Nainital Lake
Nainital, also known as Naini Lake, is a natural freshwater body, situated amidst the township of Nainital in Kumaon, Uttarakhand, India. It is tectonic in origin and is kidney shaped or crescent shaped and has an outfall at the southeastern end. Nainital, along with other lakes of Kumaon, is integral to tourism and recreation in Kumaon. The lake is also an integral part of Kumaoni folklore. Nainital Lake in the Nainital district, often called the Lake District of India, is one of the four important lakes of Kumaon; the other three are Sattal Lake, Bhimtal Lake and Naukuchiyatal  Lake. History. Historical records confirm that in 1839, Mr. P. Barron, who is supposed to be the first one who visited Nainital . He was an English business man in sugar trade, on an expedition accidentally coming across the lake at Nainital was so captivated that he decided to build a European Colony on shores of the lake. The news magazine, the "Englishman Calcutta", reported in 1841 discovery of this lake near Almora. It is believed that two Indian sages visited there, wandering, it is a belief of people that they blessed the lake with divine power, one can acquire divinement  by taking bathe in it, and the same as in the Mansarovar lake. 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 . 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. Geology. 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 (pictured) 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 , 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: a) "Quercus incana" Oak (Banj); b) "Aesculus indica" (Pangar or Horse chestnuts); c) "Juglans regia" (Akhrot or walnut), d) "Populus ciliata" (Hill Pipal, a sacred tree); e) "Fraxinus micrantha" (Ash tree or Angu); f) "Platanus orientalis" (Chinar); g) "Rubus lasiocarpus" (Hisalu); h) "Rosa moschata" (Kunj or Musk rose); i) "Berberis asiatica" (Kilmora);j) "Cupressus  torulosa" (Surai or Himalayan cypress); k) "Rhododendron arboreum" (Buruns); "Cedrus deodara" (Deodar); l) "Salix acmophylla" (Weeping Willow); and m) "Pinus" (Pine). The Aquatic Macrophytic vegetation recorded are the a) "Potamogeton pectinatus", 2) "Potamogeton crispus", 3) "Polygonum glabrum", 4) "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: species of mahseer, hill trout, and the mirror carp which breed several times during one spawning season during May to September. Two species of mahaseer fish are present: "Tor tor", the red -finned mahseer, and "Tor putitora" the yellow-finned mahseer, a food fish which grows to varying sizes from are reported. The three species of hill trout found in the lake are "Schizothorax sinuatus", "S. richardsoni" and "S. plagiostornus". The imported fish bred in the lake is mirror carp, a variety of the common carp "Cyprinus carpio". The mosquitofish "Gambusia affinis" has been introduced in the lake for the biocontrol of mosquito larvae. Fauna. Nine species of birds and nine species of animals have been recorded in the Nainital district. Water quality. A scientific study indicates that the open drains feeding  the lake introduce toxic substances from the catchment of the lake, particularly heavy metals which get adsorbed onto the suspended sediments, which in turn settle down in the bottom of the lake. A study of the risk assessment code has revealed that 4–13% of manganese, 4–8% of copper, 17–24% of nickel, 3–5% of chromium, 13–26% of lead, 14–23% of cadmium and 2–3% of zinc exist in exchangeable fraction which puts the lake under the low to medium risk category and infers that it could enter into food chain and also cause deleterious effects to aquatic life. This study provides the  basic database to formulate guidelines for the dredging operations and/or restoration programmes in the lake. The water quality studies carried out by the National Institute of Hydrology during 1999–2001 on physico-chemical parameters (pH, temperature profile, Secchi's transparency, dissolved oxygen, BOD, COD and nutrients), biological profile (density of population, biomass and species diversity of phyto, zooplankton and macrobenthos) and bacteriological characteristics have led to the conclusion that long-term limnological changes have occurred in the lake. Excess of nutrients inflow have contributed to the eutrophic conditions and the internal recycling of nutrients from sediments during water circulation has resulted  in luxurious growth of phytoplankton. The lake is thus anoxic and has reduced hypolimnion, winter circulation, large phytoplankton and relatively lower animal population. Threats to the lake. The problems facing the lake which were also listed in the plea in a Public Interest Litigation (PIL) before the Supreme Court of India in 1995 seeking court directive for redress measures could be summarised as below: Lake restoration. The National Institute of Hydrology (NIH) of Roorkee who prepared a plan for the restoration of the lake, at an estimated cost of Rs 50 crore (about US$10 million), sponsored by the Ministry  of Environment and Forests, Government of India, are also now guiding the restoration measures. The Conservation and Management Plan evolved by NIH is not only lake centric but also proposes to tackle the immediate periphery of the lake which contributes an adverse impact on the lake. The "Nainital Jheel Parikshetra Vishesh Kshetra Vikas Pradhikaran", the Lake Development Authority notified under U.P. Special Area Development Act 1986 is a Special Purpose Vehicle (SPV) set up for implementing the restoration works. The restoration works that have been implemented or are in different stages of implementation are the following: The Honourable Supreme Court  of India in its judgment of 1995, in response to the Public Interest Litigation, gave the following recommendations which have also been addressed in the restoration measures mentioned above. (i)Sewage water has to be prevented at any cost from entering the lake; (ii) So far as the drains which ultimately fall in the lake are concerned, it has to be seen that building materials are not allowed to be heaped on the drains to prevent siltation of the lake;(iii) Care has been taken to see that horse dung does not reach the lake. If for this purpose the horse stand  has to be shifted somewhere, the same would be done. The authorities would examine whether trotting of horses around the lake is also required to be prevented;(iv) Multi-storeyed group housing and commercial complexes have to be banned in the town area of Naini Tal. Building of small residential houses on flat areas could, however, be permitted;(v) The offence of illegal felling of trees is required to be made cognizable.(vi) Vehicular traffic on the Mall has to be reduced. Heavy vehicles may not be permitted to ply on Mall;(vii) The fragile nature of Ballia Ravine has to be taken care  of. The cracks in the revetment of Ballia Nullah have to be repaired urgently. In the "India Today" magazine, Prasanta Rajan, a journalist, in a preamble to the particular interest shown by the Lady District Magistrate of Nainital in restoration works of the lake has very vividly described the lake in these words: Look for the lake through the colonial windows of Pant House, a vintage English bungalow on the hilltop, now submerged in wintry night, solitary with a kind of Wuthering Heights mystery. Down below, the lake is a laminated stillness, protected by seven never-sleeping hills. In the  dead darkness of Kumaon, this magnificence is a distant, partially lit vision, less than real, as the hills of frozen memories make the lake a footnote in water. Other attractions. The Nainital Yacht Club, housed in the Boat House Club, offers yachting facilities at the lake, where a fleet of Half Raters, designed by Linton Hope, sails. 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. Nainital