16 Jul 2012

Zero footprint canoes

Editor's note: James Workman taught "Unlocking the Real Worth of Water" as a visiting professor at Wesleyan University last semester. He told his students that they -- like all people -- needed to be "water resource managers" because water allocations are increasingly driven by subjective individual values, not top-down planing. The students addressed these ideas from different perspectives (local utility, energy/water nexus, and water and food trade); each choose one essay to post here. Please tell them what they got right or wrong.

Glenn Hartman-Mattson writes...

A five-day canoe trip into the Boundary Waters of northeastern Minnesota has a carbon and water footprint of zero, right? You aren’t driving anywhere, you aren’t showering, there aren’t any light switches, no refrigeration, and no outlets anywhere. You are in a pure environment and really living deep green. You’re paddling down Moose Lake with the sun on your back; the only power you’re consuming is coming from your very own arms and core. Your usually guilt-stricken conscience takes a deep breath, “Ah yes. I’m not using a single drop of oil or municipally treated water right now.”

Alas, your conscience is mistaken. Even this trip consumes water and burns carbon. You’ve just discovered virtual water and the water-energy nexus.

Virtual water breaks down the production and transportation of an item into how much rain or river it took to create; the water-energy nexus helps reveal the power and carbon embedded in that water, and vice-versa. To produce a single apple it takes 70 liters of water. The water consumed to irrigate the apple orchard used energy to pump the water out of the ground. In turn, the pump’s electricity used energy to pump water out of the ground.

As you can see, water and energy are interconnected in an endless cycle throughout every sector, trade, and service. These two necessary commodities are mutually interdependent. To pump water out of aquifers a tremendous amount of energy must be used and to produce electricity a large volume of water is required. A thousand liters weigh a metric ton; lifting them up from even a shallow, 50-foot deep aquifer requires a tremendous amount of energy; to make the gas or electricity requires a large volume of water.

Four percent of all fresh water is consumed by energy production and three percent of electricity is used in the water sector. Electricity is second only to agriculture for productive use of water. Each day in the US 190 billion gallons of water is used just to produce electricity from fossil fuels and nuclear energy.

So how does this affect the carbon and water footprints of your canoe trip? One Wenonah Kevlar canoe: three sheets of Kevlar, high density structural foam, a whole lot of resin, low density foam, fiber glass, eight hours of vacuum sealing, aluminum gunnels and cross beams, rivets, nylon end caps and webbing, wooden seats and yoke.

All of these materials were produced and shipped to Winona, Minnesota where they were put together to form a light weight beautiful Wenonah canoe. Each substance and fabric took energy, and therefore, water to produce.

To boil this down, lets simply look at one component: transportation of the Kevlar alone. The 140-mile drive from the Du Pont Kevlar manufacturing plant in St. Croix Falls, Wisconsin to Wenonah head quarters in Winona, Minnesota burns 20 gallons of gas in a 7mpg semi truck. One gallon of gas requires 45 gallons of water to refine. For the Kevlar to travel from Du Pont to Wenonah takes 900 gallons of water. Now add the drive from Winona to Ely. Let’s say you are driving a LoveSubaru that gets 20mpg. The 330-mile drive will take 743 gallons of water. The grand total of water use to transport the Kevlar from St. Croix Falls to Ely is 1,643 gallons. Your once seemingly gasoline-free mode of transportation in the middle of Moose Lake is suddenly sopping in a mixture gasoline and water, literally and figuratively.

This is staggering, but useful. If you can acknowledge that even the most conservative day paddling a canoe is in reality full of water and energy consumption, then you can grasp how everything we eat, drive, charge, use, and buy has a shadow of energy and water behind its production. In a disposable economy, everything you consume and throw away, means you are also throwing away water and energy embedded within them.

And wastefulness of these precious commodities is the root of the problem. Wasted water is wasted energy; wasted energy is wasted water. We have an energy conscience, but this has not yet surfaced with water, which may very well be the pivotal catalyst to this century’s crises. As Nestle Chairman Peter Brabeck-Letmethe says, “… under present conditions and considering the way water is being currently managed, we will run out of water long before we run out of fuel.” Without water civilization cannot survive. Water is energy. Water is food. Water is life.

The synergy of the water and energy sectors would ensure the cooperation and conservation of both, delaying or avoiding a domino effect. Virtual water and the water energy nexus are everywhere, even, as it turns out, in the middle of nowhere. A Kevlar canoe may take 1,643 gallons of water to get to Ely, but that’s still less than the water embedded in a Big Mac or its Styrofoam container. So maybe a powerless and waterless canoe trip in the Boundary Waters points us in the right direction, letting us meditate in the kind of place that moves us to find a solution to this nexus.


  1. This kind of accounting needs to be specific about water use vs water consumption...the latter usually involves a phase change ie, lost to vapor, or pollution sufficient to make it unuseable. If the accounting is going to count water used to turn a turbine or pass through a heat exchanger, but then is released for other uses, it better include the water used to keep the canoe afloat too.

    also, I would hope the semi truck wasn't just hauling Kevlar sufficient for this one canoe....

    and, i would think the benefit of the canoe would extend well past this one trip during a 20? year useful life.

  2. This is well written and emotionally appealing, but not one of these issues is a problem that needs to be addressed or an awareness that needs to be raised IF water is priced correctly. Same goes for energy.

    The Nestle chairman should have said 'considering the way that water is being PRICED' not 'managed'.

    Pay full cost (including environmental costs) for the 1,643 gallons embedded in your canoe give your guilt-stricken conscience a rest.

  3. the issue i see is that the water footprint of your canoe or your apple has no objective value. water's value depends on the context of time and place. so if your apple was grown in a region of water abundance...then no big deal. if on the other hand, it were grown in a more arid region where the water had a bigger opportunity cost...then hopefully that water costed more and the apple costed more as a result

    alas, most of these footprint figures produce eye popping but context-lacking numbers...numbers that i'm not sure are actionable

    how to solve this: price energy dynamically- not by average cost. price water based on full cost. then let firms and users optimize their mix of production, adopt conservation measures, etc.


Read this first!

Make sure you copy your comment before submitting because sometimes the system will malfunction and you will lose your comment.

Spam will be deleted.

Comments on older posts must be approved (do not submit twice).

If you're having problems posting, email your comment to me