Environmental and Engineering Services

Alden’s Environmental and Engineering Services group is widely recognized as being highly effective in resolving flow and fisheries related environmental issues associated with FERC licensing and NPDES project permitting.

Our scientists and engineers have designed and evaluated numerous types of fish protection systems for water intakes as well as upstream and downstream fish passage facilities at dams and hydroelectric facilities. In addition to optimizing biological performance, the Group specializes in resolving O&M problems associated with intake screening such as debris management, icing, siltation, and head loss using a multidisciplinary approach combined with physical and computational flow modeling and testing.

§316(b) and Cooling Water Intake Structures (Learn more)

  • Fish protection technology assessments, including engineering, costs, and biological effectiveness
  • Strategic planning for §316(b) compliance
  • CWIS fish protection technology design, development, and evaluation
  • Impingement and Entrainment (I&E) assessments
  • Addressing Operation and Maintenance (O&M) concerns

Fish Protection and Passage (Learn more)

  • Upstream and downstream fish passage design and evaluation
  • Laboratory and field studies of fish protection and passage technologies
  • Physical and Computational Fluid Dynamic (CFD) modeling to map flow and optimize fish passage designs

Hydropower - Environmental Projects (Learn more)

  • Desktop fish I&E assessments
  • Theoretical (desktop) estimation of turbine and total project survival
  • Fish-friendly hydro turbine design
  • Field evaluation of fish survival and bypass efficiency
  • Instream flow studies
  • Juvenile eel surveys
  • Federal Energy Regulatory Commission (FERC) licensing support and agency consultation

Other Services

  • Design, development, and testing (biological and operational performance) of hydrokinetic and waver power technologies
  • Thermal plume and dye studies
  • Fish sampling and tracking
  • Hydroacoustics (telemetry, DIDSON, infrasound)

Environmental Testing Facilities (Learn more)


Fish Holding
(Learn more)