The latest school district mergers proposed under Maine’s 3-year-old consolidation law have a lot in common.

The merged districts would all enroll about 1,000 students. They’d all comprise towns that voted against previous consolidation plans. They’d all take on the alternative organizational structure rather than the regional school unit structure most consolidated districts have adopted.

And their ability to move forward depends on passage of a consolidation law overhaul pending in the Legislature.

The Maine Department of Education has received three proposals in recent weeks to merge school districts in Aroostook, Kennebec and Washington counties. School officials in those areas hope to put the plans out to voters this spring. If they pass at the polls, the mergers would take effect July 1.

In central Maine, the Winthrop and Fayette school systems plan to merge their administrative offices while leaving curriculum, transportation and some money management to the individual towns. The new unit would enroll 975 students, according to current state data.

“It allows these communities to continue their municipal school budgets,” said Fayette Superintendent Briane Coulthard, “so you kind of preserve the cultural practices of these communities.”

Voters in Fayette and Winthrop rejected a proposal in January 2009 to combine their school administration with the four-town Maranacook-area school district’s.

An alternative organizational structure that involves Fayette and Winthrop would be a more natural step for the towns, said John Mitchell, chairman of the Winthrop Board of Education. While they might start out sharing only a few services, he said the partnership could expand with time.

Some 11 towns in the Machias area are proposing a single unit called the Machias Bay Area School System that would enroll 1,006 students, according to state education data.

In Aroostook County, Mars Hill-based School Administrative District 42 and Fort Fairfield-based SAD 20 are proposing to form an alternative organizational structure.