SYLVIE BELMOND/Acorn Newspapers ALL MAPPED OUT--Don Jensen, director of California Water Service Co. (CWSC) in T.O., shows what the new Harris Reservoir plans look like. CWSC is one of three firms serving Thousand Oaks. Alan and Rose Jeffery attended California Water Service's open house in Thousand Oaks last week to learn more about how water is delivered. They wanted to understand the treatment process and why the taste of water changes from time to time.

Rose is the president of the Westlake Island Homeowners Association. He's one of 7,400 customers in Thousand Oaks served by the California Water Service.

The water purveyor hosted the open house at its local headquarters to unveil a new reservoir project and to educate customers about the vital resource the company provides.

The new Harris Reservoir will replace the old one (south of Sunnyhill Street in North Ranch), according to Don Jensen, director of the local water company. The reservoir and pump station project could cost up to $10 million. Raw materials are expensive, he said, and a huge dam construction project in China has made concrete scarce.

In response to Rose Jeffery's concern about intermittent chlorine taste, Jensen said water agencies sometimes use a burst of chlorine to flush out bacteria in pipelines, but the levels are safe even when the smell is noticeable.

California Water is the smallest water purveyor in Thousand Oaks, serving residents in the Ventura County portion of Westlake and the North Ranch area.

The city has three water companies. About 18,600 people on the west end of town get their water from the California American Water Co. and the Thousand Oaks Municipal Water District serves the central part of the city.

California American Water, which serves customers in Newbury Park and some areas of Thousand Oaks, recently sent out notices that rates would increase by 10 percent if their rate hike request is approved by the California Power and Utility Commission.

It isn't the only water agency with plans to increase rates, said Mark Watkins, director of public works for the city of Thousand Oaks.

The city-operated water district has plans to raise water rates by 1.4 percent. The rate hike needs to be approved by the city council before it can take effect.

Unlike its two private counterparts, local public agencies don't have to go through the PUC for approval, Watkins said. "We go to the city council, and that's tougher because city officials are accountable to the local electorate."

The city's water agency is still the least expensive. Cal American customers currently pay 17 percent more for their water and California Water Service Co. customers pay 10 percent more, Watkins said.

The primary benefit of having a city water purveyor is that government entities don't make profits and services are all localized, Watkins said. "That reflects in the customer service and the quality of water."

Since water services are linked to other fundamental city services, it makes sense that the water purveyor is a public agency, Watkins said, although he indicated that competition can be a healthy thing. "It keeps us on our toes."

Thousand Oaks residents are served by three water purveyors because of how the city was developed, Watkins explained.

When the Village Water Co., formed by the Janss Co. in the 1950s and '60s, was for sale, the city wanted to buy it, but Village Water sold it to Cal American.

"Basically everything west of Moorpark Road is served by that company," Watkins said.

The city handles all wastewaters for Thousand Oaks and Newbury Park at the Hill Canyon treatment plant, while the Triunfo Sanitation District serves the Westlake region because that water drains into another watershed, Watkins said.

Single residences pay a flat rate of about $25 per month for sewer services.

Private water companies do have boundaries. Although they have investors, they have limits on how much they can earn in profits, Jensen said.

All the local water suppliers obtain their water from the Calleguas Municipal Water District. The wholesale distributor sells water to 22 companies serving about 75 percent of Ventura County.

Rates are increasing because energy costs are rising and state laws are enacting more regulations to ensure that water is safe, according to water officials.

"All water companies use similar pathways, but they function differently in terms of efficiency," Jensen said.

Cal Water, being the largest utility company west of the Rockies, is a big outfit, so they get a better deal on some equipment purchases, he said. "But we don't get breaks on water."

At the open house, residents also wanted to know whether they should drink tap or bottled water. Jensen said he'd rather drink out of the tap than a bottle of Perrier.

Tap water costs about $2 per 100 cubic feet (748 gallons), while people pay from $1 to $4 a gallon for bottled water, which is not as regulated, he said.

Local water purveyors aren't concerned about the bottled competition. Eighty percent of the water sold by local water companies is used on landscaping, not inside the home, they said.