Increasing Risks of Flash Floods: Policy & Infrastructural Gaps

Author: Anusha Arif

At the beginning of October 2023, the glacial-fed Lhonak Lake in the northern part of the state of Sikkim triggered a flash flood in the Teesta River basin. The flash floods have claimed 74 lives, and more than 100 people have been reported missing. 

The disaster unfolded due to a cloudburst that led to a sudden rise in water levels beyond the lake’s holding capacity. Sikkim is considered one of the states most vulnerable to the effects of climate change in India. In its state action plan, the government recognised the erratic rainfall patterns; however, there was a noted decrease in annual precipitation between 1957 and 2009.  An increase in risk is caused by the rapid melting of the glaciers identified in the year 2021. A combined study by researchers from the USA, Austria, Switzerland and India was conducted to determine the region’s future susceptibility to a Glacial Lake Outburst Flood (GLOF). The study found that many settlements and assets along the river channel at Chungthang were exposed to future GLOFs. The flash flood has also caused significant disruption to the roads, highways and homes, washing away nearly 13 bridges & 1320 houses. Beyond that, it has caused considerable damage to the Urja Dam at Chungthang, as predicted by the 2021 study. 

The state government’s delay in action has invited criticism. The Urja dam, located 5000 feet above sea level, and the connected powerhouse were washed away in the floods and areas such as Mangan, Dikchu, Singtam, Rangpo, Chungthang and Bardang were affected severely. The Chief Minister had received the news about the flood at 10.40 pm; however, the dam officials were allegedly alerted too late, delaying lifting the spillway gates. Another factor that posed a question was why the dam was running beyond its capacity & failures of the manual alarm system. 

The risks of flash floods have significantly increased worldwide; in India, more than 40 million hectares (mha) are flood-prone. Most flash floods have been attributed to poor water-absorbing capacity of soil, higher precipitation in areas with low evacuation infrastructure, blockages in the draining systems, natural or man-made dam collapse and obstructions in the flow of water. In India specifically, the risks of flash floods have also been associated with growth factors that include geographical, socio-economic, geopolitical and mismanagement.

High Flood Risks: Forums & Services

Among many developing countries, flash floods are considered one of the primary risks from extreme climatic events due to rising sea levels and erratic rainfall. The World Bank estimates that 1.81 billion people worldwide are at a direct risk from intense flooding. The UN Environment Programme Adaptation Gap Report 2021 pressed on the adaptation gap due to financing for extreme climate events such as floods and droughts. 

At present, India, Bangladesh, Indonesia and Pakistan face severe threats of damage due to floods, owing to their large population percentages. Even countries such as the Netherlands & China have 58.7% and 27.5% of their population, respectively, exposed to risk from floods. The Ministry of Earth Sciences under the World Meteorological Organization in 2021 launched the Flash Flood Guidance Services. The Guidance Service is the first for South Asian countries India, Bangladesh, Bhutan, Nepal and Sri Lanka, which face an increased risk with India as a regional centre. All five countries presented a case study for flash floods in their region at the operational workshop for the Flash Flood Guidance Services for South Asia. India presented a case for the central, west coastal part of India, presenting synoptic conditions for the 29th May 2018 for heavy rainfall that caused flooding in Mangaluru.

The recognition in international climate policy that comes from identifying loss and damages in the aftermath of a natural disaster is important; however, they remain secondary. Primarily, in the event of extreme climate disasters, adaptation and resilience building must occupy centre stage to minimise the damage caused to communities from such occurrences, especially with the increase in frequency caused by climate change. The government must adopt a risk assessment strategy, especially for remote and isolated areas with more significant risks. Updating infrastructure and regular checks are required to maintain the standard for appropriate prevention of damage from such risks. While international climate law recognises flash floods as an emerging threat, there is no appropriate forum for knowledge sharing to mitigate the risks, and sufficient focus has not been given to the specific threats that arise. One major takeaway from the Sikkim flash floods is that neither the infrastructure nor disaster management operations are ready to reduce the risks of flash floods or to minimise the damage caused to life and property in India.