Wichita water rates are about average for households using modest amounts of water. But households using a lot of water pay much less than average, leading us to wonder if Wichita could adjust its rates to encourage conservation and/or generate more revenue.
Data from a 2012 Black & Veatch survey of water and sewer rates in 50 large cities reveals an interesting characteristic of water rates.
Many cities have tiered water rates, where as a household uses more water, the marginal cost per gallon rises. This is the case in Wichita. Each household has its average winter consumption (AWC) as measured during the winter months. Presumably this is the water that is used for cooking, cleaning, flushing, bathing, and other indoor household needs. For Wichita city customers, for usage up to 110 percent of this value, or AWC, the rate is $1.77 per thousand gallons. For water used from 111 percent to 310 percent of AWC, the rate is $6.25 per thousand gallons. For use over this level, the rate is $9.13 per thousand gallons.
This means that water used inside the house — the presumed basis of AWC — has a low price in both winter and other seasons. But water used much above that value is more expensive. This is probably water used for swimming pools, irrigation of lawns, and other outside summer uses.
(The water usage is not the only cost that appears on Wichitans’ water bills. There is a minimum monthly charge and a charge for sewer service, and others.)
Back to the Black & Veatch survey. For the 50 cities in the survey, considering only the water portion of bills, the average cost for using 3,750 gallons per month is $19. For using 15,000 gallons, the cost is $65. That’s a ratio of 3.4 to 1.
For Wichita, the survey reported costs of $18 and $36, for a ratio of 2.0 to 1.
These are two important numbers: 3.4 and 2.0. They mean that while Wichita water becomes marginally more expensive as more is used, the slope is not nearly as steep as the average. It means that households that use low amounts of water pay about average rates, but those using a lot of water pay rates much less than average.
Does this mean that if Wichita is serious about conservation of water, that it could ramp up summer water rates more in like with other cities? It looks that way.
And would this provide the revenue the city says it needs to develop a new water supply?