Boise trustees have OK’d a big increase in the school property tax rate — an estimated 18%. The increase widens a stark property tax gap between Idaho’s two largest school districts — Boise and West Ada — and illustrates dramatic policy differences between the adjoining Treasure Valley districts. Boise trustees have the unusual power to increase or decrease property tax collections. Unlike Boise, West Ada cannot simply collect “M&O” property tax levies for everyday operations. The second comes back to the complicated property tax relief law passed by the Legislature in 2023.