The Dikhow River triggered one of the worst flood disasters in Sivasagar district in July 2026, causing heavy loss of lives and property. The disaster has renewed concerns over upstream environmental degradation, river pollution and disaster preparedness.

Key Highlights

• The Dikhow River rose from the warning level to its highest recorded flood level within a few hours, leaving little time for evacuation and resulting in widespread devastation across Sivasagar district.
• Experts believe that extreme rainfall alone may not explain the sudden flood surge. Large-scale deforestation, coal mining, stone quarrying, hill cutting and shifting (Jhum) cultivation in the river’s upper catchment in Nagaland may have intensified runoff and erosion.
• Researchers have suggested that a landslide-induced temporary blockage, followed by its sudden collapse, may have created a flash-flood-like event, similar in behaviour to a Glacial Lake Outburst Flood, although no glacial lake was involved.
• The North Eastern Regional Disaster Management and Research Centre observed that fragile Disang rock formations, slope instability, heavy rainfall and changing land use collectively increased landslide risks in the Naga Schuppen Belt.
• The Pollution Control Board, Assam had earlier identified acidic water, pollution and shrinking river channels in the Dikhow, indicating long-term ecological stress.

About the Dikhow River

• The river Dikhow is considered as one of the important south bank tributary of
• the river Brahmaputra. 
• The river originates in Zunheboto district of Nagaland and enters into the Assam plain through Naginimara of Sivsagar district of Assam. 
• It mingles with the river Brahmaputra at Dikhowmukh on its southern bank within the district. 
• The river basin is surrounded by the Brahmaputra river in the north, Buridihing basin in the east, Jhanji basin in the west and the Naga hill in the south. 
• The total length of the river is 236 km and the catchment area of the basin is 4372 sq.km. and in Assam the length of the river stretch is 98.5 km.
• The river leaves abandoned channels at different places of Assam plain mostly in the form of Ox-bow Lake. 
  • Among these, Mori-Dikhow is the longest one with a length of 20 km extending from Naginimara to near Hatipati Tea garden. 
• In Assam plain, Dikhow River joins with two small streams Borjan stream and Owgurijan stream on its right bank. 
• A tributary river named as Dorika river, joins finally with the river Dikhow on the right hand side near Saraguri. 

Why is Disaster Management Important?

• The floods highlight the need for interstate river basin management between Assam and Nagaland.
• They demonstrate how environmental degradation in upstream catchments can significantly worsen downstream flood disasters.
• They reinforce the importance of scientific land-use planning, slope stabilisation, catchment conservation, real-time flood forecasting and early warning systems under the Disaster Management Act, 2005 and the National Disaster Management Authority framework.

Exam Hook – Prelims Question

Q. Consider the following statements regarding the Dikhow River:

1. It originates in Nagaland and is a tributary of the Brahmaputra River.
2. It joins the Brahmaputra at Dikhowmukh in Assam.
3. It is known for forming several oxbow lakes in the Assam plains.

Which of the statements given above is/are correct?

(a) 1 only
(b) 1 and 2 only
(c) 1, 2 and 3
(d) 2 and 3 only

Answer: (c) 1, 2 and 3

One-line Wrap

The Dikhow River disaster shows that protecting upstream ecosystems is essential for reducing downstream flood risks and building climate-resilient river basin management.