Hundreds of Oxnard children will leave their old, portable classrooms next year and move into new, permanent buildings at their schools.

Construction crews have started moving dirt at both Curren and Kamala schools in the Oxnard School District. Each of the elementary schools is getting a new 22-classroom building, both scheduled to be finished next summer.

The additions will allow the schools to get rid of more than a dozen portable classrooms scattered throughout the campuses.

"This building is going to make a big difference," Superintendent Rick Miller told a crowd of students and staff at Curren School on Tuesday, the first of two official groundbreakings held this week.

A green fence separated the construction site from the stage where he stood. Students at the year-round school could see tractors moving mounds of dirt behind him.

"We're here because of you," school board member Arthur Joe Lopez told them. "We're making it better for you."

The new buildings also are expected to allow the schools to abandon their year-round, multitrack calendars.

In the multitrack system, groups of students have staggered vacation schedules. That way, the district can teach four groups over the course of a year using only three classrooms.

But students and teachers lose days of quality instruction time every time they have to pack up for vacation and move into a different classroom, and district officials are working to bring all schools to a single-track calendar.

Kamala Principal Mary Mackenzie said the new building will give students a sense of pride in their school, and the switch to a single-track schedule will make a difference in student achievement. Kamala had its groundbreaking Wednesday.

"We are very excited," she said.

The district bid the work at both K-6 schools in one construction contract, allowing the work to proceed simultaneously.

The projects combined will cost the district about $25 million, which will be paid using proceeds from a $64 million bond issue and a yet-undetermined amount of state funding.

District officials have been planning the buildings since 2002, but money was an obstacle until voters passed the bond measure in November.

The money also is expected to pay for a new school capable of housing some 700 students, as well as new buildings at Driffill and McKinna schools.