While building a highway or a dam may provide significant benefits to mankind through improved economic or mobility options, such structures can impact aquatic species in a more negative fashion. Creating artificial barriers in the natural environment may result in unnatural consequences for native fish populations. HDR's highly skilled fisheries scientists can assess existing barriers, develop plans to avoid impacts on aquatic environments during construction projects, and create innovative ways to add, remove, or adjust fish passageways.
A barrier to stream can be any obstacle that prevents fish from moving either up or downstream, including such manmade features as dams, floodgates, bridges, causeways, and roads. Barriers can change water velocity and depth as well as water quality with minimal to monumental impacts, including species extinction. In some cases, a barrier may be needed to prevent fish from entering an area where they might be injured or negatively impact the environment. Design of barriers to prevent fish entry is a recognized HDR specialty.
HDR can design passage over stream barrier systems or design to remove a barrier while incorporating ecological, regulatory and sustainability issues. Our fisheries experts use advanced designs to build systems that allow or restrict fish passage, depending on project requirements. Examples include structural configurations that create hydraulic conditions to allow fish to swim up and over a barrier and fish trap and transport systems. Screening municipal water treatment plant intakes or irrigation diversions is an example of a design that must be in strict compliance with regulatory guidelines.
Examples of fish passage and barrier related services provided by HDR include:
Assessment, monitoring and design
Collection and sorting facilities
Culvert remediation and analysis
Upstream fish passage design
Dam removal
Juvenile fish bypass system design
Water supply intake and diversion screen design