He joined Far North Holdings as executive chairman in 1999 and was made chief executive in 2008.
Nicolson resigned from the council-owned company after 12 years to take up a position as chief executive of the Northland Regional Council [NRC].
During his time at the NRC between 2012 and 2022, he was a driving force behind significant projects in Te Tai Tōkerau, including flood control schemes in Kāeo, Kaitāia, Panguru and Whangārei, and a water resilience fund to improve drinking water supplies to communities not on public supplies.
He also played a key role in the creation of Northland Inc, Northland’s economic development and regional tourism organisation.
Nicolson strove to bring unity to the region’s governance system, and advanced joint decision-making through initiatives such as the Iwi and Local Government Chief Executives Forum and the establishment of two Māori seats on the NRC.