EVERETT — A new YMCA in Everett and major improvements at Lake Stevens High School are among the construction projects that have been disrupted by a labor strike that began earlier this week.

Members of the International Union of Operating Engineers Local 302 went on strike after voting to reject a contract proposal.

The strike, which started Tuesday, affects tower cranes, concrete pumpers, dirt work, pavers, hoisting and materials handlers, and other heavy equipment operators on job sites in the Puget Sound region, from King County north to Whatcom County, the Olympic Peninsula, and Central Washington.

Union leaders said Local 302 asserted its rights under the National Labor Relations Act to withhold its labor from contractors who are part of the Associated General Contractors master labor agreement.

“After months of negotiations our members voted down two tentative contract offers and have elected to withhold our labor and picket job sites until a more agreeable offer is presented,” said Daren Konopaski, the local’s international vice president and business manager, in a prepared statement.

“We have a long-standing relationship with the AGC and our contractors, and we are hopeful a resolution will be reached soon,” Konopaski wrote.

Associated General Contractors posted on its website that it has offered a 15 percent increase over three years.

“Throughout the bargaining process AGC of Washington has committed to bargaining in good faith with a goal to reach a ratified agreement,” it wrote.

Construction on the YMCA project in Everett began earlier this summer.

In June, a few hundred people gathered to watch the ceremonial shoveling of the first few inches of dirt on the site at 4730 Colby Ave.

The new 60,000 square-foot building will include two swimming pools. A leisure pool will contain a lazy river, a warm water therapy area, and provide zero-depth entry for access for people with disabilities.

An indoor track, a permanent space for the Big Brother Big Sister of Snohomish County program, a full-size gym, group exercise classes and a drop-in daycare also are planned.

The new building is estimated to cost $33 million. The YMCA purchased the 8.1-acre site in 2015 for $3.3 million from the Everett School District. It arranged for a southern portion of its land to be used as a neighborhood park for the Glacier View area.

In Lake Stevens, an $87 million high school upgrade began in June. It will include a three-story classroom building, a student hub and an athletic building. Voters in 2016 approved a $116 million bond for the high school overhaul and a new elementary and preschool.

Work is expected to finish in 2020. It will be done in phases while students are in school, as well as in the summer.

“It is our understanding that the (Local) 302 operators strike is impacting a great deal of school districts who are building and modernizing schools,” said Jayme Taylor, a Lake Stevens School District spokeswoman. “We are working with Cornerstone, our contractor, to … prioritize Lake Stevens High School campus readiness for students and teachers.”

Eric Stevick: 425-339-3446; stevick@heraldnet.com.