Water being a State subject, how can the Centre constitutionally drive national-level water research and surveillance? Discuss with reference to inter-ministerial mechanisms.

Water — supplies, irrigation, canals, drainage — falls under Entry 17, List II, yet river basins, climate risk and satellite data are inherently trans-State. The Centre's role therefore rests not on encroachment but on distinct constitutional entry points reinforced by inter-ministerial coordination.

Constitutional entry points

• Entry 56, List I empowers the Union to regulate and develop inter-State rivers and river valleys in the public interest [1].
• Article 262 authorises Parliament to legislate on inter-State water disputes — operationalised through the Inter-State River Water Disputes Act, 1956 and River Boards Act, 1956 [2].
• Research and remote sensing are not "water" but science and technology; space is a Union subject under the residuary/Union heads, and Entry 20, List III (economic and social planning) permits joint action [1].
• Article 253 lets the Union legislate to honour climate and SDG-6 commitments [1].

Statutory surveillance mandate

• The Dam Safety Act, 2021 creates the National Dam Safety Authority and mandates surveillance of specified dams — a direct central hook for satellite-based reservoir monitoring [3].

Inter-ministerial mechanisms

• The Ministry of Jal Shakti (2019 merger) provides a single water window; the DoWR–ISRO MoU (June 2026) identifies 24 priority areas — reservoir and water-spread assessment, river-flow analysis, satellite water-quality monitoring, macroplastic mapping and flood-inundation mapping [4][5].
• MAHA on Water, backed by an ANRF–Jal Shakti ₹200-crore mission, channels research funding to startups and academia [6].
• India-WRIS (CWC–ISRO) and the National Hydrology Project supply the operational data backbone [7].

Limitations

• Central data cannot substitute State implementation; excessive centralisation risks friction, and States remain custodians of usage and delivery.

Thus the Centre acts as a knowledge and standards provider, not a regulator of State water use — a cooperative-federal division that the ISRO–Jal Shakti partnership exemplifies. Institutionalising data-sharing with State agencies under the National Water Mission would convert satellite intelligence into on-ground water security, advancing both SDG-6 and the federal spirit of the Constitution.