The G1 news portal cites an army major as saying that 170 troops arrived Thursday morning.
Army engineers are expected to arrive later in the day to help repair highways, roads and bridges damaged by the floods.
Calls to the Army for details went unanswered.
Espirito Santo's civil defense department says 21 people died in mudslides or floodwaters and close to 50,000 people were forced from their homes.
In neighboring Minas Gerais state, floods and mudslides have killed 18 people and about 4,000 people were forced to leave their homes.