For many of us in South Africa who are fortunate enough to be able to employ people to work in our homes and gardens, saving electricity and water must be a cooperative effort. I have installed the dual-flush toilets, the low-flow shower head and the indigenous garden. But when the garden water taps and kitchen appliances are largely in the hands of people who don’t pay the utility bill, how can we fully control consumption?

Six months ago, I launched an experiment to address this conundrum, and I am happy to declare it a success.

First an anecdote to illustrate how far apart my gardener’s mindset was from mine. Last summer, when we went away for two weeks, I took a chance that good rains would continue and shut off the sprinkler system. (I always shut it off in the summer whenever we have had 25 mm of rain in the past week.) When I returned to Johannesburg, I was delighted to see the city looking lush and green; I knew that my gamble had paid off. As I arrived at my house, however, I was appalled to find my sprinklers spraying full-blast. The next time I saw my gardener, he cheerfully reported that the day I left he had discovered that I had left the sprinklers off “by mistake” and that he had “fixed it” for me.

So when he later borrowed a couple thousand rand to buy materials to build his mother a house, I knew how I could help him pay it back. I showed him my water bills from 2006, and told him that we would follow the 2007 water bills and compare them. As long as the garden remained reasonably green, we would share 50/50 any money we saved on water.

The first change I noticed was that he was using a broom to sweep a brick walkway that he used to hose down. When he washed the car, he used a big bucket, instead of a running hosepipe. And where I had often found him watering parts of the garden that didn’t need it, he now asks first.

My water bills for the last six months have come down by an average of 38 percent, and my gardener’s debt has been cut by R670. I know that some of this is because the garden is more established now and needs less water. The good rains in October also helped. But I am convinced that a major reason is that we both share the same mindset now when it comes to water conservation.

I still have control over the sprinkler system, so the garden won’t go brown, and I know that he is too proud to let plants wither. But I have a hunch that the next time I shut off the sprinklers for a holiday, he won’t be fixing my mistake.