Some Manhattan parents are scrambling to stop a plan to move 150 Harlem Success Academy 5th-graders into a building on the Upper West Side. Critics fear the plan could make the Success Academy students, most of whom live in Central and East Harlem, eligible to attend Upper West Side middle schools once they reach 6th grade. Others say the move may jeopardize federal magnet programs at two of the small elementary schools in the building.

E-mail alerts about the proposal went out Thursday to many parents of students in District 3, which spans Manhattan’s west side from 59th to 122nd streets.  The e-mails urged parents to attend a March 15 public hearing and speak out in opposition to the plan.

According to one e-mail, the Harlem Success Academy students are largely from Districts 4 and 5, but the plan would transfer them into District 3 during 5th grade. “Once they are housed in a D3 building, they become eligible for D3 middle schools,” read the e-mail. “Our strong D3 middle schools could become an appealing option for these out-of-district families at a time when we are already facing a serious middle school seat crunch.”

The plan seeks to co-locate the 5th grades of Harlem Success Academy 2 and 3 inside a building on West 111th Street shared by PS 185 and PS 208. PS 185, known as the Early Childhood Discovery and Design Magnet School, serves Pre-K through 2nd grade. PS 208, known since 2011 as the Alain L. Locke Magnet School for Environmental Stewardship, serves grades 3 through 5. Also sharing the building is the K-5 Harlem Link Charter School.

A notice sent from the Parent Teacher Association of PS 185/208 warns the plan could cause a space crunch that would curtail growth at the two small schools. Both are among eight District 3 schools now sharing an $11 million magnet grant designed to improve education and increase enrollment. Some fear that the magnet grants might even be at risk if the school doesn't have space to meet the mandates.

District 3 parents on the education council wonder why the schools don't use space in their home districts.

"We identified 12 schools in districts 4 and 5 that have adequate space to place 150 5th-graders," said Noah Gotbaum, a member of the District 3 Community Education Council. He said parents asked Education Department official Elizabeth Rose at a meeting on Friday why District 3 had to accommodate the children. "This is the plan," she said, according to Gotbaum. "This is what was decided was best for the kids."

Last year Gotbaum led an ultimately unsuccessful battle to keep Upper West Success from opening in the Brandeis High School building.

The March 15 hearing on the co-location proposal begins 6 p.m. in the auditorium of PS 208, located at 20 West 112th Street. A 5 p.m. press conference is planned prior to the hearing.

Several Success Academy school locations have caused controversy around the city. A group of parents in Williamsburg are suing the charter organization charging they have not done enough outreach to attract neighborhood Latino families. The Brooklyn Paper reported the charter group has now "stepped up its marketing efforts," hosting pizza parties and asking parents to sign affadavits that might be used in court, to show their support for the school. More than 700 families have applied for the Success school set to open in Williamsburg; another 950 have applied to a sister school in Cobble Hill.