Institute a 4-day school week. It decreases spending on gas for buses, electricity costs used in operation of all computers/technology.
There are California districts who have instituted 4-day work weeks which are typically in remote areas. A 4-day school week requires special approval by the California Legislature, as well as it requires collective bargaining. Although there might be transportation savings, there is no savings from the largest part of the budget, salary/personnel, because the same number of instructional and contact minutes are still required within a 4-day week period. Many employees would dislike an on-going 4 day week when it would require 10 hour duty days.