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.