two hundred years ago and are fed exclusively by underground springs, releasing up to six hundred litres of water per second into the Kazanka. Bolshoye Goluboye Lake has two deep funnels — the Great and Small Puchina (Abyss), eighteen and six metres deep respectively; springs saturated with gypsum well up from the bottom of the Great Puchina.

The water temperature barely changes throughout the year, staying around three to eight degrees Celsius, which is why the lakes cool the Kazanka in summer and keep it from freezing downstream in winter. The water’s bluish tint comes from mineral calcium-sulphate salts and bluish silt deposits on the bottom; an optical effect makes the bottom appear much closer than it actually is. No fish live in the cold, mineralised water, but the shores are home to species listed in Tatarstan’s Red Data Book — the milky-white planarian, the water scorpion, the greater spotted eagle, and the European bee-eater.

Until the mid-twentieth century, the energy of the springs feeding the Small Lake was used first by a water mill and later by a small hydroelectric station. In 1928 the Kazanka washed away the barrier separating the lake from the river, and the lake temporarily shrank, but after restoration work its level returned to normal. Today the Small and Great Lakes have jetties and changing rooms; the site is a popular year-round swimming spot for winter “walruses” and a training ground for divers from several federations, and nearby operates the “Krutushka” sanatorium, where local mud has traditionally been used to treat skin conditions.

The Blue Lakes remain one of the few pockets of wild nature within a major city and a protected area with rich flora — forests of birch, aspen, and pine, and dozens of species of shoreline plants. For Kazan residents and visitors, the site combines a natural landmark with a tradition of winter swimming and active recreation, while for scientists it is a rare example of a karst hydrological system preserved in an almost natural state next to a city of over a million people.