It should be no surprise that St. Paul School Superintendent Meria Carstarphen is the all-but-official next head of the Austin, Texas, School District. If the Austin Board of Trustees finalizes her hire, as expected, after a 21-day waiting period for community input, she’ll leave St. Paul at the end of this school year.

Like many of her peers in urban education, she has spent about three years on the St. Paul job before apparently moving on to the Texas position. That timeframe is about average for a big-city school chief, according to a recent study by the Council on Great City Schools. And like many urban superintendents before her, Carstarphen is on her way to a higher-paying job in a larger district. The 85,000-student Austin district will pay her $285,000 to run it, a raise of $90,000.

In a statement, Carstarphen, 39, said that she has been honored to work in St. Paul and leaves with mixed emotions. She described the district as having come “a long way’’ during her three years.

She became one of the youngest superintendents in the nation when she arrived in St. Paul in 2006 following a stint as accountability director for the Washington, D.C., public schools. As a relatively young, ambitious school leader, her decision to take the Austin job is predictable.

She leaves behind a mixed record. Carstarphen earned good grades on some important organizational, leadership and curriculum changes, but on student results she merits an incomplete. In the past three years, the 38,000-student district has seen little progress in closing the achievement gap between students of color and their white peers.

During her tenure, she has focused on using data to improve achievement and on sharing student information with the wider community. She wisely helped move the district toward a more uniform curriculum so that students could receive the same basics in reading and math from school to school. And she developed a clear vision and strategy for the district.

Carstarphen should also be commended for building ties with the business and nonprofit communities. Travelers Companies Inc. recently announced a $1.4 million contribution to fund several school initiatives.

Carstarphen had critics, which is typical in large districts. Some teachers and staff members complained that she was an inflexible taskmaster, and she ran into community opposition on several school closing and restructuring issues.

In a recent meeting with the Editorial Board, she talked about the need to make up to $10 million in permanent cuts, even if additional state or federal funding comes through. Because of declining enrollment and the need to redirect limited resources, she argued that those adjustments were necessary for the long-term financial health of the district.

Ideally a superintendent would spend a minimum of four to six years with a district facing the kind of challenges seen in St. Paul. Now her expected departure will force the district to conduct another leadership search — a situation that almost always causes some systemwide disruption. While districts are looking for new leaders, important projects are often put on hold.

It appears that those challenges will now fall to the next superintendent in St. Paul.