Saco’s planning and development director has resigned to take a job leading an effort to prepare Maine communities to deal with the state’s aging population.

Peter Morelli, who has been with the city of Saco for 27 years, will lead the AARP Maine Age Friendly Community Project, which is designed to help Maine communities prepare for the state’s changing demographics.

Maine’s median age – 43.5 years – is the highest in the United States, in part because the state also has a dwindling younger population, according to 2012 U.S. Census data.

The state’s proportion of people age 65 and older – 17 percent – is second only to Florida’s 18.2 percent.

Maine has the nation’s highest proportion of baby boomers – 29 percent of its 1.3 million residents were born between 1946 and 1964 – and they’re turning 65 at a rate of 18,250 a year, according to AARP Maine.

By 2030, more than 25 percent of Mainers will be 65 or older, magnifying existing shortages in transportation, housing, health care, long-term care and elder services.

The Portland Press Herald/Maine Sunday Telegram is examining aging issues in an ongoing series, “The Challenge of Our Age.”

Morelli said in a resignation letter addressed to the city manager that his new position will involve planning, economic development and public policy.

He will leave his position in Saco on Oct. 8.

During his time in Saco, Morelli launched a project that made the city one of the first in the state to examine how to be an age-friendly community.

The project looks at how to address various issues, from transportation to social inclusion.

In his resignation letter, Morelli said his work in the city included helping write two comprehensive plans, rewriting the zoning ordinance, streamlining the land use approval office, building two business parks, attracting Amtrak service and building a train station, and attracting more than $4 million in grant funding.

“It’s been a pleasure working for a great city for 27 years,” he said.