Saving this much water is, of course, a good thing for the environment, but you may also save a lot of money on your water bill. Water rates vary by municipality, but we can estimate the possible savings by looking at the water rates in California at the time of this writing.

Water costs about $1.5 per 1,000 gallons in California, and sewage costs $4.26 per 1,000 gallons, for a total of $5.76 per 1,000 gallons of water that comes out of the faucet. That indicates that providing one inch of water to a 100′ x 100′ yard costs more than $12.00 if you have a separate irrigation meter, and $39.00 if you don’t. Watering your lawn once a week throughout the summer will cost you close to $50, or $156 every month. This means you will end up saving more than $18,000 every year.