The ownership of Western Power Distribution (WPD) changed on 6th September 2002 when the Mirant Corporation of Atlanta sold their 49% stake in WPD to the Pennsylvania Power & Light Corporation (PPL Co.) of Allentown, Pennsylvania which already held a 51% share of the company. Western Power Distribution is therefore now wholly owned by PPL Co.

Western Power Distribution orginated in the South Western Electricity Board (SWEB). In 1995, Southern Company, a large American energy business, acquired SWEB for $1.8 billion. Southern later sold 51% of the business to PPL Co. and spun off the Mirant Corporation which retained the other 49%. South Western Electricity plc operated under the SWEB brand name until 30 September 1999 when it changed its trading name to Western Power Distribution.

In October 2000, Western Power acquired Hyder plc, the former Welsh multi-utility company which owned the electricity distribution business serving South and West Wales, as well as the assets of what was once Welsh Water. The water assets were in turn sold on to Glas Cymru in May 2001. Glas Cymru is a "not-for-profit" company financed by loans (bonds) rather than having shareholders, and was set up with the express purpose of acquiring Dwr Cymru/Welsh Water from Western Power. However, we understand that as part of this deal WPD reserved the right to buy Llanishen and Lisvane reservoirs back from Glas Cymru, as they had identified them as being a suitable site for making money through property development.

This may ultimately benefit the shareholders of the Pennsylvania Power and Light Corporation, whereas the residents of Cardiff stand to lose a unique and beautiful amenity.