LATHROP — A pent-up demand for charter schools means the South County’s newest public elementary campus - River Islands Technology Academy - will open in August with a waiting list of students trying to get into kindergarten through fourth grade classes.

 Work is still being done on the $25 million campus being built as part of the planned community of 10,800 homes known as River Islands at Lathrop.

“We were surprised,” said Susan Dell’Osso, River Islands project manager and school board member. “There was standing room only at the orientations we held.”

Altogether 550 have applied so far for classes that start in August.

The academy already has all space in the kindergarten through fourth grades filled with 150 students on a waiting list. There is still space in the fifth and sixth grade classes. The academy is currently taking applicants for the fifth and sixth grade as well as the kindergarten through fourth waiting list at www.riverislandsacademy.net

River Islands will add a seventh grade class in the 2014-15 school year and an eighth grade class in the 2015-16 school year.

The charter school is not filling all available classroom slots. That’s so when homes start selling in River Islands, elementary students from those households can be accommodated. Home construction is expected to start by fall.

High school students in River Islands will attend Tracy Union High School campuses.

The bulk of the new students are coming from Manteca Unified School District campuses in Lathrop with the largest number of those from the nearby Mossdale neighborhood just across the San Joaquin River.

The academy has accepted applications from communities throughout the region.

Younger students will receive tablets instead of standard textbooks while older elementary students will use Chromebooks.

Charter schools have been growing in popularity in California since the mid-1990s.

Ten years ago only about 2 percent of students whose K-12 education was funded with California tax dollars attended charter schools. Today, it is 7.8 percent and would be at 8.9 percent currently if there were enough charter schools.

The state Department of Education reports there are 70,000 students on charter school waiting lists with 484,000 actually enrolled in California charter schools.