Kathmandu Valley’s rivers have always been in full spate during the monsoon, but their wide floodplains allowed the water to spread while fertilising the banks with nutrients.
But in a process that accelerated after the multiparty system was restored in 1990, and especially since the Maoist conflict began in 1996, the Valley’s population exploded. The real estate mafia and their political partners gradually encroached on the riverine flats.
Some of the tributary streams of the Bagmati now have roads and houses built over them, others have been squeezed into narrow canals. With just 90mm of rain in 24 hours, these waterways easily overflowed this week, submerging the banks.
“It was not a lot of rain, but it fell over a short period and there was nowhere for the river to go,” watershed expert Madhukar Upadhyay explained to us.
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Rainfall patterns have changed with frequent torrential microbursts or prolonged drought due to climate change, but the main reason is that we have constricted the rivers and streams.
“This should be taken as a warning,” Upadhyay added. “This week’s floods could have been as bad as they were in Uttarakhand or Beijing if rainfall was heavier. We should have had strict zoning laws about not building along floodplains.”
Kathmandu’s urban heat island effect meant that this year’s pre-monsoon maximum was up to 5°C higher than average. Trees that would have cooled things down are gone, concrete and asphalt trap the heat.
In winter, the Valley’s air quality is unbreathable and off the charts. Inability to control vehicular fumes, garbage burning and brick kiln emissions means suspended particles are trapped under an inversion layer. The city has now given up trying to control vehicle emissions, and subcontracted it to the private sector.
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Emissions can be curbed with a systematic push towards electric public transport and battery-powered vehicles. This would also mean using surplus clean hydroelectricity that is going to waste. Instead, the government has increased taxes on electric vans.

