Manteca Unified School District’s competition was fairly small just a few years ago.

Primarily Christian schools such as St. Anthony’s, Plumfield Academy, Ripon Christian Schools, and Manteca Christian Schools competed with the district for students. And given parents had to come up with the tuition, the numbers of students who opted out of public school was small.

Now the school landscape has changed. The Christian schools have been joined by public charter schools in and around Manteca - Great Valley Academy, Ripon Unified Virtual Academy and a variety of charter schools through the San Joaquin County Office of Education. Manteca Unified even has its own vocational charter school - a culinary institute - aimed at a bit of a different target of high school students interested in securing a marketable skill upon graduation. And now there are two more charter school options for this fall - the Escalon Unified School District’s Escalon Charter Academy at all three of the district’s elementary campuses and the River Islands Technology Academy in Lathrop.

River Islands - which is starting with 350 students in its initial year and eventually expanding to about 700 - appears to have its biggest interest coming from families of students already enrolled in Manteca Unified elementary schools in Lathrop.

The money paying for students enrolled in charter schools is simply diverted from the local school district they would have attended.

“It hasn’t had a negative impact on Manteca Unified,” noted Jacqui Breitenbucher who serves as the Manteca Unified director of business services.

The district for the past number of years has been steady at 22,000 plus students. If charter schools are peeling off high numbers, it is being countered by housing growth the district continues to experience despite the Great Recession.

Other districts haven’t been as fortunate. The loss of students in Escalon prompted that district to create a charter school and to start advertising aggressively the positive advantages of sending a child to their charter academy.

Ripon Unified Superintendent Louise Johnson told her board this week that the district may have to “market” the quality education she noted Ripon schools offer in order to retain their own students and/or attract students from other districts.

The California Charter School Association noted there were 484,000 charter school students in California during the 2011-12 school year attending 1,063 charter schools. That is one out of roughly 12 of the 6 million school-aged students in California. There also were 70,000 more students on waiting lists for charter schools.

Eight years ago only one in every 20 school-aged students in California were enrolled in charter schools.

Breitenbucher noted that options for students are a good thing as traditional public schools sometimes aren’t the best fit.

“We’re monitoring it,” she said. “It could become a problem down the road but it isn’t now.”

Competition from charter schools is one reason why Superintendent Jason Messer indicted last month Manteca Unified is looking at options to put the Lindbergh School campus into use in perhaps a supporting role for storage and such.

If not, under state law a charter school could take over the campus due to the fact it has been sitting unused for several years.