In the popular imagination, there is only one threat to picturesque mountain landscapes that can compete with the destruction wrought by flood disasters like the torrent that swept through valleys on the Nepalese-Chinese border: dams.
These concrete behemoths replace occasional catastrophic natural inundation with one that is permanent and artificial. Pristine river valleys disappear beneath reservoirs. Communities are forcibly relocated, their lives uprooted.
Those criticisms are true. But the events of the past week, with 955 dead and more than 4,000 still missing, should be a warning that the imagined counterfactual is false. Roads, tourism, trade and settlement are already transforming remote mountain communities.
Meanwhile, warming is destabilizing the very soil on which homes are built and sparking disastrous floods. The question is whether development will include the infrastructure needed to manage increasingly volatile rivers.
The damage caused by some large dam projects is real. India’s efforts to build a string of reservoirs on the Narmada River displaced hundreds of thousands of poor, tribal and low-caste families. That injustice sparked a movement that helped give hydro such a bad name that development banks largely stopped funding it in the 1990s.
In retrospect, this was a terrible outcome. Hydroelectricity is one of the few forms of generation to match the rock-bottom prices of wind and solar. When it is built with a storage reservoir, it also provides on-demand, zero-carbon electricity that can be stored from one month to the next. Such dams can also help control floodwaters that could do grievous damage to downstream communities.
A potent example happened in 2018 on the other side of the Tibetan plateau. After a landslide blocked part of the upper Yangtze River and formed a vast unstable lake, dam managers at six reservoirs downstream proactively dumped 1.3 billion cubic metres of water so they would have enough capacity to absorb an outburst flood.
Along with other measures, that appears to have substantially reduced the damage done. Storage dams in Austrian river valleys in recent decades have reduced extreme water levels by about a third relative to their previous peaks, as per a 2022 study.
The withdrawal of funding from aid donors didn’t stop hydro being built. With the World Bank sitting on the sidelines in the 1990s, China self-financed the Three Gorges Dam, the world’s biggest power station. Africa’s largest, the Grand Ethiopian Renaissance Dam, was also largely paid for out of Ethiopia’s meagre domestic budget amid objections from neighbours. Tanzania is now doing the same.
Nepal itself is going through a mini-boom, driven by private developers building run-of-river generators—a sort of water-wheel on a massive scale that cannot store significant volumes. About 90% of hydro in Nepal is this type, which provides little of the on-demand power or flood-control benefits of storage dams. The workers missing or rescued from flooded construction tunnels after last week’s disaster were all building run-of-river plants.
The funding drought from multilateral donors has been persistent. Back in 2004, the World Bank argued the pendulum had swung too far against hydro and vowed to reverse this trend. Despite that, the sector has not benefited from a spending surge on renewable energy since.
Commitments for hydro comprised just 2.8% of energy funding by major development banks in 2022, the lowest share since 2009. Since the 2015 Paris Agreement, they have promised $8.7 billion. Even fossil-fuel production and generation have done better, at about $12 billion.
That’s a perverse outcome. Hydro is likely being crowded out by more bankable solar, wind and battery plants, but the point of development banks is to finance projects that don’t pencil out well in raw cashflow terms. It’s hard to put a dollar value on the lives and livelihoods saved if a once-in-a-century flood can be prevented by the sort of water engineering rich nations take for granted. The benefits are nonetheless real.
Nepal’s vast natural water resources and relatively small population should allow it to earn good money selling electrons to its energy-hungry neighbours. Yet, until 2023, it was importing more power from India than it was exporting. A transmission line to Bangladesh only went into operation last year. Even amid the current building boom, it has completed just 3.4GW of the 42GW of hydro capacity that’s economically viable, with another 4.3GW under construction.
Will the next generation of hydro projects merely extract electricity with run-of-river dams? Or build storage dams that give downstream communities greater protection from the consequences of our increasingly deadly climate? ©Bloomberg
The author is a Bloomberg Opinion columnist covering climate change and energy.