Appendix 5. Fish and boat pass channel – studies at the Public Works Research Institute, Japan
Five fish and boat pass channel designs were studied at the Water Resources and Hydraulic Division of Public Works Research Institute (PWRI) in Japan at the end of 1990’s. Four of the models were built to a scale of 1 to 5, and one of the models was actual size. The purpose of the actual size model was to study fish ascending in the model. The models were named Model 1, 2, 3,4, and 5. Model 1 was developed at the Oulu Polytechnics, Finland in the middle of 1990’s (Pohjamo 1995). The other models were based on Model 1 (Fig. A5.1). All the models are actually modifications of Denil fishways. Compared to a standard Denil fishway, these models are larger in channel width and smaller in relative water depths d/b with d denoting the depth of flow and b the free opening. The desired velocity distribution and energy dissipation were achieved by special stripes in the middle of the opening (Models 1 and 2) or by open slots in the middle of the vanes (Models 3, 4, and 5).
In all the models, the baffles were fixed at 45° to the bed of the channel. Experiments were performed on slopes of 4% and 5% for Models 1 to 4 and for Model 5 the slope was 10%. Discharges in Models 1 to 4 were 20, 30, and 40 l/s. The discharges for the studies on Model 5 were 50, 75, and 100 l/s. The discharges were measured by inductive discharge measurement devices located in the supply conduits of the flumes. Velocities were measured with a mini current meter with a data collector at the section of fully developed flow. Water surface profiles were measured with a point gauge along the length of the channel. During the course of the studies, photographs were also taken. The results of the studies are presented in Gurram and Kashiwai 1999.
Reports and papers
Gurram SK & Kashiwai J (1999) Fish and boat pass channel – hydraulic model studies and fish ascending tests. Water Resources and Hydraulic Engineering Division, Dam Department. Public Works Researck Institute, Ministry of Construction. Technical Memorandum of PWRI no 3678. 88 p.
Gurram SK & Pohjamo T (1999) Hydraulic assessment of a fish and boat pass channel. Hydropower & Dams, Issue Three, p. 65-67.
Pohjamo T (1995) A combination of fishway and boat channel. Proc. Int. symposium on fishways "95 in Gifu, Japan Oct. 24-26. p. 371-376.