Guwahati: More than four years before the Dikhow River unleashed devastating floods in Assam’s Sivasagar district, the state’s water resources department had warned that indiscriminate sand and stone excavation along its banks could alter the river’s course and trigger widespread destruction.So far, 45 people have died in Sivasagar district alone out of a statewide toll of 80 recorded till Thursday.Following a field inspection in January 2022, the assistant executive engineer of the Nazira Water Resources Sub-Division wrote to then Nazira MLA Debabrata Saikia (Congress Legislature Party leader in the Assembly), reporting extensive excavation for sand and stone along the Dikhow riverbank near Bamunpukhuri Tea Estate.The inspection found deep excavation close to the river, widening of the channel and erosion on the opposite bank.“If the excavation of the bank continues, it may change the river’s configuration in the near future and may cause devastation to life and property in nearby areas and affect downstream stretches of the Dikhow river,” the official warned.That warning has acquired fresh significance after the July 19 floods, when the Dikhow burst its banks in parts of Sivasagar, wiping out villages such as Hiloni Nepali Khuti and leaving a trail of destruction.Hundreds of villages along both banks of the river—which originates in Nagaland’s Zunheboto district before joining the Brahmaputra at Dikhowmukh—were inundated. The floods killed several people, displaced lakhs of residents and destroyed homes, farmland, cattle and livelihoods.While exceptionally heavy rainfall over the Nagaland hills and the Upper Assam plains was the immediate trigger, the scale of the devastation has renewed questions over whether years of human intervention—from extensive sand and stone mining in the plains to illegal coal mining and deforestation in Nagaland’s upper catchments—may have intensified the impact.Experts have long cautioned that deforestation, unscientific hill cutting and mining can increase sediment loads, destabilise slopes and alter river channels, reducing a river’s capacity to carry floodwaters.Assam Chief Minister Himanta Biswa Sarma, however, urged against drawing premature conclusions. He said relief and rehabilitation must remain the government’s immediate priority and noted that Nagaland had also suffered extensive damage from floods and landslides.“Once things settle down, we will discuss with the Nagaland chief minister what the issue is, how it happened and what the solution is,” Sarma said.Saikia, who repeatedly raised concerns over mining along the Dikhow during his tenure as Nazira MLA, argued that satellite imagery comparing the river basin between 2010 and 2024 showed widespread alteration of the river corridor. He alleged that unchecked sand, stone and coal mining had transformed the riverbanks and contributed to the disaster.Nagaland’s own records point to extensive mining activity. A 2025 report by the state’s Soil and Water Conservation Department noted a “tremendous mushrooming” of rat-hole and opencast coal mines in the coal-bearing districts of Wokha, Mon, Mokokchung, Longleng—all bordering Assam—and Tuensang.Earlier, Nagaland Chief Minister Neiphiu Rio informed the state Assembly in 2024 that 45 coal mining licence holders were operating in these districts. He also acknowledged reports of illegal mining, though he said Nagaland’s unique land ownership system made such operations difficult to quantify.The Konyak Union, the apex body of the Konyak Naga tribe in Mon district, has strongly rejected allegations circulating on social media that the floods in Assam were caused by mining in Naginimora or by a Dikhu hydroelectric dam, pointing out that the project exists only as a proposal and has never been built.The union attributed the disaster to unprecedented rainfall on July 19 and 20, which triggered landslides and flash floods across Mon district, killing 11 people and displacing more than 650 families. It called for an expert-led, evidence-based investigation and urged public figures to avoid speculative claims unsupported by scientific evidence.The latest India State of Forest Report 2023 adds another dimension to the debate. It shows that Nagaland lost 51.89 sq km of forest cover between 2021 and 2023, with the steepest declines recorded in Mon, Zunheboto, Tuensang and Wokha. While the report does not attribute the losses to mining or any other specific activity, several of the affected districts overlap with the state’s coal-bearing belt identified by the soil and water conservation department.
