Part of the Semien, Dembiya is bordered on the south by Lake Tana, on the southwest by Takusa, on the west by Chilga, on the north by Lay Armachiho, and on the east by Gondar Zuria.

A survey of the land in this woreda shows that 64% is arable or cultivable and another 25% under irrigation, 6% pasture, 4% forest or shrubland, and the remaining 1% is considered degraded or other.

[4] The location of the Battle of Gur Amba, where Ras Kassa (the later Emperor Tewodros II) defeated Dejazmach Goshu Zewde 27 November 1852, lies within the modern boundaries of this woreda.

"Thousands of heads of cattle, whole silos of grain, and significant tracts of grazing and farmland have been washed away," according to IRIN.

A notable minority in this woreda are the Weyto, who are thought to be the earliest surviving ethnic group to settle around Lake Tana; they number 480 or 0.22% of the population.