Before 2009, water supply and wastewater service tariffs were determined annually on the basis of historical financial data, used as the main determinant of financial needs for the following year.  

In 2008 WSRA initiates the first 3-year tariff review process (2009-2011), based on far-sighted projections of expenditures, capital investments and allowance for sufficient equity capital to attract investors to the sector. The tariffs were set in advance over the base year price levels (2008) for three years of the review period.  

In 2011 WSRA improves the 2012-2014, tariff process by developing a Regulatory Business Plan (RBP), which was easier to use, and improved the reporting database.

The next tariff processes are a continuation of the 2012-2014, tariff methodology, where necessary modifications have been made to the RBP and the reporting format.