Bhimtal Lake: A Jewel in Uttarakhand's Lake District

Bhimtal Lake, nestled in the town of Bhimtal in the Indian state of Uttarakhand, is a prominent landmark and a vital resource for the region. Often referred to as the largest lake in the Kumaon region, also known as the "Lake district of India," Bhimtal Lake is a gravity masonry marvel that attracts tourists and supports local ecosystems. The lake and the town derive their name from Bhima, one of the Pandava brothers from the epic Mahabharata, adding a layer of historical and mythological significance to the area.

History and Formation

Geological analysis suggests that Bhimtal Lake was formed due to the shifting of the Earth's crust, which resulted in faults that blocked overland flows, leading to the creation of The Lake. This natural damming process has created a unique and picturesque landscape that continues to evolve.

Geography and Hydrology

Located at coordinates 29°20'35"N and 79°33'33"E, Bhimtal Lake sits at an elevation of approximately 1,375 meters (4,511 ft.) above sea level. The lake boasts a catchment area of about 17.12 square kilometres (6.61 sq. mi) and a surface area of roughly 47.8 hectares (118 acres). With a length of about 1701 meters, a width of approximately 451 meters, and a depth of around 18 meters, Bhimtal Lake has a gross storage capacity of about 4.63 million cubic meters (164 X 10^6 cu ft.) and a live storage capacity of about 3.54 X 10^6 m3 (125 X 10^6 cu ft.)

The lake's water source is primarily subsurface, with a surface inflow of only 1.756 X 10^6 m3 (62.0 X 10^6 cu ft.) Characterized by its "C" shape, the lake is known for its depth and generally clear water. However, during certain months, the water acquires a brown coloration due to the presence of animalcule, a phenomenon that is woven into local folklore.

Classified as manomictic, Bhimtal Lake experiences stratification from March to November, with one inner circulation. The stored water is released through an outlet that feeds into the Gola River, supplementing the flows of the Bhabar canals. The water surface area of the lake fluctuates with the release of water from the reservoir.

The lake's banks are steep, with shingle at lower elevations and bushes and grass at higher elevations. The western side features forested areas adorned with cottages, while a 17th-century temple built by Raja Baj Bahadur Chand of the Kumaon Kingdom stands on the banks of the dam.

A peripheral road around the lake offers views of the fish life and terraced fields on the opposite side. A small shopping center is located on the southern shore, and a sanitarium, established in 1902 to house prisoners of the Boer War, is situated on the northern shore at a height of about 1,525 meters (5,003 ft).

Climate

The Bhimtal Lake basin experiences a range of tropical to sub-tropical weather conditions. The region receives high precipitation, primarily during the monsoon season.

Flora and Fauna

The hills surrounding Bhimtal Lake are covered with dense forests, including chir pine, ban oak, and mixed deciduous forests.

Bhimtal Lake is home to various fish species, and a fish farm has been established to utilize this resource. Mahseer and Tor putitora are commonly caught in the lake. Other fish species include snow trout, catla, rohu, silver carp, grass carp, common carp (cyprinus carpio), and major carps like labeo rohita, cirrhinus mrigala, and catla catla. Fishing is permitted with the approval of the Deputy Commissioner.

The surrounding area is also a habitat for wildlife, including barking deer, Kalij pheasants, Koklass pheasants, white-capped laughing thrush, migratory ducks, and geese.

Utilization and Tourism

Bhimtal Lake holds significant economic and social value. Aquaculture is thriving due to the diverse fish species in the lake. The picturesque island in the center of the lake, accessible by rowing boats, features recreation facilities and an aquarium, drawing numerous tourists. The lake also serves as a source of drinking water.

Development

A dam was constructed on Bhimtal Lake in 1883 during the British Raj, following the Anglo-Nepal War (1814–1816). Located in Seismic Zone IV, the masonry structure is approximately 150 meters (500 ft.) long and 14.8 meters (48.5 ft.) high. The base of the dam is about 11 meters (36 ft.) wide, tapering to a top width of 3.0 meters (10 ft.) The dam is estimated to have a flood discharge capacity of about 1,600 cu ft./s via a chute spillway with 12 gates.

Ecological Challenges

Bhimtal Lake faces ecological challenges such as retrogressive changes in water quality due to sewage disposal, sediment inflow, and waste disposal by tourists. These activities have led to harmful levels of dissolved oxygen. The lake is in a mesotrophic state due to sewage disposal from residential areas and is approaching eutrophication due to high nitrate levels. Shale and debris from residential complexes built on the banks of the tributary stream have further deteriorated the lake's quality. The accumulation of injurious matter in the lakebed has resulted in high fish mortality rates and poor drinking water quality.

Restoration Efforts

To address these challenges, several restoration steps have been planned. A sewer line is proposed around the lake's periphery to trap sewage from residential areas. Regular dredging is essential to remove sediments caused by building activity on the banks. A treatment plant is also planned for waste water treatment.

Visiting Information

The nearest rail-head to Bhimtal Lake is Kathgodam, located about 20 kilometers (12 mi) away. The lake is approximately 22.5 kilometers (14.0 mi) from Nainital.

Bhimtal Lake remains a significant ecological and Tourist Destination in Uttarakhand, requiring continued efforts to preserve its natural beauty and ecological integrity.