The case for hydropower
The agricultural sector benefits a lot since it doesn’t have to depend on the rainy seasons to sow the crops.
Dams are free from pollution, provide clean energy and although they are a great source of cheap electricity and water supply, they are not free from controversies associated with environmental and negative social and cultural impacts.
Big concerns have been raised with regard to the displacement of human, animal and plant life, erosion of land and sedimentation issues. We study the benefits and potential hazards of hydropower by analyzing one dam, namely the Three Gorges Dam built in China, which too became a center of controversy.
The three gorges dam was built on river Yangtze in China. It is the world’s largest gravity dam. Its power plant housing 32 turbines generating a total electric power of 22,500 MW was commissioned in 2012.
It has a reservoir 600 km long with a maximum storage capacity of 39 billion cubic meter.Thus saving the planet from the deadly effects of massive greenhouse toxic gasses. The dam can successfully minimize the effects of even a major flood.
In 2009 a major flood passed through the dam site. The dam successfully controlled the flood by limiting the flow of water downstream.
Besides, the dam discharged enough water into river downstream during the dry season to supply fresh water for agriculture, industry and urban usage.
The clean energy produced by the Three Gorges Hydroelectric Power Station in 2020 is estimated to be equivalent to saving about 34.39 million tonnes of standard coal and preventing the emissions of carbon dioxide by 94.02 million tonnes.
The downside of the dam was relocation of 1.3 million people and settling them in new habitats.
The catchment area of the reservoir erased many cities, towns, villages and archaeological sites. The habitat of the birds and the wild animals was destroyed. Some other issues like the effects of sedimentation and erosion were also raised.
However the upside of the dam far outweighs the downside if we consider the successful evacuation and rehabilitation of the human, animal life and plant life at much improved habitat. The Chinese government therefore termed it rightly a great economic and social success.
Pakistan is one country badly affected by the onslaught of floods. This year, the unprecedented rains and the glacial melt inundated the country with floods of epic dimension. All the valuable and staple crops have been obliterated.
This time the flood has rendered one third of the country underwater causing a death of around 1500 people while almost 33 million got displaced. Overall damage is estimated to be “far greater” than $10 billion.
One dam which could have saved the country from such a castrophy could have been the Kalabagh Dam. But it became a victim of irrational doubts and hypothetical fears.
We encounter floods almost every year, some high some low, especially in the Sindh province with corresponding damages. There is no immediate respite in sight.
The decision makers have other priorities than even considering building the dams to tame the floods. Till the time some solution is envisaged and implemented, people will have to live on the mercy of nature.
Hydropower offers the cheapest and the cleanest energy. It offers a sustainable supply of power as like in the case of solar or wind, it does not depend on the intermittent availability of sun or wind which are dependent on weather.
We almost get a continuous supply of energy year round with the exception of a month or two. It frees us from dependence on imported fuels needed to run thermal power plants. The socio-economic benefits of dams are therefore much higher than the negative environmental and social aspects.—Concluded.
—The writer is an Engineer, based in Islamabad.