Tsho Rolpa, a glacial lake at the head of Rolwaling Valley
Tsho Rolpa, a glacial lake at the head of Rolwaling Valley Chronology of Tsho Rolpa GLOF Hazard Response |
Tsho Rolpa is a lake that has been growing rapidly in the upper Rolwaling valley, fed by increasing glacial melt. It is held back by lateral and terminal moraines that are naturally porous and unstable. Typically, the instability of such lakes is resolved by a "glacial lake outburst flood"; once the banks are breached or over-topped even slightly, the entire wall tends to give way quite rapidly. At this point, there is little question that, absent human interference, Tsho Rolpa would naturally burst forth, sooner rather than later, with considerable damage to the communities clustered along the Rolwaling valley floor, and also further downstream. Threatened infrastructure includes a large power station at Khimti, 75 km downstream.
The Tsho Rolpa problem first came to Seth Sicroff's attention in September, 1992, when he was trying to organize a "Center for the Study of Mountain Tourism" at the University of California, Davis. One of the hundreds of responses to his needs assessment survey came from Roger Henke, then manager of operations at Summit Nepal Trekking. Henke's letter included the following remark:
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The only item of your database list of considerable interest to us would be the annotated bibliography; we are involved in a joint project with the Sherpa community of Rolwaling to save their valley from being washed away by a GLOF of Tso Rolpa (the largest glacial lake in Nepal) and of opening it up to ecologically sound trekking tourism actually staying in the valley instead of only using her as a conduit to the uninhabited heights of surrounding Himals... Any input on how to go about the second aspect, from wherever it comes, is appreciated. |
At the time, Sicroff's advisor at the University of California at Davis was Jack D. Ives, who had written the most extensive study of such phenomena in an "occasional paper" published by the International Centre for Integrated Mountain Development (ICIMOD) in 1986: Glacial lake outburst floods and risk engineering in the Himalaya. In addition to Ives, Sicroff sought help from Robert Schuster of the US Geological Survey, who provided bibliographical leads, and passed these on to Henke, along with a suggestion for stupa project. (Sicroff's idea was to lay out plans for a huge stupa overlooking -- a guarding against -- Tsho Rolpa; the stupa would be constructed stone by stone by tourists, who would make a donation to the local monastery in exchange for guidance in the placement of stones, and in order to fund local development projects. In this way, the potential disaster would become a tourist attraction and the source of funds to mitigate it.)
In 1998, when Empar Alos Alabajos and Sicroff were looking for a site to undertake both tourism research and also some kind of engineering project, Rolwaling and its precarious lake came to mind, and they selected it -- as well as Roger Henke's goal of longer-term tourism -- as the site and the rationale for the Bridges pilot program.