The emergency service says the First Nation community's chief and council have requested that about 1,000 vulnerable residents be evacuated from the area.
Andrew Morrison, a spokesman with Emergency Management Ontario, said the province is planning the evacuation with provincial ministries, federal departments and potential host communities.
Further north, residents from Kashechewan also remain out of their homes due to flooding. Attawapiskat and Kashechewan have both been through flooding and housing crises in the past.
Morrison said a few residents and band officials have stayed behind in the community to look after local infrastructure.
Residents who have left are staying in several different communities, including Kapuskasing, Thunder Bay and Cornwall.
"Efforts are being made to reunite Kashechewan family members who were sent to different host communities," Morrison said.