A member of Wikwemikong First Nation, Mandamin was a survivor of the Canadian Indian residential school system and cofounder of the Mother Earth Water Walkers.
[7] The water walk movement began in 2003 after grandmother Josephine Mandamin became concerned over the pollution happening to the lakes and rivers across Turtle Island.
[11] The work continues through a group called Nibi Emosaawdamajig (Those Who Walk for the Water), led by Shirley Williams and her niece Elizabeth Osawamick.
[12] Mandamin was the Chief Commissioner of the Anishinabek Nation Women's Water Walk Commission, a member of the Great Lakes Guardian Council.
[16] On January 26, 2018, Josephine was awarded the Governor General's Meritorious Service Decoration in recognition for her contributions to Indigenous leadership and reconciliation.
[7] In 2022, Sir John A. Macdonald Senior Public School in Brampton was renamed "Nibi Emosaawdang” (meaning water walker in English) in honour of Mandamin.
[19] Autumn Peltier, Josephine Mandamin's grand-niece, was inspired to continue her aunt's work by becoming a water protector and advocate.