MARTINEZ -- The school board is expected on Monday to appoint a principal at John Muir Elementary to replace Lauran Hawker, who resigned Wednesday.

The special board meeting is 3 p.m. at the district office, 921 Susana St.

Hawker, who was principal for two years, is leaving Martinez to become principal of an elementary school in the Napa Valley Unified School District, Martinez Superintendent Rami Muth said.

Hawker's departure just three weeks before school starts on Aug. 21 is "clearly disruptive," said Muth, who declined to name the appointee before the board meeting.

However, she said the district grooms the three assistant principals so they are prepared to take on leadership roles at a school when the time comes.

"We have some people within our own district that allow us to address moves of this kind," Muth said.

Lisa P. White covers Martinez and Pleasant Hill. Contact her at 925-943-8011. Follow her at Twitter.com/lisa_p_white.