Satellite imagery analysis and field assessments have revealed that the recurring flood crisis in Dimapur and Chumoukedima is a human-made disaster than a natural disaster.
Is the recurring flood crisis in Dimapur and Chumoukedima an act of nature, or a man-made disaster? Based on satellite imagery analysis and field assessments by engineers from the Water Resources Department, Nagaland, the answer is clear: our annual flooding is largely a human-made disaster caused by unchecked riverbed exploitation, encroachment, and improper project execution.
What should be a natural asset for our state has become an annual bane due to how we interact with our river systems and drainage networks.
1. Unregulated Riverbed Mining Changing River Behavior
Historical satellite imagery along the Chathe River and its tributary stretching from Peren district through Chumoukedima down to Dimapur shows a dangerous change in the river’s course and behaviour. Extensive, unregulated and illegal riverbed mining has stripped the river of its natural bed material. This human interference has forced the Chathe River to shift its path, particularly below the Patkai 4th Mile Bridge, causing severe bank erosion, destruction of property and land, and direct flood damage to downstream settlements.
2. Disruption of Water Flow and the Backflow Effect
Because the river's course has been artificially altered, the natural flow of water is severely disrupted. During heavy rains, the altered channel causes water velocity and water levels to spike rapidly.
When the river level rises high, it creates a backflow effect. Water from the main river pushes backward into all the major town drains and nallahs across Dimapur and Chumoukedima. Instead of rainwater draining away into the river, the river water surges back into our streets and homes, causing severe inundation.
3. Illegal Encroachment on Natural Drains
The problem inside our towns is made worse by widespread human interference. Most of the natural drainage paths and nallahs across Dimapur and Chumoukedima have been illegally encroached upon by buildings and structures. With natural drainage channels blocked and constricted, water has nowhere to flow, leaving town areas submerged after routine rain events.
4. Ignoring Nature’s Cycle and Flood Return Periods
As an engineer, we design structures based on standard flood return periods for 10-year, 25-year, 50-year or 100-year. However, satellite history shows that many constructions and barriers along the riverbed are built directly on land that the river naturally reclaims every 10 to 15 years. When we build walls, houses, and obstacles directly in the river’s natural path, nature will eventually take its own course and reclaim that space, breaking through artificial barriers.
5. Lack of Right Technical Expertise in Project Implementation
A major reason these flood problems repeat year after year is that water and river management projects are often implemented by other departments rather than specialised water resources engineers.
River training, anti-erosion works, and flood control require specific hydraulic expertise. When non-specialised agencies build these structures without proper hydrological design, the projects fail and public money is spent repeatedly without solving the root cause.
Conclusion
In conclusion, the recurring flood crisis in Dimapur and Chumoukedima is not an unsolved mystery but the problem is simply that we are not using the right engineering expertise for the solution to permanently fix this issue, we must:
• Stop illegal riverbed mining along the Chathe River to allow the river course to stabilise.
• Clear all illegal encroachments along urban drains and nallahs so water can flow freely.
• Respect natural floodways and stop building within high-risk flood zones.
• Entrust all flood control, river training, and drainage projects exclusively to the Water Resources department, ensuring that experienced engineers design and implement for long-term solutions.
Nature will always follow its own laws. By respecting river hydrology and putting specialized technical expertise at the forefront, Nagaland can finally protect its citizens from annual flood devastation.
Er. Ghunavi G Kinimi,
Sub Divisional Officer,
Water Resources Department,
Nagaland.