Discuss the doctrine of public trust and precautionary principle in Indian environmental jurisprudence, with reference to recent Supreme Court rulings.

The doctrine of public trust holds the State as trustee of resources like air, water, forests and riverbeds, while the precautionary principle requires that lack of scientific certainty not delay preventive action. Read into Article 21 alongside Articles 48A and 51A(g), both are today settled features of Indian environmental jurisprudence.

Doctrine of public trust

• Imported into Indian law in M.C. Mehta v. Kamal Nath (1997), where the Court cancelled a resort lease on the Beas riverbed and held that the State cannot abdicate its trusteeship by transferring ecologically sensitive resources to private use [1].
• Applies with special force to floodplains, which serve as flood buffers, groundwater recharge zones and biodiversity habitats — resources incapable of private appropriation.

Precautionary principle

• Articulated in Vellore Citizens' Welfare Forum v. Union of India (1996): authorities must anticipate, prevent and attack causes of degradation, and the burden of proof lies on the developer to show non-harm [2].
• Twinned with the polluter pays principle, it converts environmental restoration cost into legal liability, operationalised through compensation deposits.

Recent application: the Yamuna floodplain ruling (2026)

• Setting aside the NGT's 2017 order, the Supreme Court held that absolute liability requires a direct causal link between the activity and the damage, and ordered refund of the ₹5 crore deposited after the 2016 World Culture Festival [3].
• Significantly, the Court faulted the DDA's permission to host the event on an active floodplain as "avoidable" and contrary to both doctrines, and left its rehabilitation duties intact — shifting accountability toward the permitting authority [3].
• Appellate scrutiny of the NGT, a specialised tribunal under the NGT Act, 2010, shows judicial balancing of ecology with evidentiary rigour [4].

Both doctrines thus remain robust, but their promise depends on regulators refusing ecologically unsound permissions in the first place. Enforceable floodplain zoning, transparent expert assessment, and restoration projects like DDA's "Asita" [5] can convert judicial doctrine into ecological outcomes — advancing Article 48A and SDG 6 on healthy rivers.