LIHU'E — A water rate increase is scheduled to take effect tomorrow on Kaua'i that will increase the average residential user's bill by about $6.50 per billing cycle, officials said.

The increase is based on a study conducted in 2005 on the Kaua'i County Department of Water's projected revenues and expenditures that recommended the implementation of a series of five annual 8.5-percent rate increases beginning in fiscal year 2006.

The water rate will increase from $2.65 to $2.90 per 1,000 gallons for the standard residential 5/8-inch meter within the first block (initial 20,000 gallon).

For the portion of the bi-monthly consumption that is between 20,000 and 40,000 gallons, the second block rate will be assessed. The increase in this category will be from $3.40 to $3.70 per 1,000 gallons.

The highest-volume residential consumers with usage of more than 40,000 gallons will pay a top rate of $5.40 per 1,000 gallons.

In addition, the monthly service charge for each customer account, general and agricultural, will also increase per month based on the meter size or its service capacity equivalence.

Although bill amounts will vary depending on individual usage, for a typical single-family residence with a bi-monthly usage of 25,000 gallons, the overall increase will be approximately $6.50 per billing cycle.

The water department implemented an inverted block rate structure for its general use rates and a block structure for agricultural-use rate consumption. These rate structures encourage water conservation as the rate increases will have a smaller impact on low-volume usage.

For more information on the water rate schedule, visit the Department of Water's Web site, www.kauaiwater.org. Click on Water Board, rules & regulations, and then click on Part IV - Fixing Rates for the Furnishing of Water Service.