built in 1883 when Kumaon region was under the British Raj following the Anglo-Nepal War (1814–16). Nainital had then been established as their summer capital. The town and the lake are named after Bhima, one of the Pandavas of the epic story of Mahabharata who is said to have visited the place. On the banks of the dam there is an old temple which was built by Raja Baj Bahadur Chand of Kumaon Kingdom during the 17th century. Features The "C" shaped lake, which is the largest in the Kumaon region, impounded by the masonry dam has an area of . It has a gross storage capacity of with a live storage of . The surface inflow into the reservoir is only and the balance storage is contributed by subsurface sources. The reservoir has been classified as manomictic with stratification extending over a period from March to November, with one "inner circulation." There is inflow of sediment from the catchment due to intense building activity on the banks. This has necessitated dredging of the lake regularly. Lake water which is generally clear, gets a brown coloration during some months as a result of infused animalcule. According to a local myth the coloration disappears once the lake claims a victim. The stored water is released through an outlet leading to the Gola River which is utilized to supplement the flows of the Bhabar canals. As the reservoir water is released, the water surface area of the lake gets reduced, when the water getting released, by with consequent reduction of the size of the reservoir to half its original spread. Water quality of the lake is in a "retrogressive ecological change" on account of a) sewage disposal, sediment inflow, and tourists' pressure causing waste disposal. This has resulted in dissolved oxygen level recorded at harmful levels to both domestic consumption and pisciculture. Nitrate level is also stated to be high at 350 mg per liter which is considered a "pre-eutrophication stage". In the bed of the lake there are deposits of injurious matter and as a result fish mortality rate is high and the quality of drinking water has also suffered. As the lake water is polluted with organic matter, it is in a mesotrophic state due to disposal of sewage directly into the lake from the residential complex built around the periphery of the lake. It has now been planned to