The Old Rochester Regional District School Committee approved changes to its regional agreement for the first time in 35 years on Tuesday night.

A string of amendments to the agreement governing school district procedures and municipal collaborations was unanimously approved at an ORR School Committee meeting on April 13. They were the first revisions to the agreement since 1986, according to Superintendent Michael Nelson, despite state recommendations to review the document every five years.

“It was important for us not only to have a regional agreement that is in compliance with legal statutes and requirements, but also an agreement that preserves local control,” Nelson said, commending the efforts of members of the School Committee to revamp the agreement.

The first of the approved amendments will smooth over issues in evaluating yearly budgets which spur from fluctuations in school enrollment, according to committee member Heather Burke.

“Year in and year out, they see these major fluctuations in their assessments,” Burke said, “and that causes them not to be able to budget, not to be able to plan for other town activities and projects.”

Budgets are currently determined based on annual enrollment assessments, Burke said, a method that often leaves towns “scrambl[ing] to fit that into their budget puzzle” on short notice. The amended practice will see budgets determined on a three year rolling average, allowing towns to “plan more appropriately.”

The amendments will also spell out a new system for apportioning money to the capital stabilization fund based on a five-year rolling average of enrollment.

“It’s just something that’s really necessary for maintaining the regional facilities,” Burke said.

The agreement will also be updated in accordance with the “one person, one vote” state law to ensure proportional representation of each town within the district, even as populations increase or decrease over time.

Elected school committee officials will also see changes to their term times, with start dates switching from mid-May to July 1 in an effort to ease committee transitions at the end of the school year.

The amendments have received preliminary approval by the Massachusetts Department of Elementary and Secondary Education, according to Nelson.

However, in order to be finalized, the Agreement requires public approval in Marion, Mattapoisett and Rochester, Burke said. The amendments will appear as part of the warrant presented in each town’s upcoming Town Meeting.

“It does need to pass in every town,” Burke said. “And so I am really hoping that everyone from this committee will go to their town meetings and support it.”