Rising Freshwater Threatens Lonar Meteor Crater Ecosystem

India’s only basaltic meteor impact crater, Lonar Lake in Maharashtra, is facing an unprecedented environmental crisis as rising freshwater inflows threaten to irreversibly alter its unique ecology and heritage. Formed around 50,000 years ago, the lake has long been studied as a rare terrestrial analogue for Martian geology, owing to its extreme chemistry and isolated ecosystem.

Unique Geological And Ecological Significance

Located in Buldhana district, Lonar Lake is a closed-basin crater formed by a meteorite impact on basaltic rock. Designated as a Ramsar wetland, it historically maintained high salinity and an alkaline pH of around 11.5, conditions hostile to fish but ideal for specialised microbes. This extreme environment made the lake globally significant for planetary and microbial research.

Unprecedented Water Influx And Visible Damage

Over the past year, water levels have risen sharply, submerging nine of the 15 ancient temples along the shoreline, including the revered Kamalja Devi temple. The crisis prompted the Nagpur bench of the Bombay High Court to take suo motu cognisance, seeking explanations for the drastic changes to this protected natural monument.

Human Intervention Behind The Crisis

According to hydrogeologist Ashok Tejankar of Dr. Babasaheb Ambedkar Marathwada University, the lake level has risen by nearly 20 feet. While increased rainfall played a role, the primary cause is the proliferation of deep borewells in the surrounding catchment. These wells have pierced previously impermeable basalt layers, activating underground aquifers that now funnel freshwater into the crater through newly energised springs.

Important Facts for Exams

• Lonar Lake is India’s only known basaltic meteor impact crater.
• It is a Ramsar-designated wetland located in Maharashtra.
• The lake’s pH has dropped from about 11.5 to nearly 8.5.
• Closed-basin lakes have no natural surface outflow.

Ecological, Social, And Governance Challenges

The dilution of alkaline waters threatens the lake’s endemic microorganisms and has already allowed fish to survive for the first time on record. Ironically, Lonar town itself faces water scarcity despite the overflowing crater. Experts have proposed diverting and treating spring water for local use to stabilise the lake. However, conservation efforts are hindered by land-use conflicts, stalled acquisition for research, and regulatory constraints under the Wildlife Protection Act, leaving the future of this globally significant site uncertain.