Its source is on the slopes of the Nyandarua Plateau below the Aberdare Range; it ends its course in lake Bogoria.

[2][3] In its upper reaches, the Waseges flows through regions of intensive coffee cultivation where heavy use is made of chemical fertilizers and pesticides.

The planned irrigation scheme was based on a single large concrete-lined canal feeding just one area.

Scheduled for launch in 1983, there were delays due to protests from the local people, and the project was not completed until the 1987/1988 season.

[9] Before 2003 the river was illegally diverted for irrigation upstream in the Subukia area, causing it to dry up downstream during a period of drought.