But Eyewitness News has learned the number on your bill may not be accurate.
In fact, you may be conserving less than you think.
"I think it's a good gauge, but it's not 100 percent accurate," says Ed Buchan, Raleigh's Water Conservation Specialist.
Here's why: the city measures household water use in a unit called CCFs or cubic feet. Rather than recording an exact number of CCFs per billing cycle, the city chooses to round down to the nearest CCF for billing purposes. For example, if a household uses 5.9 CCFs in a billing cycle, you consumption will appear as only 5 CCFs on your bill.
To calculate total usage, the city multiplies your CCFs by 748, which gives you the total number of gallons used in a billing cycle. That figure is divided by the number of days in the billing cycle for an average water usage figure.
Here's a real-world example from a bill Eyewitness News obtained. According to the bill, the household used 7 CCFs between December 3, 2007 and February 4, 2008. The city multiplied 7 by 748 for a total of 5,236 gallons over that 2-month period. Dividing 5236 gallons by 63 days in the billing cycle, this household used 83 gallons per day over that period.
In truth, their usage could have been much higher. Because the city rounds down on CCFs, it's possible that household actually used 7.9 CCFs in that period. That would mean a usage of 7.9 times 748, or 5,909 gallons at an average of 94 gallons per day, 11 gallons higher than what the household bill indicates.
The city says it's working to get a system online in which CCFs will be recorded more accurately.
"It gives you a gauge as to sort of where you're at, and the goal is to try and get it down," Buchan says.
