An estimated 80 percent of Switzerland’s annual water supply will be “missing” by 2100, as glaciers in the Alps retreat under rising temperatures. A recent study by Swiss and Italian researchers addresses this anticipated loss by exploring whether dams could replicate the hydrological role of glaciers. Like glaciers, the dams would contain and store meltwaters at high elevations in the valleys where the glaciers once resided.
The authors, Daniel Farinotti of the Swiss Federal Institute for Forest, Snow and Landscape Research (WSL), Alberto Pistocchi of the European Commission’s Joint Research Centre (JRC) and Matthias Huss of the University of Fribourg, call the approach “replacing glaciers with dams.” Their method seeks to harvest the diminishing glaciers’ waters to maintain Europe’s water supply and contribute to power generation. .
The trio of authors are glaciologists and hydrologists, with expertise in chemistry, engineering, and resource management. Between them they have over 260 published works. Suffice it to say, they know what they are are talking about.
Speaking to GlacierHub, Pistocchi said that the idea occurred to him during one of his many cycling trips across the Alps. The possibility gripped him, and he began searching for colleagues in the field of glaciology to help him run scenarios on the future health of glaciers. He met with Huss, who had “recently investigated in depth the contribution of glaciers” to Alpine water resources. Farinotti was soon invited to provide an engineer’s perspective.
They studied how to “artificially sustain” the role of glaciers within the local hydrological cycle. The idea simply capitalizes on the natural processes already in motion. Meltwaters from glaciers naturally fill depressions, forming glacial lakes, or, if unimpeded, flowing into local rivers. Farinotti and his team were interested in determining how practical it would be to impound the runoff from melting glaciers with dams at the high elevations where the ice remains intact. They proposed that the glacier meltwater which accumulated would serve a similar role as the glacier had, as they would conserve the water and manage its release during drier seasons, thus maintaining a steady supply, and exploiting the newfound stores for power generation.
They found that while extensive melting will continue to provide meltwater from the European Alps in the near future, there are considerable logistical, financial, technical, diplomatic and bureaucratic hurdles to damming and storing it there.
Farinotti and his colleagues concluded that while their proposed strategy could preserve sufficient volumes to meet Europe’s water demands through 2100, the supply scheme is unavoidably “non-renewable.” The source glaciers’ volumes are finite, as is the quantity of water that could be dammed. Accordingly, without an additional strategy for replenishing the stores (i.e. pumping in Austria) in the high reaches of the Alps, the supply would eventually run out.
Between 1980-2009, glaciers supplied continental Europe with approximately 1,400 trillion gallons (5.28 km3) of freshwater per year — about 1 percent of the total volume consumed by the United States each year. The majority (75 percent) of the melt occurs (unsurprisingly) at the height of summer, from July through September.
Rivers flowing from the Alps received considerable contributions from the glaciers at this time every year. During the peak, six percent of the Rhine, 11 percent of the Po, 38 percent of the Inn, and 53 percent of the Rhône comprise glacial meltwater, according to Farinotti and his colleagues.
As many modelers do, Farinotti and his colleagues examined the impacts of a range of climate change scenarios on the Alps’ glaciers. They projected the probable volumes of meltwater, and health of glaciers in response to optimistic, realistic, and pessimistic concentrations of greenhouse gases (GHG).
They found that runoff from the European Alps’ 3,800 glaciers — which cover an area half the size of Glacier National Park — will increase over the next 23 years. However, the study finds that the summer meltwater contributions could decline by 15 percent mid-century. From 2070 to the end of the century, they project that the volume will decline by 29 percent in the best case scenario, but potentially up to 55 percent..
Farinotti, Pistocchi and Huss speculate that two-thirds of the decline in the water supply expected between 2070-2099 could be prevented, by “active water management,” such as their proposed method of damming the glaciers as or before they melt.
Farinotti’s team also see containing the source glaciers as means of overcoming some of the most common and controversial issues related to dam-building. From their perspective, their approach reduces the social and ecological tolls typically associated with dams, since people do not reside directly on the glaciers, and glaciated environments are hostile to most (but not all) plant and animal species. This method should avoid any need to “translocate”, or inundate thriving terrestrial biota, or disrupt river ecologies as elsewhere. Further, there should be next to no need to relocate any inhabitants, or for flooding historically or culturally significant sites.
However, a dam is a dam, and they all have their costs. Whether it be through sediment loading in rivers, increasing seismic activity, or influencing the region climate, dams are fraught with complications, as the World Bank elucidated in 2003.
In correspondence with GlacierHub, Farinotti and his colleagues acknowledged that the paper was not exhaustive and noted that “the strategy could alleviate one particular problem, but certainly not solve all challenges.” Other research on the development of lakes in vicinity of glaciers have indicated that Pistocchi’s approach may actually exacerbate the rate of melt.
That’s because the new presence of ponding water, which would have previously flowed down the mountain, would lower the reflectivity of the surfaces nearby the glaciers. This would result in the lakes absorbing the sun’s radiation, warming and likely accelerating ambient temperatures. Martin Beniston of the University of Fribourg alluded to the influence of glacial lakes on regional climate in 2001, in his paper “Climatic change in mountain regions: a review of possible impacts.” This would subsequently further promote glacier melt, as Jonathan Carrivick of the University of Leeds and Fiona Tweed of Staffordshire University also stated in 2006.
High altitude mountain glaciers, such as in the European Alps, are irrefutably disappearing at an alarming rate. Research led by Alex Gardner of Clark University found that between 2003-2009 approximately 259 gigatons of glacier ice was lost per year (excluding Greenland and Antarctic). That gargantuan loss in difficult to comprehend. But essentially it means that each and every year a quantity of ice greater than the total combined mass of 700,000 Empire States Buildings melts. Much of it ends up in the sea.
Farinotti, Pistocchi and Huss sought to “throw the stone in the pond,” (an Italian aphorism) the trio shared in correspondence with GlacierHub. They “wanted to animate the discussion about an idea that, apparently, has not been considered so far.” Radical approaches to adapting to the evolving threats of climate change are becoming increasingly necessary, though not always advisable.
This paper’s position is to err on the side of caution, and act preemptively to address the predicted water shortages that will plague Europe, while we still can. For the moment it seems a costly and impractical solution. But the same stance was adopted towards fracking when it first proposed. Today fracking provides at least half of America’s oil and gas. Will water become the “new oil”? Will our situation deteriorate to the point that damming glaciers becomes a viable solution?