Waters, 30, moves across from Partners Group's direct and relationship marketing agency, Partners Andrews Aldridge, where she was also the head of planning. During her time there, Waters continued to work within Partners BDDH as a senior planner.
Waters replaces Malcolm White, who has relinquished his role to concentrate on his position as the head of strategy. White said: "Kate was my first hiring when I set out to create a new planning department and so it's really pleasing to see how brilliantly she's done."
Waters has been with the Partners Group for four years. She joined from Ammirati Puris Lintas where she worked on Nestle Rowntree, Rover and NatWest.
She joined as a senior planner working on The Guardian and Transport for London, and in 2000 won an IPA Effectiveness award for her work in Co-op food retailing.
She was recently responsible for converting a series of new- business wins including the Evening Standard and The British Heart Foundation.
Simon Toaldo, the managing director of Partners BDDH, said: "Kate did a great job at Partners Andrews Aldridge. Her appointment also frees Malcolm up to do what he is best at: big thinking and new business."