Eden Prairie school leaders are drawing new lines in the most extensive school boundary change the city has seen in a decade.

The changes would affect at least 500 students and likely many more, depending on how the new lines are drawn.

Though tied to the district's plan to move from K-4 elementary schools to a K-6 model, the boundary changes are driven largely by a desire to desegregate all elementary schools in a district that finds itself increasingly diverse.

Like other outer-ring suburban school districts, Eden Prairie now has more students qualifying for lunch subsidies.

The city also has experienced an influx of immigrants from Somalia and Spanish-speaking countries, which has produced a ripple effect in the schools.

For weeks, a task force made up of parents and school district staff has been creating maps of potential new boundaries.

In all, 9,700 students attend the Eden Prairie public schools, with just under 5,000 in the elementary schools.

As part of the shift from K-4 to K-6 schools, the district is adding a sixth elementary school to be housed in the Oak Point Intermediate School in the coming years. That building also will be home to the district's only magnet school -- Eagle Heights Spanish Immersion School. The district is ending the fifth- and sixth-grade program at Oak Point.

The boundaries task force came a step closer to finishing their work earlier this week when school leaders chose to make the new elementary school a traditional, neighborhood school instead of a citywide magnet program.

"We are very close to done," said Patricia Magnuson, a leader of the Boundaries & Transition task force.

Boundary changes would not take effect until fall 2011.

Task force members have said that it would be easier to balance all the schools by race if the new elementary program draws students from the immediate area, instead of from all over the city.

A magnet school actually could have a reverse effect on attempts to integrate the schools, by attracting affluent and white parents, Eden Prairie school officials said.

Of the four K-4 schools, Forest Hills Elementary, in the northeast part of the city, has the highest concentration of low-income students, Magnuson said.

Forty-two percent of students at Forest Hills qualify for lunch subsidies while 9.5 percent of Cedar Ridge Elementary students meet the criteria for a free or reduced-price lunch.

"Our goal was to lower that [gap]," Magnuson said.

For help, the district called in a heavy-hitter: Myron Orfield.

A nationally known expert on school desegregation, he's advising the task force and district leaders on their work.

"He told us what we instinctively knew and pointed to a lot of research that shows it's important for schools to be indistinguishable by race and by poverty level," Magnuson said. "A lot of research shows that kids in integrated schools do better."

At the school board meeting, task force members presented numbers reflecting what kind of enrollment mix they would need to improve the achievement gap between poor students and others, and between white students and students of color.

One figure would require all schools to have similar populations, plus or minus 3 percent. Another showed 7 percent.

School board member John Estall asked what the district would gain by choosing the smaller margin which would be more disruptive to neighborhoods.

"I want to know that we're going to get a commitment that I'm going to get a substantial benefit," he said. "'Cause we're asking these families to give up their neighborhood or whatever it is and we ought to be able to say to them clearly, here's the benefit.

"Otherwise, if I'm a parent that's in a school that's really working well for me, and now you're going to ask me to go to a school maybe where it's not working as well right now. Why am I doing this? This is about my child. And we need to have a story to say why that's a good idea."

Magnuson said the task force hopes to finish the map in August, so members can present the proposed boundaries at the Aug. 24 school board meeting.

Drafts of the map will then appear on the district's website and at school district headquarters, making them available for feedback from the public.

Allie Shah • 612-673-4488