Los Angeles County supervisors are expected to conduct a public hearing Tuesday for the proposed development of nearly 140 homes next to Castaic High School.

The project entails developing an area of three existing single-family residential dwelling units into 157 lots comprised of 137 homes on Sloan Canyon Road at Canyon Hill Road, including two flag lots, four open space lots, two private recreation lots and 14 public facility lots on 186 acres, according to a report from the county Regional Planning Department.

The applicant of the project, which includes Allen B. Russell and others, would also need the county’s permission to remove 23 oak trees and encroach on six other oak trees, as well as would require a zone change to allow for residential development and a conditional use permit to authorize construction within a hillside area and onsite grading of more than 100,000 cubic yards of earth.

“The project will result in a high-quality residential development that will improve the overall value and quality of life of the surrounding community,” according to the report, which adds that the proposal also promotes the county’s vision for improving “the quality of life in unincorporated areas.”

In a previous review of the plan before regional planners, Russell said the housing proposal would be “great for the community” of Castaic, particularly with the addition of Castaic High School, which opened for classes last year.

The project has received support from the Castaic Town Council, according to Jessica Chambers, vice president of the council.

“The letter was sent in support (of the project) as long as they adhered to the (Castaic Area Community Standards District),” she said. “It’s a good project with lots of free space. (The applicant) was a pleasure to work with; they listened to the needs of the community.”

After a public hearing on Aug. 26 and another on Sept. 9, Regional Planning commissioners voted to recommend approval of the proposal to the Board of Supervisors — a recommendation that includes “the board act on the commission’s strong desire to see an on-site affordable housing set-aside as part of the project,” according to the report.

Regional Planning Department staff have detailed that the project would generate “significant increases” in property tax revenue and would help the county in meeting its housing needs by developing underutilized lots.