“Water, water, every where, nor any drop to drink.” Taken from The Rime of The Ancient Mariner by Samuel Taylor Coleridge, surely everyone’s heard one form or another of this old verse. Looking at this recent picture of the Bitterroot River outside of Hamilton Montana, and with many of the rivers in Montana running near or over flood stage, it’s hard to imagine that we could ever be in a position with out enough water for all of our needs.
In fact, looking at the earth itself and the incredible amount of water we see, someone might wonder why we even care about conserving water and place so much weight to it when talking about green building today.
The fact is that even though over 70% of the earths’ surface is covered by water, 97.5% of it is salt water, leaving only 2.5% as fresh water. Further, of the remaining fresh water, over 70% of it is locked in icecaps, more is located deep within the earth in unreachable aquifers and even more is in the form of soil moisture, leaving only what amounts to having less than 1% of all the earths’ fresh water available for direct human uses.
The amount of usable fresh water, the stuff found in lakes, rivers, reservoirs and the aquifers that are shallow enough to be effectively tapped into, makes up less than .007% of all the water on earth. It’s hard to really understand how little that is, but if you think of all the water available on the planet in a full 55 gallon drum, the amount that we can access for use is less than three teaspoons full. This is the only water that we have available on a sustainable basis that is regularly renewed and regenerated by rain and snowfall, and this amount will not increase.
Considering this, it’s easy to see why one of the key guiding principles in green building focuses on conserving the water we have and protecting it from runoff, sedimentation and all other contaminants. If we don’t, the fight over those last three teaspoons could be devastating, and the words from the old mariner in the tale will ring true for us all.
