Category: Water

Climate change to cause havoc with Mediterranean water resources says European Commission

Climate change to cause havoc with Mediterranean water resources says European Commission

By Will Bugler

The Mediterranean will face mounting challenges to manage its water supplies as climate change drives droughts and floods according to a report by the European Commission. The report, which focusses on the effects of 2˚C of warming, indicates that there is likely to be a divide between central and northern Europe, which can expect more rainfall overall, and the Mediterranean which will suffer drought.

The study, which assumes that land use and water demand remains constant, shows that river flows in the Mediterranean are expected to fall overall, but the region will still experience extreme rain events that will lead to river flooding. This will pose considerable challenges for water dependent sectors such as agriculture. Spain, Portugal and Greece face severe droughts during the summer season which will limit the amount of water available for cooling heavy industry and energy plants.

Groundwater resources are also expected to fall limiting the region’s ability to abstract water and increasing costs. This, coupled with lower soil moisture content, could lead to crop failure and reduced yields. The situation in countries such as Spain is critical, with freshwater resources expected to be insufficient to meet local water needs under a 2-degree warming.

The report urges governments to take action to adapt to such climate impacts through integrated water management policies. Demand for fresh water will need to reduce considerably, through measures such as increasing irrigation efficiency, efficiency increases in cooling processes in industry and energy production, public water savings, a better management of water resources by, for instance, storing winter water in hydropower reservoirs for irrigation water use in summer.

Download the report by clicking here.


Cover photo by Andres Flajszer/Wikimedia Commons (CC BY-SA 3.0): Aqueduct in Los Monegros desert, Aragón, Spain.
Toward a flood-resilient Kolkata

Toward a flood-resilient Kolkata

By Elisa Jiménez Alonso

Kolkata’s flood forecasting and early warning system (FFEWS), supported by the Asian Development Bank (ADB), will be India’s first comprehensive city-level early warning system. Designed to provide forecasts and real-time updates using sensors installed in key points throughout the city, the system will enable informed decision making before and during disasters.

How the FFEWS works. Source: ADB.

The system includes a series of complementary components: weather forecasts; flood models for various intensities of rainfall; real-time information on key pump status, sump and canal water levels, actual rainfall, inundation levels, among others; and a messaging system to provide warnings and real-time information to city officials and citizens. The FFEWS will enable flood-informed urban planning, improve the flood awareness and safety of Kolkata’s communities, reduce economic losses and flood-impacts on livelihoods, and reduce the impacts of flood-induced traffic jams.

The system was designed with the people of Kolkata at its centre and aims to empower them so they can act quickly and appropriately to reduce flood risks. During the design phase key stakeholders were consulted to identify the best places for monitoring. Consultation with citizens and borough engineers helped identify locations for real-time data collection on rainfall and flood risk.

Since 2000, phased investments carried out through ADB-supported projects have already helped reduce Kolkata’s flooding problems by about 4,800 hectares, planned projects are expected to provide a further reduction of roughly 6,000 hectares. The projects are enabling the city to systematically expand the sewerage and drainage network in Kolkata, including flood-prone areas; increasing sewage treatment capacity; improving water supply through reductions in non-revenue water; managing solid waste; and increasing operational efficiencies and building capacity to better sustain the services it provides.

Download the full publication and learn more about the key features and benefits by clicking here.

Heavy rains and blocked drains: Nairobi’s recipe for floods

Heavy rains and blocked drains: Nairobi’s recipe for floods

By Sophie Mbugua, Climate Home News

Dirty flood waters, impassable roads and submerged slums have become the norm every time it rains in Nairobi, Kenya’s capital city.

In August, the authorities took drastic action, bulldozing around 2,000 buildings in the flood plain, including shopping malls worth millions of dollars. After a lull, they are due to resume demolitions this month, national media reports.

The ongoing October-December rainy season is on track to bring – mercifully – average volumes of water. Yet the city’s flood risk is rising, as climate change brings more extremes of rainfall. Experts tell Climate Home News better waste management, urban planning and warning systems are needed to protect its growing population.

Numerous informal and formal settlements without adequate sewerage and sanitation services edge onto the three Nairobi Rivers: Mathare, Ngong and Nairobi.

At Hazina village, one of 22 villages in south B division along the Ngong, the river chokes with refuse, making the water hardly visible.

“It’s the village’s dumping site,” Anne Keli, a 46-year-old mother of 12 tells Climate Home News. She has lived in the village for two decades and says flooding has been particularly bad in the past two years.

“The water reaches the village at a high force compared to previous years but gets stuck due to the plastics, paper bags and assorted waste in the river, blocking its flow,” Keli says. “Since we are on a lower area, the run-off from higher areas headed to the river has no place to go as the river is full. So, where else does it go? Into our houses.”

During the long rains in April, Keli’s family left their flooded home and camped in the county commissioner’s grounds. She lost around 30,000 Kenyan shillings ($290) worth of goods from the shop she runs less than a kilometre from the river.

The provincial administration made some efforts to clean the river during the flooding, but as soon as the rainy season ended it clogged up again, Keli says. “People keep building close to the river, reducing its size by day. People are asked to remove the structures with every flood but after the rains, everything moves back to normal.”

Kenya Meteorological Department (KMD) has installed more than 72 monitoring stations across the country in a bid to provide more timely and precise information.

Brian Chunguli, a county disaster management official, says a UK-funded programme will allow them to monitor live flooding levels from satellites and alert residents as waters rise.

“We hope to respond before flooding happens, and collected data will inform the disaster policy and interventions as we will compare long term data showing at what rainfall levels has certain areas flooded,” explains Chunguli.

Long-term projections of East African rainfall vary, with most climate models predicting heavier inundations as temperatures rise.

Mary Kilavi, the Nairobi County director of meteorological services, is mapping the areas likely to flood in Nairobi given a specific amount of rainfall. South B and South C on the Ngong river are hotspots, along with Mathare by the Nairobi river.

“We are using a model that simulates surface water flooding using previous city flooding data corrected over time,” she explains. “We want to find out with a specific amount of rainfall, which areas will flood.”

This will help the authorities to move beyond a reactive approach to systematic preparation, she says. “Since weather is given in probabilistic terms, systems don’t act fast. We will establish the probability of achieving the estimated flood causing rainfall, then with stakeholders, agree at what point to act, the actions to take and funds to be set aside for the actions.”

The solutions range from cleaning up waste to creating green urban spaces and changing land management upriver. Many of these face political, as well as practical, obstacles.

There is a directive against building within 30 metres of the riverside, for example, but it is haphazardly enforced. Many owners of the recently demolished structures insisted they had permits to build there.

“It requires funds and land to relocate and rebuild the structures amid political interference, as area politicians incite the residents not to move,” says Barre Ahmed, assistant county commissioner for Starehe sub county.

Dr Lawrence Esho, chair of the Kenya Institute of Planners, calls for a drainage master plan to cover the entire metropolitan area.

“We have a flooding crisis but the issue is bigger than the illegal buildings. It is more of the uphill destruction of land which we are doing nothing about, too much concrete pavements aggregating the run off flow, blocked drains and climate change,” says Esho. “Over the last 20 to 25 years the city has also gone through the change from bungalows built over a huge area to high-rise apartment blocks… without a drainage city master plan change.”

Builders should leave gaps between pavements for grass “to allow the water sip under when it rains,” he advises.

In the meantime, Keli can only make sure she has a quick exit strategy ready. She says: “I worry at every drizzle. But this time, I am prepared with a bag packed for any eventuality to rescue my children. As for the shop, there is little I can do. Until the river is cleaned, I still believe this village will flood if the rain keeps coming as they did these two years.”


This article originally appeared on Climate Home News and is shared under Creative Commons license. This article was produced as part of an African reporting fellowship supported by Future Climate for Africa.

Cover photo by Sophie Mbuaga: The Ngong river is choked with garbage as it passes through Hazina village.
Global water supply shrinks in rainier world

Global water supply shrinks in rainier world

By Tim Radford

The global water supply is dwindling, even though rainfall is heavier. Once again, climate change is to blame.

Even in a world with more intense rain, communities could begin to run short of water. New research has confirmed that, in a warming world, extremes of drought have begun to diminish the world’s groundwater – and ever more intense rainstorms will do little to make up the loss in the global water supply.

And a second, separate study delivers support for this seeming paradox: worldwide, there is evidence that rainfall patterns are, increasingly, being disturbed. The number of record-dry months has increased overall. And so has the number of record-breaking rainy months.

Both studies match predictions in a world of climate change driven by ever-higher ratios of greenhouse gases in the atmosphere, from ever-increasing combustion of fossil fuels. But, unlike many climate studies, neither of these is based on computer simulation of predicted change.

Each is instead based on the meticulous analysis of huge quantities of on-the-ground data. Together they provide substance to a 40-year-old prediction of climate change research: that in a warming world, those regions already wet will get ever more rain, while the drylands will tend to become increasingly more arid.

As global temperatures creep up – and they have already risen by 1°C in the past century, and could be set to reach 3°C by 2100 – so does the capacity of the atmosphere to absorb more moisture. It follows that more rain must fall. But at the same time more groundwater evaporates, and the risk of damaging drought increases.

“What we did not expect, despite all the extra rain everywhere in the world, is that the large rivers are drying out”

Australian scientists report in the journal Water Resources Research that they studied readings from 43,000 rainfall stations and 5,300 river monitoring sites in 160 countries. And they confirm that even in a world of more intense rain, drought could become the new normal in those regions already at risk.

“This is something that has been missed. We expected rainfall to increase, since warmer air stores more moisture – and that is what climate models predicted too,” said Ashish Sharma, an environmental engineer at the University of New South Wales.

“What we did not expect, despite all the extra rain everywhere in the world, is that the large rivers are drying out. We believe the cause is the drying of soils in our catchments. Where once these were moist before a storm event – allowing excess rainfall to run off into rivers – they are now drier and soak up more rain, so less water makes it as flow.”

The study matches predictions. Just in the last few months, climate scientists have warned that catastrophic climate change could be on the way, and that the double hazard of heat waves and sustained drought could devastate harvests in more than one climatic zone in the same season; and that those landlocked rainfall catchment areas that are already dry are becoming increasingly more parched.

But over the same few months, researchers have established repeatedly that tomorrow’s storms will be worse and that more devastating flash floods can be expected even in one of the world’s driest continents, Australia itself.

Less water available

Of all rainfall, only 36% gets into aquifers, streams and lakes. The remaining two thirds seeps into the soils, grasslands and woodlands. But more soil evaporation means less water is available from river supplies for cities and farms.

US researchers have already confirmed that if soils are moist before a storm, 62% of rainfall leads to floods that fill catchments. If soils are dry, only 13% of the rain leads to flooding.

“It’s a double whammy. Less water is ending up where we can’t store it for later use. At the same time, more rain is overwhelming drainage infrastructure in towns and cities, leading to more urban flooding,” said Professor Sharma.

“Small floods are very important for water supply, because they refill dams and form the basis of our water supply. But they’re happening less often, because the soils are sucking up extra rain. Even when a major storm dumps a lot of rain, the soils are so dry they absorb more water than before, and less reaches the rivers and reservoirs”, he said. “We need to adapt to this emerging reality.”

In the second close look at change so far, researchers based in Germany report in the journal Geophysical Research Letters  that they analysed data from 50,000 weather stations worldwide to measure rainfall on a monthly basis.

Climate drives aridity

The US has seen a more than 25% increase of record wet months in the eastern and central regions between 1980 and 2013. Argentina has seen a 32% increase. In central and northern Europe the increase is between 19% and 37%; in Asian Russia, it has been about 20%.

But in Africa south of the Sahara the incidence of very dry months has increased by 50%. “This implies that approximately one out of three record dry months in this region would not have occurred without long-term climate change,” said Dim Coumou, of the Potsdam Institute for Climate Impact Research.

“Generally, land regions in the tropics and sub-tropics have seen more dry records, and the northern mid- to high-latitudes more wet records. This largely fits the patterns that scientists expect from human-caused climate change.”

His colleague and lead author Jascha Lehmann said: “Normally, record weather events occur by chance and we know how many would happen in a climate without warning. It’s like throwing a dice: on average one out of six times you get a six.

“But by injecting huge amounts of greenhouse gases into the atmosphere, humankind has loaded the dice. In many regions, we throw sixes much more often, with severe impacts for society and the environment.

“It is worrying that we see significant increases of such extremes with just one degree of global warming.”


This article was originally published on Climate News Network.

Cover photo by Oxfam/Flickr (CC-BY 2.0): Water shortage in Ethiopia.

This New Climate – Episode 2: Running dry – dealing with water scarcity

This New Climate – Episode 2: Running dry – dealing with water scarcity

In the second episode of This New Climate, host Will Bugler explores why it is so difficult to manage water resources and presents Water2Invest – a new tool that helps decision makers make smarter choices about managing water supply and demand. The world’s population has tripled over the last 100 years, but according to the UN, water demand has been growing at more than twice that rate making water scarcity one of the defining challenges of our time. And climate change will only compound the problem. Water2Invest, aims to help decision makers to take the right choices when investing in solutions to tackle water scarcity, potentially providing a powerful new tool to help tackle this crisis.

Episode guests: Gisela Kaiser from the City of Cape Town, Mark Bierkens from Utrecht University, and Daniel Zimmer from EIT Climate-KIC.

This New Climate is an Acclimatise production.

Water2Invest is an EIT Climate-KIC supported innovation initiative.

Further information:

Water2Invest

City of Cape Town

Utrecht University

Climate-KIC

Why wastewater matters, and innovation is indispensable

Why wastewater matters, and innovation is indispensable

By Christian Walder, Asian Development Bank

Human nature is wired to forget what it does not see, and to ignore what it does not deem as attractive. In our urban systems, that would be wastewater.

Who takes a second to think about where all water discharged, flushed, or processed goes? Hardly anyone, and yet this is a vital piece in the machinery that makes our world go round.

Even data on wastewater generated globally is not systematically monitored. For municipal and industrial wastewater in 2015, estimates put it at 940 cubic kilometer per year.

What is certain, on the other hand, is that 80% of the world’s wastewater is released to the environment without treatment, and this number goes up to over 95% in some least developed countries, according to the UN.

On a recent stroll around Chinatown in Manila, that statistic became all too real. My family and I were initially fascinated with the flurry of activity, the crowds, the shops and Chinese restaurants, as well as the gold and jade dealers. But when we came to a bridge crossing one of the small estuaries of the Pasig River that feeling and excitement from the exotic suddenly stopped. We were faced not with an idyllic creek but a gray, almost blackish body of water full of garbage.

Megacities such as Metro Manila, despite important appearances of progress, still do not have adequate sanitation and wastewater treatment. It is estimated that more than 11 million of Metro Manila’s population is using on-site sanitation facilities and that there are more than two million septic tanks installed in the Philippines’ capital region.

The technical design and construction quality of the septic tanks is often poor, and they are not regularly emptied. That’s when the effluent typically flows into open drains and water bodies. In neighboring Indonesia, 64% of households have septic tanks, but only 4% of the septage is treated.

Water systems are already beset with immense challenges such as water scarcity, increasing demand due to urbanization and population growth, and climate change impacts. Increased discharges of untreated wastewater add to the pollution of water sources, and further diminish water quality.

To address these issues, radical changes within the water sector are required. Promising examples include innovative solutions for wastewater treatment, distributed or on-site treatment of wastewater, resource recovery, and institutional and organizational reforms that can make the “out of sight, out of mind” practice obsolete.

In Biñan, a city just south of Metro Manila in Laguna province, there is a wastewater treatment plant that has begun using an alternative approach. The facility is located in a densely populated area and has applied a nature-based technology—comprised of plants, microorganisms, biofilms, and engineered media—to break down the wastewater in a biological process that requires less energy and produces less sludge compared to a conventional centralized treatment plant.

Watch the video below to find out more:

Why wastewater matters, and innovation is indispensable from ADB Knowledge on Vimeo.


Christian Walder is an Urban Development Specialist (Water Supply and Sanitation) at ADB’s Sustainable Development and Climate Change Department. He is excited about infrastructure financing and the application of innovative, high-level technologies for urban development projects. Before joining ADB in 2018 he worked in the private sector on projects in Central and Eastern Europe, Namibia, Egypt, and India in the various fields of urban water management: water supply, municipal and industrial wastewater treatment, and plant operations.

This article was originally published on Asian Development Blog, access it by clicking here.

Cover photo by Mike Gonzalez/Wikimedia Commons (CC BY-SA 3.0): A shanty town in Manila, beside the Manila City Jail. This picture was taken from Recto LRT Station.
‘Eternal’ Swiss snow is melting faster

‘Eternal’ Swiss snow is melting faster

By Paul Brown

Scientists say stretches of “eternal” Swiss snow are melting faster than 20 years ago, with serious impacts for water supply and tourism.

Parts of Europe’s alpine mountain chain are undergoing accelerating melting, as the “eternal” Swiss snow thaws ever faster, threatening both the skiing industry and the nation’s water supply.

Over a period of only 22 years, thousands of satellite images have provided irrefutable evidence that an extra 5,200 square kilometres of the country are now snow-free, compared with the decade 1995-2005.

Researchers from the University of Geneva and the United Nations Environment Programme have used data from four satellites which have been constantly photographing the Earth from space, compiling a record published by the Swiss Data Cube, which uses Earth observations to give a comprehensive  picture of the country’s snow cover and much else besides, including crops grown and forest cover.

It is the loss of snow cover that most disturbs the scientists. What they call “the eternal snow zone” still covered 27% of Swiss territory in the years from 1995 to 2005. Ten years later it had fallen to 23% – a loss of 2,100 sq km.

The eternal snow line marks the part of Switzerland above which the snow never used to melt in summer or winter. It is also defined as the area where any precipitation year-round has an 80-100% chance of being snow.

“We have stored the equivalent of 6,500 images covering 34 years, a feat that only an open data policy has made possible”

Other parts of the country, including the Swiss Plateau (about 30% of Switzerland’s area), the Rhone Valley, the Alps and the Jura mountains are also losing snow cover, adding up to the 5,200 sq km total. These areas, below the eternal snow line, have until now usually had lying snow in the winter.

The study was launched in 2016 on behalf of Switzerland’s Federal Office for the Environment. Knowing the extent of snow cover and its retreat is essential for developing public policies, the researchers say.

Beyond the economic issues linked to the threat to ski resorts – a familiar area of concern, heightened by this latest research, as many of them now face shortened seasons or outright abandonment – other problems such as flood risk and water supply are coming to the fore. Snow stores water in the winter for release in spring and summer, for both agriculture and drinking water.

Currently the increasing loss of ice from glaciers in the summer is making up for the missing snow, but previous work by scientists has shown that in the future, when glaciers disappear altogether, Switzerland could face a crisis.

The researchers have relied on the information available from the Data Cube to establish what is happening on the peaks. By superimposing repeated pictures of the same place over one another they have been able to observe small changes over time.

Wealth of data

The data was made freely available to researchers. One of them, Grégory Giuliani, said: “We have stored the equivalent of 6,500 images covering 34 years, a feat that only an open data policy has made possible. If we had had to acquire these images at market value, more than 6 million Swiss francs would have been invested.

“Knowing that each pixel of each image corresponds to the observation of a square of 10 by 10 meters, we have 110 billion observations today. It is inestimable wealth for the scientific community.”

Apart from snow cover scientists are worried about many other changes taking place in Switzerland because of climate change. They already know that glaciers are melting at record speeds and plants, birds and insects are heading further up the mountains, but there is much else to be gleaned from the new data base.

The Data Cube offers the possibility of studying vegetation, the evolution and rotation of agricultural areas, urbanisation and even water quality, as satellite images can be used to monitor three essential indicators in lakes and rivers: suspended particles, whether organic or mineral; chlorophyll content; and surface temperature.

The data are freely accessible, not only to scientists worldwide but also to the public, making it easy to compare data for specific areas of the territory at different times. “Our ambition is that everyone should be able to navigate freely in Swiss territory to understand its evolution”, said Grégory Giuliani.


Paul Brown, a founding editor of Climate News Network, is a former environment correspondent of The Guardian newspaper, and still writes columns for the paper.

This article was originally published on Climate News Network.

Cover photo by Steve Evans/Flickr (CC BY-NC 2.0)
What can other cities learn about water shortages from ‘Day Zero’?

What can other cities learn about water shortages from ‘Day Zero’?

By Lucy Rodina, University of British Columbia and Kieran M. Findlater, University of British Columbia

Cape Town was set to run dry on April 12, 2018, leaving its 3.7 million residents without tap water.

“Day Zero” was narrowly averted through drastic cuts in municipal water consumption and last-minute transfers from the agricultural sector. But the process was painful and inequitable, spurring much controversy.

The city managed to stave off “Day Zero,” but does that mean Cape Town’s water system is resilient?

We think not.

This may well foreshadow trouble beyond Cape Town. Cities across the Northern Hemisphere, including in Canada, are well into another summer season that has already brought record-setting heat, drought and flooding from increased run-off.

Water crises are not just about scarcity

Water scarcity crises are most often a result of mismanagement rather than of absolute declines in physical water supplies.

In Cape Town, lower than average rainfall tipped the scales towards a “crisis,” but the situation was worsened by slow and inadequate governance responses. Setting aside debates around whose responsibility it was to act and when, the bigger issue, in our view, was the persistence of outdated ways of thinking about “uncertainty” in the water system.

As the drought worsened in 2016, the City of Cape Town’s water managers remained confident in the system’s ability to withstand the drought. High-level engineers and managers viewed Cape Town’s water system as uniquely positioned to handle severe drought in part because of the vaunted success of their ongoing Water Demand Management strategies.

They weren’t entirely mistaken — demand management has cut overall daily consumption by 50 per cent since 2016. So what went wrong?

Limits to demand management

First, Cape Town’s approach to water management was not well-equipped to deal with growing uncertainty in rainfall patterns — a key challenge facing cities worldwide. Researchers at the University of Cape Town argued recently that the conventional models long used to forecast supply and demand underestimated the probability of failure in the water system.

Second, Cape Town’s water system neared disaster in part because demand management seemed to have reached its limits. Starting late last year, the city imposed a limit on water consumption of 87 litres per person per day. That ceiling thereafter shrunk to 50 litres per person per day.

Despite these efforts, Cape Town consistently failed to cut demand below the 500-million-litre-per-day citywide target needed to ensure that the system would function into the next rainy season.

The mayor accused the city’s residents of wasting water, but her reprimanding rhetoric should not be seen as a sign that the citizens were non-compliant. The continuously shrinking water targets were an untenable long-term management strategy.

Buffers are key to water resilience

In the end, “Day Zero” was avoided primarily by relying on unexpected buffers, including temporary agricultural transfers and the private installation of small-scale, residential grey-water systems and boreholes in the city’s wealthier neighbourhoods. The former increased water supply and the latter lowered demand from the municipal system. These buffers are unlikely to be available next year, however, as the water allocations for the agricultural sector will not be renewed and there is uncertainty in the long-term sustainability of groundwater withdrawals.

For more than a decade, Cape Town has levelled demand, reduced leaks and implemented pressure management and water restrictions. This made Cape Town’s water system highly efficient and therefore less resilient because there were fewer reserves to draw from in times of unusual scarcity.

The UN Water 2015 report found that most cities are not very resilient to water risks. As water managers continue to wait for climate change models to become more certain or more specific, they defer action, paralyzing decision-makers.

If we really want our cities to be water-resilient, we must collectively change long-held ideas about water supply and demand. This will require technological and institutional innovation, as well as behavioural change, to create new and more flexible buffers — for example, through water recycling, green infrastructure and other novel measures.

Although Cape Town avoided disaster this year, that does not make it water-resilient. Despite the arrival of the rainy season, Cape Town is still likely to face Day Zero at some point in the future.

There’s a good chance that the city is not alone.The Conversation


Lucy Rodina, PhD Candidate, University of British Columbia and Kieran M. Findlater, , University of British Columbia. This article is republished from The Conversation under a Creative Commons license. Read the original article.

Cover photo from Pixabay (public domain).
First ever assessment of climate change influence on India’s hydropower plants points to increased generation potential

First ever assessment of climate change influence on India’s hydropower plants points to increased generation potential

Will Bugler

Climate change will have a significant impact on India’s hydropower plants, according to a new study. Changes in rainfall patterns, snowmelt and streamflow in India’s major rivers however, will affect the design and operation of India’s planned and current hydro plants. Amazingly however, the role of climate change on hydroelectric facilities in the country remains largely unexplored.

India is the world’s 7th largest producer of hydropower, and the predictable, low-carbon energy source is vitally important for the country’s ambitions to improve energy supplies and cut greenhouse gas emissions. With India’s population continuing to grow, the demand for clean energy will rise in the coming years. Hydropower offers considerable potential to meet some of this demand. Estimates suggest that the country uses less than 20 % of its total hydropower potential.

Dams must be built to last

As with other large infrastructure developments, proper consideration of climate change on hydroelectric facilities is essential. The lifespan of a large, concrete dam can extend to well over 100 years. A hydropower dam built today will be operational in a considerably different climate in its later life.

The study, undertaken by researchers from the Indian Institute of Technology, provides the first-ever assessment of climate change impacts on the hydropower potential of 7 large hydropower projects in India. Each facility has an installed capacity of over 300 MW, and most are among the top 10 largest hydropower projects in the country.

The study found that all 7 reservoirs studied are projected to experience greater levels of overall rainfall by the end of the century, with some being up to 18% wetter than today. However, the increase in rainfall will not be evenly spread throughout the year. The authors expect that much of the increase will fall as heavy, monsoon rains. This means that the hydro-electric dams may have to withstand more severe flood events than have been previously experienced. It also means that streamflow will not increase throughout the year, meaning that the increased rainfall is unlikely to be matched by a similar increase in electricity generation potential.

The study also found that snow cover is likely to decline affecting several catchments of hydroelectric facilities. This decline in snow cover will mean reduce its contribution to streamflow in the winter season.

Other factors affect streamflow

Overall, the study found that that there would be an increase in streamflow for the 7 hydropower facilities, and that with good planning, India could increase its overall generation from hydropower. Planners should take account of climate-driven changes in streamflow to best capitalise on these changes.

To do this, it will be important to consider other factors, notably the changing demand for irrigation. Increased irrigation demand can have a significant effect on streamflow and reduce hydropower production capacity. If rain falls over shorter periods of time and in more intense bursts, the demand for irrigation in the longer dry periods is likely to rise. This could offset some of the potential increase in generation.

Other factors such as changing land-use patterns will also have significant impacts on India’s hydropower production capacity. However, it is clear from this study that climate change will have significant influence on the streamflow that reaches each facility. As streamflow is highly localised, and dependent of many contributing factors relating to local geography, assessments should be carried out on all current and proposed hydropower plants to assess how they will operate under various climate scenarios.

The study Projected Increase in Hydropower Production in India under Climate Change can be found here.


Kumar, A., Kumar, K., Kaushik, N., Sharma, S. & Mishra, S. Renewable energy in India: Current status and future potentials. Renew. Sustain. Energy Rev. 14, 2434–2442 (2010).

Cover photo by Thangaraj Kumaravel/Flickr (CC BY 2.0): Sharavathi hydroelectric power plant view.
Kerala floods kill hundreds & cause close to $3 billion in damages

Kerala floods kill hundreds & cause close to $3 billion in damages

By Elisa Jiménez Alonso

Floods in the Indian state of Kerala have killed over 320 people, caused at least $2.7 billion in damages, and displaced over 700,000. Authorities estimate that 20,000 homes have been destroyed, 40,000 hectares of farmland are under water and 83,000 km of roads have been damaged.

Between 8 and 15 August the state, which already receives a lot of rainfall, experienced over 250% more precipitation than normal. Water from 35 dangerously filled dams had to be released by state authorities, which in turn led to surges in rivers and overflowing banks.

While the rains have eased, poor sanitary conditions and widespread contamination of water could lead to the outbreak of several diseases, especially in relief camps where 724,000 people have taken refuge. The state requested $285 million in immediate assistance, however, Prime Minister Narendra Modi said the government would provide $71 million for immediate assistance and additional funds in the future.

Even though Kerala is one of India’s most prosperous states, the floods highlight how vulnerable South Asia is to climate change related altered rainfall patterns. Last year alone over 1,200 people died and an estimated 20 million were affected in some of the worst monsoon floods India, Nepal and Bangladesh have ever experienced. Megacities like Mumbai flood regularly leading to widespread infrastructural damage, death and disease, and leaving poor residents with even less than they had, increasing their vulnerability to adverse climate events or other risks and hazards.

As Kerala starts its recovery efforts, it will not just be important to build back but build back better, keeping in mind the shifting thresholds of a changing climate, but also putting a special emphasis on more vulnerable members of the population. As this year’s and past years’ extreme weather events have shown, India, and South Asia in general, are facing many challenges making the need for climate resilience more pronounced than ever.


To learn about measures that are already being taken in South Asia to adapt to climate change, head to the Action On Climate microsite and find out about the programme’s work to climate proof growth and development in India, Pakistan, Bangladesh, Nepal, and Afghanistan: http://www.acclimatise.uk.com/collaborations/action-on-climate-today/

Cover photo by Akbarali/Wikimedia Commons (CC BY-SA 3.0): Kerala flood – Cheruvannur mosque disappeared, 17 August 2018.