 Sage was a field officer and spokesperson for Forest and Bird before being elected as councillor for the Selwyn-Banks Peninsula Regional Constituency of Environment Canterbury at the 2007 local elections.She lost her seat when the Environment Canterbury Council were replaced by Commissioners on 1 May 2010.In October 2010 she was appointed as a community member to the Selwyn-Waihora Zone Water Management Committee of Canterbury Water Management Strategy (CWMS).