Many of the school libraries have after school family times.  If they do, and your children attend the school, you are welcome to check out books available in that building within the time frames they have set up.  School libraries are smaller and must serve the needs of students and teachers first.  Because of space and funding, school collections are smaller and limited to the age groups within the building.  School librarians teach other classes as well as being librarians, thus have limited time to work with their collections.  It might be more expensive for the public to use the school buildings with so many schools spread over such a large area.  In a small community that had very few schools, it might be an excellent idea.