The Karimenu II Dam diversion tunnel is about 400m long and is intended to serve as a diversion of the water to allow for the Dam construction and also to transport the abstracted raw water and compensation back to the river. The tunnel is arch shaped and has an excavated height of 5.1m and width of 4.2m and has a slope of 1.46%. The internal finished diameter will have a height and width of 4m and 3m respectively. Excavation is done using the drill and blast method.