Montgomery County Executive Isiah Leggett, shown in this April 11, 2013, file photo, is planning to hire three new department heads. (Jeffrey MacMillan)

With the 2014 political season behind him, County Executive Isiah Leggett is preparing to hire three new department heads whose portfolios will include everything from leaf collection and affordable housing to road maintenance and watershed protection.

Leggett is expected to fill directorships in the departments of transportation, environmental protection and housing and community development by early next year, replacing top officials who have been with him since the beginning of his first term in 2007. He did not mention the names of possible appointees but said he has been considering candidates and will focus fully on the openings after Nov. 25, when he will return from an economic development trip to India, which begins this week.

“These are major decisions with a fairly significant impact long beyond my tenure in office” said Leggett, who on Tuesday was overwhelmingly elected to a third term in office.

Environmental protection chief Robert Hoyt departed in May. Housing and Community Development Director Rick Nelson is retiring in mid-December. And officials say Transportation Director Arthur Holmes Jr. is also expected to retire, although they declined to speak on the record because no formal announcement has been made.

Council members and community stakeholders have strong ideas about what qualities each of the officials’ replacements should bring to their posts.

Holmes, 83, who did not return phone messages, is a former two-star Army general who has also served as chairman of the Montgomery Planning Board and public works director. His transportation department, with an annual budget of $205 million, has responsibilities that include snow removal, road and tree maintenance and the Ride On bus system.

Holmes has drawn criticism for his department’s continuing emphasis on road construction at a time when a rising millennial generation is driving less and placing a premium on living near public transit. The county hopes to start building a bus rapid transit (BRT) network in the next few years, most likely beginning with segments of Rockville Pike and Route 29.

Kelly Blynn, who leads a “next generation of transit” campaign for the Coalition for Smarter Growth, credits the department with launching the new system of Bikeshare stations around the county. But she said Montgomery is lagging behind Northern Virginia, where a walkable Arlington and the new Silver Line hold strong appeal for those seeking less car-centric lives.

“A director who understands transit, walking and cycling will be key for the county’s economic development,” Blynn said.

Holmes’s expected retirement has also revived discussion about formation of a quasi-independent transit authority to lead the BRT project. It was among the recommendations of a transit task force that Leggett commissioned in 2011. Leggett said no decision has been made about a separate transit authority, which would require state approval.

Nelson, 75, has been housing director since 2007, running a $158 million agency that oversees code enforcement, affordable housing and landlord-tenant relations. He said the department has done “a fairly decent job” of providing low-cost housing despite challenges posed by the economy.

The county has long required that any new housing development have at least 12.5 percent of the units set aside as moderately priced. Nelson said a zoning ordinance approved by the County Council this year provides more incentives to developers by permitting residential construction at higher densities if they set aside 15 percent of their units as affordable.

Some housing advocates say the department needs to upgrade its performance, especially in protecting the interests of tenants, whose presence in the county has grown from 10 percent to about a third of the population in recent years.

Matt Losak, executive director of the Montgomery Renters Alliance , said the next housing director has to hold landlords more accountable for unreasonable rent increases and evictions without cause.

“We need somebody who is not just a representative of the landlord and development industry,” Losak said.

Hoyt, a former Maryland environmental official, served as Montgomery environmental protection director for seven years.

He received generally high marks from council members and conservationists as a principled and scientifically sound operator of a $130 million agency that oversees trash and recycling, watershed protection and stormwater management.

Council Member Roger Berliner (D-Potomac-Bethesda), who chairs the transportation and environment committee, said the focus of the department had for a long time been stormwater and that the emphasis needed to shift to a broader spectrum of issues, such as energy efficiency and climate change.

The county government has committed to getting 100 percent of its energy from renewable sources by 2020 and to reduce greenhouse gas emissions 80 percent by the year 2050.

“My hope is that our next director of environmental protection will have equal facility with those set of issues and commitment to those sets of issues so that we make significant progress,” Berliner said.