Final plans to stop three-tier education in Dorset and reduce 1,000 surplus places will be decided this week.
Councillors will discuss new proposals for schools in Swanage and Wool after months of public consultation.
Sessions were held to discuss how a primary-secondary model could work, and local people formed groups to advise the council. St Mary's Catholic First School in Wool and Wool CE VA First School will become primaries.
There are two new options for Swanage: to make three new primaries from four schools, or to make all of them primaries.
John England, Dorset County Council's head of learning and school improvement, said: "We have a serious problem ... with pupil numbers in Purbeck falling and the probability of schools being forced to close because they will not have enough pupils to survive.
"There are many changes being made to children and young people's education, particularly for 14- to 19-year-olds. Purbeck needs a school system that gives all children in the area the same experiences and opportunities to make the most of their lives as the rest of Dorset.
"During the first round of consultation earlier this year, a number of concerns were raised by residents in Swanage and Wool, particularly around parental preference. We believe the new proposals address many of these concerns and reduce the majority of surplus places, giving Purbeck a school system that will thrive for many years to come."
Further public consultations will be held in the new year. KM.