Dozens of parents and several D.C. Council members called on city officials Thursday to slow their effort to overhaul public school boundaries, arguing that education leaders should focus on improving schools before redrawing maps.

“I just want to be clear that we need to take time,” said D.C. Council member and mayoral candidate David A. Catania (I-At Large), speaking during a six-hour hearing on the boundary effort. He said that further study is needed to understand the long-term impact of the latest proposal on the city’s schools.

“It’s not a not-now, not-ever proposition, and it’s not catering to folks who have a particular point of view,” said Catania, chairman of the council’s Education Committee. “It’s making sure we don’t do this in a way that spooks our parents and this very tenuous confidence that we’re trying to build.”

D.C. Council member Muriel Bowser (D-Ward 4), her party’s mayoral nominee, said she would like to find an immediate way to deal with acute overcrowding at Northwest Washington schools so that other schools have time to improve before boundary changes take effect.

The council has no official role in approving the boundary revisions, as that is entirely the responsibility of Mayor Vincent C. Gray (D). Gray is expected to announce a boundary plan in September that would take effect in fall 2015.

But because Gray’s term ends in January, implementing his plan — which is certain to be controversial — will fall to his successor. Catania said he believes that a new law would bar any changes from taking effect earlier than fall 2016, and Bowser said she wants to see millions of dollars allocated for new middle schools before the boundary changes take effect.

D.C. Deputy Mayor for Education Abigail Smith, who has led the effort, pushed back against the suggestion that the city should wait. She argued that it makes no sense to hold off on fixing a system left “irrational and inefficient” by decades of school closures and demographic change.

“It’s simply unrealistic to think that we can improve schools without addressing the core questions of how students are assigned to them,” Smith said, adding that the city’s patchwork of boundaries and feeder patterns has made it difficult for education officials to do long-term planning and establish programs that meet community demands.

“Waiting for a new administration won’t make it easier,” Smith said, calling on the council and the city to have “the courage and conviction to make much-needed changes.”

Schools Chancellor Kaya Henderson, making her first public remarks about the boundary overhaul, said she’s been troubled by criticism that the city is redrawing maps before improving schools. She said principals and teachers are working every day to improve schools.

“Nobody believes that just by changing boundaries and feeder patterns are we going to improve D.C. Public Schools,” Henderson said. “I hope people see this as not just a solution, or the solution, but part of a series of strategically sequenced interventions that we need to do to build a system of neighborhood schools.”

Thursday’s hearing drew many parents seeking to advocate for their families and neighborhoods. Parents from the Crestwood neighborhood, east of Rock Creek Park, argued that the boundary proposal is unfair because it would cut them out of two sought-after Northwest schools: Alice Deal Middle and Wilson High. Parents from Mount Pleasant, another east-of-the-park neighborhood, praised the proposal because it would maintain their access to those schools.

But several broad questions arose from the testimony, including whether — and how — the city can overhaul school boundaries and student-assignment policies without simultaneously considering the significant role of charter schools.

“If our goal is to have citywide student-assignment policies that are coherent and efficient, charter schools must be part of the conversation,” said David Grosso (I-At Large), who said he supports the direction of the boundary proposal and believes it is necessary but wants to see more concrete proposals for coordinating with charters.

Currently, the D.C. Public Charter School Board approves charters without considering their impact on existing schools and often without knowing where they will be located.

Charter advocates say that such independence has been critical to their success and must be protected; critics say that the lack of coordination makes rational long-term planning impossible, especially given that charters are growing quickly and now enroll 44 percent of city students.

“Thoughtful planning around school boundaries is meaningless if it only involves half our public school system,” said Caryn Ernst, a Capitol Hill parent.

Henderson included herself among the critics, saying she was “looking for a little more” on charter-DCPS coordination from the boundary proposal. A new science- and technology-focused charter school recently decided to move in across the street from a traditional school that emphasizes science and technology, she said — a sign of the need for greater coordination.

All but a handful of the parents who testified represented areas west of the Anacostia River, mirroring participation in recent community meetings on the issue. Those have skewed heavily toward residents of Northwest Washington.

D.C. Council member Yvette M. Alexander (D-Ward 7) said that many in her ward view the boundary proposal as a move toward “new-age segregation” by encouraging families to attend neighborhood schools, which tend to be much lower-performing east of the Anacostia River than in areas west of Rock Creek Park.

“What are we left with?” Alexander said. “We’re left with the short end of the stick.”