Ahmedabad: As the Gujarat government moves ahead with the ambitious ₹1.33 lakh crore Kalpasar Project and has sought environmental clearance for the mega undertaking, the alignment identified as the most suitable keeps the mouth of the Narmada River outside the proposed freshwater reservoir.

The decision stems from decades of technical, environmental and geological studies. During the project’s evolution, several alternatives were examined. Of these, three specific alignments were considered in detail, with the L3 alignment emerging as the preferred option. It connects Kardej village in Bhavnagar district with Paniyadra village in Bharuch district.

Unlike earlier proposals, the L3 alignment shifts the dyke nearly 15 km north of the Narmada estuary (where the tide meets the stream), ensuring that the river’s mouth remains open to the sea. This alignment has been selected to balance the project’s massive infrastructure ambitions with environmental protection and long-term operational safety.

Protecting the Narmada Estuary

According to project documents, the primary reason for keeping the Narmada River mouth outside the reservoir is to preserve the estuary’s marine ecosystem. The Narmada estuary serves as a crucial breeding ground for several marine fish species, and enclosing it within the reservoir could have adversely affected these habitats.

By leaving the river’s mouth open, the project aims to avoid ecological disruption and maintain the natural breeding and migration patterns of marine species. The design also includes a dedicated fish pass in the flood regulator structure to facilitate the movement of fish between freshwater and marine environments.

To further reduce environmental impacts, the project proposes a 5-metre-wide tree buffer along the reservoir side of the transport corridor to minimise disturbance caused by vehicle lights during nighttime.

Geological and Seismic Concerns

Technical studies also found the seabed near the Narmada mouth unsuitable for a massive dyke structure. Investigations revealed nearly 500-metre-thick layers of silty fine sand with extremely low bearing capacity, making the area vulnerable to structural instability.

The region is also intersected by multiple fault lines, raising concerns about seabed movement during earthquakes. Experts concluded that constructing the dyke near the estuary would expose the project to significant geotechnical and seismic risks.

The L3 alignment offers comparatively better soil conditions and avoids these high-risk zones, making it a safer engineering option.

Keeping Ports Operational

Another major factor behind the alignment shift was the need to protect existing port infrastructure. The northern alignment keeps the major ports of Dahej and Bhavnagar outside the dyke enclosure, ensuring that their operations and future expansion plans remain unaffected.

This was considered critical given the strategic importance of both ports to Gujarat’s industrial and maritime economy.

Managing Sediment and Water Quality

The project also seeks to prevent heavy sediment loads from entering the freshwater reservoir. Under the proposed design, Narmada waters will be diverted through the Bhadbhut Barrage and a barrage-cum-canal system, allowing sediments to be discharged into the sea rather than accumulating inside the reservoir.

Alignment also focuses solely on freshwater storage and excludes the earlier tidal power component. This eliminates the risk of saltwater leakage and helps ensure a reliable supply of freshwater.

Why L3 Was Chosen

Project assessments indicate that the L3 alignment was the only alternative among the 21 routes studied that was classified as having an overall beneficial environmental impact. Besides environmental advantages, it offers better geotechnical stability, improved groundwater quality, and the potential to bring nearly one lakh hectares of additional land under productive use.

The alignment will also support a major transport corridor featuring a 16-lane roadway and a four-track railway line, while reducing the travel distance between Bhavnagar and South Gujarat by nearly 180 km.

With environmental clearance now being sought, the L3 alignment has emerged as the preferred route for one of Gujarat’s most ambitious infrastructure projects, largely because it addresses ecological concerns while enhancing engineering safety and economic viability. DeshGujarat

The above two images show two alternatives