On or before the first day of September, the county treasurer of each county and the city treasurer of each city, the county tax assessor, or the official or officials in each county and city who are charged by law with the responsibility of determining or estimating revenues to be available for the operation of government in that county or city, shall certify in writing through the county or city superintendent of education in charge of schools in that county or city to the county or city board of education the assessed valuation of property on which taxes are to be collected during the next fiscal year and the amount of school taxes which may reasonably be expected to be derived from assessed valuations during that year. This official or these officials shall also certify in writing through the county or city superintendent of education to the county or city board of education the amount which may be expected to be available from any other fund or funds set aside by law or ordinance or in any other manner for school purposes in that county or city.