Following his federal political career, Siddon remained active as a consultant, lecturer and corporate board member. He speaks frequently on the political challenges of combating global climate change and the long range implications for water supply management. Siddon was the founding Chair of the Okanagan Water Stewardship Council, and a member of the RBC Blue Water Advisory Panel. In 2007, he was awarded a Doctorate of Laws from the University of British Columbia | Okanagan, received the University of Alberta Honour Award in 2009, the 2010 UBC Alumni Award of Distinction, and was the 2017 recipient of the University Of Toronto Engineering Alumni Hall of Distinction Award.