THE LAKES DISTRICT
The part of the rift that forms 1230m at L. Chamo in the south to approximately 1800m at Awash River watershed is known as the Lakes District. Seven lakes of tectonic or volcano-tectonic origin occur in this district. From south to north they are L. Chamo, Abaya, Awassa, Shala, Abjata, Langano, and Zway .One of the routes from Addis Abeba, the capital, to the Lakes District is with in this rift valley, running SSW from Mojo for 700 km to the Kenyan border.
The Lakes District is bounded on the East by the Arsi-Bale massifs and in the west by the Shewan plateau. The region is hot and dry with an annual rainfall of 1000mm.The area is densely populated and completely deforested.
As the Zway-Shala and Awassa lake basins are all closed the rivers in the area flow into the lakes. Though L, Shala and Awassa have no out lets, L. Awassa must be losing water by underground seepage.
Lake Zeway is a slightly alkaline lake in the central section of the Ethiopian Great Rift Valley. It lies to the east of Zeway town, 160 km south-west. The lake is 29 km long and 20 km wide, with a maximum depth of 8 m (mean c.2.5 m), and a seasonal variance of 0.5–1.2 m. Within 10 km to the east and west of the lake are higher faulted ridges. To the north, the land rises gently to 1,670 m where it meets the watershed of the Awash river and Koka dam reservoir.
There are several islands, some inhabited, the largest probably for 1,000 years and supporting an Orthodox Christian community. The Zay are a small ethnic group of about 5,000 people in the country They are also known as the Zeway or Laki.(Rower). They live on the islands of Ziway, south of Addis, and engage mainly in fishing. The Zay language belongs to the Southern branch of the Ethiopian Semetic language family and is closely related to the languages spoken by the neighboring Gurage ethnic group. The language is one of the extinct Semitic languages of Ethiopia. We will make a 3hours round boat trip to the island to visit the Zay community to explore, Language and culture and the Church on the island.
Geologically, the area is flooded by thick lacustrine sediments underlain by older ignimbrites and basalts. Recent volcanic centers are abundant. The evidence of lake terraces shows that in the recent past the lakes were once more extensive than at present, and indeed were once joined together as Abaya-Chamo basin to the south, and Zway –Shala and Awassa basin to the north .It was assumed that these major basins were separated as a result of late Pleistocene (<1myear) earth movements which involved different systems of faulting and/or drier climates.