5.5% Water Rate Hike Approved : Utilities: Two-thirds of Ventura County residents will be affected by the increase, which takes effect in July.

A 5.5% rate hike that will boost the cost of water from Simi Valley to Oxnard was approved Wednesday night by the wholesaler that provides water to two-thirds of Ventura County residents.

The board of the Calleguas Municipal Water District agreed to up its rates to cover the cost of an increase imposed last month by its supplier, the Metropolitan Water District of Southern California.

The rate increase will affect nearly 500,000 residents and commercial customers in Simi Valley, Thousand Oaks, Moorpark, Camarillo and parts of Oxnard.

If the companies that buy water from Calleguas pass the increase directly on to their customers, a typical four-person household that pays about $390 a year for about 163,000 gallons of water will see that cost creep up to about $411. The new rates will go into effect in July.

Unlike past across-the-board rate hikes, however, Calleguas officials have decided to base the increase on the amount of water used by each of the agencies that buy from the district.

So instead of levying a per-unit increase for water at the time it is purchased, Calleguas has calculated a flat annual fee each member agency will pay based on how much water they have used in each of the past three years.

The money collected from the fee will go directly toward Calleguas’ $2.5-million annual debt service. Calleguas’ action follows a recent MWD decision to phase in a similar change over the next several years.

For bill-paying residents and businesses, the change in how the increase is levied may not lessen the effect of the rate increase.

But Calleguas General Manager Don Kendall said the new approach could help stabilize the cost of water when a similar rate plan by MWD takes effect.

“Rather than looking at increasing rates every year, we’ve decided to try this fixed fee,� Kendall said. “Knowing that we have this guaranteed, fixed amount of money coming in could help us keep the cost to our customers the same over the next several years.�

Calleguas began pursuing the new rate structure last fall after customers complained about the district’s rates and MWD’s annual price hikes. After keeping its rates flat for five years, Metropolitan levied increases of 13% in 1991, 23% in 1992, and 19% in 1993.

Critics charged that the MWD increases unfairly saddled Ventura County customers with the cost of water projects in other parts of Southern California, including a $1.5-billion reservoir in Riverside County.

“When they’re passing through something from MWD there’s nothing we can do about it,� Simi Valley Mayor Greg Stratton said. “But they always seem to add a little extra.�

But Kendall denied the charge, saying Calleguas merely passed MWD’s increases on to the customers.

“All we’re trying to do is control water rates and cover our costs,� Kendall said.