Some local boat cross the Abay River near the Blue Nile Falls. The Blue Nile Falls is a waterfall on the Blue Nile River in Ethiopia. They are known as Tis Abay in Amharic, translated, means "smoking water" They are situated on the upper course of the river, about 30 km downstream from the town of Bahir Dar and Lake Tana. The falls are considered one of the best known tourist attractions of Ethiopia. The falls are estimated between 37 and 45 meters high, consisting of four streams that originally varied from a thread in the dry season of more than 400 meters wide in the rainy season. Regulation of Lake Tana now reduces the variation somewhat, and since 2003 a hydroelectric station has taken much of the flow of the falls except during the rainy season. The Blue Nile Falls have isolated the ecology of Lake Tana ecology from the rest of the Nile, and this isolation has played a role in the evolution of endemic fauna of the lake.