Fish Pass Design

Fish Pass Design

The team at Fishtek are highly experienced in the design of a wide range of fish passes, having designed over 200 fish passes to date.

Complete range of fish passes designed

We specialise in the design of all modern fish passes and fish easements, including:

  • Technical baffle fish passes
  • Traditional pool and traverse passes
  • Vertical slot passes
  • Natural fishways/rock ramps and naturalised bypass channels
  • Hybrid passes
  • Lamprey passes
  • Pre-barrages
  • Low-cost easements
Fish Pass Design | Fish Pass Fabrication

Innovative Approach

Fish Pass Project innovation

Our involvement in fish pass design starts at the very first stage of a project, with the feasibility study and options appraisal process, whereby the preferred fish passage improvement at a site is identified.

The default best option for improving river ecology is almost always barrier removal, however, in the absence of this as a feasible option, the preferred fish passage solution for the site will be determined. We have carried out assessments of this kind at hundreds of barriers previously and have a comprehensive understanding of all of the factors that dictate the preferred fish passage option at a site.

One of our most valued skills is the ability to take an innovative approach to solve fish passage problems. This allows us to identify and design solutions at difficult sites or find new solutions for sites where more traditional design approaches have failed.

Previous project examples

Previous Fish Pass project examples of this innovative approach include a hinged Larinier fish pass (the only one in the UK), a hybrid fish pass and fish lift/lock that provides one of the largest fish passage facilities in the world (on the Mekong River), a specialised pre-fabricated design solution for a fish pass at a site with very limited space for construction and a bespoke, innovative downstream smolt chute and passage facility.


Site specific approach

Tailored to the unique characteristics of each site

For each project and site that we are involved with, we liaise with developers, regulatory bodies and civil engineers to identify and develop the most appropriate and cost-effective approach that is tailored to the specifics of the site and fish species present.

All of our design work is informed by relevant fish passage research and advances in the status of our knowledge surrounding fish migration, passage and the effectiveness of different fish passage solutions.

Full hydraulic modelling

CAD engineering drawings and modelling

We provide full hydraulic modelling and calculations for the preferred design at a site and a complete CAD facility (including 3D solid-model engineering drawings) is available in house for design work, as well as the capability to produce full civil construction drawings.

We are able to design fish passes for an extremely wide range of sites, from large lowland rivers to small upland streams with flows ranging from a few litres per second to thousands of cubic metres per second. In our experience there is always a solution to a fish passage problem.

All of our design work is under-pinned by the principles of Construction, Design and Management (CDM) and we can undertake various roles under CDM including acting as Principal Designer and Principal Contractor.

Project management

We manage entire fish pass projects

In addition to our design experience, we are also able to project manage entire fish pass projects, including gaining any consents necessary for the construction of a fish pass.

We have previously carried out this work for numerous projects, including sites where the weir or barrier of concern is historically listed, and sites within SACs, SSSIs and World Heritage areas. Gaining the appropriate consents often requires other assessments to also be carried out, such as ecological surveys, flood risk assessments (FRAs) and geomorphology assessments.

Fishtek are able to carry out these assessments as part of the consenting process, either through the use of in-house expertise or by working with trusted sub-contractors.

Case Studies

Fish Pass Design


Fish Pass Design

Unlocking the Severn

Fish Pass Design