Wednesday, April 28, 2010

Ice Dams

No, not the kind you're thinking of.

I'm talking about glaciers. Glaciers act as natural reservoirs for most of the world's population. Melt water is what keeps the rivers running during the summer. Unlike traditional reservoirs, however, they don't interfere with river navigation, fish migration routes, or drown shoreline habitat. And they're less prone to evaporation, which is a big cause of water loss from a reservoir.

We need to create glacial reservoirs by creating ice dams. Unlike a traditional dam, the purpose of these ice dams would be to slow the rate at which the glacier descends the mountain to lower altitudes. The best illustration of how this would work is to look at a slide in wintertime. The steps up to the slide hold a lot more snow than the slide itself does. What is on the slide, as the name implies, slides off. What is on the steps stays put. Instead of a vertical dam to hold back water, we'd build horizontal dams to hold back ice. In the illustration below, the rectangles are glaciers, the blocks represent a series of dams, and the blue triangles represent the increased water storage:

We'd still need traditional reservoirs, of course, to meet short-term fluctuations in the water supply (it's hard to tap ice, after all). This means of storage would help us meet a long-term, multi-year drought.

Another use of this arrangement is that you could create glaciers in mountain valleys that don't normally support them. Rather than having a spring flood from those valleys, you could moderate the flood and store some of that water for later use, particularly since, by keeping it at higher altitudes, it would be more likely to freeze overnight, thus releasing the water slowly.

Don't fight nature. Just make it more efficient.

2 Comments:

OpenID bruce-church said...

Or just create huge underground artificial reservoirs like mines. That way there's no evaporation, and you can stick a dipstick into it to see how full it is.

11:13 PM  
Blogger Octavo Dia said...

Cisterns are already in use all around the world, and have their uses and drawbacks as well. We'll still need them for short-term water storage for human use. This is more of a long-term, ecological storage device.

7:11 PM  

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