Perforated-Pipe Water Intake for Fish Protection

Since a major concern in the design of pumping station water intakes is the possibility of damage by fish drawn into the facility, some kind of screening system must be installed to minimize or eliminate this possibility. The potentially adverse impact of water intakes is resolved by the implementation of physical screens, which exclude all debris, including fish. The germane difficulties of screens, i.e., the necessity of lowering the approach velocity, poor velocity distribution across the screen, and danger to fish are overcome by the installation of a perforated-pipe inlet with an added internal perforated sleeve. The benefits of such a device, i.e., relative ease of maintenance, uniform approach velocity, uniform inflow, and protection for fish, cannot be equalled by ordinary means of physical screening. For water intakes up to 100,000 gal/min, the inner sleeve type of perforated-pipe intake provides a viable solution to the problem of screening.