Sustainable Operations: Dredging initiatives for a greener maritime sector

H.N. Aswath, development adviser (ports), Ministry of Ports, Shipping and Waterways (MoPSW)

The Indian maritime sector is witnessing rapid expansion, which, in turn, is boosting the need for dredging. Dredging has become an inevitable process for ports to sustain business, the economy and the environment. At a recent conference organised by Indian Infra­structure on “Dredging in India”, H.N. Aswath, development adviser (ports), Ministry of Ports, Shipping and Waterways (MoPSW), sha­red his views on the evolving dredging scenario in the country, emerging requirements, policy and regulatory initiatives, and the way forward for the sector. Excerpts…

The Indian maritime sector offers a plethora of opportunities for dredging. The yearly maintenance dredging requirement at major ports is approximately 86.06 million cu­bic metres (mcum). The dredging quantity carri­ed out at major ports is 84.20 mcum, 10 mcum at inland waterways and over 80 mcum at non-major ports. During 2017-18 and 2018-19, dredging (maintenance and capital) of ab­out 159.36 mcum was carried out in the country. Moreover, it is estimated that another 100 mcum capital dredging will be carried out in the coming years.

Traditionally, dredging projects have been plagued with issues of execution delays and co­st overruns. To overcome these challenges, the MoPSW issued Dredging Guidelines in June 2021, laying down the standard operating procedures for undertaking capital and maintenance dredging projects at major ports. The aim of these guidelines is to minimise downtime and economic and environmental loss, av­oid conflict and achieve greater sustainability in dredging operations.

These guidelines are based on the scientific mode of “working dredging rate” for minimising associated costs and include detailed technical investigation for dredging projects. Survey and geotechnical investigation are two crucial aspects of a dredging project. Detailed investigations are prerequisites for equipment planning, rate determination and avoiding conflicts between the contractor and the port authority. Besides, these guidelines highlight the importance of reusing dredged material.

Dredging projects are expected to generate economic growth by enhancing export-import trade.

In fact, recycling and reusing dredging material has been a key focus area for the MoPSW. The utilisation of these materials resu­lts in saving a significant amount of resour­ces, thereby contributing to environmental conservation.

The 12 major ports under the administrative control of the MoPSW undertake dredging activity for the removal of dredged material to maintain navigable depth for vessel movement. The material comprises a mixture of silt, clay, sand, gravel and other impurities. Typica­lly, this material is either disposed of to the deep sea or used for reclamation purposes, if suitable.

The MoPSW guidelines call for major ports and the Inland Waterways Authority of India to incorporate suitable provisions in dredging contracts for promoting the reuse/recycling of generated dredged material. This also rationalises the cost of dredging through the monetisation of the dredged material, resulting in the creation of “wa­ste to wealth”. Moreover, the utilisation of the­­se materials contributes to resource sustainability, thereby aiding environmental conservation efforts through the recycling of waste and the conservation of fresh resources.

Several major ports are already utilising dredged soil for beneficial purposes. For instan­ce, Cochin Port is incorporating it into construction activities (approximately 30 to 40 mcum). Visakhapatnam Port and Jawaharlal Nehru Port Authority use dredged soil for beach nourishment  while the V.O. Chidambaranar Port Autho­rity utilises it for reclamation purposes. Paradip Port is also utilising dredged soil for land reclamation for Numligarh Refinery Limited and at a storage terminal complex at Paradip.

Ministry’s focus areas and priorities

The MoPSW formulated the Maritime Vision for 2030 with the objective of propelling India to the forefront of the global maritime sector. It is aimed at developing a roadmap for undertaking projects, including dredging initiatives, to create infrastructure to accommodate larger vessels. The vision also envisages the development of major ports as transshipment hubs wherever possible.

In the coming years, the major ports sector will take further measures to deepen ports, allowing them to receive more container parcel vessels. This includes having at least one berth with a draft of 16-16.2 metres and a maximum berth over 14 metres of draft for bulk (panamax compliant). Additionally, some major ports are planning to increase the draft to at least 18 metres at one of their berths. To this end, the Paradip Port, Kamarajar Port, Jawaharlal Neh­ru Port and Cochin Port have already prepared proposals. Furthermore, other ports, excluding the V. O. Chidambaranar Port and Kolkata Port, have been preparing technical studies for taking up draft enhancement projects.

Meanwhile, the MoPSW has developed an online dredging monitoring system to streamline monitoring. This system has been de­ve­lop­ed in collaboration with the National Tech­no­lo­gy Centre for Ports, Waterways and Coasts and IIT Madras. It monitors the output of the dred­ger on a daily, weekly and monthly basis. It also monitors the dredger’s performance and its downtime, and displays data related to loading positions, production docks near real-time vessel positions and dumping grounds. The system utilises internet mapping and web services technology to provide dynamic data and monitors dredging data online.

Going forward, increasing the dredging capacity across the country will remain a key fo­cus area of the ministry. India has a huge po­tential for this, with approximately 200 mcum of capacity for maintenance dredging.

Another important aspect is the monitoring of decarbonisation. The global call for the de­car­bonisation of all vehicles and vessels re­quires the shipping industry to adopt environment-friendly fuels such as methanol and liquified natural gas. According to international shi­p­ping statistics, 700 million metric tonnes of car­bon dioxide was emitted into the atmosphe­re from ship operations in 2021. Thus, dred­gers equipped with increased hopper capacities of 12,000 or more, along with fuel-efficient engines, can bring about a drastic re­duction in dredging costs, and in turn, logistics costs, thereby boosting the economy.

Environment suitability and the reuse of dredged materials should be a high priority for any dredging project. Capital dredging projects require extensive data collection, soil characteristics, and dumping yard identification to ensure sustainability.

Dredging projects are expected to generate economic growth by enhancing export-import trade. However, we must ensure that the eco­system is preserved, including the marine flora and fauna, allowing them to remain undistur­bed. The reuse of dredged soil, which is one of the methods for ecosystem perseveration, should be taken up extensively.

The country has also been facing a major challenge in establishing a hydrogen hubs, whi­ch are the fuel source for future generation ve­ssels. Dredgers with improved designs and eco-friendly fuels would play a big role in achie­ving decarbonisation.

The aim of the guidelines is to minimise downtime and economic and environmental loss, avoid conflicts, and achieve greater sustainability in dredging operations.