Reducing turbulence and associated air entrainment is generally considered advantageous in the engineering design of fish passage facilities.
Fish passage facilities are an effective means for mitigating the effect of barriers (e.g., dams, weirs, and road crossings) on migrating fishes.
Salmon can travel up the Snake River as far as Hells Canyon Dam, using the fish passage facilities of the four lower Snake River dams, leaving the Clearwater, Grande Ronde and Salmon river to sustain spawning salmon.
The original fish passage facilities of the dam continually experienced problems from the beginning of operation in 1966, and introduced species that prey on young smolt often gather at the base of the dam, which reduced the population of outmigrating juvenile salmon into the Pacific.
In this case, the colonists dispersed naturally into the newly accessible habitat, and the primary reintroduction cost was the construction, operation, and maintenance of the fish passage facilities.
Yet IUCN, for one, has filed a complaint.A study in 2011 comparing two North American rivers and the Mekong concluded that decades of research would be needed to ensure that specialised fish-passage facilities "actually meet the needs of these diverse fisheries of the Mekong".
He attributed much of the building boom to passage of the Facilities Act in 2000 that made $8.6 billion available for construction, with $6 billion of that earmarked for the state's 30 poorest districts.
Debris passage through expressway facilities is defined as the designed sedimentation volume of debris flow from valley to waterway under the expressway.
Table 6 Modified points given to attributes based on the original grading standard of KEC Open image in new window Note D is the diameter of lateral drains and B is the width of waterway box for the scoring index of debris passage through expressway facilities.
