As we are all aware, Electricity and Water tariff increases in Johannesburg will take effect from the 1st July 2016. The fact that the invoices are presented one month after (i.e. costs for June will be invoiced in July), the effect of the increase will not be felt until the August invoice, and more likely in September, when the first full months readings is taken.
For schools in Johannesburg, the City of Johannesburg publishes all the Municipality's increases, from 2013/2013 and includes the 2016/2017 increases. See this Link COJ Tariffs