Nainital Lake, a natural freshwater body, situated amidst the township of Nainital in Uttarakhand State of India, tectonic in origin, is kidney shaped or crescent shaped and has an outfall at the southeastern end. Nainital Lake, in the Nainital district called the Lake District of India, is one of the four Lakes of Kumaon hills; the other three lakes are the Sattal Lake, the Bhimtal Lake and the Naukuchiyatal Lake.
The nearest railhead on broad gauze line of North East Railways is at Kathgodam 35 km (22 mt) away from the lake and connects to Delhi, Dehradun and Howrah It is connected by National Highway No. to Delhi, Agra, Dehradun, Haridwar, Lucknow, Kanpur & Bareilly daily. The nearest airport is 70 km (43 mt) away.
Topography And Hydrology:
The lake is bounded by the high and steep Naina Peak on the North West side, by the Tiffin Top to the south west side and snow view peaks on the north. Coniferous forest trees cover these hill ranges. The annual rainfall in the basin area of the lake is reported to be 1294.5 mm (43.15 inches). Tropical monsoon climate with maximum temperature 24.6°C and minimum of 0.5°C are recorded. The water is reported to be alkaline in nature (ph value of 8.4-9.3). The lake receives flows from the surrounding catchment basin which comprises the hill slopes and springs.
The hydrologic studies related to water balance and sedimentation was done using radioisotopes for estimating/measuring the various components of the inflow and outflow into the lake. Studies indicated that the subsurface inflow and outflow were significant - ranging from 43 to 63% and 41 to 54%, respectively, of the total inflow and outflow, except in years of exceptionally heavy rainfall. The components of outflows were the surface outflow, the subsurface outflow through the springs on the downstream side and draft through wells for meeting the water supply of Nainital town and evaporation loss from the lake surface. The mean water retention time for the lake was computed as 1.16 years for the mean annual rainfall.
The Krol group of rocks, comprising slates, marls, sandstones, limestones and dolomites with a few small dykes intrusives, is the dominant geological formation of the lake’s surroundings. The lake is deduced to have been formed tectonically. Balia Nala, which is the main stream feeding the lake is along a fault line and the subsequent streams align parallel to major joints and faults. 26 major drains feed the lake including the 3 perennial drains. The lake catchment has highly folded and faulted rocks due to poly phase deformation. Landslides are a frequent occurrence in the hill slopes surrounding the lake, which are steep. The slopes are highly vulnerable to landslides and mass movement due to various geological and human factors. Several landslides have occurred in the past around the lake. Many settlements around the lake are located in landslide areas.
Flora And Fauna:
While the Nainital district where the lake is situated (in the middle Himalayan ranges up to 2,000 m (6,600 ft), a temperate zone), is rich in flora (typical temperate climate plants) and fauna, the details of the flora and fauna specific to the lake and its surroundings recorded are the following.
- Vegetation: The trees and bushes grown in the region (lake’s basin) with their botanical and common Indian names (in parenthesis) are reported to be: Quercus incana Oak (Banj); Aesculus indica (Pangar or Horse chestnuts); Juglans regia (Akhrot or walnut), Populous ciliata (Hill Pipal, a sacred tree); Fraxinus miscrantha (Ash tree or Angu); Platanus orientalis (Chinar); Rubus lasiocarpus (Hisalu); Rosa moschata (Kunj or Musk rose); Berberis asiatica (Kilmora); Cupressus torulosa (Surai or Himalayan cypress); Rhododendron arboreum (Buruns); Cedrus deodara (Deodar); Salix acmophylla (Weeping Willow); and Pinus (Pine). The Aquatic Macrophytic vegetation recorded are the Potamogeton pectinatus, Potamogeton crispus, Polygonum glabrum, Polygonum amphibium and Polygonum hydropiper (Water pepper). Several species of medicinal flora and horticulture plants have also been reported.
- Aqua Fauna: The fishes found in the lake are generally carps Mahseer, also hill trout and the mirror carp which breed several times during one spawning season during May to September. Two species of Mahaseer fish viz., Tor tor: The red finned mahseer and the Tor putitora: The yellow finned mahseer, a food fish which grows to varying sizes from 20 to 60 Cms (7.87 to 23.62 inches) are reported. The three species of Hill Trout found in the lake are the Schizothorax sinuatus, Schizothorax richardsoni and Schizothorax plagiostornus. The imported fish bred in the lake is Mirror carp or Cyprinus carpio. Gambusia affinis also called Mosquitofish have been introduced in the lake as a biocontrol measure to control Mosquito larvae.
- Fauna: Nine species of birds and nine species of animals have been recorded in the Nainital district.
There is the Nainital Boat Club that offers yachting facilities at the lake. The Annual Kingfisher Yachting Competition (Regatta) is held here in the third week of June. The Kumaon festival which brings out the local cultures and traditions is organized every year during the winter months of October and November, by the Tourism Department.