Interlinking involves the process of diverting surplus river water through a network of canals to relatively drier areas either within a state or among two or more states. In India, there is ambitious plan to link, Himalayan rivers, rivers flowing through northeast and peninsular rivers, to balance the deficit and excess water areas.

Intentions behind such an ambitious project are good, but there are concerns that it will lead to ecological imbalance.

Benefits of the project include:

• Equitable distribution on river water to reduce effect of drought and to help mitigate the impact of climate change.
• Reduce the incidence of flood by controlling surplus river water flow.
• Providing an infrastructure to promote inland navigation to reduce transport cost and to reduce pollution caused due to road transportation.

However the project has many ecological impacts such as:

• Submergence of large part of protected forest reserve, for example the submergence of large part of Panna Tiger reserve during Ken-Betwa linkage.
• Disruption of habitats for a variety of wild animals due to their relocation to other areas.
• Threat to natural movement of freshwater marine animals like fish, crocodiles etc.
• River interlinking will require clearance of large area of land which will result in deforestation.
• Reduction in quantity of natural flow of rivers especially peninsular rivers.
• Water logging, increased salinity and even water pollution due to inland waterway navigation.
• Connecting rivers coming through fragile topography may lead to increased seismic activity and increased frequency of floods.
• In certain cases, water has to b transported against gravity. It requires huge amount of power. It will create stress on economy as well as environment.
• Course of river changes after some time. For example, Teesta used to flow into Ganga, and now after an earthquake, it started to flow into Brahamputra. Linking them permanently will not be ecologically viable.

Conclusion

Though river interlinking project has certain envisioned benefits it is necessary to balance them with ecological devastation that might be caused due to the project. There is a need of comprehensive environment impact assessment so as to adopt the best alternative to minimize negative ecological impact so as to ensure sustainable development. Other than interlinking of rivers, Effective and efficient utilisation of existing water resources such as ground water, rain water harvesting, water preserving irrigation practices etc must be made priority.