Hydraulic model study of Poutu Stream bed intake Tongariro power development scheme / L. Fellerman.

Cover title.

"July, 1968."

Summary -- 1. Introduction -- 2. The Models -- 2.1 Tests on the 1/9.2 scale model -- 2.2 Tests on glace slope and erosion of river bed -- 2.3 Models tests on 1/30 scale model -- 3. The effect of the tunnel restrictor -- 4. Possible reduction in depth of stilling basin -- 5. Conclusions -- 6. Acknowledgements -- 7. References.

Two models of a Stream Bed Intake, one sectional model to a scale of 1/9.2 and the other a complete model of the intake structure to a scale of 1/30, have been constructed and studied in the laboratories of the British Hydromechanics Research Association. The intake is to be sited on the Tongariro River and the abstracted water would be fed, by tunnel and aqueduct to Lake Roto Aira. The structure forms one part of the overall scheme of the Tongariro Hydro-electric Power Development, for the North Island, New Zealand. The aims of the study were to investigate the ability of the intake to limit the abstracted water to a maximum design flow of 2790 cubic feet per second and an extreme flow in flood conditions of 2930 cubic feet per second. This limitation of flow in flood conditions is necessary to prevent overtopping of the aqueduct canal. Preliminary examinations were made of the design and the modification incorporated in the first model. The first study led to sizing of the clearance above the side weirs and to the determination of the capacity of each section of the intake structure. In the second model the number of sections in the intake was reduced from five to four and a restrictor for the tunnel outlet was designed and tested.

GRETA POINT: 627.8.09(931.219) HYD