CHENNAI: While the whole world is talking about the success of Chandrayaan-3 and Aditya-L1 missions, the Indian Space Research Organisation (ISRO) is battling sea erosion at Sriharikota, which according to officials, has lost 100 metres of coastline in the last four years. As a mitigation measure, the Andhra Pradesh State Coastal Zone Management Authority has approved construction of groynes at India’s spaceport.
This was confirmed by ISRO officials to TNIE. In the recently held meeting in Vijayawada, the authority has reportedly given in-principle clearance for the groynes project, but precise details are not made public yet. However, sources told TNIE that the project would involve construction of five groynes, including two to three groynes measuring 100 to 150 m and two short groynes of 25-30 m in length on the northern tip of the island.
“We started getting worried from 2019-2020. The cyclonic storms washed-off two coastal roads and the third road also got damaged recently. We can’t risk losing any more land,” they said. After this, Satish Dhawan Space Centre (SDSC-Shar) had sought the help of Chennai-based National Centre for Coastal Research (NCCR) scientists early last year to conduct a shoreline study and suggest remedial measures for the sea erosion problem.
Accordingly, a detailed Integrated Management Plan was readied and submitted. “Now, the anti-erosion measures recommended by the NCCR got the approval of Andhra Pradesh State Coastal Zone Management Authority,” sources said.
A top official of NCCR told TNIE, “Our team has conducted shoreline studies along Sriharikota and further down north. Our analysis shows the island and nearby coastal areas are experiencing erosion due to both natural and anthropogenic activities. However, in recent days, low pressure systems and sea level changes have increased and hence more erosion is noticed at Sriharikota.”
Although initially soft solution like submersible dykes were contemplated, NCCR scientists, after conducting site-specific studies, have recommended building groynes and to prevent the erosion problem shifting to nearly coastal villages north of Sriharikota, beach nourishment was proposed. It is well-known that groynes will cause accretion on the south side and trigger erosion on the northern side.
Sources said ISRO officials are also wary of potential erosion threat to Sriharikota from the proposed Adani-Kattupalli port expansion in Chennai and the issue was notified to the Centre. As part of the port expansion, two new breakwaters of around total length of 9.35 km are proposed, out of which new northern breakwaters will be about 6.2 km and 1.3 km and new southern breakwater will be about 1.85 km.
G Sundarrajan, coordinator of environment advocacy group Poovulagin Nanbargal and member of Tamil Nadu Governing Council on Climate Change, told TNIE, “We can’t rule out the possibility of Adani-Kattupalli port expansion starving Sriharikota of sediment deposit. The lengthy breakwaters may block the long-distance sand transport and aggravate the erosion problem in Sriharikota, which is another important reason why this expansion should be resisted, besides several other environmental concerns.”