Hydropower projects vulnerable to warming climate and increased precipitation

  • Studies have hinted at the impact of climate change on hydropower projects, which are becoming more prone to the impacts of extreme weather events.
  • Indian government records show that extreme weather events have affected hydropower projects in the last few decades.
  • Experts and researchers advocate measures to control the impact of climate change, including climate risk assessment of such projects before commencement and investing more in climate-resilient structures.

Climate change can significantly alter hydropower generation capacity, notes a study published by the Indian Institute of Technology (IIT), Gandhinagar.

The study that appeared on February 17, 2023, claimed that with the anticipated increase in precipitation and warming, the power generation capacity of the majority of the Indian hydro projects would rise. But it would also expose the hydropower projects to increased risks, such as flooding and dam breaks.

The study examined the hydropower generation of 46 major hydropower dams in the country. It found that in a warmer projected climate (up to 5 degrees Celsius) and increased projected precipitation (between 5%-33%), the inflow of water to reservoirs of major dams is likely to increase by 7% to 70%, depending upon the region. This increased inflow, could, in turn increase (9%-36%) hydropower generation in most dams in the future.

The impact of these changes in reservoir storage and streamflow, on hydropower generation, indicates that hydropower is susceptible to climate change, noted the study. It found that hydropower projects in central India are likely to see higher inflow.

Read more: Chamoli floods trigger concerns against rapid development in the Himalayan region

NTPC dam damaged by the floods in 2021 in Chamoli. With the increase in precipitation and warming, hydropower projects in India will be exposed to flooding and dam breaks. Photo by Hridayesh Joshi for Mongabay.

“A simultaneous rise in extreme inflow and high reservoir storage conditions is projected under future climate for most dams. However, future climate changes project a favorable hydroclimate for hydropower production, with the associated risks related to extremes,” the study said. It also added that considerable adaptation measures would be needed to tackle the extremes in the future.

“Our findings can provide crucial insights related to projected changes in hydroclimate and hydropower for the major dams in India to planners and policymakers. In addition, we highlight the challenges and opportunities associated with climate change mitigation and adaptation in the context of hydropower in India under the warming climate. Our findings emphasise the need for reliable early warning systems that can assist reservoir operations in the future,” the authors said in their study.

Execution is key

Hydropower project damages due to extreme weather events are not new to India. According to documents from the Central Electricity Authority (CEA), between 1974 and 2008, at least 24 hydropower projects were affected due to flooding, which disrupted their normal functioning and performance. While 19 of these projects were affected during their operation and maintenance phase, seven were affected during their construction period, the report said.

Vishnuprayag dam in Uttarakhand damaged by flash floods in 2013. Between 1974-2008, atleast 24 hydropower projects were affected due to flooding. Photo by International Rivers/Flickr.

Hydropower projects in India are the third largest source of electricity, with a share of 11% of India’s total installed capacity, after coal (50%) and renewable sources (30%) of energy. India has 211 large hydro projects (above 25 Megawatt) in operation with a cumulative installed capacity of 46.8 GW. Another 41 hydroelectric projects (HEP) are under construction totalling 17 additional GW of planned production. They include 30 large HEPs in the fragile Himalayan region which are under the construction phase.

After the uproar over the Joshimath incident, the Ministry of Power recently told the Indian Parliament that all large hydropower projects get the green signal only after environmental clearances of the Ministry of Environment, Forest and Climate Change (MoEF&CC) that too after a comprehensive assessment by an Expert Appraisal Committee (EAC).

Several agencies also assess the hydro projects’ Detailed Project Reports (DPR). It includes scrutiny from the Geological Survey of India (GSI), Central Electricity Authority (CEA), Central Water Commission (CWC), and Central Soil and Materials Research Station (CSMRS).

Guidelines for formulation of DPR for large hydro projects categorically say that the project developers need to analyse the general climatic conditions of the project site and its seismic potential, investigate the meteorological conditions there, make disaster management plans, and estimate its cost besides working on other aspects. The cost of the disaster management plan and protecting the environment must be part of the project’s cost estimates.

However, experts from the sector claimed that adequate robust climate risk assessments before starting such projects are hardly done, leading to their exposure to several climate-related hazards.

“I have written several letters to the Ministry of Environment and Forests and its Expert Appraisal Committee on River Valley Projects in the last 15 years. We had been demanding robust climate risk assessment studies before sanctioning hydro projects and dams, especially in the fragile Himalayan regions. There is a need for a course correction in policies governing hydro projects. There should be studies to determine the area’s existing disaster potential before these projects. Also, on what additional disaster elements the new projects can add in such areas post construction and operations,” Himanshu Thakkar, Coordinator at the South Asia Network on Dams, Rivers and People (SANDRP), told Mongabay-India.

A representative image of a dam under construction. The Ministry of Power has asked the parliament to give a green signal for all large hydropower projects only after environmental clearances of the Ministry of Environment, Forest and Climate Change (MoEF&CC) and after a comprehensive assessment by an Expert Appraisal Committee (EAC). Photo by International Rivers.

The hydropower developers also validated the lack of climate risk assessment studies, hinting towards a lack of reflection on the risks of these projects from the climate point of view. The National Hydro Power Corporation (NHPC), one of the significant public sector HEP developers in India, in an email response to Mongabay-India, said that it had yet to undertake any study on the risk of climate change on its hydropower projects. As released by the Ministry of Power, the 2022 document on disaster preparedness of the energy sector also bats for such studies.

Towards climate resilience

The International Energy Agency (IEA), which studied the future impacts of climate change on hydro projects in Latin America and Africa, claimed that the resilience of HEPs is paramount for the sector. “Climate resilience is essential for hydropower to continue delivering its function in the path of clean energy transitions. Without enhancing climate resilience, adding new capacity and flexibility services can quickly be disrupted by increasingly frequent extreme precipitation events and their associated hazards,” it said in its report.

The IEA claimed that countries need to take ‘soft measures,’ including policy changes like incentivising HEP developers for roping in climate resilient structures, regulating its mandatory compliance, and others. It also advocated for ‘hard measures’ which looked at making the structures and designs more robust to counter the impact of climate change.

The IIT Gandhinagar study also advocated advanced early warning systems (EWS) to prepare the HEPs better to counter adverse conditions. However, Thakkar from SANDRP pointed out that these are not new recommendations. The delay happens at the execution level.

“EWS was long recommended by the Ravi Chopra Committee in 2014 and even earlier. But even after that, in most HEPs, it remains non-existent, which could have saved many lives. Be it the February 2021 Chamoli floods or many other floods at HEPs in Himalayan states, the lack of EWS led to more losses. Even today, hardly any HEPs in India have advanced EWS systems with credible, transparent and accountable governance. Moreover, all information related to the EWS must be mandatorily and promptly in the public domain for everyone to know and to fix accountability,” Thakkar added.

Only after the 2021 Tapovan flash floods at a hydro project managed by the National Thermal Power Corporation (NTPC) did the union minister RK Singh announce the installation of EWS at the NTPC HEPs in the hilly regions.

Jayanta Bandhopadhay, Professor (retired) at the Indian Institute of Management (IIM), Calcutta, told Mongabay-India that India needs to re-look at its existing policies and revise them to make them more contemporary on account of the rising new threats from global warming and climate change.

“A lot of regulations, standards, and specifications governing the hydroelectric powers in India are quite old and need revision and upgradation to cater to the changing demands of global changes. However, the impact of climate change on hydropower is not confined to India alone and is a global phenomenon. But we still need to figure out the precise quantum of greenhouse emissions and global warming in the future and thus cannot predict the precise impact of climate change. The climate problems are thus poorly understood and tough to forecast,” Bandyopadhyay told Mongabay-India.

He also said that HEP developers follow the set standards and guidelines for design and construction. “First, there is a lack of information on the challenges. Secondly, we lack well-tested technologies to help design climate change resilient structures.”

However, through their analysis, the latest CEA document on disaster management of the energy sector claimed that most of the flooding and damages to HEP were reported during the operations period. It also pointed out that most of the HEPs that were affected due to flooding were found using ‘Francis Turbines,’ which seemed more vulnerable to damaging the powerhouses in the case of floods. The report claimed that the HEP developers may have prevented many of these threats with timely actions.

“It is observed that the extent of the damage and rehabilitation period could have been minimised if adequate measures had been taken at design, construction, and during operational stages of the hydropower houses. In some cases, even flooding of powerhouses could have possibly been prevented,” the report said. It also advocated for some mitigation measures like not constructing HEPs along the floodplains of rivers, locating such projects at higher altitudes, using salt water resistant structures, and simulation studies, among others.

At the global level, the International Hydropower Association (IHA) 2019 also prepared a guide to do climate-resilient hydroelectric power projects. It advocated four steps for these HEPs to make them robust to counter climate change effects. These included-climate risk screening, initial analysis, climate stress test, climate risk management and monitoring, reporting, and evaluation.


Banner image: The Hirakud dam in Odisha. Several studies hint at the direct impact of climate change on hydropower projects. The projects will be vulnerable and are more prone to disasters. Photo by Amudha HariHaran/Flickr.

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