Conservation Corner: Why one water conservation project backfired

Conservation corner - fall 2008

Give me a hammer, a nail, and a 2”x 4” piece of board and I guarantee the result will be a broken thumb. I am ashamed to admit it, but since I was never interested in building things with my hands, I never learned how to use even the most basic tools.

Having the right tool without the knowledge and willingness to use it correctly is as useless as having the knowledge and willingness, but not the tool. You need all three to get the job done. The following story illustrates what I mean.

In August 2003, a firestorm swept through Okanagan Mountain Park. The fire consumed two Kelowna neighbourhoods, destroying 239 homes. Out of the ashes came the will to rebuild, and environmental educators in Kelowna saw an opportunity to promote environmentally sustainable construction.

We held seminars for people who lost their homes; 150 people showed up to hear about the latest concepts in energy reduction, waste reduction, and water conservation. Landscape and irrigation experts spoke about Xeriscaping and efficient irrigation systems.

Over the next few years, it appeared that many homeowners took our advice. While it is difficult to give an exact number, I estimate about 15% of the rebuilt homes had extensive Xeriscaping in the front and back yards, where turf and cedar hedges had been the norm. I counted this as a success.

Flash forward to 2008, when I tried to quantify the water savings at the homes where the greatest conversion to Xeriscaping took place. I chose 12 of these homes at random and compared their pre- and post-fire water consumption. I

f this is where you expect me to say that the 12 homes cut their water consumption dramatically after converting to Xeriscape, you are wrong. Of the 12 homes, seven actually use more water for irrigation now than they did when they had turf and   cedars, two use about the same, and only three use less.

What happened? It turns out that increases in water consumption after Xeriscape conversion is not unprecedented. When the City of Albuquerque offered residents money to replace turf with Xeriscape plants, 17% of the participants ended up using more water after the conversion. An Arizona State University study found that some
Xeriscapes in Phoenix received at least 10% more water than traditional turf grass landscapes.

A 1994 Xeriscape study in Texas concluded, “The main cause for excessive landscape water use in most situations is the human factor; the waste of water results from improper irrigation practices… rather than any one major group of plant materials.”

This comment is echoed by the past president of the National Xeriscape Council in the United States who said: “The type of plant materials or irrigation system in the landscape has much less effect on water consumption than the human factor of good landscape water management.”

I speculate that the Kelowna homeowners who converted to Xeriscape after the fire did not have the knowledge to do it, so they hired a landscaper. In hindsight, I should have followed up the original seminars with education directed to those homeowners who made the decision to convert to Xeriscape. Those homeowners who did save water likely planted their own Xeriscapes, and, therefore, had a vested interest in using less water.

Xeriscape is simply a water conservation tool. The homeowner still has to learn how to irrigate for water efficiency. This experience (along with my knack for hitting my thumb rather than the nail) demonstrates that using a tool without the knowledge and willingness to use it properly can actually be counterproductive.


By Neal Klassen, BCWWA “Watermark” contributor


Posted October  2008


Originally published in the Fall 2008 issue of Watermark Magazine, the official publication of the British Columbia Water & Waste Association (BCWWA).