High Quality Content by WIKIPEDIA articles! The Whakamaru to Brownhill Road transmission line is a double-circuit 400 kV capable transmission line constructed by Transpower to increase the capacity of the National Grid between the southern Waikato and the city of Auckland. The line runs from the Whakamaru sub-station near the Whakamaru Power Station, over a distance of 186 kilometres (116 mi) to the new Brownhill Road substation near Whitford in southeastern Auckland. The line will initially be operated at 220 kV. From Brownhill Road, 220 kV underground cables connect the line to the Pakuranga sub-station in eastern Auckland. The project was the subject of considerable controversy and protest during the planning and approval stages. Construction of the line started in February 2010, and the line was commissioned on 30 October 2012. The transmission line forms the major part of a wider North Island Grid Upgrade project with a forecast cost to completion of $894 million.