The Bhoj wetland is situated in the heart of Bhopal district in Madhya Pradesh.
The wetland consists of two man-made lakes–the upper lake and the lower lake.
The upper lake, the oldest among large man-made lakes in central India, was created by king Bhoj in the 11th century by constructing an earthen dam across the Kolans river.
The Kolans was formerly a tributary of the Halali River; with the creation of the Bhojtal and a diversion channel, the upper reach of the Kolans River and the Bhojtal now drain into the Kaliasot River.
Bhadbhada dam was constructed in 1965 at the southeast corner of the Bhojtal; it now controls the outflow to the Kaliasot river.
The Lower Lake was created in 1794 by Nawab Chhote Khan, Minister of Nawab Hayath Mohammad Khan, to beautify the city.
It is also contained behind an earthen dam, and drains into the Halali River via the lower reach of the Kolans River, presently known as the Patra Drain.
Both the Kaliasot and Halali Rivers are tributaries of the Betwa River.
The lakes are home to a diverse flora and fauna, including many waterbirds.
The upper lake in Bhopal is an important wetland which is home to more than 700 species of diverse flora like zooplankton, phytoplankton, etc.
The wetland is also an important site of avian fauna with more than 150 species of both migratory and resident birds.
About 2,500 migratory birds across the world visit the wetland that serves as a breeding and nesting habitat for them.
The lakes are very rich in biodiversity, particularly for macrophytes, phytoplankton, zooplankton, both natural and cultured fish species, both resident and migratory birds, insects, reptiles and amphibians.
This rich biodiversity of the wetland has, however, been affected adversely in the last few years due to various anthropogenic pressures and natural calamities, irregular rainfall during the last decade being one of them.
The upper lake is the principal source of drinking water (40 percent) for the city of Bhopal; the lower lake meets out the requirement of raw water and enhances the beauty of the city.
These lakes are ideal spots for watersports like kayaking, canoeing, parasailing and water skiing and attract tourists in hordes.
The upper lake is a source of livelihood–both direct and indirect–for many communities including fishermen, boat owners and local vendors.
Problems the lakes face
The last six decades have seen rapid urbanisation near the Bhoj wetland resulting in various environmental problems.
The water quality is getting deteriorated from the sewage inflow from urban areas, agricultural waste from rural areas and industrial effluents, apart from the flourishing growth of invasive aquatic plants, depletion of biodiversity and other anthropogenic activities.
Efforts:
The National Green Tribunal (NGT ordered the MP state govt to stop the operation of cruise vessels as well as other motor-propelled boats in the Bhoj wetland on account of the drastic damage being done to water bodies.
