Annual rainfall here in San Jose, California, is about 15", distributed fairly evenly. I can't tell from my water bill what percentage of water use (and expense) is for household use versus landscaping, but my son's science project says a California family of four like ours uses a whopping 174,000 gallons per year! Our typical mixed landscaping covers about 3500 square feet. What percentage of my water utility costs and usage might be for landscaping?
Roger M. ~ San Jose, California
Roger, thanks for the question, and I'm sure plenty of our other readers are wondering how much money they spend each year to keep their landscaping watered. Well, the EPA estimates that as much as 1/3 of all the water consumed by U.S. households is used for landscape irrigation. So if your family is consuming 174,000 gallons of water per year, then as much as 58,000 gallons of water could be going towards keeping your grass green and your flowers blooming!
If you want to calculate the utility costs of your landscape water usage, then you will need to install a second water meter at your home which measures only the water which is used for irrigation. In my area, many households meter their irrigation water separately from their household water, because the utility company calculates a monthly sewer bill based on the amount of water which is used inside a home. Obviously, irrigation water does not wind up in the sewer system, so that water usage is metered separately and does not effect the monthly sewer bill.
If you want to lower your monthly water usage, then you should consider installing low-flow drip irrigation lines, which use much less water than surface area sprinklers. Another helpful way to conserve water is to only irrigate your landscaping a few times per week and never when it is raining. Over-watering your grass not only wastes water, but it also forces you to mow your lawn more often! Even during your hot California summers, there should be several ways to reduce your water usage and still keep your landscaping looking healthy and growing strong. Good luck with it!