Evaluation of the Challawa Gorge Dam spillway channel using a physical model

The Challawa Gorge Dam is situated at Karaye, about 90km south east of Kano, Nigeria. The purpose for the dam include, irrigation, improvement of water supply to Kano city and other towns and settlements along the river system as well as fisheries and livestock development and recreation. Models of hydraulic structures have been found to be effective tools for optimizing the design of water conveyance facilities and water control works. This paper is a brief account of the model study of the Challawa Gorge Dam Spillway channel. A 1:50 model of the spillway and tailwater basin of the dam was built and tested under controllable conditions at the National Water Resources Institute, Kaduna. A point gauge equipped with a vernier was used to measure flow depths at three selected sections of the tailwater basin. The results of the test showed that the proposed tailwater basin is adequate.