Showing posts with label agriculture. Show all posts
Showing posts with label agriculture. Show all posts

Thursday, April 15, 2010

When Does Efficiency Not Lead To Conservation?

It is a hallmark of current thinking among conservationists that one of the greatest tools in our arsenal to promote the conservation of natural resources is increasing the efficiency of our use of those resources. The entirely logical line of reasoning being that if we get more bang for our buck, then we need less bucks – or water, coal, oil, electricity etc. This is a bedrock principle of modern water management. But recently I have been called on to look at “efficiency” a little more closely.

A couple of months ago I wrote a post about a recent report issued by the Pacific Water Institute on the great strides that can and have been made to increase the water efficiency of agriculture in California. In particular was one example I cited from the report of a farm that reported increasing its water efficiency by 20% (which can be found on p. 33 of the report).

I just received an extensive comment to the post asking about that particular 20% number. Wayne Bossert, manager of the Northwest Kansas Groundwater Management District No. 4, asked whether the 20% increase in efficiency represented a decrease in “consumptive use” or a decrease in water “diverted and applied.” Mr. Bossert explained the question as follows:

In any hydrologic system where the water supply and the water sink (where non-consumptive water uses go) are the same, increasing irrigation application efficiency just eliminates the sink supply and provides a higher percentage of the applied water to consumptive use crop production. You can pump less water with the higher efficient irrigation system, but you can also actually consume more water.

The 65% efficient irrigation system only makes 65% of the applied water available for crop production. The rest is non-consumptive use that returns (eventually) to the supply - at least in a traditional groundwater aquifer system. When a new 99%efficient drip system is installed, the producer pumps 75% of what he used to, but 99% of it is made available and consumed by crop production. My math tells me that 99% of 75% is more than 65% of 100%.

It is this extra water use that increases the yields so often reported when higher efficiency systems are converted to.
(Please read the rest of the comment here)

This comment struck me in two ways. First, I had always assumed that “efficiency” must be “good” in all circumstances – this comment has made me realize that “efficiency” is really a far more nuanced concept in water management. Second, as I have discussed in several different contexts, I believe that water management really needs to be looked at holistically, taking into consideration the entire hydrologic cycle. And that is exactly the point Mr. Bossert is making. In his example of the 65% efficient irrigation system, the other 35% of the water that does not go to the crops is not necessarily lost or destroyed. In fact, usually, that water simply returns to the natural hydrologic cycle. The same cycle that ultimately is the water supply.

To answer Mr. Bossert’s specific question, I have to say that the report doesn't provide a clear answer because as far as I can see it doesn’t squarely address the issue (though I admit I did not comb through all 75 pages). But my reading of it leads me to believe that the 20% increase in efficiency referred to a decrease in water “diverted and applied.” If the goal of water conservation is to reduce human use (i.e. consumption) of water, it seems we need to give greater thought to what it means to increase the efficiency of our water use.

This doesn’t mean that increased efficiency is a bad thing. Indeed, Mr. Bossert himself makes that point. And the Pacific Institute Report notes a number of non-consumption related environmental benefits associated with increasing irrigation efficiency. What it does mean is that increased efficiency may not be the ultimate solution for one of the largest water management challenges we face – dwindling supplies.

Wednesday, March 3, 2010

A Return To Blogging And A New Report From The Pacific Institute

After something of a hiatus do to work obligations, I’m back. And I think I should start off my return to regular (or at least more regular) posting with a positive story.

A new report has just been issued by the Pacific Water Institute, home to Peter Gleick, a much admired voice among those concerned with water related issues.

The eponymous subject of the report is “California Farm Water Success Stories,” and its purpose is to highlight examples of farmers in California who have made significant strides to increase the efficiency of their water usage. There is even a short video that accompanies the report that you can find here.

So why do you care? You care because agriculture is far and away the single most significant consumer of potable water in United States, and the world. As a result, any increases in agriculture’s water efficiency can have a dramatic effect on water supplies. Currently this is a critical issue in California and much of the southwestern United States.

The thrust of the report is that solving California’s water shortage requires increasing the efficiency with which Californians, and particularly farmers, use water. Moreover, increasing efficiency by a significant amount (one farm estimates it reduced its water consumption by 20%) is achievable with existing technology and at a cost equivalent to or less than that required to increase supply – and without the attendant negative environmental impacts.

It is an interesting report, and reinforces the fact that there are practical solutions to water scarcity that do not require us to sacrifice the environment.

Thursday, September 3, 2009

A “Complete Solution” to California’s Water Problem?

A group of Republican state Senators from California held a new conference wherein they stressed the importance of water to California’s economy and the need for “a complete solution to this complex problem.” (Thanks to Aquafornia for catching this.)

I applaud the sentiment. But I question whether their conviction is actually strong enough to take the kinds of steps necessary to create a “complete” long term solution.

There is less water today, and will likely be less water tomorrow, than the people of California have enjoyed in the past. But the problem is not really the “people” in the sense that we have a growing population. Rather the problem is agriculture. Both the types of livestock and crops we raise, and where we raise them. The Economist has an excellent article that discusses this issue which you can find here.

So…what does a “complete” long term solution look like for California? I see two roads we can go down.

In the first instance, we can look to government regulations to increase efficiencies in how we use water. But we’re not talking about low flow toilets or waterless urinals here. Long term water stability would require some serious regulations, particularly of the agricultural sector. This basically amounts to an end to agriculture as we know it. One can already imagine the howls from Republicans and other small government advocates – and they would have a point.

On the other hand we can commoditize water. Some economists, and the Economist, have suggested exactly that. Price water at its actual value and you will encourage farmers to grow crops appropriate to the local climate and water supply. But many people oppose commoditizing water for fear that the price increases will fall on personal water use and create enormous hardship for the poor. They have a point as well, though I think the greater danger of commoditizing water is the risk of speculation. Look here for an example of how commodity markets can be manipulated. And this too means an end to agriculture as we know it.

Neither solution is going to be popular with farmers.

In the end it comes down to a simple reality – less water. We can drain natural reserves like the Sacramento Delta. We can pump our underground aquifers dry. But while these activities may let us carry on, business as usual, for a few more years or even decades, they are ultimately self-defeating. We need those natural reserves and aquifers to keep the water cycle moving. Destroying them now for relatively short term gain only makes the ultimate accounting that much worse. An ultimate accounting that also means an end to agriculture as we know it.

So, do California’s politicians have the fortitude to really put together a “complete solution to this complex problem”? I sure hope so.

But I’m not holding my breath.