The Role of Dredging in Preventing Floods and Tidal Surges in Kerala’s Coastal Regions

Introduction

Kerala, located along India’s southwestern coast, is known for its beautiful backwaters, bustling harbors, and vibrant fishing communities. However, the state’s coastal regions are often vulnerable to challenges like tidal surges, flooding, and navigational hazards due to natural factors such as sandbars and shoaling. These issues can lead to severe economic and environmental consequences for local communities. Dredging, an essential process to maintain safe and navigable waterways, plays a critical role in addressing these challenges and preventing floods and tidal surges.

Understanding Dredging and Its Purpose

Dredging is the process of excavating and removing sediment or debris from the bottom of water bodies, such as rivers, lakes, and harbors. In coastal regions, dredging helps maintain the depth of navigation channels, ensuring that ships, boats, and fishing vessels can safely pass through.

The primary purpose of dredging is to remove accumulated sediment, such as sand, silt, and mud, which can obstruct water flow and reduce the depth of waterways. In areas where shoaling occurs—where sediment builds up over time—dredging is necessary to restore the depth of the water to its authorized level. This process not only ensures safe navigation but also mitigates the risk of flooding and tidal surges by improving water flow and reducing the accumulation of water in obstructed areas.

The Impact of Sandbars and Shoaling in Kerala’s Harbours

In Kerala’s coastal regions, the buildup of sandbars and shoaling has become a significant concern. Sandbars are formed when sediment is deposited in shallow areas of rivers or harbors, blocking the flow of water and causing reduced depth. These sandbars can obstruct the smooth passage of boats and ships, and more critically, they contribute to flooding and tidal surges.

For instance, Muthalapozhy, a major fishing harbor located where the Vamanapuram river meets the Arabian Sea, has faced such challenges. The harbor’s inlet has been severely affected by a submerged sandbar, which has drastically reduced the water depth and caused dangerous currents. Fishermen in the area have been unable to safely navigate through the harbor mouth, leading to numerous accidents. Strong conflicting currents have drawn boats into dangerous areas, exacerbating the risk of capsizing and accidents.

Case Study: Muthalapozhy Harbour

Muthalapozhy is one of Kerala’s prominent fish landing centers, providing essential anchorage for hundreds of traditional fishing boats. The harbor serves as a vital source of livelihood for local fisherfolk families, supporting the region’s economy. However, the harbor has faced significant challenges due to the accumulation of sandbars and shoaling at its mouth.

Fishers have expressed growing concern over the hazardous conditions in the harbor, where the reduced depth and conflicting currents have led to a rising number of accidents. Tragically, over the past year, at least 14 fishermen have lost their lives, and many others have sustained serious injuries in accidents related to the harbor’s dangerous conditions. In addition to the loss of life, fishing boats and valuable gear have been swept away, further straining the community.

In response to these challenges, the government has undertaken significant measures to expedite dredging at Muthalapozhy. The state government has increased the daily dredging hours from 10 to 20 hours to address the sandbar issue quickly and restore safe navigation. The Kerala Maritime Board’s Chandragiri dredger, along with six additional Hitachi long boom dredgers, has been mobilized to speed up the dredging process and prevent further accidents.

Dredging Solutions to Tidal Surges and Flooding

The ongoing dredging efforts at Muthalapozhy aim to prevent the recurrence of flooding and tidal surges in the region. By removing the sediment buildup from the harbor mouth, dredging helps restore the flow of water, preventing blockages that could otherwise exacerbate flooding during monsoon seasons.

One of the critical aspects of dredging is ensuring the removal of excess sandbars that block water channels. When these sediment deposits are cleared, the water flow is improved, reducing the chances of water accumulation, which can lead to flooding. The expedited dredging at Muthalapozhy is expected to restore the harbor’s depth, ensuring safe access for fishing boats and mitigating the risks posed by high tides and strong currents.

Additionally, the government has planned to open sandbars formed off other coastal localities such as Vakkom, Chirayankeezhu, Kadakkavoor, Anchuthengu, Azhoor, and Kadinamkulam. These sandbars have also contributed to tidal surges and flooding in the surrounding areas. By clearing these sandbars, the authorities hope to reduce flooding and safeguard local communities.

Environmental and Economic Benefits of Dredging

The dredging process has both environmental and economic benefits, particularly for coastal communities like those at Muthalapozhy.

Environmental Benefits:

Dredging helps maintain healthy marine ecosystems by preventing sediment accumulation that could damage fish habitats. By ensuring that water channels remain navigable, dredging reduces the risk of water stagnation, which can lead to the growth of harmful algal blooms and other water quality issues. Additionally, by removing sediment from strategic locations, dredging can help maintain coastal biodiversity, including seagrass beds, which are vital for maintaining fish populations.

Economic Benefits:

For fishing communities, dredging directly impacts their ability to access safe harbors. When harbors are navigable, fishing boats can enter and exit without the risk of running aground or being caught in strong currents. This, in turn, enhances the local fishing economy, supporting thousands of fishermen who rely on safe and efficient docking facilities. Furthermore, dredging prevents significant losses of fishing gear, boats, and infrastructure, which are costly to replace.

Challenges in Implementing Dredging Projects

While dredging offers significant benefits, it is not without its challenges. The process of dredging requires substantial financial investment and technical expertise, as well as careful planning to minimize environmental impacts. Local governments must balance the immediate need for dredging with long-term sustainability goals, ensuring that dredging operations do not negatively affect ecosystems or contribute to the erosion of coastlines.

Additionally, the dredging process can face logistical challenges, such as poor weather conditions and limited resources. There are also concerns about the disposal of dredged material and how to ensure that it is managed sustainably. Despite these challenges, the government’s efforts at Muthalapozhy and other coastal regions in Kerala are demonstrating the critical importance of effective coastal management.

Looking Ahead: The Future of Coastal Management in Kerala

The future of coastal management in Kerala relies on continued investment in dredging and modern harbor facilities. With rising sea levels and increasing frequency of extreme weather events, effective dredging practices will be essential for safeguarding the state’s coastline.

The use of modern technology and dredging methods, including automated dredgers and real-time environmental monitoring, will play a key role in improving the efficiency and sustainability of these projects. As the government plans for more dredging operations along Kerala’s coastline, it is crucial that these efforts are integrated into a broader strategy for coastal protection and economic development.

Conclusion

Dredging plays a pivotal role in preventing floods and tidal surges in Kerala’s coastal regions. By removing sediment buildup and maintaining navigable waterways, dredging ensures the safety of local communities and the health of the coastal environment. The ongoing efforts at Muthalapozhy, along with other dredging projects in Kerala, highlight the need for continued attention to coastal management in the face of increasing challenges posed by climate change and rapid urbanization. The combination of effective dredging practices and government support is vital for securing a safe and prosperous future for Kerala’s coastal regions.