The Tana Water Services Board (TWSB) is one of the eight Water Services Boards created under the Ministry of Water and Irrigation following the enactment of the Water Act (2002). TWSB covers 38 Subcounties (Excluding Gatanga) in 6 counties of Nyeri, Murang´a, Kirinyaga, Embu, Tharaka-Nithi and Meru covering an area of 19,169km2 with a population of 4,238,469 (2009 census).The estimated figure for 2015 is 4,537,000 projected from the 2009 population census with 16% urban and 84% rural. 40 per cent of the area is either arid or semi-arid. About 80 per cent of the residents live in the rural areas. Currently, 37 per cent of the population receives their water from water supply schemes that were inherited from the Ministry of Water and Irrigation.