Is Nepal's flood a harbinger of what's to come in the Himalayas?

The Nepali Army conducts a search-and-rescue operation on Sept. 10 inside the Chilime Hydropower Station tunnel days after the deadly flash floods and mudslides in Nepal's Rasuwa district in August. In the wake of the disaster, concerns are being raised about the impact of the construction of hydropower plants and dams in the Himalayas. Skanda Gautam/AFP/via Getty Images hide caption

KATHMANDU, Nepal — On a recent September day, Sumana Shrestha Amatya stood alongside other protesters in the Nepali capital, urging the government to work faster to find their loved ones, trapped inside hydropower plants since flash floods devastated miles of a river valley in late August.

Amatya says she hasn't heard from officials about her husband, Sunil, a geologist. Still, she acknowledged the scale of the disaster that the government was grappling with: "It was like a Himalayan tsunami."

It's a description other Nepalis have used for the events of Aug. 26, when a glacier and its bedrock spanning more than 3,800 feet in width collapsed into a river valley, some 4,000 feet below.

That triggered 30-foot-high waves of boulders, water and ice that surged for miles downstream. It swept away a multistory border building and some 70 bridges and miles of highway, and buried 12 hydropower plants under mud and boulders along the Trishuli River, which was badly impacted by the floods.

Some 1,400 bodies have been recovered in Nepal , and more than 5,000 remain unaccounted for.

The dead and missing include 121 people who were trapped in hydropower plants, according to Brig. Gen. Subas Jung Thapa of the Nepali army, which is leading rescue efforts. He spoke in early September.

It took days just to find the power plants under the mud. It was like "a bomb's gone off," said Arnold Dix , a tunneling expert helping with rescue efforts. "It's removed the power stations from the surface, like they're just not there." Only three men were found alive in the plants since rescue efforts began.