Nepal, May 2 -- he holy Bagmati River is in the news this week because of the eviction of settlements along its banks, but that alone will not revive the river and its tributaries that are ancient symbols of the Kathmandu Valley civilisation.

I have stood at Pashupati and watched the Bagmati flow past, a river that looks like it is not alive anymore. The stench is overpowering and stays with you long after.

Priests were performing funerary rituals right next to where sewers entered the river. Devotees cup that same water in their hands. I was a student then, and did not fully understand what was happening.

Things have improved somewhat, but the broad free-flowing Bagmati is still essentially a channeled sewer. Now, years later, resear...