Soil piping, floods: Rains and repercussions add to Kerala monsoon woes

Kerala is multi-hazard-prone, and its districts have been asked to keep an eye on floods, landslides, wind, lightning, and soil piping.

ByDileep V Kumar

Published Jun 02, 2024 | 10:01 AM Updated Jun 02, 2024 | 12:28 PM


The Southwest Monsoon has arrived in Kerala, bringing much-needed respite from the scorching summer.

However, it has brought with it concerns about potential natural calamities.

Kerala being a multi-hazard-prone state, districts have been asked to keep an eye on hazards like floods, landslides, wind, lightning, and soil piping.

They have also been directed to ensure emergency preparedness and response capacity based on the Orange Book of Disaster Management.

Also read: South West monsoon intensifies in Kerala, disrupts normal life

Being cautious

Talking to South First, an official from the Kerala State Disaster Management Authority (KSDMA) said, “The state is multi-hazard-prone.”

He explained: “Around 14.5 percent of the state is flood-prone. Also, 14.4 percent of the state is landslide-prone and 55.5 percent of the coastline is prone to coastal hazards.”

He added, “It is expected that the southwest monsoon showers will be above normal. Extreme rainfall events might happen. Due to this, chances are high that floods, soil piping and landslides might occur.”

The official noted: “This underscores the need for preparedness and vigilance. The public’s cooperation and adherence to safety guidelines will be crucial in navigating through this challenging period.”

The state witnessed the most devastating series of floods and landslides in the years 2018 and 2019, which affected millions of people.

It caused a huge number of casualties as well as incurred heavy economic, social, and infrastructural damages.

The state was hit by torrential rains in 2021 as well, causing flooding and triggering a series of landslides.

Of the various hazards during the monsoon, it is said that soil piping is the much-feared hidden threat.

Also read: Severe flooding hits Kerala and Assam due to two cyclonic systems


Among the hazards associated with the monsoon, soil-piping — also known as tunnel erosion — is particularly feared for its insidious nature and the potential for sudden, catastrophic damage.

Soil-piping involves the subsurface erosion of soil, leading to the formation of underground tunnels or pipes.

These tunnels can collapse without warning, causing sinkholes and extensive damage to infrastructure and agricultural land.

In Kerala, all districts other than — except Thiruvananthapuram, Kollam, and Alappuzha — have reported the occurrence of soil piping-affected soils.

A study carried out by the National Centre for Earth Science Studies in 2016 found that many of the piping are located at Idukki and Kannur, Kasaragod, and then followed by Kozhikode, Palakkad, Ernakulam, Pathanamthitta, and Wayanad.

The study, titled “The Soil Piping in the Highlands and Foothills of Kerala to avoid the disaster”, also highlighted that soil piping is the main reason for the land subsidence in the Western Ghats in Kerala.

Meanwhile, most of the tunnelling occurs where deforestation has taken place.

The study then observed, “Erosion due to piping in an area is like cancer affecting the human body. If unattended, it will spread and destroy vast amounts of valuable land in the state.”

Also Read: 4 dead as torrential rains lash Kerala


Landslides are another grave concern during the monsoon season in Kerala, particularly in the hilly and mountainous regions.

The incessant rains can weaken the soil structure, triggering landslides that can devastate communities, block roads, and cause loss of life and property.

The KSDMA in its report on Extreme Rainfall Over Kerala in 2021 observed: “It is a fact that every year, the number of disaster events like extreme rainfall events and landslides are increasing in Kerala.”

A landslide is a rapid mass-wasting process that causes the downslope movement of a mass of rock, debris, or earth material under the influence of gravity.

In another report that analysed landslide susceptibility, assessment, and preparedness strategies of a local body, KSDMA observed, “Slope failures are very common along the hill ranges of Kerala, particularly during the monsoon period.”

It added: “In hilly regions, instability of slopes is one of the major natural hazards that cause losses to lives and property. The Western Ghats is the most prone physiographic unit for landslides.”

It also observed: “The nature of landslide and material involved vary from location to location and it is observed that it is not a single factor that causes the failure but the cumulative effect of many parameters led to disaster.”

Room for rivers

The annual arrival of the monsoon in Kerala is often regarded as a double-edged sword.

While it brings life-giving water to the parched land, it also unleashes the fury of floods, displacing families and wreaking havoc on infrastructure.

This year, as the rains are expected to lash the state, experts are once again highlighting a potential solution that remains only partially implemented: Providing “room for the river”.

The concept is simple: Give rivers the space they naturally require to meander and absorb excess water during monsoons.

This can involve strategically planned embankments further inland, allowing floodplains to function as natural buffers, and restoring lost wetlands that act as sponges.

“The state had this intricate network of rivers. But for decades it witnessed increasing encroachment on these floodplains.  Construction of houses, buildings, and even commercial establishments along riverbanks has choked the natural flow, leading to overflowing rivers and devastating floods,” said an official from the Revenue Department.