Vadskoye Lake (also Mordovskoye Lake, Vad Lake) — a karst lake in the selo of Vad, the administrative center of Vadskiy Municipal District of Nizhny Novgorod Region, approximately 110 kilometers from Nizhny Novgorod and 30 kilometers from Arzamas.[1][2] It lies in the channel of the Vadok River, a left tributary of the Pyana. It is fed by powerful upwelling karst springs — voclinas — above which the water does not freeze even in winter.[1] It is protected as a natural monument of regional significance; the current certificate of designation was approved in 2010, and the protected area covers 145.4 hectares.[3]

Origin and name

Unlike Svetloyar, the origin of Vadskoye Lake is not associated with legend: it is a karst sinkhole. Underground waters dissolved gypsum rock over centuries, forming basins and funnels, while the Vadok River, flowing through karst cavities, created underground tunnels; as the interconnected cavities filled with water, they merged to form the lake. The connection between the cavities is confirmed by the fact that when the outflow from Vadskoye is dammed, the water level simultaneously rises in neighboring, shallower karst water bodies.[4]

The double name is explained by the history of the lake's shores: in the 19th century, the settlement of Vad stood on the southern bank and the village of Mordovskaya on the northern bank; when they merged, the present-day selo of Vad was formed, giving the lake its name.[4] The word "Vad" itself is traced to the Mordva word "vat'" — water; another version holds that the name derives from the marshy terrain along the banks of the Vadok, which remains after spring flooding.[1] The Mordva lived near Vadskoye Lake for a long time, and many place names of Mordva origin have been preserved throughout the district.[1]

What the lake is like

The lake stretches 1.9 kilometers in length; its width in the dam section is one kilometer. The basin is complex, with deep areas and extensive shallows: the average depth even in the central part is around 80–90 centimeters. The water is clear, silting of the bottom is minimal, and sandy substrate is found almost everywhere. In the northwestern part, a section of a transverse dam extending from the northern shore has been preserved — a narrow peninsula approximately 150 meters long.[3]

In the eastern part stands a dam with an asphalt road along its crest. The dam raised the water level, and the lake united the Vadok and Vatma rivers; both exit through sluices. The area along the southern and southwestern shores is marshy, with cattails and reeds growing there.[3] The first dam on this site — the former monastery dam, an earthen one — was restored in 1938, and in 1967 it was replaced by a structure with reinforced-concrete gates; after the reconstructions, the lake acquired the triangular shape characteristic of a pond, with the dam forming its base.[4]

The voklina and the underwater cave

The lake's defining feature is its voklina — a deep karst funnel with a submarine spring at the bottom. Jets of water surge from it with such force that a noticeable convex "lens" forms above the surface, and the rings of waves spreading outward are visible from a great distance; underwater currents radiate from the voklina for some twenty meters, and the water above it does not freeze even in severe frosts.[4][1] The funnel itself is nine to ten meters deep, and from its floor a passage led off into an underwater grotto with depths of up to twenty-four meters and good visibility.[5] In certain parts of the lake the depth reaches twelve meters.[6]

There were two vokliny. One of them, overgrown with algae and sparse plants, collapsed in 1938 after the old monastery dam was restored. The surviving one was an enormous funnel with mosaic walls covered in blue-green algae; according to local history publications, there were only three such caves in freshwater lakes on the entire planet — one in Belgium, one in France, and this one.[4]

The non-freezing opening and clear water made Vad well known among divers from Nizhny Novgorod Region and other regions; in 2005 a hotel and dive center, "Vadskoy," opened on the lake's shore.[4]

Cave Collapse, 2007

The cave collapsed in mid-March 2007. Lyudmila Koryaeva, the administrator of the hotel that stood on the shore, recounted that on one of the warm days, toward evening, the water at the center of the lake began to churn violently and a dull thud was heard; several boats carrying fishermen were rocked by a wave, the water quickly turned murky, and the next day the usual patch of clear water on the surface was gone.[7]

On April 8, 2007, a group of divers from Nizhny Novgorod came to dive in the vaucluse spring and found no entrance to the cave. According to their account, the depth at that spot did not exceed seven meters, visibility at one meter depth was zero, and where a flat silty cave ceiling had previously been, there were now collapses with fresh clay walls; no lens of upwelling water was visible at the surface. Divers who had visited a week earlier had already encountered a significant cave-in: the nearly circular funnel of the entrance had turned into a narrow, wide-gaping slot. A group from Penza that arrived shortly afterward descended to eighteen meters in the funnel and hit a blockage with a narrow passage.[7]

Since then, the tunnels and entrances to the grottos have been inaccessible to underwater explorers; only a small basin remains of the cave, but the lake itself remains a recreational spot for divers.[5][6]

Nature Monument

The current protection instrument is the decree of the Government of Nizhny Novgorod Region dated July 23, 2010, No. 444, "On the Regional Nature Monument 'Vad Lake'," with an object passport, as amended in 2011 and 2015. Following an inventory of the Region's specially protected natural areas, the area of the nature monument was established at 145.4 hectares.[3]

The monument's designated purpose is the protection of the gene pool and cenofond — habitats of rare species and typical biocenoses of karst lakes — as well as scientific, water-protection, and recreational functions.[3]

Within the monument's territory, the following are prohibited: privatization and sale of land; pollution and littering; discharge of industrial, agricultural, and household wastewater into the lake and its tributary streams; construction; laying of utility lines; extraction of mineral resources; alteration of the hydrological regime; livestock watering; spring hunting; introduction of cyprinid fish species; and motorboat navigation. Dredging of bottom sediments is separately prohibited — except within a ten-meter strip near recreational zones and only from August 1 onward, subject to coordination with the authorized body. Permitted activities include amateur fishing with a rod and spinning rod, recreation and swimming, scientific research, and repair and reconstruction of hydraulic structures aimed at maintaining stable water levels in all seasons — provided a positive state environmental assessment is obtained.[3]

A 50-meter-wide buffer zone has been established around the monument along all its boundaries. Within it, the following are prohibited: plowing, livestock grazing, dumping grounds, cemeteries and livestock burial pits, application of fertilizers and pesticides, felling, off-road vehicle parking, tourist campsites, and campfires; permitted activities include, in particular, improvement of the beach area in the southeastern part of the lake. The territory is protected by the administration of Vad selo, and compliance with the regime is monitored by the Region's Ministry of Ecology and Natural Resources.[3]

Plants and Animals

The lake is heavily overgrown: submerged aquatic vegetation covers approximately 80 percent of the water surface — filamentous algae on top, intertwined with multicellular plants rising from the bottom, lesser duckweed, Canadian waterweed (Elodea canadensis), and stoneworts (Characeae); together they form floating mat "islands" of 500–600 square meters. Reeds up to three meters tall dominate the entire perimeter, forming a continuous impenetrable band; in the western part, broad-leaved and narrow-leaved cattail thickets grow densely alongside arrowhead and sedges.[3]

Four animal species listed in the Red Data Book of the Nizhny Novgorod Region have been recorded within the nature monument: the common tern (no more than eight pairs on the lake), the great crested grebe — a small colony of about four pairs in the western part — the grey heron (four individuals), and the common kingfisher, a solitary specimen of which was encountered at the fish farm pond. Among other waterfowl, the mallard and the black-headed gull have been recorded; along the shores — the common nightingale, the common whitethroat, the Eurasian blackcap, the marsh warbler, the northern lapwing, the corncrake, the whinchat, and the black kite.[3]

Reptiles present include the sand lizard and the grass snake; amphibians include the pool frog, the lake frog, and the common toad; dragonflies, beetles (Coleoptera), and Lepidoptera have also been recorded. The abundance of small mammals is low — no more than 5.5 percent capture rate per one hundred trap-nights, against a regional average of 18.8 percent.[3]

The Fish Farm and the Swans

To the east of the lake, beyond the dam, in the floodplain between the Vadok and the Vatma rivers, lies the Vadsky fish farm, which dates back to the 1950s. The hatchery breeds and then releases into grow-out ponds grass carp, common carp, silver carp, pike, trout, peled (Siberian cisco), nelma, and crucian carp.[3] In 2022, a Russian sturgeon and rainbow trout breeding facility opened on the basis of the Vadsky cooperative; the water welling up from the depths is considered safe here for both juvenile and market-size fish.[8]

Swans have become the symbol of the district: they winter on the lake at an ice-free polynya, raise offspring annually, and their population is growing. In March 2021, fish farmer Vladimir Klyushin broke open a polynya and pulled out a swan that had become entangled in an abandoned poacher's net; the bird was released into the Vadok.[9] Two swans swimming toward each other are depicted on the district's coat of arms, entered in the State Heraldic Register under No. 11026: the azure field is an allegory of the lake, and the swans represent its fauna.[10]

Ecology and the Present Day

The state of the lake has long been a concern for environmentalists. In 2018, the regional Ministry of Ecology attributed the silting and the loss of water-protection and recreational qualities to the large volume of pollutants entering with domestic wastewater: the shores have been densely built up since the eighteenth century, and runoff from cesspits, bathhouses, and kitchen gardens flows directly into the water. Askhat Kayumov, head of the Dront ecological center (which was listed in the register of NGOs designated as foreign agents from 22 May 2015 to 31 August 2017), Askhat Kayumov believed that only the removal of buildings from the shoreline would fully resolve the problem.[11]

In January 2020, the Ministry of Ecology included Vad Lake in the list of water bodies requiring dredging and clearance.[12] In July 2022, the head of the local government, Ivan Urayev, appealed to a State Duma deputy for assistance in cleaning the lake, noting that any remediation works would require a change in the lake's protected status.[8]

In April 2026 the district was contending with high water: the lake's hydraulic structures were continuously releasing water to handle the large volumes flowing through, yet in the night of 6–7 April the lake level rose and caused another round of flooding; the earthen dam on the Vadok had to be partially dismantled.[13] On 17 April 2026, a community clean-up day was held at the dam and in the villages along it as part of the nationwide "Water of Russia" initiative: around a hundred participants formed a clean-up chain, with the final point of the route being the clearing of the area around the Holy Springs.[14]

See also

The lake in the 1980s

By the 1980s the lake had come under severe economic pressure. In 1985 a fish-farming state farm, Vadsky, was established here, with its ponds located below the dam; under that enterprise's practices, the lake water was drained each winter to allow the bottom to freeze solid. That same year the Rodina collective farm began extracting bottom sediments — sapropel was dredged by a suction dredge — while the Krasnaya Strelka collective farm set up a summer livestock enclosure on the southern bank slope, and with the rains and spring snowmelt, streams of manure began flowing into the lake.

The banks and waters were polluted by household waste; karst sinkholes on the northern bank slope were turned into the district rubbish dump. In the forest above the lake, through which the Vadok flows, the water-protection zone was disregarded: trees were felled right down to the bank, heavy machinery tore up the turf, and fallen trunks choked the channel. At the point where it flows into the lake, the Vadok's channel had been churned up and compacted by a road laid across it: to avoid making a detour, the Krasnaya Strelka collective farm piled up an earthen dam here every year, which floodwaters and rainwater would wash into the lake, leaving only a barely visible trickle forcing its way through the narrow pipe beneath the road. The river was further polluted by the Lomovsky distillery in Arzamassky District, which discharged untreated effluent.

Environmental protection officials warned that this regime was leading not to the preservation of the lake as an intact ecosystem but to its destruction: the sole voklina would silt up, the water body would become shallow, overgrow with vegetation, and lose its rare plant species. The district branch of the All-Russian Society for Nature Conservation succeeded in 1988 in halting sapropel extraction by suction dredge.

Sources

  1. vad.nobl.ru (archive)
  2. Nizhegorodskaya Pravda — The most interesting tourist routes through Vadskiy District (archive)
  3. eco.nobl.ru
  4. putidorogi-nn.ru — Vad Lake (Nizhny Novgorod Region): location, photos, description (archive)
  5. ngounb.ru — Vadskiy District — V.I. Lenin Nizhny Novgorod State Regional Universal Scientific Library (NGOUNB) (archive)
  6. KP — Nizhny Novgorod (archive)
  7. vglubine.ru — Vad Lake — the March collapse — vGlubine.ru — the March collapse, April 2007… (archive)
  8. voshod-vad.ru — A WORTHY CONTRIBUTION TO THE DEVELOPMENT OF THE NIZHNY NOVGOROD REGION — Newspaper "VOSKHOD" — Voskhod, newspaper of the Vadskiy Municipal… (archive)
  9. voshod-vad.ru — THEY RESCUED A FREEZING SWAN — Newspaper "VOSKHOD" — Voskhod, newspaper of the Vadskiy Municipal District — They rescued a freezing swan, 19 March 2021… (archive)
  10. geraldika.ru — Coat of Arms of Vadskiy District — Geraldika.ru — Coat of Arms of Vadskiy District: State Heraldic Register No.… (archive)
  11. Nizhegorodskaya Pravda — The condition of Vad Lake is alarming ecologists (archive)
  12. NIA "Nizhny Novgorod" — The Ministry of Ecology of Nizhny Novgorod Region is preparing a list of water bodies requiring dredging (archive)
  13. vad.nobl.ru
  14. vad.nobl.ru